Terminal, wireless communication method, base station and system

Abstract

The present invention appropriately controls a beam to be applied after beam failure detection or beam failure recovery, even when a plurality of transmission / reception points are used. A terminal according to an aspect of the present disclosure comprises: a transmission unit for reporting information about a new candidate beam during beam failure recovery; a control unit for determining, after the beam failure recovery is completed, application of the new candidate beam as a quasi co-location assumption corresponding to a downlink shared channel, on the basis of whether a predetermined condition is satisfied; and a reception unit for receiving the downlink shared channel on the basis of the quasi co-location assumption.

Description

Terminal, wireless communication method and base station

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

[0002] Long Term Evolution (LTE) has been specified for the Universal Mobile Telecommunications System (UMTS) network with the aim of achieving higher data rates and lower latency (Non-Patent Document 1). Also, LTE-Advanced (3GPP Rel. 10-14) has been specified with the aim of achieving higher capacity and more advanced features than LTE (Third Generation Partnership Project (3GPP) Release (Rel.) 8, 9).

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

[0004] In existing LTE systems (LTE Rel. 8-15), radio link quality is monitored (Radio Link Monitoring (RLM)). When a Radio Link Failure (RLF) is detected by RLM, a request is made to a user equipment (UE) to re-establish a Radio Resource Control (RRC) connection.

[0005] 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

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

[0007] In NR Rel. 17 and later, it is assumed that a terminal (UE) will communicate using multiple transmission / reception points (TRPs) / UE panels. In this case, it is possible to perform beam failure detection at multiple TRPs / multiple UE panels, but the problem is how to control the beam (or QCL assumption / TCI state) applied after beam failure detection (BFD) or beam failure recovery (BFR). If the beam applied after beam failure detection or beam failure recovery at each TRP / UE panel cannot be appropriately controlled, there is a risk of a decrease in communication throughput or a deterioration in communication quality.

[0008] The present disclosure has been made in consideration of such points, and one of its objectives is to provide a terminal, a wireless communication method, and a base station that are capable of appropriately controlling the beam to be applied after beam failure detection or beam failure recovery, even when multiple transmission and reception points are used.

[0009] A terminal according to one aspect of the present disclosure includes a transmitting unit that reports information regarding a new candidate beam during beam failure recovery, a control unit that determines, after the beam failure recovery is completed, the application of the new candidate beam as a quasi-colocation assumption corresponding to a downlink shared channel based on whether a predetermined condition is satisfied, and a receiving unit that receives the downlink shared channel based on the quasi-colocation assumption.

[0010] According to one aspect of the present disclosure, even when multiple transmission and reception points are used, it is possible to appropriately control the beam to be applied after beam failure detection or beam failure recovery.

[0011] Fig. 1 is a diagram showing an example of a beam recovery procedure in Rel. 15 NR. Figs. 2A and 2B are diagrams showing an example of a scheduling offset between a PDCCH and a PDSCH. Figs. 3A and 3B are diagrams showing an example of a QCL assumption used for a PDSCH according to this embodiment. Figs. 4A and 4B are diagrams showing another example of a QCL assumption used for a PDSCH according to this embodiment. Figs. 5A and 5B are diagrams showing another example of a QCL assumption used for a PDSCH according to this embodiment. Fig. 6 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. Fig. 7 is a diagram showing an example of a configuration of a base station according to an embodiment. Fig. 8 is a diagram showing an example of a configuration of a user terminal according to an embodiment. Fig. 9 is a diagram showing an example of a hardware configuration of a base station and a user terminal according to an embodiment. Fig. 10 is a diagram showing an example of a vehicle according to an embodiment.

[0012] (Beam Obstacle 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 used to transmit a signal (also referred to as a transmit beam, Tx beam, etc.) and a beam used to receive a signal (also referred to as a receive beam, Rx beam, etc.).

[0013] When beamforming is used, it is expected that radio link quality will deteriorate due to increased susceptibility to interference from obstacles. This deterioration in radio link quality may lead to frequent radio link failures (RLFs). Since RLFs require cell reconnection, frequent RLFs will result in degradation of system throughput.

[0014] In NR, in order to suppress the occurrence of RLF, 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 also be simply called BFR.

[0015] Note that the beam failure (BF) in this disclosure may also be referred to as a link failure.

[0016] Figure 1 shows an example of a beam recovery procedure in Rel. 15 NR. The number of beams is merely an example and is not limited to this. In the initial state (step S101) of Figure 1, the UE performs measurements based on reference signal (RS) resources transmitted using two beams.

[0017] The RS may be at least one of a synchronization signal block (SSB) and a channel state measurement RS (Channel State Information RS (CSI-RS)). The SSB may also be called an SS / PBCH (Physical Broadcast Channel) block.

[0018] 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 an SSB, an SSB, a CSI-RS, a Demodulation Reference Signal (DMRS), a beam-specific signal, etc., or a signal configured by extending or modifying any of these. The RS measured in step S101 may also be called an RS for beam failure detection (Beam Failure Detection RS (BFD-RS)), an RS for use in a beam recovery procedure (BFR-RS), etc.

[0019] In step S102, the UE cannot detect the BFD-RS (or the reception quality of the RS deteriorates) due to interference with the radio waves from the base station. Such interference can occur due to, for example, obstacles, fading, interference, etc. between the UE and the base station.

[0020] The UE detects a beam failure when a predetermined condition is satisfied. For example, the UE may detect the occurrence of a beam failure when the block error rate (BLER) is less than a threshold for all configured BFD-RSs (BFD-RS resource configurations). When the occurrence of a beam failure is detected, a lower layer (physical (PHY) layer) of the UE may notify (indicate) a beam failure instance to an upper layer (MAC layer).

[0021] The criteria for the determination are not limited to BLER, but may be 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 (Physical Downlink Control Channel (PDCCH)). The BFD-RS may be expected to be quasi-co-located (QCL) with the DMRS of the PDCCH monitored by the UE.

[0022] Here, the QCL is an index indicating the statistical properties of a channel. For example, if a signal / channel has a QCL relationship with another signal / channel, it may mean that it can be assumed that at least one of a Doppler shift, a Doppler spread, an average delay, a delay spread, and a spatial parameter (e.g., a spatial Rx parameter) is the same between these different signals / channels (i.e., the QCL is true for at least one of these).

[0023] The spatial reception parameters may correspond to a reception beam (e.g., a reception analog beam) of the UE, and the beam may be identified based on a spatial QCL. The QCL (or at least one element of the QCL) in the present disclosure may be replaced with sQCL (spatial QCL).

[0024] Information about BFD-RS (e.g., RS index, resource, number, number of ports, precoding, etc.), information about beam failure detection (BFD) (e.g., the above-mentioned threshold), etc. may be configured (notified) to the UE using higher layer signaling, etc. The information about BFD-RS may also be referred to as information about BFR resources, etc.

[0025] In the present disclosure, higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, and the like, or a combination thereof.

[0026] The MAC signaling may use, for example, a MAC Control Element (CE), a MAC Protocol Data Unit (PDU), etc. The broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0027] When a beam failure instance notification is received from the UE's PHY layer, the UE's upper layer (e.g., MAC layer) may start a predetermined timer (which may be called a beam failure detection timer). If the UE's MAC layer receives a certain number of beam failure instance notifications (e.g., beamFailureInstanceMaxCount configured in RRC) before the timer expires, the UE's MAC layer may trigger a BFR (e.g., start one of the random access procedures described below).

[0028] The base station may determine that the UE has detected a beam failure if there is no notification from the UE or if it receives a predetermined signal (beam recovery request in step S104) from the UE.

[0029] In step S103, the UE starts searching for a new candidate beam to be used for new communication in order to recover the beam. The UE may select a new candidate beam corresponding to a predetermined RS by measuring the RS. The RS measured in step S103 may be referred to as a new candidate RS, an RS for identifying a new candidate beam, an NCBI-RS (New Candidate Beam Identification RS), an RS for new beam identification, an RS for new beam identification, an NBI-RS (New Beam Identification RS), a CBI-RS (Candidate Beam Identification RS), a CB-RS (Candidate Beam RS), or the like. The NBI-RS may be the same as or different from the BFD-RS. Note that the new candidate beam may simply be referred to as a new beam, a candidate beam, or a candidate RS.

[0030] The UE may determine a beam corresponding to an RS that satisfies a predetermined condition as a new candidate beam. The UE may determine a new candidate beam, for example, based on an RS among the configured NBI-RSs whose L1-RSRP exceeds a threshold. Note that the criteria for determination are not limited to L1-RSRP. The L1-RSRP related to SSB may be referred to as SS-RSRP. The L1-RSRP related to CSI-RS may be referred to as CSI-RSRP.

[0031] Information about the NBI-RS (e.g., RS resources, number, number of ports, precoding, etc.), information about the new beam identification (NBI) (e.g., the above-mentioned threshold), etc. may be configured (notified) to the UE using higher layer signaling, etc. Information about the new candidate RS (or NBI-RS) may be acquired based on information about the BFD-RS. Information about the NBI-RS may be referred to as information about NBI resources, etc.

[0032] Note that BFD-RS, NBI-RS, etc. may be interchangeably read as Radio Link Monitoring RS (RLM-RS).

[0033] In step S104, the UE that has identified the new candidate beam transmits a beam failure recovery request (BFRQ). The beam recovery request may also be referred to as a beam recovery request signal, a beam failure recovery request signal, or the like.

[0034] The BFRQ may be transmitted using, for example, at least one of an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), an uplink shared channel (Physical Uplink Shared Channel (PUSCH)), and a configured grant (CG) PUSCH.

[0035] The BFRQ may include information of the new candidate beam / new candidate RS identified in step S103. Resources 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, an RS index, a resource index (e.g., a CSI-RS Resource Indicator (CRI) or an SSB Resource Indicator (SSBRI)), etc.

[0036] In Rel. 15 NR, CB-BFR (Contention-Based BFR), which is a BFR based on a contention-based random access (RA) procedure, and CF-BFR (Contention-Free 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 use the PRACH resource to transmit a preamble (also referred to as an RA preamble, a random access channel (Physical Random Access Channel (PRACH)), a RACH preamble, etc.) as a BFRQ.

[0037] In CB-BFR, a UE may transmit a preamble randomly selected from one or more preambles. On the other hand, in CF-BFR, a UE may transmit a preamble assigned specifically to the UE by the base station. In CB-BFR, a base station may assign the same preamble to multiple UEs. In CF-BFR, a base station may assign a preamble individually to each UE.

[0038] Note that CB-BFR and CF-BFR may be referred to as CB PRACH-based BFR (contention-based PRACH-based BFR (CBRA-BFR)) and CF PRACH-based BFR (contention-free PRACH-based BFR (CFRA-BFR)), respectively. CBRA-BFR may be referred to as CBRA for BFR. CFRA-BFR may be referred to as CFRA for BFR.

[0039] Regardless of whether CB-BFR or CF-BFR is used, information about the PRACH resource (RA preamble) may be notified, for example, by higher layer signaling (such as RRC signaling). For example, the information may include information indicating a correspondence relationship between the detected DL-RS (beam) and the PRACH resource, and a different PRACH resource may be associated with each DL-RS.

[0040] In step S105, the base station that detected the BFRQ transmits a response signal (which may be referred to as a gNB response, etc.) to the BFRQ from the UE. The response signal may include reconfiguration information (e.g., DL-RS resource configuration information) for one or more beams.

[0041] The response signal may be transmitted, for example, in a UE common search space of the PDCCH. The response signal may be signaled using a PDCCH (DCI) scrambled with a cyclic redundancy check (CRC) by a UE identifier (e.g., a Cell-Radio RNTI (C-RNTI)). The UE may determine at least one of a transmit beam and a receive beam to use based on the beam reconfiguration information.

[0042] 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.

[0043] For CB-BFR, contention resolution may be determined to be successful if the UE receives a PDCCH corresponding to its own C-RNTI.

[0044] Regarding the processing of step S105, a period for the UE to monitor a response from a base station (e.g., a gNB) to the BFRQ may be set. This period may be referred to as, for example, a gNB response window, a gNB window, a beam recovery request response window, etc. If no gNB response is detected within this window period, the UE may retransmit the BFRQ.

[0045] In step S106, the UE may transmit a message indicating that the beam reconfiguration is complete to the base station. The message may be transmitted, for example, via the PUCCH or the PUSCH.

[0046] A beam recovery success (BR success) may indicate, for example, that step S106 has been reached, whereas a beam recovery failure (BR failure) may indicate, for example, that a predetermined number of BFRQ transmissions have been made or that a beam-failure-recovery-timer has expired.

[0047] Rel. 15 supports the use of a random access procedure to perform a beam recovery procedure (e.g., BFRQ notification) in response to a beam failure detected in an SpCell (PCell / PSCell).

[0048] On the other hand, Rel. 16 supports a beam recovery procedure (e.g., BFRQ notification (step S104 in FIG. 1)) for a beam failure detected in an SCell, using at least one of a PUCCH (e.g., a scheduling request (SR)) transmission for BFR and a MAC CE (e.g., an UL-SCH) transmission for BFR. For example, the UE may transmit information about the beam failure using two MAC CE-based steps. The information about the beam failure may include information about the cell in which the beam failure was detected and information about a new candidate beam (or a new candidate RS index).

[0049] [Step 1] If BFR is detected, a PUCCH-BFR (Scheduling Request (SR)) may be transmitted from the UE to the PCell / PSCell.

[0050] PUCCH-BFR may be referred to as PUCCH-SR, PUCCH-SR for BFR, or PUCCH for SR. Then, a UL grant (DCI) for the following step 2 may be transmitted from the PCell / PSCell to the UE. When a beam failure is detected and a MAC CE (or UL-SCH) for transmitting information about a new candidate beam exists, step 1 (e.g., PUCCH transmission) may be omitted and step 2 (e.g., MAC CE transmission) may be performed.

[0051] [Step 2] Next, the UE may transmit information about the cell where beam failure was detected (failed) (e.g., cell index) and information about the new candidate beam to the base station (PCell / PSCell) via an uplink channel (e.g., PUSCH) using a MAC CE. After that, through the BFR procedure, the QCL of the PDCCH / PUCCH / PDSCH / PUSCH may be updated to the new beam after a predetermined period (e.g., 28 symbols) after receiving a response signal from the base station.

[0052] Note that the numbers of these steps are for illustrative purposes only, and multiple steps may be combined or the order may be reversed. Furthermore, whether to perform BFR may be configured in the UE using higher layer signaling.

[0053] (Spatial relationship information) In NR, the UE controls the transmission processing (e.g., at least one of transmission, mapping, precoding, modulation, and encoding) of at least one of the uplink signals and channels (also referred to as signals / channels) based on a predetermined spatial relationship.

[0054] The spatial relationship that applies to a given signal / channel may be specified by Spatial Relation Information (SRI) that is signaled (configured) using higher layer signaling.

[0055] In the present disclosure, the higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, etc., or a combination thereof.

[0056] The MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. The broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0057] For example, in Rel-15 NR, spatial relationship information (RRC "PUCCH-SpatialRelationInfo" information element) between a predetermined reference signal (Reference Signal (RS)) and an uplink control channel (Physical Uplink Control Channel (PUCCH)) may be included in PUCCH configuration information (RRC "PUCCH-Config" information element) and configured in the UE.

[0058] The specified RS may be at least one of a Synchronization Signal Block (SSB), a Channel State Information-Reference Signal (CSI-RS), and a Sounding Reference Signal (SRS).

[0059] The configured SRI may include an SRI Identifier (ID) for identifying the SRI. The SRI may also include at least one of an SSB index, a CSI-RS resource ID, and an SRS resource ID as an index of the predetermined RS. The spatial relationship information may also include a serving cell index, a bandwidth part (BWP) ID, etc., corresponding to the predetermined RS.

[0060] In the present disclosure, the terms index, ID, indicator, resource ID, etc. may be interchangeable.

[0061] When the UE is configured with spatial relationship information regarding the SSB or CSI-RS and the PUCCH, the UE may transmit the PUCCH using the same spatial domain filter as the spatial domain filter for receiving the SSB or CSI-RS. That is, in this case, the UE may assume that the UE receiving beam for the SSB or CSI-RS and the UE transmitting beam for the PUCCH are the same.

[0062] When the UE is configured with spatial relationship information regarding the SRS and the PUCCH, the UE may transmit the PUCCH using the same spatial domain filter as the spatial domain filter for transmitting the SRS, i.e., in this case, the UE may assume that the UE transmission beam for the SRS and the UE transmission beam for the PUCCH are the same.

[0063] Note that the spatial domain filter for transmission by the base station, the downlink spatial domain transmission filter, and the transmission beam of the base station may be interchangeable. The spatial domain filter for reception by the base station, the uplink spatial domain receive filter, and the reception beam of the base station may be interchangeable.

[0064] Furthermore, the spatial domain filter for UE transmission, the uplink spatial domain transmission filter, and the UE transmission beam may be interchangeable. The spatial domain filter for UE reception, the downlink spatial domain receive filter, and the UE reception beam may be interchangeable.

[0065] The UE may configure the SRI for each PUCCH configuration (PUCCH-Config). The SRI configured by the PUCCH configuration may be applied to all PUCCH resources configured by the PUCCH configuration.

[0066] If more than one SRI for PUCCH is configured, the UE may control that one PUCCH SRI is active for one PUCCH resource at a time based on the PUCCH spatial relation Activation / Deactivation MAC CE.

[0067] (Multi-TRP PDSCH) In NR, one or more transmission / reception points (Transmission / Reception Points (TRPs)) (multi-TRPs (MTRPs)) are considered to perform DL transmission to a UE using one or more panels (multi-panels). Also, it is considered that a UE performs UL transmission to one or more TRPs using one or more panels.

[0068] Note that multiple TRPs may correspond to the same cell identifier (cell identifier (ID)) or different cell IDs. The cell ID may be a physical cell ID or a virtual cell ID.

[0069] Multi-TRPs (e.g., TRPs #1 and #2) may be connected by ideal / non-ideal backhauls to exchange information, data, etc. Each TRP of a multi-TRP may transmit a different code word (CW) and a different layer. Non-Coherent Joint Transmission (NCJT) may be used as a form of multi-TRP transmission.

[0070] In the NCJT, for example, TRP#1 modulates and layer-maps a first codeword to transmit a first PDSCH using a first number of layers (e.g., two layers) with a first precoding, and TRP#2 modulates and layer-maps a second codeword to transmit a second PDSCH using a second number of layers (e.g., two layers) with a second precoding.

[0071] Note that multiple PDSCHs (multi-PDSCHs) that are non-coherent may be defined as partially or completely overlapping in time and / or frequency domains, i.e., a first PDSCH from a first TRP and a second PDSCH from a second TRP may overlap in time and / or frequency resources.

[0072] The first PDSCH and the second PDSCH may be assumed to be not quasi-co-located (QCL). Reception of multiple PDSCHs may be interpreted as simultaneous reception of PDSCHs that are not of a certain QCL type (e.g., QCL type D).

[0073] Multiple PDSCHs from multiple TRPs (which may be referred to as multiple PDSCHs) may be scheduled using one DCI (single DCI, single PDCCH) (single-master mode, single-DCI based multi-TRP). Multiple PDSCHs from multiple TRPs may be scheduled using multiple DCIs (multiple DCI, multiple PDCCHs) (multi-master mode, multi-DCI based multi-TRP).

[0074] In URLLC for multi-TRP, it is considered that PDSCH (transport block (TB) or codeword (CW)) repetition across multi-TRP is supported. Repetition schemes (URLLC schemes, e.g., Schemes 1, 2a, 2b, 3, and 4) across multi-TRP in the frequency domain, layer (spatial) domain, or time domain are supported. In Scheme 1, multiple PDSCHs from multi-TRP are space division multiplexed (SDM). In Schemes 2a and 2b, PDSCHs from multi-TRP are frequency division multiplexed (FDM). In Scheme 2a, the redundancy version (RV) is the same for multi-TRP. In Scheme 2b, the RVs for multi-TRP may be the same or different. In schemes 3 and 4, multiple PDSCHs from multiple TRPs are time division multiplexed (TDM). In scheme 3, multiple PDSCHs from multiple TRPs are transmitted in one slot. In scheme 4, multiple PDSCHs from multiple TRPs are transmitted in different slots.

[0075] Such a multi-TRP scenario allows for more flexible transmission control using good quality channels.

[0076] In order to support multi-TRP transmission within a cell (with the same cell ID) and between cells (with different cell IDs) based on multiple PDCCHs, in the RRC configuration information for linking multiple pairs of PDCCHs and PDSCHs with multiple TRPs, one control resource set (CORESET) in the PDCCH configuration information (PDCCH-Config) may correspond to one TRP.

[0077] If at least one of the following conditions 1 and 2 is satisfied, the UE may determine that the transmission is a multi-TRP transmission based on the multi-DCI. In this case, the TRP may be replaced with the CORESET pool index. [Condition 1] A CORESET pool index of 1 is set. [Condition 2] Two different values ​​of the CORESET pool index (e.g., 0 and 1) are set.

[0078] If the following condition is met, the UE may determine that it is a multi-TRP based on a single DCI. In this case, two TRPs may be interpreted as two TCI states indicated by the MAC CE / DCI. [Condition] "Enhanced TCI States Activation / Deactivation for UE-specific PDSCH MAC CE" is used to indicate one or two TCI states for one codepoint in the TCI field in the DCI.

[0079] The DCI for common beam instruction may be a UE-specific DCI format (e.g., DL DCI format (e.g., 1_1, 1_2), UL DCI format (e.g., 0_1, 0_2)), or may be a UE-group common DCI format.

[0080] Incidentally, in future wireless communication systems (e.g., Rel. 17 and later), beam management for UEs with multiple panels (multi-panels), or extension of beam management using multiple transmission / reception points (multi-Transmission / Reception Points (TRP)), are being considered.

[0081] When a terminal (UE) communicates using multiple transmission / reception points (TRPs) / UE panels, it is possible to perform beam failure detection for each TRP / UE panel. However, there has been insufficient consideration on how to control the beam failure detection (BFD) or beam failure recovery (BFR) procedures in each TRP / UE panel.

[0082] For example, in the BFR procedure, a UE that has notified information such as beam obstruction / new candidate RS performs subsequent transmission / reception processing (e.g., QCL estimation / spatial relationship estimation / UL power control) based on the response from the base station (e.g., base station response / gNB response).

[0083] [BFR for PCell / PSCell in Rel. 15] In the BFR procedure of Rel. 15, a UE transmits a PRACH when it detects a radio link failure in the PCell / PSCell. The base station response may be a response signal (e.g., PDCCH transmission) to the PRACH (e.g., PRACH for BFR) notified from the UE. The PDCCH may be transmitted using a search space set configured by higher layer signaling (e.g., recoverySearchSpaceId). The UE operation after the base station response may be PUCCH transmission / PDCCH monitoring based on a predetermined condition.

[0084] For example, when the UE receives a base station response (e.g., PDCCH), the UE may control the PUCCH to be transmitted in the same cell as the PRACH transmission and using the same spatial filter as the last PRACH transmission. Also, the transmission power of the PUCCH may be controlled based on a power control parameter (e.g., q u =0, q d =q new , l=0). These predetermined conditions (e.g., spatial filter / transmission power) may be applied from 28 symbols after the last symbol of the first received base station response (e.g., PDCCH) until the UE receives an activation command for PUCCH spatial relationship information (e.g., PUCCH-SpatialRelationInfo) or until the UE is provided with PUCCH spatial relationship information (e.g., PUCCH-SpatialRelationInfo) for PUCCH resources.

[0085] where q u may be a P0 ID for PUCCH (p0-PUCCH-Id) indicating a P0 for PUCCH (P0-PUCCH) in a P0 set for PUCCH (p0-Set).d is the RS resource index of the RS (path loss reference RS) for PUCCH path loss calculation (estimation). new , is a new candidate beam (or a new candidate beam index, a reference signal index corresponding to the new candidate beam, or a reference signal index for BFR). 1 is an index of the power control adjustment state for PUCCH (closed loop).

[0086] Furthermore, when the UE receives a base station response (for example, PDCCH), after a predetermined period, the UE monitors a predetermined index (for example, q new ) The predetermined period may be 28 symbols after the last symbol of the base station response (e.g., PDCCH) first received by the UE.

[0087] For a PCell or PSCell, if a BFR MAC CE is transmitted in Msg3 or MsgA of the contention-based random access procedure and PUCCH resources are provided with PUCCH spatial relation information (e.g., PUCCH-SpatialRelationInfo), 28 symbols after the last symbol of PDCCH reception that determines the completion of the random access procedure, the UE transmits a PUCCH on the same cell as the PRACH transmission. The PUCCH transmission uses the same spatial filter as the last PRACH transmission. The PUCCH transmission uses q u =0, q d =q new , l=0, where q new is the SS / PBCH block index selected for the last PRACH transmission.

[0088] [BFR for SCell in Rel. 16] In the BFR procedure of Rel. 16, when the radio link quality in the SCell becomes worse than a predetermined value, the UE transmits the corresponding SCell index, information about a new candidate beam (e.g., q new ) etc. into PUSCH MAC CE (for example, the first PUSCH / 1 st The base station response may be transmitted using a MAC CE (e.g., a PUSCH MAC CE). The base station response may be a response signal (e.g., a PDCCH transmission) to the MAC CE (e.g., the initial PUSCH) notified from the UE. The PDCCH may be applied to a DCI format that schedules a PUSCH transmission having the same HARQ process number as the initial PUSCH transmission and a toggled NDI field value. The UE operation after the base station response may be PUCCH transmission / PDCCH monitoring based on a predetermined condition.

[0089] For example, when the UE receives a base station response (e.g., PDCCH), it may monitor the PDCCH in all control resource sets in the SCell indicated by the MAC CE. In this case, the UE may monitor the corresponding index (e.g., q new ) may be used to monitor the PDCCH.

[0090] In addition, when the UE receives a base station response (for example, PDCCH) and satisfies a predetermined condition, the UE determines whether the q new In this case, the transmission power of the PUCCH may be controlled by a power control parameter (e.g., q u =0, q d =q new , l=0).

[0091] The predetermined condition may be, for example, at least one or all of the following: spatial relationship information for PUCCH (e.g., predetermined higher layer parameters for PUCCH (e.g., PUCCH-SpatialRelationInfo)) is provided (Condition 1); PUCCH with a Link Recovery Request (LRR) is not transmitted or is transmitted in the PCell / PSCell (Condition 2); and PUCCH SCell is included in the SCells indicated in the MAC CE (Condition 3).

[0092] As such, existing systems (e.g., Rel. 15 / Rel. 16) support the BFR procedure, but when a UE communicates using multiple TRP / UE panels, the question arises as to how to control the BFD / BFR procedure in each TRP / UE panel.

[0093] For example, after BFR completion, the PDCCH / PUCCH beam is new On the other hand, in multi-TRP BFR (e.g., M-TRP BFR), the PDSCH beam is updated to q new It is being considered whether to update it to .

[0094] For example, after receiving a response (e.g., gNB response) from the base station, the UE may determine whether the QCL estimate of the PDSCH scheduled by the PDCCH in the CORESET related to the TRP in which the beam failure occurred (e.g., failed TRP) is equal to or greater than the latest qCL estimate reported by the UE until the UE is instructed to update the TCI status from the base station (or receives an update of the TCI status). new (e.g., latest reported q new ) (Assumption #1). This assumption may also apply to SCells and SpCells (e.g., PCell / PSCell). Alternatively, this assumption may also apply to a multi-DCI case.

[0095] In Rel. 15 networks, the TCI status field is typically not present (i.e., a higher layer parameter (e.g., tciPresentInDCI) indicating the presence or absence of the TCI status field in the DCI is not configured). Therefore, the beam (or QCL assumption / TCI status) of the PDSCH may be derived from the beam (or QCL assumption / TCI status) of the PDCCH / CORESET in the following cases: - The case where the scheduling offset (e.g., scheduling offset) is smaller than a predetermined period (e.g., timeDurationForQCL) (see Figure 2A). - The case where the scheduling PDCCH does not have a TCI status field and the scheduling offset is equal to or greater than a predetermined period (e.g., timeDurationForQCL) (see Figure 2B).

[0096] Therefore, the base station may not be required to transmit MAC CE due to the TCI state of the PDSCH. new When the PDCCH beam is updated to q, the PDSCH beam derived from the PDCCH beam is also q new and if the UE receives a MAC CE for the TCI state of the PDCCH, the UE's PDCCH / PDSCH beam assumptions may both be updated.

[0097] However, if the above assumption #1 is implemented / supported, the PDSCH beam will be q new This means that the PDSCH beam is not derived from the PDCCH beam. In this case, even if the base station transmits a MAC CE (for example, a MAC CE for the TCI state of the PDCCH) to update the PDCCH beam, the PDSCH beam is not updated. new It will remain as it is.

[0098] Therefore, we define the PDSCH beam as q new The present embodiment was conceived by examining the conditions / restrictions for updating the PDSCH beam to q in all cases. new Instead of updating to q, the PDSCH beam is updated to q under certain conditions. newBy updating the PDSCH beam, it becomes possible to flexibly control the updating of the PDSCH beam.

[0099] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Each embodiment may be applied independently or in combination.

[0100] In the present disclosure, a UE may be a UE that uses multiple panels to transmit and receive data to and from a TRP, where each panel may correspond to a different TRP, one panel may correspond to multiple TRPs, or multiple panels may correspond to one TRP.

[0101] In this disclosure, a panel (or panel index) of a UE may correspond to a particular group. In this case, the UE may assume that beams / RSs of each group are measured on each panel of the UE. The UE may assume that it receives beams of multiple groups simultaneously (using different panels).

[0102] In the present disclosure, a TRP may be interchangeably referred to as a panel of TRPs (or base stations), an RS group, an antenna port group, a spatial relationship group, a QCL group, a TCI state, a TCI state group, a CORESET group, a CORESET pool, etc. Also, a TRP index may be interchangeably referred to as an RS group index, an antenna port group index, a QCL group index, a TCI state index, a TCI state group index, a CORESET group index, a CORESET pool index, etc.

[0103] In the present disclosure, when a single DCI is applied, the nth TRP (n is any integer (e.g., 1 or 2)) may correspond to the nth TCI state and the nth Code Division Multiplexing (CDM) group.

[0104] In the present 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. When multiple DCIs are applied, a CORESET pool index may be set.

[0105] In the present disclosure, a panel of a UE may be interchangeably read as an RS group, an antenna port group, a spatial relationship group, a QCL group, a TCI state group, a CORESET group, and the like.

[0106] 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, multiple panels may be associated with a group index for 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.

[0107] In the present disclosure, the serving cell / cell may be replaced with SpCell, PCell, PSCell, or SCell. In the following description, an example is given in which two TRPs correspond to a serving cell, but three or more TRPs may correspond to a serving cell.

[0108] In the present disclosure, the BFD RS in which beam failure is detected, the BFD RS in which a failure has occurred (failed), the TRP in which beam failure is detected, the TRP in which a failure has occurred (failed), the UE panel in which beam failure is detected, and the UE panel in which a failure has occurred (failed) may be read as interchangeable.

[0109] 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.

[0110] In the present disclosure, the terms "PUCCH resource" and "PUCCH spatial relationship" may be interchangeable. In the present disclosure, the terms "TRP," "TRP ID," "BFD-RS set ID," "NBI-RS set ID," and "CORESET pool index" may be interchangeable. In the present disclosure, the terms "obstacle" and "beam obstruction" may be interchangeable.

[0111] In the present disclosure, the PUCCH spatial relationship information may be interpreted as a UL TCI state, a unified UL TCI state, or a unified joint DL / UL TCI state, a spatial relationship, or a spatial domain filter. In this specification, the predetermined ID may be, for example, information used to identify a TRP (e.g., identification information related to a TRP), and may be interpreted as a TRP identification information, a TRP-ID, a group ID, or a new ID.

[0112] In the present disclosure, PUCCH, PUCCH transmission, PUCCH resource, PUCCH occasion, PUCCH spatial relationship information, and spatial relationship may be read interchangeably.

[0113] A network (e.g., a base station) may notify / configure a predetermined ID (hereinafter also referred to as TRP identification information) to a UE. For example, the base station may notify the UE of the TRP identification information using upper layer signaling (or upper layer parameters) / DCI.

[0114] The TRP identification information may be configured / defined in association with (or corresponding to) the PUCCH spatial related information. When multiple PUCCH spatial related information is configured in a UE, each PUCCH spatial related information may be associated with a respective predetermined TRP identification information.

[0115] In the following explanation, the BFR procedure will be described as an example in which one or more transmission and reception points are used, but this embodiment can also be applied to communication control other than the BFR procedure.

[0116] (First Aspect) In the first aspect, after BFR is completed, the PDSCH beam is adjusted to a predetermined value (for example, q new) will be explained. new To update the PDSCH reception to q new After the BFR is completed, the control may be interpreted as after a response is received from the base station.

[0117] The UE determines the PDSCH beam control (e.g., q) after the BFR is completed based on at least one of the type of cell where the beam failure recovery was performed and the applied beam failure reporting mechanism. new For example, the UE may determine whether to update the PDSCH beam to q after BFR completion for at least one of the following options 1-1 to 1-4. new may be updated to.

[0118] <Option 1-1> For BFR for SpCell based on CBRA (collision-based) / CFRA (non-collision-based), after BFR is completed, the PDSCH beam is new The CBRA (collision-based) / CFRA (non-collision-based) based BFR for the SpCell may be the CBRA (collision-based) / CFRA (non-collision-based) based BFR using the PRACH in Rel. 15.

[0119] For example, after receiving a response (e.g., gNB response) from the base station, the UE may report that the QCL estimate of the PDSCH scheduled by the PDCCH in the CORESET associated with the SpCell in which the beam failure occurred or the TRP of the SpCell is the same as the latest qCL estimate reported until the UE is instructed to update the TCI status by the base station. new (e.g., latest reported q new )

[0120] <Option 1-2> For CBRA-based BFR for SpCell, after BFR is completed, the PDSCH beam is newThe CBRA-based BFR for the SpCell may be BFR using the CBRA-based PRACH of Rel. 16. The BFR MAC CE may include Message 3 / Message A of the CBRA BFR.

[0121] For example, after receiving a response (e.g., gNB response) from the base station, the UE may report that the QCL estimate of the PDSCH scheduled by the PDCCH in the CORESET associated with the SpCell in which the beam failure occurred or the TRP of the SpCell is the same as the latest qCL estimate reported until the UE is instructed to update the TCI status by the base station. new (e.g., latest reported q new )

[0122] <Option 1-3> For BFR MAC CE-based BFR for SCell, after BFR is completed, the PDSCH beam is new The BFR for the BFR MAC CE-based SCell may be BFR using the BFR MAC CE of Rel. 16.

[0123] For example, after receiving a response (e.g., gNB response) from the base station, the UE may update the TCI status until the base station instructs the UE to update the TCI status. The QCL estimate of the PDSCH scheduled by the PDCCH in the CORESET associated with the SCell or the TRP of the SCell where the beam failure occurred is the same as the latest qCL estimate reported. new (e.g., latest reported q new )

[0124] <Option 1-4> For TRP-specific BFR for PCell / SCell, after BFR completion, PDSCH beam is newThe TRP-specific BFR for the PCell / SCell may be the TRP-specific BFR for the PCell / SCell in Rel. 17. The TRP may be a multi-DCI (e.g., M-DCI) based M-TRP or a single-DCI (e.g., S-DCI) based M-TRP. In addition, the BFR MAC CE may be used in the BFR report.

[0125] For example, after receiving a response (e.g., gNB response) from the base station, the UE may, until the base station instructs the UE to update the TCI status, assume that the QCL estimate of the PDSCH scheduled by the PCell / SCell in which the beam failure occurred or the PDCCH in the CORESET related to the TRP of the PCell / SCell is the latest q new (e.g., latest reported q new )

[0126] (Second Aspect) In the second aspect, after BFR is completed, the PDSCH beam is adjusted to a predetermined value (for example, q new ) (or conditions / cases under which updating to a predetermined value is restricted). Note that at least one of Option 1-1 to Option 1-4 of the first aspect and at least one of Option 2-1 to Option 2-5 of the second aspect may be applied in combination.

[0127] After BFR is completed, the PDSCH beam is new The condition / case for updating may be applied only when a predetermined condition / case (for example, at least one of the following options 2-1 to 2-5) is met.

[0128] <Option 2-1> If the TCI status field is set to be included in the DCI, the UE will select the PDSCH beam as q after the BFR is completed. new The TCI status field may be set to be included in the DCI when a predetermined higher layer parameter (e.g., tci-PresentInDCI) is set / enabled / activated.

[0129] For example, after BFR completion, the UE may only receive q if the TCI status field is present in the DCI (e.g., the DCI scheduling the PDSCH) (i.e., tci-PresentInDCI is set). new may be used to control reception of the PDSCH.

[0130] This allows the reuse of the mechanism of the existing system, in which the PDSCH beam is always derived from the PDCCH beam when the TCI status field is not present. On the other hand, when the TCI status field is present, after the BFR is completed, the q new can be used for the PDSCH. In this case, the base station may transmit a MAC CE for the TCI state of the PDSCH.

[0131] <Option 2-2> After BFR is completed, if PDSCH is scheduled by a DCI format in which the TCI status field does not exist, the UE new (see FIG. 3B).

[0132] <Option 2-3> If the scheduling offset between the PDSCH and the PDCCH (or DCI / CORESET) that schedules the PDSCH is equal to or greater than a predetermined period (for example, timeDurationForQCL), the UE schedules the PDSCH beam as q new For example, after BFR is completed, if the scheduling offset between the PDSCH and the PDCCH that schedules the PDSCH is ≥ timeDurationForQCL, the UE may update the PDSCH to q new The signal may be received based on the

[0133] <Option 2-4> If the scheduling offset between the PDSCH and the PDCCH (or DCI / CORESET) that schedules the PDSCH is less than / equal to a predetermined period (e.g., timeDurationForQCL), the UE allocates the PDSCH beam to q newFor example, after BFR is completed, if the scheduling offset between the PDSCH and the PDCCH that schedules the PDSCH is less than timeDurationForQCL, the UE may update the PDSCH to q new The signal may be received based on the

[0134] <Option 2-5> When at least one of multi-DCI-based multi-TRP (see, for example, FIG. 5A), single-DCI-based multi-TRP (see, for example, FIG. 5B), and single-TRP is applied, the UE may select a PDSCH beam from q new may be updated to.

[0135] In at least one of Option 2-1 to Option 2-5, q corresponding to PDSCH new may be maintained until the UE is instructed by the base station to update the TCI state of the PDCCH / PDSCH (or until it receives an update of the TCI state of the PDCCH / PDSCH). new It may have the same CORESET pool index / BFD-RS set / TRP as the updated PDSCH.

[0136] In the second aspect, the PDSCH beam is q new The conditions / cases for updating may be applied when at least two of Option 2-1 to Option 2-5 are satisfied. Combinations of at least two of Option 2-1 to Option 2-5 may be, for example, Option 2-1 and Option 2-3, Option 2-1 and Option 2-4, Option 2-1 and Option 2-5, Option 2-1, Option 2-3 and Option 2-5, or Option 2-1, Option 2-4 and Option 2-5. Of course, the combinations of options are not limited to these.

[0137] <Modifications> The above-described assumption #1 may be replaced with at least one of the following assumptions #2 and #3 and applied to the first aspect / second aspect.

[0138] For example, after receiving a response (e.g., gNB response) from the base station, if tciPresentInDCI is set, the UE may, until it receives an instruction to update the TCI status from the base station (or receives an update of the TCI status), assume that the QCL assumption of the PDSCH scheduled by the PDCCH in the CORESET related to the TRP in which the beam failure occurred (e.g., failed TRP) is the latest q new (e.g., latest reported q new ) (Assumption #2). This assumption may also apply to SCells and SpCells (e.g., PCell / PSCell). Alternatively, this assumption may also apply to a multi-DCI case.

[0139] For example, assume that after the UE receives a response (e.g., a gNB response) from the base station, tciPresentInDCI is configured, and the time offset between the reception of the DL DCI and the PDSCH (e.g., PDSCH associated with the CORESET pool index) of the corresponding serving cell is equal to or greater than a predetermined threshold (e.g., timeDurationForQCL). In this case, the UE will not update the QCL of the PDSCH scheduled by the PDCCH in the CORESET associated with the TRP in which the beam failure occurred (e.g., failed TRP) until the UE is instructed by the base station to update the TCI status of the PDSCH (e.g., PDSCH associated with the same CORESET pool index) (or receives an update of the TCI status). new (e.g., latest reported q new ) (Assumption #3). This assumption may also apply to SCells and SpCells (e.g., PCell / PSCell). Alternatively, this assumption may also apply to a multi-DCI case.

[0140] The PDSCH in the first aspect / second aspect may be a PDSCH configured with a Rel. 15 / 16 TCI state, or may be a PDSCH configured with a Rel. 17 TCI state (e.g., unified TCI state / joint TCI state, or separate TCI state / DL TCI state).

[0141] (Wireless Communication System) The configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above embodiments of the present disclosure or a combination thereof.

[0142] 6 is a diagram illustrating an example of a 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) or 5th generation mobile communication system New Radio (5G NR) specified by the Third Generation Partnership Project (3GPP).

[0143] The wireless communication system 1 may also support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). 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)), etc.

[0144] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (Master Node (MN)), and the NR base station (gNB) is the secondary node (Secondary Node (SN)). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0145] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity in which both the MN and SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0146] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with a relatively wide coverage, and base stations 12 (12a-12c) that are located within the macrocell C1 and form small cells C2 that are smaller than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The locations and numbers of the cells and user terminals 20 are not limited to the embodiment shown in the figure. Hereinafter, when there is no need to distinguish between the base stations 11 and 12, they will be collectively referred to as base station 10.

[0147] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CCs) and dual connectivity (DC).

[0148] 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 and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a higher frequency band than FR2.

[0149] Furthermore, the user terminal 20 may perform communication using at least one of time division duplex (TDD) and frequency division duplex (FDD) in each CC.

[0150] The multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with the 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 the base stations 11 and 12, the base station 11 corresponding to the upper 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.

[0151] The base station 10 may be connected to the core network 30 directly or via another base station 10. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), and the like.

[0152] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0153] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the wireless communication system 1. For example, 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), or the like may be used in at least one of the downlink (DL) and uplink (UL).

[0154] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (e.g., other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0155] In the wireless communication system 1, a downlink shared channel (Physical Downlink Shared Channel (PDSCH)) shared by each user terminal 20, a broadcast channel (Physical Broadcast Channel (PBCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), etc. may be used as the downlink channel.

[0156] Furthermore, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), or the like may be used as an uplink channel.

[0157] The PDSCH transmits user data, higher layer control information, a System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit a Master Information Block (MIB).

[0158] 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 for at least one of the PDSCH and the PUSCH.

[0159] Note that the DCI for scheduling the PDSCH may be referred to as a DL assignment, a DL DCI, etc., and the DCI for scheduling the PUSCH may be referred to as a UL grant, a UL DCI, etc. Note that the PDSCH may be replaced with DL data, and the PUSCH may be replaced with UL data.

[0160] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources for searching for DCI. The search space corresponds to a search region and a 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.

[0161] 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 terms "search space," "search space set," "search space configuration," "search space set configuration," "CORESET," "CORESET configuration," and the like in the present disclosure may be read interchangeably.

[0162] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), delivery confirmation information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0163] In the present disclosure, downlink, uplink, etc. may be expressed without adding "link." Also, various channels may be expressed without adding "Physical" to the beginning.

[0164] In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, as the DL-RS, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted.

[0165] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including an SS (PSS, SSS) and a PBCH (and a DMRS for the PBCH) may be referred to as an SS / PBCH block, an SS Block (SSB), or the like. Note that the SS, SSB, and the like may also be referred to as a reference signal.

[0166] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), or the like may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may also be called a user equipment-specific reference signal (UE-specific reference signal).

[0167] 7 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 transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that the base station may include one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140.

[0168] In this example, the functional blocks of the characteristic parts of 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 processing of each unit described below may be omitted.

[0169] The control unit 110 performs overall control of the base station 10. The control unit 110 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0170] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurement, etc. The control unit 110 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 120. The control unit 110 may perform call processing (setting up, releasing, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0171] The transceiver 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 transceiver unit 120 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0172] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or may be configured from a transmitting unit and a receiving unit. The transmitting unit may be configured from a transmission processing unit 1211 and an RF unit 122. The receiving unit may be configured from a reception processing unit 1212, the RF unit 122, and a measurement unit 123.

[0173] The transmitting and receiving antenna 130 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0174] The transceiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 120 may receive the above-mentioned uplink channel, uplink reference signal, etc.

[0175] The transceiver 120 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0176] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0177] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0178] The transceiver unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 130.

[0179] On the other hand, the transceiver unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 130.

[0180] The transceiver 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 to the acquired baseband signal, thereby acquiring user data, etc.

[0181] The transceiver 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.

[0182] The transmission path interface 140 may transmit and receive signals (backhaul signaling) between 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.

[0183] The transmitting section and receiving section of the base station 10 in the present disclosure may be configured by at least one of the transmitting / receiving section 120, the transmitting / receiving antenna 130, and the transmission path interface 140.

[0184] The transceiver 120 may receive information about new candidate beams in beam failure recovery. The transceiver 120 may transmit a downlink shared channel based on a pseudo-co-location assumption.

[0185] After beam failure recovery is completed, the control unit 110 may decide to apply (or whether to apply) a new candidate beam as a quasi-colocation assumption corresponding to the downlink shared channel based on whether or not a specified condition is met.

[0186] (User Terminal) Fig. 8 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0187] In this example, the functional blocks of the characteristic parts of 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. Some of the processing of each unit described below may be omitted.

[0188] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured from a controller, a control circuit, etc., which are described based on common understanding in the technical field to which the present disclosure relates.

[0189] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may control transmission and reception, measurement, etc. using the transceiver unit 220 and the transceiver antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals and transfer them to the transceiver unit 220.

[0190] The transceiver 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 transceiver unit 220 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0191] The transmitting / receiving unit 220 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiving unit may be composed of a reception processing unit 2212, an RF unit 222, and a measurement unit 223.

[0192] The transmitting / receiving antenna 230 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0193] The transceiver 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 220 may transmit the above-mentioned uplink channel, uplink reference signal, etc.

[0194] The transceiver unit 220 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0195] The transceiver unit 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

[0196] The transmitter / receiver 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, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0197] Whether or not to apply DFT processing may be based on the setting of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the transmission processing to transmit the channel using a DFT-s-OFDM waveform, and if not, it may not be necessary to perform DFT processing as the transmission processing.

[0198] The transceiver unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 230.

[0199] On the other hand, the transceiver unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 230.

[0200] The transceiver unit 220 (reception processing unit 2212) may apply reception processing such as analog-to-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.

[0201] The transceiver 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), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

[0202] The transmitting unit and receiving unit of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving unit 220 and the transmitting / receiving antenna 230.

[0203] The transceiver 220 may report (or transmit) information about new candidate beams in beam failure recovery. The transceiver 220 may receive a downlink shared channel based on a quasi-co-location assumption.

[0204] After beam failure recovery is completed, the control unit 210 may decide to apply (or whether to apply) a new candidate beam as a quasi-colocation assumption corresponding to the downlink shared channel based on whether or not a specified condition is met.

[0205] The predetermined condition may be at least one of a type of cell in which beam failure recovery has been performed and an applied beam failure reporting mechanism, or the predetermined condition may be whether a transmission configuration indicator (TCI) status field is set, or the predetermined condition may be a scheduling offset between a downlink shared channel and a downlink control channel that schedules the downlink shared channel.

[0206] (Hardware Configuration) Note that the block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may be realized by combining software with the single device or the multiple devices.

[0207] Here, the functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission may be called a transmitting unit, transmitter, etc. As described above, the implementation method of each is not particularly limited.

[0208] For example, a base station, a user terminal, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 9 is a diagram illustrating 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 be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0209] In the present disclosure, the terms apparatus, circuit, device, section, unit, etc. may be used interchangeably. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0210] For example, although only one processor 1001 is shown, there may be multiple processors. Furthermore, processing may be performed by one processor, or processing may be performed by two or more processors simultaneously, serially, or in other ways. Furthermore, processor 1001 may be implemented by one or more chips.

[0211] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading specified software (programs) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, control communication via the communication device 1004, and control at least one of reading and writing data in the memory 1002 and the storage 1003.

[0212] The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transceiver unit 120 (220), etc. may be realized by the processor 1001.

[0213] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 110 (210) may be implemented by a control program stored in the memory 1002 and running on the processor 1001, and the other functional blocks may be implemented in a similar manner.

[0214] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EEPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, cache, main memory, etc. The memory 1002 may store executable programs (program codes), software modules, etc. for implementing a wireless communication method according to an embodiment of the present disclosure.

[0215] Storage 1003 is a computer-readable recording medium and may be composed of at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray 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, or other suitable storage medium. Storage 1003 may also be referred to as an auxiliary storage device.

[0216] The communication device 1004 is hardware (transmission / reception device) for communicating 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, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmission / reception unit 120 (220), transmission / reception antenna 130 (230), etc. may be realized by the communication device 1004. The transmission / reception unit 120 (220) may be implemented as a transmission unit 120a (220a) and a reception unit 120b (220b) that are physically or logically separated.

[0217] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0218] Furthermore, 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 between each device.

[0219] Furthermore, 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), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized using this hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0220] (Modifications) Note that terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0221] A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0222] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and may indicate at least one of, for example, Subcarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, Transmission Time Interval (TTI), number of symbols per TTI, radio frame structure, specific filtering performed by a transceiver in the frequency domain, and specific windowing performed by a transceiver in the time domain.

[0223] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol) in the time domain. A slot may also be a time unit based on numerology.

[0224] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (PUSCH) mapping type B.

[0225] A radio frame, a subframe, a slot, a minislot, and a symbol all represent time units for transmitting signals. The radio frame, the subframe, the slot, the minislot, and the symbol may be referred to by other names corresponding to the radio frame, the subframe, the slot, the minislot, and the symbol. Note that the time units such as a frame, a subframe, a slot, a minislot, and a symbol in the present disclosure may be interchangeable.

[0226] For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, 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, minislot, etc. instead of a subframe.

[0227] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. Note that the definition of TTI is not limited to this.

[0228] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0229] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0230] A TTI having a time length of 1 ms may be called a regular TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0231] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and greater than or equal to 1 ms.

[0232] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may be determined based on numerology.

[0233] In addition, an RB may include one or more symbols in the time domain and may have a length of one slot, one minislot, one subframe, or one TTI, each of which may be composed of one or more resource blocks.

[0234] In addition, one or more RBs may be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0235] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0236] A Bandwidth Part (BWP), which may also be referred to as a partial bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a Common Reference Point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0237] The BWP may include a UL BWP (BWP for UL) and a DL BWP (BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0238] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0239] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. 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, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0240] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by a predetermined index.

[0241] The names used for parameters and the like in this disclosure are not intended to be limiting in any way. Furthermore, the mathematical expressions and the like using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0242] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0243] Furthermore, information, signals, etc. may be output from a higher layer to a lower layer and / or from a lower layer to a higher layer. Information, signals, etc. may be input / output via multiple network nodes.

[0244] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0245] 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) and Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB) and System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0246] Note that the physical layer signaling may be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. Furthermore, the RRC signaling may be referred to as an RRC message, such as an RRC Connection Setup message or an RRC Connection Reconfiguration message. Furthermore, the MAC signaling may be notified using, for example, a MAC Control Element (CE).

[0247] Furthermore, notification of specified information (e.g., notification that "it is X") is not limited to explicit notification, but may be made implicitly (e.g., by not notifying the specified information or by notifying other information).

[0248] The determination may be made by a value represented by one bit (0 or 1), by a Boolean value represented by true or false, or by a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0249] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0250] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), these wired and / or wireless technologies are included within the definition of transmission media.

[0251] As used in this disclosure, the terms "system" and "network" may be used interchangeably. A "network" may refer to devices included in the network (e.g., base stations).

[0252] 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," "transmit power," "phase rotation," "antenna port," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," etc. may be used interchangeably.

[0253] 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," etc. may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0254] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be partitioned into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication service within that coverage.

[0255] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0256] A mobile station may also be referred to as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0257] At least one of the base station and the mobile station may be called a transmitting device, a receiving 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 object, the moving object itself, etc.

[0258] The mobile body is a movable object that can move at any speed and naturally includes cases where the mobile body is stationary. Examples of the mobile body include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcars, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and objects mounted thereon. The mobile body may also be a mobile body that moves autonomously based on an operation command.

[0259] The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Note that at least one of the base station and the mobile station may also include devices that do 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.

[0260] 10 is a diagram showing an example of a vehicle according to an embodiment. The vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, an electronic control unit 49, various sensors (including a current sensor 50, an RPM sensor 51, an air pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

[0261] The drive unit 41 is configured with at least one of an engine, a motor, and a hybrid of an engine and a motor, for example. The steering unit 42 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by a user.

[0262] The electronic control unit 49 is composed of a microprocessor 61, memory (ROM, RAM) 62, and a communication port (for example, an input / output (IO) port) 63. Signals are input to the electronic control unit 49 from various sensors 50-58 provided in the vehicle. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

[0263] The signals from the various sensors 50-58 include a current signal from a current sensor 50 that senses the current of the motor, a rotation speed signal of the front wheels 46 / rear wheels 47 obtained by a rotation speed sensor 51, an air pressure signal of the front wheels 46 / rear wheels 47 obtained by an air pressure sensor 52, a vehicle speed signal obtained by a vehicle speed sensor 53, an acceleration signal obtained by an acceleration sensor 54, a depression amount signal of the accelerator pedal 43 obtained by an accelerator pedal sensor 55, a depression amount signal of the brake pedal 44 obtained by a brake pedal sensor 56, an operation signal of the shift lever 45 obtained by a shift lever sensor 57, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 58.

[0264] The information service unit 59 is composed of various devices, such as a car navigation system, an audio system, speakers, a display, a television, and a radio, for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 59 uses information acquired from external devices via the communication module 60 or the like to provide various information / services (e.g., multimedia information / multimedia services) to the occupants of the vehicle 40.

[0265] The information service unit 59 may include input devices (e.g., keyboards, mice, microphones, switches, buttons, sensors, touch panels, etc.) that accept input from the outside, and may also include output devices (e.g., displays, speakers, LED lamps, touch panels, etc.) that output to the outside.

[0266] The driving assistance system unit 64 includes various devices for providing functions to prevent accidents and reduce the driver's driving burden, such as millimeter-wave radar, Light Detection and Ranging (LiDAR), cameras, positioning locators (e.g., Global Navigation Satellite System (GNSS)), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyro systems (e.g., Inertial Measurement Units (IMUs), Inertial Navigation Systems (INSs)), artificial intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driving assistance functions or autonomous driving functions.

[0267] The communication module 60 can communicate with the microprocessor 61 and components of the vehicle 40 via the communication port 63. For example, the communication module 60 transmits and receives data (information) via the communication port 63 to and from the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and the various sensors 50-58, which are provided in the vehicle 40.

[0268] The communication module 60 is a communication device that can be controlled by the microprocessor 61 of the electronic control unit 49 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 60 may be located either inside or outside the electronic control unit 49. The external device may be, for example, the base station 10 or the user terminal 20 described above. Furthermore, the communication module 60 may be, for example, at least one of the base station 10 and the user terminal 20 described above (or may function as at least one of the base station 10 and the user terminal 20).

[0269] The communication module 60 may transmit at least one of signals from the above-mentioned various sensors 50-58 input to the electronic control unit 49, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 59 to an external device via wireless communication. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 60 may include information based on the above-mentioned input.

[0270] The communication module 60 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from an external device and displays it on an information service unit 59 provided in the vehicle. The information service unit 59 may also be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH received by the communication module 60 (or data / information decoded from the PDSCH)).

[0271] Furthermore, the communication module 60 stores various information received from external devices in a memory 62 that can be used by the microprocessor 61. Based on the information stored in the memory 62, the microprocessor 61 may control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, various sensors 50-58, and the like provided in the vehicle 40.

[0272] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, terms such as an uplink channel and a downlink channel may be read as a sidelink channel.

[0273] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station 10 may be configured to have the functions of the user terminal 20 described above.

[0274] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc.), or a combination thereof.

[0275] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0276] Each aspect / embodiment described in the present disclosure may be a technology other than 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 decimal number)), 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 802.17 (WiMAX (registered trademark)), IEEE 802.19 (WiMAX (registered trademark)), IEEE 802.20 (WiMAX (registered trademark)), IEEE 802.21 (Wi-Fi (registered trademark)), IEEE 802.22 (WiMAX (registered trademark)), IEEE 802.23 (WiMAX (registered trademark)), IEEE 802.24 (WiMAX (registered trademark)), IEEE 802.25 (WiMAX (registered trademark)), IEEE 802.26 (WiMAX (registered trademark)), IEEE 802.27 (WiMAX (registered trademark)), IEEE 802.28 (WiMAX (registered trademark)), IEEE 802.29 (WiMAX (registered trademark)), IEEE 802.30 (WiMAX (registered trademark)), IEEE 802.31 (Wi-Fi (registered trademark)), IEEE 802.32 (WiMAX (registered trademark)), IEEE 802.33 (WiMAX (registered trademark)), IEEE 802. The present invention may be applied to systems that use IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other suitable wireless communication methods, or to next-generation systems that are expanded, modified, created, or defined based on these. Furthermore, the present invention may be applied to a combination of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0277] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0278] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0279] The term "determining" as used in this disclosure may encompass a wide variety of actions. For example, "determining" may be considered to be judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., looking up in a table, database, or another data structure), ascertaining, etc.

[0280] Additionally, "determining" may be considered to be "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), etc.

[0281] Also, "determination" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. In other words, "determination" may be considered to be "deciding" some action.

[0282] Furthermore, "judgment (decision)" may be read as "assuming," "expecting," "considering," or the like.

[0283] The "maximum transmit power" in this disclosure may mean the maximum value of transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

[0284] As used in this disclosure, the terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access."

[0285] In this disclosure, when two elements are connected, they may be considered to be "connected" or "coupled" to one another using one or more wires, cables, printed electrical connections, etc., as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, etc., as some non-limiting and non-exhaustive examples.

[0286] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0287] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0288] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0289] Although the invention according to the present disclosure has been described in detail above, it is clear 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 in modified and altered forms without departing from the spirit and scope of the invention as defined by the description of the claims. Therefore, the description of the present disclosure is intended to be illustrative and explanatory and does not impose any limiting meaning on the invention according to the present disclosure.

[0290] This application is based on Japanese Patent Application No. 2021-188380, filed on November 19, 2021, the contents of which are incorporated herein in their entirety.

Claims

1. A receiver that receives a setting regarding a unified transmission configuration indication (TCI) state and a downlink control channel (PDCCH) indicating completion of beam failure recovery (BFR), A terminal having a control unit that, when the unified TCI state is set for a downlink shared channel (PDSCH), controls reception of the PDSCH by applying a new candidate beam as a quasi-colocation assumption corresponding to the PDSCH after the BFR is completed.

2. The terminal described in claim 1, wherein the BFR is a BFR for a collision-based (CBRA)-based serving cell (PSCell).

3. The terminal described in claim 1, wherein the BFR is a BFR MAC control element (CE)-based BFR for an SCell.

4. receiving a configuration regarding a unified transmission configuration indication (TCI) state and a downlink control channel (PDCCH) indicating completion of beam failure recovery (BFR); A wireless communication method for a terminal, comprising: when the unified TCI state is set for a downlink shared channel (PDSCH), after the BFR is completed, a step of applying a new candidate beam as a quasi-co-location assumption corresponding to the PDSCH to control reception of the PDSCH.

5. A transmitter that transmits a configuration regarding a unified transmission configuration indication (TCI) state and a downlink control channel (PDCCH) indicating completion of beam failure recovery (BFR); A base station having a control unit that, when the unified TCI state is set for a downlink shared channel (PDSCH), controls the transmission of the PDSCH by applying a new candidate beam as a quasi-colocation assumption corresponding to the PDSCH after the BFR is completed.

6. A system having a terminal and a base station, The terminal a receiver for receiving a downlink control channel (PDCCH) indicating a configuration regarding a unified transmission configuration indication (TCI) state and a completion of beam failure recovery (BFR); and a control unit that, when the unified TCI state is set for a downlink shared channel (PDSCH), controls reception of the PDSCH by applying a new candidate beam as a quasi-co-location assumption corresponding to the PDSCH after the BFR is completed, The base station A system comprising a transmitter that transmits the PDCCH.