Terminal, wireless communication method, base station, and system

Abstract

A terminal according to one aspect of the present disclosure has: a control unit which, on the basis of an event pertaining to at least one of a plurality of beams, controls at least one of first beam reporting not based on the event and second beam reporting based on the event; and a transmission unit which, when performing the second beam reporting, transmits at least one element from among a random access channel related to first information pertaining to a novel candidate beam, and a medium access control (MAC) control element containing second information pertaining to the novel candidate beam. According to one aspect of the present disclosure, it is possible to appropriately perform beam reporting based on an event.

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 future wireless communication systems, it is being considered that terminals will perform beam reporting based on events.

[0006] However, the conditions for the event and the method for reporting a beam based on the event are not clear. If the conditions for the event and the method for reporting a beam based on the event are not clarified, there is a risk that communication throughput will decrease and overhead will increase.

[0007] Therefore, one of the objectives of the present disclosure is to provide a terminal, a wireless communication method, and a base station that appropriately perform beam reporting based on an event.

[0008] A terminal according to one aspect of the present disclosure has a control unit that controls at least one of a first beam report that is not based on an event related to at least one of a plurality of beams and a second beam report that is based on the event, and a transmission unit that, when making the second beam report, transmits at least one of a random access channel associated with first information related to a new candidate beam and a Medium Access Control (MAC) control element that includes second information related to the new candidate beam.

[0009] According to one aspect of the present disclosure, event-based beam reporting can be performed appropriately.

[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. FIGS. 3A and 3B are diagrams showing an example of beam reporting by multiple UEs. FIG. 4 is a diagram showing an example of a serving beam and an adjacent beam. FIGS. 5A and 5B are diagrams showing an example of beam comparison according to embodiments 1-2. FIG. 6 is a diagram showing an example of a beam reporting according to embodiments 1-3. FIG. 7 is a diagram showing an example of a MAC CE configuration according to embodiment 2-2. FIG. 8 is a diagram showing another example of a MAC CE configuration according to embodiment 2-2. FIGS. 9A and 9B are diagrams showing an example of an event occurrence timeline according to a fourth embodiment. FIGS. 10A and 10B are diagrams showing another example of an event occurrence timeline according to the fourth embodiment. FIG. 11 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 12 is a diagram showing an example of a base station configuration according to an embodiment. FIG. 13 is a diagram showing an example of a user terminal configuration according to an embodiment. FIG. 14 is a diagram showing an example of hardware configurations of a base station and a user terminal according to an embodiment.

[0011] (CSI Reporting) In Rel. 15 / 16 NR, a UE measures a channel state using a predetermined reference signal (or a resource for the reference signal) and feeds back (reports) channel state information (CSI) to a base station.

[0012] The UE may measure the channel state using a Channel State Information-Reference Signal (CSI-RS), a Synchronization Signal / Physical Broadcast Channel (SS / PBCH) block, a Synchronization Signal (SS), a Demodulation Reference Signal (DMRS), etc.

[0013] The CSI-RS resource may include at least one of a non-zero power (NZP) CSI-RS and a CSI-Interference Management (IM). An SS / PBCH block is a block including a synchronization signal (e.g., a primary synchronization signal (PSS) or a secondary synchronization signal (SSS)) and a PBCH (and corresponding DMRS), and may be referred to as an SS block (SSB). An SSB index may be assigned to the time position of the SSB within a half-frame.

[0014] The CSI may include at least one of a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), a CSI-RS Resource Indicator (CRI), a SS / PBCH Block Resource Indicator (SS / PBCH Block Indicator (SSBRI), a Layer Indicator (LI), a Rank Indicator (RI), a Layer 1 (L1)-Reference Signal Received Power (RSRP), a L1-Reference Signal Received Quality (RSRQ), a L1-Signal to Interference plus Noise Ratio (SINR), a L1-Signal to Noise Ratio (SNR), and the like.

[0015] The CSI may have multiple parts. A first part of the CSI (CSI Part 1) may include information with a relatively small number of bits (e.g., RI). A second part of the CSI (CSI Part 2) may include information with a relatively large number of bits (e.g., CQI), such as information determined based on CSI Part 1.

[0016] As CSI feedback methods, (1) periodic CSI (P-CSI) reporting, (2) aperiodic CSI (A(AP)-CSI) reporting, and (3) semi-persistent (semi-persistent, semi-persistent) CSI reporting (Semi-Persistent CSI: SP-CSI) reporting are being considered.

[0017] The UE may be notified of information related to CSI reporting (which may be referred to as CSI reporting configuration information) using higher layer signaling, physical layer signaling (e.g., Downlink Control Information (DCI)), or a combination thereof. The CSI reporting configuration information may be configured, for example, using the RRC information element "CSI-ReportConfig."

[0018] Here, the higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, etc., or a combination thereof.

[0019] The MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (MAC PDU), etc. The broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0020] The CSI reporting configuration information may include, for example, information regarding a reporting period, an offset, etc., which may be expressed in a predetermined time unit (slot unit, subframe unit, symbol unit, etc.). The CSI reporting configuration information may include a configuration ID (CSI-ReportConfigId). The configuration ID may identify parameters such as the type of CSI reporting method (whether it is SP-CSI, etc.), the reporting period, etc. The CSI reporting configuration information may include information (CSI-ResourceConfigId) indicating which signal (or which signal resource) is used to report the measured CSI.

[0021] (Beam Management) Up until now, in Rel. 15 NR, a method of beam management (BM) has been considered. In this beam management, beam selection based on the L1-RSRP reported by the UE has been considered. Changing (switching) the beam of a certain signal / channel may be equivalent to changing the Transmission Configuration Indication state (TCI state) of the signal / channel.

[0022] The beam selected by beam selection may be a transmission beam (Tx beam) or a reception beam (Rx beam). Also, the beam selected by beam selection may be a beam of the UE or a beam of the base station.

[0023] The UE may report (transmit) measurement results for beam management using the PUCCH or PUSCH. The measurement results may be CSI including at least one of L1-RSRP, L1-RSRQ, L1-SINR, L1-SNR, etc. The measurement results may also be called beam measurements, beam measurement results, beam reports, beam measurement reports, etc.

[0024] The CSI measurement for the beam report may include interference measurement. The UE may measure channel quality, interference, etc. using resources for CSI measurement and derive a beam report. The resources for CSI measurement may be, for example, at least one of resources for SS / PBCH blocks, resources for CSI-RS, other reference signal resources, etc. Configuration information for CSI measurement reporting may be configured in the UE using higher layer signaling.

[0025] The beam report may include at least one of channel quality measurement and interference measurement results. The channel quality measurement results may include, for example, L1-RSRP. The interference measurement results may include, for example, L1-SINR, L1-SNR, L1-RSRQ, or other interference-related metrics (e.g., any metrics other than L1-RSRP).

[0026] Note that resources for CSI measurement for beam management may be referred to as beam measurement resources. Furthermore, signals / channels for which the CSI is measured may be referred to as beam measurement signals. Furthermore, CSI measurement / reporting may be interpreted as at least one of measurement / reporting for beam management, beam measurement / reporting, radio link quality measurement / reporting, etc.

[0027] CSI reporting configuration information that takes into account the current NR beam management is included in the RRC information element "CSI-ReportConfig." The information in the RRC information element "CSI-ReportConfig" will be described.

[0028] The CSI reporting configuration information (CSI-ReportConfig) may include report quantity information ("report quantity", which may be represented by the RRC parameter "reportQuantity"), which is information on parameters to be reported. The report quantity information is defined by an ASN.1 object type called "choice type". Therefore, one of the parameters (cri-RSRP, ssb-Index-RSRP, etc.) defined as the report quantity information is set.

[0029] A UE in which an upper layer parameter (e.g., the RRC parameter "groupBasedBeamReporting") included in the CSI reporting configuration information is set to enabled may include in the beam report, for each reporting configuration, multiple beam measurement resource IDs (e.g., SSBRI, CRI) and multiple corresponding measurement results (e.g., L1-RSRP).

[0030] A UE that has one or more numbers of RS resources to be reported configured by higher layer parameters (e.g., RRC parameter "nrofReportedRS") included in the CSI reporting configuration information may include one or more beam measurement resource IDs and one or more corresponding measurement results (e.g., L1-RSRP) for each reporting configuration in the beam report.

[0031] (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).

[0032] 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.

[0033] 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.

[0034] 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).

[0035] 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).

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] The physical layer signaling may be, for example, Downlink Control Information (DCI).

[0041] 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)).

[0042] 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).

[0043] 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.

[0044] 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.

[0045] 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.

[0046] For example, TRS1-1, 1-2, 1-3, and 1-4 are transmitted, and TRS1-1 is notified as a QCL type C / D RS 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.

[0047] (Unified / Common TCI Framework) The unified TCI framework allows UL and DL channels to be controlled by a common framework. Instead of specifying TCI states or spatial relationships for each channel as in Rel. 15, the unified TCI framework may specify a common beam (common TCI state) and apply it to all UL and DL channels, or a common beam for UL may apply to all UL channels and a common beam for DL ​​may apply to all DL channels.

[0048] One common beam for both DL and UL, or one common beam for DL ​​and one common beam for UL (two common beams overall) are considered.

[0049] The UE may assume the same TCI state for UL and DL (joint TCI state, joint TCI pool, joint common TCI pool, joint TCI state set). The UE may assume different TCI states for UL and DL (separate TCI state, separate TCI pool, UL separate TCI pool and DL separate TCI pool, separate common TCI pool, UL common TCI pool and DL common TCI pool).

[0050] The default beams for UL and DL may be aligned via MAC CE based beam management (MAC CE level beam indication). The default TCI state of the PDSCH may be updated to align with the default UL beam (spatial relationship).

[0051] DCI-based beam management (DCI-level beam indication) may indicate a common beam / unified TCI state from the same TCI pool for both UL and DL (joint common TCI pool, joint TCI pool, set). X (>1) TCI states may be activated by the MAC CE. The UL / DL DCI may select one from the X active TCI states. The selected TCI state may apply to both UL and DL channels / RS.

[0052] The TCI pool (set) may be multiple TCI states configured by RRC parameters, or multiple TCI states (active TCI states, active TCI pools, sets) activated by MAC CE among the multiple TCI states configured by RRC parameters. Each TCI state may be a QCL type A / D RS. SSB, CSI-RS, or SRS may be configured as the QCL type A / D RS.

[0053] (Radio Link Monitoring (RLM)) In NR, Radio Link Monitoring (RLM) is used.

[0054] In NR, the network (NW, for example, a 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).

[0055] 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").

[0056] 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.

[0057] 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.

[0058] In the Rel. 16 RLM procedure, the UE follows the implicit RLM-RS determination procedure:

[0059] [Implicit RLM-RS Determination Procedure] If the UE is not provided with an RLM-RS (Radio Link Monitoring RS) and is provided with a TCI state including one or more CSI-RS for PDCCH reception, the UE shall follow steps 1 to 4 below.

[0060] [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.

[0061] 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.

[0062] 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 N = 4, the UE first sorts the search space sets in ascending order of monitoring period, then in descending order of CORESET index. RLM Select RS. Select CORESET.

[0063] 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 maxDepends 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.

[0064] (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.).

[0065] 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.

[0066] 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.

[0067] Note that the beam failure (BF) in this disclosure may also be referred to as a link failure.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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).

[0073] 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.

[0074] 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).

[0075] 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).

[0076] 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.

[0077] 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).

[0078] The base station may determine that the UE has detected a beam failure if there is no notification from the UE or if a predetermined signal (beam recovery request in step S104) is received from the UE.

[0079] In step S103, the UE starts searching for a new candidate beam to be used for new communication in order to recover the beam. The UE may select a new candidate beam corresponding to a predetermined RS by measuring the RS. The RS measured in step S103 may be called a new candidate RS, an RS for identifying a new candidate beam, an NCBI-RS (New Candidate Beam Identification RS), an RS for new beam identification, an RS for new beam identification, an NBI-RS (New Beam Identification RS), a CBI-RS (Candidate Beam Identification RS), a CB-RS (Candidate Beam RS), or the like. The NBI-RS may be the same as or different from the BFD-RS. The new candidate beam may also be simply called a candidate beam or candidate RS.

[0080] The UE may determine a beam corresponding to an RS that satisfies a predetermined condition as a new candidate beam. The UE may determine a new candidate beam, for example, based on an RS among the configured NBI-RSs whose L1-RSRP exceeds a threshold. Note that the criteria for determination are not limited to L1-RSRP. The L1-RSRP related to SSB may be referred to as SS-RSRP. The L1-RSRP related to CSI-RS may be referred to as CSI-RSRP.

[0081] Information about the NBI-RS (e.g., RS resources, number, number of ports, precoding, etc.), information about the new beam identification (NBI) (e.g., the above-mentioned threshold), etc. may be configured (notified) to the UE using higher layer signaling, etc. Information about the new candidate RS (or NBI-RS) may be acquired based on information about the BFD-RS. Information about the NBI-RS may be referred to as information about NBI resources, etc.

[0082] Note that BFD-RS, NBI-RS, etc. may be interchangeably read as Radio Link Monitoring RS (RLM-RS).

[0083] In step S104, the UE that has identified the new candidate beam transmits a beam failure recovery request (BFRQ). The beam recovery request may be referred to as a beam recovery request signal, a beam failure recovery request signal, or the like.

[0084] 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.

[0085] 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.

[0086] In Rel. 15 NR, CB-BFR (Contention-Based BFR), which is a BFR based on a contention-based random access (CBRA) procedure, and CF-BFR (Contention-Free BFR), which is a BFR based on a contention-free random access (CFRA) 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] For CB-BFR, contention resolution may be determined to be successful if the UE receives a PDCCH corresponding to its own C-RNTI.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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).

[0099] [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.

[0100] [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.

[0101] 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 or not to perform BFR may be configured in the UE using higher layer signaling.

[0102] (Transmission power control for PUCCH) In NR, the transmission power of PUCCH is controlled based on the TPC command (also called value, increase / decrease value, correction value, instruction value, etc.) indicated by the value of a specific field (also called TPC command field, first field, etc.) in DCI.

[0103] The TPC command field may be included in a specific DCI (e.g., DCI format 1_0 / 1_1 / 1_2 / 2_2). In Rel. 16 NR, the TPC command field may have a bit length of 2 bits. Also, a specific DCI (e.g., DCI format 2_2) may include a field indicating closed-loop power control (e.g., a closed-loop indicator field).

[0104] For example, the power control adjustment state index l is used to determine the PUCCH transmission power (P ＰＵＣＣＨ、ｂ，ｆ，ｃ (i, q ｕ , q ｄ , l)) may be expressed by the following formula (1):

[0105] The power control adjustment state may also be referred to as a PUCCH power control adjustment state, a first or second state, and so on.

[0106] Furthermore, the PUCCH transmission opportunity i is a predetermined period during which the PUCCH is transmitted, and may be composed of, for example, one or more symbols, one or more slots, or the like.

[0107]

[0108] In formula (1), P ＣＭＡＸ，ｆ，ｃ (i) is, for example, the transmit power of the user terminal (also referred to as maximum transmit power, UE maximum output power, etc.) set for carrier f of serving cell c at transmission opportunity i. Ｏ＿ＰＵＣＣＨ，ｂ，ｆ，ｃ (q ｕ ) is, for example, a parameter related to the target received power (e.g., a parameter related to the transmit power offset, also referred to as a transmit power offset P0 or a target received power parameter) set for the active UL BWP b of the carrier f of the serving cell c at the transmission opportunity i.

[0109] MＰＵＣＣＨ ＲＢ，ｂ，ｆ，ｃ (i) is the number of resource blocks (bandwidth) allocated to PUCCH for transmission opportunity i in active UL BWP b of carrier f with serving cell c and subcarrier spacing μ, for example. ｂ，ｆ，ｃ (q ｄ ) is, for example, the index q of the reference signal (path loss reference RS, DL RS for path loss measurement, PUCCH-PathlossReferenceRS) for downlink BWP associated with the active UL BWP b of carrier f of serving cell c. ｄ is the path loss calculated at the user terminal using

[0110] Δ Ｆ＿ＰＵＣＣＨ (F) is a higher layer parameter given for each PUCCH format. ＴＦ，ｂ，ｆ，ｃ (i) is the transmission power adjustment component (offset) for UL BWP b of carrier f of serving cell c.

[0111] g ｂ，ｆ，ｃ (i, l) is a value based on the TPC command of the power control adjustment state index l of the active UL BWP of the serving cell c and carrier f of the transmission opportunity i (e.g., power control adjustment state, accumulated value of TPC commands, closed-loop value, PUCCH power adjustment state). For example, g ｂ，ｆ，ｃ (i, l) may be expressed by equation (2), where l may be called the closed-loop index.

[0112]

[0113] In equation (2), δPUCCH,b,f,c(m,l) is the TPC command value at PUCCH transmission opportunity m. Ｃ（Ｃ_ｉ）－１ ｍ＝０ δPUCCH,b,f,c(m,l) is the PUCCH transmission opportunity i-i ０ K before ＰＵＣＣＨ (i-i ０ )-1 symbols and K symbols before PUCCH transmission opportunity i ＰＵＣＣＨ (i) The group C (Cｉ ) where i ０ is an integer equal to or greater than 1. The TPC command value for a certain PUCCH transmission opportunity may be the TPC command indicated by the TPC command field value in DCI (e.g., DCI format 1_0 or 1_1) detected in the active UL BWP b of carrier f of serving cell c, or may be the TPC command indicated by the TPC command field value in DCI (e.g., DCI format 2_2) having CRC parity bits scrambled with a specific Radio Network Temporary Identifier (RNTI) (e.g., TPC-PUCCH-RNTI) (CRC-scrambled).

[0114] If the UE is provided with information indicating the use of two PUCCH power control adjustment states (twoPUCCH-PC-AdjustmentStates) and PUCCH spatial relation information (PUCCH-SpatialRelationInfo), l may be set to {0, 1}. If the UE is not provided with information indicating the use of two PUCCH power control adjustment states or PUCCH spatial relation information, l may be set to 0.

[0115] If the UE obtains the TPC command values ​​from DCI format 1_0 or 1_1 and if the UE is provided with PUCCH spatial relation information, the UE may obtain a mapping between the PUCCH spatial relation information ID (pucch-SpatialRelationInfoId) value and the closed-loop index (closedLoopIndex, power adjustment state index l) through an index provided by the P0 ID for PUCCH (p0-PUCCH-Id in p0-Set in PUCCH-PowerControl in PUCCH-Config). When the UE receives an activation command including a value of PUCCH spatial relation information ID, the UE may determine the value of the closed-loop index, which provides the value of l, through a link to the corresponding P0 ID for PUCCH.

[0116] For an active UL BWP b of carrier f of serving cell c, the UE determines P Ｏ＿ＰＵＣＣＨ，ｂ，ｆ，ｃ (q ｕ ) value setting is provided by a higher layer, ｂ，ｆ，ｃ (k, l) = 0, k = 0, 1, ..., i. If the UE is provided with PUCCH spatial relationship information, the UE ｕ , and the PUCCH spatial relationship information associated with q ｕ The value of l may be determined from the value of

[0117] q ｕ may be a P0 ID for PUCCH (p0-PUCCH-Id) indicating P0 for PUCCH (P0-PUCCH) in a P0 set for PUCCH (p0-Set).

[0118] Note that equations (1) and (2) are merely examples and are not limited to these. The user terminal only needs to control the transmission power of the PUCCH based on at least one parameter exemplified in equations (1) and (2), and additional parameters may be included, or some parameters may be omitted. Furthermore, while equations (1) and (2) above control the transmission power of the PUCCH for each active UL BWP of a carrier of a serving cell, this is not limiting. At least some of the serving cell, carrier, BWP, and power control adjustment state may be omitted.

[0119] (Beam Update and PUCCH Power Control Initialization) In Rel. 15 / 16, for the PCell or PSCell, the UE transmits PUCCH on the same cell as the PRACH transmission until 28 symbols after the last symbol of the first PDCCH reception within the search space set provided by the RRC information element "recoverySearchSpaceId" in which the UE detected a DCI format CRC-scrambled by C-RNTI or MCS-C-RNTI, and until the UE receives an activation command for "PUCCH-SpatialRelationInfo" or is provided with "PUCCH-SpatialRelationInfo" for the PUCCH resource.

[0120] In transmitting this PUCCH, the UE uses the same spatial filter as in the last PRACH transmission, and in Equation 1 above, q ｕ = 0, q ｄ =q ｎｅｗ , l=0 and determine the power.

[0121] For the PCell or PSCell, within the search space set provided by the RRC information element "recoverySearchSpaceId" in which the UE detected the C-RNTI or MCS-C-RNTI-based CRC-scrambled DCI format, 28 symbols after the last symbol of the first PDCCH reception, the UE shall use the index q for PDCCH monitoring in the CORESET with index 0. ｎｅｗ Assume the same antenna port quasi-co-location parameters as those associated with

[0122] For the PCell or PSCell, if a BFR MAC CE is sent using message 3 or message A of the CBRA procedure and PUCCH resources are provided using "PUCCH-SpatialRelationInfo", the UE shall transmit PUCCH in the same cell as the PRACH transmission 28 symbols after the last symbol of PDCCH reception that determines the completion of the CBRA procedure.

[0123] In this PUCCH transmission, the UE uses the same spatial filter as in the immediately preceding PRACH transmission, and in Equation 1 above, q ｕ = 0, q ｄ =q ｎｅｗ , l=0, where q ｎｅｗ is the SS / PBCH block index selected for the immediately preceding PRACH transmission.

[0124] The UE may provide configuration for PUCCH transmission with Link Recovery Request (LRR) via "schedulingRequestID-BFR-SCell-r16".

[0125] 28 symbols after the last symbol of reception of a PDCCH with a DCI format that schedules the transmission of a PUSCH with the same HARQ process number as the initial PUSCH transmission and with a toggled new data indicator (NDI) field, the UE shall ｎｅｗ If present, monitor the PDCCHs of all CORESETs in the SCell(s) indicated by the MAC CE using the same antenna port quasi-co-location parameters as associated with it / them.

[0126] Also, 28 symbols after the last symbol of reception of a PDCCH with a DCI format that schedules transmission of a PUSCH with the same HARQ process number as the initial PUSCH transmission and with a toggled NDI field, if "PUCCH-SpatialRelationInfo" is provided for the PUCCH, and the PUCCH with LRR is not transmitted or is transmitted in the PCell or PSCell, and the PUCCH-SCell is included in the SCell indicated by the MAC CE, the UE shall ｕ = 0, q ｄ =q ｎｅｗ , l=0, and q for receiving periodic CSI-RS or SS / PBCH blocks. ｎｅｗThe PUCCH is transmitted in the PUCCH-SCell using the same spatial domain filter as the spatial domain filter corresponding to the PUCCH-SCell.

[0127] Here, the subcarrier spacing (SCS) setting of 28 symbols is the smallest SCS setting among the active DL BWP for PDCCH reception and the SCS settings of the active DL BWP(s) of at least one SCell.

[0128] (Analysis) BFR involves a lot of resource overhead and delay. From the viewpoint of the network, it is preferable for the UE to avoid a beam obstruction state and maintain a beam connection as long as possible.

[0129] One solution to this problem is to frequently trigger beam reporting so that the base station can instruct the UE to select a new beam before the UE encounters a beam failure. However, this method incurs a large resource overhead.

[0130] For example, one or more UEs may perform periodic (P) / semi-persistent (SP) beam reporting (see FIG. 3A). In FIG. 3A, UEs #0 to #2 perform periodic beam reporting. The beam reporting may be transmitted using PUCCH / PUSCH. This beam reporting incurs a lot of resource overhead. For most UEs, such frequent beam reporting is not required.

[0131] Also, for example, one or more UEs may perform aperiodic (A) beam reporting (see FIG. 3B). In FIG. 3B, UE #0 to UE #2 perform aperiodic beam reporting triggered by DCI. Aperiodic beam reporting allows the base station to frequently trigger beam reporting only for necessary UEs. However, triggering frequent beam reporting is difficult considering the capacity / blockage of the PDCCH. Due to PDCCH blockage, the maximum number of DCIs that the base station can transmit per slot is usually limited.

[0132] Therefore, in Rel. 17 and later, the introduction of event-triggered beam reporting is being considered. A UE will perform a beam report when a specific event occurs.

[0133] However, the conditions for the event and the method for reporting a beam based on the event are not clear. If the conditions for the event and the method for reporting a beam based on the event are not clarified, there is a risk that communication throughput will decrease and overhead will increase.

[0134] Therefore, the inventors have conceived a method for reporting beams based on the conditions and events of the event.

[0135] Hereinafter, embodiments of 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.

[0136] In the present disclosure, "A / B / C" and "at least one of A, B, and C" may be read interchangeably.

[0137] In the present disclosure, cell, serving cell, CC, carrier, BWP, DL BWP, UL BWP, active DL BWP, active UL BWP, and band may be interchangeable. In the present disclosure, index, ID, indicator, and resource ID may be interchangeable. In the present disclosure, support, control, controllable, operate, and operable may be interchangeable.

[0138] In the present disclosure, the terms configure, activate, update, indicate, enable, specify, and select may be read interchangeably.

[0139] In the present disclosure, the higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, etc., or a combination thereof. In the present disclosure, RRC, RRC signaling, RRC parameters, higher layer, higher layer parameters, RRC information elements (IEs), and RRC messages may be read interchangeably.

[0140] The MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. The broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0141] In the present disclosure, MAC CE and activation / deactivation command may be read interchangeably.

[0142] In the present disclosure, the terms pool, set, group, list, and candidate may be read interchangeably.

[0143] In the present disclosure, DMRS, DMRS port, and antenna port may be read interchangeably.

[0144] In the present disclosure, the terms special cell, SpCell, PCell, and PSCell may be read interchangeably.

[0145] 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.

[0146] In the present disclosure, CSI-RS, NZP-CSI-RS, periodic (P)-CSI-RS, P-TRS, semi-persistent (SP)-CSI-RS, aperiodic (A)-CSI-RS, TRS, tracking CSI-RS, CSI-RS having TRS information (upper layer parameter trs-Info), NZP CSI-RS resource in an NZP CSI-RS resource set having TRS information, NZP-CSI-RS resource in an NZP-CSI-RS resource set consisting of multiple NZP-CSI-RS resources of the same antenna port, TRS resource, may be interpreted as interchangeable. In the present disclosure, CSI-RS resource, CSI-RS resource set, CSI-RS resource group, information element (IE), may be interpreted as interchangeable.

[0147] 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.

[0148] 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.

[0149] In the present disclosure, CORESET0, CORESET with index 0, and common CORESET may be read interchangeably.

[0150] In the present disclosure, Radio Resource Management (RRM) reports may be interchangeably read as Layer 3 (L3) measurement reports.

[0151] In the present disclosure, DL TCI, DL only TCI, separate DL only TCI, DL common TCI, DL unified TCI, common TCI, and unified TCI may be interchangeable. In the present disclosure, UL TCI, UL only TCI, separate UL only TCI, UL common TCI, UL unified TCI, common TCI, and unified TCI may be interchangeable.

[0152] In the present disclosure, setting / indicating / updating a separate TCI state, setting / indicating / updating a DL-only TCI state, setting / indicating / updating a UL-only TCI state, and setting / indicating / updating a DL and UL TCI state may be read as interchangeable.

[0153] In the present disclosure, in the case of a joint TCI pool, "when a joint TCI pool is configured" and "when a separate TCI pool is configured" may be read interchangeably.

[0154] In the present disclosure, event-based beam reporting, beam reporting based on the occurrence of an event, beam reporting triggered by an event, and event triggered beam reporting may be read interchangeably.

[0155] (Wireless Communication Method) First Embodiment In the first embodiment, the conditions for an event related to a beam report will be described.

[0156] <<Embodiment 1-1>> One or more events may be defined that trigger a beam report for a UE.

[0157] The event may be at least one of the following events: Event (1): The serving beam becomes worse than a certain threshold (e.g., this may be referred to as Event A2). Event (2): The neighbor beam becomes better than the serving beam plus an offset (e.g., this may be referred to as Event A3). Event (3): The neighbor beam becomes better than a certain threshold (e.g., this may be referred to as Event A4). Event (4): The serving beam becomes worse than a first threshold and the neighbor beam becomes better than a second threshold (e.g., this may be referred to as Event A5). Event (5): The neighbor beam becomes better than the serving beam plus an offset (e.g., this may be referred to as Event A6). Event (6): The interference value exceeds a certain threshold (e.g., this may be referred to as Event I1).

[0158] Note that the symbols related to events in this disclosure are merely examples, and the alphabets and numbers described are not limited to these.

[0159] The UE may trigger a beam report based on at least one of the above events, which may be an aperiodic Layer 1 (L1) beam report.

[0160] In this disclosure, a serving beam may refer to a specific beam that is different from the adjacent beams described below (see FIG. 4). In this disclosure, a serving beam may refer to the current TCI state / spatial relationship indicated / activated for a specific channel / signal within the framework of the existing (Rel. 15 / 16) TCI state. Also, a serving beam may refer to the current joint / separate TCI state indicated / activated within the framework of the common / unified TCI state defined in Rel. 17 and later. Also, a serving beam may refer to the beam that is recently reported as an L1 RSRP / SINR beam report.

[0161] In this disclosure, an adjacent beam may refer to a configured / activated TCI state / spatial relationship / joint TCI state / separate TCI state that is different from the serving beam.

[0162] At least one of the events may correspond to an event in an existing (defined in Rel. 15 / 16) RRM report.

[0163] For example, the entering condition for the event (1) may be that the sum of the measurement result of the serving beam and a specific hysteresis parameter falls below a specific threshold, and the leaving condition for the event (1) may be that the difference between the measurement result of the serving beam and the specific hysteresis parameter exceeds a specific threshold.

[0164] For example, the input condition for the event (2) may be that the sum of the measurement result of the adjacent beam, the offset specific to the measurement object of the adjacent beam, and the offset specific to the adjacent beam minus a specific hysteresis parameter exceeds the sum of the measurement result of the specific beam, the offset specific to the measurement object of the specific beam, the offset specific to the specific beam, and the offset related to the event.Furthermore, the exit condition for the event (2) may be that the sum of the measurement result of the adjacent beam, the offset specific to the measurement object of the adjacent beam, the offset specific to the adjacent beam, and the specific hysteresis parameter falls below the sum of the measurement result of the specific beam, the offset specific to the measurement object of the specific beam, the offset specific to the specific beam, and the offset related to the event.

[0165] For example, the input condition for the event (3) may be that the sum of the measurement result of the adjacent beam, the offset specific to the measurement object of the adjacent beam, and the offset specific to the adjacent beam minus a specific hysteresis parameter exceeds a specific threshold.Furthermore, the exit condition for the event (3) may be that the sum of the measurement result of the adjacent beam, the offset specific to the measurement object of the adjacent beam, the offset specific to the adjacent beam, and the specific hysteresis parameter falls below a specific threshold.

[0166] For example, the above event (4) may have a first input condition that the sum of the measurement result of the serving beam and a specific hysteresis parameter is below a first threshold, and a second input condition that the sum of the measurement result of the adjacent beam, the offset specific to the measurement object of the adjacent beam, and the offset specific to the adjacent beam minus the specific hysteresis parameter is above a second threshold.

[0167] Furthermore, the above event (4) may have a first departure condition that the difference between the measurement result of the serving beam and a specific hysteresis parameter exceeds a first threshold, and a second departure condition that the sum of the measurement result of the adjacent beam, the offset specific to the measurement object of the adjacent beam, the offset specific to the adjacent beam, and the specific hysteresis parameter falls below a second threshold.

[0168] For example, the input condition for the event (5) may be that the sum of the measurement results of the adjacent beam and the inherent offset of the adjacent beam minus a specific hysteresis parameter exceeds the sum of the measurement results of the serving beam, the inherent offset of the serving beam, and the offset related to the event.Furthermore, the exit condition for the event (5) may be that the sum of the measurement results of the adjacent beam, the inherent offset of the adjacent beam, and the specific hysteresis parameter falls below the sum of the measurement results of the serving beam, the inherent offset of the serving beam, and the offset related to the event.

[0169] For example, the input condition for the event (6) may be that the value of interference with the serving beam exceeds a specific threshold, and the release condition for the event (6) may be that the value of interference with the serving beam falls below a specific threshold.

[0170] In the present disclosure, at least one of the threshold (specific / first / second threshold), measurement result, offset, and hysteresis parameter may be calculated (or expressed) in specific units (e.g., dB, dBm).

[0171] In the present disclosure, at least one of the threshold (specific / first / second threshold), offset, and hysteresis parameter may be configured in the UE using higher layer signaling, or the offset may be specified in advance.

[0172] As already mentioned, the "measurement result" in the first embodiment may be, for example, at least one of L1-RSRP, L1-RSRQ, L1-SINR, L1-SNR, etc., or may be a corresponding L3 measurement result (for example, L3-RSRP). Hereinafter, "L1-", "L3-", etc. may be omitted.

[0173] <<Embodiment 1-2>> One or more serving beams may be configured / instructed to a UE.

[0174] One serving beam may be configured / instructed to the UE (embodiment 1-2-1).

[0175] The one serving beam may be a beam (TCI state) corresponding to a particular CORESET, for example, the CORESET with the smallest (or largest) CORESET ID.

[0176] Also, when a UE is configured to use a common TCI state, the one serving beam may be one indicated / activated joint TCI state / separate TCI state for DL.

[0177] The UE may determine the occurrence of at least one of the above events by comparing the received power / reception quality of the one serving beam with the received power / reception quality of other beams (adjacent beams).

[0178] 5A is a diagram showing an example of beam comparison according to embodiment 1-2. As shown in the example of FIG. 5A, one serving beam and other adjacent beams are configured for a UE. The UE compares the one serving beam with the other adjacent beams to determine the occurrence of an event. In the example of FIG. 5A, RSRP is used as the received power of the beam.

[0179] A specific offset may be used to compare the serving beam with the adjacent beam. For example, a specific offset may be added to the measurement result of the serving beam and the measurement result of the adjacent beam may be compared. Using an offset in this way can prevent excessive beam switching.

[0180] The specific offset may be configured / notified to the UE using higher layer signaling, or may be specified in advance in a specification.

[0181] Multiple serving beams may be configured / instructed to the UE (embodiment 1-2-2).

[0182] The multiple serving beams may be beams (TCI states) corresponding to a specific CORESET. The specific CORESET may be, for example, a CORESET corresponding to a specific number of CORESET IDs or all CORESETs configured for the UE. The multiple serving beams may also be active TCI states for multiple or all PDSCHs.

[0183] Also, when a UE is configured to use a common TCI state, the multiple serving beams may be in a joint TCI state / DL separate TCI state that is configured / notified using higher layer signaling (e.g., RRC signaling / MAC CE).

[0184] The UE may determine the occurrence of at least one of the above events by comparing the received power / reception quality of at least one of the multiple serving beams with the received power / reception quality of other beams (adjacent beams).

[0185] For example, the beam with the lowest (or highest) reception power / reception quality among the plurality of serving beams may be compared with the adjacent beam. Alternatively, for example, the average value of the reception power / reception quality of the plurality of serving beams may be calculated, and the calculated value may be compared with the reception power / reception quality of the adjacent beam.

[0186] 5B is a diagram showing another example of beam comparison according to embodiment 1-2. As shown in the example of FIG. 5B, three serving beams and other adjacent beams are configured for a UE. The UE compares the three serving beams with the other adjacent beams to determine the occurrence of an event. In the example of FIG. 5B, RSRP is used as the received power of the beams.

[0187] A specific offset may be used to compare the serving beam with the adjacent beam. For example, a specific offset may be added to the measurement result of the serving beam and the measurement result of the adjacent beam may be compared. By using an offset in this way, excessive beam switching can be prevented.

[0188] The specific offset may be configured / notified to the UE using higher layer signaling, or may be specified in advance in a specification.

[0189] The UE may also determine one or more serving beams (embodiments 1-2-3).

[0190] For example, the UE may determine the top X beams (X is an integer greater than or equal to 1) in terms of received power / received quality from among the multiple measured beams as the serving beam.

[0191] The X may be set by higher layer signaling, may be predefined in a specification, or may be determined based on a report of UE capability information.

[0192] According to the above embodiments 1-1 / 1-2, the network can suppress an increase in the frequency of beam reports by the UE.

[0193] Since UEs make beam reports when events of specific conditions occur, only necessary UEs can make frequent beam reports, thereby suppressing increases in resource overhead.

[0194] <<Embodiments 1-3>> A base station may configure periodic / semi-persistent / aperiodic beam reports (first beam reports) for multiple UEs. In addition, the base station may configure periodic / semi-persistent beam reports (second beam reports) with a shorter period (or higher frequency) than the first beam reports for UEs in which an event occurs at a frequency equal to or greater than a specific threshold.

[0195] In the present disclosure, the first beam report may be a non-event-based beam report, and the second beam report may be the event-triggered beam report described above in the first embodiment.

[0196] An event occurring at a frequency equal to or greater than a certain threshold may mean that the event occurs a certain number of times or more in a certain number (an integer equal to or greater than 1) of time units (e.g., slots / symbols).

[0197] Information regarding at least one of a reporting period, a period, and a number of times for the beam report may be configured / notified / instructed to the UE using higher layer signaling / physical layer signaling. Information regarding the first beam report and information regarding the second beam report may be configured / notified / instructed separately.

[0198] This allows the base station to determine which terminals require frequent beam reports based on the frequency of event occurrence.

[0199] 6 is a diagram showing an example of a beam report according to embodiments 1 to 3. In FIG. 6, a first beam report and a second beam report are configured for UE #0 to UE #2. As shown in FIG. 6, for UE #0 where a second beam report event occurs frequently (a frequency equal to or greater than a certain threshold), the base station may configure a first beam report / second beam report with a shorter period.

[0200] Furthermore, the base station may change (e.g., set a longer) the period of the second beam report based on the frequency of occurrence of events related to the second beam report. For example, if events related to the second beam report occur infrequently in the UE (a frequency equal to or less than a certain threshold), the base station may set a longer period of the second beam report to the UE. This makes it possible to reduce the load of checking the occurrence of events by the UE.

[0201] The UE may transmit information / request to the NW to change the period of the first beam report / second beam report based on the frequency of occurrence of the event. The information / request may be transmitted using RRC signaling / MAC CE / UCI.

[0202] According to the first embodiment described above, events for which beam reporting is performed can be appropriately defined.

[0203] Second Embodiment In a second embodiment, the operation of a UE / base station after an event occurs will be described.

[0204] <<Embodiment 2-1>> The UE may transmit a PRACH when a specific event occurs (when the input condition of the specific event as described in embodiment 1-1 is satisfied). In other words, in embodiment 2-1, the event-triggered beam report may correspond to the PRACH.

[0205] The PRACH opportunity / resource of the transmitted PRACH may be associated with information about the beam to which the PRACH is changed (new beam). The UE may transmit information about the new beam to the NW using the PRACH.

[0206] A plurality of PRACH opportunities / resources may be configured for the UE, and the UE may select a PRACH opportunity / resource from the plurality of PRACH opportunities / resources and transmit / report information about the new beam.

[0207] PRACH opportunities / resources for beam reporting and PRACH opportunities / resources for other uses (e.g., BFR) may be configured separately. This is preferably available in CFRA. According to this, the NW can determine that it has received an event-based beam report based on the PRACH opportunities / resources.

[0208] In addition, the PRACH opportunities / resources for beam reporting and those for other uses (e.g., BFR) may be common, which is advantageously usable in CBRA.

[0209] According to this, the NW cannot determine that an event-based beam report has been received based on the PRACH opportunity / resource. Therefore, the UE may transmit Message 3 / Message A including specific information. The NW may determine that an event-based beam report has been received based on the specific information.

[0210] The specific information may be included in a MAC CE. The MAC CE may be called an event-triggered beam reporting MAC CE. The MAC CE may be the MAC CE described in the following embodiment 2-2, or may be another MAC CE (e.g., a MAC CE defined in Rel. 17 or later).

[0211] In embodiment 2-2, an event-triggered beam report may correspond to a MAC CE. A MAC CE including specific information for notifying an event-based beam report (hereinafter, may be referred to as a MAC CE for an event-triggered beam report, a first MAC CE, etc.) may be an existing MAC CE (defined in Rel. 15 / 16).

[0212] In embodiment 2-2, the first MAC CE may have the same configuration as the MAC CE for BFR. The MAC CE for BFR may include at least one of a BFR MAC CE and a Truncated BFR MAC CE.

[0213] The first MAC CE may include multiple fields, including a field indicating beam failure detection for the SpCell (SP field, denoted as "SP"), a field indicating beam failure detection for the SCell with serving cell index (ID) i (C ｉ Field, "C ｉ "), a field indicating the presence of a candidate RS ID field in the same octet (AC field, denoted as "AC"), a candidate RS ID field, a reserved bit field (R field, denoted as "R"), and a field indicating a value of received power / received quality (e.g., RSRP).

[0214] The UE may use a specific field (e.g., at least one of the R field and the SP field) to indicate whether the first MAC CE is a MAC CE for BFR or a MAC CE for an event-triggered beam report.

[0215] The UE may be configured using higher layer signaling (e.g., RRC signaling) to notify whether the first MAC CE is a MAC CE for BFR or a MAC CE for an event-triggered beam report.

[0216] The UE may indicate that the first MAC CE is a MAC CE for BFR by setting the value of a specific (e.g., first) specific field included in the first MAC CE to a first value (e.g., 0 (or 1)).

[0217] The UE may also indicate that the first MAC CE is a MAC CE for event-triggered beam reporting by setting the value of a specific (e.g., first) specific field included in the first MAC CE to a second value (e.g., 1 (or 0)).

[0218] The UE may use multiple MAC CEs when reporting multiple candidate RS IDs for one cell and / or when reporting multiple received power / received quality (e.g., RSRP) values ​​for one cell.

[0219] The UE may receive an UL grant (DCI) for the first MAC CE. If the UE does not receive an UL grant for the first MAC CE, the UE may transmit an SR to the NW to request an UL grant. If the UE is not configured with resources for SR, the UE may transmit a PRACH as specified in Rel. 15 / 16.

[0220] The first MAC CE may contain information for multiple cells. ｉ The octet containing the field may be set.

[0221] Also, the first MAC CE may include only information of one cell (for example, the own cell transmitting the MAC CE). In this case, C ｉ The octet containing the field may not be set (may be omitted).

[0222] At least one candidate RS ID field may be present in the MAC CE for event-triggered beam reporting, in which case the initial AC field may be changed to an R bit or the value of the AC field may be ignored.

[0223] The candidate RS ID field may not be present in the MAC CE for BFR.

[0224] 7 is a diagram illustrating an example of the configuration of a MAC CE according to embodiment 2-2. In FIG. 7, the UE uses the MAC CE to transmit an event-triggered beam report to the NW.

[0225] The MAC CE shown in FIG. 7 has the same configuration as the MAC CE for BFR. Specifically, the MAC CE includes an SP field, a C ｉ The fields include a candidate RS ID field, an AC field, and an R field (where i is an integer from 1 to 7).

[0226] In Fig. 7, the UE may use the SP field included in the MAC CE to indicate that the MAC CE is a MAC CE for an event-triggered beam report. Also, the UE may use the first R field included in the MAC CE to indicate that the MAC CE is a MAC CE for an event-triggered beam report.

[0227] A field may be added to the MAC CE for event-triggered beam reporting to report multiple candidate RS IDs (and corresponding received power / received quality (e.g., RSRP) values).

[0228] The number (maximum number) of candidate RS IDs to be reported by the UE may be configured using higher layer signaling, or the UE may determine candidate RS IDs whose number is less than the configured maximum number.

[0229] 8 is a diagram illustrating another example of the configuration of a MAC CE according to embodiment 2-2. As illustrated in FIG. 8, fields (first to fourth candidate RS ID fields) for reporting four candidate RS IDs (and corresponding received power / received quality (e.g., RSRP) values) are added to the first MAC CE. The UE may report up to four candidate RS IDs (and RSRP values) whose received power / received quality exceeds (is equal to or exceeds) a specific threshold.

[0230] The R field shown in Figure 8 may indicate whether the next octet exists or not, which can reduce the signaling overhead of the MAC CE.

[0231] A MAC CE containing the fields shown in Figure 8 may contain information for multiple cells. ｉ The octet containing the field may be set.

[0232] Also, the MAC CE including the fields shown in FIG. 8 may include only information of one cell (for example, the own cell transmitting the MAC CE). In this case, C ｉ The octet containing the field may not be set (may be omitted).

[0233] At least one candidate RS ID field may be present in a MAC CE containing the fields shown in Figure 8. In this case, the initial AC field may be changed to an R bit, or the value of the AC field may be ignored.

[0234] In addition, the event-triggered beam report may be a CSI report.

[0235] According to the second embodiment described above, for beam reporting based on the occurrence of an event, the operation of the UE / base station after the event occurs can be appropriately controlled.

[0236] Third Embodiment In a third embodiment, updating / changing of a beam state in a beam report based on the occurrence of an event will be described.

[0237] Hereinafter, the first timing may be at least one of after the CFRA / CBRA procedure is completed and after the first MAC CE transmission is completed.

[0238] In the following, the second timing may be defined as at least one of receiving a signal equivalent to a BFR response, receiving DCI in a dedicated search space, receiving message 4 (or a signal equivalent to message 4), and receiving DCI equivalent to an ACK (acknowledgment) to a PUSH in a random access procedure.

[0239] After the first timing is met and a certain period of time has elapsed, the UE / base station may update the state of the beam (which may also be called the beam state / beam assumption).

[0240] Furthermore, after the first timing is met and a specific period of time has elapsed, the UE / base station may reset / update parameters / states related to the transmission power control of UL channels / signals (e.g., PUSCH / PUCCH / SRS).

[0241] Also, after the first timing and the second timing are met and a specific period of time has elapsed, the UE / base station may update the beam status.

[0242] Furthermore, after the first timing and the second timing are satisfied and a specific period of time has elapsed, the UE / base station may reset / update parameters / states related to the transmission power control of UL channels / signals (e.g., PUSCH / PUCCH / SRS).

[0243] The beam state update may be performed for a beam of a specific channel / signal (e.g., PDCCH / PUCCH). The beam state update may also be performed for beams of multiple channels / signals (e.g., all channels / signals). The beam state update may also be performed for beams of multiple channels / signals (e.g., all channels / signals excluding CSI-RS / SRS).

[0244] After the first timing is satisfied and a specific period has elapsed, the base station may not update the state of the beam. Also, after the first timing and the second timing are satisfied and a specific period has elapsed, the base station may not update the state of the beam.

[0245] For example, the beam status update at the base station may be performed when an (explicit) response to the event-triggered beam report is made. The UE may assume that the beam status update will be performed when it receives an (explicit) response to the event-triggered beam report. The occurrence of the second timing may indicate that the base station has completed reception of the event-triggered beam report. The "response" in the third embodiment may correspond to at least one of the signals / information received at the second timing.

[0246] Completion of reception of an event-triggered beam report by the base station may mean permission / approval of a change to the beam reported using the event-triggered beam report.

[0247] Two states may be defined: a state (first state) in which, after the base station has completed receiving an event-triggered beam report, permission / approval is not given to change to the beam reported using the event-triggered beam report; and a state (second state) in which, after the base station has completed receiving an event-triggered beam report, permission / approval is given to change to the beam reported using the event-triggered beam report.

[0248] The UE may receive responses (channels / signals carrying responses) corresponding to each of the two states, and based on the received responses, the UE may determine whether to update / change the beam state of a particular channel / signal after the response.

[0249] For example, if a response indicating a first state is received, the UE may decide not to update / change the beam state of a particular channel / signal (e.g., all channels / signals) after receiving the response.

[0250] Also, for example, if a response indicating a second state is received, the UE may decide to update / change the beam state of a particular channel / signal (e.g., all channels / signals) after receiving the response.

[0251] The UE may receive responses corresponding to the two states using different CORESETs / search spaces, or may receive responses corresponding to the two states using the same (or a common) CORESET / search space but different DCIs, where the different DCIs may mean at least one of DCIs including at least one different field, DCIs with different DCI formats, and DCIs that are CRC-scrambled using different RNTIs.

[0252] Note that this embodiment may be applied only to the case where the UE notifies / instructs that the MAC CE to be transmitted is a MAC CE for event-triggered beam reporting by using message 3 / message A. This allows the NW to determine for what purpose the CBRA procedure is used.

[0253] According to the third embodiment described above, it is possible to appropriately control the updating / changing of the beam state in a beam report based on the occurrence of an event.

[0254] <Fourth embodiment> In the fourth embodiment, the operation of existing (defined up to Rel. 15 / 16) beam reports (which may also be called first beam reports) and beam reports based on the occurrence of an event (which may also be called second beam reports) is described.

[0255] The UE may control the implementation of the first beam report and the second beam report based on at least one of embodiments 4-1 to 4-5 described below.

[0256] 9A and 9B are diagrams illustrating an example of a timeline of event occurrence according to the fourth embodiment. In FIGS. 9A and 9B, a first beam report is set to be performed. In FIG. 9A, the first beam report is not performed within a specific period from the occurrence of the event. On the other hand, in FIG. 9B, the first beam report is performed within a specific period from the occurrence of the event.

[0257] 10A and 10B are diagrams illustrating another example of a timeline of event occurrence according to the fourth embodiment. In FIGS. 10A and 10B, a first beam report is set to be performed. In FIG. 10A, no event occurs within a specific period before the first beam report. On the other hand, in FIG. 10B, an event occurs within a specific period before the first beam report.

[0258] The following embodiments 4-1 to 4-5 describe the case where the first beam report is made within a specific period from the occurrence of an event, as shown in Figure 9B, but may also be applied appropriately to the case where an event occurs within a specific period before the first beam report, as shown in Figure 10B.

[0259] When configured / instructed to make a first beam report at a specific period after the occurrence of an event, the UE may make the first beam report without making a second beam report (embodiment 4-1).

[0260] When configured / instructed to make a first beam report within a specific period of time from the occurrence of an event, the UE may not make the first beam report but may make a second beam report (embodiment 4-2).

[0261] When configured / instructed to make a first beam report within a specific period of time from the occurrence of an event, the UE may make both a first beam report and a second beam report (embodiment 4-3).

[0262] When configured / instructed to make a first beam report within a specific period from the occurrence of an event, the UE may make at least one of a first beam report and a second beam report based on specific conditions (embodiment 4-4).

[0263] In embodiment 4-4, the specific condition may be a condition based on information reported using the second beam report. For example, if a new candidate beam reported using the second beam report is included in (or is the same as) the first beam report, the UE may perform the first beam report but not the second beam report. Otherwise, the UE may perform the second beam report or may perform both the first beam report and the second beam report.

[0264] When configured / instructed to make a first beam report within a specific period of time from the occurrence of an event, the UE may make at least one of a first beam report and a second beam report based on the configuration of upper layer signaling (embodiments 4-5).

[0265] In embodiments 4 and 5, for example, when configured using higher layer signaling, the UE may perform the second beam report or may perform both the first beam report and the second beam report. Otherwise, the UE may perform the first beam report but not the second beam report.

[0266] According to embodiments 4-5, by using MAC CE to send the second beam report, more information can be included and transmitted to the network.

[0267] The specific period in this embodiment may be predefined in the specifications, or may be set / notified to the UE using higher layer signaling.

[0268] According to the above fourth embodiment, it is possible to appropriately control the implementation of existing beam reporting (defined up to Rel. 15 / 16) and the implementation of beam reporting based on the occurrence of an event.

[0269] Fifth Embodiment An upper layer parameter (RRC IE) / UE capability corresponding to a function (feature) in at least one of the above embodiments may be defined. The UE capability may indicate that the function is supported.

[0270] A UE configured with higher layer parameters corresponding to the function (enabling the function) may perform the function. It may also be specified that "a UE not configured with higher layer parameters corresponding to the function shall not perform the function (for example, in accordance with Rel. 15 / 16)."

[0271] A UE that reports a UE capability indicating that it supports the function may perform the function. It may also be specified that a UE that does not report a UE capability indicating that it supports the function shall not perform the function (e.g., in accordance with Rel. 15 / 16).

[0272] If the UE reports a UE capability indicating that it supports the function and the corresponding higher layer parameters are configured, the UE may perform the function. It may also be specified that "if the UE does not report a UE capability indicating that it supports the function or if the corresponding higher layer parameters are not configured, the UE shall not perform the function (e.g., in accordance with Rel. 15 / 16)."

[0273] The UE capability may indicate whether the UE supports this feature.

[0274] UE capability may be defined as whether or not it supports event-triggered beam reporting.

[0275] UE capability may be defined as whether or not it supports PRACH based on event-triggered beam reporting.

[0276] UE capability may be defined as whether or not it supports MAC CE based on event-triggered beam reporting (MAC CE transmitted by PUSCH).

[0277] UE capability may be defined by whether it supports a new MAC CE (MAC CE transmitted by PUSCH) based on event-triggered beam reporting (defined in Rel. 17 and later). If the UE does not support this UE capability and supports BFR for SCell and / or BFR with CBRA using BFR MAC CE in Rel. 16, the BFR MAC CE may be used for event-triggered beam reporting.

[0278] UE capability may be defined as the number of new candidate beam (RS) IDs that the UE can report per CC / MAC CE.

[0279] UE capability may be defined as whether it supports reporting of received power / received quality (e.g., RSRP) values ​​within the MAC CE.

[0280] According to the fifth embodiment, the UE can achieve the above functions while maintaining compatibility with existing specifications.

[0281] (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.

[0282] 11 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).

[0283] 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.

[0284] 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.

[0285] 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))).

[0286] 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.

[0287] 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).

[0288] 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.

[0289] 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.

[0290] 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.

[0291] 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.

[0292] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0293] 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).

[0294] 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.

[0295] 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.

[0296] 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.

[0297] 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).

[0298] 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.

[0299] 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.

[0300] 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.

[0301] 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.

[0302] 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.

[0303] 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.

[0304] 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.

[0305] 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.

[0306] 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).

[0307] (Base Station) Fig. 12 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.

[0308] 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.

[0309] 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.

[0310] 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.

[0311] 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.

[0312] 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.

[0313] 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.

[0314] 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.

[0315] 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.

[0316] 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.

[0317] 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.

[0318] 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.

[0319] On the other hand, the transceiver unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 130.

[0320] 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.

[0321] 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.

[0322] 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.

[0323] The transmitting section and receiving section of the base station 10 in the present disclosure may be configured by at least one of the transmitting / receiving section 120, the transmitting / receiving antenna 130, and the transmission path interface 140.

[0324] The control unit 110 may control the reception of at least one of a first beam report not based on an event and a second beam report based on the event based on an event related to at least one of the multiple beams in the terminal. When the second beam report is performed, the transceiver unit 120 may receive at least one of a random access channel related to first information related to a new candidate beam and a Medium Access Control (MAC) control element including second information related to the new candidate beam (first and second embodiments).

[0325] (User Terminal) Fig. 13 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal 20 may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0326] 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.

[0327] 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.

[0328] 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.

[0329] 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.

[0330] 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.

[0331] 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.

[0332] 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.

[0333] 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.

[0334] 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.

[0335] 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.

[0336] 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.

[0337] 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.

[0338] 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.

[0339] 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.

[0340] 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.

[0341] 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, the transmitting / receiving antenna 230, and the transmission path interface 240.

[0342] The control unit 210 may control at least one of a first beam report not based on an event and a second beam report based on the event based on an event related to at least one of the plurality of beams. When performing the second beam report, the transmission unit 220 may transmit at least one of a random access channel related to first information related to a new candidate beam and a Medium Access Control (MAC) control element including second information related to the new candidate beam (first and second embodiments).

[0343] The MAC control element may have a common configuration with the MAC control element for beam obstruction detection (second embodiment).

[0344] After transmitting the MAC control element and after a specific period of time has elapsed, the control unit 210 may control at least one of updating the beam state of at least one of a specific channel and signal and resetting the transmission power control parameters of at least one of the uplink channel and uplink signal (third embodiment).

[0345] The control unit 210 may control the sending of at least one of the first beam report and the second beam report based on the timing of the event occurrence and the timing of the first first beam report after the occurrence timing (fourth embodiment).

[0346] (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.

[0347] 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.

[0348] 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. 14 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.

[0349] 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.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] 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.

[0354] 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.

[0355] 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.

[0356] 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.

[0357] 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).

[0358] 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.

[0359] 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.

[0360] (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.

[0361] 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.

[0362] 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.

[0363] 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.

[0364] 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.

[0365] 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.

[0366] 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.

[0367] 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.

[0368] 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.

[0369] 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.

[0370] 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.

[0371] 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.

[0372] 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.

[0373] 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.

[0374] 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.

[0375] 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.

[0376] 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.

[0377] 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.

[0378] 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."

[0379] 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.

[0380] 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.

[0381] 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.

[0382] 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.

[0383] 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.

[0384] 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.

[0385] 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.

[0386] 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).

[0387] 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).

[0388] 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).

[0389] 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.

[0390] 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.

[0391] 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).

[0392] 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.

[0393] 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.

[0394] 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.

[0395] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0396] 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.

[0397] At least one of the base station and the mobile station may be referred to as a transmitting device, a receiving device, a wireless communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). 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.

[0398] 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.

[0399] 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.

[0400] 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.

[0401] 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.

[0402] 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) (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 The present invention may be applied to systems that use IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other appropriate wireless communication methods, or to next-generation systems that are based on these and are extended thereto. In addition, the present invention may be applied to a combination of multiple systems (for example, a combination of LTE or LTE-A and 5G).

[0403] 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."

[0404] 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.

[0405] 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.

[0406] 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.

[0407] 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.

[0408] Furthermore, "judgment (decision)" may be read as "assuming," "expecting," "considering," or the like.

[0409] The "maximum transmit power" in this disclosure may mean the maximum value of transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

[0410] 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."

[0411] 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.

[0412] 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."

[0413] 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.

[0414] 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.

[0415] 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

A receiving unit that receives upper layer parameters corresponding to events related to reference signal received power (RSRP) for each of a plurality of transmission configuration indication (TCI) states for both the uplink and the downlink; A terminal having a control unit that controls a channel state information (CSI) report triggered by any one of the plurality of events. The plurality of TCI states in claim 1 are TCI states indicated for both the uplink and the downlink, The terminal according to claim 1, wherein the CSI report is performed when a condition regarding a threshold of RSRP corresponding to the indicated TCI state is satisfied. The plurality of TCI states in claim 1 are TCI states activated for both the uplink and the downlink, The terminal according to claim 1, wherein the CSI report is performed when a condition regarding a threshold of RSRP corresponding to the activated TCI state is satisfied. A step of receiving upper layer parameters corresponding to events related to reference signal received power (RSRP) for each of a plurality of transmission configuration indication (TCI) states for both the uplink and the downlink; A wireless communication method for a terminal having a step of controlling a channel state information (CSI) report triggered by any one of the plurality of events. A transmitting unit that transmits upper layer parameters corresponding to events related to reference signal received power (RSRP) for each of a plurality of transmission configuration indication (TCI) states for both the uplink and the downlink; A base station having a receiving unit that receives a channel state information (CSI) report triggered by any one of the plurality of events. A system including a terminal and a base station, The terminal is A receiving unit that receives upper layer parameters corresponding to events related to reference signal received power (RSRP) for each of a plurality of transmission configuration indication (TCI) states for both the uplink and the downlink; A control unit that controls a channel state information (CSI) report triggered by any one of the plurality of events, The base station is A system having a transmitting unit that transmits the upper layer parameters.