Terminal, wireless communication method, base station, and system

Abstract

A terminal according to one embodiment of this disclosure is characterized by including: a reception unit that receives one or more Beam Failure Detection Reference Signals (BFD-RS) corresponding respectively to a plurality of panels; and a control unit that determines a new BFD-RS from a set of candidate BFD-RSs if the wireless link quality of at least some of the BFD-RSs among configured BFD-RSs is less than a specific threshold value. This embodiment of this disclosure makes it possible to appropriately perform beam failure detection or beam failure recovery even if a plurality of transmission points are used.

Description

Technical Field

[0001] The present disclosure relates to a terminal, a wireless communication method, a base station in a next-generation mobile communication system. 、 base station and system and relates thereto.

Background Art

[0002] In a Universal Mobile Telecommunications System (UMTS) network, Long Term Evolution (LTE) was standardized for the purpose of further high data rates, low latency, etc. (Non-Patent Document 1). Also, for the purpose of further large capacity and sophistication of LTE (Third Generation Partnership Project (3GPP) Release (Rel.) 8, 9), LTE-Advanced (3GPP Rel. 10-14) was standardized.

[0003] Successor systems to LTE (for example, also referred to as 5th generation mobile communication system (5G), 5G+ (plus), 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel. 15 and later, etc.) are also being considered.

[0004] In existing LTE systems (LTE Rel. 8-15), monitoring of radio link quality (Radio Link Monitoring (RLM)) is performed. When a Radio Link Failure (RLF) is detected from RLM, re-establishment of the Radio Resource Control (RRC) connection is requested of the User Equipment (UE).

Prior Art Documents

Non-Patent Documents

[0005] [Non-Patent Document 1] 3GPP TS 36.300 V8.12.0 "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)", April 2010 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] In future wireless communication systems (e.g., NR), it is considered to perform a procedure for detecting a beam failure and switching to another beam (a beam failure recovery (BFR) procedure, which may also be called BFR, etc.).

[0007] In Rel.15 NR, BFR is triggered when the quality of all reference signals for beam failure detection falls below a predetermined threshold. On the other hand, when the quality of some of the reference signals for beam failure detection falls below a predetermined threshold, it may be considered to determine a partial beam failure and perform beam failure recovery.

[0008] Also, in NR after Rel.17, it is also assumed to perform communication using a plurality of user equipment (UE) panels / plural transmission and reception points (TRPs). In this case, it is considered to perform beam failure detection in a plurality of UE panels / plural TRPs, but the problem is how to control beam failure detection or beam failure recovery in each UE panel / TRP. If beam failure detection or beam failure recovery in each UE panel / TRP cannot be appropriately controlled, there is a possibility of a decrease in communication throughput or deterioration of communication quality.

[0009] The present disclosure has been made in view of such a point, and a terminal and a wireless communication method capable of appropriately performing beam failure detection or beam failure recovery even when a plurality of transmission points are used 、 Base station and system is one of the purposes.

Means for Solving the Problems

[0010] A terminal according to an aspect of the present disclosure includes a receiving unit that receives Radio Resource Control (RRC) signaling for setting a plurality of sets of beam failure detection reference signals (BFD-RS) corresponding to each of a plurality of transmit-receive points (TRP), and at least one of the plurality of BFD-RS sets When beam failure recovery (BFR) is triggered for the BFD-RS set, a control unit that controls to transmit a Medium Access Control control element (MAC CE) for BFR and the MAC CE includes at least one octet including a field indicating an ID corresponding to a BFD-RS set in which a beam failure is detected, a field indicating a candidate RS ID or a reserved bit, and a field indicating the presence of the candidate RS ID It is characterized by this.

Effect of the Invention

[0011] According to an aspect of the present disclosure, beam failure detection or beam failure recovery can be appropriately performed even when a plurality of transmission points are used.

Brief Description of the Drawings

[0012]

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DETAILED DESCRIPTION OF THE INVENTION

[0013] (Beam Obstruction Detection) In NR, communication is performed using beamforming. For example, a UE and a base station (e.g., a gNB (gNodeB)) may use a beam (also referred to as a transmission beam, Tx beam, etc.) used for signal transmission and a beam (also referred to as a reception beam, Rx beam, etc.) used for signal reception.

[0014] When beamforming is used, since it is more susceptible to interference by obstacles, it is assumed that the radio link quality deteriorates. Due to the deterioration of the radio link quality, there is a risk that radio link failures (RLFs) occur frequently. When an RLF occurs, reconnection of the cell is required, so frequent occurrence of RLFs leads to deterioration of the system throughput.

[0015] In NR, in order to suppress the occurrence of RLFs, when the quality of a specific beam deteriorates, a procedure for switching to another beam (which may be called beam recovery (BR), beam failure recovery (BFR), L1 / L2 (Layer 1 / Layer 2) beam recovery, etc.) is performed. Note that the BFR procedure may simply be called BFR.

[0016] Note that beam failure (BF) in the present disclosure may be referred to as link failure.

[0017] FIG. 1 is a diagram showing an example of a beam recovery procedure in Rel. 15 NR. The number of beams, etc. are examples and are not limited thereto. In the initial state (step S101) of FIG. 1, the UE performs measurements based on a reference signal (RS) resource transmitted using two beams.

[0018] The RS may be at least one of a Synchronization Signal Block (SSB) and a Channel State Information RS (CSI-RS). Note that the SSB may also be referred to as an SS / PBCH (Physical Broadcast Channel) block or the like.

[0019] The RS may be at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), a Mobility Reference Signal (MRS), a signal included in the SSB, the SSB, the CSI-RS, a Demodulation Reference Signal (DMRS), a beam-specific signal, etc., or a signal configured by extending, modifying, etc. these. The RS measured in step S101 may be referred to as a Beam Failure Detection RS (BFD-RS), a RS for beam failure detection, etc.

[0020] In step S102, due to interference with the radio wave from the base station, the UE cannot detect the BFD-RS (or the reception quality of the RS deteriorates). Such interference may occur due to, for example, obstacles between the UE and the base station, fading, interference, etc.

[0021] When a predetermined condition is satisfied, the UE detects a beam failure. For example, the UE may detect the occurrence of a beam failure when the Block Error Rate (BLER) is less than the threshold for all of the set BFD-RS (BFD-RS resource setting). When the occurrence of a beam failure is detected, the lower layer (Physical (PHY) layer) of the UE may notify (indicate) the upper layer (MAC layer) of a beam failure instance.

[0022] Note that the criteria for judgment are not limited to BLER, and may also be the Layer 1 Reference Signal Received Power (L1-RSRP) in the physical layer. Also, instead of or in addition to RS measurement, beam failure detection may be performed based on a downlink control channel such as the Physical Downlink Control Channel (PDCCH). BFD-RS may be expected to be in Quasi-Co-Location (QCL) with the DMRS of the PDCCH monitored by the UE.

[0023] Here, QCL is an indicator showing the statistical properties of a channel. For example, when a certain signal / channel and another signal / channel are in a QCL relationship, it may mean that at least one of the Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (for example, spatial Rx parameter) is the same (QCL with respect to at least one of these) among these different multiple signals / channels.

[0024] Note that the spatial Rx parameter may correspond to the receiving beam of the UE (for example, the receiving analog beam), and the beam may be identified based on spatial QCL. QCL (or at least one element of QCL) in the present disclosure may be read as sQCL (spatial QCL).

[0025] Information regarding BFD-RS (for example, the index, resource, number, number of ports, precoding, etc. of the RS), information regarding beam failure detection (BFD) (for example, the above-mentioned threshold), etc. may be set (notified) to the UE using upper layer signaling or the like. The information regarding BFD-RS may also be called information regarding BFR resources, etc.

[0026] In the present disclosure, the upper layer signaling may be any one of, for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information, or a combination thereof.

[0027] The MAC signaling may use, for example, a MAC control element (MAC CE (Control Element)), a MAC PDU (Protocol Data Unit), etc. The broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), a Remaining Minimum System Information (RMSI), an Other System Information (OSI), etc.

[0028] When the MAC layer of the UE receives a beam failure instance notification from the PHY layer of the UE, it may start a predetermined timer (which may be called a beam failure detection timer). If the MAC layer of the UE receives the beam failure instance notification a certain number of times (for example, beamFailureInstanceMaxCount set by RRC) or more before the timer expires, it may trigger a BFR (for example, start any of the random access procedures described below).

[0029] The base station may determine that the UE has detected a beam failure when there is no notification from the UE or when it receives a predetermined signal (the beam recovery request in step S104) from the UE.

[0030] In step S103, for beam recovery, the UE starts searching for a new candidate beam for new communication use. The UE may select a new candidate beam corresponding to the said RS by measuring a predetermined RS. The RS measured in step S103 may be called, for example, New Candidate Beam Identification RS (NCBI-RS), CBI-RS, CB-RS (Candidate Beam RS), etc. The NCBI-RS may be the same as or different from the BFD-RS. Note that the new candidate beam may simply be called a candidate beam.

[0031] The UE may determine a beam corresponding to an RS that meets a predetermined condition as the new candidate beam. For example, the UE may determine a new candidate beam based on an RS among the set NCBI-RS for which the L1-RSRP exceeds a threshold. Note that the criterion for determination is not limited to the L1-RSRP. The L1-RSRP regarding the SSB may also be called the SS-RSRP. The L1-RSRP regarding the CSI-RS may also be called the CSI-RSRP.

[0032] Information regarding the NCBI-RS (such as the resource, number, number of ports, precoding, etc. of the RS), information regarding new candidate beam identification (NCBI) (such as the above-mentioned threshold), etc. may be set (notified) to the UE using upper layer signaling, etc. The information regarding the NCBI-RS may be obtained based on the information regarding the BFD-RS. The information regarding the NCBI-RS may also be called information regarding the NBCI resource, etc.

[0033] Note that the BFD-RS, NCBI-RS, etc. may be replaced by the Radio Link Monitoring RS (RLM-RS).

[0034] In step S104, the UE that has identified a new candidate beam transmits a Beam Failure Recovery reQuest (BFRQ). The beam failure recovery request may also be referred to as a beam recovery request signal, a beam failure recovery request signal, etc.

[0035] The BFRQ may be transmitted, for example, using at least one of a Physical Uplink Control Channel (PUCCH), a Physical Random Access Channel (PRACH), a Physical Uplink Shared Channel (PUSCH), or a configured grant (CG) PUSCH.

[0036] The BFRQ may include information on the new candidate beam identified in step S103. A resource for the BFRQ may be associated with the new candidate beam. The beam information may be notified using a Beam Index (BI), a port index of a predetermined reference signal, a resource index (for example, a CSI-RS Resource Indicator (CRI), an SSB Resource Indicator (SSBRI)), etc.

[0037] In Rel.15 NR, Contention-Based BFR (CB-BFR), which is a BFR based on a contention-based random access (RA) procedure, and Contention-Free BFR (CF-BFR), which is a BFR based on a contention-free random access procedure, are being considered. In CB-BFR and CF-BFR, the UE may transmit a preamble (RA preamble, also referred to as a Physical Random Access Channel (PRACH), RACH preamble, etc.) as the BFRQ using a PRACH resource.

[0038] In CB-BFR, the UE may transmit a preamble randomly selected from one or more preambles. On the other hand, in CF-BFR, the UE may transmit a preamble specifically assigned to the UE by the base station. In CB-BFR, the base station may assign the same preamble to multiple UEs. In CF-BFR, the base station may assign preambles to UEs individually.

[0039] Note that CB-BFR and CF-BFR may also be referred to as contention-based PRACH-based BFR (CBRA-BFR) and contention-free PRACH-based BFR (CFRA-BFR), respectively. CBRA-BFR may also be referred to as CBRA for BFR. CFRA-BFR may also be referred to as CFRA for BFR.

[0040] Regardless of whether it is CB-BFR or CF-BFR, information regarding the PRACH resource (RA preamble) may be notified, for example, by upper layer signaling (such as RRC signaling). For example, the information may include information indicating the correspondence between the detected DL-RS (beam) and the PRACH resource, and different PRACH resources may be associated with each DL-RS.

[0041] In step S105, the base station that has detected the BFRQ transmits a response signal (which may also be referred to as a gNB response, etc.) to the BFRQ from the UE. The response signal may include reconfiguration information (for example, configuration information of the DL-RS resource) for one or more beams.

[0042] The response signal may be transmitted, for example, in the UE common search space of the PDCCH. The response signal may be notified using PDCCH (DCI) scrambled by a cyclic redundancy check (CRC) with a UE identifier (for example, a cell-radio RNTI (C-RNTI)). The UE may determine at least one of the transmission beam and the reception beam to be used based on the beam reconfiguration information.

[0043] The UE may monitor the response signal based on at least one of a control resource set (CORESET) for BFR and a search space set for BFR.

[0044] Regarding CB-BFR, when the UE receives a PDCCH corresponding to its own C-RNTI, it may be determined that contention resolution has succeeded.

[0045] Regarding the process of step S105, a period for the UE to monitor a response from a base station (for example, a gNB) to the BFRQ may be set. The period may be referred to as, for example, a gNB response window, a gNB window, a beam recovery request response window, etc. If the UE does not detect a gNB response within the window period, it may retransmit the BFRQ.

[0046] In step S106, the UE may transmit a message indicating that the beam reconfiguration to the base station has been completed. The message may be transmitted, for example, by PUCCH or by PUSCH.

[0047] Beam recovery success (BR success) may represent, for example, the case where step S106 is reached. On the other hand, beam recovery failure (BR failure) may correspond to, for example, the case where the BFRQ transmission reaches a predetermined number of times or the Beam-failure-recovery-Timer expires.

[0048] Note that the numbers of these steps are only for explanatory purposes, and multiple steps may be grouped together or the order may be changed. Also, whether to perform BFR may be set for the UE using upper layer signaling.

[0049] (Beam Management) In Rel.15 NR, methods of Beam Management (BM) have been studied. In this beam management, beam selection is being studied based on the L1-RSRP reported by the UE. Changing (switching) the beam of a certain signal / channel may correspond to changing at least one of the TCI state and QCL assumption of the signal / channel.

[0050] The UE may report (transmit) the measurement results for beam management using the Physical Uplink Control Channel (PUCCH) or the Physical Uplink Shared Channel (PUSCH). The measurement results may be, for example, CSI including at least one of L1-RSRP, L1-RSRQ, L1-SINR, L1-SNR, etc.

[0051] The measurement results (e.g., CSI) reported for beam management may be referred to as beam measurement, beam measurement report, beam report (beam report), beam report CSI, etc.

[0052] CSI measurements for beam reports may include interference measurements. The UE may measure channel quality, interference, etc. using resources for CSI measurements and derive a beam report.

[0053] The beam report may include the result of at least one of channel quality measurement and interference measurement. The result of channel quality measurement may include, for example, L1-RSRP. The result of interference measurement may include L1-SINR, L1-SNR, L1-RSRQ, other interference-related indicators (e.g., any indicator other than L1-RSRP), etc.

[0054] The CSI report setting information may include the "report quantity" (which may be represented by the RRC parameter "reportQuantity"), which is information about the parameters to be reported in one report instance (e.g., one CSI). The report quantity is defined in the type of the ASN.1 object called "choice". Therefore, one of the parameters defined as the report quantity (cri-RSRP, ssb-Index-RSRP, etc.) is set.

[0055] For a UE in which the upper layer parameter included in the CSI report setting information (e.g., the RRC parameter "groupBasedBeamReporting" related to group-based beam reporting) is set to disabled, for each report setting, different beam measurement resource IDs (e.g., SSBRI, CRI) of the number of upper layer parameters included in the CSI report setting information (e.g., the RRC parameter "nrofReportedRS" indicating the number of reported RSs) and the measurement results (e.g., L1-RSRP) corresponding to each ID may be included in the beam report (one report instance).

[0056] For a UE with groupBasedBeamReporting set to enabled, for each reporting configuration, two different beam measurement resource IDs and two measurement results (e.g., L1-RSRP) corresponding to each ID may be included in the beam report. In other words, a UE with groupBasedBeamReporting set to enabled divides DL-RS (e.g., CSI-RS) into two groups and reports the ID and measurement value of the top RS in each group. Note that the two beam measurement resources (CSI-RS resource, SSB resource) may be received simultaneously by the UE using one spatial domain reception filter or may be received simultaneously using multiple simultaneous spatial domain reception filters.

[0057] In Rel.15 NR, among the reported quantities, cri-RSRP and ssb-Index-RSRP are related to beam management. A UE with cri-RSRP set as the reported quantity reports the CRI and the L1-RSRP corresponding to the CRI. A UE with ssb-Index-RSRP set as the reported quantity reports the SSBRI and the L1-RSRP corresponding to the CRI.

[0058] The CSI report can include one or more sets of CRI / SSBRI and RSRP. The number of these sets may be set by a higher layer parameter (e.g., the RRC parameter "nrofReportedRS") indicating the number of reference signal resources to be reported.

[0059] Regarding the L1-RSRP report, when nrofReportedRS is set to 1 (value 'n1'), RSRP#1, which is a field of a predetermined number of bits (e.g., m bits) indicating the L1-RSRP of the largest measurement value, is included in the CSI report. In Rel.15 NR, m = 7.

[0060] Regarding the L1-RSRP report, when nrofReportedRS is set to be greater than 1, or when groupBasedBeamReporting is enabled, the UE uses differential L1-RSRP based reporting. Specifically, the UE includes in the same CSI report (reporting instance) the RSRP#1 indicating the L1-RSRP of the largest measurement value and the differential (Differential) RSRP#k calculated with reference to the largest measurement value for the k-th (e.g., k = 2, 3, 4) largest L1-RSRP. Here, the differential RSRP#k may be a field of fewer bits (e.g., n bits) than the predetermined number. In Rel.15 NR, n = 4.

[0061] Note that when groupBasedBeamReporting is enabled, the UE includes RSRP#1 and differential RSRP#2 in the same CSI report.

[0062] Note that in NR after Rel.16, nrofReportedRS may be a value of 4 or more, and may be 4 or more. The CSI report may include combinations of 4 or more CRI / SSBRI and RSRP.

[0063] By the way, for future wireless communication systems (e.g., Rel.17 NR), extensions related to beam management for UEs with multiple panels (multi-panel), multiple transmission / reception points (multi-Transmission / Reception Point (TRP)), etc. (e.g., beam reports suitable for multiple TRPs) are being considered.

[0064] Since the above groupBasedBeamReporting can report for two groups in one report, it is suitable when multi-TRP transmission, multi-panel reception, etc. are applied. For example, it can be used to report the best beam of a certain TRP as RSRP#1 and the best beam of another TRP as differential RSRP#2.

[0065] In Release 16 NR, the introduction of L1-SINR reporting is being considered. Regarding the calculation of L1-SINR, the UE may set at least one of the NZP CSI-RS resource and the SSB resource for channel measurement, and at least one of the NZP CSI-RS resource and the CSI-IM resource for interference measurement.

[0066] A UE with cri-SINR set as the reporting quantity reports the CRI and the L1-SINR corresponding to the CRI. A UE with ssb-Index-SINR set as the reporting quantity reports the SSBRI and the L1-SINR corresponding to the CRI.

[0067] For a UE in which the upper layer parameters (e.g., the RRC parameter "groupBasedBeamReporting" for group-based beam reporting) included in the CSI reporting configuration information are set to disabled, for each report setting, different beam measurement resource IDs (e.g., SSBRI, CRI) of the number of upper layer parameters (e.g., the RRC parameter "nrofReportedRSForSINR" indicating the number of RSs reported for SINR) included in the CSI reporting configuration information, and the measurement results (e.g., L1-SINR) corresponding to each ID may be included in the beam report (one or more report instances).

[0068] For a UE in which groupBasedBeamReporting is set to enabled, for each report setting, two different beam measurement resource IDs and two measurement results (e.g., L1-SINR) corresponding to each ID may be included in the beam report. Note that the two beam measurement resources (CSI-RS resource, SSB resource) may be received simultaneously by the UE using one spatial domain reception filter, or may be received simultaneously using multiple simultaneous spatial domain reception filters.

[0069] Note that groupBasedBeamReporting for SINR reporting may be read as parameters such as "groupBasedBeamReportingForSINR".

[0070] For L1-SINR reporting, when nrofReportedRSForSINR is set to 1 (value 'n1'), SINR#1, which is a 7-bit field indicating the L1-SINR of the largest measurement value, is included in the CSI report.

[0071] For L1-SINR reporting, when nrofReportedRSForSINR is set to a value greater than 1, the UE uses differential L1-SINR-based reporting. Specifically, the UE includes in the same CSI report (reporting instance) SINR#1 indicating the L1-SINR of the largest measurement value and differential (Differential) SINR#k calculated with reference to the largest measurement value for the k-th (k = 2, 3, 4) largest L1-SINR (e.g., as the difference from the measurement value). Here, differential SINR#k may be a 4-bit field.

[0072] Note that SINR#1 may correspond to a value quantized to 7 bits with a step size of 0.5 dB in the range of -23 dB to 40 dB. Differential SINR#k may correspond to a value quantized to 4 bits with a step size of 1 dB. Note that the range, step size, etc. of each value are not limited to these.

[0073] (Partial beam obstruction) In NR from Rel.17 onwards, it is being considered to introduce partial beam obstruction that detects beam obstruction when the quality of some BFD-RS deteriorates.

[0074] When the quality of some of the BFD-RS deteriorates among the BFD-RS, the UE may indicate beam obstruction from the lower layer (PHY layer) to the upper layer (MAC layer).

[0075] A beam failure detected by some, rather than all, BFD-RSs may be referred to as a partial beam failure (PBF). Also, beam failure recovery performed based on PBF may be referred to as partial beam failure recovery (PBFR).

[0076] The BFRQ triggered based on PBF may be transmitted using PUCCH or PUSCH via an available or alive (not disconnected) UL beam / UL link.

[0077] The UE may perform PDCCH monitoring according to the previous TCI state setting until it receives at least one of reconfiguration of the state of the transmission configuration indication (Transmission Configuration Indication or Transmission Configuration Indicator (TCI)) (TCI state) and activation of the TCI state.

[0078] Here, the TCI state will be briefly described. The TCI state may indicate (or include) QCL information. The TCI state (and / or QCL information) may be, for example, information regarding the QCL between a target channel (or a reference signal (RS) for the channel) and another signal (e.g., another downlink reference signal (DL-RS)), and may include, for example, at least one of information regarding the DL-RS having a QCL relationship (DL-RS related information) and information indicating the QCL type (QCL type information).

[0079] The DL-RS related information may include at least one of information indicating DL-RS related to QCL and information indicating resources of the DL-RS. For example, when a plurality of reference signal sets (RS sets) are configured for a UE, the DL-RS related information may indicate at least one of the DL-RS having a QCL relationship with a channel (or ports for the channel) among the RSs included in the RS set, resources for the DL-RS, etc.

[0080] Information regarding QCL between a PDCCH (or DMRS antenna port related to the PDCCH) and a predetermined DL-RS may be referred to as a TCI state for the PDCCH, etc. The UE may determine the TCI state for the PDCCH (CORESET) based on RRC signaling and MAC CE.

[0081] For example, for a UE, one or more (K) TCI states may be configured for each CORESET by upper layer signaling. Also, the UE may activate one or more of the configured TCI states for each CORESET using MAC CE. The UE may perform monitoring (reception processing) of the CORESET based on the activated TCI state.

[0082] FIG. 2 is a diagram showing an example of partial beam obstruction. In the example of FIG. 2, the UE and the base station communicate using a plurality (here, four) of beams. The plurality of beams respectively correspond to different RSs (RS#1 to RS#4). In the example shown in FIG. 2, when the quality of some of the plurality of RSs (here, RS#1 and RS#2) becomes less than a specific threshold, partial beam obstruction is detected.

[0083] By the way, as described above, in Rel.15 and 16 NR, beam recovery is triggered when the quality of all BFD-RSs falls below a specific threshold (when there is a failure in all beams). When there is a failure in all beams, it is assumed that there is no UL beam (UL link) available for the UE. Therefore, in the BFRs that have been studied so far, BFRQ is transmitted using PRACH / PUCCH.

[0084] In addition, in NR after Rel.17, it is also assumed that communication is performed using a plurality of transmission and reception points (TRPs) / a plurality of UE panels. In this case, it is conceivable to perform partial beam failure detection in a plurality of TRPs / panels, but the problem is how to control the partial beam failure detection in each TRP or the beam failure recovery based on the partial beam failure detection.

[0085] Specifically, when the UE receives a plurality (e.g., two) of PDSCH / DMRS / CSI-RS / SSBs with different specific QCLs (e.g., QCL type D), the NW needs to recognize the case where the power / quality of the received signal falls below the threshold in any one of the plurality of UE panels.

[0086] Therefore, the inventors have conceived a method for appropriately controlling partial beam failure detection or beam failure recovery based on the partial beam failure detection when using one or more TRPs / panels.

[0087] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Each embodiment may be applied alone or in combination.

[0088] (Wireless communication method) In the present disclosure, the UE may be a UE that performs transmission and reception with a TRP using a plurality of panels. Each panel may correspond to a separate TRP, or one panel may correspond to a plurality of TRPs, or a plurality of panels may correspond to one TRP.

[0089] In this disclosure, the UE panel (or panel index) may correspond to a specific group. In this case, the UE may assume that the beams / RSs of each group are measured at each panel of the UE. The UE may assume that beams of multiple groups are received simultaneously (using different panels).

[0090] Also, in this disclosure, the TRP (or base station) panel (or panel index) may correspond to a specific group. In this case, the UE may assume that the beams / RSs of each group are transmitted from the panel of each TRP (or base station). The UE may assume that beams of multiple groups can be received simultaneously, or may assume that they cannot be received simultaneously.

[0091] In this disclosure, the TRP (or base station) may be mutually read as the panel of the TRP (or base station), the RS group, the antenna port group, the spatial relationship group, the QCL group, the TCI state group, the CORESET group, etc.

[0092] In this disclosure, when single DCI is applied, the nth TRP (n is an arbitrary integer (e.g., 1 or 2)) may correspond to the nth TCI state and the nth Code Division Multiplexing (CDM) group.

[0093] In this disclosure, when multiple DCIs are applied, the first TRP may correspond to a CORESET without a CORESETPoolIndex, or a CORESET with CORESETPoolIndex = 0. The second TRP may correspond to a CORESET with CORESETPoolIndex = 1.

[0094] In this disclosure, the UE panel may be mutually read as the RS group, the antenna port group, the spatial relationship group, the QCL group, the TCI state group, the CORESET group, etc.

[0095] In the present disclosure, a panel may be associated with a group index of an SSB / CSI-RS group. Also, in the present disclosure, a panel may be associated with a TRP. Also, in the present disclosure, a plurality of panels may be associated with a group index of group beam-based reporting. Also, in the present disclosure, a panel may be associated with a group index of an SSB / CSI-RS group for group beam-based reporting.

[0096] In the present disclosure, a panel may mean a plurality of TRPs, a panel of TRPs, or a panel of UEs.

[0097] In the present disclosure, a BFD RS in which a beam failure is detected, a failed BFD RS, a TRP in which a beam failure is detected, a failed TRP, a UE panel that has detected a beam failure, and a failed UE panel may be mutually interchangeable.

[0098] In the present disclosure, A / B may mean at least one of A and B. In the present disclosure, A / B / C may mean at least one of A, B, and C.

[0099] <First Embodiment> In the first embodiment, the configuration of a set of BFD RSs for a UE to perform BFD in communication with a plurality of TRPs will be described.

[0100] For a UE, a set of BFD RSs corresponding to a plurality of TRPs / panels may be set independently. Then, for the UE, a new set of beam RSs may be set for each TRP / panel from among the set of BFD RSs. Then, the UE may transmit information regarding the new set of beam RSs (or a new beam RS) to the NW.

[0101] For example, for a UE, N sets of BFD RSs (e.g., 2 sets), each corresponding to one of N (e.g., 2) TRPs / panels, may be configured. The UE may determine a new set of beam RSs for each TRP / panel from among the sets of BFD RSs.

[0102] Also, for a UE, a set of BFD RSs corresponding to a plurality of TRPs / panels may be commonly configured. At this time, the number of sets of BFD RSs that are commonly configured may be one or more. Next, for the UE, a new set of beam RSs common to the plurality of TRPs / panels may be configured from among the sets of BFD RSs. Next, the UE may transmit information regarding the new set of beam RSs (or a new beam RS) to the NW.

[0103] For example, for a UE, a set of BFD RSs corresponding to each of N TRPs / panels may be commonly configured. The UE may determine a new set of beam RSs common to each TRP / panel from among the sets of BFD RSs.

[0104] At this time, the association between the SSB / CSI-RS index and the TRP / panel index may be configured / notified to the UE as a BFR configuration (information regarding the BFR configuration). The BFR configuration may be configured / notified to the UE by upper layer signaling.

[0105] Also, the association between the SSB / CSI-RS index and the TRP / panel index may not be configured / notified to the UE. In this case, the UE may configure / notify the association as information regarding the configuration of group-based beam reporting.

[0106] Note that even when one or more sets of BFD RSs corresponding to a plurality of TRPs / panels are commonly configured for the UE, the BFD RSs included in the set may be respectively configured for different TRPs / panels.

[0107] Figures 3A and 3B are diagrams showing an example of the setting of a set of BFD RSs corresponding to a plurality of TRPs / panels for a UE. Figure 3A shows that for a certain UE, sets of BFD RSs corresponding to a plurality (here, two) of TRPs are each set. For TRP#1, SSB#X and SSB#Y are set as BFD RS set #1. For TRP#2, SSB#M and SSB#N are set as BFD RS set #2. Also, as a new candidate beam RS set #1 for TRP#1, SSBs #0 to #31 are set. As a new candidate beam RS set #2 for TRP#2, SSBs #32 to #63 are set.

[0108] In Figure 3A, when the UE detects a beam failure in at least one of TRP#1 and TRP#2, the UE may determine a newly used BFD RS from among the new candidate beam RS sets corresponding to the TRP for which beam recovery is required.

[0109] Figure 3B shows that for a certain UE, sets of BFD RSs corresponding to a plurality (here, two) of TRPs are commonly set. For TRP#1 and TRP#2, SSB#Q and SSB#W are set as the BFD RS set. Also, as a new candidate beam RS set for TRP#1 and TRP#2, SSBs #0 to #63 are set.

[0110] In Figure 3B, when the UE detects a beam failure in at least one of TRP#1 and TRP#2, the UE may determine a newly used BFD RS from among the new candidate beam RS sets corresponding to the TRP for which beam recovery is required.

[0111] Note that the number and arrangement of TRPs, the number and direction of panels (beams), the sets of BFD RSs, and the number of BFD RSs in the BFD RS sets in Figures 3A and 3B are merely examples and are not limited thereto.

[0112] According to the first embodiment above, even when the UE (or a UE having a plurality of panels) communicates with a plurality of TRPs, beam failure detection can be appropriately performed.

[0113] <Second Embodiment> In the second embodiment, the operation of the UE regarding beam failure recovery when beam failure (BF) is detected for at least one TRP among a plurality of TRPs will be described. Note that "when beam failure is detected for at least one TRP among a plurality of TRPs" may be read as "when BF is detected in at least one set of BFD RSs".

[0114] When BF is detected for at least one TRP / panel among a plurality of TRPs / panels, the UE may transmit a beam recovery request to other TRPs (using other panels).

[0115] When the NW (network, e.g., base station) does not recognize information regarding the UE's panel (referred to as case 1), the NW may consider that different sets of BFD RSs correspond to different TRPs / panels. The UE may notify the NW via an available link of at least one of the failed set of BFD RSs and a new candidate beam corresponding to the set. In this case, the association between the BFD RS set and the TRP may be set / notified to the UE / NW.

[0116] When the NW recognizes information regarding the UE's panel (e.g., panel index) (referred to as case 2), transmission / reception using the UE's panel may be set, or the UE may determine transmission / reception using the UE's panel and notify the NW of information regarding the UE's panel (e.g., UE panel index).

[0117] Note that the information about the UE panel notified by the UE to the NW may be transmitted as UE capability information (UE Capability).

[0118] At this time, if the NW does not recognize the information about the UE panel (for example, panel index), the UE may notify the NW via an available link of at least one of the set of failed BFD RSs and the corresponding new candidate beam in the same manner as when the NW does not recognize the information about the UE panel (for example, panel index).

[0119] Also, at this time, the UE may notify the NW via an available link of at least one of the index of the failed UE panel (or the set of failed BFD REs, the failed TRP), the new candidate beam of the failed UE panel, and the new candidate beam corresponding to the panel. In this case, the association between the BFD RS set and the UE panel may be set / notified to the UE / NW. Also, in this case, the UE may set / notify the association as information regarding the configuration of group-based beam reporting.

[0120] According to the second embodiment above, even when a beam failure is detected for at least one TRP / panel among a plurality of TRPs / panels, beam failure recovery can be appropriately performed.

[0121] <Third Embodiment> In the third embodiment, a method for controlling partial beam failure detection using upper layer signaling (for example, MAC CE) related to BFR being considered in Rel.16 NR will be described.

[0122] In Rel.16 NR, when the quality of all BFD RSs set for the UE becomes below a certain threshold, BFR is performed using MAC CE. On the other hand, from Rel.17 onwards, when the quality of all BFD RSs corresponding to a certain TRP / panel among the BFD RSs set for the UE becomes below a certain threshold, BFR may be performed using MAC CE.

[0123] In the present disclosure, the MAC CE for performing BFR may be referred to as the MAC CE for BFR, the BFR MAC CE. Also, in the present disclosure, the BFR MAC CE may simply be referred to as the MAC CE.

[0124] Also, in Rel.16 NR, it is considered that for each newly configured beam RS, the UE determines a beam with the best quality (e.g., the maximum L1-RSRP). On the other hand, after Rel.17, after BFD, the UE may determine a beam with the best quality (e.g., the maximum L1-RSRP) for each newly configured beam RS for each TRP / panel.

[0125] Also, the QCL for a signal / channel (e.g., PDCCH, PUCCH, PDSCH, PUSCH) may be updated along with the new beam configuration. In other words, the UE may perform BFD assuming that the QCL for the signal / channel is updated along with the new beam configuration. At this time, the QCL corresponding to a TRP / panel other than the failed TRP / panel may not be updated.

[0126] Note that whether information regarding the UE's panel (e.g., panel ID) is explicitly included in the report by the MAC CE may depend on whether it is Case 1 or Case 2 described in the second embodiment above.

[0127] Hereinafter, with reference to FIG. 4, the MAC CE operation based on partial beam obstruction for multiple TRPs (for a UE having multiple panels) will be described. FIG. 4 is a diagram showing an example of the MAC CE operation in partial beam obstruction by the UE and the base station. The UE and the base station may perform the MAC CE operation based on partial beam obstruction in the order of the following Step 1 and Step 2.

[0128] [Step 1] If BF is detected, a PUCCH-BFR (scheduling request (SR)) may be transmitted from the UE to the PCell / PSCell. The BF detection may be the case where beam failure (BF) for at least one TRP / panel is detected. The PUCCH-BFR may be set for each panel / RS set (group) / TRP of the UE, or may be set for each UE. Also, similar to the operations being considered in Rel.16, the PUCCH-BFR may not be set for each panel / RS set (group) / TRP of the UE, or may not be set for each UE. Then, a UL grant (DCI) for step 2 below may be transmitted from the PCell / PSCell to the UE.

[0129] Note that the setting of the above PUCCH-BFR may be omitted when performing BFD using multiple TRPs / panels.

[0130] [Step 2] After receiving the UL grant, a new candidate beam search is performed. Then, in addition to information about the component carrier (CC) for which beam failure was detected (failed) (e.g., CC index) and information about the new beam (e.g., beam index), the UE may use a MAC CE to transmit information about the failed UE panel (e.g., panel index) to the base station (PCell / PSCell) via the uplink channel (e.g., PUSCH). After that, after going through the BFR procedure, 28 symbols after BFR, the QCL of PDCCH / PUCCH / PDSCH / PUSCH may be updated to the new beam.

[0131] Note that in the case of Case 1 of the second embodiment above, the MAC CE may not include information about the failed UE panel (e.g., panel index).

[0132] Note that the PCell, PSCell, and SCell in this embodiment may be mutually interchangeable.

[0133] Also, in this embodiment, the information regarding the failed UE panel (e.g., panel index) may be the information regarding the failed TRP (e.g., TRP index), and the information regarding the new candidate beam associated with the UE panel / TRP (e.g., candidate RS ID).

[0134] 《First BFR MAC CE Configuration》 Hereinafter, the MAC CE (BFR MAC CE) configuration used in the BFR for notifying the information regarding the failed UE panel (e.g., panel ID) will be described. When the panel ID is included in the MAC CE, the panel ID may have a bit length of a specific number of bits (e.g., N bits).

[0135] A specific field of the BFR MAC CE before Rel.16 (existing) may be updated to a field for indicating the panel ID. The UE may assume that when partial beam failure detection is set, a specific field of the MAC CE is updated.

[0136] The BFR MAC CE before Rel.16 may include at least one of a bit field representing the cell in which the BF was detected, a reserved bit field, a candidate RS ID or a reserved bit field (which may simply be referred to as a candidate RS ID field), a BFD indication field for the SpCell, and a field indicating the presence of the candidate RS ID.

[0137] The reserved bit field may not be particularly used for information notification, or may be freely used. In the specification, it may be fixed to a predetermined value (e.g., 0).

[0138] Figures 5A and 5B are diagrams showing the configuration of the BFR MAC CE before Rel. 16. Figure 5A shows the case where the MAC CE is updated when it includes a field representing the cells in which BF is detected for cells with 7 or less. Figure 5B shows the case where the MAC CE is updated when it includes a field representing the cells in which BF is detected for cells with 32 or less.

[0139] In Figures 5A and 5B, the C n bit (n is an integer of 1 or more) is a bit field representing the cells in which BF is detected, the SP bit is a BFD indication field for the SpCell, the AC bit is a field indicating the presence of a candidate RS ID, and the R bit is a reserved bit. Hereinafter, in the present disclosure, the C n bit and the R bit are the same.

[0140] For example, at least a part of the field representing the cells in which BF of the existing MAC CE is detected may be updated to a field (panel ID field) for indicating the panel ID. The field may indicate the field of the cell ID of the serving cell. Note that the field may indicate the field of the cell ID that is not the serving cell (which may be simply referred to as "Cell ID").

[0141] Figures 6A and 6B are diagrams showing an example of the BFR MAC CE configuration including the panel ID. Figure 6A shows the case where the MAC CE is updated when it includes a field representing the cells in which BF is detected for cells with 7 or less. Figure 6B shows the case where the MAC CE is updated when it includes a field representing the cells in which BF is detected for cells with 32 or less.

[0142] In Figures 6A and 6B, the field representing the cells in which BF of the MAC CE is detected is updated to a field for indicating a panel ID having a bit length of 2 bits. The UE transmits the updated MAC CE to the NW, and the NW performs a beam failure recovery procedure based on the panel ID included in the MAC CE.

[0143] Also, for example, an existing MAC CE reserved bit field may be updated to a field for indicating a panel ID.

[0144] FIGS. 7A and 7B are diagrams showing other examples of the BFR MAC CE configuration including a panel ID. FIG. 7A shows a case where the MAC CE is updated when it includes a field representing cells in which BF is detected for cells of 7 or less. FIG. 7B shows a case where the MAC CE is updated when it includes a field representing cells in which BF is detected for cells of 32 or less.

[0145] Note that, regarding the diagrams showing the MAC CE configuration of the present disclosure, the size and arrangement of each field and the assignment of indexes to each field are merely examples and are not limited thereto.

[0146] In FIGS. 7A and 7B, the reserved bit field is updated to a field for indicating a panel ID having a bit length of 1 bit. Since the reserved bit field is included in the MAC CE for each octet corresponding to each cell, the panel ID can be notified for each cell. The UE transmits the updated MAC CE to the NW, and the NW performs beam failure recovery procedures based on the panel ID included in the MAC CE.

[0147] Note that, in FIGS. 6A and 6B, FIGS. 7A and 7B, the value of the ID of the candidate RS corresponding to the panel ID may be a global index or a local index. When the value of the ID of the candidate RS is a global index, for example, candidate RS IDs corresponding to panel ID #0 may be assigned #0 to #31, and candidate RS IDs corresponding to panel ID #1 may be assigned #32 to #63. Also, when the value of the ID of the candidate RS is a local index, for example, candidate RS IDs corresponding to each of panel ID #0 and panel ID #1 may be assigned #0 to #31.

[0148] The panel ID may be implicitly indicated by a specific field of the MAC CE before Rel. 16 (existing). The UE may assume that when partial beam obstruction detection is configured, the panel ID is indicated by a field of the existing MAC CE.

[0149] For example, the panel ID may be implicitly indicated by a candidate RS ID or a reserved bit field of the existing MAC CE. In other words, the candidate RS ID or the reserved bit field of the existing MAC CE may be a field associated with the panel ID.

[0150] Figures 8A and 8B are diagrams showing other examples of the MAC CE configuration including the panel ID. Figure 8A shows the case where the MAC CE is updated when a field representing the cell in which BF is detected for cells of 7 or less is included. Figure 8B shows the case where the MAC CE is updated when a field representing the cell in which BF is detected for cells of 32 or less is included.

[0151] In Figures 8A and 8B, the value of the candidate RS ID corresponding to the panel ID may be a global index. For example, for the candidate RS ID corresponding to panel ID #0, #0 to #31 are assigned, and for the candidate RS ID corresponding to panel ID #1, #32 to #63 are assigned.

[0152] In Figures 8A and 8B, the panel ID is implicitly indicated by the candidate RS ID field. For example, when the value of the candidate RS ID is a value corresponding to panel ID #0 (e.g., #0 to #31), the field indicates panel ID #0. Also, for example, when the value of the candidate RS ID is a value corresponding to panel ID #1 (e.g., #32 to #63), the field indicates panel ID #1. The UE uses the candidate RS ID field to implicitly notify the NW of the panel ID, and the NW performs beam obstruction recovery procedures based on the candidate RS ID field.

[0153] Note that the candidate RS IDs corresponding to each panel ID may partially overlap among multiple panels. When the candidate RS IDs corresponding to each panel ID partially overlap among multiple panels, information regarding the overlapping candidate RS IDs may be notified to the UE by upper layer signaling / physical layer signaling.

[0154] 《Second BFR MAC CE Configuration》 Hereinafter, a method of notifying, using the MAC CE prior to Rel.16 (existing), the occurrence of BF in all of a plurality of TRP / UE panels or the occurrence of BF in a part of a plurality of TRP / UE panels will be described.

[0155] When upper layer parameters (RRC parameters) regarding partial beam failure detection for a plurality of panels (a plurality of TRPs) are set for the UE, the UE may assume that a specific field of the existing MAC CE is changed to a field (which may be called a partial BFD indication field) indicating the occurrence of BF in all of the plurality of TRP / UE panels or the occurrence of BF in a part of the plurality of TRP / UE panels. The specific field may be a reserved bit field.

[0156] FIG. 9 is a diagram showing an example of the second BFR MAC CE configuration. FIG. 9 shows the configuration of the MAC CE when a field representing a cell in which BF has been detected for cells 7 or less is included. In FIG. 9, the PBFD bit represents the partial BFD indication field.

[0157] In FIG. 9, a certain reserved bit field is updated to the partial BFD indication field. The NW may recognize a partial beam failure based on the partial BFD indication field.

[0158] When the specific field indicates that BF has occurred in all of the multiple TRP / UE panels, the UE and the NW may perform the same BFR operation as in Rel. 16. When the specific field indicates that BF has occurred in a part of the multiple TRP / UE panels, the UE and the NW may perform the BFR operation assuming that the MAC CE is updated as described above. In this case, information about a new beam for the failed panel may be indicated by the candidate RS ID included in the MAC CE.

[0159] Also, when the specific field indicates that BF has occurred in all of the multiple TRP / UE panels, information about a new beam for a random panel / TRP may be indicated by the candidate RS ID included in the MAC CE.

[0160] Also, when the specific field indicates that BF has occurred in all of the multiple TRP / UE panels, information about a new beam for a specific panel / TRP may be indicated by the candidate RS ID included in the MAC CE. The specific panel / TRP may be the panel / TRP corresponding to the minimum panel ID / TRP ID.

[0161] Also, when the specific field indicates that BF has occurred in all of the multiple TRP / UE panels, the MAC CE may be extended as in Configuration 1 to Configuration 3 described below. Hereinafter, Configuration 2-1 to Configuration 2-3 show an 8-octet MAC CE (corresponding to 7 or fewer cells) as an example, but the number of octets (number of cells) is not limited to this.

[0162] [Configuration 2-1] Configuration 2-1 may include fields corresponding to each of the multiple TRP / panels. The fields corresponding to each of the multiple TRP / panels may each include a field representing the cell in which the BF of the MAC CE was detected, a reserved bit field, and a candidate RS ID field.

[0163] FIG. 10 is a diagram showing an example of Configuration 2-1 of an extended BFR MAC CE. In FIG. 10, the extended MAC CE includes fields corresponding to a plurality (here, two) of panels, that is, a field corresponding to Panel #0 and a field corresponding to Panel #1. The field corresponding to each panel includes a field representing a cell in which the BF of the MAC CE was detected, a reserved bit field, a candidate RS ID field, and a partial BFD indication field.

[0164] Note that the configuration of the BFR MAC CE shown in FIG. 10 may be a configuration in which a field representing a cell in which the BF was detected is set for each of a plurality of panels / TRPs.

[0165] In the example shown in FIG. 10, Octets #2 to #8 may each be seven octets corresponding to C 1 to C 7 for Panel #0. Also, Octets #10 to #16 may each be seven octets corresponding to C 1 to C 7 for Panel #1.

[0166] [Configuration 2-2] Configuration 2-2 may be such that the BFR MAC CE includes fields corresponding to each of a plurality of TRPs / panels. The field corresponding to a specific TRP / panel may include a field representing a cell in which the BF of the MAC CE was detected, a reserved bit field, and a candidate RS ID field. The field corresponding to a TRP / panel other than the specific TRP / panel may include a reserved bit field and a candidate RS ID field. The specific TRP / panel may be, for example, a TRP / panel corresponding to the smallest TRP ID / panel ID.

[0167] FIG. 11 is a diagram showing an example of Configuration 2-2 of the extended BFR MAC CE. In FIG. 11, the extended MAC CE includes fields corresponding to a plurality (here, two) of panels, that is, a field corresponding to Panel #0 and a field corresponding to Panel #1. The field corresponding to Panel #0 includes a field representing the cell in which the BF of the MAC CE was detected, a reserved bit field, and a candidate RS ID field. The field corresponding to Panel #1 includes a reserved bit field, a candidate RS ID field, and a partial BFD indication field.

[0168] Note that the configuration of the BFR MAC CE shown in FIG. 11 may be a configuration in which the field representing the cell in which the BF was detected is set commonly for a plurality of panels / TRPs.

[0169] In the example shown in FIG. 11, Octet #2 to Octet #8 may each be seven octets corresponding to C 1 to C 7 for Panel #0. Also, Octet #9 to Octet #15 may each be seven octets corresponding to C 1 to C 7 for Panel #1. That is, in this case, Octet #n and Octet #n + k (n, k are arbitrary integers (here, k = 7)) may correspond to the same cell.

[0170] [Configuration 2-3] Configuration 2-3 may be such that the MAC CE includes fields corresponding to each of a plurality of TRPs / panels. Regarding which TRP / panel among the plurality of TRPs / panels a particular field (for example, the reserved bit field) corresponds to, it may be indicated by the value of the field.

[0171] For example, when the value of a specific field (e.g., a reserved bit field) is the first value (e.g., 0), the candidate RS ID field adjacent to the specific field may indicate correspondence to a certain TRP / panel. Also, when the value of the specific field is the second value (e.g., 1), the candidate RS ID field adjacent to the specific field may indicate correspondence to another TRP / panel.

[0172] FIG. 12 is a diagram showing an example of Configuration 2-3 of the BFR MAC CE. In the example of FIG. 12, all the values of the reserved bit fields included in the MAC CE are 0. In this case, it is shown that all the candidate RS ID fields correspond to Panel #0.

[0173] Note that in the example shown in FIG. 12, Octets #2 to #8 may each be seven octets corresponding to C 1 from C 7 for Panel #0.

[0174] FIG. 13 is a diagram showing another example of Configuration 2-3 of the BFR MAC CE. In the example of FIG. 13, the values of the reserved bit fields of Octets #2 to #5 are 0, and the values of the reserved bit fields of Octets #6 to #8 are 1. In this case, it is shown that the candidate RS ID fields of Octets #2 to #5 correspond to Panel #0, and the candidate RS ID fields of Octets #6 to #8 correspond to Panel #1.

[0175] Note that in the example shown in FIG. 13, Octets #2 to #5 may each be four octets corresponding to C 1 from C 4 for Panel #0. Also, Octets #6 to #8 may each be three octets corresponding to C 1 from C 3 for Panel #1.

[0176] Also, when a specific field indicates a second value, the candidate RS ID field adjacent to the specific field may indicate correspondence to a certain TRP / panel until the value of the specific field below it switches from the first value to the second value. When the value of the specific field switches from the second value to the first value, the candidate RS ID field adjacent to the specific field may indicate correspondence to another TRP / panel until the value of the specific field below it switches from the first value to the second value.

[0177] FIG. 14 is a diagram showing another example of Configuration 2-3 of the extended BFR MAC CE. In the example of FIG. 14, the value of the reserved bit field in Octet #2 is 1, and the values of the reserved bit fields in Octets #3 to #5 are 0. Further, the value of the reserved bit field in Octet #6 is 1, and the values of the reserved bit fields in Octets #7 and #8 are 0. In this case, it is shown that the candidate RS ID fields from Octet #2 to Octet #5 correspond to Panel #0, and the candidate RS ID fields from Octet #6 to Octet #8 correspond to Panel #1.

[0178] Note that in the example shown in FIG. 14, each of Octets #2 to #5 may be four octets corresponding to C 1 to C 4 for Panel #0. Also, each of Octets #6 to #8 may be three octets corresponding to C 1 to C 3 for Panel #1.

[0179] Figure 15 is a diagram showing another example of Configuration 2-3 of the extended BFR MAC CE. In the example of Figure 15, for the MAC CE example, the value of the reserved bit field in Octet #2 is 1, and the values of the reserved bit fields from Octet #3 to Octet #8 are 0. Further, the value of the reserved bit field in Octet #9 is 1, and the values of the reserved bit fields from Octet #10 to Octet #15 are 0. In this case, it is shown that the complementary RS ID fields from Octet #2 to Octet #8 correspond to Panel #0, and the candidate RS ID fields from Octet #9 to Octet #15 correspond to Panel #1.

[0180] Note that in the example shown in Figure 15, Octets #2 to #8 may each be seven octets corresponding to C 1 to C 7 for Panel #0. Also, Octets #9 to #15 may each be seven octets corresponding to C 1 to C 7 for Panel #1.

[0181] 《Variations of MAC CE Configuration》 Whether the MAC CE is extended (whether octets are added) as described above may be indicated by a specific field included in the MAC CE. Specifically, the specific field may indicate whether to add octets including candidate RS IDs for a plurality of TRPs / panels.

[0182] The specific field may be a reserved bit field. Also, at this time, an association between the candidate RS configuration and a plurality of TRPs / panels may be made.

[0183] When the specific field included in the MAC CE is a first value (for example, 0), the MAC CE may include a bit field regarding one panel and may indicate information regarding candidate RSs for a failed panel.

[0184] Also, when a specific field included in the MAC CE is a second value (e.g., 1), the MAC CE may include a bit field related to a plurality of (e.g., two) panels (octets are added), and information regarding candidate RSs for the failed panel and other panels may be indicated.

[0185] According to the third embodiment above, it becomes possible to perform more appropriate control of partial beam failure detection by using the MAC CE.

[0186] (Wireless communication system) Hereinafter, the configuration of a wireless communication system according to an embodiment of the present disclosure will be described. In this wireless communication system, communication is performed using any one or a combination of the wireless communication methods according to the above embodiments of the present disclosure.

[0187] FIG. 16 is a diagram showing an example of the schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 may be a system that realizes communication using Long Term Evolution (LTE) standardized by the Third Generation Partnership Project (3GPP), 5th generation mobile communication system New Radio (5G NR), or the like.

[0188] In addition, the wireless communication system 1 may support dual connectivity (Multi-RAT Dual Connectivity (MR-DC)) between a plurality of Radio Access Technologies (RATs). MR-DC may include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), and the like.

[0189] In EN-DC, the base station (eNB) of LTE (E-UTRA) is the Master Node (MN), and the base station (gNB) of NR is the Secondary Node (SN). In NE-DC, the base station (gNB) of NR is the MN, and the base station (eNB) of LTE (E-UTRA) is the SN.

[0190] The wireless communication system 1 may support dual connectivity between a plurality of base stations within the same RAT (for example, NR-NR Dual Connectivity (NN-DC) where both the MN and the SN are base stations (gNBs) of NR).

[0191] The wireless communication system 1 may include a base station 11 that forms a relatively wide-coverage macro cell C1, and a base station 12 (12a - 12c) that is disposed within the macro cell C1 and forms a small cell C2 that is narrower than the macro cell C1. The user terminal 20 may be located within at least one cell. The arrangement, number, etc. of each cell and the user terminal 20 are not limited to the modes shown in the figures. Hereinafter, when the base stations 11 and 12 are not distinguished, they are collectively referred to as the base station 10.

[0192] The user terminal 20 may be connected to at least one of the plurality of base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) and dual connectivity (DC) using a plurality of component carriers (CCs).

[0193] Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band higher than 24 GHz (above-24 GHz). Note that the frequency bands, definitions, etc. of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a frequency band higher than FR2.

[0194] Also, the user terminal 20 may communicate using at least one of time division duplex (TDD) and frequency division duplex (FDD) in each CC.

[0195] The plurality of base stations 10 may be connected by wire (e.g., an optical fiber compliant with Common Public Radio Interface (CPRI), an X2 interface, etc.) or wirelessly (e.g., NR communication). For example, when NR communication is used as a backhaul between base stations 11 and 12, the base station 11 corresponding to the upper-level station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0196] The base station 10 may be connected to the core network 30 either via another base station 10 or directly. The core network 30 may include at least one of, for example, Evolved Packet Core (EPC), 5G Core Network (5GCN), Next Generation Core (NGC), etc.

[0197] The user terminal 20 may be a terminal corresponding to at least one of communication systems such as LTE, LTE-A, 5G, etc.

[0198] In the wireless communication system 1, a wireless access method based on Orthogonal Frequency Division Multiplexing (OFDM) may be used. For example, in at least one of the Downlink (DL) and the Uplink (UL), Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), etc. may be used.

[0199] The wireless access method may be referred to as a waveform. Note that in the wireless communication system 1, other wireless access methods (for example, other single-carrier transmission methods, other multi-carrier transmission methods) may be used for the UL and DL wireless access methods.

[0200] In the wireless communication system 1, as downlink channels, a Physical Downlink Shared Channel (PDSCH) shared by each user terminal 20, a Physical Broadcast Channel (PBCH), a Physical Downlink Control Channel (PDCCH), etc. may be used.

[0201] Also, in the wireless communication system 1, as uplink channels, a Physical Uplink Shared Channel (PUSCH) shared by each user terminal 20, a Physical Uplink Control Channel (PUCCH), a Physical Random Access Channel (PRACH), etc. may be used.

[0202] User data, upper layer control information, System Information Block (SIB), etc. are transmitted by the PDSCH. User data, upper layer control information, etc. may be transmitted by the PUSCH. Also, a Master Information Block (MIB) may be transmitted by the PBCH.

[0203] Lower layer control information may be transmitted by the PDCCH. The lower layer control information may include, for example, downlink control information (DCI) including scheduling information of at least one of the PDSCH and the PUSCH.

[0204] Note that the DCI for scheduling the PDSCH may be called DL assignment, DL DCI, etc., and the DCI for scheduling the PUSCH may be called UL grant, UL DCI, etc. Note that the PDSCH may be read as DL data, and the PUSCH may be read as UL data.

[0205] For PDCCH detection, a control resource set (CORESET) and a search space may be used. The CORESET corresponds to the resources for searching for DCI. The search space corresponds to the search area and search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor the CORESET associated with a certain search space based on the search space configuration.

[0206] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be referred to as a search space set. Note that the "search space", "search space set", "search space configuration", "search space set configuration", "CORESET", "CORESET configuration", etc. in the present disclosure may be mutually interchangeable.

[0207] Uplink control information (UCI) including at least one of channel state information (CSI), delivery confirmation information (e.g., also referred to as Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR) may be transmitted by PUCCH. A random access preamble for connection establishment with the cell may be transmitted by PRACH.

[0208] Note that in the present disclosure, downlink, uplink, etc. may be expressed without adding "link". Also, "Physical" may not be added at the beginning of various channels.

[0209] In the wireless communication system 1, a synchronization signal (Synchronization Signal (SS)), a downlink reference signal (Downlink Reference Signal (DL-RS)), etc. may be transmitted. In the wireless communication system 1, as the DL-RS, a cell-specific reference signal (Cell-specific Reference Signal (CRS)), a channel state information reference signal (Channel State Information Reference Signal (CSI-RS)), a demodulation reference signal (DeModulation Reference Signal (DMRS)), a positioning reference signal (Positioning Reference Signal (PRS)), a phase tracking reference signal (Phase Tracking Reference Signal (PTRS)), etc. may be transmitted.

[0210] The synchronization signal may be, for example, at least one of a primary synchronization signal (Primary Synchronization Signal (PSS)) and a secondary synchronization signal (Secondary Synchronization Signal (SSS)). A signal block including SS (PSS, SSS) and PBCH (and DMRS for PBCH) may be called an SS / PBCH block, an SS Block (SSB), etc. Note that SS, SSB, etc. may also be called reference signals.

[0211] Also, in the wireless communication system 1, as the uplink reference signal (Uplink Reference Signal (UL-RS)), a sounding reference signal (Sounding Reference Signal (SRS)), a demodulation reference signal (DMRS), etc. may be transmitted. Note that DMRS may also be called a UE-specific reference signal.

[0212] (Base station) FIG. 17 is a diagram showing an example of the configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transmission / reception unit 120, a transmission / reception antenna 130, and a transmission line interface 140. Note that one or more of the control unit 110, the transmission / reception unit 120, the transmission / reception antenna 130, and the transmission line interface 140 may be provided.

[0213] In this example, the functional blocks of the characteristic parts in the present embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. Some of the processes of each part described below may be omitted.

[0214] The control unit 110 controls the entire base station 10. The control unit 110 can be composed of a controller, a control circuit, etc., which are described based on the common knowledge in the technical field related to the present disclosure.

[0215] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission / reception, measurement, etc., using the transmission / reception unit 120, the transmission / reception antenna 130, and the transmission line interface 140. The control unit 110 may generate data, control information, a sequence, etc., to be transmitted as a signal, and transfer it to the transmission / reception unit 120. The control unit 110 may perform call processing (setting, release, etc.) of a communication channel, state management of the base station 10, management of radio resources, etc.

[0216] The transmission / reception unit 120 may include a baseband unit 121, a Radio Frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transmission / reception unit 120 can be composed of a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transmission / reception circuit, etc., which are described based on the common knowledge in the technical field related to the present disclosure.

[0217] The transceiver unit 120 may be configured as an integrated transceiver unit, or may be composed of a transmitter unit and a receiver unit. The transmitter unit may be composed of a transmission processing unit 1211 and an RF unit 122. The receiver unit may be composed of a reception processing unit 1212, an RF unit 122, and a measurement unit 123.

[0218] The transceiver antenna 130 can be composed of an antenna described based on the common understanding in the technical field related to the present disclosure, such as an array antenna.

[0219] The transceiver unit 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver unit 120 may receive the above-mentioned uplink channel, uplink reference signal, etc.

[0220] The transceiver unit 120 may form at least one of a transmission beam and a reception beam by using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc.

[0221] The transceiver unit 120 (transmission processing unit 1211) may perform processing of the Packet Data Convergence Protocol (PDCP) layer, processing of the Radio Link Control (RLC) layer (e.g., RLC retransmission control), processing of the Medium Access Control (MAC) layer (e.g., HARQ retransmission control), etc. on, for example, data and control information obtained from the control unit 110, and generate a bit string to be transmitted.

[0222] The transceiver unit 120 (transmission processing unit 1211) may perform transmission processing such as channel encoding (which may include error correction encoding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, digital-to-analog conversion, etc. on the bit sequence to be transmitted, and output a baseband signal.

[0223] The transceiver unit 120 (RF unit 122) may perform modulation to the radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transceiver antenna 130.

[0224] On the other hand, the transceiver unit 120 (RF unit 122) may perform amplification, filtering, demodulation to the baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 130.

[0225] The transceiver unit 120 (reception processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing, etc. to the acquired baseband signal, and acquire user data, etc.

[0226] The transmission / reception unit 120 (measurement unit 123) may perform measurements on the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, etc. based on the received signal. The measurement unit 123 may measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 110.

[0227] The transmission path interface 140 may transmit and receive signals (backhaul signaling) to and from devices included in the core network 30, other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0228] Note that the transmission unit and reception unit of the base station 10 in the present disclosure may be configured by at least one of the transmission / reception unit 120, the transmission / reception antenna 130, and the transmission path interface 140.

[0229] The transmission / reception unit 120 may transmit one or more reference signals for beam failure detection (Beam Failure Detection Reference Signal (BFD-RS)) corresponding to each of a plurality of panels. When the radio link quality of at least a part of the set BFD-RS set by the control unit 110 in the terminal is less than a specific threshold, the control unit 110 may control the reception of information regarding a new BFD-RS determined from the set of candidate BFD-RS (First Embodiment).

[0230] (User Terminal) FIG. 18 is a diagram showing an example of the configuration of a user terminal according to an embodiment. The user terminal 20 includes a control unit 210, a transmission / reception unit 220, and a transmission / reception antenna 230. Note that one or more of the control unit 210, the transmission / reception unit 220, and the transmission / reception antenna 230 may be provided.

[0231] In this example, the functional blocks of the characteristic parts 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. A part of the processing of each unit described below may be omitted.

[0232] The control unit 210 controls the entire user terminal 20. The control unit 210 can be composed of a controller, a control circuit, etc., which are described based on the common knowledge in the technical field related to the present disclosure.

[0233] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may control transmission, reception, measurement, etc. using the transmission / reception unit 220 and the transmission / reception antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals and transfer them to the transmission / reception unit 220.

[0234] The transmission / reception unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transmission / reception unit 220 can be composed of a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transmission / reception circuit, etc., which are described based on the common knowledge in the technical field related to the present disclosure.

[0235] The transmission / reception unit 220 may be configured as an integrated transmission / reception unit or may be composed of a transmission unit and a reception unit. The transmission unit may be composed of the transmission processing unit 2211 and the RF unit 222. The reception unit may be composed of the reception processing unit 2212, the RF unit 222, and the measurement unit 223.

[0236] The transmission / reception antenna 230 can be composed of an antenna described based on the common knowledge in the technical field related to the present disclosure, such as an array antenna or the like.

[0237] The transmission / reception unit 220 may receive the above-described downlink channel, synchronization signal, downlink reference signal, etc. The transmission / reception unit 220 may transmit the above-described uplink channel, uplink reference signal, etc.

[0238] The transmission / reception unit 220 may form at least one of a transmission beam and a reception beam by using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc.

[0239] The transmission / reception unit 220 (transmission processing unit 2211) may perform processing of the PDCP layer, processing of the RLC layer (e.g., RLC retransmission control), processing of the MAC layer (e.g., HARQ retransmission control), etc. on, for example, data and control information obtained from the control unit 210, and generate a bit string to be transmitted.

[0240] The transmission / reception unit 220 (transmission processing unit 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, digital-to-analog conversion, etc. on the bit string to be transmitted, and output a baseband signal.

[0241] Note that whether to apply DFT processing may be based on the setting of transform precoding. For a certain channel (e.g., PUSCH), when transform precoding is enabled, the transmission / reception unit 220 (transmission processing unit 2211) may perform DFT processing as the above-described transmission processing to transmit the channel using the DFT-s-OFDM waveform, or otherwise, it may not perform DFT processing as the above-described transmission processing.

[0242] The transmission / reception unit 220 (RF unit 222) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the signal in the radio frequency band via the transmission / reception antenna 230.

[0243] On the other hand, the transmission / reception unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the signal in the radio frequency band received by the transmission / reception antenna 230.

[0244] The transmission / reception unit 220 (reception processing unit 2212) may apply reception processing such as analog-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, and acquire user data, etc.

[0245] The transmission / reception unit 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurements, CSI measurements, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), reception quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement result may be output to the control unit 210.

[0246] Note that the transmission unit and reception unit of the user terminal 20 in the present disclosure may be configured by at least one of the transmission / reception unit 220 and the transmission / reception antenna 230.

[0247] The transmission / reception unit 220 may receive one or more reference signals for beam failure detection (Beam Failure Detection Reference Signal (BFD-RS)) corresponding to each of a plurality of panels. When the radio link quality of at least a part of the set BFD-RS among the set BFD-RS is less than a specific threshold, the control unit 210 may determine a new BFD-RS from the set of candidate BFD-RS (the first embodiment).

[0248] The set of candidate BFD-RSs may be a set common to the plurality of panels or a set set independently for each of the plurality of panels (first embodiment).

[0249] The control unit 210 may control to transmit at least one of a panel ID corresponding to at least a part of the BFD-RSs and information regarding a candidate beam corresponding to at least a part of the BFD-RSs (second embodiment).

[0250] The control unit 210 may control to transmit a media access control control element (MAC CE) including at least one of a panel ID field and a field associated with the panel ID (third embodiment).

[0251] (Hardware Configuration) Note that the block diagrams used in the description of the above embodiments show blocks of functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Also, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically combined device, or two or more physically or logically separated devices may be directly or indirectly (for example, using wired, wireless, etc.) connected and realized using these multiple devices. The functional block may be realized by combining software with the above one device or the above multiple devices.

[0252] Here, functions include, but are not limited to, judgment, decision, determination, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection determination, establishment, comparison, assumption, expectation, regarded as, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), assigning, etc. For example, a functional block (component) that enables transmission may be referred to as a transmitting unit, a transmitter, etc. In any case, as described above, the implementation method is not particularly limited.

[0253] For example, a base station, a user terminal, etc. in an embodiment of the present disclosure may function as a computer that performs the processing of the wireless communication method of the present disclosure. FIG. 19 is a diagram showing an example of the hardware configuration of a base station and a user terminal according to an embodiment. The above-described base station 10 and user terminal 20 may physically be 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, etc.

[0254] Note that in the present disclosure, terms such as device, circuit, device, section, unit, etc. can be read interchangeably with each other. The hardware configuration of the base station 10 and the user terminal 20 may be configured to include one or more of each device shown in the figure, or may be configured without including some devices.

[0255] For example, although only one processor 1001 is shown in the figure, there may be a plurality of processors. Also, the processing may be executed by one processor, or the processing may be executed by two or more processors simultaneously, sequentially, or using other methods. Note that the processor 1001 may be implemented by one or more chips.

[0256] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading a predetermined software (program) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, controlling communication via the communication device 1004, or controlling at least one of reading and writing data in the memory 1002 and the storage 1003.

[0257] The processor 1001 operates, for example, an operating system to control the entire computer. The processor 1001 may be constituted by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, a register, and the like. For example, at least a part of the above-described control unit 110 (210), transmission / reception unit 120 (220), etc. may be realized by the processor 1001.

[0258] Also, the processor 1001 reads a program (program code), software module, data, etc. from at least one of the storage 1003 and the communication device 1004 into 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 operations described in the above embodiments is used. For example, the control unit 110 (210) may be realized by a control program stored in the memory 1002 and operating in the processor 1001, and the same may be true for other functional blocks.

[0259] The memory 1002 is a computer-readable recording medium and may be constituted by at least one of, for example, Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EPROM (EEPROM), Random Access Memory (RAM), and other suitable storage media. The memory 1002 may be referred to as a register, a cache, a main memory (main storage device), etc. The memory 1002 can store a program (program code), a software module, etc. executable for implementing the wireless communication method according to an embodiment of the present disclosure.

[0260] The storage 1003 is a computer-readable recording medium and may be constituted by at least one of, for example, a flexible disk, a floppy (registered trademark) disk, a magneto-optical disk (e.g., a compact disc (Compact Disc ROM (CD-ROM), etc.), a digital versatile disc, a Blu-ray (registered trademark) disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, a stick, a key drive), a magnetic stripe, a database, a server, and other suitable storage media. The storage 1003 may be referred to as an auxiliary storage device.

[0261] The communication device 1004 is hardware (a transceiver 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, etc. The communication device 1004 may include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. in order to implement at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD). For example, the above-described transceiver unit 120 (220), the transceiver antenna 130 (230), etc. may be implemented by the communication device 1004. The transceiver unit 120 (220) may be physically or logically separated and implemented by a transmitter unit 120a (220a) and a receiver unit 120b (220b).

[0262] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives an external input. The output device 1006 is an output device (for example, a display, a speaker, a Light Emitting Diode (LED) lamp, etc.) that performs an output to the outside. Note that the input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

[0263] Also, each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus or may be configured using different buses for each device.

[0264] In addition, the base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), and a Field Programmable Gate Array (FPGA), 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 hardware components.

[0265] (Modification example) Regarding the terms described in the present disclosure and the terms necessary for understanding the present disclosure, they may be replaced with terms having the same or similar meanings. For example, channel, symbol, and signal (signal or signaling) may be read interchangeably with each other. Also, a signal may be a message. A reference signal may also be abbreviated as RS and may be called a Pilot, a pilot signal, etc. depending on the applicable standard. Also, a Component Carrier (CC) may be called a cell, a frequency carrier, a carrier frequency, etc.

[0266] The radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting the radio frame may be called a subframe. Further, the subframe may be composed of one or more slots in the time domain. The subframe may have a fixed time length (e.g., 1 ms) that does not depend on numerology.

[0267] Here, the new numerology may be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. The new numerology may indicate, for example, at least one of subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering process performed by a transceiver in the frequency domain, specific windowing process performed by a transceiver in the time domain, etc.

[0268] A slot may be composed of one or more symbols (such as Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.) in the time domain. Also, a slot may be a time unit based on the new numerology.

[0269] A slot may include a plurality of mini-slots. Each mini-slot may be composed of one or more symbols in the time domain. Also, a mini-slot may be called a sub-slot. A mini-slot may be composed of a smaller number of symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a mini-slot may be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot may be called PDSCH (PUSCH) mapping type B.

[0270] A radio frame, sub-frame, slot, mini-slot, and symbol all represent time units for signal transmission. Different names may be used for the radio frame, sub-frame, slot, mini-slot, and symbol respectively. Note that the time units such as frame, sub-frame, slot, mini-slot, and symbol in this disclosure may be read interchangeably with each other.

[0271] For example, 1 sub-frame may be called a TTI, or a plurality of consecutive sub-frames may be called a TTI, or 1 slot or 1 mini-slot may be called a TTI. That is, at least one of the sub-frame and the TTI may be the sub-frame (1 ms) in the existing LTE, or a period shorter than 1 ms (for example, 1 - 13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, mini-slot, etc. instead of a sub-frame.

[0272] Here, the TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, the base station performs scheduling to allocate radio resources (such as the frequency bandwidth and transmission power that can be used at each user terminal) to each user terminal in units of TTI. Note that the definition of the TTI is not limited to this.

[0273] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), code block, codeword, etc., or may be a processing unit for scheduling, link adaptation, etc. Note that when the TTI is given, the time interval (for example, the number of symbols) in which the transport block, code block, codeword, etc. are actually mapped may be shorter than the TTI.

[0274] When one slot or one mini-slot is called a TTI, one or more TTIs (i.e., one or more slots or one or more mini-slots) may be the minimum time unit for scheduling. Also, the number of slots (number of mini-slots) constituting the minimum time unit for the scheduling may be controlled.

[0275] A TTI having a time length of 1 ms may be called a normal TTI (TTI in 3GPP Rel.8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, etc. A TTI shorter than a 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 mini-slot, a sub-slot, a slot, etc.

[0276] Note that a long TTI (e.g., a normal TTI, a subframe, etc.) may be read as a TTI having a time length exceeding 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be read as a TTI having a TTI length less than that of the long TTI and equal to or more than 1 ms.

[0277] A resource block (Resource Block (RB)) is a resource allocation unit in the time domain and the frequency domain, and in the frequency domain, it may include one or a plurality of consecutive subcarriers. The number of subcarriers included in the RB may be the same regardless of the numerology, for example, it may be 12. The number of subcarriers included in the RB may be determined based on the numerology.

[0278] Also, the RB may include one or a plurality of symbols in the time domain, and may have a length of 1 slot, 1 mini-slot, 1 subframe, or 1 TTI. 1 TTI, 1 subframe, etc. may each be constituted by one or a plurality of resource blocks.

[0279] One or more RBs may also be referred to as Physical Resource Blocks (PRBs), Sub-Carrier Groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB pairs, etc.

[0280] Also, a resource block may be composed of one or more Resource Elements (REs). For example, 1 RE may be a radio resource area of 1 sub-carrier and 1 symbol.

[0281] A Bandwidth Part (BWP) (which may also be referred to as a partial bandwidth, etc.) may represent a subset of consecutive common resource blocks (common RBs) for a certain numerology in a certain carrier. Here, the common RB may be specified by the index of the RB based on the common reference point of the carrier. The PRB is defined in a certain BWP and may be numbered within the BWP.

[0282] The BWP may include a UL BWP (BWP for UL) and a DL BWP (BWP for DL). One or more BWPs may be set within one carrier for a UE.

[0283] At least one of the set BWPs may be active, and it may not be assumed that the UE transmits and receives a predetermined signal / channel outside the active BWP. Note that in the present disclosure, "cell", "carrier", etc. may be read as "BWP".

[0284] Note that the structures such as the above-described radio frame, subframe, slot, minislot, and symbol 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, the number of subcarriers included in an RB, and the number of symbols, symbol length, cyclic prefix (CP) length, etc. within a TTI can be variously changed.

[0285] Also, the information, parameters, etc. described in the present disclosure may be represented using absolute values, relative values from a predetermined value, or corresponding other information. For example, a radio resource may be indicated by a predetermined index.

[0286] The names used for parameters, etc. in the present disclosure are not limiting names in any way. Furthermore, mathematical formulas, etc. using these parameters may be different from those explicitly disclosed in the present disclosure. Since various channels (such as PUCCH, PDCCH, etc.) and information elements can be identified by any suitable names, the various names assigned to these various channels and information elements are not limiting names in any way.

[0287] The information, signals, etc. described in the present disclosure may be represented using any of various different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0288] Also, information, signals, etc. may be output from at least one of the upper layer to the lower layer and from the lower layer to the upper layer. Information, signals, etc. may be input and output via a plurality of network nodes.

[0289] The input / output information, signals, etc. may be stored in a specific location (e.g., memory) or may be managed using a management table. The information, signals, etc. to be input / output may be overwritten, updated, or appended. The output information, signals, etc. may be deleted. The input information, signals, etc. may be transmitted to other devices.

[0290] The notification of information is not limited to the aspects / embodiments described in the present disclosure and may be performed using other methods. For example, the notification of information in the present disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), upper layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB), etc.), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0291] Note that physical layer signaling may also be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. Also, RRC signaling may also be referred to as an RRC message and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc. Also, MAC signaling may be notified, for example, using a MAC Control Element (CE).

[0292] Also, the notification of predetermined information (e.g., the notification of "being X") is not limited to an explicit notification and may be performed implicitly (e.g., by not performing the notification of the predetermined information or by the notification of another piece of information).

[0293] The determination may be made based on a value represented by 1 bit (either 0 or 1), a boolean value represented by true or false, or a numerical comparison (e.g., comparison with a predetermined value).

[0294] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc., whether called software, firmware, middleware, microcode, a hardware description language, or by some other name.

[0295] Also, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, when software is transmitted from a website, server, or other remote source using at least one of wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), etc.) and wireless technologies (such as infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of the transmission medium.

[0296] The terms "system" and "network" used in the present disclosure may be used interchangeably. "Network" may mean the devices (e.g., base stations) included in the network.

[0297] In the present disclosure, terms such as "precoding", "precoder", "weight (precoding weight)", "Quasi-Co-Location (QCL)", "Transmission Configuration Indication state (TCI state)", "spatial relation", "spatial domain filter", "transmission power", "phase rotation", "antenna port", "antenna port group", "reference signal (Reference Signal (RS) port group)", "layer", "number of layers", "rank", "resource", "resource set", "resource group", "beam", "beam width", "beam angle", "antenna", "antenna element", "panel", "transmission / reception point" can be used interchangeably.

[0298] In the present disclosure, terms such as "Base Station (BS)", "radio base station", "fixed station", "NodeB", "eNB (eNodeB)", "gNB (gNodeB)", "access point", "Transmission Point (TP)", "Reception Point (RP)", "Transmission / Reception Point (TRP)", "panel", "cell", "sector", "cell group", "carrier", "component carrier" can be used interchangeably. The base station may also be referred to by terms such as macrocell, small cell, femtocell, picocell.

[0299] A base station can accommodate one or more (e.g., three) cells. When the base station accommodates a plurality of cells, the entire coverage area of the base station can be divided into a plurality of smaller areas, and each of the smaller areas can also provide communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The term "cell" or "sector" refers to a part or the whole of the coverage area of at least one of the base station and the base station subsystem that provides communication services in this coverage.

[0300] In the present disclosure, terms such as "Mobile Station (MS)", "user terminal", "User Equipment (UE)", and "terminal" can be used interchangeably.

[0301] A mobile station may also be called 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 appropriate term.

[0302] At least one of the base station and the mobile station may be called a transmission device, a reception device, a wireless communication device, etc. Note that at least one of the base station and the mobile station may be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), a moving body that moves without a driver (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanoid or non-humanoid). Note that at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0303] In addition, the base station in the present disclosure may be replaced by a user terminal. For example, for a configuration in which communication between a base station and a user terminal is replaced with communication between a plurality of user terminals (which may be referred to as, for example, Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.), each aspect / embodiment of the present disclosure may be applied. In this case, the functions of the above-described base station 10 may be configured to be functions of the user terminal 20. Also, terms such as "uplink" and "downlink" may be replaced with terms corresponding to inter-terminal communication (for example, "side"). For example, an uplink channel, a downlink channel, etc. may be replaced with a side channel.

[0304] Similarly, the user terminal in the present disclosure may be replaced by a base station. In this case, the functions of the above-described user terminal 20 may be configured to be functions of the base station 10.

[0305] In the present disclosure, operations assumed to be performed by a base station may, in some cases, be performed by its upper node. In a network including one or more network nodes having a base station, it is obvious that various operations performed for communication with a terminal can be performed by a base station, one or more network nodes other than the base station (for example, a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc., but not limited thereto), or a combination thereof.

[0306] Each aspect / embodiment described in the present disclosure may be used alone, in combination, or switched and used during execution. Also, the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in the present disclosure may be rearranged as long as there is no contradiction. For example, for the methods described in the present disclosure, the elements of various steps are presented using an exemplary order and are not limited to the specific order presented.

[0307] Each aspect / embodiment described in the present disclosure may be applied to systems using Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (x is, for example, an integer or a decimal), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), other suitable wireless communication methods, and next-generation systems extended based on these. Further, a combination of multiple systems (for example, a combination of LTE or LTE-A and 5G) may be applied.

[0308] The description "based on" used in the present disclosure does not mean "only based on" unless otherwise specified. In other words, the description "based on" means both "only based on" and "at least based on".

[0309] Any reference to an element using terms such as "first", "second", etc. used in this disclosure does not generally limit the quantity or order of those elements. These terms can be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a 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.

[0310] The term "determining" as used in this disclosure may encompass a wide variety of operations. For example, "determining" may be considered to be "judging", "calculating", "computing", "processing", "deriving", "investigating", "looking up, search, inquiry" (e.g., searching in a table, database, or another data structure), "ascertaining", etc.

[0311] Also, "determining" may be considered to be "receiving" (e.g., receiving information), "transmitting" (e.g., transmitting information), "input", "output", "accessing" (e.g., accessing data in memory), etc.

[0312] Also, "determining" may be considered to be "resolving", "selecting", "choosing", "establishing", "comparing", etc. That is, "determining" may be considered to be making some kind of operation.

[0313] Also, the term "determine (decide)" may be read as "assume", "expect", "consider", etc.

[0314] As used in this disclosure, the terms "connected" and "coupled", or any variations thereof, mean any direct or indirect connection or coupling between two or more elements, and can include the presence of one or more intermediate elements between two elements "connected" or "coupled" to each other. The coupling or connection between elements can be physical, logical, or a combination thereof. For example, "connected" may be read as "accessed".

[0315] In this disclosure, when two elements are connected, they can be considered to be "connected" or "coupled" to each other using one or more wires, cables, printed electrical connections, etc., and, as some non-limiting and non-exhaustive examples, electromagnetic energy having wavelengths in the radio frequency region, microwave region, optical (both visible and invisible) region, etc.

[0316] In this disclosure, the term "A and B are different" may mean that "A and B are different from each other". Note that the term may also mean that "A and B are each different from C". Terms such as "separate" and "coupled" may also be interpreted in the same way as "different".

[0317] In this disclosure, when the terms "include", "including", and variations thereof are used, these terms are intended to be inclusive in the same way as the term "comprising". Further, the term "or" as used in this disclosure is not intended to be an exclusive disjunction.

[0318] In the present disclosure, for example, when articles are added by translation, such as a, an, and the in English, the present disclosure may include that the nouns following these articles are in the plural form.

[0319] As described above, the invention according to the present disclosure has been described in detail. However, 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 variations 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 for illustrative purposes and does not bring any limiting meaning to the invention according to the present disclosure.

Claims

1. a receiving unit that receives Radio Resource Control (RRC) signaling for setting a plurality of sets of beam failure detection reference signals (BFD-RS) corresponding to each of a plurality of transmission and reception points (TRP); a control unit that controls to transmit a Medium Access Control control element (MAC CE) for BFR when beam failure recovery (BFR) is triggered for at least one set of the plurality of BFD-RS sets; and has, The MAC CE includes at least one octet including a field indicating an ID corresponding to the BFD-RS set in which a beam failure is detected, a field indicating a candidate RS ID or a reserved bit, and a field indicating the presence of the candidate RS ID. Terminal.

2. receiving Radio Resource Control (RRC) signaling for setting a plurality of sets of beam failure detection reference signals (BFD-RS) corresponding to each of a plurality of transmission and reception points (TRP); controlling to transmit a Medium Access Control control element (MAC CE) for BFR when beam failure recovery (BFR) is triggered for at least one set of the plurality of BFD-RS sets; and has, The MAC CE includes at least one octet including a field indicating an ID corresponding to the BFD-RS set in which a beam failure is detected, a field indicating a candidate RS ID or a reserved bit, and a field indicating the presence of the candidate RS ID. A wireless communication method for a terminal.

3. a transmitting unit that transmits Radio Resource Control (RRC) signaling for setting a plurality of sets of beam failure detection reference signals (BFD-RS) corresponding to each of a plurality of transmission and reception points (TRP); a control unit that controls to receive a Medium Access Control control element (MAC CE) for BFR when beam failure recovery (BFR) is triggered for at least one set of the plurality of BFD-RS sets; and has, The base station includes at least one octet including a field indicating an ID corresponding to a BFD-RS set in which a beam failure is detected, a field indicating a candidate RS ID or a reserved bit, and a field indicating the presence of the candidate RS ID. **Claim 4** A system having a terminal and a base station, wherein the terminal has a receiver that receives Radio Resource Control (RRC) signaling for setting a plurality of beam failure detection reference signal (BFD-RS) sets corresponding to respective ones of a plurality of transmit receive points (TRPs), and a controller that controls to transmit a Medium Access Control control element (MAC CE) for BFR when beam failure recovery (BFR) is triggered for at least one of the plurality of BFD-RS sets, the MAC CE includes at least one octet including a field indicating an ID corresponding to a BFD-RS set in which a beam failure is detected, a field indicating a candidate RS ID or a reserved bit, and a field indicating the presence of the candidate RS ID, and the base station has a transmitter that transmits the RRC signaling.

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