Terminal, wireless communication method, and base station

Abstract

A terminal according to one embodiment of the present disclosure includes: a reception unit that receives a first configuration of a control resource set (CORESET) having a plurality of transmission configuration indication (TCI) states, receives a second configuration of one or more first reference signals for beam failure detection (BFD) or radio link monitoring (RLM), and receives a medium access control-control element (MAC CE); and a control unit that determines one or more second reference signals to be used in the BFD or the RLM based on the first configuration, the second configuration, and the MAC CE, the one or more first reference signals being associated with the plurality of TCI states, respectively. According to one embodiment of the present disclosure, a BFD RS can be appropriately determined.

Description

Technical Field

[0001] This disclosure relates to terminals, wireless communication methods, and base stations in next-generation mobile communication systems. Background Technology

[0002] In Universal Mobile Telecommunications System (UMTS) networks, Long Term Evolution (LTE) was standardized with the aim of achieving higher data rates and lower latency (Non-Patent Document 1). Furthermore, LTE-Advanced (3GPP Rel. 10-14) was standardized with the aim of further increasing capacity and improving the height of LTE (Third Generation Partnership Project (3GPP) Release (Rel.) 8, 9).

[0003] The development of successor systems to LTE is also underway (e.g., also known as the 5th generation mobile communication system (5G), 5G+, the 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel.15 and later, etc.).

[0004] Existing technical documents

[0005] Non-patent literature

[0006] Non-patent document 1: 3GPP TS 36.300V8.12.0 "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)", April 2010 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In NR, a process is being studied for user terminals (user terminals, user equipment) to detect beam failure (Beam Failure Detection: BFD) and switch to other beams (also known as Beam Failure Recovery (BFR) process, BFR, etc.).

[0009] However, the method for determining the BFD reference signal (RS) is not yet clear. Failure to properly determine the BFD RS could lead to reduced throughput or degraded communication quality.

[0010] Therefore, one of the purposes of this disclosure is to provide a suitable terminal, wireless communication method, and base station for detecting beam failure.

[0011] Methods for solving problems

[0012] One aspect of this disclosure relates to a terminal comprising: a receiving unit that receives a first setting of a control resource set (CORESET) having a plurality of transmit setting indication states (TCI) states, and a second setting of one or more first reference signals for beam failure detection (BFD) or radio link monitoring (RLM), and a media access control-control element (MACCE); and a control unit that, based on the first setting, the second setting, and the MACCE, determines one or more second reference signals to be used in the BFD or the RLM, wherein the one or more first reference signals are respectively associated with the plurality of TCI states.

[0013] The effects of the invention

[0014] According to one method of this disclosure, BFD RS can be appropriately determined. Attached Figure Description

[0015] Figure 1 This is a diagram illustrating an example of the beam recovery process.

[0016] Figure 2 This is a diagram illustrating an example of the BFD-RS settings for each cell.

[0017] Figure 3 This is another example of the BFD-RS settings for each cell.

[0018] Figure 4 This is a diagram representing an example of the BFD-RS settings for each TRP.

[0019] Figure 5This is another example of the BFD-RS setting for each TRP.

[0020] Figure 6A as well as Figure 6B This is a diagram illustrating an example of the MAC CE involved in the second embodiment.

[0021] Figure 7 This is a diagram illustrating an example of a MAC CE involved in a variation of the second embodiment.

[0022] Figure 8 This is a diagram illustrating an example of the schematic structure of a wireless communication system according to one embodiment.

[0023] Figure 9 This is a diagram illustrating an example of the structure of a base station according to one embodiment.

[0024] Figure 10 This is a diagram illustrating an example of the structure of a user terminal according to one embodiment.

[0025] Figure 11 This is a diagram illustrating an example of the hardware structure of a base station and a user terminal according to one embodiment. Detailed Implementation

[0026] (TCI, Spatial Relations, QCL)

[0027] In NR, research is underway on controlling the reception processing (e.g., at least one of receiving, demapping, demodulation, and decoding) and transmission processing (e.g., at least one of transmitting, mapping, precoding, modulation, and encoding) of at least one of the signals and channels (referred to as signal / channel) in the UE based on the Transmission Configuration Indication state (TCI state).

[0028] TCI states can also represent information about signals / channels applied to the downlink. The equivalent of TCI states applied to signals / channels in the uplink can also be described as spatial relations.

[0029] TCI status refers to information related to quasi-co-location (QCL) of a signal / channel, and can also be referred to as spatial reception parameters, spatial relation information, etc. TCI status can also be set for the UE on a per-channel or per-signal basis.

[0030] QCL refers to an indicator representing the statistical properties of a signal / channel. For example, it can also mean that, given a QCL relationship between a signal / channel and other signals / channels, it can be assumed that at least one of the following is the same (QCL): Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (e.g., spatial Rxparameter) among these different signals / channels.

[0031] Additionally, the spatial reception parameters may also correspond to the UE's receive beam (e.g., receive analog beam), and the beam may also be determined based on the spatial QCL. The QCL (or at least one element of the QCL) in this disclosure may also be rewritten as sQCL (spatial QCL).

[0032] Regarding QCL, multiple types (QCL types) can also be specified. For example, four QCL types, i.e., type AD, can be set. In these four QCL types AD, the parameters (or sets of parameters) that can be assumed to be the same are different. The parameter (also called the QCL parameter) is represented as follows:

[0033] • QCL Type A (QCL-A): Doppler shift, Doppler spread, average delay, and delay spread.

[0034] • QCL Type B (QCL-B): Doppler shift and Doppler extension.

[0035] • QCL Type C (QCL-C): Doppler shift and average delay,

[0036] • QCL type D (QCL-D): Space reception parameters.

[0037] The scenario in which a UE envisions a certain Control Resource Set (CORESET), channel, or reference signal in a specific QCL (e.g., QCL type D) relationship with other CORESETs, channels, or reference signals can also be referred to as a QCL assumption.

[0038] The UE may also determine at least one of the transmit beam (Tx beam) and receive beam (Rx beam) of the signal / channel based on the TCI state or QCL assumption of the signal / channel.

[0039] The TCI state can also be, for example, information related to the QCL between the target channel (in other words, the reference signal (RS) used by the channel) and other signals (e.g., other RSs). The TCI state can also be set (indicated) by higher-layer signaling, physical-layer signaling, or a combination thereof.

[0040] Physical layer signaling can also be, for example, downlink control information (Downlink Control Information (DCI)).

[0041] The channel that is set (specified) to TCI state or spatial relationship can be, for example, at least one of the following: downlink shared channel (Physical Downlink Shared Channel (PDSCH))), downlink control channel (Physical Downlink Control Channel (PDCCH))), uplink shared channel (Physical Uplink Shared Channel (PUSCH))), and uplink control channel (Physical Uplink Control Channel (PUCCH))).

[0042] Furthermore, the RS that is related to the channel as QCL can be at least one of the following: a Synchronization Signal Block (SSB), a Channel State Information Reference Signal (CSI-RS), a Measurement Reference Signal (Sounding Reference Signal (SRS)), a Tracking CSI-RS (also known as a Tracking Reference Signal (TRS)), or a QCL Detection Reference Signal (also known as a QRS).

[0043] An SSB is a block of signals that contains at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a broadcast channel (Physical Broadcast Channel (PBCH)). An SSB can also be referred to as an SS / PBCH block.

[0044] The RS of QCL type X in TCI state can also refer to the RS that is in a QCL type X relationship with a certain channel / signal (DMRS), and this RS can also be called the QCL source of QCL type X in TCI state.

[0045] Alternatively, QCL type ARS can always be set for PDCCH and PDSCH, while QCL type DRS can be additionally set. It is difficult to estimate Doppler offset, delay, etc., through the reception of a single transmission (one-shot) of DMRS; therefore, QCL type ARS is used to improve channel estimation accuracy. QCL type DRS is used for determining the receive beam during DMRS reception.

[0046] For example, TRS1-1, 1-2, 1-3, and 1-4 are transmitted, and TRS1-1 is notified as a QCL type C / D RS via the PDSCH TCI state. By being notified of the TCI state, the UE can utilize information obtained from the results of past periodic TRS1-1 reception / measurement for PDSCH reception / channel estimation using DMRS. In this case, the QCL source of PDSCH is TRS1-1, and the QCL target is PDSCH using DMRS.

[0047] (Multiple TRPs)

[0048] In NR, research is underway on using one or more Transmission / Reception Points (TRPs) (multi-TRPs (MTRPs)) with one or more panels (multi-panel) to perform DL (delivery-to-depth) transmissions to the UE. Additionally, research is underway on the UE using one or more panels to perform UL (ultimate-range) transmissions to one or more TRPs.

[0049] In addition, multiple TRPs can correspond to the same cell identifier (cell Identifier(ID)) or different cell IDs. The cell ID can be a physical cell ID or a virtual cell ID.

[0050] Multiple TRPs (e.g., TRP #1, #2) can also be connected via ideal / non-ideal backhaul, and information, data, etc., can be exchanged. Different codewords (CWs) and different layers can also be sent from each TRP within a multi-TRP network. As a method of multi-TRP transmission, non-coherent joint transmission (NCJT) can also be used.

[0051] In NCJT, for example, TRP#1 modulates and maps the first codeword, performs layer mapping, and transmits the first PDSCH using the first precoding and through a first number of layers (e.g., 2 layers). Furthermore, TRP#2 modulates and maps the second codeword, performs layer mapping, and transmits the second PDSCH using the second precoding and through a second number of layers (e.g., 2 layers).

[0052] Furthermore, multiple PDSCHs undergoing NCJT (multiple PDSCHs) can be defined as partially or completely overlapping in terms of at least one of the time and frequency domains. In other words, at least one of the time and frequency resources of the first PDSCH from the first TRP and the second PDSCH from the second TRP can also overlap.

[0053] It can also be conceivable that these first and second PDSCHs are not quasi-co-located (QCL). The reception of multiple PDSCHs can also be rewritten as the simultaneous reception of PDSCHs that are not of a certain QCL type (e.g., QCL type D).

[0054] Multiple PDSCHs from a multi-TRP (also known as multiple PDSCHs) can be scheduled using a single DCI (single DCI, single PDCCH) (single-master mode, single-DCI based multi-TRP). Alternatively, multiple PDSCHs from a multi-TRP can be scheduled separately using multiple DCIs (multiple DCI, multiple PDCCHs) (multi-master mode, multi-DCI based multi-TRP).

[0055] Research is underway to support PDSCH (Transmission Block (TB) or Codeword (CW)) repetition across multiple TRPs in URLLC for multiple TRPs. Research is also underway to support repetition methods across multiple TRPs in the frequency domain, layer (spatial) domain, or time domain (URLLC schemes, e.g., schemes 1, 2a, 2b, 3, 4). In scheme 1, multiple PDSCHs from multiple TRPs are space-division multiplexed (SDM). In schemes 2a and 2b, PDSCHs from multiple TRPs are frequency-division multiplexed (FDM). In scheme 2a, for multiple TRPs, the redundancy version (RV) is the same. In scheme 2b, for multiple TRPs, the RV can 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 within a single time slot. In scheme 4, multiple PDSCHs from multiple TRPs are transmitted in different time slots.

[0056] In such a multi-TRP scenario, more flexible transmission control is possible when using high-quality channels.

[0057] To support multi-TRP transmission within a cell (with the same cell ID) and between cells (with different cell IDs) based on multiple PDCCHs, a control resource set (CORESET) within the PDCCH configuration information (PDCCH-Config) can also correspond to a single TRP in the RRC configuration information used to link multiple pairs of PDCCHs and PDSCHs with multiple TRPs.

[0058] The UE can also be determined to be a multi-DCI based multi-TRP if at least one of conditions 1 and 2 is met. In this case, the TRP can also be rewritten as the CORESET pool index.

[0059] [Condition 1]

[0060] It is set to a CORESET pool index.

[0061] [Condition 2]

[0062] Two distinct values ​​(e.g., 0 and 1) are set for the CORESET pool index.

[0063] The UE can also be determined as a multi-TRP based on a single DCI if the following conditions are met. In this case, the two TRPs can also be rewritten as two TCI states indicated by MAC CE / DCI.

[0064] [condition]

[0065] To indicate one or two TCI states corresponding to a code point in the TCI field within the DCI, use "Enhanced TCI States Activation / Deactivation for UE-specific PDSCH MAC CE".

[0066] The DCI used for common beam indication can be a UE-specific DCI format (e.g., DL DCI format (e.g., 1_1, 1_2), ULDCI format (e.g., 0_1, 0_2)) or a UE-group common DCI format.

[0067] (Unified / Common TCI Framework)

[0068] According to the unified TCI framework, the channels of UL and DL can be controlled through a common framework. The unified TCI framework may not specify the TCI status or spatial relationship for each channel as in Rel.15, but instead indicate a common beam and apply it to all channels of UL and DL. Alternatively, the common beam used by UL can be applied to all channels of UL, and the common beam used by DL can be applied to all channels of DL.

[0069] Research is underway on a single common beam for both DL and UL, or a common beam for DL ​​and a common beam for UL (two common beams in total).

[0070] The UE can also envision the same TCI state (joint TCI state, joint TCI state pool, joint common TCI state pool) for both UL and DL.

[0071] The RRC can also set multiple TCI states for both DL and UL (a common TCI state pool). Each of the multiple TCI states can also be a QCL type A / D RS. As a QCL type A / D RS, it can also be set as SSB, CSI-RS, or SRS. The MAC CE can also activate a portion of the set multiple TCI states. The DCI can also indicate at least one of the activated multiple TCI states.

[0072] The default beam alignment of UL and DL can also be achieved through MAC CE-based beam management (MAC CE level beam indication). The default TCI state of the PDSCH can also be updated to match the default UL beam (spatial relationship).

[0073] Alternatively, a common beam / unified TCI state can be indicated from the same TCI state pool (joint common TCI state pool) used by both UL and DL through DCI-based beam management (DCI-level beam indication). M (>1) TCI states can also be activated via MAC CE. The UL / DL DCI can also select one from the M activated TCI states. The selected TCI state can also be applied to the channels / RS of both UL and DL.

[0074] The UE can also envision different TCI states for UL and DL respectively (independent (separate) TCI state, independent TCI state pool, UL independent TCI state pool and DL independent TCI state pool, independent common TCI state pool, UL common TCI state pool and DL common TCI state pool).

[0075] RRC (parameters, information elements) can also set multiple TCI states (pools) for UL and DL channels respectively.

[0076] The MAC CE can also select (activate) one or more (e.g., multiple) TCI states (sets) for both the UL and DL channels. The MAC CE can also activate two sets of TCI states.

[0077] The DL DCI can also select (indicate) more than one (e.g., one) TCI state. This TCI state can also be applied to more than one DL channel. The DL channel can also be PDCCH / PDSCH / CSI-RS. The UE can also use the Rel.16 TCI state operation (TCI framework) to determine the TCI state of each DL channel / RS.

[0078] ULDCI can also select (indicate) more than one (e.g., one) TCI state. This TCI state can also be applied to more than one UL channel. The UL channel can also be PUSCH / SRS / PUCCH.

[0079] As an independent public TCI state pool, the following use cases 0, 1, and 2 are being studied.

[0080] [Use Case 0]

[0081] The UE uses different UL beams due to the Maximum Permitted Exposure (MPE).

[0082] Panel #1's UL is affected by the MPE issue, and the UE uses panel #2 in the UL.

[0083] [Use Case 1]

[0084] The UE uses different UL beams due to the varying UL signal strength.

[0085] The distance between the UE and TRP (cell, base station) #1 is longer than the distance between the UE and TRP #2. Here, the L1-RSRP of panel #1 is higher than that of panel #2, and the UL transmit power of panel #2 is higher than that of panel #1. The UE uses panel #1 in the DL from TRP #1 and uses panel #2 in the UL to TRP #2.

[0086] [Use Case 2]

[0087] The UE uses different UL beams due to UL load balancing.

[0088] The L1-RSRP of panel #1 is higher than that of panel #2, and the UL load of panel #2 is lower than that of panel #1. The UE uses panel #1 in the DL from TRP #1 and panel #2 in the UL to TRP #2.

[0089] Consider studying more scenarios with different requirements. For example, in multi-TRP transmission, high-speed train (HST) transmission, and inter-cell mobility during periods where there is a possibility that the UE is connected to two cells, the common beam for each TRP and cell can also be different.

[0090] In this scenario, the UE can also have multiple panels for FR2. In this case, the common beam for each UE panel can also be different.

[0091] Within the unified TCI framework, the UE can also support joint TCI based on the Rel.15 / 16 DL TCI framework. Regarding TCI, it may also include a TCI state containing at least one source RS that provides a reference (UE envision) for determining at least one QCL and spatial filter.

[0092] Under investigation: The UE uses a joint TCI (joint TCI pool) that includes references for both the DL beam and the UL beam; and the UE uses a separate TCI (pool) for the DL beam and a separate TCI (pool) for the UL beam.

[0093] Investigating: In an independent TCI pool, the UL TCI state is obtained from the same pool as the DL TCI state; and the ULTCI state is obtained from a pool different from the DL TCI state.

[0094] Within the independent TCI pool, the activation TCI pools for UL and DL can also be set / activated via RRC / MAC CE. The common activation TCI pool for UL and DL can also be set / activated via RRC / MAC CE.

[0095] In the DCI indication of the common beam (common TCI state), either the TCI field within the DL DCI can be reused, or a new field within the DL DCI (e.g., the unified TCI field) can be used. The DL DCI, the DCI for PDSCH scheduling, and DCI formats 1_1 and 1_2 can also be rewritten to each other.

[0096] In the DCI indication of the common beam (common TCI state), new fields within ULDCI (e.g., the unified TCI field) can also be used. ULDCI, PUSCH scheduling DCI, and DCI formats 0_1 and 0_2 can also be rewritten to each other.

[0097] Feedback on DCI indication for a common beam (common TCI state) is being investigated. If the reception of the DCI indication for a common beam fails, the base station will incorrectly identify the common beam. Therefore, the timing of common beam updates is being investigated: after the UE sends feedback on the DCI indication. For example, in the case of DLDCI indicating a common beam (TCI#2), the common beam (to TCI#2) is updated after the UE sends ACK / NACK (HARQ-ACK information) on PUCCH / PUSCH. Similarly, in the case of ULDCI indicating a common beam (TCI#2), the common beam (to TCI#2) is updated after the UE sends PUSCH.

[0098] (Simultaneous beam update of multiple CCs)

[0099] In Rel.16, a MAC CE can update the beam index (TCI status) of multiple CCs.

[0100] A UE can be configured with up to two applicable CC lists (e.g., applicable-CC-list) via RRC. When two applicable CC lists are configured, the two applicable CC lists can also correspond to the in-band CA in FR1 and the in-band CA in FR2, respectively.

[0101] The activation of the TCI state of the PDCCH MAC CE will activate the TCI state associated with the same CORESET ID on all BWP / CCs in the applicable CC list.

[0102] The activation of the TCI status of PDSCH MAC CE will activate the TCI status on all BWP / CCs in the CC list.

[0103] The activation MAC CE for spatial relationships of A-SRS / SP-SRS activates spatial relationships associated with the same SRS resource ID on all BWP / CCs within the applicable CC list.

[0104] The UE is configured to represent a list of applicable CCs (CCs) for CCs #0, #1, #2, and #3, and a list of 64 TCI states for each CC's CORESET or PDSCH. If a TCI state of CC #0 is activated via the MAC CE, the corresponding TCI states in CCs #1, #2, and #3 are also activated.

[0105] Research is underway to explore whether simultaneous beam updates can be applied only to single TRP scenarios.

[0106] For PDSCH, the UE can also be based on the following procedure A.

[0107] [Process A]

[0108] The UE receives an activation command for mapping up to eight TCI states for code points in a DCI field (TCI field) within a CC / DLBWP or within a set of CC / BWPs. When a set of TCI state IDs is activated for a set of CC / DLBWPs, the applicable list of CCs is determined by the CCs indicated in the activation command, and the same set of TCI states is applied to all DLBWPs within the indicated CCs. A set of TCI state IDs can be activated for a set of CC / DLBWPs only if the UE is not provided with multiple different values ​​for the CORESET Pool Index in the CORESET Information Element (ControlResourceSet) and is not provided with at least one TCI code point mapped to two TCI states.

[0109] For PDCCH, UE can also be based on the following procedure B.

[0110] [Process B]

[0111] If the UE is provided with at most two lists of cells with simultaneously active TCI states based on at least one of the simultaneous TCI update lists (simultaneousTCI-CellList and simultaneousTCI-UpdateListSecond-r16), then the UE applies the antenna port quasi-co-location (QCL) provided by the TCI state having the same active TCI state ID value to all configured cells in the DLBWP with index p in one of the lists determined according to the serving cell index provided by the MAC CE command for all configured cells. The simultaneous TCI cell list can be provided for simultaneous TCI state activation only if the UE is not provided with multiple different values ​​for the CORESET Pool Index in the CORESET Information Element (ControlResourceSet) and is not provided with at least one TCI code point mapped to two TCI states.

[0112] For semi-persistent (SP) / aperiodic (AP)-SRS, the UE can also be based on the following process C.

[0113] [Process C]

[0114] When a set of CCs / BWPs is activated / updated via MAC CE for the spatial relation information (spatialRelationInfo) of SPs or APs-SRS resources set through the SRS resource information element (higher-level parameter SRS-Resource), the applicable list of CCs is indicated by the simultaneous spatial update list (higher-level parameters simultaneousSpatial-UpdateList-r16 or simultaneousSpatial-UpdateListSecond-r16). Within all BWPs in the indicated CC, this spatial relation information is applied to SPs or APs-SRS resources with the same SRS resource ID. If the UE is not provided with multiple different values ​​for the CORESET Pool Index within the CORESET Information Element (ControlResourceSet) and is not provided with at least one TCI code point mapped to two TCI states, the spatial relation information of the SP or AP-SRS resources set by the SRS Resource Information Element (higher-layer parameter SRS-Resource) for a set of CC / BWP is activated / updated via MAC CE.

[0115] Simultaneous TCI Cell List and simultaneous TCI Update List (at least one of simultaneous TCI UpdateList1-r16 and simultaneous TCI UpdateList2-r16) are lists of serving cells whose TCI relationships can be updated simultaneously using MAC CE. simultaneousTCI UpdateList1-r16 and simultaneousTCI UpdateList2-r16 do not contain the same serving cells.

[0116] Simultaneously, the spatial update list (at least one of the higher-level parameters simultaneousSpatial-UpdatedList1-r16 and simultaneousSpatial-UpdatedList2-r16) is a list of serving cells whose spatial relationships can be updated simultaneously using MAC CE. simultaneousSpatial-UpdatedList1-r16 and simultaneousSpatial-UpdatedList2-r16 do not contain the same serving cells.

[0117] Here, the simultaneous TCI update list and the simultaneous space update list are set via RRC, the CORESET pool index of CORESET is set via RRC, and the TCI code points mapped to the TCI state are indicated via MAC CE.

[0118] (Radio Link Monitoring (RLM))

[0119] In NR, Radio Link Monitoring (RLM) is utilized.

[0120] In NR, the base station can also use higher-layer signaling to configure the Radio Link Monitoring Reference Signal (RLM-RS) for the UE on a per-BWP basis. The UE can also receive configuration information for the RLM (e.g., the "RadioLinkMonitoringConfig" information element of the RRC).

[0121] The configuration information used by the RLM can also include failure detection resource configuration information (e.g., the higher-level parameter "failureDetectionResourcesToAddModList"). The failure detection resource configuration information can also include parameters related to RLM-RS (e.g., the higher-level parameter "RadioLinkMonitoringRS").

[0122] Parameters related to RLM-RS may also include: information corresponding to the purpose of the RLM, and indexes corresponding to the resources of the RLM-RS (e.g., the indexes contained in the higher-layer parameter "failureDetectionResources" (RadioLinkMonitoringRS within failureDetectionResourcesToAddModList)). This index may be, for example, an index of the CSI-RS resource settings (e.g., a non-zero power CSI-RS resource ID) or an SS / PBCH block index (SSB index). The purpose information may also indicate beam failure, (cell-level) radio link failure (Radio LinkFailure(RLF)), or both.

[0123] The UE can also determine the RLM-RS resource based on the index corresponding to the RLM-RS resource and use the RLM-RS resource to implement RLM.

[0124] In the RLM of Rel.16, the UE follows the procedure below.

[0125] [process]

[0126] If the UE is not provided with RLM-RS (RadioLinkMonitoringRS) and the UE is provided with a TCI state that includes more than one CSI-RS for PDCCH reception, the UE follows procedures 1 to 4 below.

[0127] [[Process 1]]

[0128] If the active TCI state for PDCCH reception contains only one RS, the UE will use the RS provided for the active TCI state for PDCCH reception for RLM.

[0129] [[Process 2]]

[0130] When the active TCI state for PDCCH reception includes two RSs, the UE assumes that one RS has QCL type D, and the UE will use this RS with QCL type D for RLM. The UE does not assume that both RSs have QCL type D.

[0131] [[Process 3]]

[0132] UEs are not required to use aperiodic or semi-persistent RS for RLM.

[0133] [[Process 4]]

[0134] For L max =4, starting from the minimum monitoring period, the UE sequentially selects the N provided for the active TCI state used for PDCCH reception from multiple CORESETs associated with multiple search space sets. RLM There are 1 RS. When more than 1 CORESET is associated with multiple search space sets with the same monitoring period, the UE determines the order of CORESETs starting from the highest CORESET.

[0135] Here, L max This is the maximum number of SS / PBCH block indices within the cell. The maximum number of SS / PBCH blocks transmitted within a half-frame is L. max .

[0136] Thus, even when the UE is not provided with RLM-RS, the UE performs an implicit RLM-RS decision, using the active TCI state for PDCCH reception for RLM. In L maxWhen N=4, the UE first selects N in ascending order of the monitoring period of the search space set, and then in descending order of the CORESET index. RLM RS. Select CORESET.

[0137] For the link recovery process and RLM, the UE can be configured with a maximum of N. LR-RLM One RLM-RS. From N LR-RLM In each RLM-RS, depending on L max And at most N RLM One RLM-RS was used for RLM. In Rel.16, in L max When N = 4, RLM =2, in L max When N = 8, RLM =4, in L max When N = 64, RLM =8.

[0138] (Beam Failure Detection (BFD) / Beam Failure Recovery (BFR))

[0139] In NR, beamforming is used for communication. For example, the UE and the base station (e.g., gNB (gNodeB)) can use beams used for transmitting signals (also called transmit beams, Tx beams, etc.) and beams used for receiving signals (also called receive beams, Rx beams, etc.).

[0140] When using beamforming, it is assumed that the radio link quality is susceptible to interference from obstacles, thus degrading the quality of the radio link. This degradation in radio link quality raises concerns about frequent radio link failures (RLFs). If an RLF occurs, cell reconnection is required, therefore frequent RLFs can lead to a decrease in system throughput.

[0141] In Natural Radio Networks (NR), to suppress Recurrent Beam Failure (RLF), research is underway on implementing a switch to other beams (also known as Beam Recovery (BR), Beam Failure Recovery (BFR), L1 / L2 (Layer 1 / Layer 2) beam recovery, etc.) when specific beam quality deteriorates. Additionally, the BFR process can also be simply referred to as BFR.

[0142] In addition, beam failure (BF) in this disclosure can also be referred to as link failure.

[0143] Figure 1 This is a diagram illustrating an example of the beam recovery process in Rel.15NR. The number of beams is an example, and is not limited thereto. In the initial state (step S101), the UE performs a measurement based on the reference signal (ReferenceSignal(RS)) resources transmitted using two beams.

[0144] The RS can also be at least one of a Synchronization Signal Block (SSB) and a Channel State Information RS (CSI-RS). Additionally, the SSB can also be referred to as an SS / PBCH (Physical Broadcast Channel) block, etc.

[0145] The RS can also be at least one of the following: Primary SS (PSS), Secondary SS (SSS), Mobility Reference Signal (MRS), signals contained in an SSB, SSB, CSI-RS, DeModulation Reference Signal (DMRS), beam-specific signals, or a signal formed by extending or modifying them. The RS measured in step S101 can also be referred to as an RS used for beam failure detection (Beam Failure Detection RS (BFD-RS)), or an RS used in beam recovery (BFR-RS), etc.

[0146] In step S102, the UE cannot detect the BFD-RS (or the RS reception quality is degraded) because the radio waves from the base station are obstructed. Such obstruction may occur due to obstacles between the UE and the base station, fading, interference, etc.

[0147] The UE detects a beam failure when certain conditions are met. For example, if the BLER (Block Error Rate) is less than a threshold for all configured BFD-RS (BFD-RS resource settings), the UE can also detect a beam failure. If a beam failure is detected, the lower layer (PHY layer) of the UE can also notify (indicate) the higher layer (MAC layer) of the beam failure instance.

[0148] Furthermore, the benchmark for judgment is not limited to BLER, but can also be the reference signal received power in the physical layer (Layer 1 Reference Signal Received Power (L1-RSRP)). Additionally, beam failure detection can be implemented based on the downlink control channel (Physical Downlink Control Channel (PDCCH)) or further, either instead of RS measurement or based on RS measurement. BFD-RS can also be envisioned as quasi-co-location (QCL) with the DMRS of the PDCCH monitored by the UE.

[0149] Here, QCL refers to an indicator representing the statistical properties of a channel. For example, if a signal / channel has a QCL relationship with other signals / channels, it can also mean that at least one of the following is the same among these different signals / channels: Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (e.g., spatial Rx parameter). (Regarding at least one of these, it is the QCL.)

[0150] Additionally, the spatial reception parameters may correspond to the UE's receive beam (e.g., receive analog beam), and the beam may be determined based on the spatial QCL. The QCL (or at least one element of the QCL) in this disclosure may also be rewritten as sQCL (spatial QCL).

[0151] Information related to BFD-RS (e.g., RS index, resources, quantity, number of ports, precoding, etc.) and information related to beam failure detection (BFD) (e.g., the aforementioned thresholds) can also be set (notified) to the UE using higher-layer signaling. Information related to BFD-RS can also be referred to as information related to BFR resources, etc.

[0152] The higher layers of the UE (e.g., the MAC layer) may also start a specific timer (also referred to as a beam failure detection timer) upon receiving a beam failure instance notification from the UE's PHY layer. The UE's MAC layer may also trigger a BFR (e.g., start any of the random access procedures described later) after receiving a certain number of beam failure instance notifications (e.g., beamFailureInstanceMaxCount set via RRC) before the timer expires.

[0153] Even in the absence of notification from the UE, or in the absence of a specific signal received from the UE (beam recovery request in step S104), the base station can also determine that the UE has detected a beam failure.

[0154] In step S103, for beam recovery, the UE begins searching for a new candidate beam for communication. The UE can also select a new candidate beam corresponding to a specific RS by measuring that RS. The RS measured in step S103 can also be referred to as a new candidate RS, an RS used for new candidate beam identification (New Candidate Beam Identification RS (NCBI-RS)), CBI-RS, CB-RS (Candidate Beam RS), etc. NCBI-RS can be the same as or different from BFD-RS. Additionally, a new candidate beam can also be simply referred to as a candidate beam or candidate RS.

[0155] The UE can also select the beam corresponding to an RS that meets specific conditions as a new candidate beam. For example, the UE can also select a new candidate beam based on RSs in the set NCBI-RS whose L1-RSRP exceeds a threshold. Furthermore, the criterion for judgment (reference) is not limited to L1-RSRP. L1-RSRP related to SSB can also be called SS-RSRP. L1-RSRP related to CSI-RS can also be called CSI-RSRP.

[0156] Information related to NCBI-RS (e.g., RS resources, quantity, number of ports, precoding, etc.) and information related to the New Candidate Beam Identifier (NCBI) (e.g., the aforementioned threshold) can also be set (notified) to the UE using higher-layer signaling. Information related to the New Candidate RS (or NCBI-RS) can also be obtained based on information related to BFD-RS. Information related to NCBI-RS can also be referred to as information related to NCBI resources, etc.

[0157] In addition, BFD-RS, NCBI-RS, etc. can also be rewritten as Radio Link Monitoring Reference Signal (RLM-RS).

[0158] In step S104, the UE that has determined the new candidate beam sends a Beam Failure Recovery reQuest (BFRQ). The Beam Failure Recovery reQuest can also be referred to as a Beam Recovery Request signal, Beam Failure Recovery Request signal, etc.

[0159] BFRQ can also be transmitted using at least one of the following: Physical Uplink Control Channel (PUCCH), Physical Random Access Channel (PRACH), Physical Uplink Shared Channel (PUSCH), or Configured Grant (CG) PUSCH.

[0160] The BFRQ may also include information about the new candidate beam / new candidate RS identified in step S103. Resources used for the BFRQ may also be associated with this new candidate beam. Beam information may also be provided using beam indices (BeamIndex(BI)), port indices of specific reference signals, RS indices, resource indices (e.g., CSI-RS Resource Indicator(CRI)), SSB Resource Indicator(SSBRI)), etc.

[0161] In Rel.15NR, research is underway on two BFR methods: CB-BFR (Contention-Based BFR) based on a contention-based random access (RA) procedure, and CF-BFR (Contention-Free BFR) based on a non-contention-based random access procedure. In both CB-BFR and CF-BFR, the UE can utilize PRACH resources to transmit preambles (also known as RA preambles, Physical Random Access Channel (PRACH) preambles, RACH preambles, etc.) as BFRQs.

[0162] In CB-BFR, the UE can also transmit a preamble randomly selected from one or more preambles. Conversely, in CF-BFR, the UE can also transmit a preamble assigned by the base station in a UE-specific manner. In CB-BFR, the base station can also assign the same preamble to multiple UEs. In CF-BFR, the base station can also assign a preamble individually to each UE.

[0163] Additionally, CB-BFR and CF-BFR can also be referred to as CB PRACH-based BFRs (contention-based PRACH-based BFRs, CBRA-BFR) and CF PRACH-based BFRs (contention-free PRACH-based BFRs, CFRA-BFR) respectively. CBRA-BFR can also be referred to as BFR using CBRA. CFRA-BFR can also be referred to as BFR using CFRA.

[0164] In either the CB-BFR or CF-BFR scenario, information related to PRACH resources (RA preambles) can be communicated via higher-layer signaling (RRC signaling, etc.). For example, this information may include correspondences between detected DL-RS (beams) and PRACH resources, or different PRACH resources may be associated for each DL-RS.

[0165] In step S105, the base station that detected the BFRQ sends a response signal (also known as a gNB response, etc.) to the BFRQ from the UE. This response signal may also contain reconstruction information for one or more beams (e.g., structural information of DL-RS resources).

[0166] The response signal can also be transmitted, for example, in the UE common search space of the PDCCH. The response signal can also be notified using a PDCCH (DCI) scrambled with a UE identifier (e.g., Cell-Radio RNTI (C-RNTI)). The UE can also determine the transmitted beam and received beam used based on beam reconstruction information.

[0167] The UE can also monitor the response signal based on at least one of the control resource set (CORESET) used by the BFR and the search space set used by the BFR.

[0168] Regarding CB-BFR, if the UE receives the PDCCH corresponding to its own C-RNTI, it can also be determined that the contention resolution has been successful.

[0169] The processing in step S105 can also be configured to allow the UE to monitor the response from the base station (e.g., gNB) to the BFRQ. This period can also be referred to as the gNB response window, gNB window, beam recovery request response window, etc. If no gNB response is detected during this window period, the UE can also retransmit the BFRQ.

[0170] In step S106, the UE may also send a message to the base station indicating that beam reconfiguration is complete. This message can be sent via either PUCCH or PUSCH.

[0171] A beam recovery success (BR success) could also indicate that step S106 has been reached. On the other hand, a beam recovery failure (BR failure) could also be equivalent to the BFRQ transmission reaching a certain number of times, or the beam-failure-recovery-timer expiring.

[0172] In Rel.15, support is provided for beam recovery procedures (e.g., BFRQ notification) for beam failures detected in SpCell (PCell / PSCell) using random access procedures. On the other hand, in Rel.16, support is provided for beam recovery procedures (e.g., BFRQ notification) for beam failures detected in SCell using at least one of the following: PUCCH (e.g., Scheduling Request (SR)) transmission for BFR and MAC CE (e.g., UL-SCH) transmission for BFR.

[0173] For example, the UE can also use a MAC CE-based two-step process to send information related to beam failure. The information related to beam failure may include information about the cell where the beam failure was detected, and information about new candidate beams (or new candidate RS indices).

[0174] [Step 1]

[0175] If a beam failure is detected, a PUCCH-BFR (Schedule Request (SR)) can be sent from the UE to the PCell / PSCell. Then, a UL clearance (DCI) for step 2 below can be sent from the PCell / PSCell to the UE. If a beam failure is detected, and a MAC CE (or UL-SCH) for sending information related to a new candidate beam is available, step 1 (e.g., PUCCH transmission) can be omitted, and step 2 (e.g., MAC CE transmission) can be performed instead.

[0176] [Step 2]

[0177] Next, the UE can also transmit information related to the detected (failed) cell (e.g., cell index) and information related to the new candidate beam to the base station (PCell / PSCell) via the uplink channel (e.g., PUSCH) using MAC CE. Afterwards, following the BFR process, a specific period (e.g., 28 symbols) after receiving an acknowledgment signal from the base station, the QCL of the PDCCH / PUCCH / PDSCH / PUSCH is updated to the new beam.

[0178] Furthermore, the numbering of these steps is merely for illustrative purposes; multiple steps can be combined or their order can be changed. Additionally, whether or not to implement BFR can be configured for the UE using higher-layer signaling.

[0179] (BFD-RS)

[0180] In Rel.16, for each BWP of a serving cell, the UE can be provided with a set of periodic (P)-CSI-RS resource setting indexes via failure detection resources (failureDetectionResources, failureDetectionResourcesToAddModList, RadioLinkMonitoringConfig), and at least one set of P-CSI-RS resource setting indexes and SS / PBCH block indexes via candidate beam RS list (candidateBeamRSList), extended candidate beam RS list (candidateBeamRSListExt-r16), or SCell candidate beam RS list (candidateBeamRSSCellList-r16).

[0181] Here, the hyphen "q0" is an overlined representation of "q0". From now on, "q0" will simply be referred to as "q0". The hyphen "q1" is an overlined representation of "q1". From now on, "q1" will simply be referred to as "q1".

[0182] The set q0 of P-CSI-RS resources provided by failure detection resources can also be called explicit BFD-RS.

[0183] The UE can also use RS resources corresponding to the indexes contained in at least one set of set q0 and set q1 to perform L1-RSRP measurements, etc., to detect beam failure.

[0184] Furthermore, the aforementioned high-level parameters, which provide information representing the index corresponding to the BFD resource, can also be interchanged with the BFD resource being set, the BFD-RS being set, etc. In this disclosure, the set q0 of the BFD resource, the periodic CSI-RS resource setting index, or the SSB index, the BFD-RS, the BFD-RS set, and the RS set can also be interchanged.

[0185] If the UE is not provided with failure detection resources q0 for a BWP of its serving cell, it is determined that: set q0 includes a P-CSI-RS resource setting index, which has the same value as the RS index in the RS set indicated by the TCI state, where the TCI state is the TCI state corresponding to the CORESET used by the UE for PDCCH monitoring. If there are two RS indices within a TCI state, set q0 includes an RS index with QCL type D setting for the corresponding TCI state. The UE assumes that set q0 contains at most two RS indices. The UE is assumed to have a single-port RS within set q0.

[0186] This set q0 can also be referred to as implicit BFD-RS.

[0187] In this way, the UE determines the BFD-RS (RS set) through the PDCCH using the TCI state. The UE assumes that the RS set contains a maximum of 2 RSs.

[0188] (Explicit BFD-RS / Implicit BFD-RS)

[0189] In the physical layer within the UE, for the threshold Q out,LRThe radio link quality is evaluated based on the resource setting set q0. For set q0, the UE evaluates the radio link quality based on the P-CSI-RS resource setting that is quasi-co-located with the DM-RS received through the PDCCH monitored by the UE, or the SS / PBCH block on the PCell or PSCell that is quasi-co-located with the DM-RS received through the PDCCH monitored by the UE.

[0190] In other words, whether it is implicit BFD-RS or explicit BFD-RS, BFD-RS and PDCCH become QCL.

[0191] Regarding BFR, the UE may also follow at least one of the following operations: Operation 1 (BFR for SCell) and Operation 2 (BFR for SpCell).

[0192] [Operation 1]

[0193] The UE can also be configured to send a PUCCH with a link recovery request (LRR) via BFR using the scheduling request ID (schedulingRequestIDForBFR). The UE can then send a PUCCH with a link recovery request (LRR) in the first PUSCH. out,LR At least one MAC CE (BFR MAC CE) provides an index for at least one corresponding SCell with poor radio link quality. If this index is set, it is for the corresponding SCell via an index q provided by a higher layer for the P-CSI-RS setting or SS / PBCH block. new After 28 symbols from the last symbol received from a specific PDCCH, the UE may also follow at least one of the following operations 1-1 and 1-2. Regarding the reception of a specific PDCCH, a PUSCH transmission with the same HARQ process number as the transmission of the first PUSCH is scheduled, and with a DCI format having a toggled new data indicator (NDI) field value.

[0194] [[Operation 1-1]]

[0195] If it exists, the UE uses the sum and the corresponding index q. new The antenna port QCL parameters are the same as those of the associated antenna port, and the PDCCH in all CORESETs on the SCell indicated by MAC CE is monitored.

[0196] [[Operations 1-2]]

[0197] If conditions 1 to 3 below are met, the UE uses the sum and index q. new For spatial domain filters with the same corresponding spatial domain filter, the transmit power is used, where q is the value of the transmit power. u =0, q d =q new And with power at l=0, send the PUCCH on PUCCH-SCell.

[0198] [[[Condition 1]]] The UE is provided with PUCCH spatial relation information (PUCCH-SpatialRelationInfo) for PUCCH.

[0199] [[[Condition 2]]] A PUCCH with LRR is not sent or is sent on PCell or PSCell.

[0200] [[[Condition 3]]] PUCCH-SCell is included in the SCell indicated by MAC CE.

[0201] Here, the subcarrier spacing (SCS) setting for the aforementioned 28 symbols is the minimum value of the SCS setting for the active DL BWP used for PDCCH reception and the SCS setting for the active DL BWP of at least one SCell.

[0202] q new It can also be the index of a new candidate beam (e.g., SSB / CSI-RS) selected by the UE during the BFR process and reported to the network via the corresponding PRACH (or the index of a new beam discovered during the BFR process).

[0203] Under normal circumstances, q u It can also be the PUCCH ID (p0-PUCCH-Id) representing the PUCCH P0 (P0-PUCCH) within the PUCCH P0 set (p0-Set). l can also be referred to as the index of the power control adjustment state, the index of the PUCCH power control adjustment state, the closed-loop index, etc. q d It can also be an index of the path loss reference RS (e.g., set via PUCCH-PathlossReferenceRS).

[0204] [Operation 2]

[0205] The UE can also receive PRACH transmission settings (PRACH-ResourceDedicatedBFR). For PRACH transmissions that conform to the antenna port QCL parameters, the UE monitors a specific PDCCH, which is associated with the P-CSI-RS resource settings or SS / PBCH blocks, and these P-CSI-RS resource settings or SS / PBCH blocks are associated with an index q provided by higher layers in time slot n. new Associativity is established. A specific PDCCH is a PDCCH within a search space set provided with a recovery search space ID (recoverySearchSpaceId) for detection, using a DCI format with a CRC scrambled by C-RNTI or MCS-C-RNTI. Detection of this DCI format begins in time slot n+4 within the window set by BeamFailureRecoveryConfig. Monitoring of PDCCHs within the search space set provided with the recovery search space ID and reception of corresponding PDSCHs continue until the UE receives activation of at least one parameter for TCI state or PDCCH with TCI state append list (tci-StatesPDCCH-ToAddList) and PDCCH with TCI state release list (tci-StatesPDCCH-ToReleaseList) via a higher layer. The UE assumes that: and with index q new The antenna ports that are associated have the same QCL parameters.

[0206] The UE can also follow the following operation 2-1.

[0207] [[Operation 2-1]]

[0208] After the UE detects a DCI format with a CRC scrambled by C-RNTI or MCS-C-RNTI within the search space set provided by the recovery search space ID, the UE continuously monitors PDCCH candidates within the search space set provided by the recovery search space ID until the UE receives a MAC CE activation command for at least one of the TCI state or the PDCCH append list and the PDCCH release list with TCI state.

[0209] For BFRs of PCell / SCell (SpCell / SCell) based on CBRA / CFRA procedures, BFD-RS can be explicitly set via RRC, or it can be left unset. If BFD-RS is not set, the UE will assume the periodic (P)-CSI-RS or SSB of QCL type D with the PDCCH as BFD-RS. In Rel. 15 / 16, the UE can monitor up to two BFD-RSs.

[0210] In Rel.15 / 16, the UE continuously monitors the BFD-RS until the explicitly configured BFD-RS (explicit BFD-RS) is reset or deactivated via RRC. If the BFD-RS is explicitly configured via RRC, and the UE uses the same BFD-RS to perform another BFD after a BFD has occurred and a BFR has ended, a BFR may sometimes occur again.

[0211] For example, consider a situation where P-CSI-RS#1 is configured as a BFD-RS via RRC. After BFR is performed, a different beam is used for the PDCCH following BFR, compared to P-CSI-RS#1 (which is configured as QCL type D with its TCI state). According to existing specifications, BFR BFD measurements are performed using the P-CSI-RS#1 configured before BFR. In other words, even with good actual communication quality, BFR may sometimes be performed again (repeatedly) because a BFD-RS unrelated to communication quality is used for BFD.

[0212] Therefore, it is being studied that, for operation 1, if explicit BFD-RS is set before the SCell beam failure, the UE will stop monitoring the explicit BFD-RS after receiving the SCell BFR response. For example, if the UE performs at least one of the aforementioned operations 1-1 and 1-2, it will perform the following operation 1-3.

[0213] [[Operations 1-3]]

[0214] If set q0 is provided with failure detection resources (failureDetectionResource) or beam failure detection resource list (BeamFailureDetectionResourceList, failureDetectionResourcesToAddModList) via higher-layer parameters, the UE stops monitoring set q0.

[0215] Furthermore, research is underway regarding Operation 2, where, in the case of an explicit BFD-RS being set before the SpCell beam failure, the UE stops monitoring the explicit BFD-RS after receiving the SpCell BFR response. For example, research is underway regarding the UE performing Operation 2-2 instead of the aforementioned Operation 2-1.

[0216] [[Operation 2-2]]

[0217] After the UE detects a DCI format with a CRC scrambled by C-RNTI or MCS-C-RNTI within the search space set provided by the recovery search space ID, the UE continues to monitor PDCCH candidates within the search space set provided by the recovery search space ID until the UE receives a MAC CE activation command for at least one of the TCI state or PDCCH TCI state append list and PDCCH TCI state release list. If set q0 is provided by the failure detection resource, the UE stops monitoring set q0.

[0218] Extensions related to beam management for simultaneous multi-TRP transmission using multi-panel reception are under investigation.

[0219] With implicit BFD-RS settings in place, the following options 1 and 2 are being investigated.

[0220] [Option 1]

[0221] The BFD-RS set k can also be derived from the QCL type DRS of the TCI state of the CORESET set within the CORESET subset k. For example, k is 0 or 1. If no QCL type DRS is set, the BFD-RS set k can also be derived from the QCL type A of the TCI state of the CORESET set within the CORESET subset k. This option can also be applied to multi-TRP based on a single DCI and multi-TRP based on multiple DCIs.

[0222] [Option 2]

[0223] The BFD-RS set k can also be derived from the QCL type DRS of the TCI state of the CORESET set within the CORESET pool index k. For example, k is 0 or 1. If no QCL type DRS is set, the BFD-RS set k can also be derived from the QCL type A of the TCI state of the CORESET set within the CORESET pool index k. This option can also be applied to multiple TRPs based on multiple DCIs.

[0224] For multi-DCI-based multi-TRPs, option 2 is preferred. However, for single-DCI-based multi-TRPs, there is a possibility that there is no CORESET subset setting (the CORESET subset setting is the same as that for multi-DCI-based multi-TRPs). In this case, option 1 is not implemented.

[0225] Extensions related to beam management for simultaneous multi-TRP transmission using multi-panel reception are under investigation.

[0226] The possibility of supporting per-TRP BFR (per-TRP based beam failure recovery) for multiple TRPs based on single DCI / multi-DCI is under investigation. To achieve per-TRP BFR, issues arise regarding base station (e.g., gNB) response extension, UE operation for DL ​​and UL channels / RS QCL / spatial relationship assumptions / UL power control after base station response reception, etc.

[0227] In the BFR process in multi-panel / multi-TRP, multiple sets (settings) of BFD-RS are being studied for multi-TRP based on single DCI and multi-DCI based multi-TRP.

[0228] The research is underway to investigate how, for multiple TRPs based on a single DCI, the BFR of each TRP is set via RRC and the BFD-RS is implicitly determined without being explicitly set.

[0229] In Rel.15 / 16, BFR-RS / RLM-RS are set via RRC information elements and updated via RRC. Regarding BFR-RS / RLM-RS, it is preferable that they be identical to the RS of the CORESET's TCI state (specifically, QCL type D RS) (QCL is performed with the PDCCH (CORESET's TCI state)). Otherwise, the UE cannot recover from CORESET beam failure / link failure.

[0230] When BFR-RS / RLM-RS is not set via RRC information elements, there exists a CORESET TCI state (specifically, QCL type D RS) as the rule used by BFR-RS / RLM-RS. In this case, BFR-RS / RLM-RS automatically becomes the same as the CORESET TCI state (specifically, QCL type D RS).

[0231] When BFR-RS / RLM-RS is set via RRC information elements, BFR-RS / RLM-RS is not limited to being the same as the CORESET TCI state (in particular, QCL type D RS).

[0232] For explicit BFD-RS, based on the existing specifications, when the CORESET TCI state is updated via MAC CE (UE-specific PDCCH TCI State Indication for UE-specific PDCCH MAC CE), the network (NW) needs to reconfigure BFD-RS via RRC, which will cause latency and overhead.

[0233] (PDCCH SFN scheme)

[0234] To improve the reliability of PDCCH, iterative PDCCH from multiple TRPs in the time, spatial, and frequency domains is being investigated.

[0235] In the PDCCH SFN scheme (PDCCH repetition using frequency division multiplexing (SDM)), multiple TCI states are set / notified for a single CORESET, and DCI (PDCCH) is transmitted from multiple TRPs (multiple TRPs transmitting DCI at the same time / frequency). In the PDCCH SFN scheme, the PDCCH DMRS in all resource element groups (REGs) / control channel elements (CCEs) of the PDCCH can also be associated with two TCI states. In this case, multiple TCI states are set / notified for one CORESET via the RRC information element / MAC CE.

[0236] In this disclosure, SDM and SFN can be rewritten interchangeably.

[0237] However, the update method for BFR-RS / RLM-RS is unclear when multiple TCI states are set / notified for a single CORESET. This lack of clarity raises concerns about potential degradation in communication quality and throughput.

[0238] Therefore, the inventors of this invention conceived of a method for updating BFD-RS / RLM-RS.

[0239] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The wireless communication methods involved in each embodiment can be applied individually or in combination.

[0240] In this disclosure, "A / B / C" and "at least one of A, B, and C" can be rewritten as each other. In this disclosure, cell, serving cell, CC, carrier, BWP, DL BWP, UL BWP, active DL BWP, active UL BWP, and band domain can also be rewritten as each other. In this disclosure, index, ID, indicator, and resource ID can also be rewritten as each other. In this disclosure, support, control, capable of control, operation, and capable of operation can also be rewritten as each other.

[0241] In this disclosure, configure, activate, update, indicate, enable, specify, and select can also be overridden with each other.

[0242] In this disclosure, higher-layer signaling may be any one or a combination of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, etc. In this disclosure, RRC, RRC signaling, RRC parameters, higher layers, higher-layer parameters, RRC information elements (IEs), and RRC messages may also be rewritten.

[0243] MAC signaling can also use MAC Control Element (MAC CE) or MAC Protocol Data Unit (PDU). Broadcast information can also be, for example, Master Information Block (MIB), System Information Block (SIB), Remaining Minimum System Information (RMSI), or Other System Information (OSI).

[0244] In this disclosure, MAC CE and activation / deactivation commands can also be rewritten.

[0245] In this disclosure, beam, spatial domain filter, spatial settings, TCI state, UL TCI state, unified TCI state, unified beam, common TCI state, common beam, TCI concept, QCL concept, QCL parameters, spatial domain receive filter, UE spatial domain receive filter, UE receive beam, DL beam, DL receive beam, DL precoding, DL precoder, DL-RS, RS of QCL type D in TCI state / QCL concept, RS of QCL type A in TCI state / QCL concept, spatial relationship, spatial domain transmit filter, UE spatial domain transmit filter, UE transmit beam, UL beam, UL transmit beam, UL precoding, UL precoder, and PL-RS can also be mutually modified. In this disclosure, QCL type X-RS, DL-RS associated with QCL type X, DL-RS having QCL type X, source of DL-RS, SSB, CSI-RS, and SRS can also be mutually modified.

[0246] In this disclosure, the panel, uplink (UL) transmitting entity, TRP, spatial relationship, control resource set (CORESET), PDSCH, codeword, base station, antenna port of a signal (e.g., DeModulation Reference Signal (DMRS) port), antenna port group of a signal (e.g., DMRS port group), group for multiplexing (e.g., Code Division Multiplexing (CDM) group, reference signal group, CORESET group), CORESET pool, CORESET subset, CW, redundancy version (RV)), and layer (MIMO layer, transmitting layer, spatial layer) can also be overridden. Furthermore, the panel identifier (ID) and the panel can also be overridden. In this disclosure, the TRP ID, TRP association ID, CORESET pool index, the position (ordinal number, first TCI state, or second TCI state) of one of two TCI states corresponding to a code point in a field within the DCI, and the TRP can also be overridden.

[0247] In this disclosure, the TRP, the transmitting point, the panel, the DMRS port group, the CORESET pool, and one of the two TCI states associated with a code point in the TCI field can also be overwritten.

[0248] In this disclosure, single TRP, single TRP system, single TRP transmission, and single PDSCH can also be mutually rewritten. In this disclosure, multiple TRP, multiple TRP system, multiple TRP transmission, and multiple PDSCH can also be mutually rewritten. In this disclosure, single DCI, single PDCCH, multiple TRP based on single DCI, and activation of two TCI states on at least one TCI code point can also be mutually rewritten.

[0249] In this disclosure, a single TRP, a channel using a single TRP, a channel using a TCI state / spatial relationship, multiple TRPs not activated by RRC / DCI, multiple TCI states / spatial relationships not activated by RRC / DCI, and a CORESET pool index value not set for any CORESET and no code points of the TCI field mapped to two TCI states can also be rewritten to each other.

[0250] In this disclosure, multiple TRPs, channels using multiple TRPs, channels using multiple TCI states / spatial relationships, multiple TRPs activated via RRC / DCI, multiple TCI states / spatial relationships activated via RRC / DCI, and at least one of multiple TRPs based on a single DCI and multiple TRPs based on multiple DCIs can also be mutually modified. In this disclosure, multiple TRPs based on multiple DCIs, and setting a CORESET pool index value for CORESET, can also be mutually modified. In this disclosure, multiple TRPs based on a single DCI, and at least one code point of the TCI field mapped to two TCI states, can also be mutually modified.

[0251] In this disclosure, TRP#1 (first TRP) can correspond to either CORESET pool index = 0 or the first TCI state among two TCI states corresponding to a code point in the TCI field. TRP#2 (second TRP) can correspond to either CORESET pool index = 1 or the second TCI state among two TCI states corresponding to a code point in the TCI field.

[0252] In this disclosure, DMRS, DMRS port, and antenna port can also be rewritten.

[0253] UL DCI, the DCI for scheduling UL channels (e.g., PUSCH), and the DCI format 0_x (x = 0, 1, 2, ...) can also be rewritten. DL DCI, the DCI for scheduling DL channels (PDSCH), and the DCI format 1_x (x = 0, 1, 2, ...) can also be rewritten.

[0254] In this disclosure, the link direction, downlink (DL), uplink (UL), UL, and DL can also be rewritten to each other.

[0255] In this disclosure, pools, sets, groups, and lists can be interchanged.

[0256] In this disclosure, common beam, common TCI, common TCI state, unified TCI, unified TCI state, TCI state applicable in DL and UL, TCI state applied in multiple channels / RS, TCI state applicable in multiple channels / RS, and PL-RS can also be rewritten to each other.

[0257] In this disclosure, multiple TCI states set via RRC, multiple TCI states activated via MAC CE, pools, TCI state pools, activated TCI state pools, common TCI state pools, joint TCI state pools, independent TCI state pools, common TCI state pools for UL, common TCI state pools for DL, common TCI state pools set / activated via RRC / MAC CE, and TCI state information can also be mutually modified.

[0258] In this disclosure, the following information may be overwritten: CC list, serving cell list, CC list in cell group configuration (CellGroupConfig), applicable list, simultaneous TCI update list / second simultaneous TCI update list, simultaneousTCI-UpdateList1-r16 / simultaneousTCI-UpdateList2-r16, simultaneous TCI cell list, simultaneousTCI-CellList, simultaneous spatial update list / second simultaneous spatial update list, simultaneousSpatial-UpdatedList1-r16 / simultaneousSpatial-UpdatedList2-r16, configured CC, configured list, BWP / CC in configured list, all BWP / CC in configured list, CC indicated by activation command, indicated CC, CC receiving MACCE, and information of multiple cells indicating updates for at least one of TCI status and spatial relationships.

[0259] In this disclosure, BFR, BFR settings, BFD-RS, BFD-RS sets, BFD-RS settings, RLM-RS, RLM-RS sets, and RLM-RS settings can be mutually modified. In this disclosure, per-cell BFR, cell-specific BFR, and Rel.15 / 16 BFR can also be mutually modified. In this disclosure, per-TRP BFR, TRP-specific BFR, and Rel.17 / Rel.17 and beyond BFR can also be mutually modified.

[0260] In this disclosure, BFD-RS, RLM-RS, NCBI-RS, Detection RS, and Monitoring RS can also be rewritten to each other.

[0261] (Wireless communication method)

[0262] The following example illustrates the application of wireless communication methods to BFD-RS. However, BFD-RS can also be rewritten as RLM-RS, and wireless communication methods can also be applied to RLM-RS.

[0263] Two sets of BFD-RS can also be configured. Two BFD-RS sets can also be associated with two separate TRPs. Two BFD-RS sets can also be configured via RRC. Each BFD-RS set can contain more than one BFD-RS. When multiple CORESETs are configured for a TRP, multiple BFD-RSs within the BFD-RS set corresponding to that TRP can be associated with each of these multiple CORESETs (and can also be QCLed). When multiple CORESETs are configured for a TRP, one BFD-RS within a BFD-RS set can also be associated with these multiple CORESETs (and can also be QCLed).

[0264] One or two TCI states can be set / activated for a single CORESET. Two BFD-RS can also be associated with a single CORESET. Two BFD-RS can also be associated with two TCI states of a single CORESET, respectively.

[0265] The UE can also receive a first setting of a CORESET with multiple TCI states, a second setting of one or more first RSs used in BFD or RLM, and a MAC CE. The UE can also determine one or more second RSs to use in the BFD or RLM based on the first setting, the second setting, and the MAC CE (or update one or more first RSs to one or more second RSs). The one or more first reference signals can also be associated with the multiple TCI states respectively. The MAC CE can be a UE-specific PDCCH TCI state indication MAC CE, or a new MAC CE.

[0266] Since the two TCI states within the CORESET are updated via MAC CE, it is beneficial for the UE to support MAC CE to update BFD-RS / RLM-RS explicitly or implicitly so that BFD-RS / RLM-RS contains the RS of both of the two TCI states of the CORESET.

[0267] <First Embodiment>

[0268] When BFD-RS is set via RRC and QCL is performed with CORESET i, and one or more TCI states (one or two TCI states) set for CORESET i are updated via MAC CE (or one or more TCI states associated with CORESET i are updated via MAC CE), BFD-RS can also be automatically updated to P-CSI-RS or SSB set within one or more updated TCI states of CORESET i (or associated with RS within one or more updated TCI states of CORESET i). If there are two RSs within each updated TCI state, P-CSI-RS or SSB can also correspond to RSs with QCL type D.

[0269] In this case, a rule can also be specified to select which of the multiple CORESETs to apply to the BFD-RS decision (CORESET selection rule). The applied CORESET can also be determined based on at least one of the following: the period of the RS within the CORESET's TCI state (e.g., the CORESET corresponding to the smallest or largest period is selected), and the CORESET ID (e.g., the CORESET with the smallest or largest CORESET ID is selected). A CORESET with multiple TCI states set can also be selected preferentially. In this case, the reliability of the PDCCH SFN can be improved. A CORESET with multiple TCI states set can also be selected preferentially (a CORESET with TCI states set may not be selected preferentially).

[0270] If the TCI state (or common TCI state) of a CORESET (CORESET i) selected according to the CORESET selection rules is updated via MAC CE, the UE can also use the RS in the TCI state of the selected CORESET as the BFD-RS (or update the BFD-RS to the RS in the associated TCI state).

[0271] If the TCI state (or common TCI state) of any CORESET in multiple CORESETs is updated via MAC CE, the UE can also follow the CORESET selection rules to use the RS in the TCI state of one CORESET (CORESETi) as the BFD-RS (or update the RS in the associated TCI state).

[0272] The BFD-RS update can be applied in both the cell-specific BFD-RS settings (per cell, Rel. 15 / 16) and the TRP-specific BFD-RS settings (per TRP, Rel. 17 and later), as well as in both the BFR for each TRP based on a single DCI and the BFR for each TRP based on multiple DCIs.

[0273] Figure 2This example illustrates the BFD-RS settings for each cell. In this example, CORESET#1 is set for cell #1, and TCI states #A and #B are indicated for CORESET#1. Further, BFD-RS#a, which is a QCL (Quality Class Required) for TCI state #A of CORESET#1, and BFD-RS#b, which is a QCL (Quality Class Required) for TCI state #B of CORESET#1, are set. Therefore, the BFD-RS settings for cell #1 are BFD-RS#a and #b.

[0274] When the TCI state #A of cell #1's CORESET #1 is updated to TCI state #C via MAC CE, the BFD-RS corresponding to the TCI state #A of CORESET #1 is automatically updated to BFD-RS#c, which is the RS included (associated) in the updated TCI state #C. At this time, BFD-RS#b, which becomes QCL with the TCI state #B of CORESET #1, is not updated; the BFD-RS for cell #1 are BFD-RS#c and #b.

[0275] Figure 3 Here is another example of BFD-RS settings for each cell. In this example, CORESET#1 is set for cell #1, and TCI states #A and #B are indicated for CORESET#1. Further, BFD-RS#a, which is QCL with TCI state #A of CORESET#1, and BFD-RS#b, which is QCL with TCI state #B of CORESET#1, are set. In this case, the BFD-RS for cell #1 are BFD-RS#a and #b.

[0276] When the TCI state #A of CORESET #1 in cell #1 is updated to TCI state #B via MAC CE, the BFD-RS corresponding to the TCI state #A of CORESET #1 is automatically updated to the RS (BFD-RS#b) contained in (associated with) TCI state #B. At this time, the BFD-RS#b that forms a QCL with the TCI state #B of CORESET #1 is not updated; the BFD-RS for cell #1 is BFD-RS#b. Thus, a BFD-RS can also be updated to a single BFD-RS.

[0277] Figure 4An example of BFD-RS settings for each TRP is shown. This BFD-RS setting can also be applied to both single-DCI-based multi-TRPs and multi-DCI-based multi-TRPs. In this example, CORESET#1 is set for TRP#1, CORESET#2 is set for TRP#2, TCI state #A is indicated for CORESET#1, and TCI states #B and #C are indicated for CORESET#2. TRP#2 can also be associated with a new ID or CORESET pool index = 1. Further, a BFD-RS set #1 is set containing BFD-RS#a that becomes a QCL with TCI state #A of CORESET#1, and a BFD-RS set #2 is set containing BFD-RS#b that becomes a QCL with TCI state #B of CORESET#2, and BFD-RS#c that becomes a QCL with TCI state #C of CORESET#2. BFD-RS set #1 can also be associated with TRP#1. BFD-RS set #2 can also be associated with TRP #2. In this case, BFD-RS are BFD-RS#a, #b, and #c.

[0278] When CORESET#1's TCI state #A is updated to TCI state #D via MAC CE, the BFD-RS corresponding to that CORESET#1 is automatically updated to the RS (associated with) TCI state #D, i.e., BFD-RS#d. When CORESET#2's TCI state #C is updated to TCI state #E via MAC CE, the BFD-RS corresponding to that CORESET#2's TCI state #C is automatically updated to the RS (associated with) TCI state #E, i.e., BFD-RS#e. At this point, the BFD-RS for TRP#1 and #2 are BFD-RS#d, #b, and #e. The number of BFD-RS can also exceed the Rel.15 / 16 limit of 2.

[0279] In the case where one or more TCI states of CORESET i are updated via MAC CE, the updated TCI states can also belong to the same TRP as the original (before update) TCI states (or can be associated with the same new ID, the same CORESET pool index, or the same TRP associated ID).

[0280] If the number of BFD-RS in each BFD-RS set is limited, and the TCI states of multiple CORESETs corresponding to the same BFD-RS in the same BFD-RS set are updated, the multiple TCI states updated for these CORESETs can also be any one of the following options 1-1 and 1-2.

[0281] [Option 1-1]

[0282] These multiple TCI states have the same TCI state.

[0283] Figure 5 Another example of BFD-RS settings for each TRP is shown. This BFD-RS setting can also be applied to both single-DCI-based multi-TRPs and multi-DCI-based multi-TRPs. In this example, CORESET#1 is set for TRP#1, CORESET#2 is set for TRP#2, TCI state #A is indicated for CORESET#1, and TCI states #B and #C are indicated for CORESET#2. TRP#2 can also be associated with a new ID or CORESET pool index = 1. Further, BFD-RS set #1, containing BFD-RS#a that becomes a QCL with TCI state #A of CORESET#1, is set; and BFD-RS set #2, containing BFD-RS#b that becomes a QCL with TCI states #B and #C of CORESET#2, is set. BFD-RS set #1 can also be associated with TRP#1. BFD-RS set #2 can also be associated with TRP#2. At this point, BFD-RS are BFD-RS#a and #b.

[0284] Figure 5 In the example of option 1-1, the TCI states #B and #C of CORESET#2 are updated to TCI state #E via MAC CE. In this case, the BFD-RS corresponding to the TCI states #B and #C of CORESET#2 are automatically updated to the RS contained (associated) in TCI state #E, namely BFD-RS#e. At this time, the BFD-RS for TRP#1 and #2 are BFD-RS#a in BFD-RS set #1 and BFD-RS#e in BFD-RS set #2.

[0285] [Options 1-2]

[0286] These multiple TCI states are associated with the same BFD-RS / become QCLs.

[0287] Figure 5In the example of option 1-2, the TCI state #B of CORESET#2 is updated to TCI state #E via MAC CE, and the TCI state #C of CORESET#2 is updated to TCI state #F via MAC CE. In this case, the BFD-RS corresponding to the TCI states #B and #C of CORESET#2 is automatically updated to the same RS associated with the TCI states #B and #C of CORESET#2 (the same RS that forms the QCL for these CORESETs), namely BFD-RS#e. At this time, the BFD-RS for TRP#1 and #2 are BFD-RS#a in BFD-RS set #1 and BFD-RS#e in BFD-RS set #2.

[0288] According to this implementation, even if the TCI state of the CORESET that is a QCL with BFD-RS is updated, the UE can still appropriately determine BFD-RS.

[0289] <Second Implementation>

[0290] A new MAC CE can also be specified for BFD-RS updates. This MAC CE can also have a new logical channel ID (LCID). The new MAC CE can also be applied in cases where it differs from the MAC CE indicated by the TCI state in the UE-specific PDCCH.

[0291] The new MAC CE can also follow at least one of the following options 2-1 to 2-7.

[0292] For each cell’s BFR, the new MAC CE can also follow any of the following options 2-1 to 2-3.

[0293] [Option 2-1]

[0294] The MAC CE contains one or two BFD-RS fields, a serving cell ID field, and a BWP ID field. The MAC CE is applied in the specified serving cell / BWP.

[0295] Figure 6A The following is an example of the MAC CE involved in option 2-1. This example assumes one BFD-RS per TRP. The MAC CE includes the T field, the serving cell ID field, the BWP ID field, the first R (reserved bit) field, the first BFD-RS ID (BFD-RS ID1) field, the first R field, and the second BFD-RS ID (BFD-RS ID2) field.

[0296] The T field can also indicate whether a second BFD-RS field exists.

[0297] Each BFD-RS field may also be accompanied by a flag to identify whether it represents a CSI-RS resource ID or an SSB ID.

[0298] [Option 2-2]

[0299] The MAC CE contains one or two BFD-RS fields, a serving cell ID field, and a BWP ID field. The CC list is set via RRC, and the MAC CE is applied to multiple CCs within the CC list containing the indicated serving cell. This means that the MAC CE performs simultaneous BFD-RS updates for multiple CCs, and multiple CCs use the same BFD-RS.

[0300] [Options 2-3]

[0301] A MAC CE contains more than one set. Each set contains one or two BFD-RS fields, a serving cell ID field, and a BWP ID field. More than one set represents different serving cell IDs. This means that the MAC CE can update different BFD-RS for multiple CCs.

[0302] For each TRP's BFR, the new MAC CE can also follow any of the following options 2-4 to 2-6.

[0303] [Options 2-4]

[0304] The MAC CE contains one or two BFD-RS fields, a serving cell ID field, and a BWP ID field for each TRP. The MAC CE may or may not include fields for the TRP-ID / New ID / CORESET pool index associated with the TRP. The MAC CE is applied to the indicated serving cell / BWP.

[0305] Figure 6B An example of the MAC CE involved in options 2-4 is shown. This example assumes one BFD-RS per TRP. The MAC CE includes the T field, Serving Cell ID field, BWP ID field, A field, First BFD-RS ID field, R field, and Second BFD-RS ID field.

[0306] The T field can indicate whether there is one BFD-RS field (T=0) or two BFD-RS fields (T=1), or whether the MAC CE is used by one TRP (T=0) or two MAC CEs (T=1).

[0307] Each BFD-RS field may also be accompanied by a flag to identify whether it represents a CSI-RS resource ID or an SSB ID.

[0308] Field A can also represent information related to the TRP of the BFD-RS when there is a BFD-RS field (T=0) in the MAC CE. For example, if there is only one BFD-RS field in the MAC CE, field A can also represent the TRP-ID / new ID / CORESET pool index corresponding to that BFD-RS field.

[0309] [Options 2-5]

[0310] The MAC CE contains one or two BFD-RS fields, a serving cell ID field, and a BWP ID field for each TRP. The MAC CE may or may not include fields for the TRP-ID / new ID / CORESET pool index associated with the TRP. The CC list is set via RRC, and the MAC CE is applied to multiple CCs within the CC list containing the indicated serving cell. This means that the MAC CE performs simultaneous BFD-RS updates for multiple CCs, and multiple CCs use the same BFD-RS.

[0311] In this case, all CCs set in the CC list can also have their BFRs set for each TRP.

[0312] [Options 2-6]

[0313] A MAC CE contains more than one set. Each set contains one or two BFD-RS fields, a serving cell ID field, and a BWP ID field for each TRP. Each set may or may not contain fields for the TRP-ID / new ID / CORESET pool index associated with the TRP. More than one set indicates different serving cell IDs. This means that the MAC CE can update different BFD-RS for multiple CCs with BFRs set for each TRP.

[0314] The new MAC CE can also follow options 2-7 below.

[0315] [Options 2-7]

[0316] The MAC CE can contain either a BFD-RS for cells with BFR configured for each cell, or a BFD-RS for cells with BFR configured for each TRP. The MAC CE can also be a combination of options 2-3 and 2-6.

[0317] If the MAC CE for a cell with a BFR set for each TRP contains a field for the TRP-ID / new ID / CORESET pool index associated with the TRP, then it becomes clear which TRP in which cell each BFD-RS field is applied. This means that the MAC CE can update the BFD-RS for only one TRP for that cell, and can maintain the BFD-RS for other TRPs in that cell.

[0318] If the MAC CE for a cell with a BFR set for each TRP does not contain a field for the TRP-ID / new ID / CORESET pool index associated with the TRP, then this means that the MAC CE can update the BFD-RS for two TRPs simultaneously for that cell. The MAC CE can also follow options 2-7-1 and 2-7-2 below.

[0319] [[Options 2-7-1]]

[0320] Within the MAC CE for each cell / BWP, a new flag may also be needed to indicate whether the MAC CE is for the BFD-RS of each cell or for the BFD-RS of each TRP (two sets with BFD-RS fields).

[0321] [[Option 2-7-2]]

[0322] A new flag may not be required within the MAC CE for each cell / BWP. Whether the MAC CE is used for the BFD-RS of each cell or the BFD-RS of each TRP can depend on the BFR settings for the cell, or it can be implicitly indicated by the RRC used for BFR settings.

[0323] Variations

[0324] BFD-RS can also be set / notified for each CORESET.

[0325] The CORESET selection rule in the first embodiment can also be applied. When a CORESET is selected in accordance with the CORESET selection rule, the BFD-RS for the selected CORESET (the BFD-RS notified to the selected CORESET via MACCE) is used for BFD.

[0326] Figure 7This illustrates an example of a MAC CE involved in a variation of the second embodiment. The MAC CE notifies one or two BFD-RSs of the CORESET. The MAC CE includes: a serving cell ID field, a CORESET ID field, a first BFD-RS ID (BFD-RS ID1) field, a first R field, an R field, and a second BFD-RS ID (BFD-RS ID2) field.

[0327] The Serving Cell ID field indicates the serving cell to which the MAC CE is applied. The CORESET ID field indicates the CORESET to which the MAC CE is applied. The 1st BFD-RS ID field indicates the 1st BFD-RS. The 1st BFD-RS ID field may also be accompanied by a flag indicating whether the 1st BFD-RS is a CSI-RS resource ID or an SSB ID. The 2nd BFD-RS ID field indicates the 2nd BFD-RS. The 2nd BFD-RS ID field may also be accompanied by a flag indicating whether the 1st BFD-RS is a CSI-RS resource ID or an SSB ID.

[0328] According to this implementation, the UE can properly determine the BFD RS even when the BFD RS is not explicitly set.

[0329] <Third Implementation>

[0330] If BFD-RS / RLM-RS is not set, the UE follows the rule (RS selection rule) and selects BFD-RS / RLM-RS.

[0331] Regarding the RS selection rule, it can also follow the CORESET selection rule in the first embodiment, selecting the CORESET and choosing the RS within one or more TCI states set for that CORESET as BFD-RS / RLM-RS. Here, if there are QCL type A RS and QCL type D RS in each TCI state, the UE can also select the QCL type DRS as BFD-RS / RLM-RS.

[0332] Regarding the RS selection rule, it is also possible to select RSs within one or more TCI states set for all CORESETs as candidates for BFD-RS / RLM-RS, follow the CORESET selection rule in the first embodiment, select a CORESET, and select a specific number of RSs from the RSs within the TCI states set for that CORESET as BFD-RS / RLM-RS.

[0333] If multiple TCI states are set for each of at least one CORESET and BFD-RS / RLM-RS is not set, the UE can also select BFD-RS / RLM-RS by following the RS selection rules.

[0334] According to this implementation, the UE can properly determine the BFD RS even when the BFD RS is not explicitly set.

[0335] <Fourth Implementation>

[0336] Alternatively, the higher-level parameters (RRC information elements) / UE capabilities corresponding to at least one function (feature) in the first to third embodiments can be specified. UE capabilities can also indicate support for that function.

[0337] UEs that have been configured with the corresponding higher-layer parameters for this function can also perform this function. Alternatively, it can be specified that "UEs that have not been configured with the corresponding higher-layer parameters for this function will not perform this function".

[0338] UEs that report indicating their ability to support this function can also perform this function. Alternatively, it can be specified that "UEs that do not report indicating their ability to support this function will not perform this function."

[0339] The UE can perform this function if it reports a UE capability indicating support for the function and the corresponding higher-layer parameters are set. Alternatively, it can be specified that "the UE will not perform this function if the UE does not report a UE capability indicating support for the function or if the corresponding higher-layer parameters are not set."

[0340] UE capabilities can also indicate whether the UE supports the function.

[0341] UE capabilities can also indicate whether the PDCCH repeat / PDCCH SFN scheme is supported.

[0342] UE capabilities can also indicate whether automatic BFD-RS updates for a serving cell are supported for at least one of Rel.15 / 16 BFR (BFR per cell) and Rel.17 and later BFRs (e.g., BFR per TRP), based on TCI state updates for CORESET via MAC CE.

[0343] UE capabilities can also indicate whether automatic BFD-RS updates for multiple serving cells are supported simultaneously, based on TCI status updates for CORESET via MAC CE, for at least one of Rel.15 / 16 BFR (BFR per cell) and Rel.17 and later BFRs (e.g., BFR per TRP).

[0344] UE capabilities can also indicate whether, for at least one of Rel.15 / 16 BFR (BFR per cell) and Rel.17 and later BFRs (e.g., BFR per TRP), BFD-RS updates for a serving cell based on the new MAC CE are supported.

[0345] UE capabilities can also indicate whether, for at least one of Rel.15 / 16 BFR (BFR per cell) and Rel.17 and later BFRs (e.g., BFR per TRP), simultaneous BFD-RS updates for multiple serving cells based on the new MAC CE are supported.

[0346] According to this implementation, the UE maintains compatibility with existing specifications and is able to achieve the functions described above.

[0347] (Wireless Communication System)

[0348] The structure of a wireless communication system according to one embodiment of this disclosure will be described below. In this wireless communication system, communication is performed using any one or a combination of the wireless communication methods according to the above embodiments of this disclosure.

[0349] Figure 8 This is a diagram illustrating an example of the schematic structure of a wireless communication system according to one embodiment. The wireless communication system 1 may also be a system that uses Long Term Evolution (LTE) or 5th generation mobile communication system New Radio (5G NR) as standardized by the Third Generation Partnership Project (3GPP).

[0350] Furthermore, the wireless communication system 1 can also support dual connectivity between multiple radio access technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC can also 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.

[0351] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (MN), and the NR base station (gNB) is the 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.

[0352] Wireless communication system 1 can also support dual connectivity between multiple base stations within the same RAT (e.g., MN and SN are dual connectivity of NR base stations (gNB) (NR-NR Dual Connectivity (NN-DC))).

[0353] The wireless communication system 1 may also include a base station 11 forming a macro cell C1 with a relatively wide coverage area, and a base station 12 (12a-12c) configured within the macro cell C1 and forming a small cell C2 narrower than the macro cell C1. The user terminal 20 may also be located within at least one cell. The configuration and number of each cell and the user terminal 20 are not limited to the arrangement shown in the figure. Hereinafter, without distinguishing between base stations 11 and 12, they will be collectively referred to as base station 10.

[0354] User terminal 20 may also connect to at least one of multiple base stations 10. User terminal 20 may also utilize at least one of carrier aggregation (CA) using multiple component carriers (CC) and dual connectivity (DC).

[0355] Each CC can also be included in at least one of the first frequency band (Frequency Range 1 (FR1)) and the second frequency band (Frequency Range 2 (FR2)). Macro cell C1 can also be included in FR1, and small cell C2 can also be included in FR2. For example, FR1 can also be a frequency band below 6 GHz (sub-6 GHz), and FR2 can also be a frequency band above 24 GHz (above-24 GHz). Furthermore, the frequency bands and definitions of FR1 and FR2 are not limited to these; for example, FR1 can also correspond to a frequency band higher than FR2.

[0356] In addition, user terminal 20 can also use at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD) to communicate in each CC.

[0357] Multiple base stations 10 can also be connected via wired (e.g., fiber optic cable based on the Common Public Radio Interface (CPRI), X2 interface, etc.) or wireless (e.g., NR communication). For example, when NR communication between base stations 11 and 12 is used as a backhaul, base station 11, which is equivalent to a host station, can also be referred to as an Integrated Access Backhaul (IAB) donor, and base station 12, which is equivalent to a relay station, can also be referred to as an IAB node.

[0358] Base station 10 may also be connected to core network 30 via other base stations 10 or directly. Core network 30 may include, for example, at least one of Evolved Packet Core (EPC), 5G Core Network (5GCN), Next Generation Core (NGC), etc.

[0359] User terminal 20 can also be a terminal that supports at least one of the following communication methods: LTE, LTE-A, 5G, etc.

[0360] In wireless communication system 1, wireless access methods based on Orthogonal Frequency Division Multiplexing (OFDM) can also be used. For example, in at least one of the downlink (DL) and uplink (UL) links, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), and Single Carrier Frequency Division Multiple Access (SC-FDMA) can also be used.

[0361] Wireless access methods can also be referred to as waveforms. In addition, in wireless communication system 1, other wireless access methods (e.g., other single-carrier transmission methods, other multi-carrier transmission methods) can also be applied in the wireless access methods of UL and DL.

[0362] As a downlink channel, the wireless communication system 1 can also use downlink shared channels (Physical Downlink Shared Channel (PDSCH)), broadcast channels (Physical Broadcast Channel (PBCH)), downlink control channels (Physical Downlink Control Channel (PDCCH)) and so on, which are shared by each user terminal 20.

[0363] In addition, as uplink channels, the wireless communication system 1 may also use uplink shared channels (Physical Uplink Shared Channel (PUSCH)), uplink control channels (Physical Uplink Control Channel (PUCCH)), random access channels (Physical Random Access Channel (PRACH)) and so on, which are shared by each user terminal 20.

[0364] User data, high-level control information, and System Information Blocks (SIBs) are transmitted via the PDSCH. User data and high-level control information can also be transmitted via the PUSCH. Furthermore, the Master Information Block (MIB) can also be transmitted via the PBCH.

[0365] Lower-layer control information can also be transmitted via PDCCH. Lower-layer control information may include, for example, downlink control information (DCI), which includes scheduling information for at least one of PDSCH and PUSCH.

[0366] Additionally, the DCI for scheduling PDSCH can also be called DL allocation, DL DCI, etc., and the DCI for scheduling PUSCH can also be called UL authorization, UL DCI, etc. Furthermore, PDSCH can be rewritten as DL data, and PUSCH can be rewritten as UL data.

[0367] In PDCCH detection, a Control Resource Set (CORESET) and a search space can be utilized. A CORESET corresponds to the resources used to search for DCIs. The search space corresponds to the search area and search method for PDCCH candidates. A CORESET can also be associated with one or more search spaces. The UE can also monitor CORESETs associated with a specific search space based on search space settings.

[0368] A search space can also correspond to a PDCCH candidate corresponding to one or more aggregation levels. One or more search spaces can also be referred to as a search space set. In addition, the terms "search space", "search space set", "search space setting", "search space set setting", "CORESET", "CORESET setting" etc. disclosed herein can be rewritten interchangeably.

[0369] Uplink control information (UCI) including at least one of Channel State Information (CSI), delivery confirmation information (e.g., also known as Hybrid Automatic Repeat Request Acknowledgment (HARQ-ACK), ACK / NACK, etc.), and Scheduling Request (SR) can also be transmitted via PUCCH. Random access preambles used for establishing a connection with the cell can also be transmitted via PRACH.

[0370] Additionally, in this disclosure, downlink, uplink, etc., may be described without the word "link". Furthermore, it may be described without "physical" at the beginning of various channels.

[0371] In wireless communication system 1, synchronization signals (SS) and downlink reference signals (DL-RS) can also be transmitted. As DL-RS, wireless communication system 1 can also transmit cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), demodulation reference signals (DMRS), positioning reference signals (PRS), phase tracking reference signals (PTRS), etc.

[0372] Synchronization signals can be, for example, at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). A signal block containing SS (PSS, SSS) and PBCH (and DMRS for PBCH) can also be called an SS / PBCH block, SS block (SSB), etc. Furthermore, SS, SSB, etc., can also be called reference signals.

[0373] Furthermore, in the wireless communication system 1, the uplink reference signal (UL-RS) can also transmit measurement reference signals (sounding reference signals (SRS)) and demodulation reference signals (DMRS). Additionally, the DMRS can also be referred to as a user terminal-specific reference signal (UE-specific reference signal).

[0374] (Base station)

[0375] Figure 9 This diagram illustrates an example of the structure of a base station according to one embodiment. The base station 10 includes a control unit 110, a transmit / receive unit 120, a transmit / receive antenna 130, and a transmission path interface (transmission line interface) 140. Alternatively, the control unit 110, the transmit / receive unit 120, the transmit / receive antenna 130, and the transmission path interface 140 may each be provided in more than one manner.

[0376] Furthermore, while this example primarily illustrates the functional blocks of the characteristic portions of this embodiment, it is also conceivable that the base station 10 may also possess other functional blocks required for wireless communication. Some of the processing of each unit described below may also be omitted.

[0377] The control unit 110 performs overall control of the base station 10. The control unit 110 can be composed of a controller, control circuit, etc., which are described based on common knowledge in the art to which this disclosure pertains.

[0378] The control unit 110 can also control signal generation and scheduling (e.g., resource allocation, mapping). The control unit 110 can also control transmission, reception, and measurement using the transmit / receive unit 120, transmit / receive antenna 130, and transmission path interface 140. The control unit 110 can also generate data, control information, sequences, etc., to be transmitted as signals and forward them to the transmit / receive unit 120. The control unit 110 can also perform call processing (setting, releasing, etc.) of the communication channel, status management of the base station 10, and management of wireless resources.

[0379] The transmitting / receiving unit 120 may also include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may also include a transmitting processing unit 1211 and a receiving processing unit 1212. The transmitting / receiving unit 120 can be composed of transmitters / receivers, RF circuits, baseband circuits, filters, phase shifters, measurement circuits, transmitting / receiving circuits, etc., as described based on common knowledge in the art to which this disclosure pertains.

[0380] The transmitting and receiving unit 120 can be configured as a single integrated transmitting and receiving unit, or it can be composed of a transmitting unit and a receiving unit. The transmitting unit can also be composed of a transmitting processing unit 1211 and an RF unit 122. The receiving unit can also be composed of a receiving processing unit 1212, an RF unit 122, and a measurement unit 123.

[0381] The transmitting and receiving antenna 130 can be constructed from an antenna, such as an array antenna, as described based on common knowledge in the art to which this disclosure pertains.

[0382] The transmitting / receiving unit 120 can also transmit the aforementioned downlink channel, synchronization signal, downlink reference signal, etc. The transmitting / receiving unit 120 can also receive the aforementioned uplink channel, uplink reference signal, etc.

[0383] The transmitting and receiving unit 120 may also use digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc., to form at least one of the transmitting beam and the receiving beam.

[0384] The transmitting and receiving unit 120 (transmitting processing unit 1211) may, for example, perform processing at the Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer (e.g., RLC retransmission control), and Medium Access Control (MAC) layer (e.g., HARQ retransmission control) on the data and control information obtained from the control unit 110, and generate a bit string to be transmitted.

[0385] The transmitting and receiving unit 120 (transmitting processing unit 1211) can also perform transmission processing such as channel coding (which may also include error correction coding), modulation, mapping, filter processing, Discrete Fourier Transform (DFT) processing (as needed), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output the baseband signal.

[0386] The transmitting and receiving unit 120 (RF unit 122) can also perform modulation, filtering, amplification, etc. on the baseband signal to the wireless frequency band, and transmit the wireless frequency band signal through the transmitting and receiving antenna 130.

[0387] On the other hand, the transmitting and receiving unit 120 (RF unit 122) can also amplify, filter, demodulate, etc., the signals of the wireless frequency band received by the transmitting and receiving antenna 130.

[0388] The transmitting and receiving unit 120 (receiving and processing unit 1212) can also perform receiving and processing on the acquired baseband signal, including analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (as needed), filter processing, demapping, demodulation, decoding (which may also include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing, to acquire user data.

[0389] The transmitting / receiving unit 120 (measurement unit 123) can also perform measurements related to the received signal. For example, the measurement unit 123 can also perform radio resource management (RRM) measurements, channel state information (CSI) measurements, etc., based on the received signal. The measurement unit 123 can also 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 can also be output to the control unit 110.

[0390] The transmission path interface 140 can also transmit and receive signals (backhaul signaling) between the device included in the core network 30 and other base stations 10, and can also acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0391] In addition, the transmitting unit and receiving unit of the base station 10 in this disclosure may also be composed of at least one of a transmitting / receiving unit 120, a transmitting / receiving antenna 130, and a transmission path interface 140.

[0392] The transmit / receive unit 120 may also transmit a first setting of a control resource set (CORESET) having multiple transmission configuration indication (TCI) states, and a second setting of one or more first reference signals for beam failure detection (BFD) or radio link monitoring (RLM). The control unit 110 may also determine one or more second reference signals used in the BFD or the RLM. The one or more first reference signals may also be associated with the multiple TCI states respectively. The transmit / receive unit 120 may also transmit a medium access control-control element (MAC CE) associated with the one or more second reference signals.

[0393] (User terminal)

[0394] Figure 10 This diagram illustrates an example of the structure of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transmitting / receiving unit 220, and a transmitting / receiving antenna 230. Alternatively, the control unit 210, the transmitting / receiving unit 220, and the transmitting / receiving antenna 230 may each be provided as one or more.

[0395] Furthermore, while this example primarily illustrates the functional blocks of the characteristic portions of this embodiment, it is also conceivable that the user terminal 20 may also possess other functional blocks required for wireless communication. Some of the processing of each unit described below may also be omitted.

[0396] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be composed of a controller, control circuit, etc., which are described based on common knowledge in the technical field to which this disclosure pertains.

[0397] The control unit 210 can also control signal generation, mapping, etc. The control unit 210 can also control transmission, reception, measurement, etc., using the transmission / reception unit 220 and the transmission / reception antenna 230. The control unit 210 can also generate data, control information, sequences, etc., to be transmitted as signals and forward them to the transmission / reception unit 220.

[0398] The transmitting / receiving unit 220 may also include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may also include a transmitting processing unit 2211 and a receiving processing unit 2212. The transmitting / receiving unit 220 may be composed of transmitters / receivers, RF circuits, baseband circuits, filters, phase shifters, measurement circuits, transmitting / receiving circuits, etc., as described based on common knowledge in the art to which this disclosure pertains.

[0399] The transmitting and receiving unit 220 can be configured as a single integrated transmitting and receiving unit, or it can be composed of a transmitting unit and a receiving unit. The transmitting unit can also be composed of a transmitting processing unit 2211 and an RF unit 222. The receiving unit can also be composed of a receiving processing unit 2212, an RF unit 222, and a measurement unit 223.

[0400] The transmitting and receiving antenna 230 can be constructed from an antenna, such as an array antenna, as described based on common knowledge in the art to which this disclosure pertains.

[0401] The transmitting / receiving unit 220 can also receive the downlink channel, synchronization signal, downlink reference signal, etc., mentioned above. The transmitting / receiving unit 220 can also transmit the uplink channel, uplink reference signal, etc., mentioned above.

[0402] The transmitting and receiving unit 220 may also use digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc., to form at least one of the transmitting beam and the receiving beam.

[0403] The transmitting and receiving unit 220 (transmitting processing unit 2211) may, for example, perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control) on the data and control information obtained from the control unit 210, and generate the bit string to be transmitted.

[0404] The transmitting and receiving unit 220 (transmitting processing unit 2211) can also perform channel coding (which may include error correction coding), modulation, mapping, filter processing, DFT processing (as needed), IFFT processing, precoding, digital-to-analog conversion and other transmission processing on the bit string to be transmitted, and output the baseband signal.

[0405] Furthermore, the application of DFT processing can be based on the transform precoding settings. For a specific channel (e.g., PUSCH), if transform precoding is enabled, the transmit / receive unit 220 (transmit processing unit 2211) can perform DFT processing as described above for transmitting the channel using the DFT-s-OFDM waveform. Otherwise, the transmit / receive unit 220 (transmit processing unit 2211) can perform DFT processing as described above without performing DFT processing.

[0406] The transmitting and receiving unit 220 (RF unit 222) can also perform modulation, filtering, amplification, etc. on the baseband signal to the wireless frequency band, and transmit the wireless frequency band signal through the transmitting and receiving antenna 230.

[0407] On the other hand, the transmitting and receiving unit 220 (RF unit 222) can also amplify, filter, and demodulate the baseband signal for the wireless frequency band signal received by the transmitting and receiving antenna 230.

[0408] The transmitting and receiving unit 220 (receiving and processing unit 2212) can also perform receiving and processing on the acquired baseband signal, such as analog-to-digital conversion, FFT processing, IDFT processing (as needed), filter processing, demapping, demodulation, decoding (which may also include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing, to acquire user data.

[0409] The transmitting / receiving unit 220 (measurement unit 223) can also perform measurements related to the received signal. For example, the measurement unit 223 can also perform RRM measurements, CSI measurements, etc., based on the received signal. The measurement unit 223 can also 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 can also be output to the control unit 210.

[0410] In addition, the transmitting unit and receiving unit of the user terminal 20 in this disclosure can also be configured by at least one of the transmitting / receiving unit 220, the transmitting / receiving antenna 230 and the transmission path interface 240.

[0411] The transmit / receive unit 220 can also receive a first setting of a control resource set (CORESET) having multiple transmission configuration indication (TCI) states, and a second setting of one or more first reference signals used for beam failure detection (BFD) or radio link monitoring (RLM), and a medium access control-control element (MAC CE). The control unit 210 can also determine one or more second reference signals to be used in the BFD or RLM based on the first setting, the second setting, and the MAC CE. The one or more first reference signals can also be associated with the multiple TCI states respectively.

[0412] The MAC CE can also represent one or more TCI states. The one or more second reference signals can also include a third reference signal within the one or more TCI states (first embodiment).

[0413] The first setting can also represent multiple CORESETs. The multiple CORESETs can also include the CORESET. The control unit 210 can also select the CORESET from the multiple CORESETs (first embodiment).

[0414] The MAC CE can also represent one or more second reference signals (second embodiment).

[0415] (Hardware Structure)

[0416] Furthermore, the block diagrams used in the description of the above embodiments illustrate functional units. These functional blocks (structural units) are implemented through any combination of at least one of hardware and software. Moreover, the implementation method of each functional block is not particularly limited. That is, each functional block can be implemented using a single device that is physically or logically combined, or it can be implemented by directly or indirectly (e.g., using wired, wireless, etc.) connecting two or more physically or logically separate devices. A functional block can also be implemented by combining the aforementioned single device or multiple devices with software.

[0417] Here, the functions include judgment, decision, determination, calculation, calculation, processing, export, investigation, search, confirmation, receiving, sending, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, regard as, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning, but are not limited to these. For example, a functional block (structural unit) that implements the sending function can also be called a transmitting unit, transmitter, etc. As described above, the implementation method is not particularly limited.

[0418] For example, in one embodiment of this disclosure, the base station, user terminal, etc., can also function as a computer for processing the wireless communication method of this disclosure. Figure 11 This diagram illustrates an example of the hardware structure of a base station and a user terminal according to one embodiment. The base station 10 and the user terminal 20 described above can also be physically configured as a computer device including a processor 1001, a memory 1002, a storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0419] Furthermore, in this disclosure, terms such as apparatus, circuit, device, section, and unit can be interchanged. The hardware structure of base station 10 and user terminal 20 can be configured to include one or more of the apparatuses shown in the figures, or it can be configured not to include any of the apparatuses.

[0420] For example, only one processor 1001 is shown, but there can be multiple processors. Furthermore, processing can be performed by one processor, or simultaneously, sequentially, or by two or more processors using other methods. Additionally, processor 1001 can be implemented using more than one chip.

[0421] The functions of the base station 10 and the user terminal 20 are implemented, for example, by reading specific software (programs) into hardware such as the processor 1001 and the memory 1002, so that the processor 1001 can perform calculations and control communication via the communication device 1004, or control at least one of reading out and writing data in the memory 1002 and the storage device 1003.

[0422] The processor 1001, for example, enables the operating system to operate and control the computer as a whole. The processor 1001 may also be configured as a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic devices, registers, etc. For example, at least a portion of the control unit 110 (210), the transmit / receive unit 120 (220), etc., described above may also be implemented by the processor 1001.

[0423] Furthermore, the processor 1001 reads programs (program code), software modules, data, etc., from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and performs various processes accordingly. As a program, a program that causes the computer to perform at least a portion of the operations described in the above embodiments can be used. For example, the control unit 110 (210) can also be implemented by a control program stored in the memory 1002 and operating in the processor 1001; similar implementations can be made for other functional blocks.

[0424] The memory 1002 may also be a computer-readable recording medium, such as being composed of at least one of read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), random access memory (RAM), or other suitable storage media. The memory 1002 may also be referred to as a register, cache, main memory (main storage device), etc. The memory 1002 is capable of storing executable programs (program code), software modules, etc., for implementing the wireless communication method according to one embodiment of the present disclosure.

[0425] Storage device 1003 may also be a computer-readable recording medium, such as at least one of a flexible disc, floppy disk, optical disk (e.g., compact disc ROM, CD-ROM), digital multifunction disk, Blu-ray disc, removable disk, hard disk, smart card, flash memory device (e.g., card, stick, key drive), magnetic stripe, database, server, or other suitable storage medium. Storage device 1003 may also be referred to as an auxiliary storage device.

[0426] The communication device 1004 is hardware (transmitting and receiving device) used for communication between computers via at least one of a wired network and a wireless network. It is also referred to as a network device, network controller, network interface card (NIC), communication module, etc. To implement at least one of, for example, Frequency Division Duplex (FDD) and Time Division Duplex (TDD), the communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. For example, the aforementioned transmit / receive unit 120 (220) and transmit / receive antenna 130 (230) may also be implemented by the communication device 1004. The transmit / receive unit 120 (220) may also be implemented by physically or logically separating the transmit unit 120a (220a) and the receive unit 120b (220b).

[0427] Input device 1005 is an input device that receives input from external sources (e.g., keyboard, mouse, microphone, switch, button, sensor, etc.). Output device 1006 is an output device that performs output to external sources (e.g., display, speaker, light-emitting diode (LED) lamp, etc.). Alternatively, input device 1005 and output device 1006 can also be an integrated structure (e.g., touch panel).

[0428] Furthermore, the processor 1001, memory 1002, and other devices are connected via a bus 1007 for communicating information. The bus 1007 can be configured as a single bus or as different buses between the devices.

[0429] Furthermore, the base station 10 and the user terminal 20 can also 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 this hardware can be used to implement some or all of the functional blocks. For example, the processor 1001 can also be implemented using at least one of these hardware components.

[0430] (Modified Example)

[0431] Furthermore, the terms described in this disclosure, as well as those necessary for understanding this disclosure, may be rewritten with terms having the same or similar meanings. For example, channel, symbol, and signal (signal or signaling) may be interchanged. Additionally, a signal may also be a message. A reference signal can also be abbreviated as RS, and may be referred to as pilot, pilot signal, etc., depending on the applied standard. Furthermore, a component carrier (CC) may also be referred to as cell, frequency carrier, carrier frequency, etc.

[0432] A radio frame can also be composed of one or more periods (frames) in the time domain. Each of these periods (frames) that constitutes a radio frame can also be called a subframe. Furthermore, a subframe can also be composed of one or more time slots in the time domain. A subframe can also be a fixed time length (e.g., 1 ms) independent of the parameter set (numerology).

[0433] Here, the parameter set can also refer to communication parameters applied in at least one of the transmission and reception of a signal or channel. For example, the parameter set can also represent at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame structure, specific filtering processing performed by the transmitter and receiver in the frequency domain, and specific windowing processing performed by the transmitter and receiver in the time domain.

[0434] In the time domain, a time slot can also be composed of one or more symbols (Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.). Furthermore, a time slot can also be a time unit based on a set of parameters.

[0435] A time slot can also contain multiple mini-time slots. Each mini-time slot can also consist of one or more symbols in the time domain. Furthermore, a mini-time slot can also be called a sub-time slot. A mini-time slot can also consist of fewer symbols than a time slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a mini-time slot can also be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using mini-time slots can also be called PDSCH (PUSCH) mapping type B.

[0436] Radio frames, subframes, time slots, mini-time slots, and symbols all represent time units for transmitting signals. Radio frames, subframes, time slots, mini-time slots, and symbols can also use their respective other names. Furthermore, the time units such as frames, subframes, time slots, mini-time slots, and symbols in this disclosure can be interchanged.

[0437] For example, a subframe can also be called a TTI, multiple consecutive subframes can also be called a TTI, and a time slot or a mini-time slot can also be called a TTI. That is to say, at least one of a subframe and a TTI can be a subframe in existing LTE (1ms), a period shorter than 1ms (e.g., 1-13 symbols), or a period longer than 1ms. In addition, the unit representing TTI may not be called a subframe, but a time slot, mini-time slot, etc.

[0438] Here, TTI refers, for example, to the smallest unit of time for scheduling in wireless communication. For instance, in an LTE system, the base station schedules radio resources (frequency bandwidth, transmit power, etc., available to each user terminal) in TTI units. However, the definition of TTI is not limited to this.

[0439] TTI can also be a unit of time for transmitting channel-coded data packets (transmission blocks), code blocks, codewords, etc., and can also be a unit of processing such as scheduling and link adaptation. In addition, when a TTI is given, the actual time interval (e.g., the number of symbols) mapped to the transmission block, code block, codeword, etc. can be shorter than the TTI.

[0440] Additionally, where a time slot or a mini-time slot is referred to as a TTI, more than one TTI (i.e., more than one time slot or more than one mini-time slot) can also serve as the minimum time unit for scheduling. Furthermore, the number of time slots (mini-time slots) constituting the minimum time unit of the schedule can also be controlled.

[0441] A TTI with a duration of 1 ms can also be referred to as a normal TTI (TTI in 3GPP Rel.8-12), standard TTI, long TTI, normal subframe, standard subframe, long subframe, time slot, etc. A TTI shorter than a normal TTI can also be referred to as a shortened TTI, short TTI, partial TTI (partial or fractional TTI), shortened subframe, short subframe, mini time slot, sub-time slot, time slot, etc.

[0442] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) can also be rewritten as a TTI with a duration of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) can also be rewritten as a TTI with a duration of less than a long TTI but more than 1 ms.

[0443] A resource block (RB) is a unit of resource allocation in both the time and frequency domains. In the frequency domain, it can also contain one or more consecutive subcarriers. The number of subcarriers in an RB can be the same regardless of the parameter set, for example, it can be 12. The number of subcarriers in an RB can also be determined based on the parameter set.

[0444] Furthermore, an RB can contain one or more symbols in the time domain, and can also be a time slot, a mini-time slot, a subframe, or the length of a TTI. A TTI, a subframe, etc., can also be composed of one or more resource blocks.

[0445] In addition, one or more RBs can also be referred to as Physical Resource Blocks (PRBs), Sub-Carrier Groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB pairs, etc.

[0446] Furthermore, a resource block can also consist of one or more resource elements (REs). For example, an RE can also be a radio resource area consisting of a subcarrier and a symbol.

[0447] The Bandwidth Part (BWP) (also referred to as partial bandwidth, etc.) can also represent a subset of consecutive common resource blocks (RBs) used for a certain parameter set in a carrier. Here, common RBs can also be determined by indexing RBs based on a common reference point of the carrier. PRBs can also be defined in a BWP and appended with numbers within that BWP.

[0448] A BWP can also include a UL BWP (BWP for UL) and a DL BWP (BWP for DL). For a UE, one or more BWPs can also be set within a single carrier.

[0449] At least one of the configured BWPs can be active, and the UE may not intend to transmit or receive specific signals / channels outside of the active BWPs. Furthermore, the terms "cell," "carrier," etc., in this disclosure can be rewritten as "BWP."

[0450] Furthermore, the structures described above, such as radio frames, subframes, time slots, mini-time slots, and symbols, are merely illustrative. For example, the number of subframes contained in a radio frame, the number of time slots in each subframe or radio frame, the number of mini-time slots contained within a time slot, the number of symbols and RBs contained in a time slot or mini-time slot, the number of subcarriers contained in an RB, and the number of symbols in a TTI, symbol length, and cyclic prefix (CP) length can be varied in many ways.

[0451] Furthermore, the information, parameters, etc., described in this disclosure can be represented by absolute values, relative values ​​with respect to a specific value, or other corresponding information. For example, wireless resources can also be indicated by a specific index.

[0452] In this disclosure, the names used for parameters, etc., are not limiting names in any respect. Furthermore, the mathematical expressions, etc., using these parameters may differ from those explicitly disclosed in this disclosure. Various channels (PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name; therefore, the various names assigned to these various channels and information elements are not limiting names in any respect.

[0453] The information, signals, etc., described in this disclosure can also be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc., which may be mentioned throughout the above description, can also be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination thereof.

[0454] Furthermore, information, signals, etc., can be output in at least one of the following directions: from higher level (upper layer) to lower level (lower layer), and from lower layer to higher level. Information, signals, etc., can also be input and output via multiple network nodes.

[0455] Input and output information and signals can be stored in a specific location (such as memory) or managed using management tables. Input and output information and signals can be overwritten, updated, or appended. Output information and signals can also be deleted. Input information and signals can also be sent to other devices.

[0456] The notification of information is not limited to the methods / implementations described in this disclosure, and may also be carried out by other methods. For example, the notification of information in this disclosure may also be implemented by physical layer signaling (e.g., downlink control information (DCI), uplink control information (UCI), etc.), higher layer signaling (e.g., radio resource control (RRC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB) etc.), medium access control (MAC) signaling), other signals, or combinations thereof.

[0457] In addition, physical layer signaling can also be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signals), L1 control information (L1 control signals), etc. Furthermore, RRC signaling can also be referred to as RRC messages, such as RRC connection setup messages, RRC connection reconfiguration messages, etc. Additionally, MAC signaling can also be notified using, for example, the MAC control element (CE).

[0458] Furthermore, notification of specific information (e.g., a notification that “is X”) is not limited to explicit notification, but can also be implicit (e.g., by not providing that specific information, or by providing other information).

[0459] The determination can be made by a value represented by a single bit (0 or 1), by a true or false value (boolean), or by a numerical comparison (e.g., a comparison with a specific value).

[0460] Whether it is called software, firmware, middleware, microcode, hardware description language, or any other name, software should be broadly interpreted as instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0461] Furthermore, software, instructions, and information can also be sent and received via a transmission medium. For example, when software is sent from a website, server, or other remote source using at least one of wired technologies (coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL) etc.) and wireless technologies (infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0462] The terms “system” and “network” as used in this disclosure are used interchangeably. “Network” may also refer to devices included in a network (e.g., a base station).

[0463] In this disclosure, the terms "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", "beamwidth", "beam angle", "antenna", "antenna element", and "panel" are used interchangeably.

[0464] In this disclosure, the terms "Base Station (BS)", "Wireless 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", and "Component Carrier" are used interchangeably. There are also instances where the terms macro cell, small cell, femtocell, and picocell are used to refer to a base station.

[0465] 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 divided into multiple smaller areas, each of which can also provide communication services through a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). Terms such as "cell" or "sector" refer to a portion or all of the coverage area of ​​at least one of the base station and base station subsystem providing communication services within that coverage area.

[0466] In this disclosure, the terms “Mobile Station (MS)”, “user terminal”, “user equipment (UE)”, and “terminal” are used interchangeably.

[0467] There are also instances where mobile stations are referred to as subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless terminals, remote terminals, handsets, user agents, mobile clients, clients, or several other appropriate terms.

[0468] At least one of the base station and the mobile station can also be referred to as a transmitting device, a receiving device, a wireless communication device, etc. Additionally, at least one of the base station and the mobile station can also be a device mounted on a mobile body, the mobile body itself, etc. This mobile body can be a means of transportation (e.g., a vehicle, an airplane, etc.), a mobile body moving in an unmanned manner (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanized or unmanned). Furthermore, at least one of the base station and the mobile station also includes devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station can also be an Internet of Things (IoT) device such as a sensor.

[0469] Furthermore, the base station in this disclosure can also be rewritten as a user terminal. For example, various methods / implementations of this disclosure can be applied to structures where communication between the base station and the user terminal is rewritten as communication between multiple user terminals (e.g., it can also be referred to as device-to-device (D2D) or vehicle-to-everything (V2X)). In this case, it can also be configured such that the user terminal 20 has the functions of the base station 10 described above. In addition, terms such as "uplink" and "downlink" can also be rewritten as terms corresponding to communication between terminals (e.g., "sidelink"). For example, uplink channel, downlink channel, etc., can also be rewritten as sidelink channel.

[0470] Similarly, the user terminal in this disclosure can also be rewritten as a base station. In this case, it can also be configured such that the base station 10 has the functions of the user terminal 20 described above.

[0471] In this disclosure, operations are assumed to be performed by the base station, and sometimes, depending on the circumstances, by its upper node. Clearly, in a network containing one or more network nodes having a base station, various operations for communication with a terminal can be performed by the base station, one or more network nodes other than the base station (e.g., considering a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc., but not limited to these), or combinations thereof.

[0472] The various methods / implementations described in this disclosure can be used individually, in combination, or switched as needed during execution. Furthermore, the processing procedures, sequences, flowcharts, etc., of the various methods / implementations described in this disclosure can be rearranged as long as they do not contradict each other. For example, with respect to the method described in this disclosure, the illustrated order is used to indicate various steps, but the order in which they are indicated is not limited.

[0473] The various methods / implementations described in this disclosure can also be applied to 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) (xG (x is, for example, an integer or a decimal)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New Radio Access (NX), Future generation radio access (FX), Global System for Mobile Communications (GSM), CDMA2000, Ultra Mobile Broadband (UMB), and IEEE This includes 802.11 (Wi-Fi, registered trademark), IEEE 802.16 (WiMAX, registered trademark), IEEE 802.20, Ultra-Wideband (UWB), Bluetooth (registered trademark), systems utilizing other suitable wireless communication methods, and next-generation systems derived from them. Furthermore, multiple systems can be combined (e.g., LTE or LTE-A, combinations with 5G, etc.) for application.

[0474] As used in this disclosure, the word "based on" does not mean "based on only" unless otherwise specified. In other words, the word "based on" means both "based on only" and "based on at least".

[0475] Any reference to an element using the designations "first," "second," etc., as used in this disclosure does not comprehensively limit the quantity or order of these elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Therefore, references to the first and second elements do not imply that only two elements may be used, or that the first element must take precedence over the second element in some form.

[0476] The term "determining" as used in this disclosure can encompass a wide variety of operations. For example, "determining" can also refer to judging, calculating, computing, processing, deriving, investigating, looking up (e.g., searching in a table, database, or other data structure), and ascertaining.

[0477] In addition, "judgment (decision)" can also refer to receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, accessing (e.g., accessing data in memory), etc., as situations where "judgment (decision)" is performed.

[0478] Furthermore, "judgment (decision)" can also refer to situations where resolving, selecting, choosing, establishing, or comparing are considered as making a "judgment (decision)". In other words, "judgment (decision)" can also refer to certain actions as situations where a "judgment (decision)" is made.

[0479] In addition, "judgment (decision)" can also be rewritten as "assuming", "expecting", "considering", etc.

[0480] The term "maximum transmit power" as used in this disclosure may refer to the maximum value of the transmit power, the nominal maximum transmit power (the nominal UE maximum transmit power), or the rated maximum transmit power (the rated UE maximum transmit power).

[0481] As used in this disclosure, the terms "connected," "coupled," or all variations thereof, mean any direct or indirect connection or combination between two or more elements, and can include cases where there is one or more intermediate elements between two mutually "connected" or "coupled" elements. The combination or connection between elements can be physical, logical, or a combination thereof. For example, "connected" can also be rewritten as "access."

[0482] In this disclosure, when connecting two elements, it is possible to consider using more than one wire, cable, printed electrical connection, etc., and as several non-limiting and non-inclusive examples, using electromagnetic energy with wavelengths in the wireless frequency domain, microwave region, light (both visible and invisible) region, to "connect" or "combine" them with each other.

[0483] In this disclosure, the term "A is different from B" can also mean "A and B are different from each other". Additionally, the term can also mean "A and B are each different from C". Terms such as "separate" and "combined" can also be interpreted in the same way as "different".

[0484] In this disclosure, the terms "include," "including," and variations thereof, as used, mean inclusiveness, similar to the term "comprising." Furthermore, the term "or" as used in this disclosure does not mean XOR.

[0485] In this disclosure, for example, in cases where articles are added through translation, such as a, an, and the in English, the disclosure may also include cases where the noun following these articles is in a plural form.

[0486] The invention disclosed herein has been described in detail above. However, it will be apparent to those skilled in the art that the invention is not limited to the embodiments described herein. The invention can be implemented with modifications and variations without departing from the spirit and scope of the invention as defined by the claims. Therefore, the description in this disclosure is for illustrative purposes only and is not intended to limit the invention in any way.

Claims

1. A terminal, comprising: The receiving unit receives a first setting of a control resource set (CORESET) having multiple transmit setting indication states (TCI states), and a second setting of multiple BFD-RS sets including one or more beam failure detection (BFD) reference signals (first BFD-RS) associated with the CORESET and associated with multiple transmit / receive points (TRPs). It also receives a media access control element (MAC CE) for indicating updates to one or more BFD-RSs within the multiple BFD-RS sets. The control unit determines one or more second BFD-RS based on the first setting, the second setting, and the MAC CE.

2. The terminal according to claim 1, wherein, The MAC CE has a new logical channel ID, namely the new LCID.

3. The terminal according to claim 1, wherein, In the event that one or more of the first BFD-RSs are not set, the control unit selects the CORESET to be used in the decision of the one or more first BFD-RSs based on at least one of the monitoring period of the search space set and the CORESET index.

4. A wireless communication method for a terminal, comprising: The system receives a first setting of a control resource set, namely CORESET, having multiple transmit setting indication states, i.e., multiple TCI states; and receives a second setting of multiple BFD-RS sets, including a first reference signal (i.e., a first BFD-RS) associated with the CORESET and associated with multiple transmit / receive points (TRPs); and receives a Media Access Control-Control Element (MAC CE) for indicating updates to one or more BFD-RSs in the multiple BFD-RS sets; and... Based on the first setting, the second setting, and the MAC CE, determine one or more steps of the second BFD-RS.

5. A base station, comprising: The transmitting unit transmits a first setting of a control resource set, namely CORESET, having multiple transmission setting indication states, i.e., multiple TCI states, and transmits a second setting of multiple BFD-RS sets, including a first reference signal (i.e., a first BFD-RS) associated with the CORESET and associated with multiple transmit / receive points (TRPs); and The control unit determines one or more second BFD-RS used by the BFD. The transmitting unit transmits a Media Access Control-Control Element (MAC CE) that indicates an update of one or more BFD-RSs in the plurality of BFD-RS sets and is associated with one or more second BFD-RSs.

6. A system having a terminal and a base station, The terminal has: The receiving unit receives a first setting of a control resource set (CORESET) having multiple transmit setting indication states (TCI states), and a second setting of multiple BFD-RS sets including one or more beam failure detection (BFD) reference signals (first BFD-RS) associated with the CORESET and associated with multiple transmit / receive points (TRPs). It also receives a media access control element (MAC CE) for indicating updates to one or more BFD-RSs within the multiple BFD-RS sets. The control unit, based on the first setting, the second setting, and the MAC CE, determines one or more second BFD-RS. The base station has: The transmitting unit transmits the first setting, the second setting, and the MAC CE; and The control unit determines one or more of the second BFD-RS.

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