WO2020054025A1

WO2020054025A1 - User equipment and wireless communication method

Info

Publication number: WO2020054025A1
Application number: PCT/JP2018/034003
Authority: WO
Inventors: 一樹武田; 祐輝松村; 聡永田; リフェワン; ギョウリンコウ
Original assignee: 株式会社Ｎｔｔドコモ
Priority date: 2018-09-13
Filing date: 2018-09-13
Publication date: 2020-03-19

Abstract

In order to appropriately perform a beam recovery procedure, user equipment according to an aspect of the present disclosure comprises: a receiving unit that monitors a downlink control channel in a beam failure recovery (BFR) procedure; and a control unit that, upon detecting the downlink control channel in a range where a first search space corresponding to a first control resource set overlaps a second search space corresponding to a second control resource set that has been set for BFR, determines a search space in which the downlink control channel was transmitted, on the basis of a predetermined rule or downlink control information transmitted in the downlink control channel.

Description

User terminal and wireless communication method

The present disclosure relates to a user terminal and a wireless communication method in a next-generation mobile communication system.

In a UMTS (Universal Mobile Telecommunications System) network, long term evolution (LTE: Long Term Evolution) has been specified for the purpose of higher data rates and lower delays (Non-Patent Document 1). Also, LTE-A (LTE Advanced, LTE @ Rel. 10, 11, 12, 13) has been specified for the purpose of further increasing the capacity and sophistication of LTE (LTE @ Rel. 8, 9).

Succession system of LTE (for example, FRA (Future Radio Access), 5G (5th generation mobile communication system), 5G + (plus), NR (New Radio), NX (New radio access), FX (Future generation radio access), LTE Rel. 14 or 15 or later) are also being studied.

In the existing LTE system (LTE Rel. 8-13), monitoring of radio link quality (radio link monitoring (RLM: Radio Link Monitoring)) is performed. When a radio link failure (RLF: Radio @ Link @ Failure) is detected from the RLM, re-establishment of an RRC (Radio @ Resource @ Control) connection is requested to a user terminal (UE: User @ Equipment).

In NR, it is considered to detect a beam failure and perform a procedure for switching to another beam (which may be called a beam recovery (BR) procedure).

Also, in the NR, it is being studied to notify the UE of downlink control information using a control resource set (CORESET: Control REsource SET) which is a control channel allocation candidate area. A predetermined search space setting is associated with CORESET.

During the beam recovery procedure, monitoring of a downlink control channel (for example, PDCCH) using at least a RESET for the beam recovery procedure (a RESET for BFR) and a search space associated with the RESET is being considered. . On the other hand, in the BFR procedure, monitoring of the PDCCH using a search space associated with a coreset other than the coreset for the BFR may be considered. The search space associated with another coreset may be, for example, a search space associated with the coreset that was monitored prior to the BFR procedure.

However, when a plurality of search spaces are set in the BFR procedure, how to control monitoring of the PDCCH in the plurality of search spaces has not been sufficiently studied. If the monitoring of the PDCCH using the search space is not properly performed in the BFR procedure, the BFR procedure cannot be properly and successfully completed, and the communication throughput or the communication quality may be deteriorated.

Therefore, an object of the present disclosure is to provide a user terminal and a wireless communication method that can appropriately perform a beam recovery procedure.

A user terminal according to one aspect of the present disclosure includes a receiving unit that monitors a downlink control channel in a beam failure recovery (BFR) procedure, and a first search space corresponding to a first control resource set. If a downlink control channel is detected in a range where the second search space corresponding to the second control resource set set for BFR overlaps with a predetermined rule, the downlink control channel transmitted on the downlink control channel is detected. A control unit that determines a search space in which the downlink control channel has been transmitted, based on information.

According to one aspect of the present disclosure, a beam recovery procedure can be appropriately performed.

FIG. 1 is a diagram illustrating an example of a beam recovery procedure. FIG. 2 is a diagram illustrating an example where a plurality of control resource sets and search spaces are set. FIG. 3 is a diagram illustrating an example of a plurality of control resource sets and search space parameters. FIG. 4 is a diagram showing an example of the PDCCH detection operation according to the first example. FIG. 5 is a diagram showing another example of the PDCCH detection operation according to the first example. FIG. 6 is a diagram illustrating an example of a PDCCH detection operation according to the second example. FIG. 7 is a diagram illustrating an example of a schematic configuration of the wireless communication system according to the embodiment. FIG. 8 is a diagram illustrating an example of the entire configuration of the wireless base station according to the embodiment. FIG. 9 is a diagram illustrating an example of a functional configuration of the wireless base station according to the embodiment. FIG. 10 is a diagram illustrating an example of the entire configuration of the user terminal according to the embodiment. FIG. 11 is a diagram illustrating an example of a functional configuration of the user terminal according to the embodiment. FIG. 12 is a diagram illustrating an example of a hardware configuration of the radio base station and the user terminal according to the embodiment.

In NR, communication using beam forming (BF) is being studied. For example, a UE and / or a base station (for example, gNB (gNodeB)) transmits a beam (also referred to as a transmission beam or a Tx beam) used for transmitting a signal, or a beam used for receiving a signal (a reception beam, an Rx beam, or the like). May also be used.

In an environment where 用いる BF is used, radio link quality is likely to be degraded because it is susceptible to interference from obstacles. Radio link failure (RLF: Radio Link Failure) may frequently occur due to deterioration of the radio link quality. When RLF occurs, cell reconnection is required, so frequent occurrence of RLF causes deterioration of system throughput.

In NR, in order to suppress the occurrence of RLF, when the quality of a specific beam deteriorates, switching to another beam (beam recovery (BR: Beam @ Recovery), beam failure recovery (BFR: Beam @ Failure @ Recovery), Implementation of an L1 / L2 (Layer 1 / Layer 2) beam recovery procedure (which may be referred to as beam recovery) is being considered. The BFR procedure may be simply called BFR, or may be called a link recovery (LR: Link @ Recovery) procedure or simply LR.

FIG. 1 is a diagram showing an example of a beam recovery procedure. The number of beams and the like are merely examples, and are not limited thereto. In the initial state of FIG. 1 (step S101), the UE has received a downlink control channel (PDCCH: Physical {Downlink} Control} Channel) transmitted using two beams.

において In step S102, the UE cannot detect the PDCCH due to the interruption of the radio wave from the base station. Such interference may occur, for example, due to the effects of obstacles, fading, interference, etc. between the UE and the base station.

The UE detects a beam failure when a predetermined condition is satisfied. The base station may determine that the UE has detected a beam failure when there is no notification from the UE or when a predetermined signal (a beam recovery request in step S104) is received from the UE.

In step S103, the UE starts searching for a new candidate beam (new @ candidate @ beam) to be newly used for communication for beam recovery. Upon detecting the beam failure, the UE performs a measurement based on a preset downlink signal (which may be referred to as DL-RS (Reference Signal), BFR-RS, or the like) resource, and is desirable (for example, of good quality). One or more new candidate beams may be specified. In this example, one beam is specified as a new candidate beam.

The DL-RS resource (DL-RS resource) is associated with a resource and / or a port for a synchronization signal block (SSB: Synchronization Signal Block) or a channel state measurement RS (CSI-RS: Channel State Information RS). Is also good. The SSB may be called an SS / PBCH (Physical Broadcast Channel) block or the like.

The DL-RS includes a primary synchronization signal (PSS: Primary @ SS), a secondary synchronization signal (SSS: Secondary @ SS), a mobility reference signal (MRS: Mobility @ RS), a signal included in the SSB, a CSI-RS, a demodulation reference signal ( DMRS: Demodulation Reference Signal, at least one of beam-specific signals, or a signal configured by extending and / or changing these (for example, a signal configured by changing the density and / or period), Is also good. The DL-RS may be referred to as a new candidate beam detection signal.

In step S104, the UE that has identified the new candidate beam transmits a beam recovery request (BFRQ: Beam \ Failure \ Recovery \ reQuest). The beam recovery request may be called a beam recovery request signal, a beam failure recovery request signal, or the like.

The beam recovery request is transmitted using, for example, at least one of an uplink control channel (PUCCH: Physical Uplink Control Channel), a random access channel (PRACH: Physical Random Access Channel), and a UL grant-free PUSCH (Physical Uplink Shared Channel). You may.

The beam recovery request may include information on the new candidate beam specified in step S103. Resources for a beam recovery request may be associated with the new candidate beam. The beam information is notified using a beam index (BI: Beam @ Index), a port and / or a resource index of a predetermined reference signal (for example, a CSI-RS resource index (CRI)). Is also good.

In step S105, the base station that has detected the beam recovery request transmits a response signal to the beam recovery request (BFRQ) from the UE. The response signal may include reconfiguration information on one or a plurality of beams (for example, configuration information of a DL-RS resource). The response signal may be transmitted, for example, in a PDCCH UE common search space. In addition, the response signal is notified using a PDCCH (DCI) scrambled by a cyclic redundancy check (CRC: Cyclic Redundancy Check) by an identifier of the UE (for example, Cell-Radio RNTI (C-RNTI)). May be done. The UE may determine at least one of a transmit beam and a receive beam to use based on the beam reconfiguration information.

The UE may monitor the response signal based on at least one of a BFR control resource set (CORESET: Control REsource SET) and a BFR search space set.

Regarding the CB-BFR, when the UE receives the PDCCH corresponding to the C-RNTI for itself, it may be determined that the contention resolution is successful.

Regarding the process of step S105, a period for the UE to monitor a response (response) to the BFRQ from the base station (for example, gNB) may be set. The period may be called, for example, a gNB response window, a gNB window, a beam recovery request response window, or the like. The UE may retransmit BFRQ if there is no gNB response detected within the window period.

In step S106, the UE may transmit a message indicating that the beam reconfiguration has been completed to the base station. The message may be transmitted by, for example, the PUCCH or may be transmitted by the PUSCH.

Beam recovery success (BR success) may represent, for example, a case where the process reaches step S106. On the other hand, the beam recovery failure (BR @ failure) may indicate, for example, a case where no candidate beam has been identified in step S103.

Note that the numbers of these steps are merely numbers for explanation, and a plurality of steps may be put together or the order may be changed. Whether to perform BFR may be set in the UE using higher layer signaling.

Here, the upper layer signaling may be, for example, any of RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information, or a combination thereof.

The MAC signaling may use, for example, a MAC control element (MAC CE (Control Element)), a MAC PDU (Protocol Data Unit), or the like. The broadcast information includes, for example, a master information block (MIB: Master Information Block), a system information block (SIB: System Information Block), minimum system information (RMSI: Remaining Minimum System Information), and other system information (OSI: Other). System @ Information).

In the NR, CB-BFR (Contention-Based BFR), which is a BFR based on a collision-type random access (RA) procedure, and CF-BFR (Contention-Free BFR), which is a BFR based on a collision-free random access procedure, are used. Are being considered.

In CB-BFR, the UE may transmit a preamble randomly selected from one or more preambles (RA preamble, also referred to as a random access channel (PRACH: Physical Random Access Channel), RACH preamble, or the like). On the other hand, in CF-BFR, the UE may transmit a preamble assigned from the base station to the UE. In CB-BFR, the base station may assign the same preamble to multiple UEs. In CF-BFR, the base station may assign a preamble to each UE.

In CB-BFR, when a base station receives a certain preamble as a beam recovery request, the base station may not be able to specify which UE the preamble was transmitted to. The base station performs contention resolution based on a collision-type random access procedure (contention resolution) between the beam recovery request and the completion of the beam reconfiguration, thereby identifying the UE (e.g., cell-wireless RNTI ( C-RNTI: Cell-Radio @ RNTI)) can be specified.

The signal (eg, preamble) transmitted by the UE during the プリ RA procedure may be assumed to be a beam recovery request.

Regardless of CB-BFR or CF-BFR, information on PRACH resources (RA preamble) may be notified by, for example, higher layer signaling (RRC signaling). For example, the information may include information indicating a correspondence between the detected DL-RS (beam) and the PRACH resource, and a different PRACH resource may be associated with each DL-RS.

Beam failure detection may be performed at the MAC layer. Regarding CB-BFR, when the UE receives the PDCCH corresponding to the C-RNTI for itself, it may be determined that the contention resolution (contention resolution) is successful.

The RA parameters of CB-BFR and CF-BFR may be composed of the same parameter set. Different values may be set for the RA parameters of CB-BFR and CF-BFR, respectively. For example, the parameter indicating the length of time for monitoring the gNB response in the beam fault recovery response coreset after BFRQ (which may be referred to as “ResponseWindowSize-BFR”) may be applied only to CF-BFR. .

By the way, in NR, a control resource set (CORESET: Control RESET) is used to transmit a physical layer control signal (for example, downlink control information (DCI: Downlink Control Information)) from the base station to the UE. Is being considered.

$ CORESET is an allocation candidate area for a control channel (for example, PDCCH (Physical Downlink Control Channel)). The UE may receive the configuration information of the coreset (may be referred to as coreset configuration (coreset configuration) or coreset-config) from the base station. The UE can detect the physical layer control signal by monitoring the coreset set in the own terminal.

The CORESET setting may be notified by, for example, higher layer signaling, or may be represented by a predetermined RRC information element (which may be called “ControlResourceSet”).

The Coreset configuration mainly includes information on the resource-related configuration and the RS-related configuration of the PDCCH, and may include, for example, information on at least one of the following:
A CORESET identifier (CORESET ID (Identifier));
A scramble ID of a demodulation reference signal (DMRS) for the PDCCH,
Time duration (eg, 1, 2 or 3 symbols),
-Frequency-domain resource allocation (Frequency-domain Resource Allocation),
Mapping between control channel elements (CCE: Control Channel Element) and resource element groups (REG: Resource Element Group) (interleaved, non-interleaved);
・ REG bundle size,
Index of shift amount in case of interleaving,
A transmission configuration notification (TCI: Transmission Configuration Indication) state for the PDCCH,
Enable / disable the TCI field.

On the other hand, a search area and a search method of a PDCCH candidate (PDCCH @ candidates) are defined as a search space (SS: Search @ Space). The UE may receive search space configuration information (which may be referred to as search space configuration (search \ space \ configuration)) from the base station.

The search space setting may be notified to the UE by, for example, higher layer signaling (eg, RRC signaling) or may be represented by a predetermined RRC information element (which may be referred to as “SearchSpace”).

The search space configuration mainly includes information on monitoring-related configuration and decoding-related configuration of the PDCCH, and may include, for example, information on at least one of the following:
-Search space identifier (search space ID),
A CORRESET ID to which the search space setting relates,
A flag indicating whether it is a common search space (C-SS: Common SS) or a UE-specific search space (UE-SS: UE-specific SS);
The number of PDCCH candidates for each aggregation level,
・ Monitoring cycle,
Monitoring offset,
A monitoring pattern in the slot (eg a 14 bit bitmap).

UE monitors CORESET based on search space settings. In the description of the present disclosure, “monitor of CORESET” includes “monitor of search space (PDCCH candidate) associated with CORESET”, “monitor of downlink control channel (eg, PDCCH)”, and “monitoring of downlink control channel (eg, PDCCH). ), Blind decoding and / or detection ”.

The UE can determine the correspondence between the CORESET and the search space based on the CORESET $ ID included in the search space setting. One coreset may be associated with one or more search spaces.

モニタ It is being studied to monitor the response signal to the beam recovery request (BFRQ) in step S105 described in FIG. 1 by using the BFR coreset. The BFR CORESET may be set in the UE using a predetermined RRC information element (IE: Information @ Element) (which may be referred to as “CORESET-BFR”).

ネットワーク Further, the network (for example, a base station) may set a search space (for example, BFR-SS) corresponding to the coreset for BFR. The UE may monitor the PDCCH (response signal to the BFRQ) in the search space corresponding to the BFR coreset, and may determine that the BFR operation has been successful when the PDCCH is received.

By the way, in the NR, during the BFR procedure (for example, after transmitting the beam recovery request), it is considered that the PDCCH candidate is continuously monitored for the search space that was monitored before the transmission of the beam recovery request. Have been. That is, in the BFR procedure, after transmitting the PRACH for the BFRQ in the BFR procedure, the UE monitors the search space corresponding to another RESET (eg, for the non-BFR) in addition to the search space corresponding to the RESET for the BFR. It is possible to do.

However, when a plurality of search spaces are set, there is a case where ranges overlap (overlap) between different search spaces. For example, a case where the range of the BFR search space and another search space overlap may occur.

In such a case, if the UE detects a PDCCH (or a PDCCH candidate) in the overlapping range, it becomes impossible to determine which search space the detected PDCCH corresponds to. If it is not possible to determine whether the detected PDCCH is a BFR search space, the BFR procedure cannot be properly completed, and there is a possibility that communication throughput or communication quality may deteriorate.

Therefore, the present inventors have paid attention to the point that a plurality of search space ranges may overlap in the BFR procedure, and have conceived a UE operation when a PDCCH (or a PDCCH candidate) is detected in the search space overlap range. .

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. The wireless communication method according to each embodiment may be applied alone or in combination.

(First aspect)
In the first aspect, when a downlink control channel is detected in a range where a first search space corresponding to a first control resource set and a second search space corresponding to a second control resource set overlap, The search space in which the downlink control channel has been transmitted is determined based on a predefined rule.

In the following description, a case where the second search space (or the second control resource set) is a BFR search space (or a BFR control resource set) set for the BFR will be described as an example. . The first search space (or the first control resource set) may be a non-BFR search space set before the BFR procedure (for example, before transmitting the PRACH for BFRQ).

FIG. 2 shows a first search space (search space #A) corresponding to the first control resource set (CORESET # A) and a second search space corresponding to the second control resource set (CORESET # B). An example of setting with (search space #B) is shown.

Here, the same PRB set and the same number of symbols are set for CORRESET # A and CORRESET # B, and the same DCI format, the number of PDCCH candidates, the monitoring occasion (monitoring period, etc.) for search space #A and search space #B. Is set. The configuration and number of the control resource set and the search space to be set are not limited thereto. Three or more coresets and search spaces may be set.

FIG. 3 shows a search space #A (search space ID # 1) corresponding to CORESET #A (CORESET ID # 1), and a search space #B (search space ID #) corresponding to CORESET #B (CORESET ID # 2). An example of detailed parameters set in 2) is shown. The setting of the control resource set ID and the search space ID is not limited to this.

In FIG. 3, the same frequency region (for example, 6 RB × 8) and the same mapping pattern (for example, control channel element (CCE)) are used for RESET # A (CORE # ID # 1) and RESET # B (CORE # ID # 2). And resource element group (REG) mapping without interleaving), the same precoding granularity is applied. Further, a predetermined TCI state (for example, CSI-RS # 1) is set for CORRESET # A (CORESET @ ID # 1). Note that a configuration may be adopted in which the TCI state is not set (or the set value is ignored) in CORRES # B for BFR.

Also, for the search space #A (search space ID # 1) and the search space #B (search space ID # 2), the same monitoring occasion (for example, the first symbol of each slot) and the same search space type (for example, UE-specific) 2 shows a case where the same DCI format (for example, DCI @ format @ 1_1 or 0_1) is set. The number of PDCCH candidates for each search space #A (search space ID # 1) and search space #B (search space ID # 2) aggregation (AL) is partially overlapped.

Here, for search space #A (search space ID # 1), the number of PDCCH candidates in AL = 1, 2, 4, 8, 16 is set to {0, 4, 2, 1, 0}, and the search is performed. For space #B (search space ID # 2), the number of PDCCH candidates in AL = 1, 2, 4, 8, 16 is set to {0, 0, 2, 1, 1}.

For example, when the RS selected for BFR is CSI-RS # 1, PDCCH candidates corresponding to AL = 4, 8 are set redundantly in search space #A and search space #B. In this case, since the UE monitors PDCCH candidates for AL = 4 and 8 for search space #A and search space #B, the range of search space #A and search space #B partially overlaps. Become.

After transmitting BFRQ (for example, PRACH) in the BFR procedure, the UE monitors the PDCCH in the process of receiving the response signal. In this case, when the UE detects a PDCCH (or a PDCCH candidate) corresponding to AL = 4 or 8, whether or not the PDCCH corresponds to a PDCCH for BFR (or search space #A and search space #B) Which one of the two) may not be determined.

In the first aspect, when a PDCCH is received in a range where a plurality of search spaces (for example, the search space #A and the search space #B) overlap, the PDCCH received based on any of the following rules 1-3 Judge the corresponding search space. Thus, even when search spaces are set in duplicate, it is possible to control the BFR procedure by appropriately determining whether the detected PDCCH is for BFR. As a result, it is possible to suppress deterioration in communication throughput and communication quality.

<Rule 1>
According to rule 1, when a PDCCH that may have been transmitted by the BFR search space (BFR-SS) is detected, it is assumed that the PDCCH has been transmitted by the BFR-SS.

For example, if the UE receives the PDCCH in a range where the BFR search space (search space #B in FIG. 2) and another search space (search space #A in FIG. 2) overlap, the PDCCH in the search space #B It is determined that (BFR PDCCH) has been received (see FIG. 4). Then, the UE may determine that the response signal to the beam recovery request (BFRQ) has been successfully received, and may complete the BFR procedure.

The PDCCH may be subjected to CRC (Cyclic Redundancy Check) bit scrambling by a predetermined RNTI (Radio Network Temporary Identif). The predetermined RNTI may be, for example, a C-RNTI.

As described above, by using the PDCCH transmitted in the range where the search space overlaps as the PDCCH for BFR, the PDCCH for BFR can be transmitted using the entire search space for BFR. As a result, the UE can appropriately receive the PDCCH for BFR, so that the BFR procedure can be completed early.

<Rule 2>
According to rule 2, even when a PDCCH that may have been transmitted by the BFR search space (BFR-SS) is detected, the PDCCH is transmitted by a non-BFR-SS (or transmitted by a BFR-SS). Not be assumed).

For example, if the UE receives the PDCCH in a range where the BFR search space (search space #B in FIG. 2) and another search space (search space #A in FIG. 2) overlap, the PDCCH in the search space #A (PDCCH for non-BFR) is determined to be received (see FIG. 5). In this case, the UE may continue the BFR procedure without determining that the response signal to the beam recovery request (BFRQ) has been successfully received.

When transmitting a response signal to BFRQ using a PDCCH for BFR (for example, search space #B), the network (for example, a base station) transmits the response signal in a range that does not overlap with search space #A (for example, a monitoring occasion). Control.

For example, the base station may transmit the BFR PDCCH using a range in which search space #A and search space #B do not overlap (AL = 16 in FIG. 3). Alternatively, when the search space #A and the search space #B are set to have different periods or the like, control is performed such that a response signal to BFRQ is transmitted when only the search space #B is set.

The UE may assume that a response signal to BFRQ is transmitted in a range of search space #B that does not overlap with search space #A. For example, when receiving the PDCCH (PDCCH for BFR) in the range of search space #B that does not overlap with search space #A, the UE determines that the response signal to the beam recovery request (BFRQ) has been successfully received, The BFR procedure may be completed.

As described above, by using the PDCCH transmitted in the range where the search space overlaps as the non-BFR PDCCH, the network (for example, the base station) can perform the BFR procedure even during the BFR procedure in the same manner as in the case without the BFR procedure. The PDCCH can be scheduled.

<Rule 3>
According to rule 3, when a PDCCH that may have been transmitted by the BFR search space (BFR-SS) is detected, the PDCCH is included in the BFR-SS (search space #B) and the non-BFR-SS (search space #A). The UE determines which is transmitted.

For example, when the UE receives a PDCCH in a range in which a search space for BFR (search space #B in FIG. 2) and another search space (search space #A in FIG. 2) overlap, any of the PDCCHs may be searched. It autonomously determines whether it corresponds to the space.

If the UE determines that the PDCCH has been transmitted by the BFR-SS, the UE may determine that the response signal to the beam recovery request (BFRQ) has been successfully received, and may complete the BFR procedure. On the other hand, when the UE determines that the PDCCH has been transmitted in the non-BFR-SS, the UE may continue the BFR procedure without determining that the response signal to the beam recovery request (BFRQ) has been successfully received.

The UE may determine whether the detected PDCCH has been transmitted by the BFR-SS based on a predetermined condition (for example, AL). For example, the UE may determine that the PDCCH has been transmitted by BFR-SS when the detected PDCCH candidate AL is equal to or greater than a predetermined value in a range where a plurality of search spaces overlap.

As described above, by autonomously determining the search space type corresponding to the received PDCCH on the UE side, transmission of the BFR PDCCH can be flexibly controlled.

In Rule 1-3, the UE may transmit an acknowledgment signal (also referred to as HARQ-ACK, ACK / NACK) for the PDCCH (or the PDSCH scheduled by DCI transmitted on the PDCCH). In this case, the UE may determine a UL channel for transmitting ACK / NACK based on the DCI type.

For example, when DCI indicates PDSCH scheduling (for example, DCI is DL assignment), the UE may feed back ACK / NACK using an uplink control channel. Further, when DCI instructs scheduling of PUSCH (for example, DCI is UL grant), the UE may feed back ACK / NACK using the uplink shared channel.

The base station may reset the beam in the BFR procedure of Rule 1-3. Alternatively, the base station ends the BFR operation (eg, PRACH transmission) in the UE by transmitting a BFRQ response signal to the UE in the BFR-SS, and performs another beam control (eg, designation of another beam). You may.

(Second aspect)
In the second aspect, when a downlink control channel is detected in a range where the first search space corresponding to the first control resource set and the second search space corresponding to the second control resource set overlap, The search space in which the downlink control channel has been transmitted is determined based on the downlink control information transmitted on the downlink control channel.

In the second example, it is determined whether or not the PDCCH has been transmitted by the BFR-SS based on the signal or the channel (for example, DCI) received by the UE instead of the rule 1-3 in the first example. In the following description, points different from the first embodiment will be described, and the other portions can be performed in the same manner as the first embodiment.

<Information included in DCI>
The UE may determine whether or not the detected PDCCH has been transmitted by the BFR-SS based on information included in DCI transmitted on the detected PDCCH.

The base station may include information for notifying that the DCI is a DCI for BFR to DCI used for transmission of a response signal to BFRQ (for example, DCI for scheduling a PDSCH including the response signal). Good.

When the UE detects a PDCCH in a range where the BFR search space (search space #B) and another search space (search space #A) overlap, based on information included in DCI transmitted on the PDCCH. It is determined which search space the PDCCH corresponds to (see FIG. 6). For example, when the received DCI includes information (for example, a predetermined bit value) indicating that the DCI is DCI for BFR, the UE has received the PDCCH (PDCCH for BFR) in search space #B. Judge. Then, the UE may determine that the response signal to the beam recovery request (BFRQ) has been successfully received, and may complete the BFR procedure.

On the other hand, if the received DCI does not include information indicating that the DCI is a DCI for BFR, the UE determines that a PDCCH (PDCCH for non-BFR) has been received in search space #A. In this case, the UE may continue the BFR procedure without determining that the response signal to the beam recovery request (BFRQ) has been successfully received.

Note that the information indicating the DCI for BFR (predetermined bit value) may be included in each DCI in a predetermined number of bits (for example, 1 bit). For example, when the predetermined bit value included in DCI is 1, it may indicate that the DCI is BFR DCI, and when 0, it may indicate that it is non-BFR DCI. Alternatively, a configuration may be adopted in which the predetermined bit value (or bit field) is included only in the DCI for BFR, and the predetermined bit value is not included in the DCI for non-BFR.

The UE determines whether or not the detected PDCCH is for BFR even if the search space is set up by determining whether or not the DCI is for BFR based on the received DCI. Can be appropriately determined to control the BFR procedure. As a result, it is possible to suppress deterioration in communication throughput and communication quality.

<DCI format>
The UE may determine whether the detected PDCCH has been transmitted by the BFR-SS based on the format of the DCI transmitted on the detected PDCCH.

When the UE detects a PDCCH in a range where the BFR search space (search space #B) and another search space (search space #A) overlap, any one of the PDCCHs is determined based on the DCI format transmitted on the PDCCH. (See FIG. 6).

For example, when the DCI is in the first format, the UE determines that the detected PDCCH has been transmitted by BFR-SS or that the PDCCH (PDCCH for BFR) has been received in search space #B. Then, the UE may determine that the response signal to the beam recovery request (BFRQ) has been successfully received, and may complete the BFR procedure.

On the other hand, if the DCI is in the second format, the UE determines that the detected PDCCH has been transmitted by non-BFR-SS or that the PDCCH (non-BFR PDCCH) has been received in search space #A. In this case, the UE may continue the BFR procedure without determining that the response signal to the beam recovery request (BFRQ) has been successfully received.

The first DCI format may be, for example, at least one of DCI formats 0_0 and 1_0. The second DCI format may be, for example, at least one of DCI formats 0_1 and 1_1. Of course, the first DCI format and the second DCI format are not limited to this. At least one of the first DCI format and the second DCI format may be preset from the base station to the UE.

The UE determines whether or not the detected PDCCH is for BFR even when the search space is set up by determining whether or not the DCI is for BFR based on the format of the received DCI. The BFR procedure can be controlled by appropriately determining whether or not the BFR procedure is performed. As a result, it is possible to suppress deterioration in communication throughput and communication quality.

(Wireless communication system)
Hereinafter, the configuration of the wireless communication system according to the present embodiment will be described. In this wireless communication system, communication is performed using any of the wireless communication methods according to the above embodiments of the present disclosure or a combination thereof.

FIG. 7 is a diagram showing an example of a schematic configuration of the wireless communication system according to the present embodiment. In the wireless communication system 1, carrier aggregation (CA) and / or dual connectivity (DC) in which a plurality of component carriers (carriers or cells) are integrated can be applied.

The wireless communication system 1 includes LTE (Long Term Evolution), LTE-A (LTE-Advanced), LTE-B (LTE-Beyond), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), and 5G. (5th generation mobile communication system), NR (New Radio), FRA (Future Radio Access), New-RAT (Radio Access Technology), etc., or a system for realizing these.

The wireless communication system 1 includes a base station 11 forming a macro cell C1 having relatively wide coverage, and a base station 12 (12a to 12c) arranged in the macro cell C1 and forming a small cell C2 smaller than the macro cell C1. Have. Further, user terminals 20 are arranged in the macro cell C1 and each small cell C2. The arrangement, number, and the like of each cell and the user terminals 20 are not limited to the modes shown in the figure.

The user terminal 20 can be connected to both the base station 11 and the base station 12. It is assumed that the user terminal 20 uses the macro cell C1 and the small cell C2 simultaneously using CA or DC. Further, the user terminal 20 may apply CA or DC using a plurality of cells (CC).

Also, the wireless communication system 1 may support dual connectivity between a plurality of RATs (Radio Access Technology) (multi-RAT dual connectivity (MR-DC: Multi-RAT Dual Connectivity)). The MR-DC has dual connectivity (LTE and NR) in which an LTE (E-UTRA) base station (eNB) becomes a master node (MN) and an NR base station (gNB) becomes a secondary node (SN). EN-DC: E-UTRA-NR {Dual} Connectivity, NR base station (gNB) becomes MN, and LTE (E-UTRA) base station (eNB) becomes SN. Dual connectivity (NR and LTE) NE-DC: NR-E-UTRA {Dual} Connectivity) may be included. In addition, the wireless communication system 1 performs dual connectivity between a plurality of base stations in the same RAT (for example, dual connectivity (NN-DC: NR-NR Dual) in which both MN and SN become NR base stations (gNB). Connectivity)).

Communication between the user terminal 20 and the base station 11 can be performed using a carrier having a relatively low frequency band (for example, 2 GHz) and a narrow bandwidth (also referred to as an existing carrier or a legacy carrier). On the other hand, between the user terminal 20 and the base station 12, a carrier having a relatively high frequency band (for example, 3.5 GHz, 5 GHz, or the like) and a wide bandwidth may be used, or between the user terminal 20 and the base station 11. The same carrier as described above may be used. Note that the configuration of the frequency band used by each base station is not limited to this.

The user terminal 20 can perform communication using time division duplex (TDD: Time Division Duplex) and / or frequency division duplex (FDD: Frequency Division Duplex) in each cell. In each cell (carrier), a single numerology may be applied, or a plurality of different numerologies may be applied.

Numerology may be a communication parameter applied to transmission and / or reception of a certain signal and / or channel, for example, subcarrier interval, bandwidth, symbol length, cyclic prefix length, subframe length. , TTI length, number of symbols per TTI, radio frame configuration, specific filtering processing performed by the transceiver in the frequency domain, specific windowing processing performed by the transceiver in the time domain, and the like. For example, for a certain physical channel, if the subcarrier intervals of the constituent OFDM symbols are different and / or if the number of OFDM symbols is different, the numerology may be referred to as different.

The base station 11 and the base station 12 (or between the two base stations 12) may be connected by wire (for example, an optical fiber or an X2 interface compliant with CPRI (Common Public Radio Interface)) or wirelessly. Good.

The base station 11 and each base station 12 are respectively connected to the upper station apparatus 30, and are connected to the core network 40 via the upper station apparatus 30. Note that the higher station apparatus 30 includes, for example, an access gateway apparatus, a radio network controller (RNC), a mobility management entity (MME), and the like, but is not limited thereto. Further, each base station 12 may be connected to the higher station apparatus 30 via the base station 11.

Note that the base station 11 is a base station having relatively wide coverage, and may be called a macro base station, an aggregation node, an eNB (eNodeB), a transmission / reception point, or the like. The base station 12 is a base station having local coverage, such as a small base station, a micro base station, a pico base station, a femto base station, a HeNB (Home eNodeB), an RRH (Remote Radio Head), a transmission / reception point, and the like. May be called. Hereinafter, when the base stations 11 and 12 are not distinguished, they are collectively referred to as a base station 10.

Each user terminal 20 is a terminal corresponding to various communication systems such as LTE and LTE-A, and may include not only mobile communication terminals (mobile stations) but also fixed communication terminals (fixed stations).

In the wireless communication system 1, Orthogonal Frequency Division Multiple Access (OFDMA) is applied to the downlink as a wireless access method, and Single Carrier-Frequency Division Multiple Access (SC-FDMA: Single Carrier) is applied to the uplink. Frequency Division Multiple Access) and / or OFDMA is applied.

OFDMA is a multicarrier transmission scheme in which a frequency band is divided into a plurality of narrow frequency bands (subcarriers), and data is mapped to each subcarrier for communication. The SC-FDMA divides a system bandwidth into bands constituted by one or continuous resource blocks for each terminal, and a single carrier transmission that reduces interference between terminals by using different bands for a plurality of terminals. It is a method. The uplink and downlink radio access schemes are not limited to these combinations, and other radio access schemes may be used.

In the wireless communication system 1, as the downlink channel, a downlink shared channel (PDSCH: Physical Downlink Shared Channel), a broadcast channel (PBCH: Physical Broadcast Channel), a downlink L1 / L2 control channel, and the like shared by each user terminal 20 are used. Used. The PDSCH transmits user data, upper layer control information, SIB (System @ Information @ Block), and the like. Also, MIB (Master \ Information \ Block) is transmitted by PBCH.

Downlink L1 / L2 control channels include PDCCH (Physical Downlink Control Channel), EPDCCH (Enhanced Physical DownlinkＦControl Channel), PCFICH (Physical Control Format Indicator Channel), PHICH (Physical Hybrid-ARQ Indicator Channel) and the like. Downlink control information (DCI: Downlink Control Information) including scheduling information of PDSCH and / or PUSCH is transmitted by PDCCH.

スケジューリング The scheduling information may be notified by DCI. For example, a DCI that schedules DL data reception may be called a DL assignment, and a DCI that schedules UL data transmission may be called an UL grant.

PCFICH transmits the number of OFDM symbols used for PDCCH. The PHICH transmits HARQ (Hybrid Automatic Repeat Repeat request) acknowledgment information (for example, retransmission control information, HARQ-ACK, ACK / NACK, etc.) for the PUSCH. The EPDCCH is frequency-division multiplexed with a PDSCH (Downlink Shared Data Channel) and used for transmission of DCI and the like like the PDCCH.

In the wireless communication system 1, as an uplink channel, an uplink shared channel (PUSCH: Physical Uplink Shared Channel), an uplink control channel (PUCCH: Physical Uplink Control Channel), and a random access channel (PRACH: Physical Random Access Channel) or the like is used. By PUSCH, user data, higher layer control information, etc. are transmitted. In addition, downlink radio quality information (CQI: Channel Quality Indicator), delivery confirmation information, scheduling request (SR: Scheduling Request), and the like are transmitted by PUCCH. The PRACH transmits a random access preamble for establishing a connection with a cell.

In the wireless communication system 1, as a downlink reference signal, a cell-specific reference signal (CRS: Cell-specific Reference Signal), a channel state information reference signal (CSI-RS: Channel State Information-Reference Signal), and a demodulation reference signal (DMRS: DeModulation Reference Signal, a position determination reference signal (PRS: Positioning Reference Signal), and the like are transmitted. In the wireless communication system 1, a reference signal for measurement (SRS: Sounding Reference Signal), a reference signal for demodulation (DMRS), and the like are transmitted as uplink reference signals. The DMRS may be called a user terminal specific reference signal (UE-specific Reference Signal). Further, the transmitted reference signal is not limited to these.

<Base station>
FIG. 8 is a diagram showing an example of the overall configuration of the base station according to the present embodiment. The base station 10 includes a plurality of transmitting / receiving antennas 101, an amplifier unit 102, a transmitting / receiving unit 103, a baseband signal processing unit 104, a call processing unit 105, and a transmission path interface 106. Note that the transmitting / receiving antenna 101, the amplifier unit 102, and the transmitting / receiving unit 103 may be configured to include at least one each.

ユーザ User data transmitted from the base station 10 to the user terminal 20 via the downlink is input from the higher station apparatus 30 to the baseband signal processing unit 104 via the transmission path interface 106.

In the baseband signal processing unit 104, regarding user data, processing of a PDCP (Packet Data Convergence Protocol) layer, division / combination of user data, transmission processing of an RLC layer such as RLC (Radio Link Control) retransmission control, and MAC (Medium Access) Control) Transmission / reception control (for example, HARQ transmission processing), scheduling, transmission format selection, channel coding, inverse fast Fourier transform (IFFT) processing, precoding processing, etc., and transmission / reception processing are performed. 103. The downlink control signal is also subjected to transmission processing such as channel coding and inverse fast Fourier transform, and is transferred to the transmission / reception unit 103.

(4) The transmission / reception unit 103 converts the baseband signal precoded and output from the baseband signal processing unit 104 for each antenna into a radio frequency band, and transmits the radio frequency band. The radio frequency signal frequency-converted by the transmitting / receiving section 103 is amplified by the amplifier section 102 and transmitted from the transmitting / receiving antenna 101. The transmission / reception unit 103 can be configured by a transmitter / receiver, a transmission / reception circuit, or a transmission / reception device described based on common recognition in the technical field according to the present disclosure. Note that the transmission / reception unit 103 may be configured as an integrated transmission / reception unit, or may be configured from a transmission unit and a reception unit.

On the other hand, as for an uplink signal, a radio frequency signal received by the transmission / reception antenna 101 is amplified by the amplifier unit 102. The transmitting / receiving section 103 receives the upstream signal amplified by the amplifier section 102. Transmitting / receiving section 103 frequency-converts the received signal into a baseband signal and outputs the baseband signal to baseband signal processing section 104.

The baseband signal processing unit 104 performs fast Fourier transform (FFT: Fast Fourier Transform), inverse discrete Fourier transform (IDFT), and error correction on user data included in the input uplink signal. Decoding, reception processing of MAC retransmission control, reception processing of the RLC layer and PDCP layer are performed, and the data is transferred to the upper station apparatus 30 via the transmission path interface 106. The call processing unit 105 performs call processing (setting, release, etc.) of a communication channel, state management of the base station 10, management of radio resources, and the like.

(4) The transmission path interface 106 transmits and receives signals to and from the higher-level station device 30 via a predetermined interface. The transmission line interface 106 transmits and receives signals (backhaul signaling) to and from another base station 10 via an interface between base stations (for example, an optical fiber compliant with CPRI (Common Public Radio Interface), an X2 interface). Is also good.

FIG. 9 is a diagram showing an example of a functional configuration of the base station according to the present embodiment. In this example, functional blocks of characteristic portions in the present embodiment are mainly shown, and it may be assumed that base station 10 also has other functional blocks necessary for wireless communication.

The baseband signal processing unit 104 includes at least a control unit (scheduler) 301, a transmission signal generation unit 302, a mapping unit 303, a reception signal processing unit 304, and a measurement unit 305. Note that these configurations only need to be included in base station 10, and some or all of the configurations need not be included in baseband signal processing section 104.

The control unit (scheduler) 301 controls the entire base station 10. The control unit 301 can be configured from a controller, a control circuit, or a control device described based on common recognition in the technical field according to the present disclosure.

The control unit 301 controls, for example, signal generation in the transmission signal generation unit 302, signal assignment in the mapping unit 303, and the like. Further, the control unit 301 controls a signal reception process in the reception signal processing unit 304, a signal measurement in the measurement unit 305, and the like.

The control unit 301 performs scheduling (for example, resource transmission) of system information, a downlink data signal (for example, a signal transmitted on the PDSCH), and a downlink control signal (for example, a signal transmitted on the PDCCH and / or the EPDCCH; Quota). Further, control section 301 controls generation of a downlink control signal, a downlink data signal, and the like based on a result of determining whether or not retransmission control is required for an uplink data signal.

The control unit 301 controls scheduling of a synchronization signal (for example, PSS (Primary Synchronization Signal) / SSS (Secondary Synchronization Signal)) and a downlink reference signal (for example, CRS, CSI-RS, and DMRS).

The control unit 301 includes an uplink data signal (for example, a signal transmitted on the PUSCH), an uplink control signal (for example, a signal transmitted on the PUCCH and / or PUSCH, acknowledgment information, etc.), a random access preamble (for example, (Transmission signal), uplink reference signal, and the like.

Transmission signal generation section 302 generates a downlink signal (downlink control signal, downlink data signal, downlink reference signal, etc.) based on an instruction from control section 301, and outputs the generated signal to mapping section 303. The transmission signal generation unit 302 can be configured from a signal generator, a signal generation circuit, or a signal generation device described based on common recognition in the technical field according to the present disclosure.

The transmission signal generation unit 302 generates a DL assignment for notifying downlink data allocation information and / or a UL grant for notifying uplink data allocation information, based on an instruction from the control unit 301, for example. The DL assignment and the UL grant are both DCI and follow the DCI format. In addition, the downlink data signal is subjected to an encoding process and a modulation process according to an encoding rate, a modulation scheme, and the like determined based on channel state information (CSI: Channel \ State \ Information) from each user terminal 20 or the like.

Mapping section 303 maps the downlink signal generated by transmission signal generation section 302 to a predetermined radio resource based on an instruction from control section 301, and outputs the result to transmission / reception section 103. The mapping unit 303 can be configured by a mapper, a mapping circuit, or a mapping device described based on common recognition in the technical field according to the present disclosure.

(4) The reception signal processing unit 304 performs reception processing (for example, demapping, demodulation, and decoding) on the reception signal input from the transmission / reception unit 103. Here, the received signal is, for example, an uplink signal (uplink control signal, uplink data signal, uplink reference signal, etc.) transmitted from the user terminal 20. The reception signal processing unit 304 can be configured from a signal processor, a signal processing circuit, or a signal processing device described based on common recognition in the technical field according to the present disclosure.

(4) The reception signal processing unit 304 outputs the information decoded by the reception processing to the control unit 301. For example, when a PUCCH including HARQ-ACK is received, HARQ-ACK is output to control section 301. Further, the reception signal processing unit 304 outputs the reception signal and / or the signal after the reception processing to the measurement unit 305.

The measurement unit 305 performs measurement on the received signal. The measurement unit 305 can be configured from a measurement device, a measurement circuit, or a measurement device described based on common recognition in the technical field according to the present disclosure.

For example, the measurement unit 305 may perform RRM (Radio Resource Management) measurement, CSI (Channel State Information) measurement, or the like based on the received signal. Measuring section 305 receives power (for example, RSRP (Reference Signal Received Power)), reception quality (for example, RSRQ (Reference Signal Received Quality), SINR (Signal to Interference plus Noise Ratio), SNR (Signal to Noise Ratio)). , Signal strength (for example, RSSI (Received Signal Strength Indicator)), channel information (for example, CSI), and the like may be measured. The measurement result may be output to the control unit 301.

The transmission / reception unit 103 transmits a downlink control channel (or DCI) in a beam failure recovery (BFR) procedure. Further, the transmitting / receiving section 103 transmits a PDSCH (for example, a BFRQ response) scheduled on the downlink control channel (or DCI). In addition, the transmitting / receiving section 103 may transmit information on the control resource set and the search space monitored by the UE in response to the BFRQ response by higher layer signaling or the like.

The control unit 301 controls the setting of the control resource set and the search space monitored by the UE in response to the BFRQ response.

<User terminal>
FIG. 10 is a diagram showing an example of the overall configuration of the user terminal according to the present embodiment. The user terminal 20 includes a plurality of transmitting / receiving antennas 201, an amplifier unit 202, a transmitting / receiving unit 203, a baseband signal processing unit 204, and an application unit 205. The transmitting / receiving antenna 201, the amplifier unit 202, and the transmitting / receiving unit 203 may be configured to include at least one each.

(4) The radio frequency signal received by the transmitting / receiving antenna 201 is amplified by the amplifier unit 202. The transmission / reception unit 203 receives the downlink signal amplified by the amplifier unit 202. The transmitting / receiving section 203 converts the frequency of the received signal into a baseband signal and outputs the baseband signal to the baseband signal processing section 204. The transmission / reception unit 203 can be configured from a transmitter / receiver, a transmission / reception circuit, or a transmission / reception device described based on common recognition in the technical field according to the present disclosure. Note that the transmission / reception unit 203 may be configured as an integrated transmission / reception unit, or may be configured from a transmission unit and a reception unit.

The baseband signal processing unit 204 performs FFT processing, error correction decoding, reception processing for retransmission control, and the like on the input baseband signal. The downlink user data is transferred to the application unit 205. The application unit 205 performs processing related to layers higher than the physical layer and the MAC layer. Also, of the downlink data, broadcast information may be transferred to the application unit 205.

On the other hand, uplink user data is input from the application unit 205 to the baseband signal processing unit 204. The baseband signal processor 204 performs retransmission control transmission processing (eg, HARQ transmission processing), channel coding, precoding, discrete Fourier transform (DFT) processing, IFFT processing, and the like, and performs transmission / reception processing. Transferred to 203.

(4) The transmission / reception unit 203 converts the baseband signal output from the baseband signal processing unit 204 into a radio frequency band and transmits the radio frequency band. The radio frequency signal frequency-converted by the transmitting / receiving section 203 is amplified by the amplifier section 202 and transmitted from the transmitting / receiving antenna 201.

FIG. 11 is a diagram illustrating an example of a functional configuration of the user terminal according to the present embodiment. Note that, in this example, functional blocks of characteristic portions in the present embodiment are mainly shown, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication.

The baseband signal processing unit 204 of the user terminal 20 includes at least a control unit 401, a transmission signal generation unit 402, a mapping unit 403, a reception signal processing unit 404, and a measurement unit 405. Note that these configurations need only be included in the user terminal 20, and some or all of the configurations need not be included in the baseband signal processing unit 204.

The control unit 401 controls the entire user terminal 20. The control unit 401 can be configured from a controller, a control circuit, or a control device described based on common recognition in the technical field according to the present disclosure.

The control unit 401 controls, for example, signal generation in the transmission signal generation unit 402, signal assignment in the mapping unit 403, and the like. Further, the control unit 401 controls a signal reception process in the reception signal processing unit 404, a signal measurement in the measurement unit 405, and the like.

The control unit 401 acquires the downlink control signal and the downlink data signal transmitted from the base station 10 from the reception signal processing unit 404. The control unit 401 controls generation of an uplink control signal and / or an uplink data signal based on a result of determining whether or not retransmission control is required for a downlink control signal and / or a downlink data signal.

The control unit 401 transmits a predetermined identifier (for example, C-RNTI, CS-RNTI, MCS-C-RNTI, SI-RNTI, P-RNTI, RA-RNTI, TC-RNTI, INT-RNTI, SFI-RNTI, TPC -PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, SP-CSI-RNTI).

When the control unit 401 acquires various information notified from the base station 10 from the reception signal processing unit 404, the control unit 401 may update parameters used for control based on the information.

Transmission signal generation section 402 generates an uplink signal (uplink control signal, uplink data signal, uplink reference signal, etc.) based on an instruction from control section 401 and outputs the generated signal to mapping section 403. The transmission signal generation unit 402 can be configured from a signal generator, a signal generation circuit, or a signal generation device described based on common recognition in the technical field according to the present disclosure.

(4) The transmission signal generation unit 402 generates an uplink control signal related to acknowledgment information, channel state information (CSI), and the like based on an instruction from the control unit 401, for example. Further, transmission signal generating section 402 generates an uplink data signal based on an instruction from control section 401. For example, the transmission signal generation unit 402 is instructed by the control unit 401 to generate an uplink data signal when the downlink control signal notified from the base station 10 includes a UL grant.

Mapping section 403 maps the uplink signal generated by transmission signal generation section 402 to a radio resource based on an instruction from control section 401, and outputs the result to transmission / reception section 203. The mapping unit 403 can be configured from a mapper, a mapping circuit, or a mapping device described based on common recognition in the technical field according to the present disclosure.

(4) The reception signal processing unit 404 performs reception processing (for example, demapping, demodulation, and decoding) on the reception signal input from the transmission / reception unit 203. Here, the received signal is, for example, a downlink signal (a downlink control signal, a downlink data signal, a downlink reference signal, etc.) transmitted from the base station 10. The reception signal processing unit 404 can be configured from a signal processor, a signal processing circuit, or a signal processing device described based on common recognition in the technical field according to the present disclosure. In addition, the reception signal processing unit 404 can configure a reception unit according to the present disclosure.

(4) The reception signal processing unit 404 outputs the information decoded by the reception processing to the control unit 401. The reception signal processing unit 404 outputs, for example, broadcast information, system information, RRC signaling, DCI, and the like to the control unit 401. Further, the reception signal processing unit 404 outputs the reception signal and / or the signal after the reception processing to the measurement unit 405.

The measuring unit 405 measures the received signal. The measurement unit 405 can be configured from a measurement device, a measurement circuit, or a measurement device described based on common recognition in the technical field according to the present disclosure.

For example, the measurement unit 405 may perform RRM measurement, CSI measurement, and the like based on the received signal. The measurement unit 405 may measure reception power (for example, RSRP), reception quality (for example, RSRQ, SINR, SNR), signal strength (for example, RSSI), and channel information (for example, CSI). The measurement result may be output to the control unit 401.

Note that the transmission / reception unit 203 monitors the downlink control channel (or DCI) in the beam failure recovery (BFR) procedure and receives the DCI. Further, the transmission / reception unit 203 receives a PDSCH (for example, a BFRQ response) scheduled on the downlink control channel (or DCI). In addition, the transmission / reception unit 203 may receive information on a control resource set and a search space monitored for a BFRQ response by higher layer signaling or the like.

The control unit 401 controls the downlink control channel in a range where the first search space corresponding to the first control resource set and the second search space corresponding to the second control resource set set for BFR overlap. Is detected, the search space in which the downlink control channel is transmitted is determined based on a predetermined rule or downlink control information transmitted on the downlink control channel.

For example, when detecting the downlink control channel in the overlapping range of the first search space and the second search space, the control unit 401 may determine that the downlink control channel has been transmitted in the second search space. Alternatively, when detecting the downlink control channel in the overlapping range of the first search space and the second search space, control section 401 may determine that the downlink control channel has been transmitted in the first search space.

The control unit 401 may perform control so that the response signal to the beam recovery request is received within a range where the first search space and the second search space do not overlap.

{Also, control section 401 may determine the search space in which the PDCCH has been transmitted, based on information included in the downlink control information transmitted on the downlink control channel. Alternatively, control section 401 may determine the search space in which the PDCCH has been transmitted, based on the format of the downlink control information transmitted on the downlink control channel.

<Hardware configuration>
Note that the block diagram used in the description of the above-described embodiment shows blocks in functional units. These functional blocks (components) are realized by an arbitrary combination of at least one of hardware and software. In addition, a method of implementing each functional block is not particularly limited. That is, each functional block may be realized using one device physically or logically coupled, or directly or indirectly (for example, two or more devices physically or logically separated). , Wired, wireless, etc.), and may be implemented using these multiple devices. The functional block may be realized by combining one device or the plurality of devices with software.

Here, the functions include judgment, determination, judgment, calculation, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, and deemed. , Broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc. Not limited. For example, a functional block (configuration unit) that causes transmission to function may be referred to as a transmitting unit (transmitting unit), a transmitter (transmitter), or the like. In any case, as described above, the realization method is not particularly limited.

For example, a base station, a user terminal, and the like according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method according to the present disclosure. FIG. 12 is a diagram illustrating an example of a hardware configuration of a base station and a user terminal according to one embodiment. The above-described base station 10 and user terminal 20 may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like. .

In the present disclosure, the terms such as “apparatus”, “circuit”, “device”, “section”, and “unit” can be read interchangeably. The hardware configuration of the base station 10 and the user terminal 20 may be configured to include one or more of the devices illustrated in the drawing, or may be configured to exclude some of the devices.

For example, although only one processor 1001 is illustrated, there may be multiple processors. Further, the processing may be executed by one processor, or the processing may be executed by two or more processors simultaneously, sequentially, or by using another method. Note that the processor 1001 may be implemented by one or more chips.

The functions of the base station 10 and the user terminal 20 are performed, for example, by reading predetermined software (program) on hardware such as the processor 1001 and the memory 1002 so that the processor 1001 performs an arithmetic operation and communicates via the communication device 1004. And controlling at least one of reading and writing of data in the memory 1002 and the storage 1003.

The processor 1001 controls the entire computer by operating an operating system, for example. The processor 1001 may be configured by a central processing unit (CPU: Central Processing Unit) including an interface with a peripheral device, a control device, an arithmetic device, a register, and the like. For example, the above-described baseband signal processing unit 104 (204), call processing unit 105, and the like may be realized by the processor 1001.

The processor 1001 reads out a program (program code), a software module, data, and the like from at least one of the storage 1003 and the communication device 1004 to the memory 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operation described in the above embodiment is used. For example, the control unit 401 of the user terminal 20 may be implemented by a control program stored in the memory 1002 and operated by the processor 1001, and other functional blocks may be implemented similarly.

The memory 1002 is a computer-readable recording medium, for example, at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically EPROM), RAM (Random Access Memory), and other appropriate storage media. It may be constituted by one. The memory 1002 may be called a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store a program (program code), a software module, and the like that can be executed to execute the wireless communication method according to an embodiment of the present disclosure.

The storage 1003 is a computer-readable recording medium such as a flexible disk, a floppy (registered trademark) disk, a magneto-optical disk (for example, a compact disk (CD-ROM (Compact Disc) ROM, etc.), a digital versatile disc, At least one of a Blu-ray (registered trademark) disk, a removable disk, a hard disk drive, a smart card, a flash memory device (eg, a card, a stick, a key drive), a magnetic stripe, a database, a server, and other suitable storage media. May be configured. The storage 1003 may be called an auxiliary storage device.

The communication device 1004 is hardware (transmission / reception device) for performing communication between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like. The communication device 1004 includes a high-frequency switch, a duplexer, a filter, a frequency synthesizer, and the like, for example, in order to realize at least one of frequency division duplex (FDD: Frequency Division Duplex) and time division duplex (TDD: Time Division Duplex). May be configured. For example, the transmission / reception antenna 101 (201), the amplifier unit 102 (202), the transmission / reception unit 103 (203), the transmission path interface 106, and the like may be realized by the communication device 1004. The transmission / reception unit 103 (203) may be physically or logically separated from the transmission unit 103a (203a) and the reception unit 103b (203b).

The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, and the like) that receives an external input. The output device 1006 is an output device that performs output to the outside (for example, a display, a speaker, an LED (Light Emitting Diode) lamp, and the like). Note that the input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

The devices such as the processor 1001 and the memory 1002 are connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using a different bus for each device.

In addition, the base station 10 and the user terminal 20 include hardware such as a microprocessor, a digital signal processor (DSP: Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), and an FPGA (Field Programmable Gate Array). It may be configured to include hardware, and some or all of the functional blocks may be realized using the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

(Modification)
Note that terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meaning. For example, channels, symbols and signals (signals or signaling) may be read interchangeably. Also, the signal may be a message. The reference signal may be abbreviated as RS (Reference Signal), and may be referred to as a pilot, a pilot signal, or the like according to an applied standard. A component carrier (CC: Component Carrier) may be called a cell, a frequency carrier, a carrier frequency, or the like.

A radio frame may be configured by one or more periods (frames) in the time domain. The one or more respective periods (frames) forming the radio frame may be referred to as a subframe. Further, a subframe may be configured by one or more slots in the time domain. The subframe may be of a fixed length of time (eg, 1 ms) that does not depend on numerology.

Here, the new melology may be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. Numerology includes, for example, subcarrier interval (SCS: SubCarrier @ Spacing), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI: Transmission @ Time @ Interval), number of symbols per TTI, radio frame configuration, transmission and reception. At least one of a specific filtering process performed by the transceiver in the frequency domain and a specific windowing process performed by the transceiver in the time domain may be indicated.

The slot may be configured by one or a plurality of symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbol, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbol, etc.) in the time domain. Further, the slot may be a time unit based on numerology.

The slot may include a plurality of mini slots. Each minislot may be constituted by one or more symbols in the time domain. Also, the mini-slot may be called a sub-slot. A minislot may be made up of a smaller number of symbols than slots. A PDSCH (or PUSCH) transmitted in time units larger than minislots may be referred to as PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be referred to as a PDSCH (PUSCH) mapping type B.

Radio frames, subframes, slots, minislots, and symbols all represent time units when transmitting signals. The radio frame, the subframe, the slot, the minislot, and the symbol may have different names corresponding to each. Note that time units such as frames, subframes, slots, minislots, and symbols in the present disclosure may be interchanged with each other.

For example, one subframe may be called a TTI, a plurality of consecutive subframes may be called a TTI, and one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in the existing LTE, a period shorter than 1 ms (for example, 1 to 13 symbols), or a period longer than 1 ms. It may be. Note that the unit representing the TTI may be called a slot, a minislot, or the like instead of a subframe.

Here, the TTI refers to, for example, a minimum time unit of scheduling in wireless communication. For example, in the LTE system, the base station performs scheduling for allocating radio resources (frequency bandwidth, transmission power, and the like that can be used in each user terminal) to each user terminal in TTI units. Note that the definition of TTI is not limited to this.

The TTI may be a transmission time unit such as a channel-encoded data packet (transport block), a code block, or a code word, or may be a processing unit such as scheduling and link adaptation. Note that when a TTI is given, a time section (for example, the number of symbols) in which a transport block, a code block, a codeword, and the like are actually mapped may be shorter than the TTI.

If one slot or one minislot is called a TTI, one or more TTIs (ie, one or more slots or one or more minislots) may be the minimum time unit for scheduling. Further, the number of slots (mini-slot number) constituting the minimum time unit of the scheduling may be controlled.

A TTI having a time length of 1 ms may be referred to as a normal TTI (TTI in [email protected]), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, and the like. A TTI shorter than the normal TTI may be called a shortened TTI, a short TTI, a partial TTI (partial or fractional TTI), a shortened subframe, a short subframe, a minislot, a subslot, a slot, and the like.

Note that a long TTI (for example, a normal TTI, a subframe, etc.) may be read as a TTI having a time length exceeding 1 ms, and a short TTI (for example, a shortened TTI, etc.) may be replaced with a TTI shorter than the long TTI and 1 ms. The TTI having the above-described TTI length may be replaced with the TTI.

A resource block (RB: Resource Block) is a resource allocation unit in the time domain and the frequency domain, and may include one or a plurality of continuous subcarriers (subcarriers) in the frequency domain. The number of subcarriers included in the RB may be the same irrespective of the numerology, and may be, for example, 12. The number of subcarriers included in the RB may be determined based on numerology.

Ｒ Also, the RB may include one or more symbols in the time domain, and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, and the like may each be configured by one or a plurality of resource blocks.

Note that one or more RBs include a physical resource block (PRB: Physical @ RB), a subcarrier group (SCG: Sub-Carrier @ Group), a resource element group (REG: Resource @ Element @ Group), a PRB pair, an RB pair, and the like. May be called.

{Also, a resource block may be composed of one or more resource elements (RE: Resource @ Element). For example, one RE may be a radio resource area of one subcarrier and one symbol.

A bandwidth part (BWP: Bandwidth @ Part) (which may be referred to as a partial bandwidth or the like) may also represent a subset of consecutive common RBs (common @ resource @ blocks) for a certain numerology in a certain carrier. Good. Here, the common RB may be specified by an index of the RB based on the common reference point of the carrier. A PRB may be defined by a BWP and numbered within the BWP.

$ BWP may include a BWP for UL (UL @ BWP) and a BWP for DL (DL @ BWP). For a UE, one or more BWPs may be configured in one carrier.

少なくとも At least one of the configured BWPs may be active, and the UE does not have to assume to transmit and receive a given signal / channel outside the active BWP. Note that “cell”, “carrier”, and the like in the present disclosure may be replaced with “BWP”.

The structures of the above-described radio frame, subframe, slot, minislot, symbol, and the like are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, included in an RB The configuration of the number of subcarriers, the number of symbols in the TTI, the symbol length, the cyclic prefix (CP: Cyclic @ Prefix) length, and the like can be variously changed.

Further, the information, parameters, and the like described in the present disclosure may be expressed using an absolute value, may be expressed using a relative value from a predetermined value, or may be expressed using another corresponding information. May be represented. For example, a radio resource may be indicated by a predetermined index.

名称 Names used for parameters and the like in the present disclosure are not limited in any respect. Further, the formulas and the like using these parameters may be different from those explicitly disclosed in the present disclosure. The various channels (PUCCH (Physical Uplink Control Channel), PDCCH (Physical Downlink Control Channel), etc.) and information elements can be identified by any suitable name, so the various names assigned to these various channels and information elements Is not a limiting name in any way.

The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc., that can be referred to throughout the above description are not limited to voltages, currents, electromagnetic waves, magnetic or magnetic particles, optical or photons, or any of these. May be represented by a combination of

情報 In addition, information, signals, and the like can be output from the upper layer to at least one of the lower layer and the lower layer to the upper layer. Information, signals, etc. may be input / output via a plurality of network nodes.

(4) Information and signals input and output may be stored in a specific place (for example, a memory) or may be managed using a management table. Information and signals that are input and output can be overwritten, updated, or added. The output information, signal, and the like may be deleted. The input information, signal, and the like may be transmitted to another device.

通知 Notification of information is not limited to the aspect / embodiment described in the present disclosure, and may be performed using another method. For example, the information is notified by physical layer signaling (for example, downlink control information (DCI: Downlink Control Information), uplink control information (UCI: Uplink Control Information)), higher layer signaling (for example, RRC (Radio Resource Control) signaling, It may be implemented by broadcast information (master information block (MIB: Master Information Block), system information block (SIB: System Information Block), etc.), MAC (Medium Access Control) signaling), other signals, or a combination thereof.

Note that the physical layer signaling may be called L1 / L2 (Layer 1 / Layer 2) control information (L1 / L2 control signal), L1 control information (L1 control signal), or the like. The RRC signaling may be referred to as an RRC message, and may be, for example, an RRC connection setup (RRC Connection Setup) message, an RRC connection reconfiguration (RRC Connection Reconfiguration) message, or the like. Also, the MAC signaling may be notified using, for example, a MAC control element (MAC @ CE (Control @ Element)).

Further, the notification of the predetermined information (for example, the notification of “X”) is not limited to an explicit notification, and is implicit (for example, by not performing the notification of the predetermined information or by another information). May be performed).

The determination may be made by a value represented by 1 bit (0 or 1), or may be made by a boolean value represented by true or false. , May be performed by comparing numerical values (for example, comparison with a predetermined value).

Software, regardless of whether it is called software, firmware, middleware, microcode, a hardware description language, or any other name, instructions, instruction sets, codes, code segments, program codes, programs, subprograms, software modules , Applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, and the like.

ソフトウェア Also, software, instructions, information, and the like may be transmitted and received via a transmission medium. For example, if the software uses at least one of wired technology (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and wireless technology (infrared, microwave, etc.), the website, When transmitted from a server or other remote source, at least one of these wired and / or wireless technologies is included within the definition of a transmission medium.

用語 The terms “system” and “network” as used in this disclosure may be used interchangeably.

In the present disclosure, “precoding”, “precoder”, “weight (precoding weight)”, “quasi-co-location (QCL)”, “TCI state (Transmission Configuration Indication state)”, “spatial relation” (Spatial relation), "spatial domain filter", "transmission power", "phase rotation", "antenna port", "antenna port group", "layer", "number of layers", " Terms such as "rank", "resource", "resource set", "resource group", "beam", "beam width", "beam angle", "antenna", "antenna element", "panel" are interchangeable Can be used for

In the present disclosure, “base station (BS: Base @ Station)”, “wireless base station”, “fixed station (fixed @ station)”, “NodeB”, “eNodeB (eNB)”, “gNodeB (gNB)”, “gNodeB (gNB)” "Access point (access @ point)", "transmission point (TP: Transmission @ Point)", "reception point (RP: Reception @ Point)", "transmission / reception point (TRP: Transmission / Reception @ Point)", "panel", "cell" , "Sector", "cell group", "carrier", "component carrier" and the like may be used interchangeably. A base station may also be referred to as a macro cell, a small cell, a femto cell, a pico cell, or the like.

A base station can accommodate one or more (eg, three) cells. If the base station accommodates multiple cells, the entire coverage area of the base station can be partitioned into multiple smaller areas, each smaller area being a base station subsystem (eg, a small indoor base station (RRH: Communication services can also be provided by Remote Radio Head)). The term "cell" or "sector" refers to part or all of the coverage area of at least one of a base station and a base station subsystem that provides communication services in this coverage.

In the present disclosure, terms such as “mobile station (MS)”, “user terminal”, “user equipment” (UE), and “terminal” may be used interchangeably. .

A mobile station is a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal. , Handset, user agent, mobile client, client or some other suitable terminology.

少なくとも At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, or the like. Note that at least one of the base station and the mobile station may be a device mounted on the mobile unit, the mobile unit itself, or the like. The moving object may be a vehicle (for example, a car, an airplane, or the like), may be an unmanned moving object (for example, a drone, an autonomous vehicle), or may be a robot (maned or unmanned). ). Note that at least one of the base station and the mobile station includes a device that does not necessarily move during a communication operation. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

基地 Also, the base station in the present disclosure may be replaced with a user terminal. For example, communication between a base station and a user terminal is replaced with communication between a plurality of user terminals (for example, may be called D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). Regarding the configuration, each aspect / embodiment of the present disclosure may be applied. In this case, the configuration may be such that the user terminal 20 has the function of the base station 10 described above. Further, words such as “up” and “down” may be read as words corresponding to communication between terminals (for example, “side”). For example, an uplink channel, a downlink channel, and the like may be replaced with a side channel.

Similarly, the user terminal in the present disclosure may be replaced with a base station. In this case, a configuration in which the base station 10 has the function of the user terminal 20 described above may be adopted.

In the present disclosure, the operation performed by the base station may be performed by an upper node (upper node) in some cases. In a network including one or more network nodes having a base station (network @ nodes), various operations performed for communication with a terminal include a base station, one or more network nodes other than the base station (eg, Obviously, it can be performed by MME (Mobility Management Entity), S-GW (Serving-Gateway) or the like, but not limited thereto, or a combination thereof.

各 Each aspect / embodiment described in the present disclosure may be used alone, may be used in combination, or may be used by switching with execution. In addition, the order of the processing procedure, sequence, flowchart, and the like of each aspect / embodiment described in the present disclosure may be changed as long as there is no contradiction. For example, for the methods described in this disclosure, elements of various steps are presented in an exemplary order, and are not limited to the specific order presented.

Each aspect / embodiment described in the present disclosure is applicable to LTE (Long Term Evolution), LTE-A (LTE-Advanced), LTE-B (LTE-Beyond), SUPER 3G, IMT-Advanced, 4G (4th generation mobile). communication system), 5G (5th generation mobile communication system), FRA (FutureＡＴRadioRAccess), New-RAT (Radio Access Technology), NR (New Radio), NX (New radio access), FX (Future generation radio access), GSM (registered trademark) (Global System for Mobile communications), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802 .20, UWB (Ultra-WideBand), Bluetooth (registered trademark) ), A system using other appropriate wireless communication methods, a next-generation system extended based on these, and the like. Further, a plurality of systems may be combined (for example, a combination of LTE or LTE-A and 5G) and applied.

記載 The term “based on” as used in the present disclosure does not mean “based on” unless otherwise indicated. In other words, the phrase "based on" means both "based only on" and "based at least on."

いかなる Any reference to elements using designations such as "first," "second," etc., as used in this disclosure, does not generally limit the quantity or order of those elements. These designations may be used in the present disclosure as a convenient way to distinguish between two or more elements. Thus, reference to a first and second element does not mean that only two elements can be employed or that the first element must precede the second element in any way.

用語 The term "determining" as used in this disclosure may encompass a wide variety of actions. For example, “judgment (decision)” means judging, calculating, computing, processing, deriving, investigating, searching (upping, searching, inquiry) ( For example, a search in a table, database, or another data structure), ascertaining, etc., may be regarded as "deciding".

Also, “determining” includes receiving (eg, receiving information), transmitting (eg, transmitting information), input (input), output (output), and access ( accessing) (e.g., accessing data in a memory) or the like.

Also, “judgment (decision)” is regarded as “judgment (decision)” of resolving, selecting, selecting, establishing, comparing, etc. Is also good. That is, “judgment (decision)” may be regarded as “judgment (decision)” of any operation.

判断 Also, “judgment (decision)” may be read as “assuming”, “expecting”, “considering”, or the like.

The “maximum transmission power” described in the present disclosure may mean the maximum value of the transmission power, may mean the nominal maximum transmission power (the nominal UE maximum transmit power), or may refer to the rated maximum transmission power (the rated UE maximum transmit power).

As used in this disclosure, the terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements. And may include the presence of one or more intermediate elements between two elements "connected" or "coupled" to each other. The coupling or connection between the elements may be physical, logical, or a combination thereof. For example, “connection” may be read as “access”.

In this disclosure, where two elements are connected, using one or more wires, cables, printed electrical connections, etc., and as some non-limiting and non-exhaustive examples, the radio frequency domain, microwave It can be considered to be "connected" or "coupled" to each other using electromagnetic energy having a wavelength in the region, light (both visible and invisible) regions, and the like.

において In the present disclosure, the term “A and B are different” may mean that “A and B are different from each other”. The term may mean that “A and B are different from C”. Terms such as "separate", "coupled" and the like may be interpreted similarly to "different".

Where the terms “include”, “including” and variations thereof are used in the present disclosure, these terms are as inclusive as the term “comprising” Is intended. Further, the term "or" as used in the present disclosure is not intended to be an exclusive or.

In the present disclosure, where articles are added by translation, for example, a, an, and the in English, the present disclosure may include that the nouns following these articles are plural.

Although the invention according to the present disclosure has been described in detail above, it is obvious to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented as modifications and changes without departing from the spirit and scope of the invention determined based on the description of the claims. Therefore, the description of the present disclosure is intended for illustrative purposes and does not bring any restrictive meaning to the invention according to the present disclosure.

Claims

A receiving unit that monitors a downlink control channel in a beam failure recovery (BFR) procedure;
When a downlink control channel is detected in a range where the first search space corresponding to the first control resource set and the second search space corresponding to the second control resource set set for BFR overlap, A user terminal, comprising: a control unit that determines a search space in which the downlink control channel has been transmitted, based on a predetermined rule or downlink control information transmitted on the downlink control channel.
The control unit, when detecting the downlink control channel in the overlapping range of the first search space and the second search space, determines that the downlink control channel has been transmitted in the second search space. The user terminal according to claim 1, wherein
The control unit, when detecting the downlink control channel in an overlapping range of the first search space and the second search space, determines that the downlink control channel has been transmitted in the first search space. The user terminal according to claim 1, wherein
4. The user terminal according to claim 3, wherein the control unit controls to receive a response signal to the beam recovery request so that the first search space and the second search space do not overlap each other. 5.
The control unit determines a search space in which the PDCCH is transmitted, based on information included in the downlink control information transmitted on the downlink control channel or a format of the downlink control information. Item 2. The user terminal according to Item 1.
Monitoring a downlink control channel in a beam failure recovery (BFR) procedure;
When a downlink control channel is detected in a range where the first search space corresponding to the first control resource set and the second search space corresponding to the second control resource set set for BFR overlap, Determining a search space in which the downlink control channel has been transmitted, based on a predetermined rule or downlink control information transmitted on the downlink control channel.