KR20220167157A - Method and apparatus for transmitting and receiving downlink control information and data in a wirelss communication system - Google Patents

Abstract

The present disclosure relates to a 5^th generation (5G) or pre-5G communication system for supporting a higher data transmission rate beyond a 4^th generation (4G) communication system, such as long term evolution (LTE). In accordance with embodiments of the present disclosure, a method for operating a terminal in a wireless communication system includes the following steps of: receiving a first control signal from a base station; generating a second control signal based on the first control signal; and transmitting the second control signal to the base station.

Description

Method and apparatus for transmitting and receiving downlink control information and data in a wireless communication system

The present disclosure relates generally to wireless communication systems, and more particularly to methods and apparatus for transmitting and receiving downlink control information and data in wireless communication systems.

Efforts are being made to develop an improved ^5th generation ( ^5G ) communication system or a pre-5G communication system in order to meet the growing demand for wireless data traffic after the commercialization of a 4th generation (4G) communication system. For this reason, the 5G communication system or pre-5G communication system has been called a Beyond 4G Network communication system or a Post LTE system.

In order to achieve a high data rate, the 5G communication system is being considered for implementation in a mmWave band (eg, a 60 gigabyte (60 GHz) band). In order to mitigate the path loss of radio waves and increase the propagation distance of radio waves in the ultra-high frequency band, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used in 5G communication systems. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed.

In addition, to improve the network of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud RAN), and an ultra-dense network , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and reception interference cancellation etc. are being developed.

In addition, in the 5G system, Advanced Coding Modulation (ACM) methods such as FQAM (Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation) and SWSC (Sliding Window Superposition Coding) and advanced access technology FBMC (Filter Bank Multi Carrier) ), Non Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA) are being developed.

Based on the above discussion, the present disclosure provides a method and apparatus for transmitting and receiving downlink control information and data in a wireless communication system.

According to various embodiments of the present disclosure, in a method of operating a terminal in a wireless communication system, receiving a first control signal from a base station, generating a second control signal based on the first control signal, and the A method comprising transmitting a second control signal to the base station is provided.

According to various embodiments of the present disclosure, a terminal in a wireless communication system includes a transceiver and at least one processor, wherein the at least one processor receives a first control signal from a base station, and in response to the first control signal Based on the above, a terminal configured to generate a second control signal and transmit the second control signal to the base station is provided.

Various embodiments of the present disclosure provide a method and apparatus for transmitting and receiving downlink control information and data in a wireless communication system.

Effects obtainable in the present disclosure are not limited to the effects mentioned above, and other effects not mentioned may be clearly understood by those skilled in the art from the description below. will be.

1 illustrates a wireless communication system according to various embodiments of the present disclosure.
2A illustrates a basic structure of a time-frequency domain, which is a radio resource domain in which a data or control channel is transmitted in a wireless communication system according to various embodiments of the present disclosure.
2B illustrates a slot structure in a wireless communication system according to various embodiments of the present disclosure.
3 illustrates an example of setting a bandwidth portion in a wireless communication system according to various embodiments of the present disclosure.
4 illustrates an example of setting a control region of a downlink control channel in a wireless communication system according to various embodiments of the present disclosure.
5A illustrates an example of a structure of a downlink control channel in a wireless communication system according to various embodiments of the present disclosure.
5B illustrates an example of a case in which a terminal may have a plurality of PDCCH monitoring positions within a slot in a wireless communication system according to various embodiments of the present disclosure.
6 illustrates an example of a DRX operation in a wireless communication system according to various embodiments of the present disclosure.
7 illustrates an example of base station beam allocation according to TCI state setting in a wireless communication system according to various embodiments of the present disclosure.
8 illustrates an example of TCI state allocation for a PDCCH in a wireless communication system according to various embodiments of the present disclosure.
9 illustrates an example of a TCI indicating MAC CE signaling structure for PDCCH DMRS in a wireless communication system according to various embodiments of the present disclosure.
10 illustrates an example of beam configuration of a control resource set and a search space in a wireless communication system according to various embodiments of the present disclosure.
11 illustrates an example of a method in which a base station and a terminal transmit and receive data in consideration of a downlink data channel and a rate matching resource in a wireless communication system according to various embodiments of the present disclosure.
12 illustrates an example of a method for selecting a receivable control resource set in consideration of priority when a terminal receives a downlink control channel in a wireless communication system according to various embodiments of the present disclosure.
13 illustrates an example of frequency axis resource allocation of a PDSCH in a wireless communication system according to various embodiments of the present disclosure.
14 illustrates an example of time axis resource allocation in a wireless communication system according to various embodiments of the present disclosure.
15 illustrates an example of time axis resource allocation according to subcarrier intervals of a data channel and a control channel in a wireless communication system according to various embodiments of the present disclosure.
16 illustrates an example of beam configuration and activation of a PDSCH in a wireless communication system according to various embodiments of the present disclosure.
17 illustrates an example of a PUSCH repetitive transmission type in a wireless communication system according to various embodiments of the present disclosure.
18 illustrates an example of a radio protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation in a wireless communication system according to various embodiments of the present disclosure.
19 illustrates an example of antenna port configuration and resource allocation for cooperative communication in a wireless communication system according to various embodiments of the present disclosure.
20 illustrates an example of configuration of downlink control information (DCI) for cooperative communication in a wireless communication system according to various embodiments of the present disclosure.
21 illustrates an example of an enhanced PDSCH TCI state activation/deactivation MAC-CE (enhanced PDSCH TCI state activation/deactivation MAC-CE) structure in a wireless communication system according to various embodiments of the present disclosure.
22 illustrates an example of an RLM RS selection process in a wireless communication system according to various embodiments of the present disclosure.
23 illustrates an example of a process of generating a PDCCH repeatedly transmitted through two TRPs in a wireless communication system according to various embodiments of the present disclosure.
24 illustrates an example of a multi-TRP based PDSCH SFN transmission method in a wireless communication system according to various embodiments of the present disclosure.
25 illustrates an example of an enhanced PDCCH TCI state activation/deactivation MAC-CE (enhanced PDCCH TCI state activation/deactivation MAC-CE) structure in a wireless communication system according to various embodiments of the present disclosure.
26A illustrates an example of a terminal operation for primary beams of a PDCCH and a PDSCH in a wireless communication system according to various embodiments of the present disclosure.
26B illustrates an example of an operation of a base station for primary beams of a PDCCH and a PDSCH in a wireless communication system according to various embodiments of the present disclosure.
27A illustrates an example of a structure of a terminal in a wireless communication system according to various embodiments of the present disclosure.
27B illustrates an example of a structure of a base station in a wireless communication system according to various embodiments of the present disclosure.

Terms used in the present disclosure are only used to describe a specific embodiment, and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art described in this disclosure. Among the terms used in the present disclosure, terms defined in general dictionaries may be interpreted as having the same or similar meanings as those in the context of the related art, and unless explicitly defined in the present disclosure, ideal or excessively formal meanings. not be interpreted as In some cases, even terms defined in the present disclosure cannot be interpreted to exclude embodiments of the present disclosure.

In various embodiments of the present disclosure described below, a hardware access method is described as an example. However, since various embodiments of the present disclosure include technology using both hardware and software, various embodiments of the present disclosure do not exclude software-based access methods.

Hereinafter, embodiments of the present disclosure will be described in detail with accompanying drawings. Hereinafter, the present disclosure describes embodiments for transmitting and receiving downlink control information and data in a wireless communication system, but is not limited to each embodiment and applies to all or part of one or more embodiments proposed in the present disclosure. It may also be possible to use a combination of the examples for a frequency resource setting method corresponding to another channel. Therefore, the embodiments of the present disclosure can be applied through some modifications within a range that does not significantly deviate from the scope of the present disclosure as determined by a person having skilled technical knowledge.

In addition, in describing the present disclosure, if it is determined that a detailed description of a related function or configuration may unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present disclosure, and may vary according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout this specification.

The wireless communication system has moved away from providing voice-oriented services in the early days and, for example, 3GPP's high speed packet access (HSPA), LTE (long term evolution or E-UTRA (evolved universal terrestrial radio access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's high rate packet data (HRPD), UMB (ultra mobile broadband), and IEEE's 802.17e. evolving into a communication system.

In the LTE system, which is a representative example of a broadband wireless communication system, OFDM (orthogonal frequency division multiplexing) is adopted in downlink (DL), and SC-FDMA (single carrier frequency division multiple access) in uplink (UL) method is being adopted. Uplink refers to a radio link in which a user equipment (UE) or mobile station (MS) transmits data or control signals to a base station (eNode B (eNB) or base station (BS)), and downlink refers to a base station It means a radio link that transmits data or control signals to this terminal. In addition, the above-described multiple access scheme distinguishes data or control information of each user by assigning and operating time-frequency resources to carry data or control information for each user so that they do not overlap each other, that is, to establish orthogonality. Let it be.

The 5G communication system, which is a communication system after LTE, must support services that simultaneously satisfy various requirements so that various requirements such as users and service providers can be freely reflected. Services considered for the 5G communication system include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), ultra reliability low latency communication (URLLC), etc. there is

eMBB aims to provide a data transmission rate that is more improved than that supported by existing LTE, LTE-A or LTE-Pro. For example, in a 5G communication system, an eMBB must be able to provide a peak data rate of 20 Gbps in downlink and a peak data rate of 10 Gbps in uplink from the viewpoint of one base station. In addition, the 5G communication system should provide the maximum transmission rate and at the same time provide the user perceived data rate of the increased terminal. In order to satisfy these requirements, various transmission/reception technologies may be improved, including a more advanced multi-input multi-output (MIMO) transmission technology. In addition, while signals are transmitted using a transmission bandwidth of up to 20 MHz in a 2 GHz band in the LTE system, the 5G communication system uses a frequency bandwidth wider than 20 MHz in a frequency band of 3 to 6 GHz or 6 GHz or higher, thereby increasing the data transmission rate required by the 5G communication system. can satisfy

At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. In order to efficiently provide IoT, mMTC requires access support for large-scale terminals within a cell, improved coverage of terminals, improved battery time, and reduced terminal cost. Since the Internet of Things is attached to various sensors and various devices to provide communication functions, it must be able to support a large number of terminals (eg, 1,000,000 terminals/km2) in a cell. In addition, UEs supporting mMTC are likely to be located in shadow areas that are not covered by cells, such as the basement of a building due to the nature of the service, so they require wider coverage than other services provided by the 5G communication system. A terminal supporting mMTC must be configured as a low-cost terminal, and requires a very long battery life time such as 10 to 16 years because it is difficult to frequently change the battery of the terminal.

Finally, in the case of URLLC, it is a cellular-based wireless communication service used for a specific purpose (mission-critical). For example, remote control of robots or machinery, industrial automation, unmaned aerial vehicles, remote health care, and emergency situations. A service used for emergency alert or the like may be considered. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, a service supporting URLLC must satisfy air interface latency of less than 0.5 milliseconds, and at the same time must satisfy requirements of a packet error rate of 10-5 or less. Therefore, for a service supporting URLLC, the 5G system must provide a smaller transmit time interval (TTI) than other services, and at the same time allocate wide resources in the frequency band to secure the reliability of the communication link.

Three services of the 5G communication system (hereinafter, it can be mixed with the 5G system), that is, eMBB, URLLC, and mMTC, can be multiplexed and transmitted in one system. At this time, different transmission/reception techniques and transmission/reception parameters may be used between services in order to satisfy different requirements of each service.

In the following description, terms referring to signals, terms referring to channels, terms referring to control information, terms referring to network entities, terms referring to components of a device, etc. are used for convenience of description. it is exemplified Accordingly, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

In addition, although the present disclosure describes various embodiments using terms used in some communication standards (eg, 3rd Generation Partnership Project (3GPP)), this is only an example for explanation. Various embodiments of the present disclosure may be easily modified and applied to other communication systems.

1 illustrates a wireless communication system according to various embodiments of the present disclosure. 1 illustrates a base station 100, a terminal 120, and a terminal 130 as some of nodes using a radio channel in a wireless communication system. Although FIG. 1 shows only one base station, other base stations identical to or similar to the base station 100 may be further included.

Base station 100 is a network infrastructure that provides wireless access to terminals 120 and 130 . The base station 100 has coverage defined as a certain geographical area based on a distance over which signals can be transmitted. The base station 110 includes 'access point (AP)', 'eNodeB (eNB)', '5G node (5th generation node)', 'next generation nodeB (next generation nodeB)' in addition to the base station. , gNB)', 'wireless point', 'transmission/reception point (TRP)', or other terms having equivalent technical meaning.

Each of the terminal 120 and terminal 130 is a device used by a user and communicates with the base station 100 through a radio channel. In some cases, at least one of the terminal 120 and the terminal 130 may be operated without user involvement. That is, at least one of the terminal 120 and the terminal 130 is a device that performs machine type communication (MTC) and may not be carried by a user. Each of the terminal 120 and terminal 130 is a 'user equipment (UE)', a 'mobile station', a 'subscriber station', a 'remote terminal' other than a terminal. )', 'wireless terminal', 'user device', or other terms having an equivalent technical meaning.

The base station 100, terminal 120, and terminal 130 may transmit and receive wireless signals in a mmWave band (eg, 28 GHz, 30 GHz, 38 GHz, and 60 GHz). At this time, in order to improve the channel gain, the base station 100, the terminal 120, and the terminal 130 may perform beamforming. Here, beamforming may include transmit beamforming and receive beamforming. That is, the base station 100, the terminal 120, and the terminal 130 may give directivity to a transmitted signal or a received signal. To this end, the base station 100 and the terminals 120 and 130 may select serving beams 112, 113, 121 and 131 through a beam search or beam management procedure. . After the serving beams 112, 113, 121, and 131 are selected, communication may be performed through a resource having a quasi co-located (QCL) relationship with a resource transmitting the serving beams 112, 113, 121, and 131. there is.

If the large-scale characteristics of the channel carrying the symbol on the first antenna port can be inferred from the channel carrying the symbol on the second antenna port, the first antenna port and the second antenna port are said to be in a QCL relationship. can be evaluated. For example, a wide range of properties are delay spread, doppler spread, doppler shift, average gain, average delay, spatial receiver parameter may include at least one of them.

2A illustrates a basic structure of a time-frequency domain, which is a radio resource domain in which a data or control channel is transmitted in a wireless communication system according to various embodiments of the present disclosure.

Specifically, FIG. 2A is a diagram showing a basic structure of a time-frequency domain, which is a radio resource domain of a 5G system.

In FIG. 2A , the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 101), which is one orthogonal frequency division multiplexing (OFDM) symbol (or discrete Fourier transform spread OFDM (DFT-s-OFDM) symbol) on the time axis. (102) and one subcarrier (103) in the frequency axis. In the frequency domain, N _SC ^RBs (eg, 12) consecutive REs may constitute one resource block (RB, 104). In addition, N _symb ^subframe consecutive OFDM symbols in the time domain may constitute one subframe (110).

2B illustrates a slot structure in a wireless communication system according to various embodiments of the present disclosure.

Specifically, FIG. 2B is a diagram illustrating a slot structure considered in a 5G system.

2B shows an example of a structure of a frame 200, a subframe 201, and a slot 202. One frame 200 may be defined as 10 ms. One subframe 201 may be defined as 1 ms, and thus one frame 200 may consist of a total of 10 subframes 201 . Also, one slot (202, 203) may be defined with 14 OFDM symbols (ie, the number of symbols per slot N _symb ^slot =14). One subframe 201 may be composed of one or a plurality of slots 202 and 203, and the number of slots 202 and 203 per one subframe 201 is a set value for the subcarrier interval, μ(204). , 205).

In the embodiment of FIG. 2, the slot structure is shown when μ = 0 (204) and μ = 1 (205) as the subcarrier interval setting value. When μ = 0 (204), one subframe 201 may consist of one slot 202, and when μ = 1 (205), one subframe 201 may consist of two slots ( 203). That is, the number of slots per subframe (N _slot ^{subframe, μ} ) may vary according to the set value μ for the subcarrier interval, and accordingly, the number of slots per frame (N _slot ^{frame, μ} ) may vary. N _slot ^subframe,μ and N _slot ^frame,μ according to each subcarrier interval setting μ can be defined as [Table 1] below.

Next, a demodulation reference signal (DMRS), which is one of the reference signals in the 5G system, will be described in detail.

DMRS may consist of several DMRS ports, and each port uses code division multiplexing (CDM) or frequency division multiplexing (FDM) to maintain orthogonality so as not to interfere with each other. However, the terms for the DMRS may be expressed in other terms depending on the user's intention and the purpose of using the reference signal. More specifically, the term DMRS is only presented as a specific example to easily explain the technical content of the present disclosure and help understanding of the present disclosure, and is not intended to limit the scope of the present disclosure. That is, it is obvious to those of ordinary skill in the art that the technical idea of the present disclosure can be implemented even for reference signals.

[Bandwidth Part (BWP)]

Next, the bandwidth part (BWP) setting in the 5G communication system will be described in detail with reference to the drawings.

3 illustrates an example of setting a bandwidth portion in a wireless communication system according to various embodiments of the present disclosure. Specifically, in FIG. 3, the UE bandwidth 300 is set to two bandwidth parts, that is, bandwidth part # 1 (BWP # 1) 301 and bandwidth part # 2 (BWP # 2) 302. show an example The base station may set one or a plurality of bandwidth parts to the terminal, and may set the following information for each bandwidth part.

Of course, it is not limited to the above example, and various parameters related to the bandwidth part may be set in the terminal in addition to the setting information. The information may be transmitted from the base station to the terminal through higher layer signaling, for example, radio resource control (RRC) signaling. At least one bandwidth part among one or a plurality of set bandwidth parts may be activated. Whether or not the set bandwidth portion is activated may be semi-statically transmitted from the base station to the terminal through RRC signaling or dynamically transmitted through downlink control information (DCI).

According to some embodiments, a terminal prior to RRC (Radio Resource Control) connection may receive an initial bandwidth portion (Initial BWP) for initial access from a base station through a Master Information Block (MIB). More specifically, in the initial access step, the terminal receives system information (remaining system information; RMSI or System Information Block 1; may correspond to SIB1) necessary for initial access through the MIB. PDCCH for receiving can be transmitted Setting information on a control resource set (CORESET) and a search space may be received. The control area and search space set by MIB can be regarded as identity (ID) 0, respectively. The base station may notify the terminal of setting information such as frequency allocation information, time allocation information, and numerology for the control region #0 through the MIB. In addition, the base station may notify the terminal of configuration information about the monitoring period and occasion for control region #0, that is, configuration information about search space #0, through the MIB. The terminal may regard the frequency domain set as the control domain #0 acquired from the MIB as an initial bandwidth part for initial access. At this time, the identifier (ID) of the initial bandwidth part may be regarded as 0.

The setting for the portion of the bandwidth supported by 5G can be used for various purposes.

According to some embodiments, when the bandwidth supported by the terminal is smaller than the system bandwidth, it can be supported through the bandwidth portion setting. For example, the base station can transmit and receive data at a specific frequency position within the system bandwidth by setting the frequency position (configuration information 2) of the bandwidth part to the terminal.

Also, according to some embodiments, the base station may set a plurality of bandwidth parts to the terminal for the purpose of supporting different numerologies. For example, in order to support both data transmission and reception using a subcarrier spacing of 15 kHz and a subcarrier spacing of 30 kHz to a terminal, two bandwidth parts may be set to subcarrier spacings of 15 kHz and 30 kHz, respectively. Different bandwidth parts may be frequency division multiplexed, and when data is to be transmitted/received at a specific subcarrier interval, a bandwidth portion set at a corresponding subcarrier interval may be activated.

Also, according to some embodiments, for the purpose of reducing power consumption of the terminal, the base station may set bandwidth parts having different bandwidths to the terminal. For example, when a terminal supports a very large bandwidth, for example, a bandwidth of 100 MHz and always transmits and receives data with the corresponding bandwidth, very large power consumption may occur. In particular, monitoring an unnecessary downlink control channel with a large bandwidth of 100 MHz in a non-traffic situation may be very inefficient in terms of power consumption. For the purpose of reducing power consumption of the terminal, the base station may set a bandwidth part of a relatively small bandwidth, for example, a bandwidth part of 20 MHz for the terminal. In a situation where there is no traffic, the terminal can perform a monitoring operation in the 20 MHz bandwidth part, and when data is generated, it can transmit and receive data in the 100 MHz bandwidth part according to the instructions of the base station.

In the method for setting the bandwidth part, terminals before RRC connection (Connected) can receive setting information on the initial bandwidth part (Initial Bandwidth Part) through a Master Information Block (MIB) in an initial access step. More specifically, the terminal is a control region (Control Resource Set, CORESET) can be set. The bandwidth of the control region set by the MIB may be regarded as an initial bandwidth portion, and the UE may receive a physical downlink shared channel (PDSCH) through which the SIB is transmitted through the initial bandwidth portion set. The initial bandwidth portion may be used for other system information (Other System Information, OSI), paging, and random access in addition to the purpose of receiving the SIB.

[Change bandwidth part (BWP)]

When one or more bandwidth parts are configured for the terminal, the base station may instruct the terminal to change (or switch, transition) the bandwidth part using a bandwidth part indicator field in the DCI. For example, in FIG. 3, when the currently active bandwidth part of the terminal is bandwidth part #1 301, the base station may instruct the terminal with the bandwidth part #2 302 as a bandwidth part indicator in the DCI, and the terminal receives The bandwidth part change can be performed with the bandwidth part #2 302 indicated by the bandwidth part indicator in the DCI.

As described above, since the DCI-based bandwidth part change can be indicated by the DCI that schedules the PDSCH or PUSCH, when the UE receives the bandwidth part change request, the PDSCH or PUSCH scheduled by the corresponding DCI is grouped in the changed bandwidth part. It must be possible to receive or transmit without To this end, the standard stipulates the requirements for the delay time (TBWP) required when changing the bandwidth part, and may be defined as follows, for example.

In the following, a downlink control channel in a 5G communication system will be described in more detail with reference to the drawings.

4 illustrates an example of setting a control region of a downlink control channel in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 4 is a diagram illustrating an example of a control region (Control Resource Set, CORESET) in which a downlink control channel is transmitted in a 5G wireless communication system. 4 shows a UE bandwidth part 410 on the frequency axis and two control regions (control region # 1 401 and control region # 2 402) within 1 slot 420 on the time axis. Shows an example of what has been done. The control regions 401 and 402 may be set to a specific frequency resource 403 within the entire terminal bandwidth portion 410 on the frequency axis. The time axis may be set to one or a plurality of OFDM symbols, and this may be defined as a control region length (Control Resource Set Duration, 404). Referring to the illustrated example of FIG. 4 , control region #1 (401) is set to a control region length of 2 symbols, and control region #2 (402) is set to a control region length of 1 symbol.

The control region in the aforementioned 5G may be set by the base station to the terminal through higher layer signaling (eg, system information, master information block (MIB), radio resource control (RRC) signaling). Setting the control region to the terminal means providing information such as a control region identifier (Identity), a frequency location of the control region, and a symbol length of the control region. For example, it may include the following information.

In [Table 4], tci-StatesPDCCH (simply named TCI (Transmission Configuration Indication) state) configuration information is one or more SS (Synchronization signal)/PBCH (Physical Broadcast Channel) block index or CSI-RS (Channel State Information Reference Signal) index information.

5A illustrates an example of a structure of a downlink control channel in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 5A is a diagram showing an example of basic units of time and frequency resources constituting a downlink control channel that can be used in 5G. According to FIG. 5A, a basic unit of time and frequency resources constituting a control channel can be referred to as a REG (Resource Element Group, 503), and the REG 503 is 1 OFDM symbol 501 on the time axis and 1 PRB on the frequency axis. (Physical Resource Block, 502), that is, it can be defined as 12 subcarriers. The base station may configure a downlink control channel allocation unit by concatenating the REGs 503.

As shown in FIG. 5A, when a basic unit to which a downlink control channel is allocated in 5G is a Control Channel Element (CCE) 504, one CCE 504 may be composed of a plurality of REGs 503. Taking the REG 503 shown in FIG. 5A as an example, the REG 503 may consist of 12 REs, and if 1 CCE 504 consists of 6 REGs 503, 1 CCE 504 may consist of 72 REs. When a downlink control region is set, the corresponding region can be composed of a plurality of CCEs 504, and a specific downlink control channel is divided into one or a plurality of CCEs 504 according to an aggregation level (AL) in the control region. It can be mapped and transmitted. The CCEs 504 in the control area are identified by numbers, and at this time, the numbers of the CCEs 504 may be assigned according to a logical mapping method.

The basic unit of the downlink control channel, that is, the REG 503 shown in FIG. 5A, may include both REs to which DCI is mapped and a region to which the DMRS 505, which is a reference signal for decoding them, is mapped. As shown in FIG. 5A, three DMRSs 505 may be transmitted within one REG 503. The number of CCEs required to transmit the PDCCH can be 1, 2, 4, 8, or 16 according to the aggregation level (AL), and the different numbers of CCEs can be used for link adaptation of the downlink control channel. can be used to implement For example, when AL=L, one downlink control channel can be transmitted through L CCEs. A UE needs to detect a signal without knowing information about a downlink control channel. A search space representing a set of CCEs is defined for blind decoding. The search space is a set of downlink control channel candidates consisting of CCEs that the UE should attempt to decode on a given aggregation level, and various aggregations that make one group with 1, 2, 4, 8, and 16 CCEs Since there are levels, the terminal can have a plurality of search spaces. A search space set may be defined as a set of search spaces at all set aggregation levels.

The search space can be classified into a common search space and a UE-specific search space. A certain group of terminals or all terminals can search the common search space of the PDCCH in order to receive cell-common control information such as dynamic scheduling for system information or a paging message. For example, PDSCH scheduling allocation information for SIB transmission including cell operator information may be received by examining the common search space of the PDCCH. In the case of a common search space, since a certain group of terminals or all terminals must receive the PDCCH, it can be defined as a set of pre-promised CCEs. Scheduling assignment information for the UE-specific PDSCH or PUSCH may be received by examining the UE-specific search space of the PDCCH. The UE-specific search space may be defined UE-specifically as a function of the identity of the UE and various system parameters.

In 5G, a parameter for a search space for a PDCCH may be configured from a base station to a terminal through higher layer signaling (eg, SIB, MIB, RRC signaling). For example, the base station includes the number of PDCCH candidate groups at each aggregation level L, a monitoring period for the search space, a monitoring occasion in symbol units within a slot for the search space, a search space type (common search space or UE-specific search space), A combination of a DCI format and an RNTI to be monitored in the corresponding search space, a control region index to be monitored in the search space, and the like may be set to the terminal. For example, it may include the following information.

According to the setting information, the base station may set one or a plurality of search space sets for the terminal. According to some embodiments, the base station may set search space set 1 and search space set 2 to the terminal, set DCI format A scrambled with X-RNTI in search space set 1 to be monitored in a common search space, and search DCI format B scrambled with Y-RNTI in space set 2 can be configured to be monitored in a UE-specific search space.

According to the setting information, one or a plurality of search space sets may exist in a common search space or a terminal-specific search space. For example, search space set #1 and search space set #2 may be set as common search spaces, and search space set #3 and search space set #4 may be set as terminal-specific search spaces.

In the common search space, a combination of the following DCI format and RNTI can be monitored. Of course, it is not limited to the following examples.

- DCI format 0_0/1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

- DCI format 2_0 with CRC scrambled by SFI-RNTI

- DCI format 2_1 with CRC scrambled by INT-RNTI

- DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

- DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

In the UE-specific search space, a combination of the following DCI format and RNTI may be monitored. Of course, it is not limited to the following examples.

- DCI format 0_0/1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

- DCI format 1_0/1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

The specified RNTIs may follow the following definitions and uses.

C-RNTI (Cell RNTI): Use of UE-specific PDSCH scheduling

TC-RNTI (Temporary Cell RNTI): Use for UE-specific PDSCH scheduling

CS-RNTI (Configured Scheduling RNTI): Use of semi-statically configured UE-specific PDSCH scheduling

RA-RNTI (Random Access RNTI): PDSCH scheduling in random access phase

P-RNTI (Paging RNTI): PDSCH scheduling purpose through which paging is transmitted

SI-RNTI (System Information RNTI): PDSCH scheduling purpose for transmitting system information

INT-RNTI (Interruption RNTI): used to inform whether pucturing for PDSCH

TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control command for PUSCH

TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Use to indicate power control command for PUCCH

TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control command for SRS

The aforementioned specified DCI formats may follow the definition below.

In 5G, the search space of the aggregation level L in the control region p and the search space set s can be expressed as in [Equation 1] below.

값은 공통 탐색공간의 경우 0에 해당할 수 있다.

The value may correspond to 0 in the case of a common search space.

값은 단말-특정 탐색공간의 경우, 단말의 신원(C-RNTI 또는 기지국이 단말에게 설정해준 ID)과 시간 인덱스에 따라 변하는 값에 해당할 수 있다.

In the case of a UE-specific search space, the value may correspond to a value that changes according to the identity of the UE (C-RNTI or ID set for the UE by the base station) and the time index.

In 5G, as a plurality of search space sets can be set with different parameters (eg, parameters in [Table 5]), the set of search space sets monitored by the terminal at each point in time may be different. For example, if search space set #1 is set to an X-slot period and search space set #2 is set to a Y-slot period and X and Y are different, the terminal searches search space set #1 and search space set #1 in a specific slot. All space set #2 can be monitored, and one of search space set #1 and search space set #2 can be monitored in a specific slot.

[PDCCH: span]

The terminal may perform a terminal capability report for the case of having a plurality of PDCCH monitoring positions within a slot for each subcarrier interval, and in this case, the concept of span may be used. A span means consecutive symbols in which a terminal can monitor a PDCCH within a slot, and each PDCCH monitoring position is within one span. A span can be expressed as (X,Y), where x means the minimum number of symbols that must be separated between the first symbols of two consecutive spans, and Y is the number of consecutive symbols that can monitor the PDCCH within one span. says At this time, the UE can monitor the PDCCH in a section within Y symbols from the first symbol of Span within Span.

5B illustrates an example of a case in which a terminal may have a plurality of PDCCH monitoring positions within a slot in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 5B is a diagram illustrating a case where a terminal can have a plurality of PDCCH monitoring positions in a slot in a wireless communication system through Span. Span can be (X,Y) = (7,3), (4,3), (2,2), and in the three cases, each span is Span (511), Span (512), Span ( 513) is expressed. As an example, Span (511) represents the case where there are two spans in a slot that can be expressed as (7,4). The interval between the first symbols of two spans is expressed as X=7, PDCCH monitoring positions can exist within a total of Y=3 symbols from the first symbol of each span, and search spaces 1 and 2 within Y=3 symbols indicated the presence of each. As another example, Span (512) expresses the case where there are a total of three spans in a slot that can be expressed as (4,3), and the interval between the second and third spans is X' greater than X=4. =5 symbols away.

[PDCCH: UE Capability Report]

Slot positions in which the above-described common search space and the terminal-specific search space are located are indicated by the monitoringSymbolsWitninSlot parameter in Table 11-1, and the symbol position in the slot is indicated as a bitmap through the monitoringSymbolsWithinSlot parameter in Table 9. Meanwhile, a symbol position within a slot in which search space monitoring is possible by the terminal may be reported to the base station through the following UE capabilities.

- Terminal capability 1 (hereinafter referred to as FG 3-1). As shown in Table 9a below, when there is one MO monitoring occasion (MO) for the type 1 and type 3 common search space or the UE-specific search space in the slot, the corresponding MO location is the first in the slot, as shown in Table 9a below. When located within 3 symbols, it means the ability to monitor the corresponding MO. This UE capability is a mandatory capability that all UEs supporting NR must support, and whether or not this capability is supported is not explicitly reported to the base station.

dFeature group Components Field name in TS 38.331 [2] Basic DL control channel 1) One configured CORESET per BWP per cell in addition to CORESET0- CORESET resource allocation of 6RB bit-map and duration of 1 - 3 OFDM symbols for FR1
- For type 1 CSS without dedicated RRC configuration and for type 0, 0A, and 2 CSSs, CORESET resource allocation of 6RB bit-map and duration 1-3 OFDM symbols for FR2
- For type 1 CSS with dedicated RRC configuration and for type 3 CSS, UE specific SS, CORESET resource allocation of 6RB bit-map and duration 1-2 OFDM symbols for FR2
- REG-bundle sizes of 2/3 RBs or 6 RBs
- Interleaved and non-interleaved CCE-to-REG mapping
- Precoder-granularity of REG-bundle size
- PDCCH DMRS scrambling determination
- TCI state(s) for a CORESET configuration
2) CSS and UE-SS configurations for unicast PDCCH transmission per BWP per cell
- PDCCH aggregation levels 1, 2, 4, 8, 16
- UP to 3 search space sets in a slot for a scheduled SCell per BWP
This search space limit is before applying all dropping rules.
- For type 1 CSS with dedicated RRC configuration, type 3 CSS, and UE-SS, the monitoring occasion is within the first 3 OFDM symbols of a slot
- For type 1 CSS without dedicated RRC configuration and for type 0, 0A, and 2 CSS, the monitoring occasion can be any OFDM symbol(s) of a slot, with the monitoring occasions for any of Type 1- CSS without dedicated RRC configuration , or Types 0, 0A, or 2 CSS configurations within a single span of three consecutive OFDM symbols within a slot
3) Monitoring DCI formats 0_0, 1_0, 0_1, 1_1
4) Number of PDCCH blind decodes per slot with a given SCS follows Case 1-1 table
5) Processing one unicast DCI scheduling DL and one unicast DCI scheduling UL per slot per scheduled CC for FDD
6) Processing one unicast DCI scheduling DL and 2 unicast DCI scheduling UL per slot per scheduled CC for TDD
n/a

- Terminal capability 2 (hereafter referred to as FG 3-2). As shown in Table 11-2 below, when there is one MO monitoring occasion (MO) in a slot for a common search space or a UE-specific search space, regardless of the position of the start symbol of the corresponding MO, as shown in Table 11-2 below, It means the ability to monitor. This terminal capability can be selectively supported by the terminal (optional), and whether or not this capability is supported is explicitly reported to the base station.

- Terminal capability 3 (hereafter referred to as FGs 3-5, 3-5a, 3-5b). As shown in Table 11-3 below, the UE capability indicates a pattern of MOs that can be monitored by the UE when a plurality of monitoring occasions (MOs) for a common search space or a UE-specific search space exist in a slot. do. The above-described pattern consists of a starting inter-symbol interval X between different MOs and a maximum symbol length Y for one MO. The combination of (X,Y) supported by the terminal may be one or a plurality of {(2,2), (4,3), (7,3)}. This terminal capability can be selectively supported by the terminal (optional), and whether or not this capability is supported and the above-described (X,Y) combination are explicitly reported to the base station.

dFeature group Components Field name in TS 38.331 [2] -For type 1 CSS with dedicated RRC configuration, type 3 CSS, and UE-SS, monitoring occasion can be any OFDM symbol(s) of a slot for Case 2 For type 1 CSS with dedicated RRC configuration, type 3 CSS, and UE-SS, monitoring occasion can be any OFDM symbol(s) of a slot for Case 2 pdcch-MonitoringAnyOccasions {3-5. withoutDCI-Gap
3-5a. with DCI-Gap
} For type 1 CSS with dedicated RRC configuration, type 3 CSS, and UE-SS, monitoring occasion can be any OFDM symbol(s) of a slot for Case 2 with a DCI gap For type 1 CSS with dedicated RRC configuration, type 3 CSS and UE-SS, monitoring occasion can be any OFDM symbol(s) of a slot for Case 2, with minimum time separation (including the cross-slot boundary case) between two DL unicast DCIs, between two UL unicast DCIs, or between a DL and an UL unicast DCI in different monitoring occasions where at least one of them is not the monitoring occasions of FG-3-1, for a same UE as
- 2OFDM symbols for 15kHz
- 4 OFDM symbols for 30kHz
- 7OFDM symbols for 60kHz with NCP
- 11 OFDM symbols for 120kHz
Up to one unicast DL DCI and up to one unicast UL DCI in a monitoring occasion except for the monitoring occasions of FG 3-1.
In addition for TDD the minimum separation between the first two UL unicast DCIs within the first 3 OFDM symbols of a slot can be zero OFDM symbols. All PDCCH monitoring occasion can be any OFDM symbol(s) of a slot for Case 2 with a span gap PDCCH monitoring occasions of FG-3-1, plus additional PDCCH monitoring occasion(s) can be any OFDM symbol(s) of a slot for Case 2, and for any two PDCCH monitoring occasions belonging to different spans, where at least one of they are not the monitoring occasions of FG-3-1, in same or different search spaces, there is a minimum time separation of X OFDM symbols (including the cross-slot boundary case) between the start of two spans, where each span is of length up to Y consecutive OFDM symbols of a slot. Spans do not overlap. Every span is contained in a single slot. The same span pattern repeats in every slot. The separation between consecutive spans within and across slots may be unequal but the same (X, Y) limit must be satisfied by all spans. Every monitoring occasion is fully contained in one span. In order to determine a suitable span pattern, first a bitmap b(l), 0<=l<=13 is generated, where b(l)=1 if symbol l of any slot is part of a monitoring occasion, b(l )=0 otherwise. The first span in the span pattern begins at the smallest l for which b(l)=1. The next span in the span pattern begins at the smallest l not included in the previous span(s) for which b(l)=1. The span duration is max{maximum value of all CORESET durations, minimum value of Y in the UE reported candidate value} except possibly the last span in a slot which can be of shorter duration. A particular PDCCH monitoring configuration meets the UE capability limitation if the span arrangement satisfies the gap separation for at least one (X, Y) in the UE reported candidate value set in every slot, including cross slot boundary.For the set of monitoring occasions which are within the same span:
*j* Processing one unicast DCI scheduling DL and one unicast DCI scheduling Uper scheduled CC across this set of monitoring occasions for FDD
*j* Processing one unicast DCI scheduling DL and two unicast DCI scheduling Uper scheduled CC across this set of monitoring occasions for TDD
*j* Processing two unicast DCI scheduling DL and one unicast DCI scheduling Uper scheduled CC across this set of monitoring occasions for TDD
The number of different start symbol indices of spans for all PDCCH monitoring occasions per slot, including PDCCH monitoring occasions of FG-3-1, is no more than floor(14/X) (X is minimum among values reported by UE).
The number of different start symbol indices of PDCCH monitoring occasions per slot including PDCCH monitoring occasions of FG-3-1, is no more than 7.
The number of different start symbol indices of PDCCH monitoring occasions per half-slot including PDCCH monitoring occasions of FG-3-1 is no more than 4 in SCell.

The UE may report whether or not to support UE capability 2 and/or UE capability 3 and related parameters to the BS. The base station may perform time axis resource allocation for a common search space and a terminal-specific search space based on the reported terminal capabilities. When allocating the resource, the base station may prevent the terminal from locating the MO in a position where monitoring is impossible.

[PDCCH: BD/CCE limit]

When a plurality of search space sets are configured for a terminal, the following conditions may be considered in a method for determining a search space set to be monitored by a terminal.

If the UE has set the value of monitoringCapabilityConfig-r16, which is upper layer signaling, to r15monitoringcapability, the UE can monitor the number of PDCCH candidate groups that can be monitored and the total search space (here, the total search space is the number corresponding to the union area of a plurality of search space sets). The maximum value for the number of CCEs constituting the entire CCE set) is defined for each slot, and if the value of monitoringCapabilityConfig-r16 is set to r16monitoringcapability, the UE determines the number of PDCCH candidates that can be monitored and the total search space ( Here, the total search space means the entire set of CCEs corresponding to the union area of a plurality of search space sets). The maximum value for the number of CCEs constituting each span is defined.

[Condition 1: Limit the maximum number of PDCCH candidates]

[Table 10] , When defined based on Span, the following [Table 11] can be followed.

[Condition 2: Limit the maximum number of CCEs]

As described above, Cμ, the maximum number of CCEs constituting the entire search space (here, the entire search space means the entire set of CCEs corresponding to the union area of a plurality of search space sets) according to the setting value of higher layer signaling, is a subcarrier [Table 12] can be followed when defined on a slot basis in a cell set at an interval of 15·2μ kHz, and [Table 13] below can be followed when defined on a span basis.

For convenience of explanation, a situation in which both conditions 1 and 2 are satisfied at a specific point in time is defined as “condition A”. Accordingly, not satisfying condition A may mean not satisfying at least one of conditions 1 and 2 above.

[PDCCH: Overbooking]

Depending on the setting of search space sets of the base station, a case in which condition A is not satisfied may occur at a specific point in time. When condition A is not satisfied at a specific time point, the terminal may select and monitor only a part of search space sets configured to satisfy condition A at that time point, and the base station may transmit a PDCCH to the selected search space set.

As a method of selecting some search spaces from the set of all set search spaces, the following method may be followed.

If condition A for the PDCCH is not satisfied at a specific time point (slot), the UE (or the base station) selects a search space set whose search space type is set to a common search space among search space sets existing at that time point. - Priority can be given to a search space set set as a specific search space.

When all search space sets set as the common search space are selected (that is, when condition A is satisfied even after all search spaces set as the common search space are selected), the terminal (or the base station) terminal-specific search space Search space sets set to can be selected. In this case, when there are a plurality of search space sets set as the terminal-specific search space, a search space set having a lower search space set index may have a higher priority. In consideration of priority, UE-specific search space sets may be selected within a range satisfying condition A.

[QCL, TCI state]

In a wireless communication system, one or more different antenna ports (or one or more channels, signals, and combinations thereof may be substituted, but in the future description of the present disclosure, for convenience, different antenna ports are collectively referred to) They can be associated with each other by setting Quasi co-location (QCL) as shown in [Table 10] below. The TCI state is to notify the QCL relationship between a PDCCH (or PDCCH DMRS) and another RS or channel. A reference antenna port A (reference RS #A) and another target antenna port B (target RS #B) are QCL QCLed means that the terminal is allowed to apply some or all of the large-scale channel parameters estimated from the antenna port A to channel measurement from the antenna port B. QCL is 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by Doppler shift and Doppler spread, 3) RRM (radio resource management) affected by average gain, 4) spatial parameter It may be necessary to associate different parameters depending on circumstances such as affected beam management (BM). Accordingly, NR supports four types of QCL relationships as shown in [Table 14] below.

The spatial RX parameter includes various parameters such as Angle of arrival (AoA), Power Angular Spectrum (PAS) of AoA, Angle of departure (AoD), PAS of AoD, transmit/receive channel correlation, transmit/receive beamforming, and spatial channel correlation. Some or all of them may be generically named.

The QCL relationship can be set to the terminal through the RRC parameters TCI-State and QCL-Info as shown in [Table 15] below. Referring to [Table 15], the base station sets one or more TCI states to the UE and informs the UE of up to two QCL relationships (qcl-Type1, qcl-Type2) for the RS referring to the ID of the TCI state, that is, the target RS. can At this time, each QCL information (QCL-Info) included in each of the TCI states includes the serving cell index and BWP index of the reference RS indicated by the corresponding QCL information, the type and ID of the reference RS, and the QCL type as shown in [Table 14] above. includes

6 illustrates an example of a DRX operation in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 6 is a diagram for explaining DRX (Discontinuous Reception).

Discontinuous Reception (DRX) is an operation in which a terminal using a service discontinuously receives data in an RRC Connected state in which a radio link is established between a base station and a terminal. When DRX is applied, the terminal can turn on the receiver at a specific time point to monitor the control channel, and turn off the receiver when there is no data received for a certain period of time to reduce power consumption of the terminal. DRX operation can be controlled by the MAC layer device based on various parameters and timers.

Referring to FIG. 6, Active time 605 is the time when the UE wakes up every DRX cycle and monitors the PDCCH. Active time 605 can be defined as follows.

- drx-onDurationTimer or drx-InactivityTimer or drx-RetransmissionTimerDL or drx-RetransmissionTimerUL or ra-ContentionResolutionTimer is running; or

- a Scheduling Request is sent on PUCCH and is pending; or

- a PDCCH indicating a new transmission addressed to the C-RNTI of the MAC entity has not been received after successful reception of a Random Access Response for the Random Access Preamble not selected by the MAC entity among the contention-based Random Access Preamble

drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, ra-ContentionResolutionTimer, etc. are timers whose values are set by the base station. Have.

drx-onDurationTimer (615) is a parameter for setting the minimum time the UE is awake in the DRX cycle. The drx-InactivityTimer 620 is a parameter for setting an additional awake time when a PDCCH indicating a new uplink transmission or downlink transmission is received (630). drx-RetransmissionTimerDL is a parameter for setting the maximum awake time of a UE to receive a downlink retransmission in a downlink HARQ procedure. drx-RetransmissionTimerUL is a parameter for setting the maximum time during which the UE is awake to receive an uplink retransmission grant in an uplink HARQ procedure. drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, and drx-RetransmissionTimerUL may be set to, for example, time, the number of subframes, and the number of slots. ra-ContentionResolutionTimer is a parameter for monitoring PDCCH in a random access procedure.

InActive time 610 is a time set not to monitor PDCCH or/or not to receive PDCCH during DRX operation. (610) can be. If the terminal does not monitor the PDCCH during the active time 605, it can reduce power consumption by entering a sleep or inactive state.

The DRX cycle means a period in which the UE wakes up and monitors the PDCCH. That is, it means a time interval or an on-duration occurrence period until the UE monitors the next PDCCH after monitoring the PDCCH. There are two types of DRX cycle: short DRX cycle and long DRX cycle. Short DRX cycle can be applied as an option.

Long DRX cycle 625 is a long cycle among two DRX cycles set in the terminal. While operating in Long DRX, the terminal starts drx-onDurationTimer (615) again at the time when as much as Long DRX cycle (625) has elapsed from the start point (eg, start symbol) of drx-onDurationTimer (615). When operating with a Long DRX cycle (625), the terminal may start drx-onDurationTimer (615) in a slot after drx-SlotOffset in a subframe that satisfies the following [Equation 2]. Here, drx-SlotOffset means a delay before starting drx-onDurationTimer 615. drx-SlotOffset may be set to, for example, time, number of slots, and the like.

At this time, drx-LongCycleStartOffset may be used to define a Long DRX cycle (625) and drx-StartOffset to define a subframe from which the Long DRX cycle (625) starts. drx-LongCycleStartOffset may be set to, for example, time, number of subframes, number of slots, and the like.

[PDCCH: DCI related]

Next, downlink control information (DCI) in the 5G system will be described in detail.

Scheduling information for uplink data (or physical uplink shared channel (PUSCH)) or downlink data (or physical downlink shared channel (PDSCH)) in a 5G system is provided through DCI It is transmitted from the base station to the terminal. The UE may monitor the DCI format for fallback and the DCI format for non-fallback with respect to PUSCH or PDSCH. The contingency DCI format may be composed of a fixed field predefined between the base station and the terminal, and the non-preparation DCI format may include a configurable field.

DCI may be transmitted through a physical downlink control channel (PDCCH) through channel coding and modulation processes. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC may be scrambled with a Radio Network Temporary Identifier (RNTI) corresponding to the identity of the terminal. Different RNTIs may be used according to the purpose of the DCI message, eg, UE-specific data transmission, power control command, or random access response. That is, the RNTI is not transmitted explicitly but is included in the CRC calculation process and transmitted. Upon receiving the DCI message transmitted on the PDCCH, the UE checks the CRC using the allocated RNTI, and if the CRC check result is correct, the UE can know that the corresponding message has been transmitted to the UE.

For example, DCI scheduling a PDSCH for system information (SI) may be scrambled with SI-RNTI. A DCI scheduling a PDSCH for a Random Access Response (RAR) message may be scrambled with RA-RNTI. A DCI scheduling a PDSCH for a paging message may be scrambled with a P-RNTI. DCI notifying SFI (Slot Format Indicator) may be scrambled with SFI-RNTI. DCI notifying TPC (Transmit Power Control) can be scrambled with TPC-RNTI. DCI scheduling UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, and in this case, CRC can be scrambled with C-RNTI. DCI format 0_0 in which CRC is scrambled with C-RNTI may include, for example, the following information.

DCI format 0_1 can be used as a non-backup DCI for scheduling PUSCH, and in this case, CRC can be scrambled with C-RNTI. DCI format 0_1 in which CRC is scrambled with C-RNTI may include, for example, the following information.

DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, and in this case, CRC can be scrambled with C-RNTI. DCI format 1_0 in which CRC is scrambled with C-RNTI may include, for example, the following information.

DCI format 1_1 can be used as a non-backup DCI for scheduling PDSCH, and in this case, CRC can be scrambled with C-RNTI. DCI format 1_1 in which CRC is scrambled with C-RNTI may include, for example, the following information.

7 illustrates an example of base station beam allocation according to TCI state setting in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 7 is a diagram illustrating an example of base station beam allocation according to TCI state setting. Referring to FIG. 7 , the base station may transmit information on different N beams to the terminal through different N TCI states. For example, as shown in FIG. 7, when N = 3, the base station has qcl-Type2 parameters included in three TCI states (700, 705, and 710) associated with CSI-RS or SSB corresponding to different beams, and QCL type D By setting to , it can be notified that the antenna ports referring to the different TCI states 700, 705, or 710 are associated with different spatial Rx parameters, that is, different beams.

[Table 20] to [Table 24] show effective TCI state settings according to the type of target antenna port.

[Table 20] shows valid TCI state settings when the target antenna port is CSI-RS for tracking (TRS). The TRS means an NZP CSI-RS in which a repetition parameter is not set and trs-Info is set to true among CSI-RSs. In the case of setting No. 3 in [Table 20], it can be used for aperiodic TRS.

[Table 21] shows effective TCI state settings when the target antenna port is CSI-RS for CSI. The CSI-RS for CSI refers to an NZP CSI-RS in which a parameter indicating repetition (eg, a repetition parameter) is not set and trs-Info is not set to true among CSI-RSs.

[Table 22] indicates effective TCI state settings when the target antenna port is CSI-RS for beam management (BM, meaning the same as CSI-RS for L1 RSRP reporting). The CSI-RS for BM means an NZP CSI-RS in which the repetition parameter is set among CSI-RSs and has a value of On or Off, and trs-Info is not set to true.

[Table 23] shows effective TCI state settings when the target antenna port is PDCCH DMRS.

[Table 24] shows valid TCI state settings when the target antenna port is PDSCH DMRS.

In the representative QCL setting method according to [Table 20] to [Table 24], the target antenna port and reference antenna port for each step are set to "SSB" -> "TRS" -> "CSI-RS for CSI, or CSI-RS for BM, or PDCCH DMRS, or PDSCH DMRS" is set and operated. Through this, it is possible to help the reception operation of the terminal by linking the statistical characteristics measurable from the SSB and TRS to each antenna port.

[PDCCH: related to TCI state]

Specifically, the TCI state combination applicable to the PDCCH DMRS antenna port is shown in [Table 25]. In [Table 25], the 4th row is a combination assumed by the terminal before RRC configuration, and configuration after RRC is impossible.

8 illustrates an example of TCI state allocation for a PDCCH in a wireless communication system according to various embodiments of the present disclosure. Specifically, NR supports a hierarchical signaling method as shown in FIG. 8 for dynamic allocation of PDCCH beams. Referring to FIG. 8, the base station can set N TCI states (805, 810, ??, 820) to the terminal through RRC signaling 800, and some of them can be set as TCI states for CORESET ( 825). Thereafter, the base station may instruct the terminal one of TCI states (830, 835, 840) for CORESET through MAC CE signaling (845). Thereafter, the UE receives the PDCCH based on beam information included in the TCI state indicated by the MAC CE signaling.

9 illustrates an example of a TCI indicating MAC CE signaling structure for PDCCH DMRS in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 9 is a diagram illustrating a TCI indication MAC CE signaling structure for the PDCCH DMRS. Referring to FIG. 9, the TCI indication MAC CE signaling for the PDCCH DMRS consists of 2 bytes (16 bits), 5-bit serving cell ID 915, 4-bit CORESET ID 920, and 7-bit TCI state ID 925.

10 illustrates an example of beam configuration of a control resource set and a search space in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 10 is a diagram illustrating an example of beam configuration of a control resource set (CORESET) and a search space according to the above description. Referring to FIG. 10, the base station may indicate one of the TCI state lists included in the CORESET 1000 configuration through MAC CE signaling (1005). After that, until another TCI state is indicated to the corresponding CORESET through another MAC CE signaling, the UE uses the same QCL information (beam #1, 1005) in one or more search spaces (1010, 1015, 1020) connected to the CORESET. is considered to apply. The PDCCH beam allocation method described above makes it difficult to indicate a beam change faster than the MAC CE signaling delay, and also has the disadvantage of collectively applying the same beam for each CORESET regardless of search space characteristics, which makes flexible PDCCH beam operation difficult. there is In the following embodiments of the present invention, more flexible PDCCH beam configuration and operation methods are provided. Hereinafter, in describing the embodiments of the present invention, several distinct examples are provided for convenience of explanation, but they are not mutually exclusive and can be applied by appropriately combining with each other depending on the situation.

The base station may set one or a plurality of TCI states for a specific control region to the terminal, and may activate one of the set TCI states through a MAC CE activation command. For example, {TCI state#0, TCI state#1, TCI state#2} are set as TCI states in control region #1, and the base station sets the TCI state for control region #1 through MAC CE. A command enabling to assume #0 may be transmitted to the terminal. The terminal can correctly receive the DMRS of the corresponding control region based on the QCL information in the activated TCI state based on the activation command for the TCI state received through the MAC CE.

Regarding the control area (control area #0) whose index is set to 0, if the terminal does not receive the MAC CE activation command for the TCI state of control area #0, the terminal responds to the DMRS transmitted from the control area #0 It may be assumed that the SS/PBCH block identified in the initial access process or in the non-contention based random access process not triggered by the PDCCH command is QCL.

Regarding the control area (control area #X) where the index is set to a value other than 0, if the terminal does not set the TCI state for the control area #X or activates one of them even though one or more TCI states are set If the MAC CE activation command is not received, the terminal may assume that the SS/PBCH block identified in the initial access process is QCL with respect to the DMRS transmitted in the control region #X.

[PDCCH: related to QCL prioritization rule]

In the following, the QCL priority determination operation for the PDCCH will be described in detail.

The UE operates with carrier aggregation within a single cell or band, and a plurality of control resource sets existing within an activated bandwidth portion within a single or multiple cells have the same or different QCL-TypeD characteristics in a specific PDCCH monitoring interval and In case of overlapping, the terminal may select a specific control resource set according to the QCL priority determination operation and monitor control resource sets having the same QCL-TypeD characteristics as the corresponding control resource set. That is, when a plurality of control resource sets overlap in time, only one QCL-TypeD characteristic can be received. In this case, the criteria for determining the QCL priority may be as follows.

- Criterion 1. A control resource set connected to the common search section of the lowest index within a cell corresponding to the lowest index among cells including a common search section.

- Criterion 2. A control resource set associated with a UE-specific search interval having the lowest index within a cell corresponding to the lowest index among cells including a UE-specific search interval.

As described above, each of the above criteria applies the next criterion when the criterion is not satisfied. For example, when control resource sets overlap in time in a specific PDCCH monitoring period, if all control resource sets are not connected to a common search period but connected to a terminal-specific search period, that is, if criterion 1 is not satisfied, the terminal may omit the application of criterion 1 and apply criterion 2.

When selecting a control resource set based on the above criteria, the terminal may additionally consider the following two items for QCL information set in the control resource set. First, if control resource set 1 has CSI-RS 1 as a reference signal having a QCL-TypeD relationship, and this CSI-RS 1 has SSB 1 as a reference signal having a QCL-TypeD relationship, another If the reference signal with which control resource set 2 has a QCL-TypeD relationship is SSB 1, the UE may consider these two control resource sets 1 and 2 to have different QCL-TypeD characteristics. Second, if control resource set 1 has CSI-RS 1 set in cell 1 as a reference signal having a QCL-TypeD relationship, and this CSI-RS 1 has a QCL-TypeD relationship, the reference signal is SSB 1, control resource set 2 has CSI-RS 2 configured in cell 2 as a reference signal having a QCL-TypeD relationship, and this CSI-RS 2 has the same reference signal having a QCL-TypeD relationship. In the case of SSB 1, the UE may consider the two control resource sets to have the same QCL-TypeD characteristics.

11 illustrates an example of a method in which a base station and a terminal transmit and receive data in consideration of a downlink data channel and a rate matching resource in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 11 is a diagram for explaining a method for transmitting and receiving data by a base station and a terminal in consideration of a downlink data channel and a rate matching resource.

11 shows a downlink data channel (PDSCH) 1101 and a rate matching resource 1102. The base station may configure one or multiple rate matching resources 1102 to the terminal through higher layer signaling (eg, RRC signaling). The rate matching resource 1102 setting information may include time axis resource allocation information 1103 , frequency axis resource allocation information 1104 , and period information 1105 . In the following, the bitmap corresponding to the frequency-axis resource allocation information 1104 corresponds to the "first bitmap", the bitmap corresponding to the time-axis resource allocation information 1103 corresponds to the "second bitmap", and the period information 1105 The bitmap to be called is named "third bitmap". When all or part of the time and frequency resources of the scheduled data channel 1101 overlap with the configured rate matching resource 602, the base station rate-matches the data channel 1101 in the rate matching resource 1102 portion and transmits the , the terminal may perform reception and decoding after assuming that the data channel 1101 is rate-matched in the rate matching resource 1102 portion.

The base station may dynamically notify the terminal through DCI whether to rate match the data channel in the set rate matching resource part through additional configuration (corresponding to the "rate matching indicator" in the aforementioned DCI format) . Specifically, the base station may select some of the configured rate matching resources and group them into rate matching resource groups, and informs the terminal of whether rate matching of the data channel for each rate matching resource group is performed using a DCI using a bitmap method. can instruct For example, when four rate matching resources, RMR#1, RMR#2, RMR#3, and RMR#4 are set, the base station sets RMG#1 = {RMR#1, RMR#2}, RMG# as a rate matching group 2 = {RMR#3, RMR#4} can be set, and using 2 bits in the DCI field, rate matching in RMG#1 and RMG#2 can be indicated to the terminal using a bitmap. For example, "1" may be indicated when rate matching is to be performed, and "0" may be indicated when rate matching is not to be performed.

In 5G, granularity of "RB symbol level" and "RE level" is supported as a method of configuring the above-described rate matching resources in the UE. More specifically, the following setting method may be followed.

[RB Symbol Level]

The terminal may receive up to four RateMatchPatterns set for each bandwidth part by higher layer signaling, and one RateMatchPattern may include the following contents.

One. As a reserved resource in the bandwidth part, a resource in which time and frequency resource regions of the corresponding reserved resource are set in a combination of an RB level bitmap and a symbol level bitmap on the frequency axis may be included. The reserve resource may span one or two slots. A time domain pattern (periodicityAndPattern) in which time and frequency domains composed of each RB level and symbol level bitmap pair are repeated may be additionally set.

2. Time and frequency domain resource areas set as control resource sets within the bandwidth part and resource areas corresponding to time domain patterns set as search space settings in which the corresponding resource areas are repeated may be included.

[RE level]

The terminal may receive the following contents through higher layer signaling.

One. LTE CRS (Cell-specific Reference Signal or Common Reference Signal) configuration information (lte-CRS-ToMatchAround) for the RE corresponding to the pattern, the number of LTE CRS ports (nrofCRS-Ports) and LTE-CRS-vshift(s) values (v-shift), LTE carrier center subcarrier location information (carrierFreqDL) from the reference frequency point (eg, reference point A), LTE carrier bandwidth size (carrierBandwidthDL) information, MBSFN (Multicast-broadcast single -frequency network) and the like corresponding to subframe configuration information (mbsfn-SubframeConfigList). The terminal may determine the position of the CRS in the NR slot corresponding to the LTE subframe based on the above information.

2. It may include configuration information about a resource set corresponding to one or a plurality of ZP (Zero Power) CSI-RS in the bandwidth part.

[Related to LTE CRS rate match]

Next, the rate match process for the above-described LTE CRS will be described in detail. For the coexistence of Long Term Evolution (LTE) and New RAT (NR) (LTE-NR Coexistence), NR provides a function for setting a cell specific reference signal (CRS) pattern of LTE to the NR terminal. More specifically, the CRS pattern may be provided by RRC signaling including at least one parameter in a ServingCellConfig Information Element (IE) or a ServingCellConfigCommon IE. Examples of the parameters may include lte-CRS-ToMatchAround, lte-CRS-PatternList1-r16, lte-CRS-PatternList2-r16, crs-RateMatch-PerCORESETPoolIndex-r16, and the like.

The Rel-15 NR provides a function of setting one CRS pattern per serving cell through the lte-CRS-ToMatchAround parameter. In Rel-16 NR, the above function has been extended to enable setting of a plurality of CRS patterns per serving cell. More specifically, one CRS pattern can be set per one LTE carrier in a Single-transmission and reception point (TRP) setting terminal, and two CRS patterns per one LTE carrier in a Multi-TRP setting terminal could be set. For example, up to three CRS patterns per serving cell can be set in a single-TRP configuration terminal through the lte-CRS-PatternList1-r16 parameter. For another example, a CRS may be configured for each TRP in a multi-TRP configuration terminal. That is, the CRS pattern for TRP1 may be set through the lte-CRS-PatternList1-r16 parameter, and the CRS pattern for TRP2 may be set through the lte-CRS-PatternList2-r16 parameter. On the other hand, when two TRPs are set as above, crs-RateMatch-PerCORESETPoolIndex determines whether both the CRS patterns of TRP1 and TRP2 are applied to a specific PDSCH (Physical Downlink Shared Channel) or whether only the CRS pattern for one TRP is applied. It is determined through the -r16 parameter. If the crs-RateMatch-PerCORESETPoolIndex-r16 parameter is set to enabled, only the CRS pattern of one TRP is applied, and in other cases, both CRS patterns of the two TRPs are applied.

[Table 26] shows the ServingCellConfig IE including the CRS pattern, and [Table 27] shows the RateMatchPatternLTE-CRS IE including at least one parameter for the CRS pattern.

12 illustrates an example of a method for selecting a receivable control resource set in consideration of priority when a terminal receives a downlink control channel in a wireless communication system according to various embodiments of the present disclosure.

12 is a diagram for explaining a method for selecting a receivable control resource set in consideration of priority when a terminal receives a downlink control channel in a wireless communication system according to an embodiment of the present disclosure. For example, a UE may be configured to receive a plurality of control resource sets overlapping in time in a specific PDCCH monitoring period 1210, and these plurality of control resource sets are a common search space or a UE-specific search space for a plurality of cells. may be connected with Within the corresponding PDCCH monitoring period, within the first bandwidth portion 1200 of the first cell, the first control resource set 1215 connected to the first common discovery period may exist, and the first bandwidth portion of the second cell (1205 ), the first control resource set 1220 connected to the first common search period and the second control resource set 1225 connected to the second terminal-specific search period may exist. The control resource sets 1215 and 1220 have a relationship of CSI-RS resource #1 and QCL-TypeD set within the bandwidth part #1 of cell #1, and the control resource set 1225 is the bandwidth #1 of cell #2. It may have a relationship between CSI-RS resource No. 1 set in the part and QCL-TypeD. Therefore, if criterion 1 is applied to the corresponding PDCCH monitoring period 1210, all other control resource sets having QCL-TypeD reference signals such as the first control resource set 1215 can be received. Therefore, the terminal can receive the control resource sets 1215 and 1220 in the corresponding PDCCH monitoring period 1210. As another example, a UE may be configured to receive a plurality of control resource sets overlapping in time in a specific PDCCH monitoring period 1240, and the plurality of control resource sets may be configured to receive a common search space or a UE-specific search space for a plurality of cells. It may be related to the search space. Within the corresponding PDCCH monitoring interval, within the first bandwidth portion 1230 of cell #1, the first control resource set 1245 connected to the UE 1 specific search interval and the second control resource set connected to the UE 2 specific search interval 1250 may exist, and within the first bandwidth part 1235 of the second cell, the first control resource set 1255 connected to the first terminal-specific search period and the second control resource connected to the third terminal-specific search period A set 1260 may exist. Control resource sets 1245 and 1250 have a relationship of CSI-RS resource #1 and QCL-TypeD set within bandwidth #1 of cell #1, and control resource set 1255 is bandwidth #1 of cell #2 It has a QCL-TypeD relationship with the first CSI-RS resource set in the second cell, and the control resource set 1260 may have a QCL-TypeD relationship with the second CSI-RS resource set in the first bandwidth portion of the second cell. there is. However, when criterion 1 is applied to the corresponding PDCCH monitoring period 1240, since there is no common search period, criterion 2, which is the next criterion, can be applied. If criterion 2 is applied to the corresponding PDCCH monitoring period 1240, all other control resource sets having the same QCL-TypeD reference signal as the control resource set 1245 can be received. Therefore, the terminal can receive control resource sets 1245 and 1250 in the corresponding PDCCH monitoring period 1240.

[Related to Rate matching/Puncturing]

In the following, a rate matching operation and a puncturing operation will be described in detail.

When the time and frequency resource A to transmit a certain symbol sequence A overlaps with the random time and frequency resource B, rate matching or puncturing is performed by transmission/reception of channel A considering resource C in the area where resource A and resource B overlap motion can be considered. A specific operation may follow the following.

[Rate Matching Operation]

- The base station may map and transmit channel A only for the remaining resource regions excluding resource C corresponding to an overlapping region with resource B among all resources A to transmit symbol sequence A to the terminal. For example, symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol 4}, resource A is {resource #1, resource #2, resource #3, resource #4}, resource If B is {resource #3, resource #5}, the base station excluding {resource #3} corresponding to resource C among resource A is a symbol sequence for the remaining resources {resource #1, resource #2, resource #4} A can be sequentially mapped and sent. As a result, the base station may map symbol sequences {symbol #1, symbol #2, and symbol #3} to {resource #1, resource #2, and resource #4} and transmit them.

The terminal can determine resource A and resource B from scheduling information on symbol sequence A from the base station, and through this, it can determine resource C, which is an area where resource A and resource B overlap. The UE may receive the symbol sequence A assuming that the symbol sequence A is mapped and transmitted in the remaining regions excluding resource C from among all resources A. For example, symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol 4}, resource A is {resource #1, resource #2, resource #3, resource #4}, resource If B is {resource #3, resource #5}, the terminal excluding {resource #3} corresponding to resource C among resource A is a symbol sequence for the remaining resources {resource #1, resource #2, resource #4} It can be received assuming that A is sequentially mapped. As a result, the terminal assumes that the symbol sequences {symbol #1, symbol #2, and symbol #3} are mapped to {resource #1, resource #2, and resource #4}, respectively, and performs a series of reception operations thereafter. can

[Puncture operation]

The base station maps the symbol sequence A to the entire resource A when there is a resource C corresponding to a region overlapping with the resource B among all resources A to transmit the symbol sequence A to the terminal, but transmits in the resource region corresponding to the resource C Transmission may be performed only for the remaining resource regions excluding resource C from among resource A without performing the transmission. For example, symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol 4}, resource A is {resource #1, resource #2, resource #3, resource #4}, resource If B is {resource #3, resource #5}, the base station converts the symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} to resource A {resource #1, resource #2, resource # 3, resource #4}, and symbol sequences corresponding to {resource #1, resource #2, resource #4}, which are the remaining resources excluding {resource #3} corresponding to resource C among resource A { Only symbol #1, symbol #2, and symbol #4} may be transmitted, and {symbol #3} mapped to {resource #3} corresponding to resource C may not be transmitted. As a result, the base station may map symbol sequences {symbol #1, symbol #2, and symbol #4} to {resource #1, resource #2, and resource #4} and transmit them.

The terminal can determine resource A and resource B from scheduling information on symbol sequence A from the base station, and through this, it can determine resource C, which is an area where resource A and resource B overlap. The terminal may receive the symbol sequence A assuming that the symbol sequence A is mapped to the entire resource A and transmitted only in the remaining regions excluding resource C among the resource regions A. For example, symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol 4}, resource A is {resource #1, resource #2, resource #3, resource #4}, resource If B is {resource #3, resource #5}, the terminal determines that the symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} is resource A {resource #1, resource #2, resource # 3 and resource #4}, but it can be assumed that {symbol #3} mapped to {resource #3} corresponding to resource C is not transmitted, and {resource #3 corresponding to resource C among resource A }, it can be received assuming that the symbol sequence {symbol #1, symbol #2, symbol #4} corresponding to the remaining resources {resource #1, resource #2, resource #4} is mapped and transmitted. As a result, the terminal assumes that the symbol sequence {symbol #1, symbol #2, symbol #4} is mapped to {resource #1, resource #2, resource #4} and transmitted, and performs a series of subsequent reception operations. can

In the following, a method for setting rate matching resources for the purpose of rate matching in the 5G communication system will be described. Rate matching means that the size of the signal is adjusted in consideration of the amount of resources capable of transmitting the signal. For example, rate matching of a data channel may mean that the size of data is adjusted accordingly without mapping and transmitting the data channel for a specific time and frequency resource domain.

13 illustrates an example of frequency axis resource allocation of a PDSCH in a wireless communication system according to various embodiments of the present disclosure.

[PDSCH: related to frequency resource allocation]

13 is a diagram illustrating an example of frequency axis resource allocation of a physical downlink shared channel (PDSCH) in a wireless communication system according to an embodiment of the present disclosure.

FIG. 13 is a diagram illustrating three frequency axis resource allocation methods of type 0 (1300), type 1 (1305), and dynamic switch (1310) that can be set through an upper layer in an NR wireless communication system.

Referring to FIG. 13, if the terminal is configured to use only resource type 0 through higher layer signaling (1300), some downlink control information (DCI) for allocating a PDSCH to the terminal consists of NRBG bits contains a bitmap that is Conditions for this will be described later. At this time, NRBG means the number of RBGs (resource block groups) determined as shown in [Table 28] according to the BWP size allocated by the BWP indicator and the upper layer parameter rbg-Size. Data is transmitted to the RBG indicated by 1.

개의 비트들로 구성되는 주파수 축 자원 할당 정보를 포함한다. 이를 위한 조건은 차후 다시 설명된다. 기지국은 이를 통하여 starting VRB(1320)와 이로부터 연속적으로 할당되는 주파수 축 자원의 길이(1325)를 설정할 수 있다.If the terminal is configured to use only resource type 1 through higher layer signaling (1305), some DCIs allocating the PDSCH to the terminal

and frequency-axis resource allocation information consisting of N bits. Conditions for this will be described later. Through this, the base station can set the starting VRB 1320 and the length 1325 of frequency axis resources continuously allocated therefrom.

If the terminal is configured to use both resource type 0 and resource type 1 through higher layer signaling (1310), some DCIs allocating a PDSCH to the terminal include payload 1315 and resource type 1 for setting resource type 0 Includes frequency axis resource allocation information consisting of bits of a large value (1335) among payloads (1320, 1325) for setting . Conditions for this will be described later. At this time, one bit may be added to the first part (MSB) of the frequency axis resource allocation information in the DCI, and if the corresponding bit has a value of '0', it is indicated that resource type 0 is used, and if the value is '1', resource It may be indicated that type 1 is used.

[PDSCH/PUSCH: related to time resource allocation]

Hereinafter, a time domain resource allocation method for a data channel in a next-generation mobile communication system (5G or NR system) will be described.

The base station provides a table for time domain resource allocation information for a downlink shared channel (PDSCH) and a physical uplink shared channel (PUSCH) to the terminal, and higher layer signaling (eg, For example, RRC signaling). For PDSCH, a table consisting of maxNrofDL-Allocations = 16 entries can be set, and for PUSCH, a table consisting of maxNrofUL-Allocations = 16 entries can be set. In one embodiment, the time domain resource allocation information includes PDCCH-to-PDSCH slot timing (corresponding to a time interval in units of slots between a time when a PDCCH is received and a time when a PDSCH scheduled by the received PDCCH is transmitted, denoted as K0). ), PDCCH-to-PUSCH slot timing (corresponding to the time interval in units of slots between the time when the PDCCH is received and the time when the PUSCH scheduled by the received PDCCH is transmitted, denoted as K2), the PDSCH or PUSCH within the slot Information about the position and length of the scheduled start symbol, mapping type of PDSCH or PUSCH, etc. may be included.

For example, information such as [Table 29] or [Table 30] below may be transmitted from the base station to the terminal.

The base station may notify the terminal of one of the above-described table entries for time domain resource allocation information through L1 signaling (eg, DCI) (eg, to be indicated by the 'time domain resource allocation' field in DCI). can). The terminal may obtain time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

14 illustrates an example of time axis resource allocation in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 14 is a diagram illustrating an example of time axis resource allocation of a PDSCH in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 14, a base station uses subcarrier spacing (SCS) (μPDSCH, μPDCCH), scheduling offset of a data channel and a control channel configured using an upper layer. The time axis position of the PDSCH resource may be indicated according to the (K0) value and the OFDM symbol start position 1400 and length 1405 within one slot dynamically indicated through DCI.

15 illustrates an example of time axis resource allocation according to subcarrier intervals of a data channel and a control channel in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 15 is a diagram illustrating an example of time domain resource allocation according to subcarrier intervals of a data channel and a control channel in a wireless communication system according to an embodiment of the present disclosure.

μPDCCH), 데이터와 제어를 위한 슬롯 번호(slot number)가 다르므로, 기지국 및 단말은 PDCCH의 서브캐리어 간격을 기준으로 하여, 미리 정해진 슬롯 오프셋(slot offset) K0에 맞추어 스케줄링 오프셋(scheduling offset)을 생성할 수 있다.Referring to FIG. 15, when the subcarrier intervals of the data channel and the control channel are the same (1500, μPDSCH = μPDCCH), since the slot numbers for data and control are the same, the base station and the terminal have a predetermined slot offset ( According to the slot offset K0, a scheduling offset may be generated. On the other hand, when the subcarrier intervals of the data channel and the control channel are different (1505, μPDSCH

μPDCCH), since the slot numbers for data and control are different, the base station and the terminal set a scheduling offset according to a predetermined slot offset K0 based on the subcarrier interval of the PDCCH can create

[PDSCH: Processing Time]

Next, PDSCH processing procedure time will be described. When the base station schedules the terminal to transmit the PDSCH using DCI format 1_0, 1_1, or 1_2, the terminal uses the DCI-instructed transmission method (modulation and coding instruction index (MCS), demodulation reference signal related information, time and PDSCH processing time for receiving PDSCH by applying frequency resource allocation information, etc.) may be required. In NR, the PDSCH processing time was defined in consideration of this. The PDSCH processing time of the UE may follow [Equation 3] below.

In T _proc,1 described above with Equation 3, each variable may have the following meaning.

- N ₁ : The number of symbols determined according to UE processing capability 1 or 2 and numerology μ according to the capabilities of the UE. If it is reported as UE processing capability 1 according to the UE's capability report, it has the value of [Table 31], and it is reported as UE processing capability 2, and it is set through higher layer signaling that UE processing capability 2 can be used [Table 32] can have a value of The numerology μ may correspond to the minimum value among μ _PDCCH , μ _PDSCH , and μ _UL to maximize the T _proc,1 , and μ _PDCCH , μ _PDSCH , and μ _UL are the numerology and schedule of the PDCCH for which the PDSCH is scheduled, respectively. It may mean the numerology of the received PDSCH and the numerology of the uplink channel through which the HARQ-ACK will be transmitted.

[Table 31] relates to PDSCH processing time in case of PDSCH processing capability 1.

[Table 32] relates to PDSCH processing time in case of PDSCH processing capability 2.

- K: 64

- T _ext : When the UE uses the shared spectrum channel access method, the UE may calculate T _ext and apply it to the PDSCH processing time. Otherwise, T _ext is assumed to be zero.

- If l1 representing the PDSCH DMRS location value is 12, N1,0 in [Table 22] has a value of 14, otherwise it has a value of 13.

- For PDSCH mapping type A, the last symbol of the PDSCH is the ith symbol in the slot in which the PDSCH is transmitted, and if i < 7, d _1,1 is 7-i, otherwise d _1,1 is 0.

-d ₂ : When a PUCCH with a high priority index and a PUCCH or PUSCH with a low priority index overlap in time, d ₂ of the PUCCH with a high priority index may be set to a value reported from the UE. Otherwise, d ₂ is 0.

- When PDSCH mapping type B is used for UE processing capability 1, the value of d1,1 is determined according to the number of symbols L, which is the number of symbols of the scheduled PDSCH, and the number of symbols d overlapped between the PDCCH scheduling the PDSCH and the scheduled PDSCH as follows can

- If L ≥ 7, then d _1,1 = 0.

- if L ≥ 4 and L ≤ 6, then d _1,1 = 7 - L.

- if L = 3, then d _1,1 = min (d, 1).

- If L = 2, then d _1,1 = 3 + d.

- When PDSCH mapping type B is used for UE processing capability 2, the value of d _1,1 is the number of symbols L of the scheduled PDSCH and the number of overlapping symbols between the PDCCH scheduling the PDSCH and the scheduled PDSCH as follows. Depending on d can be determined

- If L ≥ 7, then d _1,1 = 0.

- if L ≥ 4 and L ≤ 6, then d _1,1 = 7 - L.

- if L = 2,

- If the scheduling PDCCH exists in a CORESET consisting of 3 symbols, and the CORESET and the scheduled PDSCH have the same start symbol, d _1,1 = 3.

- otherwise, d _1,1 = d.

- In the case of a UE supporting capability 2 within a given serving cell, PDSCH processing time according to UE processing capability 2 can be applied when the UE sets processingType2Enabled, which is higher layer signaling, to enable for the corresponding cell.

If the position of the first uplink transmission symbol of the PUCCH including the HARQ-ACK information (K ₁ defined as the transmission time of the HARQ-ACK, the PUCCH resource used for HARQ-ACK transmission, and the timing advance effect may be considered) If it does not start earlier than the first uplink transmission symbol that appears after a time of T _proc,1 from the last symbol of the PDSCH, the UE must transmit a valid HARQ-ACK message. That is, the UE must transmit the PUCCH including the HARQ-ACK only when the PDSCH processing time is sufficient. Otherwise, the terminal cannot provide valid HARQ-ACK information corresponding to the scheduled PDSCH to the base station. The above T _proc,1 can be used for both general and extended CP cases. In the case of a PDSCH composed of two PDSCH transmission positions within one slot, d _1,1 is calculated based on the first PDSCH transmission position within the corresponding slot.

[PDSCH: Receive preparation time for cross-carrier scheduling]

In the case of cross-carrier scheduling in which μ _PDCCH , which is the numerology through which PDCCH to be scheduled next is transmitted, and μ _PDSCH , which is the numerology through which PDSCH scheduled through the corresponding PDCCH is transmitted, are different from each other, the UE defined for the time interval between the PDCCH and the PDSCH The PDSCH reception preparation time of N _pdsch will be described.

If μ _PDCCH < μ _PDSCH , the scheduled PDSCH cannot be transmitted before the first symbol of the slot following the Npdsch symbol from the last symbol of the PDCCH that scheduled the corresponding PDSCH. A transmission symbol of the corresponding PDSCH may include a DM-RS.

If μ _PDCCH > μ _PDSCH , the scheduled PDSCH may be transmitted from N _pdsch symbols after the last symbol of the PDCCH that scheduled the corresponding PDSCH. A transmission symbol of the corresponding PDSCH may include a DM-RS.

[Table 33] relates to N _pdsch according to the scheduled PDCCH subcarrier interval.

[PDSCH: TCI state activation MAC-CE]

Next, a beam configuration method for the PDSCH will be described.

16 illustrates an example of beam configuration and activation of a PDSCH in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 16 illustrates a process for setting and activating a PDSCH beam. A list of TCI states for the PDSCH may be indicated through an upper layer list such as RRC (1600). The list of the TCI states may be indicated, for example, by tci-StatesToAddModList and/or tci-StatesToReleaseList in the PDSCH-Config IE for each BWP. Next, some of the list of TCI states can be activated through MAC-CE (1620). The maximum number of activated TCI states may be determined according to capabilities reported by the UE. 1650 shows an example of a MAC-CE structure for PDSCH TCI state activation/deactivation.

The meaning of each field in the MAC CE and values that can be set for each field are as follows.

[SRS related]

Next, a method for estimating an uplink channel using Sounding Reference Signal (SRS) transmission of a terminal will be described. The base station may set at least one SRS configuration for each uplink BWP to deliver configuration information for SRS transmission to the terminal, and may also set at least one SRS resource set for each SRS configuration. As an example, the base station and the terminal may send and receive higher signaling information as follows to deliver information about the SRS resource set.

- srs-ResourceSetId: SRS resource set index

- srs-ResourceIdList: A set of SRS resource indexes referenced by the SRS resource set

- resourceType: Time axis transmission setting of the SRS resource referenced by the SRS resource set, which can be set to one of 'periodic', 'semi-persistent', and 'aperiodic'. If set to 'periodic' or 'semi-persistent', associated CSI-RS information may be provided according to the usage of the SRS resource set. If set to 'aperiodic', an aperiodic SRS resource trigger list and slot offset information may be provided, and associated CSI-RS information may be provided according to the usage of the SRS resource set.

- usage: This is a setting for the usage of the SRS resource referenced by the SRS resource set, and can be set to one of 'beamManagement', 'codebook', 'nonCodebook', and 'antennaSwitching'.

- alpha, p0, pathlossReferenceRS, srs-PowerControlAdjustmentStates: Provides parameter settings for adjusting the transmission power of the SRS resource referenced by the SRS resource set.

The UE can understand that the SRS resource included in the set of SRS resource indexes referenced by the SRS resource set follows the information set in the SRS resource set.

In addition, the base station and the terminal may transmit and receive higher layer signaling information to deliver individual configuration information for the SRS resource. As an example, the individual configuration information for the SRS resource may include time-frequency axis mapping information within a slot of the SRS resource, which may include information on frequency hopping within a slot or between slots of the SRS resource. . In addition, the individual configuration information for the SRS resource may include time axis transmission configuration of the SRS resource, and may be set to one of 'periodic', 'semi-persistent', and 'aperiodic'. This may be limited to having a time axis transmission setting such as an SRS resource set including an SRS resource. If the time axis transmission setting of the SRS resource is set to 'periodic' or 'semi-persistent', an additional SRS resource transmission period and slot offset (eg, periodicityAndOffset) may be included in the time axis transmission setting.

The base station may activate, deactivate, or trigger SRS transmission to the terminal through higher layer signaling including RRC signaling or MAC CE signaling, or L1 signaling (eg, DCI). For example, the base station may activate or deactivate periodic SRS transmission through higher layer signaling to the terminal. The base station may instruct to activate an SRS resource set in which resourceType is set to periodic through higher layer signaling, and the terminal may transmit an SRS resource referred to in the activated SRS resource set. Time-frequency axis resource mapping within the slot of the transmitted SRS resource follows the resource mapping information set in the SRS resource, and slot mapping including transmission period and slot offset follows periodicityAndOffset set in the SRS resource. In addition, the spatial domain transmission filter applied to the transmitted SRS resource may refer to spatial relation info set in the SRS resource or associated CSI-RS information set in the SRS resource set including the SRS resource. The UE may transmit the SRS resource within the uplink BWP activated for the periodic SRS resource activated through higher layer signaling.

For example, the base station may activate or deactivate semi-persistent SRS transmission through higher layer signaling to the terminal. The base station may instruct to activate the SRS resource set through MAC CE signaling, and the terminal may transmit the SRS resource referred to in the activated SRS resource set. An SRS resource set activated through MAC CE signaling may be limited to an SRS resource set whose resourceType is set to semi-persistent. Time-frequency axis resource mapping within the slot of the transmitted SRS resource follows the resource mapping information set in the SRS resource, and slot mapping including transmission period and slot offset follows periodicityAndOffset set in the SRS resource. In addition, the spatial domain transmission filter applied to the transmitted SRS resource may refer to spatial relation info set in the SRS resource or associated CSI-RS information set in the SRS resource set including the SRS resource. If spatial relation info is set in the SRS resource, instead of following it, a spatial domain transmission filter may be determined by referring to configuration information on spatial relation info transmitted through MAC CE signaling for activating semi-persistent SRS transmission. The UE may transmit the SRS resource within the uplink BWP activated for the semi-persistent SRS resource activated through higher layer signaling.

For example, the base station may trigger aperiodic SRS transmission to the terminal through DCI. The base station may indicate one of the aperiodic SRS resource triggers (aperiodicSRS-ResourceTrigger) through the SRS request field of the DCI. The UE can understand that the SRS resource set including the aperiodic SRS resource trigger indicated through the DCI in the aperiodic SRS resource trigger list among the configuration information of the SRS resource set has been triggered. The UE may transmit the SRS resource referred to in the triggered SRS resource set. Time-frequency axis resource mapping within a slot of a transmitted SRS resource follows resource mapping information set in the SRS resource. In addition, slot mapping of the transmitted SRS resource may be determined through a slot offset between the PDCCH including DCI and the SRS resource, which may refer to value (s) included in a slot offset set set in the SRS resource set. Specifically, the slot offset between the PDCCH including the DCI and the SRS resource may apply a value indicated by the time domain resource assignment field of the DCI among the offset value(s) included in the slot offset set set in the SRS resource set. In addition, the spatial domain transmission filter applied to the transmitted SRS resource may refer to spatial relation info set in the SRS resource or associated CSI-RS information set in the SRS resource set including the SRS resource. The UE may transmit an SRS resource within an activated uplink BWP for an aperiodic SRS resource triggered through DCI.

When the base station triggers aperiodic SRS transmission to the terminal through DCI, in order for the terminal to transmit the SRS by applying the configuration information for the SRS resource, the minimum A time interval of (minimum time interval) may be required. The time interval for SRS transmission of the UE is defined as the number of symbols between the last symbol of the PDCCH including the DCI triggering aperiodic SRS transmission and the first symbol to which the first transmitted SRS resource among transmitted SRS resource(s) is mapped. can The minimum time interval may be determined by referring to the PUSCH preparation procedure time required for the UE to prepare for PUSCH transmission. In addition, the minimum time interval may have a different value depending on where an SRS resource set including a transmitted SRS resource is used. For example, the minimum time interval may be defined as an N2 symbol defined by referring to the PUSCH preparation procedure time of the UE and considering UE processing capability according to the capability of the UE. In addition, considering the usage of the SRS resource set including the transmitted SRS resource, if the usage of the SRS resource set is set to 'codebook' or 'antennaSwitching', the minimum time interval is set as N2 symbol, and the usage of the SRS resource set is 'nonCodebook' Alternatively, when set to 'beamManagement', the minimum time interval can be set to N2+14 symbols. The UE transmits the aperiodic SRS when the time interval for aperiodic SRS transmission is greater than or equal to the minimum time interval, and ignores the DCI triggering the aperiodic SRS when the time interval for aperiodic SRS transmission is less than the minimum time interval. can

The spatialRelationInfo setting information in [Table 35] refers to one reference signal and applies the beam information of the reference signal to the beam used for the corresponding SRS transmission. For example, the setting of spatialRelationInfo may include information such as the following [Table 36].

Referring to the spatialRelationInfo setting, an SS/PBCH block index, CSI-RS index, or SRS index may be set as an index of a reference signal to be referred to in order to use beam information of a specific reference signal. Higher signaling referenceSignal is setting information indicating which beam information of a reference signal is referred to for transmission of the corresponding SRS, ssb-Index is the index of the SS/PBCH block, csi-RS-Index is the index of the CSI-RS, and srs is the index of the SRS. each index. If the value of higher signaling referenceSignal is set to 'ssb-Index', the terminal can apply the RX beam used when receiving the SS/PBCH block corresponding to the ssb-Index as the transmit beam of the corresponding SRS transmission. If the value of higher signaling referenceSignal is set to 'csi-RS-Index', the UE can apply the Rx beam used when receiving the CSI-RS corresponding to the csi-RS-Index as the Tx beam of the corresponding SRS transmission. . If the value of higher signaling referenceSignal is set to 'srs', the terminal can apply the transmission beam used when transmitting the SRS corresponding to srs as the transmission beam of the corresponding SRS transmission.

[PUSCH: related to transmission method]

Next, a scheduling method for PUSCH transmission will be described. PUSCH transmission can be dynamically scheduled by a UL grant in DCI or operated by configured grant Type 1 or Type 2. Dynamic scheduling indication for PUSCH transmission is available in DCI format 0_0 or 0_1.

Configured grant Type 1 PUSCH transmission can be semi-statically set through reception of configuredGrantConfig including rrc-ConfiguredUplinkGrant of [Table 37] through higher signaling without reception of UL grant in DCI. Configured grant Type 2 PUSCH transmission can be scheduled semi-persistently by UL grant in DCI after receiving configuredGrantConfig not including rrc-ConfiguredUplinkGrant in [Table 37] through higher signaling. When PUSCH transmission operates by configured grant, parameters applied to PUSCH transmission are [Except for dataScramblingIdentityPUSCH, txConfig, codebookSubset, maxRank, scaling of UCI-OnPUSCH provided by push-Config of [Table 38], which is an upper signaling. It is applied through configuredGrantConfig, which is the upper signaling of Table 37]. If the terminal is provided with transformPrecoder in configuredGrantConfig, which is the upper signaling of [Table 37], the terminal applies tp-pi2BPSK in push-Config of [Table 38] to PUSCH transmission operated by the configured grant.

Next, a PUSCH transmission method will be described. The DMRS antenna port for PUSCH transmission is the same as the antenna port for SRS transmission. PUSCH transmission can follow a codebook-based transmission method and a non-codebook-based transmission method, respectively, depending on whether the value of txConfig in push-Config of [Table 28], which is an upper signaling, is 'codebook' or 'nonCodebook'.

As described above, PUSCH transmission can be dynamically scheduled through DCI format 0_0 or 0_1, and can be semi-statically set by configured grant. If the UE is instructed to schedule PUSCH transmission through DCI format 0_0, the UE performs PUSCH transmission using the pucch-spatialRelationInfoID corresponding to the UE-specific PUCCH resource corresponding to the minimum ID within the uplink BWP activated in the serving cell. Beam configuration for transmission is performed, and at this time, PUSCH transmission is based on a single antenna port. The UE does not expect scheduling for PUSCH transmission through DCI format 0_0 in a BWP in which PUCCH resource including pucch-spatialRelationInfo is not configured. If the UE is not configured with txConfig in push-Config of [Table 38], the UE does not expect to be scheduled in DCI format 0_1.

Next, codebook-based PUSCH transmission will be described. Codebook-based PUSCH transmission can be dynamically scheduled through DCI format 0_0 or 0_1, and can operate quasi-statically by configured grant. If the codebook-based PUSCH is dynamically scheduled by DCI format 0_1 or quasi-statically configured by configured grant, the UE uses the SRS Resource Indicator (SRI), Transmission Precoding Matrix Indicator (TPMI), and transmission rank (PUSCH transmission layer number), a precoder for PUSCH transmission is determined.

At this time, SRI may be given through a field SRS resource indicator in DCI or set through higher signaling, srs-ResourceIndicator. When transmitting codebook-based PUSCH, the terminal receives at least one SRS resource, and can receive up to two SRS resources. When a UE receives SRI through DCI, the SRS resource indicated by the corresponding SRI means an SRS resource corresponding to the SRI among SRS resources transmitted prior to the PDCCH including the corresponding SRI. In addition, TPMI and transmission rank may be given through a field precoding information and number of layers in DCI or set through precodingAndNumberOfLayers, which is a higher level signaling. TPMI is used to indicate a precoder applied to PUSCH transmission. If the UE is configured with one SRS resource, TPMI is used to indicate a precoder to be applied in the configured one SRS resource. If the UE is configured with a plurality of SRS resources, TPMI is used to indicate a precoder to be applied in the SRS resource indicated through the SRI.

A precoder to be used for PUSCH transmission is selected from an uplink codebook having the same number of antenna ports as the value of nrofSRS-Ports in SRS-Config, which is higher signaling. In codebook-based PUSCH transmission, the UE determines a codebook subset based on TPMI and codebookSubset in push-Config, which is higher signaling. CodebookSubset in push-Config, which is higher signaling, may be set to one of 'fullyAndPartialAndNonCoherent', 'partialAndNonCoherent', or 'nonCoherent' based on the UE capability reported by the terminal to the base station. If the terminal reports 'partialAndNonCoherent' as the UE capability, the terminal does not expect the value of codebookSubset, which is higher signaling, to be set to 'fullyAndPartialAndNonCoherent'. In addition, if the terminal reports 'nonCoherent' as the UE capability, the terminal does not expect the value of codebookSubset, which is higher signaling, to be set to 'fullyAndPartialAndNonCoherent' or 'partialAndNonCoherent'. When nrofSRS-Ports in SRS-ResourceSet, which is higher signaling, indicates two SRS antenna ports, the UE does not expect the value of codebookSubset, which is higher signaling, to be set to 'partialAndNonCoherent'.

The terminal can receive one SRS resource set in which the value of usage in the SRS-ResourceSet, which is higher signaling, is set to 'codebook', and one SRS resource in the corresponding SRS resource set can be indicated through SRI. If several SRS resources are set in an SRS resource set in which the usage value in the upper signaling SRS-ResourceSet is set to 'codebook', the UE sets the same value for all SRS resources in the nrofSRS-Ports value in the upper signaling SRS-Resource. expect this to be set.

The terminal transmits one or more SRS resources included in the SRS resource set in which the value of usage is set to 'codebook' to the base station according to higher signaling, and the base station selects one of the SRS resources transmitted by the terminal to correspond to the SRS Instructs the UE to perform PUSCH transmission using the transmission beam information of the resource. At this time, in codebook-based PUSCH transmission, SRI is used as information for selecting an index of one SRS resource and is included in DCI. Additionally, the base station includes information indicating the TPMI and rank to be used by the terminal for PUSCH transmission in the DCI. The UE performs PUSCH transmission by using the SRS resource indicated by the SRI and applying the rank indicated by the transmission beam of the corresponding SRS resource and the precoder indicated by the TPMI.

Next, non-codebook based PUSCH transmission will be described. Non-codebook based PUSCH transmission can be dynamically scheduled through DCI format 0_0 or 0_1, and can operate quasi-statically by configured grant. When at least one SRS resource is set in an SRS resource set in which the value of usage in the SRS-ResourceSet, which is higher signaling, is set to 'nonCodebook', the terminal can receive non-codebook based PUSCH transmission scheduling through DCI format 0_1.

For an SRS resource set in which the value of usage in the SRS-ResourceSet, which is higher signaling, is set to 'nonCodebook', the terminal can receive one connected NZP CSI-RS resource (non-zero power CSI-RS). The UE may calculate a precoder for SRS transmission through measurement of NZP CSI-RS resource connected to the SRS resource set. If the difference between the last received symbol of the aperiodic NZP CSI-RS resource associated with the SRS resource set and the first symbol of aperiodic SRS transmission in the UE is less than 42 symbols, the UE updates the information on the precoder for SRS transmission. don't expect to be

When the value of resourceType in SRS-ResourceSet, which is higher signaling, is set to 'aperiodic', the connected NZP CSI-RS is indicated by SRS request, which is a field in DCI format 0_1 or 1_1. At this time, if the connected NZP CSI-RS resource is an aperiodic NZP CSI-RS resource, the connected NZP CSI-RS exists when the value of the field SRS request in DCI format 0_1 or 1_1 is not '00' will point to At this time, the corresponding DCI must not indicate cross carrier or cross BWP scheduling. In addition, if the value of the SRS request indicates the existence of the NZP CSI-RS, the corresponding NZP CSI-RS is located in the slot where the PDCCH including the SRS request field is transmitted. At this time, the TCI states set for the scheduled subcarriers are not set to QCL-TypeD.

If a periodic or semi-persistent SRS resource set is configured, the connected NZP CSI-RS may be indicated through associatedCSI-RS in the SRS-ResourceSet, which is higher signaling. For non-codebook based transmission, the UE does not expect spatialRelationInfo, which is higher signaling for SRS resource, and associatedCSI-RS in SRS-ResourceSet, which is higher signaling, to be set together.

When a plurality of SRS resources are configured, the UE may determine the precoder and transmission rank to be applied to PUSCH transmission based on the SRI indicated by the base station. At this time, SRI may be indicated through a field SRS resource indicator in DCI or set through higher signaling, srs-ResourceIndicator. Similar to the above-described codebook-based PUSCH transmission, when a UE receives SRI through DCI, the SRS resource indicated by the SRI selects the SRS resource corresponding to the SRI among the SRS resources transmitted prior to the PDCCH including the SRI. it means. The UE can use one or a plurality of SRS resources for SRS transmission, and the maximum number of SRS resources that can be simultaneously transmitted in the same symbol within one SRS resource set and the maximum number of SRS resources are determined by the UE capability reported by the UE to the base station. It is decided. At this time, SRS resources transmitted simultaneously by the UE occupy the same RB. The UE configures one SRS port for each SRS resource. Only one SRS resource set in which the value of usage in the SRS-ResourceSet, which is an upper signaling, is set to 'nonCodebook' can be set, and up to four SRS resources for non-codebook based PUSCH transmission can be set.

The base station transmits one NZP-CSI-RS associated with the SRS resource set to the terminal, and the terminal transmits one or more SRS resources in the corresponding SRS resource set based on the measurement result when receiving the corresponding NZP-CSI-RS Calculate the precoder to use when transmitting. The terminal applies the calculated precoder when transmitting one or more SRS resources in the SRS resource set with usage set to 'nonCodebook' to the base station, and the base station uses one or more of the one or more SRS resources received. Select SRS resource. At this time, in non-codebook based PUSCH transmission, SRI indicates an index capable of expressing a combination of one or a plurality of SRS resources, and the SRI is included in DCI. At this time, the number of SRS resources indicated by the SRI transmitted by the base station may be the number of transmission layers of the PUSCH, and the UE transmits the PUSCH by applying a precoder applied to transmission of the SRS resource to each layer.

[PUSCH: Preparatory Course Hours]

Next, the PUSCH preparation procedure time will be described. When the base station schedules the UE to transmit the PUSCH using DCI format 0_0, 0_1, or 0_2, the UE uses the DCI-instructed transmission method (transmission precoding method of SRS resource, number of transmission layers, spatial domain transmission filter) A PUSCH preparation process time may be required to transmit the PUSCH by applying . NR defined the PUSCH preparation process time considering this. The PUSCH preparation process time of the UE may follow [Equation 4] below.

In Tproc,2 described above with [Equation 4], each variable may have the following meaning.

-N ₂ : The number of symbols determined according to UE processing capability 1 or 2 and numerology μ according to the capabilities of the UE. When reported as UE processing capability 1 according to the capability report of the UE, with the value of [Table 39], when reported as UE processing capability 2 and capable of using UE processing capability 2 is set through higher layer signaling [Table 40] can have a value of

-d _2,1 : The number of symbols determined as 0 when all resource elements of the first OFDM symbol of PUSCH transmission are set to consist of only DM-RS, and 1 otherwise.

- K: 64

- μ: Follows the larger value of T _proc,2 , either μ _DL or μ _UL . μ _DL means downlink numerology through which PDCCH including DCI scheduling PUSCH is transmitted, and μ _UL means uplink numerology through which PUSCH is transmitted.

,

,

를 가진다.- Tc:

,

,

have

-d _2,2 : Follows the BWP switching time when the DCI scheduling the PUSCH indicates BWP switching, otherwise has 0.

- d ₂ : When OFDM symbols of a PUCCH, a PUSCH with a high priority index, and a PUCCH with a low priority index overlap in time, the d ₂ value of the PUSCH with a high priority index is used. Otherwise, d ₂ is 0.

- T _ext : If the UE uses the shared spectrum channel access method, the UE can calculate T _ext and apply it to the PUSCH preparation process time. Otherwise, T _ext is assumed to be zero.

- T _switch : When an uplink switching interval is triggered, T _switch is assumed to be the switching interval time. otherwise, it is assumed to be 0.

When the base station and the terminal consider the time axis resource mapping information of the PUSCH scheduled through the DCI and the effect of the uplink-downlink timing advance, from the last symbol of the PDCCH including the DCI scheduled the PUSCH to after T _proc,2 If the first symbol of the PUSCH starts before the first uplink symbol that the CP starts, it is determined that the PUSCH preparation process time is not sufficient. If not, the base station and the terminal determine that the PUSCH preparation process time is sufficient. The UE may transmit the PUSCH only when the PUSCH preparation time is sufficient, and may ignore the DCI for scheduling the PUSCH when the PUSCH preparation time is not sufficient.

[PUSCH: related to repetitive transmission]

Hereinafter, repetitive transmission of an uplink data channel in a 5G system will be described in detail. The 5G system supports two types, PUSCH repeated transmission type A and PUSCH repeated transmission type B, as repeated transmission methods of an uplink data channel. The UE may be configured with either PUSCH repetitive transmission type A or B through higher layer signaling.

[PUSCH repeated transmission type A]

- As described above, the symbol length of the uplink data channel and the position of the start symbol are determined by the time domain resource allocation method within one slot, and the base station determines the number of repeated transmissions through higher layer signaling (eg RRC signaling) or L1 signaling (For example, DCI) may notify the terminal.

- The terminal can repeatedly transmit an uplink data channel having the same start symbol as the length of the uplink data channel configured based on the number of repeated transmissions received from the base station in consecutive slots. At this time, when at least one symbol of a slot set by the base station to the terminal as downlink or a symbol of an uplink data channel configured by the terminal is set to downlink, the terminal skips transmission of the uplink data channel, but uplink The number of repeated transmissions of the data channel is counted.

[PUSCH repeated transmission type B]

- As described above, the start symbol and length of the uplink data channel are determined by the time domain resource allocation method within one slot, and the base station sets the number of repetitions of repeated transmissions through upper signaling (eg, RRC signaling) or L1 signaling (eg, For example, the UE may be notified through DCI).

에 의해 주어지고 그 슬롯에서 시작하는 심볼은 mod(S+n*L, N_symb ^slot)에 의해 주어진다. n번째 nominal repetition이 끝나는 슬롯은

에 의해 주어지고 그 슬롯에서 끝나는 심볼은 mod(S+(n+1)*L-1, N_symb ^slot)에 의해 주어진다. 여기서 n=0,..., numberofrepetitions-1 이고 S는 설정 받은 상향링크 데이터 채널의 시작 심볼 L은 설정 받은 상향링크 데이터 채널의 심볼 길이를 나타낸다. K_S는 PUSCH 전송이 시작하는 슬롯을 나타내고 N_symb ^slot은 슬롯당 심볼의 수를 나타낸다.First, the nominal repetition of the uplink data channel is determined as follows based on the set start symbol and length of the uplink data channel. The slot where the nth nominal repetition starts is

and the symbol starting in that slot is given by mod(S+n*L, N _symb ^slot ). The slot where the nth nominal repetition ends is

The symbol given by and ending in that slot is given by mod(S+(n+1)*L-1, N _symb ^slot ). Here, n = 0, ..., numberofrepetitions-1, S is the start symbol of the configured uplink data channel, L represents the symbol length of the configured uplink data channel. K _S represents a slot in which PUSCH transmission starts, and N _symb ^slot represents the number of symbols per slot.

- The UE determines an invalid symbol for PUSCH repetitive transmission type B. A symbol configured for downlink by tdd-UL-DL-ConfigurationCommon or tdd-UL-DL-ConfigurationDedicated is determined as an invalid symbol for PUSCH repeated transmission type B. Additionally, invalid symbols can be set in higher-level parameters (e.g. InvalidSymbolPattern). A higher layer parameter (e.g. InvalidSymbolPattern) provides a symbol-level bitmap spanning one slot or two slots so that invalid symbols can be set. 1 in the bitmap represents an invalid symbol. Additionally, the period and pattern of the bitmap may be set through a higher layer parameter (for example, periodicityAndPattern). If a higher layer parameter (eg InvalidSymbolPattern) is set and the InvalidSymbolPatternIndicator-ForDCIFormat0_1 or InvalidSymbolPatternIndicator-ForDCIFormat0_2 parameter indicates 1, the terminal applies the invalid symbol pattern, and if the parameter indicates 0, the terminal does not apply the invalid symbol pattern. If the upper layer parameter (eg InvalidSymbolPattern) is set and the InvalidSymbolPatternIndicator-ForDCIFormat0_1 or InvalidSymbolPatternIndicator-ForDCIFormat0_2 parameter is not set, the terminal applies the invalid symbol pattern.

After the invalid symbol is determined, for each nominal repetition, the terminal may consider symbols other than the invalid symbol as valid symbols. If more than one valid symbol is included in each nominal repetition, the nominal repetition may include one or more actual repetitions. Here, each actual repetition includes a contiguous set of valid symbols that can be used for PUSCH repeated transmission type B in one slot.

17 illustrates an example of a PUSCH repetitive transmission type in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 17 is a diagram illustrating an example of PUSCH repeated transmission type B in a wireless communication system according to an embodiment of the present disclosure. The terminal may set the start symbol S of the uplink data channel to 0 and the length L of the uplink data channel to 14, and set the number of repeated transmissions to 16. In this case, nominal repetition is indicated in 16 consecutive slots (1701). After that, the terminal may determine a symbol set as a downlink symbol in each nominal repetition 1701 as an invalid symbol. In addition, the terminal determines symbols set to 1 in invalid symbol pattern 1702 as invalid symbols. In each nominal repetition, when valid symbols, not invalid symbols, consist of one or more consecutive symbols in one slot, they are set as actual repetitions and transmitted (1703).

In addition, for repeated PUSCH transmission, NR Release 16 may define the following additional methods for UL grant-based PUSCH transmission and configured grant-based PUSCH transmission across slot boundaries.

1. Method 1 (mini-slot level repetition): Through one UL grant, two or more repeated PUSCH transmissions are scheduled within one slot or across the boundary of consecutive slots. Also, for method 1, time domain resource allocation information in DCI indicates resources of the first repeated transmission. In addition, time domain resource information of the remaining repeated transmissions may be determined according to time domain resource information of the first repeated transmission and an uplink or downlink direction determined for each symbol of each slot. Each repeated transmission occupies consecutive symbols.

2. Method 2 (multi-segment transmission): Two or more repeated PUSCH transmissions are scheduled in consecutive slots through one UL grant. At this time, one transmission is designated for each slot, and different start points or repetition lengths may be different for each transmission. Also, in method 2, the time domain resource allocation information in the DCI indicates the start point and repetition length of all repeated transmissions. In addition, when repeated transmission is performed within a single slot through method 2, if there are several bundles of consecutive uplink symbols in the corresponding slot, each repeated transmission is performed for each bundle of uplink symbols. If a bundle of consecutive uplink symbols exists uniquely in the corresponding slot, one repetition of PUSCH transmission is performed according to the method of NR Release 15.

3. Method 3: Two or more repeated PUSCH transmissions are scheduled in consecutive slots through two or more UL grants. At this time, one transmission is designated for each slot, and the n-th UL grant can be received before the PUSCH transmission scheduled for the n-1-th UL grant ends.

4. Method 4: Through one UL grant or one configured grant, one or several PUSCH repeated transmissions within a single slot, or two or more PUSCH repeated transmissions across the boundary of consecutive slots Can be supported. there is. The number of repetitions indicated by the base station to the terminal is only a nominal value, and the number of repeated PUSCH transmissions actually performed by the terminal may be greater than the nominal number of repetitions. Time domain resource allocation information within the DCI or within the configured grant means the resource of the first repeated transmission indicated by the base station. Time domain resource information of the remaining repeated transmissions may be determined by referring to resource information of at least the first repeated transmission and uplink or downlink directions of symbols. If the time domain resource information of repeated transmission indicated by the base station spans a slot boundary or includes an uplink/downlink switching point, the repeated transmission may be divided into a plurality of repeated transmissions. In this case, one repetitive transmission may be included for each uplink period in one slot.

[PUSCH: frequency hopping process]

In the following, frequency hopping of a physical uplink shared channel (PUSCH) in a 5G system will be described in detail.

In 5G, as a frequency hopping method of an uplink data channel, two methods are supported for each PUSCH repeated transmission type. First, PUSCH repetition transmission type A supports intra-slot frequency hopping and inter-slot frequency hopping, and PUSCH repetition transmission type B supports inter-repetition frequency hopping and inter-slot frequency hopping.

The intra-slot frequency hopping method supported by PUSCH repetitive transmission type A is a method in which a terminal changes and transmits allocated resources in a frequency domain by a set frequency offset in two hops within one slot. In intra-slot frequency hopping, the starting RB of each hop can be expressed through [Equation 5].

로 나타낼 수 있고, 두번째 홉의 심볼 수는

으로 나타낼 수 있다. N_symb ^PUSCH,S은 한 슬롯 내에서의 PUSCH 전송의 길이로, OFDM 심볼 수로 나타난다. In [Equation 5], i = 0 and i = 1 represent the first hop and the second hop, respectively, and RB _start represents the starting RB in the UL BWP and is calculated from the frequency resource allocation method. RB _offset represents a frequency offset between two hops through a higher layer parameter. The number of symbols in the first hop is

, and the number of symbols in the second hop is

can be expressed as N _symb ^PUSCH,S is the length of PUSCH transmission in one slot, represented by the number of OFDM symbols.

Next, the inter-slot frequency hopping method supported by PUSCH repetitive transmission types A and B is a method in which the UE changes and transmits allocated resources in the frequency domain by a set frequency offset for each slot. In inter-slot frequency hopping, the start RB during n _s ^μ slots can be expressed through [Equation 6].

In [Equation 6], n _s ^μ is the current slot number in multi-slot PUSCH transmission, and RB _start indicates the starting RB in the UL BWP and is calculated from the frequency resource allocation method. RB _offset represents a frequency offset between two hops through a higher layer parameter.

Next, the inter-repetition frequency hopping method supported by PUSCH repeated transmission type B moves and transmits resources allocated in the frequency domain for one or a plurality of actual repetitions within each nominal repetition by a set frequency offset. RB _start (n), which is an index of a start RB in the frequency domain for one or a plurality of actual repetitions within the n-th nominal repetition, may follow [Equation 7] below.

In Equation 7, n is an index of nominal repetition, and RB _offset represents an RB offset between two hops through a higher layer parameter.

[Regarding device capability reporting]

In LTE and NR, the terminal may perform a procedure for reporting the capability supported by the terminal to the corresponding base station while connected to the serving base station. In the description below, this is referred to as a UE capability report.

The base station may transmit a UE capability inquiry message requesting a capability report to a UE in a connected state. The message may include a UE capability request for each radio access technology (RAT) type of the base station. The request for each RAT type may include supported frequency band combination information. In addition, in the case of the terminal capability inquiry message, UE capabilities for each RAT type may be requested through one RRC message container transmitted by the base station, or the base station sends a terminal capability inquiry message including a terminal capability request for each RAT type. It can be included multiple times and delivered to the terminal. That is, the UE capability query is repeated multiple times within one message, and the UE can configure and report a UE capability information message corresponding to the UE capability information message multiple times. In the next-generation mobile communication system, a UE capability request for MR-DC (Multi-RAT dual connectivity) including NR, LTE, and EN-DC (E-UTRA-NR dual connectivity) can be requested. In addition, although the terminal capability inquiry message is generally initially transmitted after the terminal connects to the base station, the base station may request it under any condition when necessary.

In the above step, the terminal receiving the UE capability report request from the base station configures the terminal capability according to the RAT type and band information requested from the base station. Below is a summary of how the UE configures UE capabilities in the NR system.

One. If the terminal receives a list of LTE and/or NR bands from the base station as a UE capability request, the terminal configures a band combination (BC) for EN-DC and NR stand alone (SA). That is, BC candidate lists for EN-DC and NR SA are configured based on the bands requested to the base station through FreqBandList. In addition, bands have priorities in the order described in FreqBandList.

2. If the base station requests UE capability reporting by setting the "eutra-nr-only" flag or the "eutra" flag, the terminal completely removes those for NR SA BCs from the configured BC candidate list. This operation may occur only when the LTE base station (eNB) requests the "eutra" capability.

3. Thereafter, the terminal removes fallback BCs from the candidate list of BCs configured in the above step. Here, the fallback BC means a BC that can be obtained by removing a band corresponding to at least one SCell from any BC, and since the BC before removing the band corresponding to at least one SCell can already cover the fallback BC, can be omitted. This step also applies to MR-DC, ie LTE bands as well. The remaining BCs after this step are the final "candidate BC list".

4. The terminal selects BCs to be reported by selecting BCs suitable for the requested RAT type from the final "candidate BC list". In this step, the terminal configures the supportedBandCombinationList in a predetermined order. That is, the terminal configures the BC and UE capabilities to be reported according to the order of the preset rat-Type. (nr -> eutra-nr -> eutra). In addition, featureSetCombination is configured for the configured supportedBandCombinationList, and a list of "candidate feature set combination" is configured in the candidate BC list from which the list for fallback BC (including capabilities of the same or lower level) is removed. The above "candidate feature set combination" includes both feature set combinations for NR and EUTRA-NR BC, and can be obtained from the feature set combination of the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

5. In addition, if the requested rat Type is eutra-nr and has an effect, featureSetCombinations is included in both containers of UE-MRDC-Capabilities and UE-NR-Capabilities. However, the feature set of NR includes only UE-NR-Capabilities.

After the terminal capabilities are configured, the terminal transmits a terminal capability information message including the terminal capabilities to the base station. Based on the terminal capabilities received from the terminal, the base station then performs appropriate scheduling and transmission/reception management for the corresponding terminal.

[CA/DC related]

18 illustrates an example of a radio protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 18 is a diagram illustrating a radio protocol structure of a base station and a terminal in a single cell, carrier aggregation, and dual connectivity situation according to an embodiment of the present disclosure.

Referring to FIG. 18, the radio protocols of the next-generation mobile communication system are NR SDAP (Service Data Adaptation Protocol 1825 and 1870), NR PDCP (Packet Data Convergence Protocol 1830 and 1865), and NR RLC (Radio Link Control) in the terminal and NR base station, respectively. 1835 and 1860) and NR MAC (Medium Access Control 1840 and 1855).

The main functions of the NR SDAPs 1825 and 1870 may include some of the following functions.

- Transfer of user plane data

- A mapping function between a QoS flow and a data bearer for uplink and downlink (mapping between a QoS flow and a DRB for both DL and UL)

- Marking function of QoS flow ID for uplink and downlink (marking QoS flow ID in both DL and UL packets)

- Function to map reflective QoS flow to data bearer for UL SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

Regarding the SDAP layer device, the terminal may receive a RRC message to set whether to use the header of the SDAP layer device or the function of the SDAP layer device for each PDCP layer device, each bearer, or each logical channel, and SDAP header is set, the 1-bit NAS QoS reflection setting indicator (NAS reflective QoS) and the 1-bit AS QoS reflection setting indicator (AS reflective QoS) of the SDAP header allow the UE to send uplink and downlink QoS flows and data bearer mapping information can be instructed to update or reset. The SDAP header may include QoS flow ID information indicating QoS. The QoS information may be used as data processing priority and scheduling information to support smooth service.

The main functions of the NR PDCP (S30, S65) may include some of the following functions.

- Header compression and decompression (ROHC only)

- Transfer of user data

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- PDCP PDU reordering for reception

- Duplicate detection of lower layer SDUs

- Retransmission of PDCP SDUs

- Ciphering and deciphering

- Timer-based SDU discard in uplink.

In the above, the reordering function of the NR PDCP device refers to a function of rearranging PDCP PDUs received from a lower layer in order based on a PDCP SN (sequence number), and a function of transmitting data to an upper layer in the rearranged order can include Alternatively, the reordering function of the NR PDCP device may include a function of immediately forwarding without considering the order, and may include a function of reordering and recording lost PDCP PDUs, and the lost PDCP A function of reporting the status of PDUs to the transmitter may be included, and a function of requesting retransmission of lost PDCP PDUs may be included.

The main functions of the NR RLC (S35 and S60) may include some of the following functions.

- Transfer of upper layer PDUs

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- ARQ function (Error Correction through ARQ)

- Concatenation, segmentation and reassembly of RLC SDUs

- Re-segmentation of RLC data PDUs

- Reordering of RLC data PDUs

- Duplicate detection

- Error detection function (Protocol error detection)

- RLC SDU discard function (RLC SDU discard)

- RLC re-establishment

In-sequence delivery of the NR RLC device in the above means a function of sequentially delivering RLC SDUs received from a lower layer to an upper layer. The in-sequence delivery function of the NR RLC device may include a function of reassembling and transmitting the received RLC SDU when one RLC SDU is divided into several RLC SDUs, and transmits the received RLC PDUs It may include a function of reordering based on RLC sequence number (SN) or PDCP sequence number (SN), and may include a function of reordering and recording lost RLC PDUs. A function of reporting the status to the transmitter may be included, and a function of requesting retransmission of lost RLC PDUs may be included. In-sequence delivery of the NR RLC device may include, when there is a lost RLC SDU, a function of delivering only RLC SDUs prior to the lost RLC SDU to the upper layer in order, or Even if there are RLC SDUs, if a predetermined timer expires, a function of sequentially delivering all received RLC SDUs to an upper layer before the timer starts may be included. Alternatively, the in-sequence delivery function of the NR RLC device may include a function of sequentially delivering all RLC SDUs received up to now to a higher layer if a predetermined timer expires even if there is a lost RLC SDU. In addition, RLC PDUs may be processed in the order in which they are received (regardless of the order of serial numbers and sequence numbers, in the order of arrival) and delivered to the PDCP device regardless of order (out-of sequence delivery). In , segments stored in a buffer or to be received later may be received, reconstructed into one complete RLC PDU, processed, and transmitted to the PDCP device. The NR RLC layer may not include a concatenation function, and the function may be performed in the NR MAC layer or replaced with a multiplexing function of the NR MAC layer.

In the above, the out-of-sequence delivery function of the NR RLC device refers to a function of immediately delivering RLC SDUs received from a lower layer to an upper layer regardless of the order, and originally one RLC SDU is multiple RLC When received divided into SDUs, it may include a function of reassembling and forwarding them, and may include a function of storing RLC SNs or PDCP SNs of received RLC PDUs and arranging them in order to record lost RLC PDUs. can

The NR MACs 1840 and 1855 may be connected to several NR RLC layer devices configured in one terminal, and the main functions of the NR MAC may include some of the following functions.

- Mapping between logical channels and transport channels

- Multiplexing/demultiplexing of MAC SDUs

- Scheduling information reporting

- HARQ function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification

- Transport format selection

- Padding function (Padding)

The NR PHY layers 1845 and 1850 channel code and modulate higher layer data, convert OFDM symbols into OFDM symbols and transmit them through a radio channel, or demodulate OFDM symbols received through a radio channel, channel decode, and transmit the data to the upper layer. can be done

The detailed structure of the radio protocol structure may be variously changed according to a carrier (or cell) operation method. For example, when a base station transmits data to a terminal based on a single carrier (or cell), the base station and the terminal use a protocol structure having a single structure for each layer, such as 1800. On the other hand, when the base station transmits data to the terminal based on CA (carrier aggregation) using multiple carriers in a single TRP, the base station and the terminal have a single structure up to RLC as in 1810, but a protocol for multiplexing the PHY layer through the MAC layer structure will be used. As another example, when a base station transmits data to a terminal based on DC (dual connectivity) using multiple carriers in multiple TRPs, the base station and the terminal have a single structure up to RLC as in 1820, but the PHY layer through the MAC layer A protocol structure for multiplexing is used.

Referring to the descriptions related to the PDCCH and beam configuration described above, it is difficult to achieve the required reliability in scenarios requiring high reliability such as URLLC because repetitive PDCCH transmission is not currently supported in Rel-15 and Rel-16 NRs. The present invention provides a method for repeatedly transmitting a PDCCH through multiple transmission points (TRPs) to improve PDCCH reception reliability of a terminal. Specific methods are described in detail in the following examples.

Hereinafter, embodiments of the present disclosure will be described in detail with accompanying drawings. The contents of this disclosure are applicable to FDD and TDD systems. Hereinafter, higher signaling (or higher layer signaling) in the present disclosure is a method of transmitting a signal from a base station to a terminal using a downlink data channel of a physical layer, or from a terminal to a base station using an uplink data channel of the physical layer, It may also be referred to as RRC signaling, PDCP signaling, or a medium access control (MAC) control element (MAC CE).

Hereinafter, in the present disclosure, in determining whether cooperative communication is applied, a PDCCH (s) allocated to a PDSCH to which cooperative communication is applied has a specific format, or a PDCCH (s) allocated to a PDSCH to which cooperative communication is applied is cooperative. Include a specific indicator indicating whether or not communication is applied, or PDCCH(s) allocating a PDSCH to which cooperative communication is applied are scrambled with a specific RNTI, or cooperative communication is assumed in a specific interval indicated by a higher layer, etc. It is possible to use various methods. For convenience of explanation, the terminal receiving the PDSCH to which cooperative communication is applied based on conditions similar to the above will be referred to as an NC-JT case.

Hereinafter, in the present disclosure, determining the priority between A and B means selecting a higher priority according to a predetermined priority rule and performing a corresponding operation or lower priority. It may be variously referred to as omitting or dropping an operation for.

Hereinafter, in the present disclosure, the above examples are described through a plurality of embodiments, but they are not independent, and one or more embodiments may be applied simultaneously or in combination.

[NC-JT related]

According to an embodiment of the present disclosure, Non-Coherent Joint Transmission (NC-JT) may be used for a UE to receive PDSCHs from multiple TRPs.

The 5G wireless communication system can support not only services requiring high transmission rates, but also services with very short transmission delays and services requiring high connection density, unlike conventional ones. In a wireless communication network including multiple cells, transmission and reception points (TRPs), or beams, coordinated transmission between each cell, TRP or/and beam increases the strength of a signal received by a terminal or each cell , TRP or/and inter-beam interference control can be efficiently performed to satisfy various service requirements.

Joint Transmission (JT) is a typical transmission technology for the above-described cooperative communication, and transmits a signal to one UE through a plurality of different cells, TRPs, or/and beams, thereby transmitting the strength or throughput of the signal received by the UE. is a technique that increases At this time, the characteristics of the channel between each cell, TRP or / and beam and the terminal may be significantly different, and in particular, a channel supporting non-coherent precoding between each cell, TRP or / and beam In the case of Non-Coherent Joint Transmission (NC-JT), individual precoding, MCS, resource allocation, TCI indication, etc. are required according to channel characteristics of each cell, TRP or/and link between beams and UEs. can

The aforementioned NC-JT transmission includes a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH), and an uplink control channel. (physical uplink control channel, PUCCH). During PDSCH transmission, transmission information such as precoding, MCS, resource allocation, and TCI is indicated as DL DCI, and for NC-JT transmission, the transmission information must be independently indicated for each cell, TRP or/and beam. This becomes a major factor in increasing a payload required for DL DCI transmission, which may adversely affect reception performance of a PDCCH transmitting DCI. Therefore, it is necessary to carefully design the tradeoff between DCI information amount and control information reception performance for JT support of PDSCH.

19 illustrates an example of antenna port configuration and resource allocation for cooperative communication in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 19 is a diagram illustrating an antenna port configuration and resource allocation example for transmitting a PDSCH using cooperative communication in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 19, examples for PDSCH transmission are described for each technique of joint transmission (JT), and examples for allocating radio resources for each TRP are shown.

Referring to FIG. 19 , an example N000 for coherent joint transmission (C-JT) supporting coherent precoding between each cell, TRP or/and beam is shown.

In the case of C-JT, TRP A 1905 and TRP B 1910 transmit single data (PDSCH) to UE 1915, and joint precoding may be performed on multiple TRPs. This may mean that DMRS is transmitted through the same DMRS ports so that TRP A (1905) and TRP B (1910) transmit the same PDSCH. For example, each of TRP A (1905) and TRP B (1910) may transmit DRMS to the UE through DMRS port A and DMRS B. In this case, the terminal may receive one DCI information for receiving one PDSCH demodulated based on DMRS transmitted through DMRS port A and DMRS B.

19 is an example of non-coherent joint transmission (NC-JT) supporting non-coherent precoding between each cell, TRP or / and beam for PDSCH transmission ( 1920).

In the case of NC-JT, a PDSCH is transmitted to the terminal 1935 for each cell, TRP or/and beam, and individual precoding may be applied to each PDSCH. Each cell, TRP or/and beam may transmit different PDSCHs or different PDSCH layers to the UE to improve throughput compared to transmission of a single cell, TRP or/and beam. In addition, each cell, TRP or / and beam repeatedly transmits the same PDSCH to the UE, thereby improving reliability compared to single cell, TRP or / and beam transmission. For convenience of description, a cell, a TRP, or/and a beam are collectively referred to as TRP below.

At this time, if the frequency and time resources used by multiple TRPs for PDSCH transmission are the same (1940), if the frequency and time resources used by multiple TRPs do not overlap at all (1945), in multiple TRPs Various radio resource allocations may be considered, such as when some of the used frequency and time resources overlap (1950).

To support NC-JT, DCIs of various forms, structures, and relationships may be considered in order to simultaneously allocate a plurality of PDSCHs to one UE.

20 illustrates an example of configuration of downlink control information (DCI) for cooperative communication in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 20 shows downlink control information (DCI) for NC-JT in which each TRP transmits a different PDSCH or a different PDSCH layer to a terminal in a wireless communication system according to an embodiment of the present disclosure. It is a diagram showing an example of the configuration of.

Referring to FIG. 20, in case #1 (2000), in addition to the serving TRP (TRP#0) used during single PDSCH transmission, (N-1) additional TRPs (TRP#1 to TRP#(N-1)) In a situation where different (N-1) PDSCHs are transmitted, this is an example in which control information on PDSCHs transmitted in (N-1) additional TRPs is transmitted independently of control information about PDSCHs transmitted in serving TRPs. . That is, the terminal transmits control information on PDSCHs transmitted from different TRPs (TRP#0 to TRP#(N-1)) through independent DCIs (DCI#0 to DCI#(N-1)). can be obtained The formats of the independent DCIs may be the same or different, and the payloads of the DCIs may also be the same or different. In Case #1 described above, each PDSCH control or allocation degree of freedom can be completely guaranteed, but when each DCI is transmitted in different TRPs, a coverage difference for each DCI may occur, resulting in deterioration in reception performance.

Case #2 (2005) is different from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) in addition to the serving TRP (TRP#0) used in single PDSCH transmission. In a situation where ) PDSCHs are transmitted, control information (DCI) for the PDSCHs of (N-1) additional TRPs is transmitted, and each of these DCIs is dependent on the control information for the PDSCHs transmitted from the serving TRP. see.

For example, in the case of DCI#0, which is control information for the PDSCH transmitted from the serving TRP (TRP#0), it includes all information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2, but the cooperative TRP DCI format 1_0, It may include only some of the information elements of DCI format 1_1 and DCI format 1_2. Therefore, in the case of sDCI that transmits control information for PDSCHs transmitted from cooperative TRPs, compared to nDCI because the payload is smaller than normal DCI (nDCI) that transmits PDSCH-related control information transmitted from serving TRPs. Thus, it is possible to include reserved bits.

In case #2 described above, although the degree of freedom in controlling or allocating each PDSCH may be limited according to the content of the information element included in the sDCI, the reception performance of the sDCI is superior to the nDCI, so a difference in coverage for each DCI may occur. odds may be lower.

Case #3 (2010) is different (N-1) from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) other than the serving TRP (TRP#0) used in single PDSCH transmission. ) PDSCHs are transmitted, one control information for the PDSCHs of (N-1) additional TRPs is transmitted, and this DCI is dependent on the control information for the PDSCHs transmitted from the serving TRP.

For example, in the case of DCI#0, which is control information for the PDSCH transmitted from the serving TRP (TRP#0), it includes all information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2, and the cooperative TRP In the case of control information for PDSCHs transmitted from TRP#1 to TRP#(N-1), only some of the information elements of DCI format 1_0, DCI format 1_1, and DCI format 1_2 are used as one 'secondary' DCI ( sDCI) and can be transmitted. For example, the sDCI may include at least one of HARQ-related information such as frequency domain resource assignment, time domain resource assignment, and MCS of cooperative TRPs. In addition, information not included in sDCI, such as a bandwidth part (BWP) indicator or carrier indicator, may follow the DCI (DCI#0, normal DCI, nDCI) of the serving TRP.

In Case #3 (2010), each PDSCH control or allocation degree of freedom may be limited according to the content of the information element included in the sDCI, but the reception performance of the sDCI can be adjusted, and Case #1 (2000) or Case #2 Compared to (2005), the complexity of DCI blind decoding of the terminal may be reduced.

Case #4 (2015) is different from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) in addition to the serving TRP (TRP#0) used during single PDSCH transmission. In a situation where ) PDSCHs are transmitted, control information for PDSCHs transmitted from (N-1) additional TRPs is transmitted in the same DCI (Long DCI) as control information for PDSCHs transmitted from serving TRPs. This is an example. That is, the terminal can obtain control information on PDSCHs transmitted from different TRPs (TRP#0 to TRP#(N-1)) through a single DCI. In case #4 (2015), the complexity of DCI blind decoding of the UE may not increase, but the degree of freedom in PDSCH control or allocation may be low, such as the number of cooperative TRPs being limited according to the long DCI payload limit.

In the following description and embodiments, sDCI may refer to various auxiliary DCIs, such as shortened DCI, secondary DCI, or normal DCI (DCI format 1_0 to 1_1 described above) including PDSCH control information transmitted from cooperative TRP, and has special restrictions. If not specified, the description is similarly applicable to the various auxiliary DCIs.

In the following descriptions and embodiments, case #1 (2000), case #2 (2005), and case #3 (2010) in which one or more DCI (PDCCH) is used to support NC-JT are based on multiple PDCCHs. It is classified as NC-JT, and the case of the aforementioned case #4 (2015) in which a single DCI (PDCCH) is used to support NC-JT can be classified as a single PDCCH-based NC-JT. In multiple PDCCH-based PDSCH transmission, a CORESET in which DCI of serving TRP (TRP#0) is scheduled and a CORESET in which DCI of cooperative TRPs (TRP#1 to TRP#(N-1)) are scheduled can be distinguished. As a method for distinguishing CORESETs, there may be a method of distinguishing through an upper layer indicator for each CORESET, a method of distinguishing through beam setting for each CORESET, and the like. In addition, in the single PDCCH-based NC-JT, a single DCI schedules a single PDSCH having a plurality of layers instead of scheduling a plurality of PDSCHs, and the above-described plurality of layers can be transmitted from a plurality of TRPs. At this time, the connection relationship between the layer and the TRP transmitting the layer may be indicated through a transmission configuration indicator (TCI) indication for the layer.

In the embodiments of the present disclosure, "cooperative TRP" may be replaced with various terms such as "cooperative panel" or "cooperative beam" in actual application.

In the embodiments of the present disclosure, "when NC-JT is applied" means "when the terminal simultaneously receives one or more PDSCHs in one BWP", "when the terminal simultaneously receives two or more TCIs (Transmission Configuration It is possible to interpret variously according to the situation, such as "when PDSCH is received based on Indicator) indication" and "when the PDSCH received by the terminal is associated with one or more DMRS port groups". For convenience, one expression is used.

In the present invention, the radio protocol structure for NC-JT can be used in various ways according to TRP deployment scenarios. For example, if there is no or small backhaul delay between cooperative TRPs, a method using a structure based on MAC layer multiplexing (CA-like method) is possible. On the other hand, when the backhaul delay between cooperative TRPs is too large to be ignored (for example, when information exchange between cooperative TRPs such as CSI, scheduling, and HARQ-ACK takes more than 2 ms), it is similar to S20 of x4. It is possible to obtain a robust characteristic against delay by using an independent structure for each TRP from the RLC layer (DC-like method).

A UE supporting C-JT/NC-JT may receive parameters or setting values related to C-JT/NC-JT from higher layer settings, and set RRC parameters of the UE based on this. For higher layer configuration, the UE may utilize a UE capability parameter, for example, tci-StatePDSCH. Here, the UE capability parameter, for example, tci-StatePDSCH, can define TCI states for the purpose of PDSCH transmission, and the number of TCI states is 4, 8, 16, 32, 64, 128 in FR1 and 64, 128 in FR2 , and among the set number, up to 8 states that can be indicated by the TCI field 3 bits of the DCI through the MAC CE message can be set. The maximum value of 128 means a value indicated by maxNumberConfiguredTCIstatesPerCC in the tci-StatePDSCH parameter included in capability signaling of the UE. As such, a series of configuration processes from higher layer configuration to MAC CE configuration may be applied to a beamforming instruction or a beamforming change command for at least one PDSCH in one TRP.

[Multi-DCI based Multi-TRP]

As an embodiment of the present disclosure, a multi-DCI based multi-TRP transmission method will be described. In the multi-DCI-based multi-TRP transmission method, a downlink control channel for NC-JT transmission may be set based on the Multi-PDCCH.

In NC-JT based on multiple PDCCHs, when DCI is transmitted for the PDSCH schedule of each TRP, it is possible to have a CORESET or search space classified for each TRP. CORESET or search space for each TRP can be set in at least one of the following cases.

1. Upper layer index setting for each CORESET: The CORESET setting information set for the upper layer may include an index value, and the TRP transmitting the PDCCH in the corresponding CORESET can be distinguished by the index value for each set CORESET. That is, in a set of CORESETs having the same higher layer index value, it may be considered that the same TRP transmits the PDCCH or the PDCCH scheduling the PDSCH of the same TRP is transmitted. The index for each CORESET described above may be named as CORESETPoolIndex, and it may be considered that the PDCCH is transmitted from the same TRP for CORESETs for which the same CORESETPoolIndex value is set. In the case of a CORESET in which the CORESETPoolIndex value is not set, it can be considered that the default value of CORESETPoolIndex is set, and the above-described default value may be 0.

(One) In the present disclosure, if the type of CORESETPoolIndex each of a plurality of CORESETs included in PDCCH-Config, which is higher layer signaling, exceeds one, that is, if each CORESET has a different CORESETPoolIndex, the UE determines that the base station is multi- It can be considered that a DCI-based multi-TRP transmission method can be used.

(2) Unlike this, in the present disclosure, if the type of CORESETPoolIndex each of a plurality of CORESETs included in PDCCH-Config, which is higher layer signaling, has one, that is, if all CORESETs have the same CORESETPoolIndex of 0 or 1, the terminal is a base station It can be regarded as transmission using single-TRP without using this multi-DCI based multi-TRP transmission method.

2. Multiple PDCCH-Config settings: Multiple PDCCH-Configs are configured in one BWP, and each PDCCH-Config may include PDCCH settings for each TRP. That is, a list of CORESETs for each TRP and/or a list of search spaces for each TRP can be configured in one PDCCH-Config, and one or more CORESETs and one or more search spaces included in one PDCCH-Config are considered to correspond to a specific TRP. can do.

3. CORESET beam/beam group configuration: TRPs corresponding to the corresponding CORESETs can be distinguished through beams or beam groups set for each CORESET. For example, when the same TCI state is set in a plurality of CORESETs, it can be considered that the corresponding CORESETs are transmitted through the same TRP or a PDCCH scheduling the PDSCH of the same TRP is transmitted in the corresponding CORESET.

4. Configuration of search space beams/beam groups: A beam or beam group is configured for each search space, and through this, TRPs for each search space can be distinguished. For example, when the same beam/beam group or TCI state is set in multiple search spaces, it can be considered that the same TRP transmits the PDCCH in the search space, or the PDCCH scheduling the PDSCH of the same TRP is transmitted in the search space. there is.

As described above, by classifying the CORESET or search space for each TRP, it is possible to classify PDSCH and HARQ-ACK information for each TRP, and through this, independent HARQ-ACK codebook generation and independent PUCCH resource use for each TRP are possible.

The above setting may be independent for each cell or each BWP. For example, while two different CORESETPoolIndex values are set for PCell, no CORESETPoolIndex value may be set for a specific SCell. In this case, it can be considered that NC-JT transmission is configured in the PCell, whereas NC-JT transmission is not configured in the SCell for which the CORESETPoolIndex value is not set.

The PDSCH TCI state activation/deactivation MAC-CE applicable to the multi-DCI based multi-TRP transmission method may follow FIG. 16. If the UE does not set the CORESETPoolIndex for each of all CORESETs in the upper layer signaling PDCCH-Config, the UE can ignore the CORESET Pool ID field 1655 in the corresponding MAC-CE 1650. If the UE can support the multi-DCI-based multi-TRP transmission method, that is, if each CORESET in the upper layer signaling PDCCH-Config has a different CORESETPoolIndex, the UE can support the CORESET Pool in the corresponding MAC-CE 1650. The TCI state in the DCI included in the PDCCH transmitted in CORESETs having the same CORESETPoolIndex value as the ID field 1655 can be activated. For example, if the value of the CORESET Pool ID field 1655 in the corresponding MAC-CE 1650 is 0, the TCI state in the DCI included in the PDCCH transmitted from CORESETs having a CORESETPoolIndex of 0 follows the activation information of the corresponding MAC-CE. can

When the terminal is configured to use the multi-DCI based multi-TRP transmission method from the base station, that is, when the number of CORESETPoolIndex types each of the plurality of CORESETs included in PDCCH-Config, which is higher layer signaling, exceeds one, or When each CORESET has a different CORESETPoolIndex, the UE can know that the following restrictions exist for PDSCHs scheduled from PDCCHs in each CORESET having two different CORESETPoolIndexes.

One. When PDSCHs indicated from PDCCHs in each CORESET having two different CORESETPoolIndexes completely or partially overlap, the UE can apply TCI states indicated from each PDCCH to different CDM groups, respectively. That is, two or more TCI states may not be applied to one CDM group.

2. When the PDSCH indicated from the PDCCH in each CORESET having two different CORESETPoolIndexes completely or partially overlaps, the UE determines the number of actual front loaded DMRS symbols, the actual number of additional DMRS symbols, the actual DMRS symbol location, and the DMRS type of each PDSCH. You can expect them not to be different.

3. The UE can expect that the bandwidth part indicated from the PDCCH in each CORESET having two different CORESETPoolIndex is the same and the subcarrier interval is also the same.

4. The UE can expect that each PDCCH fully includes information on PDSCHs scheduled from PDCCHs in each CORESET having two different CORESETPoolIndex.

[Single-DCI-based Multi-TRP]

As an embodiment of the present disclosure, a single-DCI based multi-TRP transmission method will be described. In the single-DCI-based multi-TRP transmission method, a downlink control channel for NC-JT transmission may be set based on a single-PDCCH.

In the single DCI-based multi-TRP transmission method, PDSCHs transmitted by multiple TRPs can be scheduled with one DCI. At this time, the number of TCI states may be used as a method of indicating the number of TRPs transmitting the corresponding PDSCH. That is, if the number of TCI states indicated in the DCI scheduling the PDSCH is two, it can be regarded as single PDCCH-based NC-JT transmission, and if the number of TCI states is one, it can be regarded as single-TRP transmission. The TCI states indicated by the above DCI can correspond to one or two TCI states among the TCI states activated by MAC-CE. If the TCI states of DCI correspond to the two TCI states activated by MAC-CE, the correspondence between the TCI codepoint indicated by DCI and the TCI states activated by MAC-CE is established, and the MAC corresponding to the TCI codepoint -This may be the case when there are two TCI states activated by CE.

As another example, if at least one codepoint among all codepoints of the TCI state field in DCI indicates two TCI states, the UE can consider that the base station can transmit based on the single-DCI based multi-TRP method. can At this time, at least one codepoint indicating two TCI states in the TCI state field may be activated through Enhanced PDSCH TCI state activation/deactivation MAC-CE.

21 illustrates an example of an enhanced PDSCH TCI state activation/deactivation MAC-CE (enhanced PDSCH TCI state activation/deactivation MAC-CE) structure in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 21 is a diagram illustrating an Enhanced PDSCH TCI state activation/deactivation MAC-CE structure.

The meaning of each field in the corresponding MAC CE and the values that can be set for each field are as follows.

21, if the value of the C ₀ field 2105 is 1, the corresponding MAC-CE may include a TCI state ID _0,2 field 2115 in addition to the TCI state ID _0,1 field 2110. This means that TCI state ID _0,1 and TCI state ID _0,2 are activated for the 0th codepoint of the TCI state field included in DCI, and if the base station instructs the corresponding codepoint to the terminal, the terminal transmits two TCI states. can be instructed. If the value of the C ₀ field 2105 is 0, the corresponding MAC-CE cannot include the TCI state ID _0,2 field 2115, which is the TCI state for the 0th codepoint of the TCI state field included in the DCI. It means that one TCI state corresponding to ID _0,1 is activated.

The above setting may be independent for each cell or each BWP. For example, a PCell may have up to two activated TCI states corresponding to one TCI codepoint, whereas a specific SCell may have up to one activated TCI states corresponding to one TCI codepoint. In this case, while NC-JT transmission is configured in the PCell, it can be considered that NC-JT transmission is not configured in the aforementioned SCell.

[Single-DCI-based Multi-TRP PDSCH repeated transmission scheme (TDM/FDM/SDM) identification method]

Next, the method of distinguishing the single-DCI-based multi-TRP PDSCH repeated transmission scheme is described. The UE may be instructed to use different single-DCI based multi-TRP PDSCH repeated transmission schemes (eg, TDM, FDM, SDM) according to the value indicated by the DCI field and higher layer signaling configuration from the base station. Table 31 below shows a method of distinguishing between single or multiple TRP-based techniques indicated to the terminal according to the value of a specific DCI field and higher layer signaling configuration.

In [Table 42], each column can be explained as follows.

One. Number of TCI states (column 2): This means the number of TCI states indicated by the TCI state field in DCI, and can be one or two.

2. Number of CDM groups (column 3): This means the number of different CDM groups of DMRS ports indicated by the antenna port field in DCI. It can be 1, 2 or 3.

3. RepetitionNumber setting and instruction conditions (column 4): Three conditions may be applied depending on whether repetitionNumber is set for all TDRA entries that can be indicated by the Time Domain Resource Allocation field in DCI and whether the actually indicated TDRA entry has repetitionNumber setting. can

(One) Condition 1: At least one of all TDRA entries that can be indicated by the Time Domain Resource Allocation field includes settings for repetitionNumber, and the TDRA entry indicated by the Time Domain Resource Allocation field in DCI includes settings for repetitionNumber greater than 1 if

(2) Condition 2: When at least one of all TDRA entries that can be indicated by the Time Domain Resource Allocation field includes setting for repetitionNumber, and the TDRA entry indicated by Time Domain Resource Allocation field in DCI does not include setting for repetitionNumber

(3) Condition 3: When all TDRA entries that can be indicated by the Time Domain Resource Allocation field do not include setting for repetitionNumber

4. Related to repetitionScheme setting (column 5): This indicates whether to set repetitionScheme, which is higher layer signaling. RepetitionScheme, which is upper layer signaling, may be set to one of 'tdmSchemeA', 'fdmSchemeA', and 'fdmSchemeB'.

5. Transmission scheme indicated to the UE (column 6): Means single or multiple TRP schemes indicated according to each combination (column 1) represented in Table 31 above.

(One) Single-TRP: This means single TRP-based PDSCH transmission. If the UE has configured the pdsch-AggegationFactor in higher layer signaling PDSCH-config, the UE can be scheduled for repeated single TRP-based PDSCH transmission as many times as configured. Otherwise, the UE may be scheduled for single TRP-based PDSCH transmission.

(2) Single-TRP TDM scheme B: refers to repeated PDSCH transmission based on time resource division between single TRP-based slots. According to Condition 1 related to repetitionNumber described above, the terminal repeatedly transmits the PDSCH in the time dimension as many times as the number of slots of repetitionNumber greater than 1 set in the TDRA entry indicated by the Time Domain Resource Allocation field. At this time, the same start symbol and symbol length of the PDSCH indicated by the TDRA entry are applied to each slot corresponding to the number of repetitionNumber times, and the same TCI state is applied to each repeated transmission of the PDSCH. This technique is similar to the slot aggregation method in that it performs repeated PDSCH transmission between slots on time resources, but is different from slot aggregation in that it can dynamically determine whether or not to indicate repeated transmission based on the Time Domain Resource Allocation field in the DCI. there is.

(3) Multi-TRP SDM: Means a multi-TRP based spatial resource division PDSCH transmission method. This is a method of dividing and receiving layers from each TRP. Although it is not a repetitive transmission method, reliability of PDSCH transmission can be increased in that it can be transmitted by lowering the coding rate by increasing the number of layers. The UE may receive the PDSCH by applying the two TCI states indicated through the TCI state field in the DCI to each of the two CDM groups indicated by the base station.

(4) Multi-TRP FDM scheme A: Multi-TRP-based frequency resource division PDSCH transmission method. It has one PDSCH transmission location, so it is not repetitive transmission like multi-TRP SDM, but it increases the amount of frequency resources and lowers the coding rate. It is a technique that can be transmitted with reliability. Multi-TRP FDM scheme A may apply two TCI states indicated through the TCI state field in DCI to frequency resources that do not overlap each other. If the PRB bundling size is determined to be wideband, the UE applies the first TCI state to the first ceil (N/2) RBs when the number of RBs indicated by the Frequency Domain Resource Allocation field is N, and the remaining floor (N/ 2) RBs apply and receive the second TCI state. Here, ceil(.) and floor(.) are operators that mean rounding up and rounding down to the first decimal place. If the PRB bundling size is determined to be 2 or 4, even-numbered PRGs apply the first TCI state, and odd-numbered PRGs receive the second TCI state.

(5) Multi-TRP FDM scheme B: refers to a multiple TRP-based frequency resource division PDSCH repeated transmission method, and has two PDSCH transmission locations, so that PDSCHs can be repeatedly transmitted to each location. Similarly to A, Multi-TRP FDM scheme B may also apply two TCI states indicated through the TCI state field in DCI to frequency resources that do not overlap with each other. If the PRB bundling size is determined to be wideband, the UE applies the first TCI state to the first ceil (N/2) RBs when the number of RBs indicated by the Frequency Domain Resource Allocation field is N, and the remaining floor (N/ 2) RBs apply and receive the second TCI state. Here, ceil(.) and floor(.) are operators that mean rounding up and rounding down to the first decimal place. If the PRB bundling size is determined to be 2 or 4, even-numbered PRGs apply the first TCI state, and odd-numbered PRGs receive the second TCI state.

(6) Multi-TRP TDM scheme A: Means a repeated PDSCH transmission scheme within a multi-TRP based time resource division slot. The terminal has two PDSCH transmission locations in one slot, and the first reception location may be determined based on the start symbol and symbol length of the PDSCH indicated through the Time Domain Resource Allocation field in DCI. The start symbol of the second reception position of the PDSCH may be a position obtained by applying a symbol offset as much as StartingSymbolOffsetK, which is higher layer signaling, from the last symbol of the first transmission position, and the transmission position may be determined by the indicated symbol length. If the higher layer signaling, StartingSymbolOffsetK, is not set, the symbol offset may be regarded as 0.

(7) Multi-TRP TDM scheme B: Means a repeated PDSCH transmission scheme between multiple TRP-based time resource division slots. The UE has one PDSCH transmission location within one slot, and receives repeated transmission based on the start symbol and symbol length of the same PDSCH during slots as many times as the repetitionNumber times indicated through the Time Domain Resource Allocation field in DCI. can do. If repetitionNumber is 2, the UE may receive repeated PDSCH transmissions of the first and second slots by applying the first and second TCI states, respectively. If repetitionNumber is greater than 2, the terminal may use different TCI state application methods according to which tciMapping, which is higher layer signaling, is set. If tciMapping is set to cyclicMapping, the first and second TCI states are applied to the first and second PDSCH transmission positions, respectively, and the same TCI state application method is applied to the remaining PDSCH transmission positions. If tciMapping is set to sequentialMapping, the first TCI state is applied to the first and second PDSCH transmission positions, and the second TCI state is applied to the third and fourth PDSCH transmission positions. The same applies to the PDSCH transmission position.

[RLM RS related]

Next, the RLM RS selection or determination method when RLM RS (Radio Link Monitoring Reference Signal) is set or not set will be described. The terminal may receive a set of RLM RSs from the base station through RadioLinkMonitoringRS in RadioLinkMonitoringConfig, which is higher layer signaling for each downlink bandwidth part of SpCell, and the specific higher layer signaling structure may follow [Table 43].

The following [Table 44] may indicate the set or selectable number of RLM RSs for each specific purpose according to the maximum number of SSBs (Lmax) per half frame. As shown in Table 33 below, NLR-RLM RSs can be used for link recovery or radio link monitoring according to the Lmax value, and NRLMs among the NLR-RLM RSs can be used for radio link monitoring.

If the UE does not receive higher layer signaling, RadioLinkMonitoringRS, and the UE sets the TCI state for receiving the PDCCH in the control resource set, and at least one CSI-RS is included in the TCI state, the following RLM RS selection method RLM RS can be selected by following them.

- RLM RS selection method 1) If an activated TCI state to be used for PDCCH reception has one reference RS (ie, one activated TCI state has only one of QCL-TypeA, B, or C), UE may select a reference RS of an activated TCI state to be used for PDCCH reception as an RLM RS.

- RLM RS selection method 2) If the activated TCI state to be used for PDCCH reception has two reference RSs (ie, one activated TCI state has one of QCL-TypeA, B, or C and QCL-TypeD ), the UE may select the RLM-RS as the reference RS of QCL-TypeD. The terminal does not expect two QCL-TypeDs to be set in one activated TCI state.)

- RLM RS Selection Method 3) The UE does not expect an aperiodic or semi-persistent RS to be selected as the RLM RS.

- RLM RS Selection Method 4) When Lmax = 4, the UE can select NRLM RSs (since Lmax is 4, two can be selected). The RLM RS is selected based on the RLM RS selection methods 1 to 3, among the reference RSs of the TCI state set in the control resource set for PDCCH reception, and the shorter the period of the search space to which the control resource set is connected, the higher the Based on the priority, the RLM RS is selected from the reference RS of the TCI state set in the control resource set connected to the search space of the shortest cycle. If there are a plurality of control resource sets connected to a plurality of search spaces having the same period, RLM RS selection is performed from the reference RS of the TCI state set to the higher control resource set index.

22 illustrates an example of an RLM RS selection process in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 22 is a diagram illustrating an RLM RS selection process according to an embodiment of the present disclosure.

22 shows control resource set #1 to control resource set #3 (2205 to 2207) connected to search spaces #1 to search space #4 (2201 to 2204) having different cycles within an activated downlink bandwidth part; The reference RS of the TCI state set in each control resource set is shown. Based on the RLM RS selection method 4, RLM RS selection uses the TCI state set in the control resource set connected to the search space of the shortest period, but the periods of search space #1 (2201) and search space #3 (2203) is the same, among control resource set #1 (2205) and control resource set #2 (2206) connected to each search space, the reference RS of the TCI state set in control resource set #2 having the highest index is the most suitable for RLM RS selection. It can be used as a high priority. In addition, since the TCI state set in control resource set #2 has only QCL-TypeA and the corresponding reference RS is a periodic RS, PC CSI-RS #2 2210 is the most First, it can be selected as RLM RS. Next, the reference RS of QCL-TypeD can be a selection candidate by the RLM RS selection method 2 among the reference RSs of the TCI state set in the control resource set #1 having priority, but the corresponding RS is semi-persistent Since it is an RS (2209), it is not selected as an RLM RS by the RLM RS selection method 3 above. Therefore, reference RSs of TCI state set in control resource set #3 can be considered as the next priority, and by the RLM RS selection method 2, the reference RS of QCL-TypeD can be a selection candidate, and the reference RS can be selected periodically. Since it is a (periodic) RS, P CSI-RS#4 2212 can be selected as the second RLM RS by the RLM RS selection method 3 above. Accordingly, the finally selected RLM RSs may be P CSI-RS#2 or P CSI-RS#4 (2213).

Referring to the descriptions related to PDCCH transmission/reception configuration and transmission beam configuration described above, since repeated PDCCH transmission is not currently supported in Rel-15/16 NR, it may be difficult to achieve required reliability in a scenario requiring high reliability such as URLLC. Meanwhile, in Rel-17 FeMIMO, a method of improving reception reliability of a PDCCH through repeated transmission of the PDCCH is being standardized. As a method of repetitive transmission of a PDCCH, a non-SFN scheme in which time or frequency resources are separated and repeatedly transmitted through different TRPs for control resource sets connected to each of a plurality of search spaces that are typically explicitly connected by higher layer signaling, and 1 There may be a method of setting a plurality of TCI states in the number of control resource sets and repeatedly transmitting them in the SFN method. Among them, for the non-SFN scheme, different control resource sets may be connected to a plurality of search spaces explicitly connected by higher layer signaling, or the same control resource set may be connected to all search spaces. At this time, a method in which different control resource sets are connected to each other can be considered as a multiple TRP-based PDCCH repeated transmission method by considering that each control resource set is transmitted in a different TRP. In addition, at this time, a method in which the same control resource set is connected to all search spaces can be considered as a single TRP-based repeated PDCCH transmission method by considering that all of them are transmitted in the same TRP.

Meanwhile, in the current Rel-15/16 NR, the UE receives upper layer configuration information about the TCI state for the PDCCH and PDSCH and receives the MAC-CE indicating activation of the corresponding TCI state. Receive PDCCH and PDSCH In this case, the operation of which default beam is to be received is defined. However, the above-described basic beam operations of the PDCCH and PDSCH may need to be redefined as SFN transmission for the PDCCH and PDSCH is introduced. Regarding the PDSCH, the UE may dynamically switch reception of a single TRP-based PDSCH transmission and multiple TRP-based SFN PDSCH transmissions through a capability report of the UE. That is, scheduling may be dynamically performed for a single TRP-based PDSCH transmission and multiple TRP-based SFN PDSCH transmissions through DCI. Conversely, if the terminal does not report the corresponding terminal capability and receives higher layer signaling for multi-TRP based SFN PDSCH transmission, the terminal may be able to receive only the SFN PDSCH transmission. Therefore, in a specific situation, the terminal can receive only SFN transmission. In this way, when only SFN transmission for PDCCH and PDSCH can be received at a specific time point, additional definition may be required for basic beam operations of PDCCH and PDSCH depending on when the corresponding time point is. In the present invention, when a point in time of a terminal capable of receiving only SFN transmission is after receiving higher layer signaling, basic beam operations of the PDCCH and the PDSCH are described in detail.

For convenience in the following description of the present disclosure, cells, transmission points, panels, beams, or transmission points that can be distinguished through higher layer/L1 parameters such as TCI state or spatial relation information or indicators such as cell ID, TRP ID, or panel ID / and the transmission direction are unified and described as a transmission reception point (TRP). Therefore, in actual application, TRP can be appropriately replaced with one of the above terms.

Hereinafter, in the present disclosure, in determining whether cooperative communication is applied, a PDCCH (s) allocated to a PDSCH to which cooperative communication is applied has a specific format, or a PDCCH (s) allocated to a PDSCH to which cooperative communication is applied is cooperative. Include a specific indicator indicating whether or not communication is applied, or PDCCH(s) allocating a PDSCH to which cooperative communication is applied are scrambled with a specific RNTI, or cooperative communication is assumed in a specific interval indicated by a higher layer, etc. It is possible to use various methods. For convenience of explanation, the terminal receiving the PDSCH to which cooperative communication is applied based on conditions similar to the above will be referred to as an NC-JT case.

Hereinafter, embodiments of the present disclosure will be described in detail with accompanying drawings. Hereinafter, a base station is a subject that performs resource allocation of a terminal, and may be at least one of a gNode B, a gNB, an eNode B, a Node B, a base station (BS), a radio access unit, a base station controller, or a node on a network. The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing communication functions. Hereinafter, an embodiment of the present disclosure is described using a 5G system as an example, but the embodiment of the present disclosure can be applied to other communication systems having a similar technical background or channel type. For example, LTE or LTE-A mobile communication and mobile communication technology developed after 5G may be included in this. Accordingly, the embodiments of the present disclosure may be applied to other communication systems through some modification without significantly departing from the scope of the present disclosure as determined by a person skilled in the art. The contents of this disclosure are applicable to FDD and TDD systems.

In addition, in describing the present disclosure, if it is determined that a detailed description of a related function or configuration may unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present disclosure, which may vary according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout this specification.

Hereinafter, in describing the present disclosure, higher layer signaling may be signaling corresponding to at least one or a combination of one or more of the following signaling.

- MIB (Master Information Block)

- SIB (System Information Block) or SIB X (X=1, 2, ??)

- Radio Resource Control (RRC)

- MAC (Medium Access Control) CE (Control Element)

Also, L1 signaling may be signaling corresponding to at least one or a combination of one or more of signaling methods using the following physical layer channels or signaling.

- PDCCH (Physical Downlink Control Channel)

- Downlink Control Information (DCI)

- UE-specific DCI

- Group common DCI

- Common DCI

- Scheduling DCI (eg DCI used for the purpose of scheduling downlink or uplink data)

- Non-scheduling DCI (eg, a DCI that is not intended to schedule downlink or uplink data)

- PUCCH (Physical Uplink Control Channel)

- UCI (Uplink Control Information)

Hereinafter, in the present disclosure, determining the priority between A and B means selecting a higher priority according to a predetermined priority rule and performing a corresponding operation or lower priority. It may be variously referred to as omitting or dropping an operation for.

Hereinafter, in the present disclosure, the above examples are described through a plurality of embodiments, but they are not independent, and one or more embodiments may be applied simultaneously or in combination.

<First Embodiment: Multiple TRP-based PDCCH Repeated Transmission Method>

As an example of an embodiment of the present disclosure, a PDCCH repetition transmission method considering multiple TRPs will be described. Repetitive PDCCH transmission considering multiple TRPs may have various methods depending on how to apply each TCI state to be applied when transmitting the PDCCH in each TRP to the above-described various parameters used for PDCCH transmission. For example, various parameters used for PDCCH transmission to which different TCI states are applied may include CCE, PDCCH candidate group, control resource set, search space, and the like. In repeated PDCCH transmissions considering multiple TRPs, soft combining, selection, and the like may be considered as a reception method of the UE.

The following five methods may exist for repeated PDCCH transmission through multiple TRPs, and the base station configures at least one of the five methods to the UE through higher layer signaling, instructs the UE through L1 signaling, or transmits at least one of the five methods to the UE through higher layer signaling It can be set and instructed by a combination of L1 signaling.

[Method 1-1] Method of repeatedly transmitting a plurality of PDCCHs having the same payload

Method 1-1 is a method of repeatedly transmitting a plurality of pieces of control information having the same DCI format and payload. Each of the above-described control information may indicate information for scheduling repeatedly transmitted PDSCHs, for example, {PDSCH#1, PDSCH#2, ..., PDSCH#Y} repeatedly transmitted over a plurality of slots. The fact that the payload of each control information that is repeatedly transmitted is the same means that the PDSCH scheduling information of each control information, such as the number of repeated PDSCH transmissions, the time axis PDSCH resource allocation information, that is, the slot offset (K_0) between the control information and PDSCH#1 and the PDSCH It can be expressed that the number of symbols, frequency axis PDSCH resource allocation information, DMRS port allocation information, PDSCH-to-HARQ-ACK timing, PUCCH resource indicator, etc. are all the same. The terminal can improve reception reliability of control information by soft combining repetitive transmission control information having the same payload.

For the above soft combine, the terminal needs to know in advance the resource location and the number of repeated transmissions of control information to be repeatedly transmitted. To this end, the base station may indicate in advance resource configurations of the time domain, frequency domain, and spatial domain of the above-described repeated transmission control information. When control information is repeatedly transmitted on the time axis, control information is repeatedly transmitted over different CORESETs, or repeatedly transmitted over different search space sets within one CORESET, or different PDCCH monitoring occasions within one CORESET and one search space set. It can be repeatedly transmitted over. Units of repetitively transmitted resources (CORESET units, search space set units, PDCCH monitoring occasion units) and locations of repetitive transmission resources (PDCCH candidate index, etc.) on the time axis may be indicated through higher layer settings of the base station. At this time, the number of repeated transmissions of the PDCCH and/or the list and transmission pattern of TRPs participating in repeated transmissions may be explicitly indicated, and higher layer indication or MAC-CE/L1 signaling may be used as an explicit indication method. . At this time, the list of TRPs may be indicated in the form of the TCI state or the aforementioned QCL assumption.

When control information is repeatedly transmitted in the frequency axis, the control information may be repeatedly transmitted over different CORESETs, repeatedly transmitted over different PDCCH candidates within one CORESET, or repeatedly transmitted for each CCE. A unit of repetitively transmitted resources and a location of repetitive transmission resources on the frequency axis may be indicated through higher layer settings of the base station. In addition, the number of repeated transmissions and/or the list of TRPs participating in repeated transmissions and transmission patterns may be explicitly indicated, and higher layer indication or MAC-CE/L1 signaling may be used as an explicit indication method. At this time, the list of TRPs may be indicated in the form of the TCI state or the aforementioned QCL assumption.

When control information is repeatedly transmitted along the spatial axis, the control information can be repeatedly transmitted over different CORESETs or by setting two or more TCI states in one CORESET.

According to an embodiment of the present disclosure, a method of repeatedly transmitting a PDCCH by a base station will be described. In a wireless communication system, DCI including scheduling information for PUSCH or PDSCH may be transmitted from a base station to a terminal through a PDCCH.

23 illustrates an example of a process of generating a PDCCH repeatedly transmitted through two TRPs in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 23 is a diagram illustrating a process of generating a PDCCH repeatedly transmitted through two TRPs according to an embodiment of the present disclosure.

The base station generates DCI (2350), attaches the CRC to the DCI payload (2351), goes through channel coding (2352), scrambling (2353) and modulation (2354) to generate the PDCCH. can be (2355). Thereafter, the base station may copy the generated PDCCH a plurality of times (2356, 2357, 2358) and transmit it using a specific resource (eg, time, frequency, transmission beam, etc.) (2359). That is, all coded bits for the PDCCH repeatedly transmitted in each TRP may be the same. In this way, in order to have the same coded bits, the information value for each DCI field in the PDCCH may also be set to be the same. For example, all fields (TDRA, FDRA, TCI, antenna ports, ??) included in DCI information may be set to have the same value. Here, the same value may generally be interpreted as one meaning, but may be interpreted as a plurality of meanings when it includes or corresponds to a plurality (eg, two) values as described above by a special setting. A detailed description related to this will be described below.

For example, as shown in FIG. 23, if the base station repeatedly transmits the PDCCH twice (eg, m = 2), the base station maps the PDCCHs to TRP A and TRP B, respectively, in the spatial domain. On the side, the PDCCH may be repeatedly transmitted based on the same or different beams. At this time, if PDCCH repetition transmission can be performed based on CORESETs respectively connected to two search spaces explicitly connected to each other by higher layer signaling, and the IDs of the CORESETs connected to the search spaces are the same or the TCI state of the CORESETs is the same. , repeated PDCCH transmission can be performed based on a single TRP, and repeated PDCCH transmission can be performed based on multiple TRPs when IDs of CORESETs connected to the search space are all different or TCI states of CORESETs are all different. If the base station repeatedly transmits the PDCCH four times, the base station maps two PDCCHs to TRP A and TRP B, respectively, and in this case, the two PDCCHs of each TRP can be transmitted separately in the time domain. The repeated PDCCH transmissions classified in the time domain can be repeated in a slot based, subslot based, or mini-slot based time unit.

However, the above method is only an example and is not limited thereto. In the present disclosure, the terminal and the base station may consider the following method for the PDCCH repetition operation described above.

- PDCCH repetition in terms of time/frequency/spatial domain within the same CORESET and within the same slot.

- PDCCH repetition in terms of time/frequency/spatial domain between different slots within the same CORESET.

- PDCCH repetition in terms of time/frequency/spatial domain within the same slot between different CORESETs.

- PDCCH repetition in terms of time/frequency/spatial domain between different CORESETs and between different slots.

In addition, when CORESETPoolindex is set, each CORESETPoolindex can be considered in addition to the CORESET described above. Also, the number of repetitions of the PDCCH may be independently increased, and accordingly, the above-described methods may be considered in combination at the same time.

The base station may preset information on which domain the PDCCH is repeatedly transmitted in the terminal through an RRC message. For example, in the case of repeated PDCCH transmission in the time domain, the base station selects any one of the above-described slot based, subslot based, or mini-slot based time units. Information about whether one is repeated can be set in advance in the terminal. In the case of repeated PDCCH transmission in the frequency domain, the base station may pre-configure information on repetition based on any one of CORESET, bandwidth part (BWP), or component carrier (CC) in the terminal. In the case of repeated PDCCH transmission in terms of the spatial domain, the base station may preset information related to a beam for repeated PDCCH transmission in the terminal through configuration for each QCL type. Alternatively, the information listed above may be combined and transmitted to the terminal through an RRC message. Therefore, the base station can repeatedly transmit the PDCCH according to preset information through the RRC message, and the terminal can repeatedly receive the PDCCH according to preset information through the RRC message.

[Method 1-2] Method of repeatedly transmitting a plurality of control information that may have different DCI formats and/or payloads

Method 1-2 is a method of repeatedly transmitting a plurality of pieces of control information that may have different DCI formats and/or payloads. These control information schedules repeated PDSCH transmissions, and the number of repeated PDSCH transmissions indicated by each control information may be different. For example, PDCCH#1 indicates information for scheduling {PDSCH#1, PDSCH#2, ..., PDSCH#Y}, whereas PDCCH#2 indicates {PDSCH#2, ..., PDSCH#Y} Indicates scheduling information, ... , PDCCH#X may indicate information for scheduling {PDSCH Y}. This method of repeatedly transmitting control information has the advantage of reducing the total delay time required for repeated transmission of control information and PDSCH compared to Method 1-1. On the other hand, since the payload of each repeatedly transmitted control information may be different in this method, soft combining of the repeatedly transmitted control information may not be possible, and thus reliability may be lower than method 1-1.

In the above method 1-2, the terminal may not need to know in advance the resource location and number of repeated transmissions of control information to be repeatedly transmitted, and the terminal can independently decode and process each of the repeatedly transmitted control information. If the UE decodes a plurality of repetitive transmission control information scheduling the same PDSCH, only the first repetitive transmission control information can be processed and second and subsequent repetitive transmission control information can be ignored. Alternatively, the resource location and the number of repeated transmissions of control information to be repeatedly transmitted may be indicated in advance, and the indication method may be the same as the method described in method 1 above.

[Method 1-3] Method of repeatedly transmitting a plurality of pieces of control information that may have different DCI formats and/or payloads

Method 1-3 is a method of repeatedly transmitting a plurality of pieces of control information, each of which may have a different DCI format and/or payload. At this time, each control information repeatedly transmitted has the same DCI format and payload. Since the plurality of control information in Method 1-2 cannot be soft-combined, reliability may be lower than that of Method 1-1. this can be long Method 1-3 is a method using the advantages of Methods 1-1 and 1-2, and the total delay time required for repeated transmission of control information and PDSCH is reduced compared to Method 1-1 and is higher than Method 1-2. Control information can be transmitted with reliability.

In Method 1-3, soft combine of Method 1-1 and individual decoding of Method 1-2 may be used to decode and soft combine the repeatedly transmitted control information. For example, among repeated transmissions of a plurality of pieces of control information that may have different DCI formats and/or payloads, firstly transmitted control information is decoded as in Method 1-2 and repeated transmissions of the decoded control information are performed. Soft combining can be performed as in Method 1-1 above.

Meanwhile, the base station may select and configure one of the method 1-1, method 1-2, or method 1-3 for repeated transmission of control information. The repeated control information transmission scheme may be explicitly instructed by the base station to the terminal through higher layer signaling. Alternatively, the control information repetition transmission method may be indicated in combination with other setting information. For example, a higher layer configuration indicating a repeated PDSCH transmission scheme may be combined with an instruction for repeating control information transmission. When the PDSCH is instructed to be repeatedly transmitted using the FDM method, it can be interpreted that the control information is repeatedly transmitted only in the method 1-1. For this reason, the delay time reduction effect according to the method 1-2 is not effective for the repeated PDSCH transmission in the FDM method. because there is no For a similar reason, when the PDSCH is instructed to be repeatedly transmitted in an intra-slot TDM scheme, it can be interpreted that the control information is repeatedly transmitted according to Method 1-1. On the other hand, when the PDSCH is instructed to be repeatedly transmitted in an inter-slot TDM scheme, the above method 1-1, method 1-2 or method 1-3 for repeated transmission of control information is performed through higher layer signaling or L1 signaling can be selected through

On the other hand, the base station may explicitly instruct the terminal to transmit control information repeatedly through settings such as an upper layer. Alternatively, the control information repetition transmission unit may be indicated in combination with other setting information. For example, a higher layer configuration indicating a repeated PDSCH transmission scheme may be combined with the control information repetition transmission unit. If the PDSCH is instructed to be repeatedly transmitted using the FDM method, it can be interpreted that the control information is repeatedly transmitted using the FDM or SDM method. This is because there is no effect of reducing delay time due to repeated PDSCH transmission. For a similar reason, when the PDSCH is instructed to be repeatedly transmitted in an intra-slot TDM scheme, the control information may be interpreted as being repeatedly transmitted in intra-slot TDM, FDM, or SDM. On the other hand, when the PDSCH is instructed to be repeatedly transmitted in TDM between multiple slots, it can be selected through higher layer signaling so that control information can be repeatedly transmitted through TDM between multiple slots, TDM within a slot, FDM or SDM.

[Method 1-4] PDCCH transmission method for applying each TCI state to different CCEs in the same PDCCH candidate group

Methods 1-4 may transmit different TCI states meaning transmission from multiple TRPs by applying different CCEs in the PDCCH candidate group to improve PDCCH reception performance without repeated PDCCH transmission. This method is not a repetitive transmission of the PDCCH, but since different CCEs in the PDCCH candidate group are transmitted by applying different TCI states in each TRP, it can be a method of obtaining spatial diversity within the PDCCH candidate group. Different CCEs to which different TCI states are applied can be separated in a time or frequency dimension, and it is necessary for the terminal to know in advance the location of resources to which different TCI states are applied. The UE may receive different CCEs to which different TCI states are applied within the same PDCCH candidate group and independently decode or decode at once.

[Method 1-5] PDCCH transmission method (SFN method) that applies a plurality of TCI states to all CCEs in the same PDCCH candidate group

Method 1-5 may apply a plurality of TCI states to all CCEs in the PDCCH candidate group and transmit the SFN method in order to improve PDCCH reception performance without repeated PDCCH transmission. Although this method is not PDCCH repetitive transmission, it may be a method of obtaining spatial diversity through SFN transmission at the same CCE location within the PDCCH candidate group. The UE may receive CCEs at the same location to which different TCI states are applied within the same PDCCH candidate group and independently decode or decode at once using some or all of the plurality of TCI states.

<Second Embodiment: Reporting UE Capability Related to Soft Combining When Repetitively Transmitting PDCCH>

The UE may report UE capabilities related to soft combining to the BS when repeatedly transmitting the PDCCH, and there may be several methods for this. Specific methods may be as follows.

[UE Capability Reporting Method 1] The UE may report only whether or not soft combining is possible when repeatedly transmitting a PDCCH to the base station as UE capability in the form of enabling or disabling.

For example, if the terminal reports information that soft combining is possible during repeated PDCCH transmission to the base station as a terminal capability, the base station determines whether the soft combining of the terminal is possible to the most flexible degree (for example, the terminal is at the LLR level It is determined that soft combining is possible), and the setting related to repeated PDCCH transmission can be notified to the UE with maximum flexibility when setting the PDCCH transmission. At this time, as an example related to PDCCH repetition configuration, the base station performs soft combining between control resource sets or search spaces in which the terminal has different configurations, soft combining between PDCCH candidates within the same aggregation level, or different aggregation Assuming that soft combining between PDCCH candidates between levels is possible, the corresponding setting may be notified to the UE.

As another example, if the terminal reports information that soft combining is possible during repeated PDCCH transmission to the base station as a terminal capability, the base station most conservatively determines the level of soft combining that the terminal can perform (e.g., the terminal It is determined that soft combining is possible at the OFDM symbol level), and the PDCCH repetitive transmission-related setting can be notified to the UE in the most restrictive manner when setting the PDCCH transmission. At this time, as an example related to PDCCH repetition configuration, the base station assumes that the terminal can perform soft combining between a plurality of control resource sets having the same configuration or soft combining between PDCCH candidates between the same aggregation levels, and performs the configuration for the terminal. may be notified.

[UE Capability Reporting Method 2] Compared to the above-described UE capability reporting method 1, in order to express the operation of soft combining possible in the UE as a UE capability in more detail, the UE determines the possible degree of soft combining when repeatedly transmitting a PDCCH to the base station. Levels can be divided and reported as terminal capabilities. That is, among each signal level generated from the reception operation process of the terminal, the terminal checks the signal level to which soft combining can be applied to repeated PDCCH transmissions, and the terminal can report such information to the base station as a terminal capability. there is. For example, as a signal level to which soft combining can be applied, the terminal can inform that soft combining is possible at the OFDM symbol level, can inform that soft combining is possible at the modulation symbol level, and soft combine at the LLR level. It can tell you that innings are possible. According to each signal level reported by the terminal, the base station may notify an appropriate setting so that the terminal can perform soft combining according to the reported terminal capability.

[UE Capability Reporting Method 3] When the UE repeatedly transmits a PDCCH to the base station, the UE may transmit necessary constraints to enable soft combining as UE capabilities. For example, the terminal may report to the base station that the configuration of each control resource set including two repeated PDCCHs should be the same. As another example, the terminal may report to the base station that the two repeated PDCCH candidates should have at least the same aggregation level.

[UE Capability Reporting Method 4] When the UE receives repeated PDCCH transmission from the base station, it can report which PDCCH repeated transmission scheme is supported through UE capability. As an example, the terminal may report to the base station that the method 1-5 (SFN transmission method) is supported. As another example, the terminal may report to the base station that intra-slot TDM, inter-slot TDM, or FDM scheme among method 1-1 (a method of repeatedly transmitting a plurality of PDCCHs having the same payload) is supported. In particular, in the case of TDM, the terminal may report the maximum value of the time interval between two repeated PDCCHs to the base station. For example, if the terminal reports the maximum value of the time interval between two repeated PDCCHs as 4 OFDM symbols, the base station determines the time interval between the two repeated PDCCHs when performing TDM-based repeated PDCCH transmission to the terminal based on the information. It may need to be adjusted to less than 4 OFDM symbols.

[UE Capability Reporting Method 5] When receiving repeated PDCCH transmissions from the base station, the terminal may report the number of times of blind decoding consumed to the base station as the terminal capability. For example, the terminal sets the number of blind decoding consumed when receiving repeated PDCCH transmissions to 1, 2, or 3 is reported to the base station, and the base station assumes that the terminal consumes as much as the reported number of blind decoding when receiving repeated PDCCH transmissions, and the search space so as not to exceed the maximum number of blind decoding times that the terminal can use within a slot or span. And settings related to the control resource set may be delivered to the terminal.

The above-described UE capability reporting methods may be configured in a combination of two or more when actually applied. For example, the UE reports that soft combining is possible at the LLR level by [UE capability reporting method 2], and at the same time reports that two repeated PDCCH candidates must have at least the same aggregation level by [UE capability reporting method 3] and supports repeated TDM PDCCH transmission by [UE capability reporting method 4], but the maximum value of the time interval between two repeated PDCCHs can be reported as 4 OFDM symbols. In addition, applications based on combinations of various UE capability reporting methods are possible, but detailed descriptions will be omitted.

<Third Embodiment: Repeated PDCCH Transmission and Explicit Connectivity Related Setting Method>

As an example of an embodiment of the present disclosure, a method for configuring repeated PDCCH transmissions to enable soft combining during repeated PDCCH transmissions will be described. When the base station performs repeated PDCCH transmission to the UE based on Method 1-1 (a method of repeatedly transmitting multiple PDCCHs having the same payload) among various repetitive PDCCH transmission methods, whether or not soft combining of the UE is possible is determined. In order to reduce the number of times of blind decoding, information indicating that there is an explicit connection (linkage or association) between repeated PDCCH candidates is set by higher layer signaling, indicated by L1 signaling, or a combination of higher layer signaling or L1 signaling. can be set up and instructed. More specifically, various connection methods may exist as follows.

There may be various methods as follows for configuring repeated PDCCH transmission and explicit connectivity through higher layer signaling.

[PDCCH repetition configuration method 1] When configuration information exists in higher layer signaling PDCCH-config

The base station may configure PDCCH-repetition-config in PDCCH-config, which is higher layer signaling, for repeated PDCCH transmission and explicit connectivity-related configuration to the terminal, and PDCCH-repetition-config may include the following information.

One. PDCCH repetitive transmission method -One of TDM, FDM, and SFN

2. Control resource set-search space combination(s) to be used in repeated PDCCH transmissions

(One) Control resource set index(es) - OPTIONAL

(2) Searchspace index(es) - OPTIONAL

3. Aggregation level(s) for explicit connectivity - OPTIONAL

4. PDCCH Candidate Index(s) for Explicit Connectivity - OPTIONAL

5. Frequency resources for explicit connectivity - OPTIONAL

Based on the above information, the base station may configure repeated PDCCH transmission to the terminal through higher layer signaling. For example, if the PDCCH repetitive transmission scheme is set to SFN, the control resource set index is set to 1 as a control resource set-search space combination to be used for repeated PDCCH transmission, and the search space index is not set, the terminal selects index 1 It can be expected that the PDCCH will be repeatedly transmitted through the method 1-5 (SFN transmission method) in the control resource set. At this time, the set control resource set is configured with one or a plurality of different TCI states by higher layer signaling, instructed by L1 signaling or MAC-CE signaling, or a combination of higher layer signaling and L1 signaling or MAC-CE signaling. can be set up and instructed. In addition, if the repeated PDCCH transmission scheme is set to SFN, the UE may not expect a search space index to be set within a control resource set-search space combination to be used during repeated PDCCH transmissions. As another example, the repeated PDCCH transmission method is set to TDM or FDM, a total of 2 control resource set-search space combinations to be used for repeated PDCCH transmissions are set, and for the first combination, a control resource set index of 1 and a search space index are If the control resource set index 2 and the search space index are set to 2 for the 1 and 2 combinations, the terminal uses the two control resource set-search space combinations and repeats the PDCCH in the TDM or FDM method through the above method 1-1. can be expected to be transmitted. At this time, each configured control resource set receives a plurality of TCI states that are the same or different from each other by higher layer signaling, or instructed by L1 signaling or MAC-CE signaling, or a combination of higher layer signaling, L1 signaling, or MAC-CE signaling. can be set and instructed. In addition, if the PDCCH repetitive transmission method is set to TDM or FDM, the UE can expect to set up to two control resource set-search space combinations to be used for repeated PDCCH transmission, and control resource set and search space combinations within each combination. You can expect all indexes to be set.

In addition, the values of the above 5 pieces of information can be updated without RRC resetting based on MAC-CE. If the base station does not configure PDCCH-repetition-config for the terminal, the terminal does not expect repeated transmission of the PDCCH, but can expect only single transmission of the PDCCH. All or at least one of the aggregation level, PDCCH candidate index, and frequency resources for the above-described explicit connectivity may be configured according to an explicit connectivity method described later.

[PDCCH repetition configuration method 2] When configuration information exists in higher layer signaling for search space

For repeated PDCCH transmission, the base station may add higher layer signaling to the searchSpace, which is higher layer signaling for the search space, and notify the UE. For example, a parameter called repetition, which is additional higher layer signaling, may be set to on or off in searchSpace, which is higher layer signaling, so that the corresponding search space is used for repetitive transmission. Search spaces for which Repetition is set to on may be one or two per bandwidth part. For example, if searchSpaceId is set to 1, controlResourceSetId is set to 1, and repetition is set to on in searchSpace, which is higher layer signaling for search space index 1, the terminal performs the above in control resource set 1 connected to search space 1. It can be expected that PDCCH repeated transmission is performed according to method 1-5 (SFN transmission method). As another example, searchSpaceId is set to 1 in searchSpace, which is higher layer signaling for search space index 1, controlResourceSetId is set to 1, repetition is set to on, and in searchSpace, which is higher layer signaling for search space index 2, If searchSpaceId is set to 2, controlResourceSetId is set to 2, and repetition is set to on, the terminal performs the method 1-1 between the combination of control resource set 1 + search space 1 and control resource set 2 + search space 2. It can be seen that repeated PDCCH transmission is performed by TDM or FDM using TDM and FDM can be distinguished according to time and frequency settings through higher layer signaling of control resource sets 1 and 2 and search spaces 1 and 2. In addition, within higher layer signaling for a search space in which repetition is set to on, aggregation levels or PDCCH candidate indexes for explicit connectivity specified in [PDCCH repetition setting method 1] may be set, and an explicit connection method to be described later So neither can be set, either can be set, or both can be set.

<Fourth Embodiment: PDSCH SFN Transmission Method Based on Multiple TRPs>

As an example of an embodiment of the present disclosure, a method for indicating and setting through a combination of L1 signaling and higher layer signaling for multiple TRP-based PDSCH SFN transmission in a base station and a reception method in a terminal will be described. When the base station schedules the multi-TPSCH SFN transmission method to the terminal through DCI, the conditions of the DCI field and higher layer signaling may be as follows.

- TCI state field in DCI: may indicate a codepoint of a TCI state field including two TCI states.

- Antenna port field in DCI: The number of CDM groups may be fixed to one, or may be one or more.

- Time Domain Resource Allocation field in DCI: There may be no restrictions on the field (for example, one of conditions 1, 2, or 3 for the Time Domain Resource Allocation field described in Table 31 above may be possible). , Only condition 3 described above (eg, when all TDRA entries do not set repetitionNumber, which is upper layer signaling), may be possible.

- Higher layer signaling repetitionScheme: may or may not be set.

- New higher layer signaling for the multi-TRP based PDSCH SFN scheme may be additionally configured. Meanwhile, in order to support the above-described multi-TRP based PDSCH scheme (eg, multi-TRP SDM, FDM scheme A, FDM scheme B, TDM scheme A, TDM scheme B), the UE is required to use a new multi-TRP based PDSCH SFN scheme. Higher layer signaling can be expected not to be configured.

24 illustrates an example of a multi-TRP based PDSCH SFN transmission method in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 24 is a diagram illustrating a multi-TRP based PDSCH SFN transmission method according to an embodiment of the present disclosure.

The base station instructs and configures the value of the above-described DCI field and higher layer signaling to the terminal, and then transmits the PDCCH to the terminal (2400). TCI states #1 and #2 may be indicated through the TCI state field in the corresponding PDCCH, and time and frequency resource allocation information may be indicated through one Time Domain Resource Allocation field and one Frequency Domain Resource Allocation field, respectively. The terminal may receive the PDSCH transmitted through SFN using two different TCI states (TCI states #1 and #2) at a resource location based on the corresponding time and frequency resource allocation information (2401, 2402). This can be equally applied to repetitive transmission of the SFN-based PDCCH. The UE may receive the SFN transmitted PDCCH by applying two different TCI states within one control resource set (2450, 2451). Based on the DCI field information included in the PDCCH transmitted by the SFN, the UE transmits the SFN using two different TCI states (TCI states #1 and #2) at a resource location based on the corresponding time and frequency resource allocation information. PDSCH can be received (2452, 2453).

<Embodiment 4-1: Multiple TRP-based SFN PDCCH and SFN PDSCH Transmission Method Signaling or Constraints>

As an example of an embodiment of the present disclosure, an instruction and setting method or constraints through a combination of L1 signaling and higher layer signaling for a multi-TRP based SFN PDCCH and SFN PDSCH transmission method in a base station will be described.

The terminal transmits SFN of the base station through higher layer signaling from the base station through base station-based Doppler correction (hereinafter, it can be named as base station-based SFN method) or the base station's SFN transmission method through terminal-based Doppler correction (hereinafter referred to as terminal-based SFN method). can be named according to the method.), one SFN transmission method of the base station can be set. The corresponding setting may be set for each bandwidth part or each carrier. In addition, the configuration may use each configuration information for the PDCCH and the PDSCH, or may use one common configuration information for the PDCCH and the PDSCH. The UE may not expect that different schemes are applied to PDCCH and PDSCH for the type of SFN transmission scheme of the base station. That is, when the SFN transmission scheme of the base station is applied to transmission of the PDCCH and PDSCH from the base station, the terminal can expect that the same SFN transmission scheme is applied to the PDCCH and the PDSCH. In addition, when the base station's SFN transmission scheme is applied to PDCCH transmission from the base station, the terminal can expect the same SFN transmission scheme to be configured and applied to all control resource sets. That is, it may not be expected that the base station-based SFN scheme is configured and applied to some control resource sets and the terminal-based SFN scheme is applied to the remaining control resource sets.

The terminal may transmit to the base station whether the base station can dynamically change the reception operation for single TRP-based PDSCH transmission or SFN PDSCH transmission by reporting the terminal capability. The UE capability report may be reported for each carrier or for each UE. For a terminal that does not report the corresponding terminal capability, the base station may transmit the Enhanced PDSCH TCI state activation/deactivation MAC-CE to the terminal so that all codepoints in the TCI field in the DCI indicate two TCI states. That is, the terminal may not expect that at least one codepoint of the TCI field in the DCI indicates one TCI state when the corresponding terminal capability is not reported. For the UE reporting the corresponding UE capability, the base station may set whether or not to dynamically change the reception operation for single TRP-based PDSCH transmission or multiple TRP-based PDSCH SFN transmission through higher layer signaling, and the UE configures the corresponding higher layer signaling Depending on whether or not, one or two TCI states may be indicated through the TCI field in the DCI. In addition, for a terminal that reports or does not report the corresponding terminal capability, higher layer signaling regarding whether or not the reception operation for single TRP-based PDSCH transmission or multiple TRP-based PDSCH SFN transmission can be dynamically changed may not exist, and the base station can indicate one or two TCI states through the TCI field in the DCI using the TCI state activation MAC-CE for the PDSCH for the UE reporting the corresponding UE capability, and for the UE that has not reported the corresponding UE capability, For PDSCH, it is possible to indicate that all TCI codepoints have one TCI state or all TCI codepoints have two TCI states through the TCI field in DCI using TCI state activation MAC-CE for PDSCH.

The terminal may transmit to the base station whether the base station can dynamically change the reception operation for single TRP-based PDCCH transmission or SFN PDCCH transmission by reporting the terminal capability. The UE capability report may be reported for each carrier or for each UE. For a terminal that does not report the corresponding terminal capability, the base station may configure upper layer signaling for the coexistence of a control resource set in which one TCI state is activated and a control resource set in which two TCI states are activated, to the terminal. Corresponding higher layer signaling may be set for each bandwidth part or for each carrier. If the terminal does not report the terminal capability, the corresponding configuration information from the base station may not be set, or it may be set so that coexistence of control resource sets in which different numbers of TCI states are activated is impossible, and if the terminal reports the terminal capability, the base station Corresponding configuration information from can be set to enable coexistence of control resource sets in which different numbers of TCI states are activated. In addition, for the terminal reporting the corresponding terminal capability, higher layer signaling regarding the coexistence of control resource sets in which different numbers of TCI states are activated may not exist, and the base station reports the corresponding terminal capability In order for control resource sets with different numbers of activated TCI states to coexist, some control resource sets have one TCI and the remaining control resource sets have two TCI states through TCI state activation MAC-CE for the PDCCH. All control resource sets have one TCI through TCI state activation MAC-CE for PDCCH so that control resource sets in which different numbers of TCI states are activated do not coexist for a terminal that can be activated and has not reported the corresponding terminal capability. state, or all control resource sets can be activated to have two TCI states. In this case, all control resource sets may be all control resource sets within a carrier or all control resource sets of all carriers configured in a terminal according to a UE capability reporting unit (per carrier or UE).

The two terminal capabilities of the terminal (capacity of the terminal regarding whether or not the reception operation for single TRP-based PDSCH transmission or SFN PDSCH transmission can be dynamically changed and whether or not the reception operation for single TRP-based PDCCH transmission or SFN PDCCH transmission can be dynamically changed For UE capabilities), the UE may include and transmit two pieces of information in one single UE capability report. Also, the two terminal capabilities may be defined as independent terminal capabilities. In addition, through reporting the UE capability for PDSCH (device capability for dynamic change of reception operation for single TRP-based PDSCH transmission or SFN PDSCH transmission), UE capability information for PDCCH (single TRP-based PDCCH single transmission or SFN Whether or not the reception operation for PDCCH transmission can be dynamically changed) can also be reported.

25 illustrates an example of an enhanced PDCCH TCI state activation/deactivation MAC-CE (enhanced PDCCH TCI state activation/deactivation MAC-CE) structure in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 25 is a diagram illustrating an Enhanced PDCCH TCI activation/deactivation MAC-CE structure according to an embodiment of the present disclosure.

25 is a form in which a third octet 2510 is added to the structure of FIG. 9, 1st TCI state ID 2525 indicated by the corresponding MAC-CE for the indicated serving cell ID and control resource set index, and 2nd TCI state It can be seen that the 2nd TCI state ID is additionally indicated to activate the ID 2530. If the Serving Cell ID indicated by the corresponding Enhanced PDCCH TCI state activation/deactivation MAC-CE is included in simultaneousTCI-UpdateList1-r16 or simultaneousTCI-UpdateList2-r16, which is higher layer signaling, simultaneousTCI-UpdateList1-r16 or simultaneousTCI-UpdateList2-r16 For other included serving cell IDs, the 1st TCI state ID and 2nd TCI state ID indicated by the corresponding MAC-CE can be simultaneously applied to the control resource set index indicated by the corresponding MAC-CE. For example, the serving cell IDs included in simultaneousTCI-UpdateList1-r16 are 1 to 4, and the serving cell ID, control resource set index, 1st TCI state ID, and 2nd TCI state ID indicated through the corresponding MAC-CE are 2, If 1, 0, 1, TCI state IDs 0 and 1 are simultaneously activated for control resource set 1 existing in serving cells 1, 3, and 4 through the corresponding MAC-CE.

<Fifth Embodiment: Basic Beam Operation of PDCCH and PDSCH from After Receiving TCI State Configuration Information to Before MAC-CE Activation>

As an embodiment of the present disclosure, when the UE receives higher layer configuration information about TCI states for PDCCH and PDSCH and receives PDCCH and PDSCH until receiving MAC-CE indicating activation of the corresponding TCI state It describes which default beam to receive.

Until the UE receives higher layer signaling tci-StatesPDCCH-ToAddList, which is the TCI state setting for the PDCCH, and receives the MAC-CE for activating the TCI state for the control resource set, the UE receives the initial access for PDCCH reception (initial It can be assumed that the SSB checked in access) has a QCL relationship (ie, it can be assumed that the DMRS of the PDCCH and the SSB checked during initial access have a QCL relationship). Similarly, until the UE receives upper layer signaling tci-StatesToAddModList, which is the TCI state setting for the PDSCH, and MAC-CE for activating the TCI state for the PDSCH, the UE's DMRS of the PDSCH and the SSB checked during initial access are mutually exclusive. It can be assumed that QCL-TypeA and QCL-TypeD have a QCL relationship.

<Sixth Embodiment: Basic beam operation of SFN PDCCH and SFN PDSCH from after receiving TCI state configuration information to before activating MAC-CE>

As an embodiment of the present disclosure, for the multi-TRP based SFN PDCCH and PDSCH transmission mentioned in the above embodiment 4-1, configuration based on higher layer signaling, indication based on L1 signaling, or configuration of higher layer signaling and L1 signaling When the UE is notified by a combination of the based indication schemes, the PDCCH until the UE receives higher layer configuration information about the TCI state for the PDCCH and PDSCH and receives the MAC-CE indicating activation of the corresponding TCI state In case of receiving PDSCH and PDSCH, description will be made on which default beam to receive.

As described above, the terminal may define terminal capabilities capable of informing the base station that reception of a single TRP-based PDSCH transmission and multiple TRP-based SFN PDSCH transmissions can be dynamically switched. Through the corresponding UE capability report, the UE can dynamically switch reception of a single TRP-based PDSCH transmission and multiple TRP-based SFN PDSCH transmissions. That is, for a corresponding terminal, the base station may dynamically perform scheduling for single TRP-based PDSCH transmission and multiple TRP-based SFN PDSCH transmission through DCI. For example, the number of TCI states indicated by the TCI state field in the DCI may be adjusted and indicated. Conversely, if the UE does not report the corresponding UE capability and receives higher layer signaling for multi-TRP based SFN PDSCH and SFN PDCCH transmission, the UE can only receive SFN PDCCH and SFN PDSCH transmission. Therefore, since the UE can receive only SFN PDCCH and SFN PDSCH transmissions in a specific situation or time point, additional definition of basic beam operation of PDCCH and PDSCH may be required depending on when the corresponding time point is defined. The corresponding point in time can be determined based on two criteria as follows. The criterion for the corresponding time point may be determined in advance with a common understanding between the UE and the base station, or the base station may set a specific time point to the UE through higher layer signaling.

[Standard 6-1] After MAC-CE reception for TCI state indication for PDCCH and PDSCH

If the UE does not report the corresponding UE capability and receives higher layer signaling for multi-TRP based SFN PDSCH and SFN PDCCH transmission, the UE may be able to receive only the SFN PDCCH and SFN PDSCH transmission, and at that time, the PDCCH And it may be after MAC-CE reception for TCI state indication for PDSCH. That is, the UE may be able to receive the PDCCH and the PDSCH even based on a single TRP rather than the SFN method before receiving the MAC-CE for indicating the TCI state for the PDCCH and the PDSCH. Therefore, from receiving the TCI state configuration information for the PDCCH and PDSCH to before receiving the MAC-CE for indicating the TCI state for the PDCCH and PDSCH, the UE uses the SSB and QCL relationships confirmed by the DMRS of the PDCCH and the PDSCH during initial access. Assuming you have it, you can use it for receiving.

[Criterion 6-2] After receiving TCI state configuration information or SFN PDCCH and PDSCH configuration information

If the UE does not report the corresponding UE capability and receives higher layer signaling for multi-TRP based SFN PDSCH and SFN PDCCH transmission, the UE may be able to receive only the SFN PDCCH and SFN PDSCH transmission, and at that time, the PDCCH And it may be after receiving TCI state configuration information for PDSCH or configuration information on SFN PDCCH and SFN PDSCH. Therefore, since reception of both the PDCCH and the PDSCH may have to be performed by the SFN method after receiving the corresponding information, one of the following various methods can be used for determining the basic beam for SFN reception of the PDCCH and the PDSCH. can

[Method 6-2-1]

The UE may store received power information (eg, L1-RSRP information) for each of the plurality of SSBs received during initial access. In addition, the SSB checked and used during initial access may have the largest value among corresponding received power information items. After the UE receives the TCI state configuration information for the PDCCH and PDSCH and before receiving the MAC-CE for the TCI state of the PDCCH and PDSCH, in addition to the SSB checked and used in the initial access, the second highest received power It can be assumed that PDCCH and PDSCH reception have a QCL relationship for an SSB having information. Therefore, when receiving the PDCCH and PDSCH, both the SSB used for initial access and the SSB having the second highest received power information can be reference RSs of QCL-TypeA and QCL-TypeD.

[Method 6-2-2]

After the UE receives the TCI state configuration information for the PDCCH and the PDSCH until receiving the MAC-CE for the TCI state of the PDCCH and the PDSCH, the UE transmits the first and second TCI states among the TCI state configuration information of the PDSCH to the PDCCH and It can be considered as a basic beam when receiving PDSCH. Therefore, when receiving the PDCCH and the PDSCH, both the first and second TCI states among the TCI state configuration information of the PDSCH may become reference RSs of QCL-TypeA and QCL-TypeD.

[Method 6-2-3]

After the UE receives the TCI state configuration information for the PDCCH and the PDSCH and before receiving the MAC-CE for the PDCCH and the TCI state of the PDSCH, the UE receives the first and second TCIs among the TCI state configuration information of the PDCCH for PDCCH reception. state is used, and for PDSCH reception, the first and second TCI states among TCI state configuration information of PDSCH may be considered as a basic beam. Therefore, when receiving the PDCCH, both the first and second TCI states among the TCI state configuration information of the PDCCH can be reference RSs of QCL-TypeA and QCL-TypeD, and when receiving the PDSCH, the first and second TCI states among the TCI state configuration information of the PDSCH Both TCI states can be reference RSs of QCL-TypeA and QCL-TypeD. At this time, in the case of control resource set 0, the same TCI states as those of PDSCH may be used.

[Method 6-2-4]

From the time the UE receives the TCI state configuration information for the PDCCH and the PDSCH until the MAC-CE for the TCI state of the PDCCH and the PDSCH is received, in addition to the SSB that was checked and used during the initial access, among the TCI state configuration information of the PDSCH The first TCI state may be considered as a basic beam when receiving PDCCH and PDSCH. Therefore, both the SSB and the first TCI state among the TCI state configuration information of the PDSCH, which were checked and used during initial access when receiving the PDCCH and PDSCH, can become reference RSs of QCL-TypeA and QCL-TypeD.

[Method 6-2-5]

If the UE receives the base station-based SFN scheme through higher layer signaling for transmission of multiple TRP-based SFN PDSCH and SFN PDCCH, some of the TCI state configuration information of the PDSCH includes all channel parameters (eg, Doppler Shift, Doppler Spread, Average Delay, Delay Spread) are set, but certain parameters (eg, Average Delay, Delay Spread) can be set to be ignored. The method of ignoring the corresponding specific parameters may be notified to the terminal through configuration through higher layer signaling, indication through L1 signaling, and a combination of configuration through higher layer signaling and indication through L1 signaling. For example, among TCI state configuration information of PDSCH, TCI state#1 has QCL-TypeA as the type of qcl-info1, has NZP CSI-RS#1 as its reference RS, and dropParameterType in qcl-info1 of the corresponding TCI state. (For example, Type1: Average Delay, Delay Spread, Type2: Delay Spread, Type3: Doppler Shift, Doppler Spread, ??) is set to Type3, the terminal uses NZP, which is the reference RS of qcl-info1 of TCI state#1 It can be seen that the channel parameter information obtained through CSI-RS#1 is Average Delay, Delay Spread, and through this, from the reference RS of TCI state setting information of other indexes and different TRPs to which QCL-TypeA can be indicated. It can implicitly recognize that it is transmitted.

After the UE receives the TCI state configuration information for the PDCCH and the PDSCH until receiving the MAC-CE for the PDCCH and the TCI state of the PDSCH, the UE can indicate the complete QCL-TypeA among the TCI state configuration information of the PDSCH. The first TCI state among the TCI states to which the method in which the th TCI state and channel parameters that can be delivered through the TCI state are partially ignored (eg, the setting of the dropParameterType, etc.) is applied is used as the primary beam when receiving the PDCCH and PDSCH. can be considered Therefore, when receiving the PDCCH and PDSCH, the first TCI state that can indicate the complete QCL-TypeA among the TCI state configuration information of the PDSCH can be the reference RS of QCL-TypeA and QCL-TypeD, and can be transmitted through the TCI state. The reference RS of the first TCI state among the TCI states to which a method in which some channel parameters are ignored (eg, the dropParameterType setting, etc.) is applied is the reference RS for the remaining channel parameters excluding the channel parameters ignored according to the setting, , can be the reference RS of QCL-TypeD.

26A illustrates an example of a terminal operation for primary beams of a PDCCH and a PDSCH in a wireless communication system according to various embodiments of the present disclosure.

26B illustrates an example of an operation of a base station for primary beams of a PDCCH and a PDSCH in a wireless communication system according to various embodiments of the present disclosure.

Specifically, FIGS. 26A and 26B are diagrams illustrating operations of a base station and a terminal for primary beams of a PDCCH and a PDSCH according to an embodiment of the present disclosure. The terminal transmits information related to repeated PDCCH transmission (eg, at least one or part of PDCCH repetition transmission method, whether soft combining is possible, soft combining possible level, necessary constraints for soft combining, etc.) to the base station with terminal capability. May report (2600, 2650). In addition, the UE may additionally report the UE capabilities for multi-TRP based SFN PDCCH and PDSCH transmission (eg, at least one or part of the UE capabilities mentioned in the 4-1 embodiment) to the base station (2601, 2651 ). The base station may receive this and transmit configuration information for the PDCCH (eg, configuration information for the control resource set and search space) to the terminal (2602, 2652), and the base station additionally transmits configuration information for repeated PDCCH transmission (eg, configuration information for the control resource set and search space). For example, the repeated transmission method, the number of repeated transmissions, the repeated transmission interval, the repeated transmission period, the PDCCH monitoring period in which repeated transmission is assumed, the control resource set and search space in which repeated transmission is set, etc.) may be transmitted to the terminal (2603, 2653 ). In addition, the base station may additionally transmit explicit connection configuration-related information (eg, aggregation level, PDCCH candidate group, frequency resource, etc.) to the terminal during repeated PDCCH transmissions (2604, 2654). In addition, the base station may indicate and configure the multi-TRP based SFN PDCCH/PDSCH transmission scheme with L1 signaling, higher layer signaling, or a combination of L1 signaling and higher layer signaling (2605, 2655). This may be based on at least one of the various methods described in the fourth embodiment described above. If the UE is configured with higher layer signaling for the SFN PDCCH and the SFN PDSCH, the UE reports UE capability capable of informing the base station that reception of a single TRP-based PDSCH transmission and multiple TRP-based SFN PDSCH transmissions can be dynamically switched. If not, two things can be considered as described above for the start time at which only reception of the SFN PDCCH and the SFN PDSCH are possible (2606, 2656). If the start point at which only reception of the SFN PDCCH and SFN PDSCH is possible follows [Criterion 6-1], that is, after receiving the MAC-CE for indicating the TCI state for the PDCCH and the PDSCH, the SFN PDCCH and the SFN PDSCH When only reception is possible, the terminal may perform a first PDCCH / PDSCH basic beam determination operation (2608, 2658), and the base station determines the PDCCH and PDSCH according to the corresponding first PDCCH / PDSCH basic beam to match understanding with the terminal. PDSCH may be transmitted. As the first PDCCH/PDSCH basic beam determination operation, from receiving TCI state configuration information for the PDCCH and PDSCH to before receiving MAC-CE for indicating the TCI state for the PDCCH and PDSCH, the UE uses the DMRS of the PDCCH and PDSCH Assuming that it has a QCL relationship with the SSB checked during initial access, it can be used for reception. If the start point at which only reception of SFN PDCCH and SFN PDSCH is possible follows [Criterion 6-2], that is, reception of SFN PDCCH and SFN PDSCH is only possible after receiving TCI state configuration information or SFN PDCCH and PDSCH configuration information. If possible, the terminal may perform a second PDCCH / PDSCH basic beam determination operation (2607, 2657), and the base station transmits the PDCCH and PDSCH according to the corresponding second PDCCH / PDSCH basic beam to match understanding with the terminal can As the second PDCCH/PDSCH basic beam determination operation, from after receiving the TCI state configuration information for the PDCCH and PDSCH to before receiving the MAC-CE for indicating the TCI state for the PDCCH and PDSCH, the UE performs the above-described [Method 6- 2-1] to [Method 6-2-5].

27A illustrates an example of a structure of a terminal in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 27A is a diagram illustrating a structure of a terminal in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 27A , a terminal may include a transceiver, which refers to a terminal receiving unit 2711 and a terminal transmitting unit 2712, a memory (not shown), and a terminal processing unit 2713 (or a terminal control unit or processor). According to the communication method of the terminal described above, the transmission/reception units 2711 and 2712, the memory and the terminal processing unit 2713 of the terminal may operate. However, the components of the terminal are not limited to the above-described examples. For example, a terminal may include more or fewer components than the aforementioned components. In addition, the transceiver, memory, and processor may be implemented in a single chip form.

The transmitting/receiving unit may transmit/receive signals with the base station. Here, the signal may include control information and data. To this end, the transceiver unit may include an RF transmitter for up-converting and amplifying the frequency of a transmitted signal, and an RF receiver for low-noise amplifying a received signal and down-converting the frequency. However, this is only one embodiment of the transceiver, and components of the transceiver are not limited to the RF transmitter and the RF receiver.

Also, the transceiver may receive a signal through a wireless channel, output the signal to the processor, and transmit the signal output from the processor through the wireless channel.

The memory may store programs and data required for operation of the terminal. In addition, the memory may store control information or data included in signals transmitted and received by the terminal. The memory may include a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media. Also, there may be a plurality of memories.

In addition, the processor may control a series of processes so that the terminal can operate according to the above-described embodiment. For example, the processor may control components of the terminal to simultaneously receive a plurality of PDSCHs by receiving DCI composed of two layers. There may be a plurality of processors, and the processors may perform component control operations of the terminal by executing a program stored in a memory.

27B illustrates an example of a structure of a base station in a wireless communication system according to various embodiments of the present disclosure. Specifically, FIG. 27B is a diagram illustrating a structure of a base station in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 27B , a base station may include a base station receiving unit 2721 and a transmitting/receiving unit that refers to a base station transmitting unit 2722, a memory (not shown), and a base station processing unit 2723 (or a base station control unit or processor). According to the communication method of the base station described above, the transmission/reception units 2721 and 2722, the memory and the base station processing unit 2723 of the base station may operate. However, components of the base station are not limited to the above-described examples. For example, a base station may include more or fewer components than those described above. In addition, the transceiver, memory, and processor may be implemented in a single chip form.

The transmission/reception unit may transmit/receive signals with the terminal. Here, the signal may include control information and data. To this end, the transceiver unit may include an RF transmitter for up-converting and amplifying the frequency of a transmitted signal, and an RF receiver for low-noise amplifying a received signal and down-converting the frequency. However, this is only one embodiment of the transceiver, and components of the transceiver are not limited to the RF transmitter and the RF receiver.

Also, the transceiver may receive a signal through a wireless channel, output the signal to the processor, and transmit the signal output from the processor through the wireless channel.

The memory may store programs and data necessary for the operation of the base station. In addition, the memory may store control information or data included in signals transmitted and received by the base station. The memory may include a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media. Also, there may be a plurality of memories.

The processor may control a series of processes so that the base station operates according to the above-described embodiment of the present disclosure. For example, the processor may configure and transmit two layers of DCIs including allocation information for a plurality of PDSCHs and may control each element of the base station. There may be a plurality of processors, and the processors may perform a component control operation of the base station by executing a program stored in a memory.

Methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented in software, a computer readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium are configured for execution by one or more processors in an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

Such programs (software modules, software) may include random access memory, non-volatile memory including flash memory, read only memory (ROM), and electrically erasable programmable ROM. (electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile discs (DVDs), or other It can be stored on optical storage devices, magnetic cassettes. Alternatively, it may be stored in a memory composed of a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

In addition, the program is provided through a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a communication network consisting of a combination thereof. It can be stored on an attachable storage device that can be accessed. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. In addition, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in singular or plural numbers according to the specific embodiments presented. However, the singular or plural expressions are selected appropriately for the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components, and even components expressed in plural are composed of the singular number or singular. Even the expressed components may be composed of a plurality.

Meanwhile, in the detailed description of the present disclosure, specific embodiments have been described, but various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments and should not be defined by the scope of the claims described below as well as those equivalent to the scope of these claims.

Claims (2)

In a method of operating a terminal in a wireless communication system,
Receiving a first control signal from a base station;
generating a second control signal based on the first control signal; and
Transmitting the second control signal to the base station,
method.
In a terminal in a wireless communication system,
transceiver; and
includes at least one processor;
The at least one processor,
Receiving a first control signal from a base station;
generating a second control signal based on the first control signal;
configured to transmit the second control signal to the base station;
Terminal.

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