Terminal, wireless communication method, base station and system

Abstract

A terminal according to one embodiment of the present disclosure includes: a reception unit that, when a first reference signal set for beam failure detection and a second reference signal set for a candidate beam are supported, or a third reference signal set for beam failure detection and a fourth reference signal set for a candidate beam are supported instead of the first reference signal set and the second reference signal set, receives one of either information relating to the second reference signal set or information relating to the fourth reference signal set; and a control unit that, when information relating to the first reference signal set and information relating to the third reference signal set are not provided, determines a reference signal set to be used in beam failure detection on the basis of one of either the information relating to the second reference signal set or the information relating to the fourth reference signal set.

Description

[Technical Field]

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

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

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

[0004] [Non-Patent Document 1] 3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010 Summary of the Invention [Problem to be solved by the invention]

[0005] In future wireless communication systems, it is being considered that terminals will perform beam failure detection (BFD) and beam failure recovery (BFR). In addition to cell-based BFD / BFR, it is also expected that other unit-based BFD / BFR (e.g., TRP-based / panel-based) BFD / BFR will be supported in Rel. 17 NR and later.

[0006] However, if BFD / BFR per TRP is supported in addition to BFD / BFR per cell, there is no sufficient consideration on how to control BFD / BFR (e.g., determining the reference signal (RS) to be used for BFD / BFR). If BFD / BFR control is not performed properly, there is a risk of communication quality degradation.

[0007] Therefore, the present disclosure provides a terminal and a wireless communication method that can appropriately perform BFD / BFR even when BFD / BFR other than on a cell-by-cell basis is supported. 、 base station and systems One of the aims is to provide [Means for solving the problem]

[0008] In a terminal according to an embodiment of the present disclosure, when a first reference signal set for beam failure detection and a second reference signal set for candidate beams, or a third reference signal set for beam failure detection and a fourth reference signal set for candidate beams are supported instead of the first reference signal set and the second reference signal set, a terminal may perform a process for determining whether or not a second reference signal set for beam failure detection is supported. Second information relating to the fourth reference signal set Fourth a receiver for receiving one of the information sets; 1st information and the third reference signal set ThirdIf no information is provided, emotion or the fourth emotion and a control unit that determines a reference signal set to be used for beam fault detection based on one of the pieces of information. [Effects of the Invention]

[0009] According to one aspect of the present disclosure, even when BFD / BFR other than on a cell-by-cell basis is supported, BFD / BFR can be performed appropriately. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of a beam recovery procedure. [Figure 2] 2A and 2B are diagrams illustrating an example of determining a BFD-RS set according to the first embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of a base station according to an embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. [Figure 7] FIG. 7 is a diagram illustrating an example of a vehicle according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] (TCI, spatial relations, QCL) In NR, it is being considered to control the reception processing (e.g., at least one of reception, demapping, demodulation, and decoding) and transmission processing (e.g., at least one of transmission, mapping, precoding, modulation, and encoding) in the UE of at least one of a signal and a channel (referred to as signal / channel) based on the transmission configuration indication state (TCI state).

[0012] The TCI state may represent that which is applied to a downlink signal / channel, and the equivalent of the TCI state which is applied to an uplink signal / channel may be expressed as a spatial relation.

[0013] The TCI state is information about the quasi-co-location (QCL) of signals / channels, and may also be called spatial reception parameters, spatial relation information, etc. The TCI state may be configured in the UE for each channel or signal.

[0014] A QCL is an index that indicates the statistical properties of a signal / channel. For example, if a signal / channel has a QCL relationship with another signal / channel, it may mean that it can be assumed that at least one of the Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (e.g., spatial Rx parameter) is the same between these different signals / channels (i.e., they are QCLs with respect to at least one of these).

[0015] The spatial reception parameters may correspond to a reception beam (e.g., a reception analog beam) of the UE, and the beam may be determined based on a spatial QCL. A QCL (or at least one element of a QCL) in the present disclosure may be replaced with an sQCL (spatial QCL).

[0016] A plurality of types (QCL types) of QCLs may be defined. For example, four QCL types A and B may be provided, each having different parameters (or parameter sets) that can be assumed to be the same. The parameters (which may also be referred to as QCL parameters) are listed below: QCL Type A (QCL-A): Doppler shift, Doppler spread, mean delay and delay spread, QCL Type B (QCL-B): Doppler shift and Doppler spread, QCL Type C (QCL-C): Doppler shift and mean delay, · QCL Type D (QCL-D): Spatial reception parameters.

[0017] The assumption by a UE that a Control Resource Set (CORESET), channel, or reference signal has a specific QCL (e.g., QCL type D) relationship with another CORESET, channel, or reference signal may be referred to as a QCL assumption.

[0018] The UE may determine at least one of a transmit beam (Tx beam) and a receive beam (Rx beam) for a signal / channel based on the TCI condition or QCL assumption of the signal / channel.

[0019] The TCI state may be, for example, information about the QCL between the target channel (in other words, the Reference Signal (RS) for the channel) and another signal (e.g., another RS). The TCI state may be set (indicated) by higher layer signaling, physical layer signaling, or a combination thereof.

[0020] The physical layer signaling may be, for example, Downlink Control Information (DCI).

[0021] The channel for which the TCI state or spatial relationship is set (specified) may be, for example, at least one of a downlink shared channel (Physical Downlink Shared Channel (PDSCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), an uplink shared channel (Physical Uplink Shared Channel (PUSCH)), and an uplink control channel (Physical Uplink Control Channel (PUCCH)).

[0022] Furthermore, the RS that has a QCL relationship with the channel may be, for example, at least one of a Synchronization Signal Block (SSB), a Channel State Information Reference Signal (CSI-RS), a Sounding Reference Signal (SRS), a CSI-RS for tracking (also called a Tracking Reference Signal (TRS)), and a QCL detection reference signal (also called a QRS).

[0023] An SSB is a signal block that includes at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). An SSB may also be referred to as an SS / PBCH block.

[0024] An RS of QCL type X in a TCI state may refer to an RS that has a relationship of QCL type X with (the DMRS of) a certain channel / signal, and this RS may be called a QCL source of QCL type X in the TCI state.

[0025] A QCL Type A RS is always configured for PDCCH and PDSCH, and a QCL Type D RS may be configured additionally. Because it is difficult to estimate Doppler shift, delay, etc. by one-shot reception of a DMRS, a QCL Type A RS is used to improve channel estimation accuracy. A QCL Type D RS is used to determine the receiving beam when receiving a DMRS.

[0026] For example, TRS1-1, 1-2, 1-3, and 1-4 are transmitted, and TRS1-1 is indicated as a QCL type C / D RS according to the TCI status of the PDSCH. By indicating the TCI status, the UE can use information obtained from past periodic reception / measurement results of TRS1-1 for reception / channel estimation of the DMRS for PDSCH. In this case, the QCL source of the PDSCH is TRS1-1, and the QCL target is the DMRS for PDSCH.

[0027] (Multi-TRP) In NR, one or more Transmission / Reception Points (TRPs) (multi-TRPs (MTRPs)) are considered to perform DL transmission to a UE using one or more panels (multi-panels). Also, it is considered that a UE performs UL transmission to one or more TRPs using one or more panels.

[0028] Note that multiple TRPs may correspond to the same cell identifier (ID), or different cell IDs. The cell ID may be a physical cell ID or a virtual cell ID.

[0029] Multi-TRPs (e.g., TRPs #1 and #2) may be connected by ideal / non-ideal backhauls to exchange information, data, etc. Each TRP of the multi-TRP may transmit a different code word (CW) and a different layer. Non-Coherent Joint Transmission (NCJT) may be used as a form of multi-TRP transmission.

[0030] In the NCJT, for example, TRP#1 performs modulation mapping and layer mapping on a first codeword to transmit a first PDSCH using a first number of layers (e.g., two layers) with a first precoding, and TRP#2 performs modulation mapping and layer mapping on a second codeword to transmit a second number of layers (e.g., two layers) with a second precoding.

[0031] Note that multiple PDSCHs (multi-PDSCHs) that are non-coherent may be defined as partially or completely overlapping in at least one of the time and frequency domains, i.e., a first PDSCH from a first TRP and a second PDSCH from a second TRP may overlap in at least one of the time and frequency resources.

[0032] The first PDSCH and the second PDSCH may be assumed to be not quasi-co-located (Quasi-Co-Location (QCL)). Reception of multiple PDSCHs may be interpreted as simultaneous reception of PDSCHs that are not of a certain QCL type (e.g., QCL type D).

[0033] Multiple PDSCHs from multiple TRPs (which may also be referred to as multiple PDSCHs) may be scheduled using one DCI (single DCI, single PDCCH) (single-master mode, single-DCI based multi-TRP). Multiple PDSCHs from multiple TRPs may also be scheduled using multiple DCIs (multiple DCI, multiple PDCCHs) (multi-master mode, multi-DCI based multi-TRP).

[0034] In URLLC for multiple TRPs, it is considered that PDSCH (transport block (TB) or codeword (CW)) repetition across multiple TRPs is supported. Repetition schemes (URLLC schemes, e.g., schemes 1, 2a, 2b, 3, and 4) across multiple TRPs in the frequency domain, layer (spatial) domain, or time domain are supported. 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, the redundancy version (RV) is the same for multiple TRPs. In scheme 2b, the RVs may be the same or different for multiple TRPs. In schemes 3 and 4, multiple PDSCHs from multiple TRPs are time division multiplexed (TDM). In scheme 3, multiple PDSCHs from multiple TRPs are transmitted in one slot. In scheme 4, multiple PDSCHs from multiple TRPs are transmitted in different slots.

[0035] Such a multi-TRP scenario allows for more flexible transmission control using good quality channels.

[0036] To support intra-cell (having the same cell ID) and inter-cell (having different cell IDs) multi-TRP transmission based on multiple PDCCHs, in the RRC configuration information for linking multiple pairs of PDCCHs and PDSCHs with multiple TRPs, one control resource set (CORESET) in the PDCCH configuration information (PDCCH-Config) may correspond to one TRP.

[0037] If at least one of the following conditions 1 and 2 is satisfied, the UE may determine that the transmission is a multi-TRP transmission based on the multi-DCI transmission. In this case, the TRP may be replaced with a CORESET pool index. [Condition 1] A CORESET pool index of 1 is set. [Condition 2] Two different values ​​of the CORESET pool index (for example, 0 and 1) are set.

[0038] If the following condition is met, the UE may determine that the state is multi-TRP based on a single DCI, in which case the two TRPs may be interpreted as two TCI states indicated by the MAC CE / DCI. [conditions] "Enhanced TCI States Activation / Deactivation for UE-specific PDSCH MAC CE" is used to indicate one or two TCI states for one codepoint of the TCI field in the DCI.

[0039] The DCI for common beam instruction may be a UE-specific DCI format (e.g., DL DCI format (e.g., 1_1, 1_2), UL DCI format (e.g., 0_1, 0_2)), or may be a UE-group common DCI format.

[0040] (Beam Failure Detection(BFD) / Beam Failure Recovery(BFR)) In NR, communication is performed using beamforming. For example, a UE and a base station (e.g., a gNB (gNodeB)) may use a beam used to transmit a signal (also called a transmit beam or Tx beam) and a beam used to receive a signal (also called a receive beam or Rx beam).

[0041] When beamforming is used, it is expected that radio link quality will deteriorate due to increased susceptibility to interference from obstacles. This deterioration in radio link quality may lead to frequent radio link failures (RLF). Since RLF requires cell reconnection, frequent RLF occurrences will result in a degradation of system throughput.

[0042] In NR, in order to suppress the occurrence of RLF, when the quality of a specific beam deteriorates, a procedure for switching to another beam (which may also be called Beam Recovery (BR), Beam Failure Recovery (BFR), or L1 / L2 (Layer 1 / Layer 2) beam recovery) is performed. The BFR procedure may also be simply called BFR.

[0043] Note that a beam failure (BF) in this disclosure may also be referred to as a link failure.

[0044] Figure 1 shows an example of a beam recovery procedure in Rel.15 NR. The number of beams is merely an example and is not limited to this. In the initial state (step S101), the UE performs measurements based on Reference Signal (RS) resources transmitted using two beams.

[0045] The RS may be at least one of a Synchronization Signal Block (SSB) and a Channel State Information RS (CSI-RS). The SSB may also be called an SS / PBCH (Physical Broadcast Channel) block.

[0046] The RS may be at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), a Mobility Reference Signal (MRS), a signal included in an SSB, an SSB, a CSI-RS, a Demodulation Reference Signal (DMRS), a beam-specific signal, etc., or a signal configured by extending or modifying any of these. The RS measured in step S101 may also be called an RS for beam failure detection (Beam Failure Detection RS (BFD-RS)), an RS for use in a beam recovery procedure (BFR-RS), etc.

[0047] In step S102, the UE cannot detect the BFD-RS (or the reception quality of the RS is degraded) due to radio wave jamming from the base station. Such jamming can be caused by, for example, obstacles, fading, interference, etc. between the UE and the base station.

[0048] The UE detects a beam failure when a predetermined condition is met. The UE may detect the occurrence of a beam failure, for example, when the Block Error Rate (BLER) is less than a threshold for all configured BFD-RS (BFD-RS resource configurations). When the occurrence of a beam failure is detected, the lower layer (physical (PHY) layer) of the UE may notify (indicate) a beam failure instance to the upper layer (MAC layer).

[0049] The criteria for the determination are not limited to BLER, but may be Layer 1 Reference Signal Received Power (L1-RSRP) in the physical layer. Also, instead of or in addition to RS measurement, beam failure detection may be performed based on a downlink control channel (PDCCH). The BFD-RS may be expected to be quasi-co-located (QCL) with the DMRS of the PDCCH monitored by the UE.

[0050] Here, QCL is an index that indicates the statistical properties of a channel. For example, if a signal / channel and another signal / channel have a QCL relationship, it may mean that it can be assumed that at least one of the Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (e.g., spatial Rx parameter) is the same between these different signals / channels (i.e., they are QCLs with respect to at least one of these).

[0051] The spatial reception parameters may correspond to a reception beam (e.g., a reception analog beam) of the UE, and the beam may be determined based on a spatial QCL. A QCL (or at least one element of a QCL) in the present disclosure may be replaced with an sQCL (spatial QCL).

[0052] Information about BFD-RS (e.g., RS index, resource, number, number of ports, precoding, etc.), information about beam fault detection (BFD) (e.g., the above-mentioned threshold), etc. may be configured (notified) to the UE using higher layer signaling, etc. Information about BFD-RS may also be referred to as information about BFR resources, etc.

[0053] When a higher layer (e.g., MAC layer) of the UE receives a beam failure instance notification from the PHY layer of the UE, it may start a predetermined timer (which may be called a beam failure detection timer). If the MAC layer of the UE receives a certain number of beam failure instance notifications (e.g., beamFailureInstanceMaxCount configured by RRC) before the timer expires, it may trigger a BFR (e.g., start one of the random access procedures described below).

[0054] If there is no notification from the UE, or if the base station receives a predetermined signal (beam recovery request in step S104) from the UE, the base station may determine that the UE has detected a beam failure.

[0055] In step S103, the UE starts searching for a new candidate beam to be used for new communication in order to recover the beam. The UE may select a new candidate beam corresponding to a predetermined RS by measuring the RS. The RS measured in step S103 may be called a new candidate RS, an RS for identifying a new candidate beam, an NCBI-RS (New Candidate Beam Identification RS), an RS for new beam identification, an RS for new beam identification, an NBI-RS (New Beam Identification RS), a CBI-RS (Candidate Beam Identification RS), a CB-RS (Candidate Beam RS), or the like. The NBI-RS may be the same as or different from the BFD-RS. Note that the new candidate beam may simply be called a candidate beam or candidate RS.

[0056] The UE may determine a beam corresponding to an RS that satisfies a predetermined condition as a new candidate beam. The UE may determine a new candidate beam, for example, based on an RS among the configured NBI-RSs whose L1-RSRP exceeds a threshold. Note that the criteria for determination are not limited to L1-RSRP. The L1-RSRP for SSB may be called SS-RSRP. The L1-RSRP for CSI-RS may be called CSI-RSRP.

[0057] Information about the NBI-RS (e.g., RS resources, number of ports, precoding, etc.), information about new beam identification (NBI) (e.g., the above-mentioned threshold), etc. may be configured (notified) to the UE using higher layer signaling, etc. Information about the new candidate RS (or NBI-RS) may be acquired based on information about the BFD-RS. Information about the NBI-RS may be referred to as information about resources for NBI, etc.

[0058] Note that BFD-RS, NBI-RS, etc. may be interchangeably read as Radio Link Monitoring RS (RLM-RS).

[0059] In step S104, the UE that has identified the new candidate beam transmits a beam failure recovery request (BFRQ). The beam recovery request may also be called a beam recovery request signal, a beam failure recovery request signal, or the like.

[0060] The BFRQ may be transmitted using, for example, at least one of an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), an uplink shared channel (Physical Uplink Shared Channel (PUSCH)), and a configured grant (CG) PUSCH.

[0061] The BFRQ may include information of the new candidate beam / new candidate RS identified in step S103. Resources for the BFRQ may be associated with the new candidate beam. The beam information may be notified using a beam index (BI), a port index of a predetermined reference signal, an RS index, a resource index (e.g., a CSI-RS resource indicator (CRI) or an SSB resource indicator (SSBRI)), etc.

[0062] In Rel. 15 NR, contention-based BFR (CB-BFR), which is a BFR based on a contention-based random access (RA) procedure, and contention-free BFR (CF-BFR), which is a BFR based on a contention-free random access procedure, are under consideration. In CB-BFR and CF-BFR, a UE may transmit a preamble (also referred to as an RA preamble, a random access channel (Physical Random Access Channel (PRACH)), a RACH preamble, etc.) as a BFRQ using a PRACH resource.

[0063] In CB-BFR, a UE may transmit a preamble randomly selected from one or more preambles. In CF-BFR, a UE may transmit a preamble assigned specifically to the UE by the base station. In CB-BFR, a base station may assign the same preamble to multiple UEs. In CF-BFR, a base station may assign a preamble individually to each UE.

[0064] Note that CB-BFR and CF-BFR may be referred to as CB PRACH-based BFR (CBRA-BFR) and CF PRACH-based BFR (CFRA-BFR), respectively. CBRA-BFR may be referred to as CBRA for BFR. CFRA-BFR may be referred to as CFRA for BFR.

[0065] Regardless of whether CB-BFR or CF-BFR is used, information about the PRACH resource (RA preamble) may be notified by, for example, higher layer signaling (such as RRC signaling). For example, the information may include information indicating a correspondence relationship between the detected DL-RS (beam) and the PRACH resource, and a different PRACH resource may be associated with each DL-RS.

[0066] In step S105, the base station that has detected the BFRQ transmits a response signal (which may be referred to as a gNB response, etc.) to the BFRQ from the UE. The response signal may include reconfiguration information (e.g., DL-RS resource configuration information) for one or more beams.

[0067] The response signal may be transmitted, for example, in the UE common search space of the PDCCH. The response signal may be signaled using a PDCCH (DCI) scrambled with a cyclic redundancy check (CRC) by a UE identifier (e.g., a Cell-Radio RNTI (C-RNTI)). The UE may determine at least one of a transmit beam and a receive beam to use based on the beam reconfiguration information.

[0068] The UE may monitor the response signal based on at least one of a control resource set (CORESET) for BFR and a search space set for BFR.

[0069] For CB-BFR, contention resolution may be determined to be successful if the UE receives a PDCCH corresponding to the C-RNTI associated with the UE.

[0070] Regarding the process of step S105, a period for the UE to monitor a response to the BFRQ from a base station (e.g., a gNB) may be set. This period may be referred to as, for example, a gNB response window, a gNB window, a beam recovery request response window, etc. If no gNB response is detected within this window period, the UE may retransmit the BFRQ.

[0071] In step S106, the UE may transmit a message indicating that the beam reconfiguration is complete to the base station. The message may be transmitted, for example, via the PUCCH or the PUSCH.

[0072] A beam recovery success (BR success) may indicate, for example, that step S106 has been reached, whereas a beam recovery failure (BR failure) may indicate, for example, that a predetermined number of BFRQ transmissions have been made or that a beam-failure-recovery-timer has expired.

[0073] Rel.15 supports the use of a random access procedure to perform beam recovery procedures (e.g., BFRQ notification) for beam failures detected in an SpCell (PCell / PSCell). On the other hand, Rel.16 supports the use of at least one of PUCCH (e.g., Scheduling Request (SR)) transmission for BFR and MAC CE (e.g., UL-SCH) transmission for BFR to perform beam recovery procedures (e.g., BFRQ notification) for beam failures detected in an SCell.

[0074] For example, the UE may transmit information about beam failure using MAC CE-based two-step. The information about beam failure may include information about the cell that detected the beam failure and information about new candidate beams (or new candidate RS indices).

[0075] [Step 1] If a BF is detected, a PUCCH-BFR (scheduling request (SR)) may be transmitted from the UE to the PCell / PSCell. Then, an UL grant (DCI) for step 2 below may be transmitted from the PCell / PSCell to the UE. If a beam failure is detected and there is a MAC CE (or UL-SCH) for transmitting information about a new candidate beam, step 1 (e.g., PUCCH transmission) may be omitted and step 2 (e.g., MAC CE transmission) may be performed.

[0076] [Step 2] Then, the UE may transmit information about the cell where beam failure was detected (failed) (e.g., cell index) and information about the new candidate beam to the base station (PCell / PSCell) via an uplink channel (e.g., PUSCH) using MAC CE. After that, through the BFR procedure, the QCL of the PDCCH / PUCCH / PDSCH / PUSCH may be updated to the new beam after a predetermined period (e.g., 28 symbols) after receiving a response signal from the base station.

[0077] Note that the numbers of these steps are for explanatory purposes only, and multiple steps may be combined or the order may be reversed. Furthermore, whether to perform BFR may be configured in the UE using higher layer signaling.

[0078] (BFD-RS) In Rel. 16, for each BWP of one serving cell, the UE may be provided with a set of periodic (P)-CSI-RS resource configuration indices q0 via higher layer parameters related to failure detection resources (e.g., failureDetectionResources, failureDetectionResourcesToAddModList, RadioLinkMonitoringConfig). The UE may also be provided with at least one set of P-CSI-RS resource configuration indices and SS / PBCH block indices q1 via a candidate beam RS list (candidateBeamRSList), an extended candidate beam RS list (candidateBeamRSListExt-r16), or a candidate beam RS list for SCells (candidateBeamRSSCellList-r16).

[0079] Here, q0 bar is written as "q0" with an overline. Hereinafter, q0 bar will be written simply as q0. q1 bar is written as "q1" with an overline. Hereinafter, q1 bar will be written simply as q1.

[0080] The set of P-CSI-RS resources q0 provided by the failure detection resources (e.g., predetermined higher layer parameters) may be referred to as explicit BFD-RS.

[0081] The UE may perform L1-RSRP measurements, etc., using RS resources corresponding to indices included in at least one of set q0 and set q1 to detect beam failure.

[0082] In the present disclosure, providing the above-mentioned higher layer parameters indicating information on indexes corresponding to BFD resources may be interchangeably read as configuring BFD resources, configuring a BFD-RS, etc. In the present disclosure, BFD resources, periodic CSI-RS resource configuration index or SSB index set q0, BFD-RS, BFD-RS set, and RS set may be interchangeably read.

[0083] If a UE is not provided with a BFD-RS set q0 by failure detection resources (e.g., failureDetectionResourcesToAddModList) for one of its serving cell's BWPs, the UE may be supported to determine the RS (set q0) to use for the BFD procedure according to the following implicit BFD-RS determination procedure:

[0084] [Implicit BFD-RS Decision Procedure] The UE determines the P-CSI-RS resource configuration indexes to include in set q0 that have the same value as the RS index in the RS set indicated by the TCI-State (TCI-State) for each CORESET that the UE uses to monitor the PDCCH. This set q0 may be referred to as implicit BFD-RS.

[0085] If there are two RS indices in one TCI state, set q0 contains RS indices that have a QCL type D configuration for the corresponding TCI state. The UE assumes that set q0 contains up to two RS indices. The UE assumes single-port RSs in set q0.

[0086] In this way, the UE may determine the BFD-RS (RS set) for beam failure detection based on the TCI state corresponding to the PDCCH / CORESET if the RS (e.g., BFD-RS) set is not explicitly provided (e.g., by a higher layer parameter).

[0087] (BFR in TRP) Prior to Rel. 16, cell-level BFR was supported, but from Rel. 17 onwards, it is expected that BFR will be supported on levels other than cell-level (for example, on a per-TRP basis). For example, in Rel. 17 and later, the introduction of an independent BFD-RS for each TRP is being considered for beam fault detection with multiple TRPs. Each TRP may be associated with one or more BFD-RSs.

[0088] In this disclosure, one or more BFD-RSs may be referred to as a set of BFD-RSs (BFD-RS set). In Rel. 15, up to two BFD-RSs are configured per BWP. For example, the two BFD-RSs may be referred to as one BFD-RS set. In Rel. 17 and later, the number of BFD-RSs per BWP does not need to be two; for example, the number of BFD-RSs may be determined based on UE capabilities.

[0089] Also, in Rel. 17 and later, in BFR with multiple TRPs, multiple (e.g., two) BFD-RS sets are supported per BWP, and up to N BFD-RS sets (N is any integer) may be supported per BFD-RS set.

[0090] Furthermore, in Rel. 17 and later, when one or more NBI-RSs (NBI-RS sets) are configured for each TRP in new beam identification for multiple TRPs, the introduction of an independent NBI-RS set configuration for each TRP is being considered. In this disclosure, one or more NBI-RSs may be referred to as a set of NBI-RSs (NBI-RS set).

[0091] In addition, from Rel. 17 onwards, it is being considered to associate one BFD-RS set with one NBI-RS set on a one-to-one basis.

[0092] For example, for BFR of multiple TRPs based on single / multiple DCIs, it may be supported to configure up to two BFD-RS sets and two BFD-RS sets per TRP.

[0093] In addition, if TRP-based (or panel-based) BFR is supported in addition to the cell-based BFR of Rel. 16 and earlier, BFR in a certain cell is assumed to be performed using either unit. In this case, whether to apply cell-based BFR or TRP-based BFR may be implicitly instructed to the UE.

[0094] For example, in each BWP of the serving cell, if an RS set for first beam failure detection (BFD-RS set) / RS set for candidate beam (NBI-RS set) is provided to the UE, BFR per cell is applied. On the other hand, in each BWP of the serving cell, if an RS set for second beam failure detection (BFD-RS set) / RS set for candidate beam (NBI-RS set) is provided to the UE instead of the RS set for first beam failure detection (BFD-RS set q0) / RS set for candidate beam (NBI-RS set q1), BFR per TRP may be applied.

[0095] For example, the RS set for the second beam failure detection (BFD-RS set) is composed of two BFD-RS sets (e.g., two sets q of (P)-CSI-RS resource configuration indexes). 0,0 bar (hereinafter, q 0,0 (also written as q) 0,1 bar (hereinafter, q 0,1 Also, the RS set for the second candidate beam (NBI-RS set) may include two NBI-RS sets (e.g., at least two sets q of P-CSI-RS resource configuration indexes and SS / PBCH block indexes). 1,0 bar (hereinafter, q 1,0 (also written as q) 1,1 bar (hereinafter, q 1,1 It may also include

[0096] BFD-RS Set q 0,0 is the NBI-RS set q 1,0 and the BFD-RS set q0,1 is the NBI-RS set q 1,1 Also, the NBI-RS set q 1,0 and, q 1,1 and may be set by separate upper layer parameters (for example, candidateBeamRSList1 and candidateBeamRSList2).

[0097] In this way, when a first BFD-RS set q0 / NBI-RS set q1 is provided in a certain cell (or a BWP of a certain cell), the UE performs BFR (e.g., cell-based BFR) using the RS set. On the other hand, when a second BFD-RS set q0 / NBI-RS set q1 is provided instead of the first BFD-RS set q0 / NBI-RS set q1, 0,0 , q 0,1 / NBI-RS Setq 1,0 , q 1,1 When provided, the RS set is used to perform BFR (for example, BFR in TRP units).

[0098] As mentioned above, in Rel. 16 and earlier, if the BFD-RS set q0 is not provided by higher layer parameters, the UE determines the BFD-RS set q0 based on the first rule (e.g., the TCI state for the CORESET used for PDCCH monitoring). In this case, the BFD-RS set used for BFR per TRP (e.g., set q0) is used. 0,0 , set q 0,1 ) is not provided, the UE may still be supported to determine the BFD-RS set based on the second rule.

[0099] However, in addition to cell-based BFR (e.g., BFD-RS set q0), TRP-based BFR (e.g., BFD-RS set q 0,0 / q 0,1 ) is supported, there is insufficient consideration as to how to control BFR when cell-based BFD-RS sets / TRP-based BFD-RS sets are not configured.

[0100] For example, the BFD-RS set q0 used for cell-based BFR and the BFD-RS set q1 used for TRP-based BFR are 0,0 , q 0,1 If and are not configured, the UE faces a problem of how to determine the BFR-RS set (for example, whether to apply the first rule or the second rule).

[0101] If the BFD-RS set to be used for BFR cannot be determined appropriately, communication quality may be degraded.

[0102] Therefore, the inventors have studied the control of BFR when TRP-based BFR is supported in addition to cell-based BFR (for example, determining BFD-RS when BFD-RS is not provided), and have conceived this embodiment.

[0103] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Wireless communication methods according to the embodiments may be applied independently or in combination.

[0104] In the present disclosure, "A / B" may mean "at least one of A and B" or may be read as A and B, or A or B. In the present disclosure, "A / B / C" may mean "at least one of A, B, and C" or may be read as A, B and C, or A, B, or C.

[0105] In the present disclosure, cell, serving cell, CC, carrier, BWP, DL BWP, UL BWP, active DL BWP, active UL BWP, and band may be interchangeable. In the present disclosure, index, ID, indicator, and resource ID may be interchangeable. In the present disclosure, support, control, controllable, operate, and operable may be interchangeable.

[0106] In the present disclosure, the terms configure, activate, update, indicate, enable, specify, and select may be read interchangeably.

[0107] In the present disclosure, the higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, etc., or a combination thereof. In the present disclosure, RRC, RRC signaling, RRC parameters, higher layer, higher layer parameters, RRC information elements (IEs), and RRC messages may be interchangeable.

[0108] The MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. The broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0109] In the present disclosure, MAC CE and activation / deactivation command may be read interchangeably.

[0110] In this disclosure, the terms panel, beam, spatial-domain filter, spatial setting, TCI state, UL TCI state, unified TCI state, unified beam, common TCI state, common beam, TCI assumption, QCL assumption, QCL parameter, spatial-domain receive filter, UE spatial-domain receive filter, UE receive beam, DL beam, DL receive beam, DL precoding, DL precoder, DL-RS, RS for QCL type D in TCI state / QCL assumption, RS for QCL type A in TCI state / QCL assumption, 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 may be interchangeable. In this disclosure, the terms QCL type X-RS, DL-RS associated with QCL type X, DL-RS with QCL type X, source of DL-RS, SSB, CSI-RS, and SRS may be interchangeable.

[0111] In the present disclosure, the terms panel, Uplink (UL) transmitting entity, TRP, spatial relationship, control resource set (CORESET), PDSCH, codeword, base station, antenna port of a certain signal (e.g., Demodulation Reference Signal (DMRS) port), antenna port group of a certain 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, transmission layer, spatial layer) may be interchangeable. Also, panel identifier (ID) and panel may be interchangeable. In the present disclosure, the terms TRP ID, TRP related ID, CORESET pool index, the position of one of two TCI states corresponding to one code point in a field in a DCI (ordinal number, first TCI state or second TCI state), and TRP may be read interchangeably.

[0112] In the present disclosure, panel, UE panel, RS port group, DMRS port group, SRS port group, RS resource group, DMRS resource group, SRS resource group, beam group, TCI state group, spatial relationship group, SRS resource indicator (SRI) group, antenna port group, antenna group, and CORESET group may be read as interchangeable.

[0113] The panel may be associated with at least one of a panel ID, a UL TCI state, a UL beam, an L beam, a DL RS resource, and spatial relationship information.

[0114] In the present disclosure, the terms "multi-TRP," "multi-TRP system," "multi-TRP transmission," "multi-PDSCH," "channel using multi-TRP," "channel using multiple TCI states / spatial relationships," "multi-TRP being enabled by RRC / DCI," "multiple TCI states / spatial relationships being enabled by RRC / DCI," and "at least one of multi-TRP based on a single DCI" and "multi-TRP based on multiple DCI" may be interchangeable. In the present disclosure, the terms "multi-TRP based on multiple DCI," and "setting a CORESET pool index (CORESETPoolIndex) value of 1 for the CORESET" may be interchangeable. In the present disclosure, the terms "multi-TRP based on a single DCI," and "at least one code point in the TCI field is mapped to two TCI states" may be interchangeable.

[0115] In the present disclosure, the following may be read interchangeably: single TRP, single DCI, single PDCCH, multi-TRP based on single DCI, single TRP system, single TRP transmission, single PDSCH, channel using single TRP, channel using one TCI state / spatial relationship, multi-TRP not being enabled by RRC / DCI, multiple TCI states / spatial relationships not being enabled by RRC / DCI, a CORESET pool index (CORESETPoolIndex) value of 1 not being set for any CORESET and no code point in the TCI field being mapped to two TCI states, and two TCI states on at least one TCI code point being activated.

[0116] In the present disclosure, TRP#1 (first TRP) may correspond to CORESET pool index=0 or may correspond to the first of two TCI states corresponding to one code point in the TCI field. TRP#2 (second TRP) may correspond to CORESET pool index=1 or may correspond to the second of two TCI states corresponding to one code point in the TCI field.

[0117] In the present disclosure, CORESET0, a CORESET having index 0, and a common CORESET may be read interchangeably.

[0118] In addition, in the present disclosure, signaling configuration, signaling, setting, configuration, setting information, instruction, instruction information, etc. may be read interchangeably.

[0119] In the present disclosure, BFR, BFR configuration, BFR procedure, BFD, BFD procedure, BFD-RS, BFD-RS configuration, RLM, RLM configuration, RLM procedure, RLM-RS, RLM-RS configuration, NBI, NBI configuration, NBI-RS, NBI-RS configuration may be interchangeable. In the present disclosure, per cell BFR, cell-specific BFR, and Rel. 15 / 16 BFR may be interchangeable. In the present disclosure, per TRP BFR, TRP-specific BFR, and Rel. 17 / Rel. 17 and later BFR may be interchangeable.

[0120] In the following embodiments of the present disclosure, we will describe cases where the number of BFD-RS sets and NBI-RS sets is a maximum of 2, but these numbers may be greater than 2, and ``two'' may be read as ``multiple.''

[0121] (Wireless communication method) The UE may be configured with a set of reference signals for beam failure detection (e.g., BFD-RS) / a set of reference signals for candidate beams (e.g., NBI-RS) for each BWP of the serving cell.

[0122] <Configuration of BFD-RS / NBI-RS in Cell-Level BFR> For each BWP of the serving cell, the UE may be provided with a set q0 of BFD-RS (e.g., periodic CSI-RS resource configuration index) by a higher layer parameter (e.g., failureDetectionResourcesToAddModList). Also, for each BWP of the serving cell, the UE may be provided with a set q1 of NBI-RS (e.g., at least one of a periodic CSI-RS resource configuration index and an SS / PBCH block index) by a higher layer parameter (e.g., candidateBeamRSList, candidateBeamRSListExt, or candidateBeamRSSCellList) for radio link quality measurement.

[0123] <Configuration of BFD-RS / NBI-RS in TRP-Level BFR> For each BWP of the serving cell, instead of set q0 and set q1, the UE may be provided with two sets q 0,0 and set q 0,1 of BFD-RS (e.g., periodic CSI-RS resource configuration index). Also, for each BWP of the serving cell, the UE may be provided with two sets q 0,0 and set q 0,1 of two NBI-RS (e.g., at least one of a periodic CSI-RS resource configuration index and an SS / PBCH block index) corresponding to set q 1,0 and set q 1,1 by a higher layer parameter (e.g., candidateBeamRSList1 and candidateBeamRSList2) for radio link quality measurement. The BFD-RS set q 0,0 may be associated with the NBI-RS set q 1,0 and the BFD-RS set q 0,1 may be associated with the NBI-RS set q 1,1 as well.

[0124] Two sets q of BFD-RS (e.g., periodic CSI-RS resource configuration index) 0,0 and set q 0,1 may be set (e.g., separately) by upper layer parameters related to beam failure detection resources, or may be set (e.g., separately) by other upper layer parameters.

[0125] Note that the two sets q of BFD-RS 0,0 and set q 0,1 may be configured to be provided when set q0 of BFD-RS is not provided. Alternatively, when the two sets q of BFD-RS 0,0 and set q 0,1 are provided, it may be configured that set q0 of BFD-RS is not provided.

[0126] <When the BFD-RS set is not provided> When the cell-specific BFD-RS set q0 is not provided, the UE determines the BFD-RS set q0 based on the first rule. The first rule may be to utilize the TCI state for the CORESET used for PDCCH monitoring.

[0127] More specifically, the first rule may be to determine set q0 such that it includes a P-CSI-RS resource configuration index having the same value as the RS index within the RS set indicated by the TCI state (TCI-State) for each CORESET used by the UE for PDCCH monitoring.

[0128] When the TRP-specific BFD-RS set q 0,0 or set q 0,1 is not provided, the UE determines the BFD-RS set q 0,0 / set q 0,1 based on the second rule. The second rule may be to utilize the TCI state for the first CORESET / second CORESET used for PDCCH monitoring.

[0129] More specifically, the second rule is to define a set q to include P-CSI-RS resource configuration indices that have the same values ​​as RS indices in the RS sets indicated by the TCI states (TCI-States) for the first and second CORESETs that the UE uses to monitor the PDCCH. 0,0 / setq 0,1 The UE may be provided with two CORESET pool indexes, 0 and 1, for the first and second CORESETs, or may be provided with no CORESET pool index for the first CORESET and a CORESET pool index of 1 for the second CORESET. For example, the first CORESET may correspond to the first CORESET pool index, and the second CORESET may correspond to the second CORESET pool index.

[0130] First Embodiment BFD-RS set q0 per cell / BFD-RS set q per TRP 0,0 or set q 0,1 If no NBI-RS set is provided, determine the BFD-RS set (e.g., determine whether to apply the first or second rule) based on the NBI-RS set provided (e.g., the contents of the provided NBI-RS set).

[0131] The UE uses the cell-based BFD-RS set q0 / TRP-based BFD-RS set q 0,0 or set q 0,1 If the BFD-RS set is not provided, the BFD-RS set may be determined (e.g., whether to apply the first rule or the second rule) based on the content of the provided NBI-RS set. In the present disclosure, the content of the provided NBI-RS set may be interpreted as upper layer parameters related to the NBI-RS or the content of upper layer parameters related to the NBI-RS.

[0132] When a first reference signal set (e.g., cell-based BFD-RS set q0) is not provided and a second reference signal set (e.g., NBI-RS set q1) is provided, the UE may determine a BFD-RS set (e.g., BFD-RS set q0) to apply to BFR based on a first rule (see FIG. 2A).

[0133] The UE also receives a third reference signal set (e.g., BFD-RS set q per TRP). 0,0 or set q 0,1 ) is not provided, and a fourth reference signal set (NBI-RS set q 1,0 / setq 1,1 (For example, set q 1,0 and set q 1,1 )) is provided, the UE selects a BFD-RS set to apply to BFR (e.g., BFD-RS set q) based on the second rule. 0,0 or set q 0,1 ) may be determined (see FIG. 2B).

[0134] That is, the UE must have a BFD-RS set (e.g., a cell-based BFD-RS set q0 and a TRP-based BFD-RS set q1). 0,0 / setq 0,1 ), if the provided NBI-RS set is the first NBI-RS set (e.g., set q1), the BFD-RS set q0 is determined based on the first rule. On the other hand, if the provided NBI-RS set is the second NBI-RS set (e.g., set q2), the BFD-RS set q0 is determined based on the first rule. 1,0 / setq 1,1 ), then based on the second rule, the BFD-RS set q 0,0 / setq 0,1 Determine.

[0135] In this way, if a BFD-RS set is not provided, the BFD-RS set can be determined based on the contents of the provided NBI-RS set, making it possible to appropriately determine the BFD-RS set even when BFR per TRP is supported.

[0136] Note that if cell-based BFR and TRP-based BFR are supported, a first NBI-RS set (e.g., set q1) and a second NBI-RS set (e.g., set q 1,0 / setq 1,1 ) may be always configured. That is, in a cell (or BWP) where cell-based BFR and TRP-based BFR are supported, the UE may always configure either a first NBI-RS set (e.g., set q1) or a second NBI-RS set (e.g., set q2). 1,0 / setq 1,1 ) is always configured. In a cell (or BWP) where cell-based BFR and TRP-based BFR are supported, the base station may configure a first NBI-RS set (e.g., set q1) and a second NBI-RS set (e.g., set q2). 1,0 / setq 1,1 ) or may be controlled to be always set.

[0137] <Variations> The UE uses the cell-based BFD-RS set q0 / TRP-based BFD-RS set q 0,0 / setq 0,1 If the BFD-RS set is not provided, the BFD-RS set may be determined (e.g., whether to apply the first rule or the second rule) based on predetermined upper layer parameters (e.g., other upper layer parameters other than the upper layer parameters related to the NBI-RS).

[0138] Assume that a first BFR (e.g., a cell-based BFR) is configured for a certain cell (or a BWP of a certain cell) by a higher layer parameter. If a BFD-RS set q0 is not provided, the UE may determine a BFD-RS (e.g., BFD-RS set q0) to apply to the BFR based on the first rule.

[0139] On the other hand, it is assumed that a second BFR (for example, a BFR per TRP) is configured for a certain cell (or a BWP of a certain cell) by a higher layer parameter.0,0 / setq 0,1 If no BFD-RS is provided, the BFD-RS to be applied to BFR based on the second rule (e.g., BFD-RS set q 0,0 / setq 0,1 ) may be determined.

[0140] In this case, for a certain cell (or a BWP of a certain cell), a first NBI-RS set (e.g., set q1) and a second NBI-RS set (e.g., set q 1,0 / setq 1,1 ) and both settings may be supported / allowed.

[0141] Alternatively, the UE may determine whether to apply the first rule or the second rule based on other conditions / rules / parameters. The other conditions / rules / parameters may be, for example, the configuration of PUCCH-SR / SR for BFR. For example, when multiple (e.g., two) PUCCH-SR / SR for BFR are configured, the UE may apply the second rule assuming that M-TRP BFR is applied.

[0142] The above two conditions may be switched by configuring higher layer parameters. For example, if a cell-specific BFR is configured in a UE and the BFD-RS set q0 is not configured for the BWP of the serving cell, the implicit BFD-RS for the cell-specific BFR in Rel. 15 / 16 is applied (e.g., the first rule is applied).

[0143] Otherwise, the UE is configured with a TRP-specific BFR and the BFD-RS set q for the BWP of the serving cell. 0,0 / setq 0,1 If not set, it may mean that the implicit BFD-RS for TRP-specific BFR in Rel. 17 and later applies (e.g., the second rule applies).

[0144] (wireless communication system) The configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above embodiments of the present disclosure or a combination thereof.

[0145] 3 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 may be a system that realizes communication using Long Term Evolution (LTE) or 5th generation mobile communication system New Radio (5G NR) specified by the Third Generation Partnership Project (3GPP).

[0146] The wireless communication system 1 may also support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC may include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

[0147] 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.

[0148] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity in which both the MN and the SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0149] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with a relatively wide coverage, and base stations 12 (12a-12c) that are located within the macrocell C1 and form small cells C2 that are smaller than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The locations and numbers of the cells and user terminals 20 are not limited to the embodiment shown in the figure. Hereinafter, when there is no need to distinguish between the base stations 11 and 12, they will be collectively referred to as base station 10.

[0150] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CC) and dual connectivity (DC).

[0151] Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band above 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may be a frequency band higher than FR2.

[0152] Furthermore, the user terminal 20 may perform communication using at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD) in each CC.

[0153] The multiple base stations 10 may be connected by wire (for example, optical fiber conforming to the Common Public Radio Interface (CPRI), an X2 interface, or the like) or wirelessly (for example, NR communication). For example, when NR communication is used as a backhaul between the base stations 11 and 12, the base station 11 corresponding to the upper station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0154] The base station 10 may be connected to the core network 30 directly or via another base station 10. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), and the like.

[0155] The user terminal 20 may be a terminal compatible with at least one of communication methods such as LTE, LTE-A, and 5G.

[0156] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the radio communication system 1. For example, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), or the like may be used in at least one of the downlink (DL) and uplink (UL).

[0157] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (for example, other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0158] In the wireless communication system 1, a downlink shared channel (Physical Downlink Shared Channel (PDSCH)) shared by each user terminal 20, a broadcast channel (Physical Broadcast Channel (PBCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), etc. may be used as the downlink channel.

[0159] Furthermore, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), etc. may be used as an uplink channel.

[0160] The PDSCH transmits user data, higher layer control information, System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit Master Information Block (MIB).

[0161] Lower layer control information may be transmitted by the PDCCH. The lower layer control information may include, for example, Downlink Control Information (DCI) including scheduling information for at least one of the PDSCH and the PUSCH.

[0162] Note that the DCI for scheduling the PDSCH may be referred to as a DL assignment, a DL DCI, etc., and the DCI for scheduling the PUSCH may be referred to as an UL grant, a UL DCI, etc. Note that the PDSCH may be interpreted as DL data, and the PUSCH may be interpreted as UL data.

[0163] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources to search for DCI. The search space corresponds to a search region and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor a CORESET associated with a certain search space based on the search space configuration.

[0164] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be called a search space set. Note that the terms "search space," "search space set," "search space setting," "search space set setting," "CORESET," "CORESET setting," etc. in the present disclosure may be read interchangeably.

[0165] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), acknowledgement information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0166] In the present disclosure, downlink, uplink, etc. may be expressed without adding "link." Also, various channels may be expressed without adding "Physical" to the beginning.

[0167] In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted as DL-RS.

[0168] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including the SS (PSS, SSS) and the PBCH (and DMRS for the PBCH) may be referred to as an SS / PBCH block, an SS Block (SSB), or the like. Note that the SS, SSB, and the like may also be referred to as reference signals.

[0169] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), etc. may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may also be called a user equipment-specific reference signal (UE-specific reference signal).

[0170] (base station) 4 is a diagram showing an example of the configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that the base station may include one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140.

[0171] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0172] The control unit 110 performs overall control of the base station 10. The control unit 110 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0173] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurement, etc. The control unit 110 may generate data to be transmitted as signals, control information, sequences, etc., and transfer them to the transceiver unit 120. The control unit 110 may perform call processing (setting up, releasing, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0174] The transceiver unit 120 may include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transceiver unit 120 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0175] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 1211 and an RF unit 122. The receiving unit may be composed of a reception processing unit 1212, an RF unit 122, and a measurement unit 123.

[0176] The transmitting and receiving antenna 130 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0177] The transceiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 120 may receive the above-mentioned uplink channel, uplink reference signal, etc.

[0178] The transceiver 120 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0179] The transceiver 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0180] The transceiver 120 (transmission processor 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0181] The transmitting / receiving unit 120 (RF unit 122) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna .

[0182] On the other hand, the transmitting / receiving unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna .

[0183] The transceiver 120 (reception processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, thereby acquiring user data, etc.

[0184] The transceiver 120 (measurement unit 123) may perform measurements on the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, etc. based on the received signal. The measurement unit 123 may measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 110.

[0185] The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30, other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0186] The transmitting section and receiving section of the base station 10 in the present disclosure may be configured by at least one of the transmitting / receiving section 120, the transmitting / receiving antenna 130, and the transmission path interface 140.

[0187] The transceiver unit 120 may transmit either information regarding the second reference signal set or information regarding the fourth reference signal set if a third reference signal set for beam failure detection and a fourth reference signal set for candidate beams are supported instead of the first reference signal set for beam failure detection and the second reference signal set for candidate beams, or the first reference signal set and the second reference signal set.

[0188] Alternatively, when the transceiver unit 120 does not provide information regarding the first reference signal set and information regarding the third reference signal set, it may receive a report of beam failure based on a reference signal set for beam failure detection determined based on either information regarding the second reference signal set or information regarding the fourth reference signal set.

[0189] The control unit 110 may control the transmission process / reception process in the transmission / reception unit 120 .

[0190] (user terminal) 5 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal 20 may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0191] Note that this example mainly shows functional blocks of the characteristic parts of the present embodiment, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0192] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0193] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may also control transmission and reception, measurement, etc. using the transceiver unit 220 and the transceiver antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 220.

[0194] The transceiver unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may be configured from a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0195] The transmitting / receiving unit 220 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiving unit may be composed of a reception processing unit 2212, an RF unit 222, and a measurement unit 223.

[0196] The transmitting / receiving antenna 230 can be configured as an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0197] The transceiver 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 220 may transmit the above-mentioned uplink channel, uplink reference signal, etc.

[0198] The transceiver 220 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0199] The transceiver 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

[0200] The transceiver 220 (transmission processor 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0201] Whether or not to apply DFT processing may be based on the setting of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the transmission processing to transmit the channel using a DFT-s-OFDM waveform, and when transform precoding is not enabled, the transceiver unit 220 may not perform DFT processing as the transmission processing.

[0202] The transmitting / receiving unit 220 (RF unit 222) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna 230.

[0203] On the other hand, the transmitting / receiving unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna 230.

[0204] The transceiver 220 (reception processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal to acquire user data, etc.

[0205] The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurement, CSI measurement, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

[0206] The transmitting section and receiving section of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving section 220 and the transmitting / receiving antenna 230.

[0207] The transceiver unit 220 may receive either information regarding the second reference signal set or information regarding the fourth reference signal set if a third reference signal set for beam failure detection and a fourth reference signal set for candidate beams are supported instead of a first reference signal set for beam failure detection and a second reference signal set for candidate beams, or the first reference signal set and the second reference signal set.

[0208] When information regarding the first reference signal set and the third reference signal set is not provided, the control unit 210 may determine the reference signal set to be used for beam failure detection based on either the information regarding the second reference signal set or the information regarding the fourth reference signal set.

[0209] When information about the first reference signal set is not provided and information about the second reference signal set is provided, the control unit 210 may determine the first reference signal set based on the first rule.

[0210] When information about the third reference signal set is not provided and information about the fourth reference signal set is provided, the control unit 210 may determine the third reference signal set based on the second rule.

[0211] The third reference signal set may include two reference signal sets, and the fourth reference signal set may include two reference signal sets each associated with the two reference signal sets included in the third reference signal set.

[0212] (Hardware configuration) The block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may also be realized by combining the single device or multiple devices with software.

[0213] Here, the functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission may be called a transmitting unit, transmitter, etc. As mentioned above, the implementation method of each is not particularly limited.

[0214] For example, a base station, a user terminal, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 6 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. The above-described base station 10 and user terminal 20 may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0215] In this disclosure, terms such as apparatus, circuit, device, section, unit, etc. may be read interchangeably. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0216] For example, although only one processor 1001 is shown, there may be multiple processors. Furthermore, processing may be performed by one processor, or processing may be performed by two or more processors simultaneously, serially, or in other ways. Furthermore, processor 1001 may be implemented by one or more chips.

[0217] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading predetermined software (programs) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, control communication via the communication device 1004, and control at least one of reading and writing data in the memory 1002 and the storage 1003.

[0218] The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transmission / reception unit 120 (220), etc. may be realized by the processor 1001.

[0219] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 110 (210) may be realized by a control program stored in the memory 1002 and running on the processor 1001, and the other functional blocks may be realized in a similar manner.

[0220] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, a cache, a main memory, or the like. The memory 1002 may store executable programs (program codes), software modules, and the like for implementing a wireless communication method according to an embodiment of the present disclosure.

[0221] Storage 1003 is a computer-readable recording medium and may be constituted by at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, stick, key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as a secondary storage device.

[0222] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmission / reception unit 120 (220), transmission / reception antenna 130 (230), etc. may be realized by the communication device 1004. The transmission / reception unit 120 (220) may be implemented as a transmission unit 120a (220a) and a reception unit 120b (220b) that are physically or logically separated.

[0223] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0224] Furthermore, each device, such as the processor 1001 and the memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0225] Furthermore, the base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized using such hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0226] (Variation) Note that terms explained in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0227] A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0228] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and may indicate at least one of, for example, a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), the number of symbols per TTI, a radio frame structure, a specific filtering process performed by a transceiver in the frequency domain, and a specific windowing process performed by a transceiver in the time domain.

[0229] A slot may be composed of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol), and may be a time unit based on numerology.

[0230] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (PUSCH) mapping type B.

[0231] A radio frame, a subframe, a slot, a minislot, and a symbol all represent time units for transmitting signals. The radio frame, the subframe, the slot, the minislot, and the symbol may be referred to by other names corresponding to the radio frame, the subframe, the slot, the minislot, and the symbol. Note that the time units such as a frame, a subframe, a slot, a minislot, and a symbol in the present disclosure may be interchangeable.

[0232] For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0233] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. However, the definition of TTI is not limited to this.

[0234] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0235] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0236] A TTI having a time length of 1 ms may be called a regular TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0237] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0238] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0239] In addition, an RB may include one or more symbols in the time domain and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0240] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0241] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0242] A Bandwidth Part (BWP), which may also be referred to as a fractional bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within that BWP.

[0243] The BWP may include an UL BWP (a BWP for UL) and a DL BWP (a BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0244] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0245] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0246] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by a predetermined index.

[0247] The names used for parameters and the like in this disclosure are not intended to be limiting in any way. Furthermore, the mathematical expressions and the like using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0248] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0249] Furthermore, information, signals, etc. may be output from a higher layer to a lower layer and / or from a lower layer to a higher layer. Information, signals, etc. may be input / output via multiple network nodes.

[0250] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0251] Notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, notification of information in the present disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI) and Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB) and System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0252] Note that the physical layer signaling may be called Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. Furthermore, the RRC signaling may be called an RRC message, such as an RRC connection setup message or an RRC connection reconfiguration message. Furthermore, the MAC signaling may be notified using, for example, a MAC Control Element (CE).

[0253] Furthermore, notification of specified information (e.g., notification that "it is X") is not limited to explicit notification, but may be made implicitly (e.g., by not notifying the specified information or by notifying other information).

[0254] The determination may be made by a value represented by one bit (0 or 1), by a Boolean value represented by true or false, or by a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0255] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0256] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0257] As used in this disclosure, the terms "system" and "network" may be used interchangeably. A "network" may refer to devices included in the network (e.g., base stations).

[0258] In the present disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "Quasi-Co-Location (QCL)," "Transmission Configuration Indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," etc. may be used interchangeably.

[0259] In this disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNB (eNodeB)," "gNB (gNodeB)," "access point," "transmission point (TP)," "reception point (RP)," "transmission / reception point (TRP)," "panel," "cell," "sector," "cell group," "carrier," "component carrier," etc. may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0260] 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, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or base station subsystem that provides communication service within this coverage.

[0261] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0262] A mobile station may also be referred to as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0263] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, etc. Note that at least one of the base station and the mobile station may be a device mounted on a moving object, the moving object itself, etc.

[0264] The mobile body is a movable object that can move at any speed and naturally includes cases where the mobile body is stationary. Examples of the mobile body include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcars, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and objects mounted thereon. The mobile body may also be a mobile body that moves autonomously based on an operation command.

[0265] The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Note that at least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0266] 7 is a diagram showing an example of a vehicle according to an embodiment. Vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, an electronic control unit 49, various sensors (including a current sensor 50, an RPM sensor 51, an air pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

[0267] The drive unit 41 is configured with at least one of an engine, a motor, and a hybrid of an engine and a motor, for example. The steering unit 42 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by the user.

[0268] The electronic control unit 49 is composed of a microprocessor 61, memory (ROM, RAM) 62, and a communication port (e.g., an input / output (IO) port) 63. Signals are input to the electronic control unit 49 from various sensors 50-58 provided in the vehicle. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

[0269] The signals from the various sensors 50-58 include a current signal from a current sensor 50 that senses the current of the motor, a rotation speed signal of the front wheels 46 / rear wheels 47 obtained by a rotation speed sensor 51, an air pressure signal of the front wheels 46 / rear wheels 47 obtained by an air pressure sensor 52, a vehicle speed signal obtained by a vehicle speed sensor 53, an acceleration signal obtained by an acceleration sensor 54, a depression amount signal of the accelerator pedal 43 obtained by an accelerator pedal sensor 55, a depression amount signal of the brake pedal 44 obtained by a brake pedal sensor 56, an operation signal of the shift lever 45 obtained by a shift lever sensor 57, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 58.

[0270] The information service unit 59 is composed of various devices, such as a car navigation system, an audio system, speakers, a display, a television, and a radio, for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 59 uses information acquired from external devices via the communication module 60 or the like to provide various information / services (for example, multimedia information / multimedia services) to the occupants of the vehicle 40.

[0271] The information service unit 59 may include input devices (e.g., keyboards, mice, microphones, switches, buttons, sensors, touch panels, etc.) that accept input from the outside, and may also include output devices (e.g., displays, speakers, LED lamps, touch panels, etc.) that output to the outside.

[0272] The driving assistance system unit 64 is configured with various devices that provide functions for preventing accidents and reducing the driver's driving burden, such as millimeter-wave radar, Light Detection and Ranging (LiDAR), cameras, positioning locators (e.g., Global Navigation Satellite System (GNSS)), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyro systems (e.g., Inertial Measurement Units (IMUs), Inertial Navigation Systems (INSs)), Artificial Intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driving assistance functions or autonomous driving functions.

[0273] The communication module 60 can communicate with the microprocessor 61 and components of the vehicle 40 via the communication port 63. For example, the communication module 60 transmits and receives data (information) via the communication port 63 to and from the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and the various sensors 50-58, which are provided in the vehicle 40.

[0274] The communication module 60 is a communication device that can be controlled by the microprocessor 61 of the electronic control unit 49 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 60 may be located either inside or outside the electronic control unit 49. The external device may be, for example, the above-mentioned base station 10 or user terminal 20. Furthermore, the communication module 60 may be, for example, at least one of the above-mentioned base station 10 and user terminal 20 (or may function as at least one of the base station 10 and user terminal 20).

[0275] The communication module 60 may transmit at least one of signals from the above-mentioned various sensors 50-58 input to the electronic control unit 49, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 59 to an external device via wireless communication. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 60 may include information based on the above-mentioned input.

[0276] The communication module 60 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from external devices and displays it on an information service unit 59 provided in the vehicle. The information service unit 59 may also be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH received by the communication module 60 (or data / information decoded from the PDSCH)).

[0277] Furthermore, the communication module 60 stores various information received from external devices in a memory 62 that can be used by the microprocessor 61. Based on the information stored in the memory 62, the microprocessor 61 may control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, various sensors 50-58, and the like provided in the vehicle 40.

[0278] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, terms such as uplink channel and downlink channel may be read as sidelink channel.

[0279] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station 10 may be configured to have the functions of the user terminal 20 described above.

[0280] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME) and a Serving-Gateway (S-GW)), or a combination thereof.

[0281] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the specific order presented.

[0282] Each aspect / embodiment described in the present disclosure may be a technology other than Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (x is, for example, an integer or decimal number)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE The present invention may be applied to systems that use 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other appropriate wireless communication methods, or to next-generation systems that are expanded, modified, created, or defined based on these. It may also be applied to a combination of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0283] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0284] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0285] The term "determining," as used in this disclosure, may encompass a wide variety of actions. For example, "determining" may be considered to be judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., looking up in a table, database, or another data structure), ascertaining, etc.

[0286] Additionally, "determining" may be considered to be "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), etc.

[0287] Also, "decision" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. In other words, "decision" may be considered to be "deciding" on some action.

[0288] Furthermore, "judgment (decision)" may be interpreted as "assuming," "expecting," "considering," or the like.

[0289] As used in this disclosure, the terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access."

[0290] In this disclosure, when two elements are connected, they may be considered to be "connected" or "coupled" to one another using one or more wires, cables, printed electrical connections, etc., as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, etc., as some non-limiting and non-exhaustive examples.

[0291] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0292] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0293] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0294] Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the invention as defined by the description of the claims. Therefore, the description of the present disclosure is intended to be illustrative and explanatory and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. a receiving unit that receives one of second information about the second reference signal set or fourth information about the fourth reference signal set when a third reference signal set for beam failure detection and a fourth reference signal set for candidate beams are supported instead of a first reference signal set for beam failure detection and a second reference signal set for candidate beams, or the first reference signal set and the second reference signal set; A terminal having a control unit that, when first information regarding the first reference signal set and third information regarding the third reference signal set are not provided, determines a reference signal set to be used for beam failure detection based on either the second information or the fourth information.

2. The terminal according to claim 1 , wherein the control unit determines the first reference signal set based on a first rule when the first information is not provided and the second information is provided.

3. The terminal according to claim 1 , wherein the control unit determines the third reference signal set based on a second rule when the third information is not provided and the fourth information is provided.

4. 4. The terminal according to claim 1, wherein the third reference signal set includes two reference signal sets, and the fourth reference signal set includes two reference signal sets respectively associated with the two reference signal sets included in the third reference signal set.

5. receiving one of second information about the second reference signal set or fourth information about the fourth reference signal set when a first reference signal set for beam failure detection and a second reference signal set for a candidate beam, or a third reference signal set for beam failure detection and a fourth reference signal set for a candidate beam, are supported instead of the first reference signal set and the second reference signal set; A wireless communication method for a terminal, comprising: a step of determining a reference signal set to be used for beam failure detection based on either the second information or the fourth information when first information regarding the first reference signal set and third information regarding the third reference signal set are not provided.

6. a transmitter that transmits, when a first reference signal set for beam failure detection and a second reference signal set for a candidate beam, or a third reference signal set for beam failure detection and a fourth reference signal set for a candidate beam, instead of the first reference signal set and the second reference signal set, one of second information regarding the second reference signal set or fourth information regarding the fourth reference signal set; A base station having a receiving unit that, when first information regarding the first reference signal set and third information regarding the third reference signal set are not provided, receives a report of beam failure based on a reference signal set for beam failure detection determined based on either the second information or the fourth information.

7. A system having a terminal and a base station, The terminal a receiving unit that receives one of second information about the second reference signal set or fourth information about the fourth reference signal set when a third reference signal set for beam failure detection and a fourth reference signal set for candidate beams are supported instead of a first reference signal set for beam failure detection and a second reference signal set for candidate beams, or the first reference signal set and the second reference signal set; a control unit that determines a reference signal set to be used for beam failure detection based on one of the second information or the fourth information when first information regarding the first reference signal set and third information regarding the third reference signal set are not provided; The base station A system comprising a transmitter that transmits one of the second information or the fourth information.

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