Terminal, wireless communication method, base station and system

Abstract

A terminal according to an aspect of the present disclosure is characterized by comprising a reception unit that receives a reference signal (RS), and a control unit that, if a single frequency network (SFN) scheme is set and at least one of a radio link monitoring (RLM) RS and a beam failure detection (BFD) RS is not set, selects, as at least one of the RLM RS and the BFD RS, the RS corresponding to a control resource set (CORESET) that is determined on the basis of a particular rule. According to an aspect of the present disclosure, at least one of the RLM and the BFD can be appropriately carried out.

Description

Terminal, wireless communication method and base station

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

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

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

[0004] 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

[0005] In a wireless communication system (e.g., NR), a terminal (user terminal, User Equipment (UE)) performs radio link monitoring (RLM) / beam failure detection (BFD). For RLM / BFD, a reference signal (RS) (RLM-RS / BFD-RS) is used.

[0006] However, in a single frequency network (SFN) environment of a future wireless communication system, if the setting / information elements of the RLM-RS / BFD-RS are not provided, it is unclear how to determine the RLM-RS / BFD-RS. As a result, if the RLM / BFD is not performed appropriately, there is a risk that the throughput will decrease or the communication quality will deteriorate.

[0007] Therefore, one of the objects of the present disclosure is to provide a terminal, a wireless communication method, and a base station that appropriately perform at least one of RLM and BFD.

[0008] A terminal according to one aspect of the present disclosure includes: a receiving unit that receives a reference signal (RS); and a control unit that, when a single frequency network (SFN) scheme is configured and at least one of a radio link monitoring (RLM)-RS and a beam failure detection (BFD)-RS is not configured, selects the RS corresponding to a control resource set (CORESET) determined based on a specific rule as at least one of the RLM-RS and the BFD-RS.

[0009] According to one aspect of the present disclosure, at least one of RLM and BFD can be appropriately performed.

[0010] FIG. 1 is a diagram showing an example of the number of RLM-RSs. FIG. 2 is a diagram showing an example of a beam recovery procedure. FIG. 3 is a flowchart showing an example of a method for selecting RLM-RS / BFD-RS. FIG. 4 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 5 is a diagram showing an example of a configuration of a base station according to an embodiment. FIG. 6 is a diagram showing an example of a configuration of a user terminal according to an embodiment. FIG. 7 is a diagram showing an example of hardware configurations of a base station and a user terminal according to an embodiment. FIG. 8 is a diagram showing an example of a vehicle according to an embodiment.

[0011] (TCI, spatial relationship, QCL) In NR, it is 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 a UE of at least one of a signal and a channel (referred to as a signal / channel) based on a 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 that 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] The QCL is an index indicating the statistical properties of signals / channels. For example, if a signal / channel has a QCL relationship with another signal / channel, it may mean that it can be assumed that at least one of a Doppler shift, a Doppler spread, an average delay, a delay spread, and a spatial parameter (e.g., a spatial Rx parameter) is the same between these different signals / channels (i.e., the signals / channels have a QCL 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 identified based on a spatial QCL. The QCL (or at least one element of the QCL) in the present disclosure may be replaced with sQCL (spatial QCL).

[0016] A plurality of types (QCL types) of QCL may be defined. For example, four QCL types A to D may be provided, each having different parameters (or parameter sets) that can be assumed to be the same. The parameters (which may be referred to as QCL parameters) are as follows: 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 UE's assumption 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 channel of interest (in other words, the Reference Signal (RS) for that 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 tracking CSI-RS (also called a tracking reference signal (TRS)), and a QCL detection reference signal (also called a QRS).

[0023] An SSB is a signal block including 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 QCL type X relationship with a certain channel / signal (DMRS), and this RS may be called a QCL source of QCL type X in the TCI state.

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

[0026] For example, TRS1-1, 1-2, 1-3, and 1-4 are transmitted, and TRS1-1 is notified as a QCL type C / D RS depending on the TCI status of the PDSCH. By notifying 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 the PDSCH. In this case, the QCL source of the PDSCH is TRS1-1, and the QCL target is the DMRS for the PDSCH.

[0027] (Multi-TRP) In NR, one or more transmission / reception points (TRP) (multi-TRP (MTRP)) 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 (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 a multi-TRP may transmit a different code word (CW) and a different layer. Non-Coherent Joint Transmission (NCJT) may be used as a form of multi-TRP transmission.

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

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

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

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

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

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

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

[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. In this case, the TRP may be replaced with the CORESET pool index. [Condition 1] A CORESET pool index of 1 is set. [Condition 2] Two different values ​​of the CORESET pool index (e.g., 0 and 1) are set.

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

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

[0041] In NR, the base station may configure a radio link monitoring reference signal (Radio Link Monitoring RS (RLM-RS)) for each BWP to the UE using higher layer signaling. The UE may receive configuration information for RLM (for example, the RRC "RadioLinkMonitoringConfig" information element).

[0042] The configuration information for the RLM may include fault detection resource configuration information (e.g., the upper layer parameter "failureDetectionResourcesToAddModList") and parameters related to the RLM-RS (e.g., the upper layer parameter "RadioLinkMonitoringRS").

[0043] The parameters related to the RLM-RS may include information indicating correspondence to the purpose of RLM, an index corresponding to the resource of the RLM-RS (e.g., an index included in the upper layer parameter "failureDetectionResources" (RadioLinkMonitoringRS in failureDetectionResourcesToAddModList)), etc. The index may be, for example, an index of the CSI-RS resource configuration (e.g., a non-zero power CSI-RS resource ID) or an SS / PBCH block index (SSB index). The purpose information may indicate a beam failure, a (cell-level) Radio Link Failure (RLF), or both.

[0044] The UE may identify an RLM-RS resource based on an index corresponding to the resource of the RLM-RS, and perform RLM using the RLM-RS resource.

[0045] In Rel. 16 RLM, the UE follows the following procedure:

[0046] [Procedure] If the UE is not provided with a Radio Link Monitoring RS (RLM-RS) and the UE is provided with a TCI state including one or more CSI-RS for PDCCH reception, the UE shall follow steps 1 to 4 below.

[0047] [Procedure 1] If the active TCI state for PDCCH reception includes only one RS, the UE uses the RS provided for the active TCI state for PDCCH reception for RLM. [Procedure 2] If the active TCI state for PDCCH reception includes two RSs, the UE assumes that one RS has QCL type D, and the UE uses the RS with QCL type D for RLM. The UE does not assume that both RSs have QCL type D. [Procedure 3] The UE is not required to use aperiodic or semi-persistent RSs for RLM. [Procedure 4] L max For =4, the UE selects N provided for active TCI states for PDCCH reception in multiple CORESETs associated with multiple search space sets, in order of the smallest monitoring periodicity. RLM If more than one CORESET is associated with multiple search space sets with the same monitoring period, the UE determines the order of the CORESETs from the highest CORESET index.

[0048] where L max is the maximum number of SS / PBCH block indexes in a cell. The maximum number of SS / PBCH blocks transmitted in a half frame is L max is.

[0049] Thus, if the UE is not provided with RLM-RS, the UE makes an implicit RLM-RS decision and uses the active TCI state for PDCCH reception for RLM. max If ≠4, the UE first determines the CORESET in ascending order of the monitoring period of the search space set, then in descending order of the CORESET index, and then determines the N provided for the active TCI state for PDCCH reception in that CORESET. RLM This selection method corresponds to the existing selection method in RLM-RS, which will be described later.

[0050] The UE uses N for link recovery procedures and RLM.LR-RLM Up to N RLM-RSs can be configured. LR-RLM From RLM-RS, L max Depends on N RLM Up to RLM-RSs are used for RLM. In Rel. 16, as shown in Figure 1, max N if =4 RLM = 2, and L max N when =8 RLM = 4, and L max = 64, N RLM =8.

[0051] (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 referred to as a transmit beam, Tx beam, etc.) and a beam used to receive a signal (also referred to as a receive beam, Rx beam, etc.).

[0052] When beamforming is used, it is expected that radio link quality will deteriorate due to increased susceptibility to interference from obstacles. This deterioration in radio link quality may lead to frequent radio link failures (RLFs). Since RLFs require cell reconnection, frequent RLFs will result in degradation of system throughput.

[0053] In NR, in order to suppress the occurrence of RLF, when the quality of a specific beam deteriorates, a procedure for switching to another beam (which may be called Beam Recovery (BR), Beam Failure Recovery (BFR), L1 / L2 (Layer 1 / Layer 2) beam recovery, etc.) is performed. Note that the BFR procedure may also be simply called BFR.

[0054] Note that the beam failure (BF) in this disclosure may also be referred to as a link failure.

[0055] 2 is a diagram showing 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.

[0056] The RS may be at least one of a synchronization signal block (SSB) and a channel state measurement RS (Channel State Information RS (CSI-RS)). The SSB may also be called an SS / PBCH (Physical Broadcast Channel) block.

[0057] 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.

[0058] In step S102, the UE cannot detect the BFD-RS (or the reception quality of the RS deteriorates) due to interference with the radio waves from the base station. Such interference can occur due to, for example, obstacles, fading, interference, etc. between the UE and the base station.

[0059] The UE detects a beam failure when a predetermined condition is satisfied. For example, the UE may detect the occurrence of a beam failure when the block error rate (BLER) is less than a threshold for all configured BFD-RSs (BFD-RS resource configurations). When the occurrence of a beam failure is detected, a lower layer (physical (PHY) layer) of the UE may notify (indicate) a beam failure instance to an upper layer (MAC layer).

[0060] The criteria for the determination are not limited to BLER, but may be Layer 1 Reference Signal Received Power (L1-RSRP) in the physical layer. Also, instead of or in addition to RS measurement, beam failure detection may be performed based on a downlink control channel (Physical Downlink Control Channel (PDCCH)). The BFD-RS may be expected to be quasi-co-located (QCL) with the DMRS of the PDCCH monitored by the UE.

[0061] Here, the QCL is an index indicating the statistical properties of a channel. For example, if a signal / channel has a QCL relationship with another signal / channel, it may mean that it can be assumed that at least one of a Doppler shift, a Doppler spread, an average delay, a delay spread, and a spatial parameter (e.g., a spatial Rx parameter) is the same between these different signals / channels (i.e., the QCL is true for at least one of these).

[0062] The spatial reception parameters may correspond to a reception beam (e.g., a reception analog beam) of the UE, and the beam may be identified based on a spatial QCL. The QCL (or at least one element of the QCL) in the present disclosure may be replaced with sQCL (spatial QCL).

[0063] Information about BFD-RS (e.g., RS index, resource, number, number of ports, precoding, etc.), information about beam failure detection (BFD) (e.g., the above-mentioned threshold), etc. may be configured (notified) to the UE using higher layer signaling, etc. The information about BFD-RS may also be referred to as information about BFR resources, etc.

[0064] When a beam failure instance notification is received from the UE's PHY layer, the UE's upper layer (e.g., MAC layer) may start a predetermined timer (which may be called a beam failure detection timer). If the UE's MAC layer receives a certain number of beam failure instance notifications (e.g., beamFailureInstanceMaxCount configured in RRC) before the timer expires, the UE's MAC layer may trigger a BFR (e.g., start one of the random access procedures described below).

[0065] The base station may determine that the UE has detected a beam failure if there is no notification from the UE or if it receives a predetermined signal (beam recovery request in step S104) from the UE.

[0066] 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 (New Candidate Beam Identification RS (NCBI-RS)), a CBI-RS, or a CB-RS (Candidate Beam RS). The NCBI-RS may be the same as or different from the BFD-RS. Note that the new candidate beam may simply be called a candidate beam or candidate RS.

[0067] 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 NCBI-RSs whose L1-RSRP exceeds a threshold. Note that the criteria for determination are not limited to L1-RSRP. The L1-RSRP related to SSB may be referred to as SS-RSRP. The L1-RSRP related to CSI-RS may be referred to as CSI-RSRP.

[0068] Information about the NCBI-RS (e.g., RS resources, number of ports, precoding, etc.), information about the new candidate beam identification (NCBI) (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 NCBI-RS) may be acquired based on information about the BFD-RS. Information about the NCBI-RS may be referred to as information about NBCI resources, etc.

[0069] Note that BFD-RS, NCBI-RS, etc. may be read as Radio Link Monitoring RS (RLM-RS).

[0070] In step S104, the UE that has identified the new candidate beam transmits a beam failure recovery request (BFRQ). The beam recovery request may also be referred to as a beam recovery request signal, a beam failure recovery request signal, or the like.

[0071] 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.

[0072] 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.

[0073] In Rel. 15 NR, CB-BFR (Contention-Based BFR), which is a BFR based on a contention-based random access (RA) procedure, and CF-BFR (Contention-Free BFR), which is a BFR based on a contention-free random access procedure, are being considered. In CB-BFR and CF-BFR, the UE may use the PRACH resource to transmit a preamble (also referred to as an RA preamble, a random access channel (Physical Random Access Channel (PRACH)), a RACH preamble, etc.) as a BFRQ.

[0074] In CB-BFR, a UE may transmit a preamble randomly selected from one or more preambles. On the other hand, in CF-BFR, a UE may transmit a preamble assigned specifically to the UE by the base station. In CB-BFR, a base station may assign the same preamble to multiple UEs. In CF-BFR, a base station may assign a preamble individually to each UE.

[0075] Note that CB-BFR and CF-BFR may be referred to as CB PRACH-based BFR (contention-based PRACH-based BFR (CBRA-BFR)) and CF PRACH-based BFR (contention-free PRACH-based BFR (CFRA-BFR)), respectively. CBRA-BFR may be referred to as CBRA for BFR. CFRA-BFR may be referred to as CFRA for BFR.

[0076] Regardless of whether CB-BFR or CF-BFR is used, information about the PRACH resource (RA preamble) may be notified, for example, by higher layer signaling (such as RRC signaling). For example, the information may include information indicating a correspondence relationship between the detected DL-RS (beam) and the PRACH resource, and a different PRACH resource may be associated with each DL-RS.

[0077] In step S105, the base station that detected the BFRQ transmits a response signal (which may be referred to as a gNB response, etc.) to the BFRQ from the UE. The response signal may include reconfiguration information (e.g., DL-RS resource configuration information) for one or more beams.

[0078] The response signal may be transmitted, for example, in a UE common search space of the PDCCH. The response signal may be signaled using a PDCCH (DCI) scrambled with a cyclic redundancy check (CRC) by a UE identifier (e.g., a Cell-Radio RNTI (C-RNTI)). The UE may determine at least one of a transmit beam and a receive beam to use based on the beam reconfiguration information.

[0079] 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.

[0080] For CB-BFR, contention resolution may be determined to be successful if the UE receives a PDCCH corresponding to its own C-RNTI.

[0081] Regarding the processing of step S105, a period for the UE to monitor a response from a base station (e.g., a gNB) to the BFRQ may be set. This period may be referred to as, for example, a gNB response window, a gNB window, a beam recovery request response window, etc. If no gNB response is detected within this window period, the UE may retransmit the BFRQ.

[0082] 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.

[0083] 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.

[0084] Rel. 15 supports the use of a random access procedure to perform a beam recovery procedure (e.g., BFRQ notification) for a beam failure detected in an SpCell (PCell / PSCell). On the other hand, Rel. 16 supports the use of at least one of a PUCCH (e.g., a scheduling request (SR)) transmission for BFR and a MAC CE (e.g., an UL-SCH) transmission for BFR to perform a beam recovery procedure (e.g., BFRQ notification) for a beam failure detected in an SCell.

[0085] For example, the UE may transmit information about beam failure using a MAC CE-based two-step method, which may include information about the cell that detected the beam failure and information about a new candidate beam (or a new candidate RS index).

[0086] [Step 1] If a BFR is detected, a PUCCH-BFR (scheduling request (SR)) may be transmitted from the UE to the PCell / PSCell. Then, an UL grant (DCI) for the following step 2 may be transmitted from the PCell / PSCell to the UE. If a beam failure is detected and a MAC CE (or an UL-SCH) for transmitting information about a new candidate beam exists, step 1 (e.g., PUCCH transmission) may be omitted and step 2 (e.g., MAC CE transmission) may be performed.

[0087] [Step 2] Next, the UE may transmit information about the cell where beam failure was detected (failed) (e.g., cell index) and information about the new candidate beam to the base station (PCell / PSCell) via an uplink channel (e.g., PUSCH) using a MAC CE. After that, through the BFR procedure, the QCL of the PDCCH / PUCCH / PDSCH / PUSCH may be updated to the new beam after a predetermined period (e.g., 28 symbols) after receiving a response signal from the base station.

[0088] Note that the numbers of these steps are for illustrative purposes only, and multiple steps may be combined or the order may be reversed. Furthermore, whether to perform BFR may be configured in the UE using higher layer signaling.

[0089] (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 the failure detection resources (failureDetectionResources, failureDetectionResourcesToAddModList, RadioLinkMonitoringConfig) and at least one set of P-CSI-RS resource configuration indices and SS / PBCH block indices (q1) via the candidate beam RS list (candidateBeamRSList) or the extended candidate beam RS list (candidateBeamRSListExt-r16) or the candidate beam RS list for SCell (candidateBeamRSSCellList-r16).

[0090] 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.

[0091] The set of P-CSI-RS resources q0 provided by the failure detection resources may be referred to as explicit BFD-RS.

[0092] 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.

[0093] In the present disclosure, providing the above-described higher layer parameters indicating information on indexes corresponding to BFD resources may be interchangeable with configuring BFD resources, configuring a BFD-RS, etc. In the present disclosure, the BFD resources, the periodic CSI-RS resource configuration index or the set of SSB indices q0, the BFD-RS, the BFD-RS set, and the RS set may be interchangeable.

[0094] If the UE is not provided with q0 by the failure detection resources (failureDetectionResources) for one BWP of its serving cell, it determines to include in set q0 a P-CSI-RS resource configuration index having the same value as an RS index in the RS set indicated by the TCI-State (TCI-State) for the corresponding CORESET that the UE uses for PDCCH monitoring. If there are two RS indices in one TCI state, set q0 includes the RS index with QCL type D configuration for the corresponding TCI state. The UE assumes that set q0 includes up to two RS indices. The UE assumes single-port RSs in set q0. This method corresponds to the existing selection method for BFD-RSs, described below.

[0095] This set q0 may be called the implicit BFD-RS.

[0096] In this way, the UE determines the BFD-RS (RS set) according to the TCI state for the PDCCH. The UE assumes that the RS set includes up to two RSs.

[0097] In Rel. 17, if a UE is not provided with q0, it may reuse the RLM-RS selection rule if the number of TCI states in the CORESET associated with the CORESET pool index (CORESETPoolIndex) exceeds the UE capability value for the maximum number of BFD-RS resources per set, i.e., in this case, the above RLM procedures 1 to 4 may be applied to BFD / BFR.

[0098] (SFN PDCCH) For PDCCH / CORESET as defined in Rel. 15, one TCI state without CORESET pool index (also referred to as TRP Info) is set to one CORESET.

[0099] Regarding the PDCCH / CORESET enhancements specified in Rel. 16, in multi-TRP based on multi-DCI, a CORESET pool index is configured for each CORESET.

[0100] In Rel. 17 and later, the following enhancements 1 and 2 regarding PDCCH / CORESET are being considered.

[0101] In the case where multiple antennas (small antennas, transmission / reception points) having the same cell ID form a single frequency network (SFN), up to two TCI states can be set / activated for one CORESET by higher layer signaling (RRC signaling / MAC CE) (Enhancement 1). SFN contributes to at least one of the operation and reliability improvement of HST (high speed train).

[0102] Furthermore, in repeated transmission of PDCCH (which may simply be referred to as "repetition"), two PDCCH candidates in two search space sets are linked, and each search space set is associated with a corresponding CORESET (Enhancement 2). The two search space sets may be associated with the same or different CORESETs. For one CORESET, one (maximum one) TCI state can be configured / activated by higher layer signaling (RRC signaling / MAC CE).

[0103] If two search space sets are associated with different CORESETs with different TCI states, this may mean a multi-TRP repeat transmission. If two search space sets are associated with the same CORESET (CORESET with the same TCI state), this may mean a single-TRP repeat transmission.

[0104] (HST) In LTE, placement of HST (high-speed train) in tunnels is difficult. Large antennas transmit both inside and outside the tunnel. For example, the transmission power of a large antenna is approximately 1 to 5 W. For handover purposes, it is important for the UE to transmit outside the tunnel before entering it. For example, the transmission power of a small antenna is approximately 250 mW. Multiple small antennas (transmitting and receiving points) with the same cell ID and a distance of 300 m form a single frequency network (SFN). All small antennas within the SFN transmit the same signal at the same time on the same PRB. It is assumed that a terminal transmits and receives signals to a single base station. In reality, multiple transmitting and receiving points transmit the same DL signal. When moving at high speed, transmitting and receiving points of several kilometers apart form a single cell. Handover occurs when crossing cells. This reduces the frequency of handovers.

[0105] In NR, it is assumed that a beam transmitted from a transmission point (for example, a remote radio head (RRH)) is used to communicate with a terminal (hereinafter also referred to as a UE) included in a moving object (high speed train (HST)) such as a train moving at high speed. Existing systems (for example, Rel. 15) support transmitting a unidirectional beam from a remote radio head (RRH) to communicate with a moving object.

[0106] For HST / URLLC, SFN scheme A (scheme 1) and SFN scheme B (TRP compensation scheme, TRP pre-compensation scheme) are under consideration for Rel. 17. In scheme A, TRS may be transmitted TRP-specific (using different time / frequency resources depending on the TRP). In SFN scheme A, two TRS resources may be configured for the HST traveling direction and the opposite direction. SFN scheme B may be interpreted as Doppler shift correction, Doppler compensation, pre-Doppler compensation, network (NW) pre-compensation scheme (NW pre-compensation scheme, HST NW pre-compensation scheme, or TRP-based pre-compensation scheme).

[0107] (Analysis) However, in an SFN environment of future wireless communication systems (e.g., Rel. 17 and later), if the configuration / information elements for RLM-RS / BFD-RS are not provided, it is unclear how to determine the RLM-RS / BFD-RS. If the RLM-RS / BFD-RS cannot be determined appropriately, RLM / BFD may not be performed appropriately, which may result in a decrease in throughput or a deterioration in communication quality. Therefore, the present inventors have conceived of a terminal that appropriately performs at least one of RLM and BFD.

[0108] 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.

[0109] In the present disclosure, "A / B" and "at least one of A and B" may be interpreted interchangeably. Also, in the present disclosure, "A / B / C" may mean "at least one of A, B, and C."

[0110] In the present disclosure, terms such as activate, deactivate, indicate (or indicate), select, configure, update, and determine may be read interchangeably. In the present disclosure, terms such as support, control, controllable, operate, and operate may be read interchangeably.

[0111] In the present disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher layer parameters, information elements (IEs), settings, etc. may be interchangeable. In the present disclosure, Medium Access Control (MAC) control elements (CEs), update commands, activation / deactivation commands, etc. may be interchangeable.

[0112] In the present disclosure, higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, etc., or a combination thereof.

[0113] In the present disclosure, MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. 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.

[0114] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0115] In the present disclosure, the terms index, identifier (ID), indicator, resource ID, etc. may be interchangeable. In the present disclosure, the terms sequence, list, set, group, cluster, subset, etc. may be interchangeable.

[0116] In the present disclosure, 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 of QCL type D for TCI state / QCL assumption, RS of QCL type A for 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 read interchangeably. In the present disclosure, QCL type X-RS, DL-RS associated with QCL type X, DL-RS having QCL type X, source of DL-RS, SSB, CSI-RS, and SRS may be read interchangeably.

[0117] In the present disclosure, panel, Uplink (UL) transmitting entity, TRP, spatial relationship, control resource set (CONTROLLER RESOLUTION 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), 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 Associated ID, CORESET Pool Index, the position of one of two TCI states corresponding to one code point of a field in a DCI (ordinal number, first TCI state or second TCI state), and TRP may be read interchangeably.

[0118] In the present disclosure, the terms TRP, transmission point, panel, DMRS port group, CORESET pool, and one of two TCI states associated with one code point in the TCI field may be read interchangeably.

[0119] In this disclosure, the terms "single TRP," "single TRP system," "single TRP transmission," and "single PDSCH" may be interchangeable. In this disclosure, the terms "multiple TRP," "multiple TRP system," "multiple TRP transmission," and "multiple PDSCH" may be interchangeable. In this disclosure, the terms "single DCI," "single PDCCH," "multiple TRP based on a single DCI," and "activating two TCI states on at least one TCI codepoint" may be interchangeable.

[0120] In the present disclosure, single TRP, channel using single TRP, channel using one TCI state / spatial relationship, multi-TRP not enabled by RRC / DCI, multiple TCI states / spatial relationships not enabled by RRC / DCI, a CORESETPoolIndex value of 1 not set for any CORESET, and no code point in the TCI field mapped to two TCI states may be read interchangeably.

[0121] In the present disclosure, "multi-TRP," "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, "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, "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.

[0122] 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, and 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.

[0123] In the present disclosure, the terms pool, set, group, and list may be read interchangeably.

[0124] In this disclosure, the notation "Rel. XX" indicates a 3GPP release. However, the release number "XX" is an example and may be replaced with another number.

[0125] An SFN-CORESET, a CORESET that is an SFN (corresponding to an SFN), and a CORESET that has two active TCI states may be interchangeable. A non-SFN-CORESET, a CORESET that is not an SFN (not corresponding to an SFN), and a CORESET that has one active TCI state may be interchangeable. In the present disclosure, the terms "select" and "determine" may be interchangeable. In the present disclosure, the terms "BFR" and "BFD" may be interchangeable.

[0126] (Wireless communication method) In an SFN environment, it is important to determine two RLM-RS / BFD-RS corresponding to two active TCIs of a CORESET in the SFN. In an SFN environment, it is assumed that PDCCH / PDSCH is received in the SFN. Therefore, even when determining the RLM-RS / BFD-RS (when the RLM-RS / BFD-RS is not explicitly provided / configured), even if both an SFN-CORESET (a CORESET corresponding to two active TCI states) and a non-SFN-CORESET (a CORESET corresponding to one active TCI state) are configured, by using the RLM-RS / BFD-RS selected in the SFN-CORESET, RLM / BFD can be more appropriately performed in an SFN scenario. Hereinafter, a method for selecting an RLM-RS / BFD-RS will be described.

[0127] When a UE receives a reference signal (RS), an SFN scheme is configured, and an RLM-RS / BFD-RS is not configured, the UE may select an RS corresponding to a CORESET determined based on a specific rule as the RLM-RS / BFD-RS. The selection method will be specifically described below.

[0128] 3 is a flowchart showing an example of a method for selecting an RLM-RS / BFD-RS. When the SFN scheme A / B is configured in the UE (YES in step S201) and an RLM-RS / BFD-RS is not configured (NO in step S202), the UE determines a CORESET based on a specific rule (step S203). Then, the UE selects an RS corresponding to the CORESET as the RLM-RS / BFD-RS (step S204).

[0129] If the SFN scheme A / B is not configured (NO in step S201), the RLM-RS / BFD-RS may be selected according to an existing selection method (for example, the method of Rel. 15 / 16). Furthermore, the configuration of the SFN scheme A / B (YES in step S201) may be interpreted as the configuration of the SFN scheme A / B in the PDCCH, or the configuration of an RLM-RS / BFD-RS selection rule for SFN.

[0130] In step S204, the UE determines N TCI states provided for active TCI states for PDCCH reception in the CORESET determined in step S203. RLM N RLM-RSs may be selected. RLM may be the same as or different from the value in Rel. 16 described above.

[0131] In step S204, the UE may decide to include in set q0 (BFD-RS) a P-CSI-RS resource configuration index that has the same value as the RS index in the RS set indicated by the TCI-State for the CORESET determined in step S203, which is used for monitoring the PDCCH.

[0132] The specific rule in step S203 may be the same as or different from the rule in the existing RLM-RS / BFD-RS selection method, and may include a condition that the CORESET is an SFN (SFN-CORESET) or is not an SFN (non-SFN-CORESET).

[0133] Examples of specific rules will be described below. In step S103, the UE may apply specific rules to multiple CORESETs in the following order: (1), (2), and (3), and determine the CORESET with the highest priority. The order in which (1), (2), and (3) are applied can be changed as appropriate. For example, the UE may apply the rules in the order: (1), (3), and (2); (2), (1), and (3); (2), (3), and (1); (3), (1), and (2); or (3), (2), and (1) to determine the CORESET.

[0134] [Specific rules] (1) An SFN-CORESET is determined with priority over a non-SFN-CORESET. Or, a non-SFN-CORESET is determined with priority over an SFN-CORESET. (2) A CORESET with a short (or long) monitoring period of the corresponding search space set is determined with priority. In other words, the UE determines a CORESET in ascending (or descending) order of the monitoring period of the corresponding search space set. (3) A CORESET with a large (or small) CORESET ID is determined with priority. In other words, the UE determines a CORESET in descending (or ascending) order of the CORESET ID.

[0135] If the number of RSs determined by the specific rule (the number of active TCITCI states of the determined CORESET) is 2, the UE may perform RLM / BFD using both RSs, or may perform RLM / BFD using either of the two RSs.

[0136] The UE may determine the specific number of RLM-RSs / BFD-RSs based on the CORESET determined by the specific rule. The specific number may be defined in a specification or may be set according to a value reported as UE capability. The UE may also set the specific number by higher layer signaling / physical layer signaling. The specific number may be different for each RLM-RS / BFD-RS or may be a common value. The specific number may use a value from an existing specification (e.g., Rel. 15 / 16), or may be separately specified / configured in the UE for the RLM-RS / BFD-RS selection rule for SFN, or may be reported by the UE.

[0137] As a method of counting RLM-RS / BFD-RS, when the number of RSs determined using the above specific rule (the number of active TCI states in the determined CORESET) is 2, the number of RSs to be measured is 2, so the number of RLM-RS / BFD-RS may be counted as "2." Alternatively, when the number of RSs determined using the above specific rule (the number of active TCI states in the determined CORESET) is 2, the corresponding number of CORESETs is 1, so the number of RLM-RS / BFD-RS may be counted as "1."

[0138] The RLM-RS selection method and the BFD-RS selection method may be different or may be the same. In the RLM-RS selection method, for a CORESET indicated with two TCI states, RSs corresponding to both TCI states may be used as the RLM-RS. The UE may determine the RLM-RS / BFD-RS taking into account the number of active TCI states of the CORESET.

[0139] <Others> The UE may transmit (report) UE capability information indicating whether it supports at least one of the examples in the present disclosure to the network (base station). The UE may also receive an instruction / configuration (e.g., an instruction / configuration regarding enablement / disablement) regarding at least one of the examples in the present disclosure via higher layer signaling / physical layer signaling. The instruction / configuration may correspond to the UE capability information transmitted by the UE. At least one of the examples in the present disclosure may be applied only to a UE that has received the instruction / configuration, a UE that has transmitted the corresponding UE capability information, or a UE that supports the corresponding UE capability.

[0140] A UE may transmit, as UE capability information, whether it supports the RLM-RS / BFD-RS selection method (e.g., FIG. 3) for SFN schemes A / B in the present disclosure. Note that a UE that does not report (does not support) the selection method as capability information may select an RLM-RS / BFD-RS using an existing selection method (method of Rel. 15 / 16).

[0141] The UE may report whether it supports the BFD-RS selection method and whether it supports the RLM-RS individually, or may report them using common parameters.

[0142] The RLM-RS / BFD-RS selection method of the present disclosure may be applied only to UEs configured with an RLM-RS / BFD-RS selection method for SFN schemes A / B. UEs that are not configured with this selection method may select an RLM-RS / BFD-RS using an existing selection method (the method of Rel. 15 / 16).

[0143] The UE may set the parameters relating to the method for selecting a BFD-RS and the parameters relating to the method for selecting an RLM-RS as separate parameters or as common parameters.

[0144] According to the present disclosure, since RLM-RS / BFD-RS can be appropriately selected, at least one of RLM and BFD can be appropriately performed.

[0145] (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.

[0146] 4 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).

[0147] 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.

[0148] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (Master Node (MN)), and the NR base station (gNB) is the secondary node (Secondary Node (SN)). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0149] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity in which both the MN and SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0150] 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.

[0151] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CCs) and dual connectivity (DC).

[0152] Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band higher than 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a higher frequency band than FR2.

[0153] 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.

[0154] The multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with the Common Public Radio Interface (CPRI), an X2 interface, etc.) or wirelessly (e.g., NR communication). For example, when NR communication is used as a backhaul between the base stations 11 and 12, the base station 11 corresponding to the upper station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0155] 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.

[0156] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0157] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the wireless communication system 1. For example, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), or the like may be used in at least one of the downlink (DL) and uplink (UL).

[0158] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (e.g., other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0159] 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.

[0160] Furthermore, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), or the like may be used as an uplink channel.

[0161] The PDSCH transmits user data, higher layer control information, a System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit a Master Information Block (MIB).

[0162] 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.

[0163] Note that the DCI for scheduling the PDSCH may be referred to as a DL assignment, a DL DCI, etc., and the DCI for scheduling the PUSCH may be referred to as a UL grant, a UL DCI, etc. Note that the PDSCH may be replaced with DL data, and the PUSCH may be replaced with UL data.

[0164] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources for searching for DCI. The search space corresponds to a search region and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor the CORESET associated with a certain search space based on the search space configuration.

[0165] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be referred to as a search space set. Note that the terms "search space," "search space set," "search space configuration," "search space set configuration," "CORESET," "CORESET configuration," and the like in the present disclosure may be read interchangeably.

[0166] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), delivery confirmation information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0167] 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.

[0168] In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, as the DL-RS, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted.

[0169] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including an SS (PSS, SSS) and a PBCH (and a DMRS for the PBCH) may be referred to as an SS / PBCH block, an SS Block (SSB), or the like. Note that the SS, SSB, and the like may also be referred to as a reference signal.

[0170] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), or the like may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may also be called a user equipment-specific reference signal (UE-specific reference signal).

[0171] (Base Station) Fig. 5 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.

[0172] 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.

[0173] 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.

[0174] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurement, etc. The control unit 110 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 120. The control unit 110 may perform call processing (setting up, releasing, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0175] 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.

[0176] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or may be configured from a transmitting unit and a receiving unit. The transmitting unit may be configured from a transmission processing unit 1211 and an RF unit 122. The receiving unit may be configured from a reception processing unit 1212, the RF unit 122, and a measurement unit 123.

[0177] The transmitting and receiving antenna 130 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0178] 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.

[0179] The transceiver 120 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0180] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0181] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0182] The transceiver unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 130.

[0183] 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 130.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] The transmitter and receiver of the base station 10 in the present disclosure may be configured by at least one of the transmitter / receiver 120, the transmitter / receiver antenna 130, and the transmission path interface 140.

[0188] The transceiver 120 may transmit a reference signal (RS). When the control unit 110 configures a single frequency network (SFN) scheme and does not configure at least one of a radio link monitoring (RLM)-RS and a beam failure detection (BFD)-RS, the control unit 110 selects the RS corresponding to a control resource set (CORESET) determined based on a specific rule as at least one of the RLM-RS and the BFD-RS, and controls at least one of the RLM and the BFD using at least one of the selected RLM-RS and the BFD-RS.

[0189] (User Terminal) Fig. 6 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0190] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0191] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured from a controller, a control circuit, etc., which are described based on common understanding in the technical field to which the present disclosure relates.

[0192] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may control transmission and reception, measurement, etc. using the transceiver unit 220 and the transceiver antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals and transfer them to the transceiver unit 220.

[0193] The transceiver unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0194] 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.

[0195] The transmitting / receiving antenna 230 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0196] 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.

[0197] The transceiver unit 220 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0198] The transceiver unit 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

[0199] The transmitter / receiver unit 220 (transmission processing unit 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0200] Whether or not to apply DFT processing may be based on the setting of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the transmission processing to transmit the channel using a DFT-s-OFDM waveform, and if not, it may not be necessary to perform DFT processing as the transmission processing.

[0201] The transceiver unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 230.

[0202] On the other hand, the transceiver unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 230.

[0203] The transceiver unit 220 (reception processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, and acquire user data, etc.

[0204] The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurements, CSI measurements, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

[0205] The transmitting unit and receiving unit of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving unit 220 and the transmitting / receiving antenna 230.

[0206] The transceiver 220 may receive a reference signal (RS). When a single frequency network (SFN) scheme is configured and at least one of a radio link monitoring (RLM)-RS and a beam failure detection (BFD)-RS is not configured, the control unit 210 may select the RS corresponding to a control resource set (CORESET) determined based on a specific rule as at least one of the RLM-RS and the BFD-RS.

[0207] The specific rule may include determining a CORESET corresponding to an SFN preferentially over a CORESET that does not correspond to an SFN. The specific rule may include determining a CORESET having a shorter monitoring period of a corresponding search space set preferentially. The specific rule may include determining a CORESET having a larger CORESET ID preferentially.

[0208] (Hardware Configuration) Note that the block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may be realized by combining software with the single device or the multiple devices.

[0209] Here, the functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission may be called a transmitting unit, transmitter, etc. As described above, the implementation method of each is not particularly limited.

[0210] 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. 7 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.

[0211] In the present disclosure, the terms apparatus, circuit, device, section, unit, etc. may be used interchangeably. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0212] 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.

[0213] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading specified software (programs) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, control communication via the communication device 1004, and control at least one of reading and writing data in the memory 1002 and the storage 1003.

[0214] The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transceiver unit 120 (220), etc. may be realized by the processor 1001.

[0215] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 110 (210) may be implemented by a control program stored in the memory 1002 and running on the processor 1001, and the other functional blocks may be implemented in a similar manner.

[0216] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EEPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, cache, main memory, etc. The memory 1002 may store executable programs (program codes), software modules, etc. for implementing a wireless communication method according to an embodiment of the present disclosure.

[0217] Storage 1003 is a computer-readable recording medium and may be composed of at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, a stick, a key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as an auxiliary storage device.

[0218] 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.

[0219] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0220] 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.

[0221] Furthermore, the base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized using this hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0222] (Modifications) Note that terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0223] 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.

[0224] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and may indicate at least one of, for example, Subcarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, Transmission Time Interval (TTI), number of symbols per TTI, radio frame structure, specific filtering performed by a transceiver in the frequency domain, and specific windowing performed by a transceiver in the time domain.

[0225] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol) in the time domain. A slot may also be a time unit based on numerology.

[0226] 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.

[0227] 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.

[0228] For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc. instead of a subframe.

[0229] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. Note that the definition of TTI is not limited to this.

[0230] 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.

[0231] 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.

[0232] 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.

[0233] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and greater than or equal to 1 ms.

[0234] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may be determined based on numerology.

[0235] In addition, an RB may include one or more symbols in the time domain and may have a length of one slot, one minislot, one subframe, or one TTI, each of which may be composed of one or more resource blocks.

[0236] In addition, one or more RBs may be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0237] 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.

[0238] A Bandwidth Part (BWP), which may also be referred to as a partial bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a Common Reference Point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0239] The BWP may include a UL BWP (BWP for UL) and a DL BWP (BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0240] 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."

[0241] 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.

[0242] 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.

[0243] 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.

[0244] 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.

[0245] 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.

[0246] 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.

[0247] The notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information in the present disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI) and Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB) and System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0248] Note that the physical layer signaling may be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. Furthermore, the RRC signaling may be referred to as an RRC message, such as an RRC Connection Setup message or an RRC Connection Reconfiguration message. Furthermore, the MAC signaling may be notified using, for example, a MAC Control Element (CE).

[0249] 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).

[0250] 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).

[0251] 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.

[0252] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), these wired and / or wireless technologies are included within the definition of transmission media.

[0253] 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).

[0254] 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.

[0255] In the present disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNB (eNodeB)," "gNB (gNodeB)," "access point," "transmission point (TP)," "reception point (RP)," "transmission / reception point (TRP)," "panel," "cell," "sector," "cell group," "carrier," "component carrier," etc. may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0256] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be partitioned into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication service within that coverage.

[0257] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0258] 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.

[0259] 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.

[0260] 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.

[0261] 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.

[0262] 8 is a diagram showing an example of a vehicle according to an embodiment. The vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, an electronic control unit 49, various sensors (including a current sensor 50, an RPM sensor 51, an air pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

[0263] The drive unit 41 is configured with at least one of an engine, a motor, and a hybrid of an engine and a motor, for example. The steering unit 42 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by a user.

[0264] The electronic control unit 49 is composed of a microprocessor 61, memory (ROM, RAM) 62, and a communication port (for example, an input / output (IO) port) 63. Signals are input to the electronic control unit 49 from various sensors 50-58 provided in the vehicle. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

[0265] 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.

[0266] The information service unit 59 is composed of various devices, such as a car navigation system, an audio system, speakers, a display, a television, and a radio, for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 59 uses information acquired from external devices via the communication module 60 or the like to provide various information / services (e.g., multimedia information / multimedia services) to the occupants of the vehicle 40.

[0267] 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.

[0268] The driving assistance system unit 64 includes various devices for providing functions to prevent accidents and reduce the driver's driving burden, such as millimeter-wave radar, Light Detection and Ranging (LiDAR), cameras, positioning locators (e.g., Global Navigation Satellite System (GNSS)), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyro systems (e.g., Inertial Measurement Units (IMUs), Inertial Navigation Systems (INSs)), artificial intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driving assistance functions or autonomous driving functions.

[0269] 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.

[0270] The communication module 60 is a communication device that can be controlled by the microprocessor 61 of the electronic control unit 49 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 60 may be located either inside or outside the electronic control unit 49. The external device may be, for example, the base station 10 or the user terminal 20 described above. Furthermore, the communication module 60 may be, for example, at least one of the base station 10 and the user terminal 20 described above (or may function as at least one of the base station 10 and the user terminal 20).

[0271] 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.

[0272] The communication module 60 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from an external device and displays it on an information service unit 59 provided in the vehicle. The information service unit 59 may also be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH received by the communication module 60 (or data / information decoded from the PDSCH)).

[0273] 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.

[0274] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, terms such as an uplink channel and a downlink channel may be read as a sidelink channel.

[0275] 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.

[0276] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc.), or a combination thereof.

[0277] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0278] Each aspect / embodiment described in the present disclosure may be a technology other than Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (x is, for example, an integer or decimal number)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.17 (WiMAX (registered trademark)), IEEE 802.19 (WiMAX (registered trademark)), IEEE 802.20 (WiMAX (registered trademark)), IEEE 802.21 (Wi-Fi (registered trademark)), IEEE 802.22 (WiMAX (registered trademark)), IEEE 802.23 (WiMAX (registered trademark)), IEEE 802.24 (WiMAX (registered trademark)), IEEE 802.25 (WiMAX (registered trademark)), IEEE 802.26 (WiMAX (registered trademark)), IEEE 802.27 (WiMAX (registered trademark)), IEEE 802.28 (WiMAX (registered trademark)), IEEE 802.29 (WiMAX (registered trademark)), IEEE 802.30 (WiMAX (registered trademark)), IEEE 802.31 (Wi-Fi (registered trademark)), IEEE 802.32 (WiMAX (registered trademark)), IEEE 802.33 (WiMAX (registered trademark)), IEEE 802. The present invention may be applied to systems that use IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other suitable wireless communication methods, or to next-generation systems that are expanded, modified, created, or defined based on these. Furthermore, the present invention may be applied to a combination of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0279] 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."

[0280] 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.

[0281] 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.

[0282] 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.

[0283] Also, "determination" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. In other words, "determination" may be considered to be "deciding" some action.

[0284] Furthermore, "judgment (decision)" may be read as "assuming," "expecting," "considering," or the like.

[0285] 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."

[0286] 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.

[0287] 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."

[0288] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0289] 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.

[0290] 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 receiver that receives setting information for radio link monitoring (RLM) and an RLM-reference signal (RS) based on the setting information; A control unit that selects, when a single frequency network (SFN) scheme is configured and the RLM-RS is not configured, an RS corresponding to a control resource set (CORESET) determined based on a specific rule as the RLM-RS; A terminal having:

2. The specific rule includes that a CORESET having a short monitoring period of a corresponding search space set is preferentially determined. The terminal according to claim 1 .

3. The specific rule includes that a CORESET having a larger CORESET ID is given priority. The terminal according to claim 1 or claim 2.

4. The setting information includes information on the purpose of the RLM. A terminal according to any one of claims 1 to 3.

5. A step of receiving configuration information for radio link monitoring (RLM) and an RLM-reference signal (RS) based on the configuration information; When a single frequency network (SFN) scheme is configured and the RLM-RS is not configured, selecting an RS corresponding to a control resource set (CORESET) determined based on a specific rule as the RLM-RS; A wireless communication method for a terminal having the above configuration.

6. A transmitter that transmits setting information for radio link monitoring (RLM) and an RLM-reference signal (RS) based on the setting information; A control unit that configures a single frequency network (SFN) scheme and, when the RLM-RS is not configured, selects an RS corresponding to a control resource set (CORESET) determined based on a specific rule as the RLM-RS and controls the RLM using the selected RLM-RS; A base station having

7. A system including a terminal and a base station, The terminal a receiving unit that receives configuration information for radio link monitoring (RLM) and an RLM-reference signal (RS) based on the configuration information; A control unit that selects, when a single frequency network (SFN) scheme is configured and the RLM-RS is not configured, an RS corresponding to a control resource set (CORESET) determined based on a specific rule as the RLM-RS; The base station A system having a transmitter that transmits the RLM-RS.