WO2024232677A1 - Method and apparatus for energy saving in wireless communication system - Google Patents

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A method performed by a user equipment (UE) in a wireless communication system may comprise the steps of: camping on a second cell activated for transmission of data among at least one cell associated with a first cell of a base station for random access; receiving, from the base station, the data on the second cell; and receiving, from the base station, information indicating deactivation of the second cell on the second cell.

Description

Method and device for energy saving in wireless communication system

The present disclosure relates to a wireless communication system, and more particularly, to a method and device for energy saving of a base station in a wireless communication system.

5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band, such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (㎜Wave), such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low delay time that is reduced by one-tenth.

In the early stages of 5G mobile communication technology, the goal was to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). The technologies included beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2 Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

Currently, discussions are underway on improving and enhancing the initial 5G mobile communication technology in consideration of the services that the 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

In addition, standardization of wireless interface architecture/protocols for technologies such as the Industrial Internet of Things (IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) to provide nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step RACH for NR to simplify random access procedures is also in progress, and standardization of system architecture/services for 5G baseline architecture (e.g. Service based Architecture, Service based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal is also in progress.

When such 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, which will require enhanced functions and performance of 5G mobile communication systems and integrated operation of connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, AI service support, metaverse service support, drone communications, etc. using extended reality (XR), artificial intelligence (AI), and machine learning (ML) to efficiently support augmented reality (AR), virtual reality (VR), and mixed reality (MR).

In addition, the development of these 5G mobile communication systems will require new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, and AI (Artificial Intelligence) from the design stage and AI-based communication technology that implements end-to-end AI support functions to realize system optimization, and ultra-high-performance communication and computing resources to provide services with a level of complexity that goes beyond the limits of terminal computing capabilities. It could serve as a basis for the development of next-generation distributed computing technologies that utilize this.

According to one embodiment of the present disclosure, a device and method for effectively providing a service in a mobile communication system are provided.

The present disclosure provides a method and device for energy saving of a base station in a wireless communication system.

A method performed by a user equipment (UE) in a wireless communication system may include the steps of camping on a second cell activated for transmission of data among at least one cell associated with a first cell of a base station for random access, receiving the data from the base station on the second cell, and receiving from the base station on the second cell information indicating deactivation of the second cell.

According to one embodiment of the present disclosure, a device and method capable of effectively providing a service in a wireless communication system can be provided.

The effects obtainable from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by a person skilled in the art to which the present disclosure belongs from the description below.

According to one embodiment of the present disclosure, by defining a signal transmission method of a base station in a wireless communication system, the problem of excessive energy consumption can be solved and high energy efficiency can be achieved.

FIG. 1 is a diagram illustrating an example of a basic structure of a time-frequency resource domain of a 5G system according to one embodiment.

FIG. 2 is a diagram showing an example of a time domain mapping structure and a beam sweeping operation of a synchronization signal according to one embodiment.

FIG. 3 is a diagram illustrating an example of a random access procedure according to one embodiment.

FIG. 4 is a diagram illustrating an example of a procedure in which a terminal reports terminal capability (UE (user equipment) capability) information to a base station according to one embodiment.

FIG. 5 is a diagram illustrating an example of a control resource set (CORESET) as a time-frequency resource to which a PDCCH is mapped according to one embodiment.

FIG. 6 is a diagram showing an example of how DCI and DMRS are mapped to REG, which is a basic unit of a downlink control channel according to one embodiment.

FIG. 7 is a diagram illustrating an example of base station beam allocation according to TCI state settings according to one embodiment.

FIG. 8 is a diagram illustrating an example of a hierarchical signaling method for dynamic allocation of PDCCH beams of NR according to one embodiment.

FIG. 9 is a diagram illustrating a TCI indication MAC CE signaling structure for the PDCCH DMRS according to one embodiment.

FIG. 10 is a diagram for explaining a method in which a base station and a terminal transmit and receive data by considering downlink data channels and rate matching resources according to one embodiment.

FIG. 11 is a diagram illustrating an example of an aperiodic CSI reporting method when the CSI-RS offset is 0 according to one embodiment.

FIG. 12 is a diagram illustrating an example of an aperiodic CSI reporting method when a CSI-RS offset is 1 according to one embodiment.

FIG. 13 is a diagram illustrating an example of settings for a bandwidth part in a 5G communication system according to one embodiment.

FIG. 14 is a diagram illustrating an example of DRX (Discontinuous Reception) in a 5G communication system according to one embodiment.

FIG. 15 is a diagram illustrating a method for a base station to deactivate the base station to a terminal to save base station energy according to one embodiment.

FIG. 16 is a diagram illustrating signaling between a base station and a terminal for a method in which a base station instructs a terminal to deactivate the base station to save base station energy according to one embodiment.

FIG. 17 is a diagram illustrating a method for a base station to deactivate a terminal using a base station deactivation timer to save base station energy according to one embodiment.

FIG. 18 is a diagram illustrating the operation of a base station when the base station receives a scheduling request for uplink traffic of a terminal during a base station inactivity period according to one embodiment.

FIG. 19 is a diagram illustrating an operation for a terminal to receive scheduling from a currently connected data cell when uplink traffic of the terminal occurs during a data cell inactivity period and SR is transmitted to an access cell according to an embodiment of the present invention.

FIG. 20 is a diagram illustrating an operation in which a terminal receives scheduling from another activated data cell within an access cell when uplink traffic of the terminal is generated during a data cell inactivity period and SR is transmitted to an access cell according to an embodiment of the present invention.

FIG. 21 is a diagram illustrating an operation in which a terminal receives scheduling from a previously connected data cell when uplink traffic of the terminal occurs during a data cell inactivity period and SR is transmitted to the data cell according to an embodiment of the present invention.

FIG. 22 is a diagram illustrating an operation in which a terminal receives scheduling from another data cell within an access cell when uplink traffic of the terminal occurs during a data cell inactivity period and SR is transmitted to the data cell according to an embodiment of the present invention.

FIG. 23 is a diagram illustrating an operation in which a terminal receives scheduling from another data cell within an access cell when uplink traffic of a terminal occurs during a data cell inactivity period according to an embodiment of the present invention and a wakeup signal (WUS) corresponding to SR is transmitted to data cells.

FIG. 24 is a diagram of a base station inactivity time structure in an environment where a base station allows SR reception during the base station inactivity time according to one embodiment and notifies other terminals within the base station that the base station is not inactive when an SR is received.

Figure 25 is a drawing explaining a terminal transceiver device according to one embodiment.

FIG. 26 is a block diagram illustrating an exemplary configuration of a terminal according to one embodiment.

FIG. 27 is a block diagram illustrating an exemplary configuration of a base station according to one embodiment of the present disclosure.

For convenience of explanation, devices not directly related to the present disclosure may be omitted from illustration and description.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. In addition, when describing the present disclosure, if it is determined that a specific description of a related known function or configuration may unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of the functions in the present disclosure, and these may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification.

The advantages and features of the present disclosure, and the methods for achieving them, will become apparent by referring to the embodiments described in detail below together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms, and the embodiments are provided only to make the disclosure of the present disclosure complete and to fully inform a person having ordinary skill in the art to which the present disclosure belongs of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be loaded onto a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce an article of manufacture that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing apparatus, a series of operational steps may be performed on the computer or other programmable data processing apparatus to produce a computer-executable process, so that the instructions executing the computer or other programmable data processing apparatus may also provide steps for executing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a particular logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be performed substantially concurrently, or the blocks may sometimes be performed in reverse order, depending on the functionality they perform.

Here, the term '~ part' used in the present embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be in an addressable storage medium and may be configured to reproduce one or more processors. Accordingly, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. In addition, the components and '~parts' may be implemented to play one or more CPUs within the device or secure multimedia card. Also, in an embodiment, the '~part' may include one or more processors.

In the following description of the present disclosure, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present disclosure, the detailed description thereof will be omitted. Hereinafter, an embodiment of the present disclosure will be described with reference to the attached drawings.

In the following description, terms used to identify connection nodes, terms referring to network objects, terms referring to messages, terms referring to interfaces between network objects, terms referring to various identification information, etc. are examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

In the following description, the terms physical channel and signal may be used interchangeably with data or control signals. For example, PDSCH (physical downlink shared channel) is a term referring to a physical channel through which data is transmitted, but PDSCH may also be used to refer to data. That is, in the present disclosure, the expression 'transmitting a physical channel' may be interpreted equivalently to the expression 'transmitting data or a signal through a physical channel'.

In the present disclosure below, upper signaling means a signal transmission method in which a base station transmits a signal to a terminal using a downlink data channel of a physical layer, or a terminal transmits a signal to a base station using an uplink data channel of a physical layer. Upper signaling can be understood as RRC (radio resource control) signaling or MAC (media access control) control element (CE).

For convenience of explanation below, this disclosure uses terms and names defined in the 3GPP NR (New Radio: 5th generation mobile communication standard) standard. However, this disclosure is not limited by the above terms and names, and can be equally applied to systems conforming to other standards. In addition, the term terminal can refer to not only mobile phones, smart phones, IoT devices, and sensors, but also other wireless communication devices.

Hereinafter, the base station is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, a gNB, an eNode B, an eNB, a Node B, a BS (Base Station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (User Equipment), an MS (Mobile Station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. Of course, it is not limited to the above examples.

In order to handle the explosive increase in mobile data traffic, the initial standard of the 5G (5th Generation) system or New Radio access technology (NR), the next-generation communication system after LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)) and LTE-A (LTE-Advanced or E-UTRA Evolution) has been completed. While the existing mobile communication systems have focused on conventional voice/data communications, the 5G system aims to satisfy various services and requirements, such as the eMBB (enhanced Mobile BroadBand) service for improving the existing voice/data communications, the Ultra-Reliable and Low Latency Communication (URLLC) service, and the massive MTC (Machine Type Communication) service that supports a large number of machine-to-machine communications.

While the transmission bandwidth of a single carrier of the existing LTE and LTE-A systems is limited to a maximum of 20 MHz, the 5G system aims to provide ultra-high-speed data services of up to several Gbps by utilizing an ultra-wide bandwidth that is much wider than this. Accordingly, the 5G system is considering ultra-high frequency bands from several GHz to up to 100 GHz, where it is relatively easy to secure ultra-wide bandwidth frequencies, as candidate frequencies. Additionally, it is possible to secure wide bandwidth frequencies for the 5G system through frequency reallocation or allocation among frequency bands ranging from several hundred MHz to several GHz used in existing mobile communication systems.

The radio waves in the above ultra-high frequency band are also called millimeter waves (mmWave) because their wavelengths are on the order of a few millimeters. However, in the ultra-high frequency band, the path loss of radio waves increases in proportion to the frequency band, so the coverage of mobile communication systems decreases.

In order to overcome the disadvantage of coverage reduction in the above ultra-high frequency band, beamforming technology can be applied to concentrate the radiated energy of radio waves to a predetermined target point using a plurality of antennas to increase the transmission distance of radio waves. That is, a signal to which the beamforming technology is applied has a relatively narrow beam width of the signal, and the radiated energy is concentrated within the narrowed beam width, thereby increasing the transmission distance. The beamforming technology can be applied to each of the transmitter and receiver. In addition to the effect of increasing coverage, the beamforming technology has the effect of reducing interference in an area other than the beamforming direction. In order for the beamforming technology to operate properly, an accurate measurement and feedback method of the transmission/reception beams are required. The beamforming technology can be applied to a control channel or a data channel corresponding one-to-one between a predetermined terminal and a base station. In addition, beamforming technology can be applied to common signals transmitted by a base station to multiple terminals within a system, such as a synchronization signal, a physical broadcast channel (PBCH), a control channel for transmitting system information, and a data channel, to increase coverage. When beamforming technology is applied to the common signal, beam sweeping technology, which transmits a signal by changing the beam direction, is additionally applied so that the common signal can reach terminals located at any location within a cell.

Another requirement of the 5G system is an ultra-low latency service with a transmission delay of approximately 1 ms between the transmitter and receiver. One way to reduce the transmission delay is to design a frame structure based on a short TTI (Transmission Time Interval) compared to LTE and LTE-A. TTI is a basic time unit for performing scheduling, and the TTI of the existing LTE and LTE-A systems is 1 ms corresponding to the length of one subframe. For example, in order to satisfy the requirement for the ultra-low latency service of the 5G system, a short TTI of 0.5 ms, 0.25 ms, and/or 0.125 ms, which is shorter than that of the existing LTE and LTE-A systems, is possible.

In addition, the present disclosure provides a method and device for reducing energy consumption of a base station in a mobile communication system. According to the present disclosure, the problem of excessive energy consumption of a base station in a mobile communication system can be solved and high energy efficiency can be achieved.

FIG. 1 is a diagram illustrating an example of a basic structure of a time-frequency resource domain of a 5G system according to one embodiment. That is, FIG. 1 is a diagram illustrating a basic structure of a time-frequency resource domain, which is a radio resource domain in which data or control channels of a 5G system are transmitted.

Referring to Figure 1, the horizontal axis in Figure 1 may refer to the time domain and the vertical axis may refer to the frequency domain. The minimum transmission unit in the time domain of the 5G system is an OFDM (Orthogonal Frequency Division Multiplexing) symbol.

(102) symbols can be combined to form one slot (106),

A plurality of slots can be grouped to form one subframe (105). The length of the subframe is 1.0 ms, and 10 subframes can be grouped to form a 10 ms frame (114). The minimum transmission unit in the frequency domain can be a subcarrier, and the bandwidth of the entire system transmission bandwidth can be composed of a total of N _BW (104) subcarriers.

According to one embodiment, the basic unit of resources in the time-frequency domain is a Resource Element (RE) (112), which may be represented by an OFDM symbol index and a subcarrier index. A Resource Block (RB or Physical Resource Block, PRB) is a resource block in the frequency domain.

It can be defined as (110) consecutive subcarriers. In 5G systems.

=12, and the data rate can increase in proportion to the number of RBs scheduled to the terminal.

According to one embodiment, in a 5G system, a base station may map data in RB units, and scheduling may be performed for RBs that generally constitute one slot for a given terminal. That is, in a 5G system, a basic time unit in which scheduling is performed may be a slot, and a basic frequency unit in which scheduling is performed may be an RB.

In one embodiment, the number of OFDM symbols

can be determined by the length of the cyclic prefix (CP) added to each symbol to prevent interference between symbols. For example, if a normal CP is applied,

=14, and if Extended CP is applied,

=12 can be. Extended CP can be applied to a system with a relatively long transmission distance than general CP, so that orthogonality between symbols can be maintained. In the case of general CP, since the ratio of CP length to symbol length is maintained at a constant value, the overhead due to CP can be maintained constant regardless of the subcarrier spacing. That is, if the subcarrier spacing is small, the symbol length becomes long, and thus the CP length can also become long. Conversely, if the subcarrier spacing is large, the symbol length becomes short, and thus the CP length can be reduced. The symbol length and CP length can be inversely proportional to the subcarrier spacing.

According to one embodiment, in a 5G system, various frame structures can be supported by adjusting the subcarrier spacing to satisfy various services and requirements.

- For example, from the perspective of the operating frequency band, the larger the subcarrier spacing, the more advantageous it is for recovering phase noise in the high-frequency band.

- For example, from the perspective of transmission time, if the subcarrier spacing is large, the symbol length in the time domain becomes shorter, and consequently the slot length becomes shorter, which is advantageous for supporting ultra-low delay services such as URLLC.

- For example, in terms of cell size, the longer the CP length, the larger the cell can be supported, so the smaller the subcarrier spacing, the larger the cell can be supported. In mobile communications, a cell is a concept that refers to the area covered by one base station.

Subcarrier spacing, CP length, etc. may be essential information for OFDM transmission and reception, and the base station and terminal must recognize the subcarrier spacing, CP length, etc. as common values to perform smooth transmission and/or reception.

[Table 1] shows the relationship between the subcarrier spacing configuration (μ), subcarrier spacing (Δf), and CP length supported in the 5G system.

[Table 2] shows the number of symbols per slot for each subcarrier spacing setting (μ) for the general CP.

), number of slots per frame (

), number of slots per subframe (

) is indicated.

[Table 3] shows the number of symbols per slot for each subcarrier spacing setting (μ) in the case of extended CP.

), number of slots per frame (

), number of slots per subframe (

) is indicated.

According to one embodiment, in the initial stage of introducing a 5G system, at least coexistence or dual mode operation with existing LTE or/and LTE-A (hereinafter referred to as LTE/LTE-A) systems is expected. Accordingly, the existing LTE/LTE-A can provide stable system operation to terminals, and the 5G system can play a role of providing improved services to the terminals. Accordingly, the frame structure of the 5G system needs to include at least the frame structure or essential parameter set of LTE/LTE-A (subcarrier spacing = 15 kHz).

For example, when comparing a frame structure (hereinafter referred to as frame structure A) with a subcarrier spacing setting of μ=0 and a frame structure (hereinafter referred to as frame structure B) with a subcarrier spacing setting of μ=1, compared to frame structure A, frame structure B can have a subcarrier spacing and RB size twice as large, and a slot length and a symbol length twice as small. In the case of frame structure B, two slots can be configured into one subframe, and 20 subframes can be configured into one frame.

By generalizing the frame structure of the above-described 5G system, high scalability can be provided by making the essential parameter sets, such as subcarrier spacing, CP length, and/or slot length, have an integer multiple relationship with each other for each frame structure. In addition, a subframe of a fixed length of 1 ms can be defined to represent a reference time unit independent of the frame structure.

The above-described frame structures can be applied to correspond to various scenarios. From the perspective of cell size, since a longer CP length can support a larger cell, frame structure A can support a relatively larger cell than frame structure B. For example, from the perspective of operating frequency band, a larger subcarrier spacing is advantageous for phase noise recovery in a high-frequency band, so frame structure B can support a relatively higher operating frequency than frame structure A. For example, from the perspective of service, since a shorter slot length, which is a basic time unit of scheduling, is advantageous for supporting an ultra-low-delay service such as URLLC, frame structure B can be relatively more suitable for a URLLC service than frame structure A.

In the following description of the present disclosure, uplink (UL) may be referred to as a wireless link through which a terminal transmits data or a control signal to a base station, and downlink (DL) may be referred to as a wireless link through which a base station transmits data or a control signal to a terminal.

According to one embodiment, in the initial access phase where a terminal first accesses a system, the terminal can synchronize a downlink time and frequency from a synchronization signal transmitted by a base station through a cell search, and can obtain a cell identifier (cell ID). Then, the terminal can receive a physical broadcast channel (PBCH) using the obtained cell ID, and can obtain a master information block (MIB), which is essential system information, from the PBCH. In addition, the terminal can receive system information (System Information Block, SIB) transmitted by the base station to obtain control information associated with cell-common transmission and/or reception. For example, the control information associated with cell-common transmission and/or reception may include random access-related control information, paging-related control information, and/or common control information for various physical channels.

According to one embodiment, a synchronization signal is a signal that serves as a reference for cell search, and a subcarrier spacing may be applied for each frequency band to suit a channel environment such as phase noise. In the case of a data channel or a control channel, a subcarrier spacing may be applied differently depending on the service type in order to support various services as described above.

FIG. 2 is a diagram showing an example of a time domain mapping structure of a synchronization signal and a beam sweeping operation.

For the purpose of explanation, the following components can be defined:

- PSS (Primary Synchronization Signal): PSS is a signal that serves as the basis for DL time/frequency synchronization and can provide some cell ID information.

- SSS (Secondary Synchronization Signal): SSS serves as a reference for DL time/frequency synchronization and provides some remaining information such as cell ID. In addition, SSS can serve as a reference signal for demodulation of PBCH.

- PBCH (Physical Broadcast Channel): PBCH can provide MIB (Master Information Block), which is essential system information required for transmission and reception of data channels and control channels of the terminal. For example, essential system information can include information such as search space-related control information indicating radio resource mapping information of the control channel, scheduling control information for a separate data channel transmitting system information, and/or SFN (System Frame Number), which is a frame-unit index that serves as a timing reference.

- SS/PBCH Block (Synchronization Signal/PBCH Block or SSB): An SS/PBCH block consists of N OFDM symbols and can be a combination of PSS, SSS, and/or PBCH. In a system to which beam sweeping technology is applied, an SS/PBCH block is the minimum unit to which beam sweeping is applied. In a 5G system, N can be 4. A base station can transmit up to L SS/PBCH blocks, and the L SS/PBCH blocks are mapped within a half frame (0.5 ms). And the L SS/PBCH blocks are periodically repeated in units of a predetermined period P. The period P can be notified to a terminal by signaling from the base station. If there is no separate signaling for the period P, the terminal applies a pre-agreed default value.

Figure 2 shows an example in which beam sweeping is applied to SS/PBCH block units over time.

Referring to FIG. 2, according to an embodiment, UE1 (205) can receive an SS/PBCH block using a beam radiated in the direction of #d0 (203) by beamforming applied to SS/PBCH block #0 at time t1 (201). And UE2 (206) can receive an SS/PBCH block using a beam radiated in the direction of #d4 (204) by beamforming applied to SS/PBCH block #4 at time t2 (202). A terminal (or, UE) can obtain an optimal synchronization signal through a beam radiated from a base station in the direction where the terminal is located. For example, it may be difficult for UE1 (205) to obtain time/frequency synchronization and essential system information from an SS/PBCH block through a beam radiated in the direction of #d4, which is far from the location of UE1.

According to one embodiment, in addition to the initial access procedure, the terminal (or UE) may also receive the SS/PBCH block to determine whether the radio link quality of the current cell is maintained at a certain level or higher. In addition, in a handover procedure in which the terminal moves connection from the current cell to an adjacent cell, the terminal may determine the radio link quality of the adjacent cell and receive the SS/PBCH block of the adjacent cell to obtain time/frequency synchronization of the adjacent cell.

According to one embodiment, after a terminal acquires MIB and system information from a base station through an initial access procedure, the terminal may perform a random access procedure to switch a link with the base station to a connected state (e.g., connected state or RRC_CONNECTED state). When the terminal completes the random access procedure, the terminal may be switched to a connected state, and one-to-one communication may be performed between the base station and the terminal. The random access procedure will be described in detail below with reference to FIG. 3.

Figure 3 is a diagram showing an example of a random access procedure.

Referring to FIG. 3, as a first step (310) of a random access procedure according to an embodiment, a terminal (or UE) may transmit a random access preamble to a base station. For example, a random access preamble, which is a message transmitted first by a terminal in a random access procedure, may be referred to as message 1.

According to one embodiment, a base station (e.g., a gNB or an eNB) can measure a transmission delay value between a terminal and the base station from a random access preamble and synchronize uplink. The terminal can arbitrarily select which random access preamble to use within a random access preamble set given by system information in advance. For example, the terminal can select a designated random access preamble within the random access preamble set and transmit it to the base station.

According to one embodiment, the initial transmission power of the random access preamble may be determined according to the pathloss between the base station and the terminal measured by the terminal. In addition, the terminal may determine the transmission beam direction of the random access preamble from the synchronization signal received from the base station and transmit the random access preamble.

According to one embodiment, in the second step (320), the base station may transmit an uplink transmission timing adjustment command to the terminal based on a transmission delay value measured from the random access preamble received in the first step (310). In addition, the base station may transmit an uplink resource and power control command to be used by the terminal as scheduling information. The scheduling information may include control information for an uplink transmission beam of the terminal.

If the terminal does not receive the Random Access Response (RAR) (or message 2), which is the scheduling information for message 3 in the second step (320), from the base station within a specified time, the first step (310) can be performed again. For example, if the terminal does not receive the RAR from the base station within a specified time, the terminal may recognize that the base station did not receive the preamble, and may perform the first step (310) again.

When the terminal performs the first step (310) again, the terminal can increase the probability of the base station receiving the random access preamble by transmitting it while increasing the transmission power of the random access preamble by a predetermined step (power ramping).

According to one embodiment, in the third step (330), the terminal may transmit uplink data (message 3) including its terminal ID to the base station through an uplink data channel (Physical Uplink Shared Channel, PUSCH) using the uplink resources allocated in the second step (320). For example, the transmission timing of the uplink data channel for transmitting Message 3 may follow the timing control command received from the base station in the second step (320). For example, the transmission power of the uplink data channel for transmitting Message 3 may be determined based on the power control command received from the base station in the second step (320) and the power ramping value of the random access preamble. The uplink data channel for transmitting Message 3 may mean the first uplink data signal that the terminal transmits to the base station after the terminal transmits the random access preamble.

According to one embodiment, in step 4 (340), if the base station determines that the terminal has performed random access without collision with other terminals, the base station may transmit data (message 4) including the ID of the terminal that transmitted uplink data in step 3 (330) to the terminal. If the terminal receives the signal transmitted by the base station in step 4 (340) from the base station, the terminal may determine that the random access is successful. The terminal may transmit HARQ-ACK information indicating whether message 4 was successfully received to the base station through an uplink control channel (Physical Uplink Control Channel, PUCCH).

According to one embodiment, if the data transmitted by the terminal in step 3 (330) collides with data from another terminal and the base station fails to receive a data signal from the terminal, the base station may not transmit any more data to the terminal. Accordingly, if the terminal fails to receive data transmitted from the base station in step 4 (340) within a certain period of time, it may determine that the random access procedure has failed and may start over from step 1 (310).

According to one embodiment, when a random access procedure is successfully completed, the terminal is switched to a connected state, and one-to-one communication becomes possible between the base station and the terminal. The base station can receive UE capability information from the terminal in the connected state and adjust scheduling by referring to the UE capability information of the terminal. Through the UE capability information, the terminal can inform the base station whether the terminal itself supports a certain function and/or the maximum allowable value of the function supported by the terminal. Accordingly, the UE capability information reported by each terminal to the base station can have different values for each terminal.

For example, a terminal may report UE capability information including at least some of the following control information to a base station as UE capability information.

- Control information related to frequency bands supported by the terminal

- Control information related to channel bandwidth supported by the terminal

- Control information related to the maximum modulation method supported by the terminal

- Control information related to the maximum number of beams supported by the terminal

- Control information related to the maximum number of layers supported by the terminal

- Control information related to CSI reporting supported by the terminal

- Control information on whether the terminal supports frequency hopping

- Bandwidth-related control information when supporting carrier aggregation (CA)

- Control information on whether cross carrier scheduling is supported when supporting carrier aggregation

FIG. 4 is a diagram illustrating an example of a procedure in which a terminal reports terminal capability information to a base station according to one embodiment.

Referring to FIG. 4, in step 410 according to one embodiment, a base station (402) may transmit a UE capability information request message to a terminal (401). In response to the base station's request for UE capability information, the terminal may transmit UE capability information to the base station in step 420.

Through the above-described process, a terminal connected to a base station can be in the RRC_CONNECTED state, and a terminal connected to a base station can perform one-to-one communication. Conversely, a terminal that is not connected can be in the RRC_IDLE state, and the operations of a terminal in that state can be divided as follows.

- Operates terminal-specific DRX (Discontinuous Reception) cycle set by upper layer

- Action to receive paging messages from the core network

- Obtain system information

- Measurement actions related to surrounding cells and cell reselection

In one embodiment, in order to reduce the energy and time consumed for initial access of a terminal in a 5G system, a new terminal state called RRC_INACTIVE is defined. An RRC_INACTIVE terminal performs the following operations in addition to the operations performed by an RRC_IDLE terminal.

- Storage of AS (Access stratum) information required for cell connection

- Terminal-specific DRX (discontinuous reception) cycle operation set by the RRC layer

- Setting up and periodically updating RNA (RAN-based notification area) that can be utilized during handover by RRC layer

- Monitoring of RAN (radio access network)-based paging messages transmitted via I-RNTI (radio network temporary identifier)

Below, a scheduling method for a base station to transmit downlink data to a terminal or instruct a terminal to transmit uplink data is described.

According to one embodiment, downlink control information (DCI) may be control information that a base station transmits to a terminal via downlink, and the DCI may include downlink data scheduling information or uplink data scheduling information for a given terminal. For example, the base station may independently channel-code the DCI for each terminal and then transmit it to each terminal via a downlink physical control channel, PDCCH (Physical Downlink Control Channel).

According to one embodiment, a base station may operate by applying a predetermined DCI format according to the purpose, such as whether it is scheduling information for downlink data (downlink assignment) for a terminal to be scheduled, whether it is scheduling information for uplink data (uplink grant), and/or whether it is DCI for power control.

According to one embodiment, the base station may transmit downlink data to the terminal through a Physical Downlink Shared Channel (PDSCH), which is a physical channel for downlink data transmission, or on the PDSCH. For example, scheduling information, such as a specific mapping position in the time and frequency domain of the PDSCH, a modulation scheme, HARQ-related control information, and/or power control information, may be notified by the base station to the terminal through DCI related to downlink data scheduling information among DCIs transmitted through the PDCCH.

According to one embodiment, a terminal may transmit uplink data to a base station through a PUSCH (Physical Uplink Shared Channel), which is a physical channel for uplink data transmission. For example, scheduling information, such as a specific mapping position in the time and frequency domains of the PUSCH, a modulation scheme, HARQ-related control information, and/or power control information, may be notified by the base station to the terminal through DCI related to uplink data scheduling information among DCIs transmitted through the PDCCH.

FIG. 5 is a diagram illustrating an example of a control resource set (CORESET) as a time-frequency resource to which a PDCCH is mapped according to one embodiment.

Referring to FIG. 5, according to an embodiment, two control resource sets (e.g., control resource set #1 (501) and control resource set #2 (502)) may be set within a UE bandwidth part (510) in the frequency axis and one slot (520) in the time axis. For example, the control resource sets (501, 502) may be set to a specific frequency resource (503) within the entire UE bandwidth part (510) in the frequency axis. The time axis may be set to one or more OFDM symbols, and this may be defined as a control resource set duration (Control Resource Set Duration, 504).

According to one embodiment, control resource set #1 (501) may be set to a control resource set length of 2 symbols, and control resource set #2 (502) may be set to a control resource set length of 1 symbol.

According to one embodiment, the base station may set one or more CORESETs to the terminal through upper layer signaling (e.g., System Information, Master Information Block (MIB), Radio Resource Control (RRC) signaling). Setting a CORESET to the terminal may be referred to as providing information such as a CORESET identifier (Identity), a frequency position of the CORESET, and/or a symbol length of the CORESET. The information that the base station provides to the terminal to set the CORESET may include at least some of the information included in [Table 4].

In one embodiment, CORESET is in the frequency domain.

It can be composed of RBs and in the time domain.

symbols. For example, NR PDCCH may be composed of one or more CCEs (Control Channel Elements). One CCE may be composed of six REGs (Resource Element Groups), and a REG may be defined as 1 RB during 1 OFDM symbol. Within a CORESET, REGs may be indexed in time-first order, starting with REG index 0 from the first OFDM symbol of the CORESET, the lowest RB.

According to one embodiment, interleaved and non-interleaved methods may be supported as transmission methods for PDCCH. The base station may configure whether interleaved or non-interleaved transmission is performed for each CORESET to the terminal through upper layer signaling. For example, interleaving may be performed in units of REG bundles. For example, a REG bundle may be defined as a set of one or more REGs. The terminal may determine a CCE-to-REG mapping method in the corresponding CORESET based on whether interleaved or non-interleaved transmission is configured from the base station in the following manner as shown in [Table 5].

According to one embodiment, the base station may signal to the terminal information such as which symbol within a slot the PDCCH is mapped to and/or the transmission period.

Figure 6 is a diagram explaining an example of how DCI and DMRS are mapped to REG, which is the basic unit of a downlink control channel.

Referring to FIG. 6, REG (603), which is a basic unit of a downlink control channel according to one embodiment, may include both REs to which DCI is mapped and regions to which a demodulation reference signal (DMRS) (605), which is a reference signal for decoding DCI, is mapped. In addition, three DMRSs (605) may be transmitted within one REG (603).

Hereinafter, the search space of the PDCCH is described. The number of CCEs required to transmit the PDCCH can be 1, 2, 4, 8, or 16 depending on the aggregation level (AL). Different numbers of CCEs can be used for link adaptation of the downlink control channel. For example, when AL=L, one downlink control channel can be transmitted through L CCEs. The terminal performs blind decoding to detect a signal without knowing information about the downlink control channel, and a search space representing a set of CCEs can be defined to perform blind decoding.

In one embodiment, a search space is a set of downlink control channel candidates, which are CCEs that a terminal should attempt to decode, at a given aggregation level. Since there are multiple aggregation levels that form a single bundle with 1, 2, 4, 8, and 16 CCEs, the terminal can have multiple search spaces. A search space set can be defined as a set of search spaces at all configured aggregation levels.

According to one embodiment, the search space may be classified into a common search space (CSS) and a UE-specific search space (USS). A certain group of UEs or all UEs may search the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling or paging messages for system information (System Information Block (SIB)). For example, the UE may receive scheduling allocation information of the PDSCH for receiving system information by searching the common search space of the PDCCH.

For example, 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-arranged CCEs. The scheduling allocation information for terminal-specific PDSCH or PUSCH can be received by the terminal by examining the terminal-specific search space of the PDCCH. The terminal-specific search space can be defined terminal-specifically as a function of the terminal's ID (Identity) and various system parameters.

According to one embodiment, the base station may set configuration information for a search space of a PDCCH to the terminal via higher layer signaling (e.g., SIB, MIB, and/or RRC signaling). For example, the base station may set, to the terminal, the number of PDCCH candidates in each aggregation level L, a monitoring period for the search space, a monitoring occasion per symbol within a slot for the search space, a search space type (common search space or terminal-specific search space), a combination of a DCI format and an RNTI to be monitored in the search space, and/or a CORESET index to be monitored in the search space.

For example, parameters for the search space for PDCCH may include information such as [Table 6] below.

According to one embodiment, the base station may configure one or more search space sets for the terminal according to (or based on) the configuration information. According to one embodiment, the base station may configure search space set 1 and search space set 2 for the terminal. In search space set 1, the terminal may be configured to monitor DCI format A scrambled with X-RNTI in a common search space, and in search space set 2, the terminal may be configured to monitor DCI format B scrambled with Y-RNTI in a terminal-specific search space.

According to the configuration information according to one embodiment, one or more 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 a common search space, and search space set #3 and search space set #4 may be set as terminal-specific search spaces.

According to one embodiment, in a common search space, a terminal may monitor the following combinations of DCI formats and RNTIs, although not limited to the following examples.

- DCI format 0_0/1_0 with CRC (cyclic redundancy check) scrambled by C-RNTI, CS-RNTI, SP (semi-persistent)-CSI (channel state information)-RNTI, RA-RNTI, TC-RNTI (Temporary Cell 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

- DCI format 2_4 with CRC scrambled by CI-RNTI

- DCI format 2_5 with CRC scrambled by AI-RNTI

- DCI format 2_6 with CRC scrambled by PS-RNTI

- DCI format 2_7 with CRC scrambled by PEI-RNTI

According to one embodiment, in a terminal-specific search space, a terminal may monitor the following combinations of DCI formats and RNTIs, although 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 above RNTIs may follow the following definitions and uses:

C-RNTI (Cell RNTI): For terminal-specific PDSCH or PUSCH scheduling purposes.

TC-RNTI (Temporary Cell RNTI): For terminal-specific PDSCH scheduling purposes.

CS-RNTI (Configured Scheduling RNTI): For terminal-specific PDSCH scheduling purposes that are set semi-statically.

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

P-RNTI (Paging RNTI): Used for scheduling PDSCH where paging is transmitted.

SI-RNTI (System Information RNTI): Used for scheduling PDSCH where system information is transmitted.

INT-RNTI (Interruption RNTI): Used to indicate whether pucturing is in progress 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): Used to indicate power control commands for PUCCH.

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

The DCI formats described above can follow the definitions shown in [Table 7] below.

CORESET p, the search space of aggregation level L in the search space set s can be expressed as shown in the following mathematical expression 1.

The description of the parameters in [Mathematical Formula 1] is as follows.

The value can be 0 for a common search space.

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

Below, we will specifically describe a method for setting the TCI (transmission configuration indicator) state for PDCCH (or PDCCH DMRS) in a 5G communication system.

According to one embodiment, the base station may be able to set and indicate a TCI state for a PDCCH (or a PDCCH DMRS) through appropriate signaling. According to the description, the base station may be able to set and indicate a TCI state for a PDCCH (or a PDCCH DMRS) through appropriate signaling.

In one embodiment, the TCI state is to announce or indicate a QCL (Quasi co-location) relationship between the PDCCH (or PDCCH DMRS) and other RSs or channels. When the first reference antenna port A (reference RS #A) and the second antenna port B (target RS #B) are QCLed with each other, it means that the terminal is allowed to apply some or all of the large-scale channel parameters estimated at antenna port A (or, the first reference antenna port A) to the channel measurement from antenna port B (or, the second antenna port B).

For example, QCL may need to relate different parameters depending on the situation, such as 1) time tracking affected by average delay and delay spread, 2) frequency tracking affected by Doppler shift and Doppler spread, 3) radio resource management (RRM) affected by average gain, and/or 4) beam management (BM) affected by spatial parameters. Accordingly, NR supports four types of QCL relationships, as shown in Table 8 below.

According to one embodiment, the spatial RX parameter may collectively refer to some or all of 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.

According to one embodiment, the QCL relationship can be set to the terminal via the RRC parameters TCI-State and/or QCL-Info as shown in Table 9 below. For example, referring to Table 9, the base station can set one or more TCI states to the terminal and inform the terminal of up to two QCL relationships (qcl-Type1, qcl-Type2) for the RS (e.g., target RS) referencing the ID of the TCI state. Each QCL information (QCL-Info) included in each TCI state can include the serving cell index of the reference RS indicated by each QCL information, the BWP index, the type and ID of the reference RS, and/or the QCL type described in Table 8.

FIG. 7 is a diagram for explaining a base station beam allocation operation according to a TCI state setting according to one embodiment.

Referring to FIG. 7, a base station according to an embodiment can transmit information about N different beams to a terminal through N different TCI states. For example, when N=3, the base station can cause the qcl-Type2 parameter included in three TCI states (700, 705, 710) to be associated with CSI-RS or SSB corresponding to different beams and set to QCL type D, and the base station can notify or indicate that antenna ports referencing different TCI states (700, 705, or 710) have different spatial Rx parameter relationships. That is, the base station can notify or indicate that antenna ports referencing different TCI states (700, 705, 710) are associated with different beams.

Specifically, the TCI state combinations applicable to the PDCCH DMRS antenna port are as shown in [Table 10] below. The 4th row in [Table 10] is the combination that the terminal assumes before RRC configuration, and configuration after RRC is not possible.

NR supports a hierarchical signaling method as illustrated in Fig. 8 for dynamic allocation of PDCCH beams.

FIG. 8 is a diagram illustrating an example of a hierarchical signaling method for dynamic allocation of PDCCH beams of NR.

Referring to FIG. 8, a base station according to an embodiment can set N TCI states (805, 810, ..., 820) to a terminal through RRC signaling (800), and can set some of them as TCI states for CORESET (825). Thereafter, the base station can indicate one of the TCI states (830, 835, 840) for CORESET to the terminal through MAC CE signaling (845). Thereafter, the terminal can receive a PDCCH based on beam information included in the TCI state indicated by the MAC CE signaling.

FIG. 9 is a diagram illustrating a TCI indication MAC CE signaling structure for the PDCCH DMRS.

Referring to FIG. 9, TCI indication MAC CE signaling for PDCCH DMRS according to one embodiment may be composed of 2 bytes (16 bits), and the TCI indication MAC CE signaling for PDCCH DMRS may include 1 bit of reserved bit (910), 5 bits of serving cell ID (915), 2 bits of BWP ID (920), 2 bits of CORESET ID (925), and/or 6 bits of TCI state ID (930).

In one embodiment, the base station may indicate one of the TCI state lists included in the CORESET configuration via MAC CE signaling. Until another TCI state is indicated to the CORESET via another MAC CE signaling, the terminal may consider or identify that the same QCL information is applied to one or more search spaces connected to the CORESET.

The above-described PDCCH beam allocation method has a problem that it is difficult to instruct a beam change faster than the MAC CE signaling delay, and also has a disadvantage that the same beam is applied to each CORESET regardless of the search space characteristics, making flexible PDCCH beam operation difficult. The following embodiments of the present disclosure provide a more flexible PDCCH beam setting and operation method. In describing the following embodiments of the present disclosure, several distinct examples are provided for the convenience of explanation, but these are not mutually exclusive and can be applied in appropriate combination depending on the situation.

According to one embodiment, the base station can set one or more TCI states for a specific control resource set to the terminal, and can activate one of the at least one set TCI states via a MAC CE activation command.

For example, {TCI state#0, TCI state#1, TCI state#2} may be set as the TCI state for control resource set#1, and the base station may transmit to the terminal a command to activate to assume TCI state#0 as the TCI state for control resource set#1 through MAC CE. Based on the activation command for the TCI state received through MAC CE, the terminal can correctly receive the DMRS of the corresponding control resource set based on the QCL information in the activated TCI state.

In one embodiment, with respect to a control resource set (control resource set #0) whose index is set to 0, if (in case that) the terminal has not received a MAC CE activation command for a TCI state of the control resource set #0, the terminal may assume or identify that the DMRS transmitted in the control resource set #0 is QCL with an SS/PBCH block identified in a non-contention-based random access process that is not triggered by an initial access process or a PDCCH command.

In one embodiment, with respect to a control resource set (control resource set #X) whose index is set to a value other than 0, if (in case that) the terminal has not been set a TCI state for the control resource set #X, or has been set one or more TCI states but has not received a MAC CE activation command that activates one of them, the terminal may assume or identify that the DMRS transmitted in the control resource set #X is QCL with the SS/PBCH block identified during the initial access process.

Below, downlink control information (DCI) in a 5G system is specifically described.

According to one embodiment, in a 5G system, scheduling information for uplink data (or, Physical Uplink Shared Channel (PUSCH)) or downlink data (or, Physical Downlink Shared Channel (PDSCH)) may be transmitted from a base station to a terminal via DCI. The terminal may monitor a DCI format for fallback and a DCI format for non-fallback with respect to the PUSCH or PDSCH. The fallback DCI format may be composed of fixed fields selected between the base station and the terminal, and the non-fallback DCI format may include configurable fields.

According to one embodiment, the DCI may be transmitted through or on a Physical Downlink Control Channel (PDCCH) after going through a channel coding and modulation process.

According to one embodiment, a Cyclic Redundancy Check (CRC) is attached to a DCI message payload, and the CRC can be scrambled with a Radio Network Temporary Identifier (RNTI) corresponding to the identity of a UE. Different RNTIs can be used depending on the purpose for which the DCI message is transmitted (e.g., UE-specific data transmission, power control command, or random access response). That is, the RNTI can be transmitted by being included in the CRC calculation process without being explicitly transmitted. When receiving a DCI message transmitted on a PDCCH, the UE can verify the CRC using the allocated RNTI, and if the CRC verification result is correct, the UE can identify that the DCI message has been transmitted to the UE.

For example, a 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 P-RNTI. A DCI notifying a Slot Format Indicator (SFI) may be scrambled with SFI-RNTI. A DCI notifying a Transmit Power Control (TPC) may be scrambled with TPC-RNTI. A DCI scheduling a UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

According to one embodiment, DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, and the CRC can be scrambled with C-RNTI. For example, DCI format 0_0 with CRC scrambled with C-RNTI can include at least some of the information of [Table 11].

DCI format 0_1 can be used as a fallback DCI for scheduling PUSCH, and the CRC can be scrambled with C-RNTI. For example, DCI format 0_1 with CRC scrambled with C-RNTI can include at least some of the information in [Table 12].

According to one embodiment, PEKFMAUS, DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, and the CRC can be scrambled with C-RNTI. For example, DCI format 1_0 with CRC scrambled with C-RNTI can include at least some of the information of [Table 13].

DCI format 1_1 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI can include the following information, for example, as shown in Table 14.

Below, we describe a time domain resource allocation method for data channels in a 5G communication system.

According to one embodiment, the base station may set up a table for time domain resource allocation information for a downlink data channel (Physical Downlink Shared Channel, PDSCH) and/or an uplink data channel (Physical Uplink Shared Channel, PUSCH) to the terminal through higher layer signaling (e.g., RRC signaling).

According to one embodiment, the base station may set a table consisting of at most maxNrofDL-Allocations=16 entries for PDSCH, and may set a table consisting of at most maxNrofUL-Allocations=16 entries for PUSCH. For example, the time domain resource allocation information may include PDCCH-to-PDSCH slot timing or PDCCH-to-PUSCH slot timing, information about a position and a length of a start symbol in which a PDSCH or a PUSCH is scheduled within a slot, and/or a mapping type of the PDSCH or PUSCH. For example, the PDCCH-to-PDSCH slot timing may correspond to a time interval in slot units between a time point at which a PDCCH is received and a time point at which a PDSCH scheduled by the received PDCCH is transmitted, and may be denoted as K0. For example, the PDCCH-to-PUSCH slot timing may correspond to the time interval in slot units between the time a PDCCH is received and the time when a PUSCH scheduled by the received PDCCH is transmitted, and may be denoted as K2.

For example, at least some of the information included in [Table 15] and [Table 16] below can be notified, set, or instructed from the base station to the terminal.

According to one embodiment, the base station can notify, configure or instruct the terminal to one of the entries of the table for the time domain resource allocation information via L1 (layer 1) signaling (e.g., DCI). For example, the base station can instruct the terminal to at least one of the entries of the table for the time domain resource allocation information based on a 'time domain resource allocation' field in the DCI. The terminal can obtain time domain resource allocation information for PDSCH or PUSCH based on the DCI received from the base station.

Below, we describe a method for allocating frequency domain resources for data channels in a 5G communication system.

According to one embodiment, a 5G system may support two types of methods for indicating frequency domain resource allocation information for a downlink data channel (Physical Downlink Shared Channel, PDSCH) and an uplink data channel (Physical Uplink Shared Channel, PUSCH), Resource Allocation Type 0 and Resource Allocation Type 1.

In one embodiment, the 5G system may support resource allocation type 0.

For example, RB allocation information can be notified from the base station to the terminal in the form of a bitmap for an RBG (Resource Block Group). An RBG can be composed of a set of consecutive VRBs (Virtual RBs), and the size P of the RBG can be determined based on a value set as a higher layer parameter (rbg-Size) and/or a size value of a bandwidth part defined in [Table 17] below.

- Size

The total number of RBGs in bandwidth part i (

) can be defined as follows.

-

Each bit of the bitmap of bit size can correspond to each RBG. The RBGs can be indexed in order of increasing frequency starting from the lowest frequency position of the bandwidth part. Within the bandwidth part

For the RBGs of the dog, from RBG#0 to RBG#(

-1) This RBG bitmap can be mapped from MSB to LSB.

The terminal can determine that an RBG corresponding to the bit value (e.g., 1) is allocated when a specific bit value in the bitmap is 1, and can determine that an RBG corresponding to the bit value (e.g., 0) is not allocated when a specific bit value in the bitmap is 0.

In one embodiment, the 5G system may support resource allocation type 1.

- For example, RB allocation information can be notified from the base station to the terminal as information on the start position and length of consecutively allocated VRBs. Interleaving or non-interleaving can be additionally applied to consecutively allocated VRBs. The resource allocation field of resource allocation type 1 can be composed of a resource indication value (RIV), and the RIV indicates the start point (

) and the length of the consecutively allocated RBs (

) can be composed of. More specifically,

RIV within the bandwidth part of the size can be defined as follows.

According to one embodiment, a base station may semi-statically set time and frequency transmission resources and various transmission/reception parameters for a physical downlink shared channel (PDSCH) or an uplink data channel (PUSCH) to support non-grant-based transmission/reception for a downlink data channel (Physical Uplink Shared Channel) or a physical downlink shared channel (PUSCH) to a terminal.

For example, a base station may set at least some of the information included in [Table 18] through upper layer signaling (e.g., RRC signaling) for the purpose of supporting downlink (DL) SPS (Semi-Persistent Scheduling) to a terminal.

According to one embodiment, DL SPS may be set in a primary cell or a secondary cell, and DL SPS may be set in one cell within one cell group.

5G systems can support two types of non-grant (also called Configured Grant, Grant free, etc.)-based transmission methods for uplink data channels (Physical Uplink Shared Channel, PUSCH): Type-1 PUSCH transmission with a configured grant and Type-2 PUSCH transmission with a configured grant.

In one embodiment, the 5G system may support non-grant-based PUSCH transmission type-1.

According to one embodiment, in the non-grant-based PUSCH transmission type-1, the base station may configure specific time/frequency resources (600) allowing non-grant-based PUSCH transmission to the terminal through higher layer signaling (e.g., RRC signaling). For example, the base station may configure time axis allocation information (601), frequency axis allocation information (602), and/or period information (603) for the resource (600) to the terminal as illustrated in FIG. 6. In addition, the base station may configure various parameters for PUSCH transmission to the terminal through higher layer signaling (e.g., frequency hopping, DMRS configuration, MCS (modulation and coding scheme) table, MCS, RBG (Resource Block Group) size, number of repetition transmissions, and/or RV (Redundancy Version)). The configuration information that the base station configures to the terminal may include at least some of the configuration information included in [Table 19].

According to one embodiment, when a terminal receives configuration information for non-grant-based PUSCH transmission type-1 from a base station, the terminal may transmit a PUSCH periodically with the configured resources (600) without the base station's approval. For example, various parameters required for transmitting a PUSCH (e.g., frequency hopping, DMRS configuration, MCS, RBG (Resource Block Group) size, number of repeated transmissions, RV (Redundancy Version), number of precoding and layers, antenna ports, and/or frequency hopping offset, etc.) may all follow the configuration values notified by the base station.

In one embodiment, the 5G system may support non-grant-based PUSCH transmission type-2.

For example, in the non-grant-based PUSCH transmission type-2, the base station may set some of the information (e.g., period information (603), etc.) about specific time/frequency resources (600) that allow non-grant-based PUSCH transmission to the terminal through higher layer signaling (e.g., RRC signaling). In addition, the base station may set various parameters for PUSCH transmission to the terminal through higher layer signaling (e.g., frequency hopping, DMRS configuration, MCS table, RBG (Resource Block Group) size, number of repetition transmissions, and/or RV (Redundancy Version), etc.). For example, the base station may set at least some of the configuration information included in Table 20 to the terminal through higher layer signaling.

According to one embodiment, a base station may transmit a DCI composed of specific DCI field values for the purpose of scheduling activation or scheduling release for DL SPS and UL grant Type 2 to a terminal.

For example, a base station may set a Configured Scheduling-RNTI (CS-RNTI) to a terminal, and the terminal may monitor a DCI format whose CRC is scrambled with the CS-RNTI. If the CRC of the DCI format received by the terminal is scrambled with the CS-RNTI, a New Data Indicator (NDI) is set to '0', and the DCI field satisfies the following [Table 21] (in case that), the terminal may regard or identify the DCI as a command to activate transmission and/or reception for DL SPS or UL grant Type 2.

According to one embodiment, the base station may set a Configured Scheduling-RNTI (CS-RNTI) to the terminal, and the terminal may monitor a DCI format whose CRC is scrambled with the CS-RNTI. If the CRC of the DCI format received by the terminal is scrambled with the CS-RNTI, a New Data Indicator (NDI) is set to '0', and the DCI field satisfies the following [Table 22], the terminal may regard or identify the DCI as a command to release transmission and/or reception for DL SPS or UL grant Type 2.

According to one embodiment, since a DCI indicating a release for a DL SPS or UL grant Type 2 follows or is based on a DCI format corresponding to DCI format 0_0 or DCI format 1_0, and since DCI format 0_0 or 1_0 does not include a Carrier Indicator Field (CIF), a UE may always need to monitor a PDCCH in a cell in which DL SPS or UL grant Type 2 is configured in order to receive a release command for DL SPS or UL grant Type 2 for the specific cell. Even if the specific cell is configured for cross-carrier scheduling, the UE may always monitor DCI format 1_0 or DCI format 0_0 in the cell in order to receive a release command for DL SPS or UL grant Type 2 configured for the cell.

Below, we will specifically describe carrier aggregation and scheduling methods in 5G communication systems.

According to one embodiment, a terminal may be configured with a plurality of cells (Cells or CCs (Component Carriers)) from a base station, and may be configured with whether to perform cross-carrier scheduling for the plurality of cells configured in the terminal. If (in case that) cross-carrier scheduling is configured for a specific cell (e.g., Cell A, Scheduled Cell), PDCCH monitoring for Cell A may not be performed in Cell A, and PDCCH monitoring for another cell indicated by cross-carrier scheduling (e.g., Cell B, Scheduling Cell) may be performed. The scheduled cell (Cell A) and the scheduling cell (Cell B) may be configured with different numerologies. For example, the numerologies may include subcarrier spacing, and/or Cyclic Prefix. When the numerologies of cells A and B are different, when the PDCCH of cell B schedules the PDSCH of cell A, the following minimum scheduling offset may be additionally considered between the PDCCH and the PDSCH.

Cross-carrier scheduling method

◆ Subcarrier spacing of cell B (

) is the subcarrier spacing of cell A (

) is less than, the PDSCH can be scheduled from the next PDSCH slot corresponding to X symbols after the last symbol of the PDCCH received from cell B. For example, X is

It may vary depending on

When =15kHz, X=4 symbols,

When =30kHz, X=4 symbols,

When =60kHz, it can be defined as X=8 symbols.

◆ Subcarrier spacing of cell B (

) is the subcarrier spacing of cell A (

) is greater than, the PDSCH can be scheduled from the point in time corresponding to X symbols after the last symbol of the PDCCH received from cell B. For example, X is

It may vary depending on

When =30kHz, X=4 symbols,

When =60kHz, X=8 symbols,

When =120kHz, it can be defined as X=12 symbols.

Below, the rate matching operation and puncturing operation are described in detail.

When a time and frequency resource A, through which an arbitrary symbol sequence A is to be transmitted, overlaps with an arbitrary time and frequency resource B, a rate matching or puncturing operation may be considered for transmission and reception operations of channel A that considers resource C in the area where resources A and B overlap. The specific operations are described below.

Rate Matching Operation

- According to one embodiment, the base station can map and transmit channel A only for the remaining resource regions excluding resource C corresponding to the overlapping region with resource B among the entire resources A to transmit symbol sequence A to the terminal. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, and resource A is {resource #1, resource #2, resource #3, resource #4} and resource B is {resource #3, resource #5}, the base station can sequentially map and transmit symbol sequence A to {resource #1, resource #2, resource #4}, which are the remaining resources excluding {resource #3} corresponding to resource C among resources A. As a result, the base station can map symbol sequences {symbol #1, symbol #2, symbol #3} to {resource #1, resource #2, resource #4}, respectively, and transmit them.

According to one embodiment, the terminal can determine resources A and resources B from scheduling information for symbol sequence A from the base station, and can thereby determine resource C, which is an area where resources A and resources B overlap. The terminal can receive symbol sequence A, assuming that symbol sequence A is mapped and transmitted in a remaining area excluding resource C among the entire resources A. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, and resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the terminal can assume that symbol sequence A is sequentially mapped to {resource #1, resource #2, resource #4}, which are the remaining resources excluding {resource #3} corresponding to resource C among resources A, and can receive it. As a result, the terminal can assume that the symbol sequence {symbol #1, symbol #2, symbol #3} is transmitted by being mapped to {resource #1, resource #2, resource #4}, respectively, and perform a series of subsequent receiving operations.

Puncturing action

According to one embodiment, if a base station wants to transmit symbol sequence A to a terminal, and there is a resource C corresponding to an area overlapping with resource B among the entire resources A, the base station may map symbol sequence A to the entire resource A, but may not perform transmission in the resource area corresponding to resource C, and may perform transmission only for the remaining resource areas of resource A excluding resource C. For example, if symbol sequence A is composed of {Symbol #1, Symbol #2, Symbol #3, Symbol #4}, and resource A is {Resource #1, Resource #2, Resource #3, Resource #4}, and resource B is {Resource #3, Resource #5}, the base station can map symbol sequence A {Symbol #1, Symbol #2, Symbol #3, Symbol #4} to resource A {Resource #1, Resource #2, Resource #3, Resource #4}, respectively, and the base station can transmit only symbol sequences {Symbol #1, Symbol #2, Symbol #4} corresponding to resources {Resource #1, Resource #2, Resource #4} other than {Resource #3} corresponding to resource C among resources A, and the base station may not transmit {Symbol #3} mapped to {Resource #3} corresponding to resource C. As a result, the base station can transmit symbol sequences {Symbol #1, Symbol #2, Symbol #4} by mapping them to {Resource #1, Resource #2, Resource #4}, respectively.

According to one embodiment, the terminal can determine resources A and resource B from scheduling information for symbol sequence A from the base station, and thereby determine resource C, which is an area where resources A and resource B overlap. The terminal can receive symbol sequence A, assuming that symbol sequence A is mapped to the entire resource A, but transmitted only in the remaining area of resource area A excluding resource C. For example, if symbol sequence A is composed of {symbol #1, symbol #2, symbol #3, symbol #4}, and resource A is {resource #1, resource #2, resource #3, resource #4}, and resource B is {resource #3, resource #5}, the terminal can assume that symbol sequence A {symbol #1, symbol #2, symbol #3, symbol #4} is mapped to resource A {resource #1, resource #2, resource #3, resource #4}, respectively, but {symbol #3} mapped to {resource #3} corresponding to resource C is not transmitted. The terminal can assume and receive that the symbol sequence {symbol #1, symbol #2, symbol #4} corresponding to the remaining resources {resource #1, resource #2, resource #4}, excluding {resource #3} corresponding to resource C among resources A, has been mapped and transmitted. As a result, the terminal can assume that the symbol sequence {symbol #1, symbol #2, symbol #4} has been mapped and transmitted to {resource #1, resource #2, resource #4}, respectively, and perform the following series of receiving operations.

FIG. 10 is a diagram for explaining a method for a base station and a terminal to transmit and/or receive data by considering a downlink data channel and rate matching resources according to one embodiment.

Referring to FIG. 10, a downlink data channel (PDSCH, 1001) and a rate matching resource (1002) according to an embodiment are illustrated. A base station can set one or more rate matching resources (1002) to a terminal through upper layer signaling (e.g., RRC signaling). For example, the rate matching resource (1002) setting information may include time-domain resource allocation information (1003), frequency-domain resource allocation information (1004), and/or period information (1005). In the following, a bitmap corresponding to the frequency-domain resource allocation information (1004) may be referred to as a “first bitmap”, a bitmap corresponding to the time-domain resource allocation information (1003) may be referred to as a “second bitmap”, and a bitmap corresponding to the period information (1005) may be referred to as a “third bitmap”. If all or part of the time and frequency resources of the scheduled data channel (1001) overlap with the set rate matching resources (1002), the base station can rate-match and transmit the data channel (1001) in the rate matching resource (1002) portion. The terminal can perform reception and decoding of data after assuming that the data channel (1001) is rate-matched in the rate matching resource (1002) portion.

According to one embodiment, the base station may dynamically notify or instruct the terminal via DCI whether to rate-match the data channel in the set rate-matching resource portion through additional configuration (corresponding to the "rate-matching indicator" in the DCI format described above). For example, the base station may select some of the set rate-matching resources and group them into rate-matching resource groups, and the base station may instruct the terminal via DCI using a bitmap method whether to rate-match the data channel for each rate-matching resource group.

For example, if four rate matching resources, RMR#1, RMR#2, RMR#3, and RMR#4, are set, the base station can set RMG#1={RMR#1, RMR#2}, RMG#2={RMR#3, RMR#4} as the rate matching groups, and the base station can use 2 bits in the DCI field to instruct the terminal as a bitmap whether to perform rate matching in RMG#1 and RMG#2, respectively. For example, the base station can instruct the terminal as "1" when rate matching is required, and as "0" when rate matching is not required.

According to one embodiment, the 5G system supports the granularity of "RB symbol level" and "RE level" by setting the aforementioned rate matching resource to the terminal. A more specific setting method is described below.

According to one embodiment, a 5G system may support RB symbol level.

According to one embodiment, a terminal may be configured with up to four RateMatchPatterns for each bandwidth part through upper layer signaling, and one RateMatchPattern may include at least one of the following contents:

- For example, as a reserved resource in the bandwidth part, a resource whose time and frequency resource domains are set as a combination of a bitmap at the RB level and a bitmap at the symbol level along the frequency axis can be included in RateMatchPattern. The reserved resource can span one or two slots. A time domain pattern (periodicityAndPattern) in which the time and frequency domains composed of each RB level and symbol level bitmap pair are repeated can be additionally set.

- For example, a resource area corresponding to a time domain pattern set as a search space setting in which the time and frequency domain resource area is set as a control resource set within the bandwidth part and the frequency domain resource area is repeated can be included in RateMatchPattern.

In one embodiment, the 5G system can support RE level.

The terminal can be configured with at least some of the following information via upper layer signaling.

- For example, it may include configuration information for RE corresponding to LTE CRS (Cell-specific Reference Signal or Common Reference Signal) pattern, (lte-CRS-ToMatchAround) as the number of ports of LTE CRS (nrofCRS-Ports) and LTE-CRS-vshift(s) value (v-shift), location information of center subcarrier (Subcarrier) of LTE carrier from reference frequency point (e.g., reference point A) (carrierFreqDL), bandwidth size information of LTE carrier (carrierBandwidthDL), and/or subframe configuration information (mbsfn-SubframConfigList) corresponding to MBSFN (Multicast-broadcast single-frequency network). Based on the above-described information, the terminal may determine the location of the CRS in the NR slot corresponding to the LTE subframe.

- For example, it may include configuration information for a set of resources corresponding to one or more ZP (Zero Power) CSI-RSs within the bandwidth part.

Below, we specifically describe a method for measuring and reporting channel conditions in a 5G communication system.

According to one embodiment, channel state information (CSI) may include a channel quality information (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), an SS/PBCH block resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI), and/or a L1-RSRP (Reference Signal Received Power). The base station may control time and frequency resources for the aforementioned CSI measurement and reporting of the terminal.

For the aforementioned CSI measurement and reporting, the terminal can receive setting information (CSI-ReportConfig) for N (≥1) CSI reports, setting information (CSI-ResourceConfig) for M (≥1) RS transmission resources, and one or two trigger state lists (CSI-AperiodicTriggerStateList, CSI-SemiPersistentOnPUSCH-TriggerStateList) through upper layer signaling.

For example, the setup information for the aforementioned CSI measurement and reporting may include at least one of the information described in [Table 23] to [Table 29].

With respect to the aforementioned CSI report setting (CSI-ReportConfig), each report setting CSI-ReportConfig is associated with a CSI resource setting associated with the report setting. In addition, each report setting CSI ReportConfig can be associated with one downlink (DL) bandwidth part identified by the upper layer parameter bandwidth part identifier (bwp-id) given to CSI-ResourceConfig.

According to one embodiment, for each report setting CSI-ReportConfig, time domain reporting behaviors may be supported, including 'Aperiodic', 'Semi-Persistent' and 'Periodic'. The time domain reporting behavior for each report setting CSI-ReportConfig may be configured from the base station to the terminal by the reportConfigType parameter configured from the upper layer.

According to one embodiment, the semi-persistent CSI reporting method may support 'semi-PersistentOnPUCCH', and/or 'semi-PersistentOnPUSCH'. For example, in case of the periodic or semi-persistent CSI reporting method, the terminal may be configured with PUCCH or PUSCH resources to transmit CSI from the base station through upper layer signaling. The period and slot offset of the PUCCH or PUSCH resources to transmit CSI may be given as a numerology of an uplink (UL) bandwidth portion where the CSI report is configured to be transmitted.

According to one embodiment, for the aperiodic CSI reporting method, the terminal can be scheduled for PUSCH resources to transmit CSI from the base station through L1 signaling (the aforementioned DCI format 0_1).

According to one embodiment, with respect to the aforementioned CSI resource setting (CSI-ResourceConfig), each CSI resource setting CSI-ReportConfig may include S (≥ 1) CSI resource sets. For example, the CSI resource sets may be set by the upper layer parameter csi-RS-ResourceSetList.

According to one embodiment, the CSI resource set list may consist of a non-zero power (NZP) CSI-RS resource set and a SS/PBCH block set, or a CSI-interference measurement (CSI-IM) resource set.

According to one embodiment, each CSI resource setting may be located in a downlink (DL) bandwidth portion identified by a higher layer parameter bwp-id, and the CSI resource setting may be linked to a CSI reporting setting of the same downlink bandwidth portion.

According to one embodiment, the time domain operation of CSI-RS resources within the CSI resource setting can be set to one of 'aperiodic', 'periodic' or 'semi-persistent' from the upper layer parameter resourceType. For example, with respect to periodic or semi-persistent CSI resource setting, the number of CSI-RS resource sets can be limited to S=1, and the configured period and slot offset can be set to a numerology of a downlink bandwidth portion identified by bwp-id.

According to one embodiment, the terminal may receive one or more CSI resource settings for channel or interference measurement from the base station through upper layer signaling. For example, the one or more CSI resource settings may include at least one of the following CSI resources:

- CSI-IM (Channel State Information-Interference Measurement) resource for interference measurement

- NZP CSI-RS (Non-Zero Power Channel State Information-Reference Signal) resource for interference measurement

- NZP CSI-RS resources for channel measurements

According to one embodiment, for CSI-RS resource sets associated with resource settings where the upper layer parameter resourceType is set to 'aperiodic', 'periodic', or 'semi-persistent', a trigger state for CSI report settings where reportType is set to 'aperiodic' and resource settings for channel or interference measurements for one or more component cells (CC) can be set with the upper layer parameter CSI-AperiodicTriggerStateList.

According to one embodiment, aperiodic CSI reporting of a terminal may utilize PUSCH, and periodic CSI reporting may utilize PUCCH. Semi-persistent CSI reporting may be performed using PUSCH when triggered or activated by DCI. As another example, semi-persistent CSI reporting may be performed using PUCCH after being activated by a MAC control element (MAC CE). As described above, CSI resource setting may also be configured as aperiodic, periodic, or semi-persistent. Combinations between CSI reporting settings and CSI resource settings may be supported based on [Table 30] below.

According to one embodiment, aperiodic CSI reporting may be triggered by a "CSI request" field of the aforementioned DCI format 0_1 corresponding to scheduling DCI for PUSCH. For example, a UE may monitor a PDCCH, obtain a DCI format 0_1, and obtain scheduling information and a CSI request indicator for PUSCH.

The CSI request indicator can be set to the NTS (=0, 1, 2, 3, 4, 5, or 6) bit and can be determined by higher layer signaling (reportTriggerSize). One or more aperiodic CSI reporting trigger states that can be set by higher layer signaling (CSI-AperiodicTriggerStateList) can be triggered by the CSI request indicator.

- For example, if all bits in the CSI request field are 0, it can be referenced as not requesting CSI reporting.

- For example, if (in case that) the number of CSI trigger states (M) in the configured CSI-AperiodicTriggerStateLite is greater than 2NTs-1, then according to the mapping relationship that is defined, the M CSI trigger states can be mapped to 2NTs-1, and one of the trigger states of 2NTs-1 can be indicated by the CSI request field.

- For example, if (in case that) the number of CSI trigger states (M) in the configured CSI-AperiodicTriggerStateLite is less than or equal to 2NTs-1, one of the M CSI trigger states can be indicated by the CSI request field.

[Table 31] shows an example of the relationship between a CSI request indicator and a CSI trigger state that can be indicated by the CSI request indicator.

According to one embodiment, a terminal may perform measurements on CSI resources within a CSI trigger state triggered by a CSI request field, and the terminal may generate CSI (e.g., including at least one of CQI, PMI, CRI, SSBRI, LI, RI, or L1-RSRP).

According to one embodiment, the terminal can transmit the acquired CSI using the PUSCH scheduled by the DCI format 0_1. For example, if 1 bit corresponding to the uplink data indicator (UL-SCH indicator) in the DCI format 0_1 indicates "1", the terminal can multiplex and transmit the uplink data (UL-SCH) and the acquired CSI on the PUSCH resource scheduled by the DCI format 0_1. For example, if 1 bit corresponding to the uplink data indicator (UL-SCH indicator) in the DCI format 0_1 indicates "0", the terminal can map and transmit only the CSI without the uplink data (UL-SCH) on the PUSCH resource scheduled by the DCI format 0_1.

Figure 11 is a diagram illustrating an example of an aperiodic CSI reporting method.

Figure 12 is a diagram illustrating an example of an aperiodic CSI reporting method.

Referring to FIG. 11, a terminal according to an embodiment can monitor a PDCCH (1101) to obtain a DCI format 0_1, and can obtain scheduling information and CSI request information for a PUSCH (1105) from the obtained DCI format 0_1. The terminal can obtain resource information for a CSI-RS (1102) to be measured from a received CSI request indicator.

According to one embodiment, the terminal can determine when to perform measurement on the transmitted CSI-RS (1102) resource based on the time point of receiving the DCI format 0_1 and the parameter (e.g., aperiodicTriggeringOffset) for offset in the CSI resource set configuration (e.g., NZP CSI-RS resource set configuration (NZP-CSI-RS-ResourceSet). That is, the terminal can perform measurement on the CSI-RS (1102) resource based on the DCI format 0_1 and the CSI resource set configuration.

For example, the terminal can receive an offset value X of the parameter aperiodicTriggeringOffset in the NZP-CSI-RS resource set configuration from the base station through upper layer signaling, and the configured offset value X can be referenced as an offset between a slot in which a DCI triggering aperiodic CSI reporting is received and a slot in which a CSI-RS resource is transmitted. For example, the aperiodicTriggeringOffset parameter value and the offset value X can have a mapping relationship as described in [Table 32].

Referring to FIG. 12, the offset value may be set to X=0. In this case, the terminal may receive the CSI-RS (1102) based on a slot (e.g., slot 0 of FIG. 11) in which the DCI format 0_1 that triggers the aperiodic CSI report is received, and the terminal may report the CSI information measured with the received CSI-RS to the base station through the PUSCH (1105). The terminal may obtain scheduling information for the PUSCH (1105) for the CSI report from the DCI format 0_1 (e.g., information corresponding to each field of the DCI format 0_1).

For example, the terminal can obtain information about the slot in which the PUSCH (1105) is to be transmitted from the aforementioned time domain resource allocation information for the PUSCH (1105) in DCI format 0_1. In an example of FIG. 11, the terminal obtains the K2 value corresponding to the slot offset value for the PDCCH-to-PUSCH as 3, and accordingly, the PUSCH (1105) can be transmitted in slot 3 (1109), which is 3 slots away from slot 0 (1106), at the time when the PDCCH (1101) is received.

According to one embodiment, in the example of FIG. 12, the terminal may monitor the PDCCH (1201) to obtain DCI format 0_1, and may obtain scheduling information and CSI request information for the PUSCH (1205) from the obtained DCI format 0_1. The terminal may obtain resource information for the CSI-RS (1202) to be measured from the received CSI request indicator.

An example of FIG. 12 shows an example in which the offset value for the aforementioned CSI-RS is set to X=1. In this case, the terminal can receive the CSI-RS (1202) in a slot (e.g., slot 0 (1206) of FIG. 13) in which the DCI format 0_1 that triggers the aperiodic CSI report is received, and the terminal can report the CSI information measured with the received CSI-RS to the base station through the PUSCH (1205).

Below, we will specifically explain the bandwidth part (BWP) settings in a 5G communication system.

Figure 13 is a diagram illustrating an example of settings for a bandwidth part in a 5G communication system.

Referring to FIG. 13, a UE bandwidth (1400) according to one embodiment may be set to two bandwidth parts, that is, bandwidth part #1 (BWP#1) (1301) and bandwidth part #2 (BWP#2) (1302). A base station may set one or more bandwidth parts to a UE, and may set at least some of the information included in [Table 33] for each bandwidth part.

At least some of the information included in [Table 33] may be transmitted or set by the base station to the terminal via upper layer signaling (e.g., RRC (Radio Resource Control) signaling). At least one bandwidth part among one or more configured bandwidth parts may be activated. Whether or not the configured bandwidth part is activated may be semi-statically transmitted from the base station to the terminal via RRC signaling or dynamically transmitted via DCI (Downlink Control Information).

According to one embodiment, a terminal before RRC (Radio Resource Control) connection can be configured with an initial bandwidth part (Initial BWP) for initial access from a base station through a Master Information Block (MIB). For example, the terminal can receive, through the MIB in the initial access phase, configuration information about a control region (Control Resource Set, CORESET) and a search space on which a PDCCH (Physical Downlink Control Channel) can be transmitted for receiving system information (e.g., Remaining System Information; RMSI or System Information Block 1; SIB1) required for initial access.

According to one embodiment, the control region and search space set by the MIB may each be regarded as or identified as identifier (ID) 0. The base station may notify or instruct the terminal of configuration information such as frequency allocation information, time allocation information, and/or numerology for the control region #0 through the MIB. In addition, the base station may notify or instruct the terminal of configuration information for the monitoring period and occasion for the control region #0, that is, configuration information for the search space #0, through the MIB. The terminal may regard or identify the frequency region set as the control region #0 obtained 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 or identified as 0.

The settings for the bandwidth part supported by 5G can be used for various purposes.

According to one embodiment, when the bandwidth supported by the terminal is smaller than the system bandwidth, data transmission and/or reception can be supported through bandwidth part setting. For example, the base station can set the frequency position of the bandwidth part (e.g., setting information 2) to the terminal, thereby allowing the terminal to transmit and/or receive data at a specific frequency position within the system bandwidth.

In one embodiment, the base station may set multiple bandwidth parts to the terminal for the purpose of supporting different numerologies. For example, in order to support both transmission and/or reception of data using a subcarrier spacing of 15 kHz and a subcarrier spacing of 30 kHz for a given terminal, the two bandwidth parts may be set with subcarrier spacings of 15 kHz and 30 kHz, respectively. The different bandwidth parts may be frequency division multiplexed, and when data is to be transmitted and received at a specific subcarrier spacing, the bandwidth part set with the specific subcarrier spacing may be activated.

According to one embodiment, for the purpose of reducing power consumption of the terminal, the base station may set bandwidth parts having different sizes of bandwidths for the terminal. For example, if the terminal supports a very large bandwidth, for example, a bandwidth of 100 MHz, and always transmits and receives data with a bandwidth of 100 MHz, very large power consumption may occur. In particular, in a situation where there is no traffic, performing monitoring for an unnecessary downlink control channel with a large bandwidth of 100 MHz 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 with 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 may perform a monitoring operation in the bandwidth part of 20 MHz, and when data is generated, may transmit and receive data in the bandwidth part of 100 MHz according to the instructions of the base station.

According to one embodiment, in a method for setting a bandwidth part, terminals before an RRC connection can receive setting information for an initial bandwidth part through a MIB (Master Information Block) in an initial access stage. For example, the terminal can receive a control resource set (CORESET) for a downlink control channel on which a DCI (Downlink Control Information) for scheduling a SIB (System Information Block) can be transmitted from an MIB of a PBCH (Physical Broadcast Channel). The bandwidth of the control area set by the MIB can be regarded or identified as the initial bandwidth part, and the terminal can receive a PDSCH (Physical Downlink Shared Channel) on which the SIB is transmitted through the set initial bandwidth part. In addition to the purpose of receiving the SIB, the initial bandwidth part can also be utilized for other system information (OSI), paging, and/or random access.

According to one embodiment, if more than one bandwidth part is set for a terminal (in case that), the base station may instruct the terminal to change the bandwidth part by using the Bandwidth Part Indicator field in the DCI. For example, referring to FIG. 3, if the currently activated bandwidth part of the terminal is Bandwidth Part #1 (301), the base station may instruct the terminal to Bandwidth Part #2 (302) by using the Bandwidth Part Indicator field in the DCI, and the terminal may perform a bandwidth part change to Bandwidth Part #2 (302) indicated by the Bandwidth Part Indicator field in the received DCI.

According to one embodiment, since a DCI-based bandwidth part change can be indicated by a DCI scheduling a PDSCH or a PUSCH (Physical Uplink Shared Channel), a terminal should be able to perform reception or transmission of a PDSCH or a PUSCH scheduled by the DCI without difficulty in the changed bandwidth part when receiving a bandwidth part change request (in case that). In order to perform transmission and/or reception of data in the changed bandwidth part, the standard specifies a requirement for a delay time (T_BWP) required when changing a bandwidth part. For example, it can be defined as in [Table 34].

According to one embodiment, the requirement for bandwidth part change delay time may support or require type 1 or type 2 depending on the capability of the terminal. The terminal may report to the base station the type of bandwidth part delay time that it can support.

According to one embodiment, based on a requirement for a bandwidth part change delay time, when a terminal receives a DCI including a bandwidth part change indicator in slot n, the terminal can complete or perform a change to a new bandwidth part indicated by the bandwidth part change indicator no later than slot n+T_BWP, and the terminal can perform transmission and reception for a data channel scheduled by the DCI in the changed new bandwidth part.

According to one embodiment, when the base station wants to schedule a data channel with a new bandwidth part, the base station may determine time domain resource allocation for the data channel based on the bandwidth part change delay time (T_BWP) of the terminal. That is, when the base station schedules the data channel with a new bandwidth part, the base station may schedule the data channel after the bandwidth part change delay time when determining time domain resource allocation for the data channel. Accordingly, the terminal may not expect that the DCI indicating the bandwidth part change indicates a slot offset (K0 or K2) value smaller than the bandwidth part change delay time (T_BWP).

In one embodiment, if (in case that) the terminal receives DCI indicating a bandwidth part change (e.g., DCI format 1_1 or 0_1), the terminal may not perform any transmission or reception during a time period corresponding to a third symbol of a slot in which a PDCCH including the DCI is received to a start point of the slot indicated by the slot offset (K0 or K2) value. For example, the slot offset (K0 or K2) may be indicated by a time domain resource allocation indicator field in the DCI.

For example, if a terminal receives a DCI indicating a bandwidth part change in slot n and the slot offset value indicated by the DCI is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol before slot n+K (e.g., the last symbol of slot n+K-1).

Below, we will explain how to set transmission and reception related parameters for each bandwidth part in 5G.

According to one embodiment, the terminal may be configured with one or more bandwidth parts from the base station, and may additionally be configured with parameters (e.g., configuration information related to uplink/downlink data channels and control channels, etc.) to be used for transmission and/or reception of signals for each configured bandwidth part. For example, referring to FIG. 13, when the terminal is configured with bandwidth part #1 (1301) and bandwidth part #2 (1302), the terminal may be configured with transmission/reception parameter #1 for bandwidth part #1 (1301), and may be configured with transmission/reception parameter #2 for bandwidth part #2 (1302). When bandwidth part #1 (1301) is activated, the terminal can transmit and/or receive a signal with the base station based on transmission/reception parameter #1, and when bandwidth part #2 (1302) is activated, the terminal can transmit and/or receive a signal with the base station based on transmission/reception parameter #2.

For example, at least some of the parameters included in [Table 35] to [Table 36] can be set from the base station to the terminal.

First, with regard to the uplink bandwidth part, the base station can set at least some of the information included in [Table 35] to the terminal.

Referring to [Table 35], the terminal can be configured with cell-specific (or cell common or common) transmission-related parameters (e.g., parameters related to a Random Access Channel (RACH), a Physical Uplink Control Channel (PUCCH), and/or a Physical Uplink Shared Channel)) from the base station (corresponding to BWP-UplinkCommon). In addition, the terminal can be configured with terminal-specific (or dedicated) transmission-related parameters (e.g., parameters related to a PUCCH, a PUSCH, a Configured Grant PUSCH, and/or a Sounding Reference Signal (SRS)) from the base station (e.g., BWP-UplinkDedicated).

With respect to the downlink bandwidth part, the base station may set at least some of the information included in [Table 36] to the terminal.

According to [Table 36], the terminal can be configured with cell-specific (or cell common or common) reception-related parameters (e.g., parameters related to a downlink control channel (PDCCH), a downlink data channel (Physical Downlink Shared Channel)) from the base station (e.g., BWP-DownlinkCommon). In addition, the terminal can be configured with terminal-specific (or dedicated) reception-related parameters (e.g., parameters related to PDCCH, PDSCH, semi-persistent scheduled PDSCH, and/or radio link monitoring (RLM)) from the base station (e.g., BWP-UplinkDedicated).

Below, we will specifically describe DRX (Discontinuous Reception) settings in a 5G communication system.

Figure 14 is a diagram explaining DRX (Discontinuous Reception).

Referring to FIG. 14, DRX can be referred to as an operation in which a terminal using a service discontinuously receives data in an RRC Connected state in which a wireless link is established between the base station and the terminal. When DRX is applied, the terminal can turn on the receiver at a specific point in time to monitor the control channel, and turn off the receiver if no data is received for a certain period of time to reduce the power consumption of the terminal. The DRX operation can be controlled by a MAC layer device based on various parameters and timers.

Referring to FIG. 14, the active time (1405) may be referred to as the time when the terminal wakes up every DRX cycle and monitors the PDCCH. The active time (1405) may 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

According to one embodiment, drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, and/or ra-ContentionResolutionTimer are timers whose values are set by the base station and have a function of setting the terminal to monitor the PDCCH when a specified condition is satisfied. For example, the timers can control the terminal to monitor the PDCCH when a specified condition is satisfied.

For example, drx-onDurationTimer (1415) may be a parameter for setting a minimum time for which the terminal stays awake in a DRX cycle. For example, drx-InactivityTimer (1420) may be a parameter for setting an additional time for which the terminal stays awake when receiving (1430) a PDCCH indicating new uplink transmission or downlink transmission. For example, drx-RetransmissionTimerDL may be a parameter for setting a maximum time for which the terminal stays awake to receive a downlink retransmission in a downlink HARQ procedure. For example, drx-RetransmissionTimerUL may be a parameter for setting a maximum time for which the terminal stays awake to receive an uplink retransmission grant in an uplink HARQ procedure.

For example, drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, and drx-RetransmissionTimerUL can be set as time, number of subframes, and/or number of slots. ra-ContentionResolutionTimer can be a parameter for monitoring PDCCH in random access procedure.

According to one embodiment, the inActive time (1410) may be a time set not to monitor PDCCH during a DRX operation and/or a time set not to receive PDCCH, and the remaining time excluding the Active time (1405) from the entire time of performing the DRX operation may correspond to the inActive time (1410). If the terminal does not monitor the PDCCH during the Active time (1405), it may enter a sleep or inActive state to reduce power consumption.

According to one embodiment, a DRX cycle may be referred to as a period during which a terminal wakes up and monitors a PDCCH. That is, it may be referred to as a period during which a time interval or on duration occurs after the terminal monitors a PDCCH until it monitors the next PDCCH. There are two types of DRX cycles: a short DRX cycle and a long DRX cycle. A short DRX cycle may be applied as an option.

According to one embodiment, the Long DRX cycle (1425) may be a longer cycle among two DRX cycles set in the terminal. While operating in Long DRX, the terminal may start drx-onDurationTimer (1415) again at a point in time when the Long DRX cycle (1425) has elapsed from the start point (e.g., start symbol) of drx-onDurationTimer (1415). As another example, when the terminal operates in Long DRX cycle (1425), the terminal may start drx-onDurationTimer (1415) in a slot after drx-SlotOffset in a subframe satisfying [Mathematical Formula 2] below. For example, drx-SlotOffset may be referred to as a delay before starting drx-onDurationTimer (1415). For example, drx-SlotOffset may be set to time, the number of slots, etc.

drx-LongCycleStartOffset can include Long DRX cycle (1525) and drx-StartOffset, and drx-LongCycleStartOffset can be used to define a subframe to start Long DRX cycle (1425). For example, drx-LongCycleStartOffset can be set to time, number of subframes, and/or number of slots.

According to one embodiment, the Short DRX cycle may be a shorter cycle among two DRX cycles defined in the UE. For example, the UE may operate in the Long DRX cycle (1425) and, when a certain event, such as a PDCCH indicating a new uplink transmission or downlink transmission is received (1430) during the Active time (1405), the UE may start or restart the drx-InactivityTimer (1420). For example, the UE may operate in the short DRX cycle if (in case that) the drx-InactivityTimer (1420) expires or the UE receives a DRX command MAC CE.

For example, in FIG. 14, the terminal can start drx-ShortCycleTimer at the expiration time of the previous drx-onDurationTimer (1415) or drx-InactivityTimer (1420), and operate in a short DRX cycle until drx-ShortCycleTimer expires.

According to one embodiment, when the terminal receives (1430) a PDCCH indicating a new uplink transmission or downlink transmission, the terminal may extend the Active Time (1405) or delay the arrival of the InActive Time (1410) in anticipation of additional uplink transmission or downlink transmission in the future. While operating in short DRX, the terminal starts drx-onDurationTimer (1415) again at a point in time when the short DRX cycle has elapsed from the start point of the previous on duration. Thereafter, when drx-ShortCycleTimer expires, the terminal may operate in the Long DRX cycle (1425) again.

According to one embodiment, when the terminal operates in Short DRX cycle, the terminal may start drx-onDurationTimer (1415) after drx-SlotOffset in a subframe satisfying [Mathematical Formula 3] below. For example, drx-SlotOffset may be referred to as a delay before starting drx-onDurationTimer (1415). For example, drx-SlotOffset may be set to time, number of slots, etc.

For example, drx-ShortCycle and drx-StartOffset can be used to define the subframe to start the Short DRX cycle. For example, drx-ShortCycle and drx-StartOffset can be set to time, number of subframes, and/or number of slots.

According to one embodiment, the terminal can reduce power consumption of the terminal by performing a DRX operation. However, even if the terminal performs the DRX operation, the terminal may not always receive a PDCCH related to the terminal at the Active Time (1405). Therefore, in one embodiment of the present disclosure, a signal for controlling the operation of the terminal can be provided in order to save power of the terminal more efficiently.

As described above, the 5G system may support ultra-wide bandwidth signal transmission and reception or utilize spatial multiplexing methods using multiple transmit/receive antennas to achieve ultra-high-speed data services reaching several Gbps, while supporting various power saving modes to reduce power consumption of terminals.

Meanwhile, the base station may also experience excessive power consumption. For example, the number of power amplifiers (PA) required may increase in proportion to the number of transmission antennas equipped in the base station or terminal. The maximum output of the base station and terminal depends on the characteristics of the PA, and the maximum output of the base station generally varies depending on the cell size covered by the base station. The maximum output can usually be expressed in dBm. The maximum output of the terminal is usually 23 dBm or 26 dBm.

As an example of a commercial 5G base station, the base station can be equipped with 64 transmit antennas and corresponding 64 power amplifiers in a 3.5 GHz frequency band and operate with a bandwidth of 100 MHz. As a result, the energy consumption of the base station increases in proportion to the output of the power amplifier and the operating time of the power amplifier. Compared to an LTE base station, a 5G base station has a relatively high operating frequency band, so it is characterized by a wide bandwidth and many transmit antennas. The feature of including a relatively large number of transmit antennas in the base station has the effect of increasing the data rate, but incurs the cost of increasing the energy consumption of the base station. Therefore, the more base stations there are in a mobile communications network, the greater the energy consumption of the entire mobile communications network.

As described above, the energy consumption of a base station is largely dependent on the operation of the power amplifier. Since the power amplifier is involved in the transmission operation of the base station, the downlink (DL) transmission operation of the base station is highly related to the energy consumption of the base station. The uplink (UL) reception operation of the base station does not account for a relatively large proportion of the energy consumption of the base station. The physical channel and physical signal transmitted by the base station in the downlink may include at least one of the following.

- PDSCH (Physical Downlink Shared Channel): A downlink data channel that contains data to be transmitted to one or more terminals.

- PDCCH (Physical Downlink Control Channel): A downlink control channel that includes scheduling information for PDSCH and PUSCH (Physical Uplink Control Channel). Alternatively, control information such as slot format and power control command can be transmitted only with PDCCH without PDSCH or PUSCH to be scheduled. The scheduling information includes resource information to which PDSCH or PUSCH is mapped, information related to HARQ (hybrid automatic repeat request), power control information, etc.

- PBCH (Physical Broadcast Channel): A downlink broadcast channel that provides MIB (Master Information Block), which is essential system information required for transmission and reception of data channels and control channels of terminals.

- PSS (Primary Synchronization Signal): This signal serves as the basis for DL time/frequency synchronization and provides some cell ID information.

- SSS (Secondary Synchronization Signal): A signal that serves as a basis for DL time and/or frequency (hereinafter referred to as time/frequency) synchronization and provides some remaining information such as cell ID.

- DM-RS (Demodulation Reference Signal): Reference signal for channel estimation of terminals for each of PDSCH, PDCCH, and PBCH.

- CSI-RS (Channel-state Information Reference Signal): Downlink signal that serves as a basis for measuring the terminal's downlink channel status.

- PT-RS(Phase-tracking Reference Signal): Downlink signal for phase tracking

According to one embodiment, from the perspective of base station energy saving, when the base station stops the downlink transmission operation, the power amplifier operation is stopped accordingly, so the base station energy saving effect can be increased, and the operation of the remaining base station devices such as the baseband device as well as the power amplifier can also be reduced, so that additional energy saving is possible. Similarly, even if the uplink reception operation occupies a relatively small proportion of the total energy consumption of the base station, the base station can obtain an additional energy saving effect if the uplink reception operation can be stopped.

According to one embodiment, the downlink transmission operation of the base station may basically depend on the amount of downlink traffic. For example, if there is no data to be transmitted to the terminal in the downlink, the base station does not need to transmit the PDSCH or the PDCCH for scheduling the PDSCH. Or, if the transmission can be temporarily postponed for reasons such as the data being insensitive to transmission delay, the base station may not transmit the PDSCH or/and the PDCCH.

In contrast, physical channels and physical signals such as PSS, SSS, PBCH, and/or CSI-RS have the characteristic of being repeatedly transmitted at a predetermined promised cycle regardless of data transmission to the terminal. Therefore, even if the terminal does not receive data, it can continuously update downlink time/frequency synchronization, downlink channel status, and/or radio link quality, etc. That is, the primary synchronization signal (PSS), secondary synchronization signal (SSS), PBCH, and/or CSI-RS may necessarily need to be transmitted in the downlink regardless of downlink data traffic, and downlink transmission causes base station energy consumption. Therefore, base station energy can be saved by controlling the transmission of signals unrelated to (or with low relevance to) data traffic to occur less frequently.

The energy saving effect of a base station can be maximized by stopping or minimizing the operation of the base station's power amplifier and related RF (radio frequency) devices, baseband devices, etc. during the time period when the base station is not performing downlink transmission through two base station energy saving methods.

As another method for saving energy, the base station can save energy consumption by switching off some of the antennas or power amplifiers of the base station (hereinafter, 'Base Station Energy Saving Method 2'). In this case, as a countermeasure to the energy saving effect of the base station, adverse effects such as a decrease in cell coverage or a decrease in throughput may occur. For example, if a base station equipped with 64 transmit antennas and corresponding 64 power amplifiers in the 3.5 GHz frequency band as described above and operating with a bandwidth of 100 MHz activates only 4 transmit antennas and 4 power amplifiers and switches off the rest during a designated time period for base station energy saving, the base station energy consumption during the designated time period can be reduced to about 1/16 (=4/64). However, the base station may have difficulty achieving cell coverage and throughput assuming the existing 64 antennas and power amplifiers due to a decrease in maximum transmission power and a decrease in beamforming gain.

According to one embodiment, the base station energy saving methods can be reclassified into three types. A base station energy saving method in the frequency domain that adjusts the size of a BWP according to the traffic of the base station, a base station energy saving method in the space domain that adaptively reduces the number of antenna ports, and/or a base station energy saving method in the time domain that adjusts the cycle of CSI-RS, SSB, and/or DRX. These three types of base station energy saving methods are used alone or in combination according to the characteristics of the base station such as base station traffic or coverage, and the change information must be shared with the terminal.

As a result, in situations where changed information or energy saving modes for energy saving are shared with terminals, the impact on energy-consuming technologies such as existing carrier aggregation (CA)/dual connectivity (DC), PDSCH/PUSCH/PUCCH repetition, and/or mTRP (multi transmission and reception point) should also be considered.

The base station energy saving method proposed in the present disclosure is explained through the following examples.

In one embodiment, for base station energy saving, a method is described in which a base station performs an energy saving operation of the base station after all traffic within the base station is consumed.

FIG. 15 is a diagram illustrating a method for a base station to deactivate the base station to a terminal to save base station energy according to one embodiment.

Referring to FIG. 15, a time domain according to an embodiment may be divided into an active time (or, normal mode) (1510) in which a base station is active and an inactive time (or, network energy saving mode) (1520) in which it is inactive. For example, a base station in an active time (1510) may transmit and/or receive data (1530) according to traffic of a terminal. When all traffic within the base station is exhausted, the base station may switch to a sleep mode (or energy saving mode) if there is no traffic within the base station in order to save energy. Accordingly, the base station may gradually switch to a sleep mode (1550) by turning off some of the antennas of the base station or controlling the bandwidth and/or the base station transmission power when it determines that it is no longer meaningful to be active and consume power.

However, the base station can notify the terminals connected to the base station of the instruction to deactivate the base station when the base station is switched to the power saving mode. The instruction to deactivate the base station can be signaled using RRC/MAC-CE or DCI, but the example below is explained based on DCI signaling (1540) as a representative example.

FIG. 16 is a diagram illustrating signaling between a base station and a terminal for a method in which a base station instructs a terminal to deactivate the base station to save base station energy, according to one embodiment.

Referring to FIG. 16, if it is determined that all traffic within a base station is exhausted and the base station is consuming meaningless power according to an embodiment, the base station may instruct connected terminals within the base station to switch to a power-saving mode via a cell deactivate indication (1610). A terminal that has received a cell deactivate indication may release an RRC connection or perform a handover or base station reselection. Accordingly, the terminal may perform an RRC connection release or base station reselection by itself through the cell deactivate indication (1610). For example, the cell deactivate indication (1610) may simply include a designated field value (e.g., 0 or 1) to indicate to the terminal that the base station is to be deactivated, and the cell deactivate indication (1610) may include an information element (IE) that instructs the terminal not only whether to deactivate the base station but also whether to release an RRC and/or whether to reselect a base station.

According to one embodiment, in the case of RRC connection release, the cell deactivation indication (1610) may be sufficient to simply notify that the base station is deactivated with 1-bit information, and a cell specific message may be efficient so that all terminals in the cell can receive it. However, the present invention is not limited thereto, and the cell deactivation indication (1610) may also be notified or instructed by a UE or group specific message. When a terminal receives a message notifying or instructing the cell deactivation indication (in case that), the terminal performs an RRC connection release or reselects a base station at its own discretion.

According to one embodiment, in case of handover or base station reselection, it can be an RRCRelease message, and it can be a message that triggers handover or base station reselection, so the message can be transmitted based on multi bits for triggering various operations. Since the operation can be different for each terminal, a UE or group specific message can be efficient, and since a base station that will be deactivated soon does not need to consider additional operations of the terminals, the operation of the terminals can be triggered at once with a cell specific message.

According to one embodiment, a terminal receiving DCI performs an operation according to the instruction, and may transmit an ACK (acknowledgement)/NACK (negative acknowledgement) (1620) through the received DCI before performing the operation. If (in case that) the terminal does not send an ACK/NACK, the base station can deactivate the base station regardless of whether the terminal properly received the DCI. If the base station is deactivated regardless of whether the DCI is received, the terminal will recognize that the base station connection is disconnected and perform a connection to another base station. If the terminal sends an ACK/NACK, the base station can deactivate the base station after receiving the ACK, and if there is a terminal that has not sent an ACK or a terminal that has sent a NACK in the base station, the base station can postpone the deactivation of the base station considering the status of the terminals. In addition, if the terminal sends an ACK/NACK for the DCI, the base station can identify that there is new Uplink data that the terminal wants to transmit, and may not perform cell deactivation in order to receive the data transmitted by the terminal. That is, the ACK/NACK for the DCI transmitted by the terminal may include information on whether the cell is deactivated. In addition, the base station may trigger a period in which the base station can send an ACK/NACK after transmitting the DCI, considering the received ACK/NACK. For example, the base station may adjust a time period in which the terminal can transmit an ACK/NACK based on the received ACK/NACK.

FIG. 17 is a diagram explaining a method of deactivating a base station using a base station deactivation timer for a terminal to save base station energy according to one embodiment.

Referring to FIG. 17, according to an embodiment, a base station instructs or notifies terminals of a base station inactivity period through DCI (1720) when all data transmission and reception is completed according to traffic of terminals within the base station during an activation time (1710). For example, the base station can inform terminals that there are candidates for values defined in advance in RRC as in [Table 37] and which value to use in DCI.

Alternatively, the base station can trigger a predefined fixed value using only 1 bit. For example, the base station can transmit a value having 1 bit to the terminal, and the terminal can identify the predefined fixed value based on the value having 1 bit received from the base station.

After DCI (1720) is transmitted, the base station can start the timer specified in (1720) and allows ACK or NACK transmission from the terminal during the time period from the start of the specified timer to the expiration. If ACK or NACK does not arrive from any terminal within the time period, the base station performs ramp-down (1740) as it is and enters the inactive period (1750). The following embodiments will be described based on FIG. 17. Hereinafter, FIG. 18 describes an embodiment regarding the operation of the terminal when uplink traffic of the terminal occurs during the base station inactive period of FIG. 17.

FIG. 18 is a diagram illustrating the operation of a base station in case that the base station receives a scheduling request for uplink traffic of a terminal during a base station inactivity period according to one embodiment.

According to one embodiment, if deactivation of the base station is indicated from the base station via DCI (1820) during the activation time (1810) of the base station, a deactivation timer (1830) may be indicated. If uplink traffic of the terminal occurs during the time period from when the deactivation timer starts to when it expires (in case that), the terminal may send a scheduling request (SR) (1840) to the base station. However, in the case where the terminal can send the SR during the base station deactivation period, there may be two situations: the base station allowed the terminal to transmit the SR during the time period or the terminal did not properly receive the DCI.

In one embodiment, if the base station is allowed to transmit SR during the time period, when the base station receives the SR, the base station may postpone deactivation and receive data on uplink traffic of the terminal that sent the SR. In this case, the base station may be set to an additional activation time (1850) (or, extended active time) for reception. Other terminals may determine that the base station is already deactivated and may disconnect from the base station or perform a handover or base station reselection operation to another base station. As another example, other terminals may be instructed by the base station to deactivate the base station and continue to maintain the state.

In one embodiment, when the terminal fails to properly receive the DCI, the SR of the terminal is not permitted, so the transmission of the SR depends on the setting of the base station, and the base station may operate in the same manner as if the base station were permitted to transmit the SR during the corresponding section, or the base station may ignore the SR of the terminal. If the base station ignores the SR of the terminal, the terminal determines that no response to the SR has arrived, and performs a handover to another base station or retransmits the SR after reselecting the base station.

Below, the operation of a terminal is described when uplink traffic of the terminal occurs during a period when the base station is inactive in a system subsequent to a 5G system (e.g., a 6G system).

In one embodiment, in a system other than a 5G system, the access and data transmission functions of a terminal may be separated by base station. The access and data transmission functions of a separated terminal may be conveniently referred to as an access cell and a data cell, respectively.

For example, an access cell can be responsible for access and mobility of a terminal by utilizing the wide coverage of a low-frequency band, and a data cell can be responsible for transmitting and/or receiving actual data of the terminal.

According to one embodiment, an access cell can also transmit and receive data to a terminal, but the function of transmitting and/or receiving data to a terminal may not be a primary function of the access cell. Since the access of the terminal is handled by the access cell, the terminal can perform a two-step cell selection of first selecting an access cell and then selecting a data cell connected to the access cell. Accordingly, data scheduling may be centrally performed in an access cell according to the traffic situation of multiple data cells, or may be performed in a distributed manner in each data cell.

In a system architecture (e.g., 6G system architecture), when uplink traffic of a terminal occurs during a period of base station inactivity, the terminal can transmit SR to an access cell or data cell. If the terminal sends ACK/NACK for a DCI that triggers base station inactivity, the NACK for the DCI can replace WUS. The following two drawings show signaling between a terminal and a base station when the terminal transmits SR to an access cell.

FIG. 19 is a diagram explaining an operation in which a terminal receives scheduling from a currently connected data cell when uplink traffic of a terminal occurs during a data cell inactivity period and SR is transmitted to an access cell according to an embodiment of the present invention.

For example, FIG. 19 may be referred to as a description of operations after a DCI (1820) is received and a base station deactivation timer (1830) is started while a reference UE (1910) is transmitting and receiving data from a serving data cell (1920).

In one embodiment, since the terminal was not allowed to transmit SR during the extended activation time (1830), the reference terminal (1910) may have uplink data and may transmit SR (1960) to the access cell (1940). The access cell (1940) receiving the SR (1960) may select a serving data cell (1920) that is already connected to the reference terminal (1910) as a data cell to process the received SR and instruct it to process the SR. For example, the access cell (1940) may activate and transmit SR (1965) to the serving data cell (1920).

According to one embodiment, the serving data cell (1920) that received the activation and SR (1965) may perform uplink scheduling (1980) for the reference UE (1910). Additionally, the reference UE (1910) may transmit an instruction (1970) to cancel the deactivate timer (1830) to other UEs (1950) to inform that the base station is not deactivated. The instruction (1970) to cancel the deactivate timer may have a structure similar to the DCI (1820).

FIG. 20 is a diagram explaining an operation in which a terminal receives scheduling from another activated data cell within an access cell when uplink traffic of the terminal is generated during a data cell inactivity period according to an embodiment of the present invention and SR is transmitted to an access cell.

For example, FIG. 20 may be an operation after a DCI (1820) is received and a base station deactivation timer (1830) is started while a reference UE (2010) is transmitting and receiving data from a serving data cell (2020). Since the UE is not permitted to transmit SR during the time period (1830) that expires after the deactivation timer is started, the reference UE (2010) may have uplink data and transmit SR (2060) to the access cell (2040).

According to one embodiment, an access cell (2040) that receives an SR (2060) may select another data cell (2030) that is activated within the access cell (2040) as a data cell to process the received SR and instruct the same to process the SR (2065). The access cell (2040) may simultaneously inform the reference UE (2010) of which data cell to receive data from, thereby helping the reference UE (2010) to perform a handover or change a data cell (2070). The neighboring data cell (2030) that receives the SR processing request (2065) may perform uplink scheduling (2080) for the reference UE. Other UEs (2050) may determine that the serving data cell (2020) is deactivated because they have not received instructions to change to another data cell or information about handover (2070) from the access cell, and other UEs (2050) may release the RRC connection or perform handover or cell reselection.

The following three drawings relate to signaling between a terminal and a base station when the terminal transmits SR to a data cell.

FIG. 21 is a diagram illustrating an operation in which a terminal receives scheduling from a previously connected data cell when uplink traffic of a terminal occurs during a data cell inactivity period and SR is transmitted to the data cell according to an embodiment of the present invention.

For example, FIG. 21 illustrates an operation after a deactivation timer (1830) of a base station is started by receiving DCI (1820) while a reference UE (2110) is transmitting and receiving data from a serving data cell (2120). Since the UE is not allowed to transmit SR during the time period (1830), the reference UE (2110) can have uplink data and transmit SR (2160) to the serving data cell (2120). The serving data cell (2120) that receives SR (2160) can perform uplink scheduling (2180) for the reference UE. Additionally, in order to inform other UEs (2150) that the base station is not deactivated, an instruction (2170) to cancel the base station deactivation timer corresponding to the time period (1830) can be transmitted. The instruction (2170) to cancel the base station inactivity timer may have a structure similar to the DCI (1820) of FIG. 18.

FIG. 22 is a diagram explaining an operation in which a terminal receives scheduling from another data cell within an access cell when uplink traffic of the terminal occurs during a data cell inactivity period according to an embodiment of the present invention and SR is transmitted to the data cell (in case that).

For example, FIG. 22 shows an operation after a base station deactivation timer (1830) starts when DCI (1820) is received while a reference UE (2210) is transmitting and receiving data in a serving data cell (2220). Since the UE is not allowed to transmit SR during the time period (1830), the reference UE (2210) can have uplink data and transmit SR (2260) to the data cell (2240). The serving data cell (2220) that receives SR (2260) determines that the base station deactivation that was initially decided is more energy efficient, and can send the received SR (2260) to the access cell (2240) (2265) and request that it be processed in another data cell. An access cell (2240) that receives an SR request (2265) can select another data cell (2230) activated within the access cell (2240) (e.g., a data cell that will process the received SR) and instruct it to process the SR (2266). The access cell (2240) can simultaneously inform a reference UE (2210) of which data cell to receive data from, thereby helping the reference UE (2210) to perform a handover or change data cells (2270). A neighboring data cell (2230) that receives an SR (2266) can perform uplink scheduling (2280) for the reference UE (2210). Since other UEs (2250) do not receive information (2270) indicating a handover or a change to another data cell from the access cell, they may think that the serving data cell (2220) is deactivated and release the RRC connection or perform a handover or cell reselection.

Figure 23 is a diagram illustrating an operation in which a terminal receives scheduling from another data cell within an access cell when uplink traffic of the terminal occurs during a data cell inactivity period and a wakeup signal (WUS) corresponding to SR is transmitted to data cells.

For example, FIG. 23 may be referenced as an operation after a base station deactivation timer (1830) is started as DCI (1820) is received while a reference UE (2310) is transmitting and receiving data from a serving data cell (2320). Since the UE is not allowed to transmit SR during the time period (1830), the reference UE (2310) may have uplink data and transmit a WUS (2360) corresponding to SR to the data cell (2340).

In one embodiment, each data cell may receive the WUS (2360) from the main receiver, or may receive the WUS (2360) from a low-power receiver separate from the main receiver. If (in case that) the data cell receives the WUS (2360) from the main receiver, the data cell receiving the WUS (2360) must be in an active state. On the other hand, in the case of a data cell having a separate low-power receiver, since the main receiver can receive the WUS (2360) in a power-saving state, the neighboring data cells do not need to be in an active state as described in FIGS. 20 and 22.

For example, similar to FIG. 23, among the data cells that received the WUS (2360), the serving data cell (2320) may transmit no response or NACK to the WUS (2360), and the neighboring data cell (2330) may transmit ACK or information about a base station change to the neighboring data cell (2330) in response to the WUS. When the base station change is performed, the reference UE (2310) is scheduled (2380) through the neighboring data cell (2330).

Below, the structure of the base station inactivity time is described.

The base station can trigger the base station inactivity time based on the DCI. At this time, the terminal can transmit the SR to the base station before the base station is completely inactive due to the uplink traffic of the terminal. The structure of the base station inactivity time in this embodiment is assumed as a case where the base station allows SR reception during a specified section and notifies other terminals in the base station that the base station is not inactive, as in FIG. 19 or FIG. 21. The structure of the base station inactivity time other than this will be a structure where SR and DCI for deactivation are possible in all sections, neither is possible, or only SR is possible.

FIG. 24 is a diagram of a base station inactivity time structure in an environment where a base station allows SR reception during the base station inactivity time according to one embodiment, and notifies other terminals within the base station that the base station is not inactivated in case that an SR is received.

Referring to FIG. 24, a deactivation timer (or, deactivate timer) (2410) according to an embodiment may be divided into an SR transmittable duration (or, a duration in which SR (2425) can be sent) (2420) and a duration in which signaling (2430) is performed to notify other terminals in the base station that the base station is not deactivated. Accordingly, a terminal may transmit SR (2425) if a specified condition is satisfied during the SR transmittable duration (SR Tx-able duration) (2420). For example, the specified condition may include a case in which uplink data to be transmitted by the terminal to the base station is generated. In addition, when the SR transmittable duration (2420) is over, the terminals may wait for or receive DCI (2430) and define an action to be taken after the deactivation time (2410). During the period excluding the SR transmittable period (2420) during the deactivation time (2410), the terminal does not need to perform PDCCH monitoring for all configured search spaces, and the terminal can check or identify whether there is a DCI for the cancellation of base station deactivation through PDCCH monitoring only for the search space corresponding to the cancellation of base station deactivation. In addition, during the period excluding the SR transmittable period (2420) during the deactivation time (2410), the base station can determine that the SR (2425) is not coming, and can ignore the SR even if the terminal sends it. During the period excluding the SR transmittable period during the deactivation time (2410), if the DCI is not received or is not properly received, the terminals can determine that the base station is deactivated and select another base station or switch to IDLE mode.

FIG. 25 is a drawing illustrating an example of a terminal transceiver device in a wireless communication system according to an embodiment of the present disclosure. For convenience of explanation, the drawing and description of devices not directly related to the present disclosure may be omitted.

Referring to FIG. 25, a terminal according to an embodiment may include a transmitter (2504) including an uplink transmission processing block (2501), a multiplexer (2502), a transmission RF block (2503), a receiver (2508) including a downlink reception processing block (2505), a demultiplexer (2506), a reception RF block (2507), and/or a control unit (2509). However, the terminal may further include configurations other than those illustrated in FIG. 25. In addition, the terminal may not include some of the configurations illustrated in FIG. 25.

According to one embodiment, the control unit (2509) can control each of the configuration blocks of the receiving unit (2508) for receiving a data channel or control channel transmitted by the base station and each of the configuration blocks of the transmitting unit (2504) for transmitting an uplink signal.

According to one embodiment, the uplink transmission processing block (2501) in the transmitter (2504) of the terminal may generate a signal to be transmitted by performing a process such as channel coding and/or modulation. The signal generated in the uplink transmission processing block (2501) may be multiplexed with another uplink signal by a multiplexer (2502), and then may be transmitted to a base station after signal processing in a transmission RF block (2503).

According to one embodiment, the terminal receiving unit (2508) can demultiplex a signal received from a base station and distribute it to each downlink receiving processing block. The downlink receiving processing block (2505) can perform a process such as demodulation and/or channel decoding on the downlink signal of the base station to obtain control information or data transmitted by the base station. The terminal receiving unit (2508) can support the operation of the control unit (2509) by applying the output result of the downlink receiving processing block to the control unit (2509).

Figure 26 is a block diagram illustrating an example of a configuration of a terminal according to one embodiment.

Referring to FIG. 26, a terminal according to an embodiment may include a processor (2630), a transceiver (2610), and/or a memory (2620). However, the components of the terminal are not limited to the above-described examples. For example, the terminal may include more or fewer components than the above-described components. In addition, the processor (2630), the transceiver (2610), and the memory (2620) may be implemented in the form of a single chip. The processor (2630) of the present disclosure may be replaced with a controller.

According to one embodiment, the transceiver (2610) of FIG. 26 may include the transmitter (2504) and the receiver (2508) of FIG. 25. In addition, the processor (2630) of FIG. 26 may include the control unit (2509) of FIG. 25.

According to one embodiment, the processor (2630) may control a series of processes by which the terminal may operate according to the embodiments of the present disclosure described above. For example, the processor (2630) may control components of the terminal to perform a transmission and reception method of the terminal depending on whether the base station mode is the base station energy saving mode or the base station normal mode. The processor (2630) may be one or more, and the processor (2630) may perform a transmission and reception operation of the terminal in a wireless communication system applying the carrier bundle of the present disclosure described above by executing a program stored in the memory (2620).

According to one embodiment, the transceiver (2610) can transmit and/or receive signals with the base station. The signals transmitted and received with the base station can include control information and data. The transceiver (2610) can be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, an RF receiver that low-noise amplifies the received signal and down-converts the frequency, etc. However, the transceiver (2610) is only one embodiment, and the components of the transceiver (2610) are not limited to the RF transmitter and the RF receiver. In addition, the transceiver (2610) can receive a signal through a wireless channel and output it to the processor (2630), and transmit a signal output from the processor (2630) through the wireless channel.

According to one embodiment, the memory (2620) can store programs and data required for the operation of the terminal. In addition, the memory (2620) can store control information or data included in signals transmitted and received by the terminal. The memory (2620) can be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there can be a plurality of memories (2620).

According to one embodiment, the memory (2620) may store a program for performing transmission and reception operations of the terminal depending on whether the base station mode of the embodiments of the present disclosure described above is a base station energy saving mode or a base station normal mode.

FIG. 27 is a block diagram showing an example of a configuration of a base station according to one embodiment of the present disclosure.

Referring to FIG. 27, the base station of the present disclosure may include a processor (2730), a transceiver (2710), and/or a memory (2720). However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than the components described above. In addition, the processor (2730), the transceiver (2710), and the memory (2720) may be implemented in the form of a single chip. The processor (2730) of the present disclosure may be replaced with a controller.

According to one embodiment, the processor (2730) may control a series of processes so that the base station can operate according to the embodiment of the present disclosure described above. For example, the processor (2730) may control components of the base station to perform a method for scheduling a terminal depending on whether the base station mode is the base station energy saving mode or the base station normal mode. The processor (2730) may be one or more, and the processor (2730) may perform the method for scheduling a terminal depending on whether the base station mode of the present disclosure described above is the base station energy saving mode or the base station normal mode by executing a program stored in the memory (2720).

According to one embodiment, the transceiver (2710) can transmit and/or receive signals with the terminal. The signals transmitted and received with the terminal can include control information and data. The transceiver (2710) can be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, an RF receiver that low-noise amplifies the received signal and down-converts the frequency, etc. However, the transceiver (2710) is only one embodiment, and the components of the transceiver (2710) are not limited to the RF transmitter and the RF receiver. In addition, the transceiver (2710) can receive a signal through a wireless channel and output it to the processor (2730), and transmit a signal output from the processor (2730) through the wireless channel.

According to one embodiment, the memory (2720) can store programs and data required for the operation of the base station. In addition, the memory (2720) can store control information or data included in signals transmitted and received by the base station. The memory (2720) can be configured as a storage medium or a combination of storage media, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, the memory (2720) can be plural. According to one embodiment, the memory (2720) can store a program for performing a method of scheduling a terminal depending on whether the base station mode of the embodiments of the present disclosure described above is a base station energy saving mode or a base station normal mode.

Although it has been described in FIG. 22 that the serving data cell (2220) transmits the received SR to the access cell (2240) (2260) and the access cell (2240) instructs the adjacent data cell (2230) to process the SR (2266), this is only an example. For example, the serving data cell (2220) may directly transmit the SR to the adjacent data cell (2230) without transmitting the SR to the access cell (2240). In this case, the serving data cell (2220) may identify the adjacent data cell (2230) to process the SR among at least one data cell that is activated based on receiving the SR from the reference terminal (2210), and the serving data cell (2220) may transmit the SR to the adjacent data cell (2230) and request (or instruct) the adjacent data cell to process the SR. For example, the adjacent data cell (2230) can allocate resources for UL data to the reference terminal (2210) based on the received SR. The adjacent data cell (2230) can receive the SR from the serving data cell (2220) and process the SR. When the adjacent data cell (2230) is requested to process the SR from the serving data cell (2220), the adjacent data cell (2230) can notify the access cell (2240) that it has been requested to process the SR. As another example, when the adjacent data cell (2230) is requested to process the SR from the serving data (2220), the adjacent data cell (2230) can notify the access cell (2240) that it has processed the SR. However, this is only an example, and the adjacent data cell (2230) may not notify the access cell (2240) of the information that it has been requested to process the SR. For example, a serving data cell (2220) may transmit a request for SR processing and transmit information to an access cell (2240) informing that it has requested SR processing from a neighboring data cell (2230).

In the specific embodiments of the present disclosure described above, the components included in the present disclosure are expressed in the singular or plural form according to the specific embodiments presented. However, the singular or plural expressions are selected to suit the presented situation for the convenience of explanation, and the present disclosure is not limited to the singular or plural components, and even if a component is expressed in the plural form, it may be composed of the singular form, or even if a component is expressed in the singular form, it may be composed of the plural form.

Meanwhile, the present specification and drawings have disclosed preferred embodiments of the present disclosure, and although specific terms have been used, they are only used in a general sense to easily explain the technical contents of the present disclosure and to help understand the disclosure, and are not intended to limit the scope of the present disclosure. In addition to the embodiments disclosed herein, it will be apparent to those skilled in the art to which the present disclosure pertains that other modified examples based on the technical idea of the present disclosure are possible. In addition, each of the above embodiments can be combined and operated as needed.

Meanwhile, although the detailed description of the present disclosure has described specific embodiments, it is obvious that 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, but should be determined not only by the scope of the claims described below, but also by equivalents of the scope of the claims.

Claims (15)

1. In a method performed by a UE (user equipment) in a wireless communication system,

   A step of camping on a second cell activated for data transmission among at least one cell associated with a first cell of a base station for random access;

   A step of receiving the data from the base station on the second cell; and

   A method comprising the step of receiving, from the base station, information indicating deactivation of the second cell on the second cell.
2. In claim 1,

   A method wherein the information indicating the deactivation of the second cell is received via at least one of a downlink control information (DCI), a medium access control (MAC) control element (CE), or a radio resource control (RRC) message.
3. In claim 1,

   A step of transmitting a SR (scheduling request) to the base station on the first cell or the second cell; and

   A method comprising the step of receiving information from the base station indicating cancellation of the deactivation on the second cell.
4. In claim 1,

   A step of transmitting a SR (scheduling request) to the base station on the first cell or the second cell; and

   A method comprising the step of receiving, from the base station, information for handover from the first cell to a third cell among the at least one cell.
5. In claim 1,

   A step of transmitting a scheduling request (SR) to the base station before the timer started based on the information instructing the deactivation expires; and

   A method comprising the step of transmitting, to the base station, uplink data associated with the SR during an activation period including a specified period of time after the timer expires.
6. In a wireless communication system, in the UE (user equipment),

   transceiver; and

   A controller coupled with the above transceiver,

   The above controller:

   Camping on a second cell that is activated for data transmission among at least one cell associated with the first cell of the base station for random access,

   From the above base station, the data is received on the second cell (on),

   A UE configured to receive, from the base station, information indicating deactivation of the second cell on the second cell.
7. In claim 6,

   The above controller:

   To the base station, transmit an SR (scheduling request) on the first cell or the second cell,

   A UE configured to receive, from the base station, information indicating cancellation of the deactivation on the second cell.
8. In claim 6,

   The above controller:

   To the base station, transmit an SR (scheduling request) on the first cell or the second cell,

   A UE configured to receive, from the base station, information for handover from the first cell to a third cell among the at least one cell.
9. In a method performed by a base station in a wireless communication system,

   A step of transmitting data to a UE (user equipment) on a second cell activated for data transmission among at least one cell associated with a first cell of the base station for random access; and

   A method comprising the step of transmitting, to the UE, information instructing deactivation of the second cell on the second cell.
10. In claim 9,

    A method wherein the information indicating the deactivation of the second cell is transmitted via at least one of a DCI (downlink control information), a MAC (medium access control) CE (control element), or an RRC (radio resource control) message.
11. In claim 9,

    A step of receiving a scheduling request (SR) from the UE on the first cell or the second cell; and

    A method comprising the step of transmitting, to the UE, information indicating cancellation of the deactivation on the second cell.
12. In claim 9,

    A step of receiving a scheduling request (SR) from the UE on the first cell or the second cell; and

    A method comprising the step of transmitting, to the UE, information for handover from the first cell to a third cell among the at least one cell.
13. In claim 9,

    A step of receiving a scheduling request (SR) from the UE before a timer started based on the information indicating the deactivation expires; and

    A method comprising the step of receiving, from the UE, uplink data associated with the SR during an activation period including a specified period of time after the timer expires.
14. In a wireless communication system, at a base station,

    transceiver; and

    A controller coupled with the above transceiver,

    The above controller:

    Transmitting data from a UE (user equipment) on a second cell that is activated for data transmission among at least one cell associated with the first cell of the base station for random access,

    A base station configured to transmit, to the UE, information instructing deactivation of the second cell on the second cell.
15. In claim 14,

    A base station, wherein the information indicating the deactivation of the second cell is transmitted via at least one of a DCI (downlink control information), a MAC (medium access control) CE (control element), or an RRC (radio resource control) message.

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