Terminal, wireless communication method and system

Abstract

The present invention performs UL transmission after BFR in a suitable manner. A terminal according to one aspect of the present disclosure has: a reception unit that receives a response to a report of a candidate beam in a secondary cell beam failure recovery (BFR) procedure; and a control unit for, after a given period from a final symbol in reception of the response, assuming that a sounding reference signal (SRS) resource is transmitted in a specific cell using a spatial domain filter concerning the reported candidate beam.

Description

[Technical field]

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

[0002] In the Universal Mobile Telecommunications System (UMTS) network, Long Term Evolution (LTE) has been specified for the purpose of achieving higher data rates and lower latency (Non-Patent Document 1). In addition, LTE-Advanced (3GPP Rel. 10-14) has been specified for the purpose of achieving higher capacity and greater sophistication of 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. [Prior art documents] [Non-patent literature]

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

[0005] In NR, it is being considered that a user terminal (User Equipment (UE)) will implement a procedure (which may be called a Beam Failure Recovery (BFR) procedure, or BFR, etc.) to detect a beam failure (BF) and switch to another beam.

[0006] Rel.15 BFR specifies that after the RA procedure for BFR is completed (may be called post-BFR, post-BFR completion, etc.), before an explicit beam is configured / activated, the QCL assumptions for a particular PDCCH and the spatial relationship for a particular PUCCH are updated based on the new candidate beam. This prevents a situation in which a failed beam continues to be used and proper communication cannot be performed.

[0007] However, for BFR for secondary cells, which is being considered in Rel.16 NR, the spatial relationship (beam) update for UL channels / signals after BFR has not yet been considered. If the spatial relationship is not applied properly, there is a risk that the throughput, communication quality, etc. will be degraded.

[0008] Therefore, the present disclosure relates to a terminal and a wireless communication method capable of performing UL transmission favorably after BFR. allusion to law One of the objectives of the present invention is to provide a system for [Means for solving the problem]

[0009] A terminal according to an embodiment of the present disclosure is a terminal that, in a beam failure recovery (BFR) procedure of a secondary cell, responds to a report of an index related to a channel state measurement reference signal (CSI-RS) or a synchronization signal block (SSB) using a medium access control element (MAC CE). The DCI format as the answer A receiving unit that receives Schedule a PUSCH transmission having the same HARQ process number as that used for transmitting a first Physical Uplink Shared Channel (PUSCH) carrying the MAC CE, and schedule a Physical Downlink Control Channel (PDCCH) of the DCI format having a New Data Indicator (NDI) field value that is toggled. From the last symbol received 28 symbols Thereafter, a spatial domain filter is used that is the same as the spatial domain filter that corresponds to the index, and the spatial domain filter is calculated based on the index. Measured Transmission power of the Sounding Reference Signal (SRS) The transmission power of the SRS is determined using the formula and a control unit that uses the SRS resource set to control transmission of an SRS for a SRS resource set whose purpose is beam management or antenna switching. Effect of the Invention

[0010] According to one embodiment of the present disclosure, UL transmission can be preferably performed after BFR. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an example of a beam recovery procedure in Rel. 15 NR. [Diagram 2] FIG. 2 is a diagram showing an example of a beam recovery procedure in Rel.16 NR. [Diagram 3] FIG. 3 is a diagram illustrating an example of a spatial relationship update after a SCell BFR according to an embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. [Diagram 5] FIG. 5 is a diagram illustrating an example of the configuration of a base station according to an embodiment. [Figure 6] FIG. 6 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. [Figure 7] FIG. 7 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (Beam Damage Recovery) In NR, communication using beamforming is being considered. For example, a UE and a base station (e.g., gNodeB (gNB)) may use a beam used for transmitting a signal (also called a transmitting beam, Tx beam, etc.) and a beam used for receiving a signal (also called a receiving beam, Rx beam, etc.).

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

[0014] In NR, in order to suppress the occurrence of RLF, when the quality of a specific beam deteriorates, a procedure for switching to another beam (which may be called Beam Recovery (BR), Beam Failure Recovery (BFR), L1 / L2 (Layer 1 / Layer 2) beam recovery, etc.) is being considered. The BFR procedure may be simply called BFR.

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

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

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

[0018] The RS may be at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), a Mobility Reference Signal (MRS), a signal included in an SSB, an SSB, a CSI-RS, a Demodulation Reference Signal (DMRS), a beam-specific signal, etc., or a signal configured by extending or modifying these. The RS measured in step S101 may be called an RS for beam failure detection (Beam Failure Detection RS: BFD-RS), etc.

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

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

[0021] The criteria for the judgment are not limited to BLER, and may be Layer 1 Reference Signal Received Power (L1-RSRP) in the physical layer. Also, instead of or in addition to RS measurement, beam failure detection may be performed based on a downlink control channel (Physical Downlink Control Channel (PDCCH)). The BFD-RS may be expected to be quasi-co-located (QCL) with the DMRS of the PDCCH monitored by the UE.

[0022] Here, the QCL is an index indicating the statistical properties of a channel. For example, when a signal / channel and another signal / channel are in a QCL relationship, it may mean that it can be assumed that at least one of the following is the same (QCL with respect to at least one of these): Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (e.g., spatial Rx Filter / Parameter, spatial Tx (transmission) Filter / Parameter) between these different signals / channels.

[0023] In addition, the spatial reception parameters may correspond to a reception beam (e.g., a reception analog beam) of the UE, and the beam may be specified based on a spatial QCL. A QCL (or at least one element of a QCL) in the present disclosure may be read as a spatial QCL (sQCL).

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

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

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

[0027] The UE MAC layer may start a predetermined timer (which may be called a beam failure detection timer) when it receives a beam failure instance notification from the UE PHY layer. If the UE MAC layer receives a certain number of beam failure instance notifications (e.g., beamFailureInstanceMaxCount set by RRC) before the timer expires, the UE MAC layer may trigger a BFR (e.g., start one of the random access procedures described below).

[0028] The base station may determine that the UE has detected a beam failure when there is no notification from the UE (for example, the time without notification exceeds a predetermined time) or when the base station receives a predetermined signal from the UE (beam recovery request in step S104).

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

[0030] The UE may determine a beam corresponding to an RS that satisfies a predetermined condition as a new candidate beam. The UE may determine a new candidate beam based on an RS whose L1-RSRP exceeds a threshold among the set NCBI-RSs. Note that the criteria for determination are not limited to L1-RSRP. The new candidate beam may be determined using at least one of L1-RSRP, L1-RSRQ, and L1-SINR (signal-to-noise-and-interference power ratio). The L1-RSRP for SSB may be called SS-RSRP. The L1-RSRP for CSI-RS may be called CSI-RSRP. Similarly, the L1-RSRQ for SSB may be called SS-RSRQ. The L1-RSRQ for CSI-RS may be called CSI-RSRQ. Similarly, the L1-SINR for SSB may be called SS-SINR. The L1-SINR for CSI-RS may be called CSI-SINR.

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

[0032] In addition, BFD-RS, NCBI-RS, etc. may be interpreted as Radio Link Monitoring Reference Signal (RLM-RS: Radio Link Monitoring RS).

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

[0034] The BFRQ may be transmitted, for example, using a Physical Random Access Channel (PRACH). The BFRQ may include information of the new candidate beam 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, a resource index (e.g., a CSI-RS Resource Indicator (CRI), an SSB Resource Indicator (SSBRI)), etc.

[0035] Rel.15 NR supports CB-BFR (Contention-Based BFR), which is a BFR based on a contention-based random access (CFRA) procedure, and CF-BFR (Contention-Free BFR), which is a BFR based on a contention-free random access (CBRA) procedure. In CB-BFR and CF-BFR, the UE may transmit a preamble (also called an RA preamble, a random access channel (Physical Random Access Channel: PRACH), a RACH preamble, etc.) as a BFRQ using a PRACH resource.

[0036] In addition, the CF-BFR may be called a CFRA BFR, and the CB-BFR may be called a CBRA BFR.

[0037] In step S105, the base station that detects the BFRQ transmits a response signal (which may be called a BFR response, a gNB response, or the like) to the BFRQ from the UE. The response signal may include reconfiguration information (e.g., configuration information of DL-RS resources) for one or more beams.

[0038] The response signal may be transmitted, for example, in a UE common search space of a PDCCH. The response signal may be signaled using a PDCCH (DCI) having a Cyclic Redundancy Check (CRC) scrambled by an identifier of the UE (e.g., a Cell Radio Network Temporary Identifier (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.

[0039] 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. For example, the UE may detect a DCI having a CRC scrambled with a C-RNTI in a BFR search space in an individually configured CORESET.

[0040] For CB-BFR, contention resolution may be determined to be successful if the UE receives a PDCCH corresponding to a C-RNTI related to itself.

[0041] Regarding the process of step S105, a period may be set for the UE to monitor a response from a base station (e.g., a gNB) to the BFRQ. The period may be called, for example, a gNB response window, a gNB window, a beam recovery request response window, a BFRQ response window, etc. The UE may retransmit the BFRQ if no gNB response is detected within the window period.

[0042] In step S106, the UE may transmit a message indicating that the beam reconfiguration is completed to the base station, for example, via the PUCCH or the PUSCH.

[0043] In step S106, the UE may receive RRC signaling indicating a configuration of a Transmission Configuration Indication state (TCI state) to be used for the PDCCH, and may receive a MAC CE indicating activation of this configuration.

[0044] A beam recovery success (BR success) may represent, for example, reaching step S106, whereas a beam recovery failure (BR failure) may represent, for example, a predetermined number of BFRQ transmissions or expiration of a beam failure recovery timer (Beam-failure-recovery-Timer).

[0045] Note that the numbers of these steps are merely numbers for explanation, and a plurality of steps may be combined, or the order may be changed. In addition, whether or not to perform BFR may be configured in the UE using higher layer signaling.

[0046] (MAC CE based BFR) Incidentally, in future wireless communication systems (e.g., Rel. 16 and later), it is being considered that when a beam failure is detected, the occurrence of the beam failure will be notified using the uplink control channel (PUCCH) and MAC control information (MAC CE), information regarding the cell (or CC) in which the beam failure was detected, and information regarding new candidate beams will be reported.

[0047] For example, after detecting a beam failure, the UE may report the occurrence of the beam failure, information on the cell in which the beam failure was detected, and information on the new candidate beam by using one or more steps (for example, two steps) (see FIG. 2). Note that the reporting operation is not limited to two steps.

[0048] The uplink control channel allows for more flexible resource configuration in the time domain compared to the PRACH. Therefore, it is effective to use the uplink control channel (PUCCH) as a channel to be used for transmitting BFRQ. Also, the MAC CE (PUSCH) allows for more flexible resource configuration in the time domain compared to the PRACH. Therefore, it is effective to use the MAC CE (PUSCH) as a channel to be used for transmitting BFRQ.

[0049] A BFR that uses reports using MAC CE as shown in FIG. 2 may be called a MAC CE based BFR, a 2-step BFR, Rel. 16 BFR, etc., or may be called a SCell BFR because it is expected to be used to recover from beam failure of a secondary cell (SCell).

[0050] The BFR in FIG. 1 may be called a PRACH-based BFR, a PRACH-based Primary Cell (PCell) BFR, a Rel. 15 BFR, or the like.

[0051] In Fig. 2, first, the UE detects the occurrence of beam failure in a certain cell (e.g., SCell). This detection may be performed by a method similar to that of Rel. 15 BFR. In the first step (or step 1), the UE notifies the occurrence of beam failure by using an uplink control channel (PUCCH).

[0052] The UE that detects the occurrence of beam failure searches for a new candidate beam in the cell. The new candidate beam may be a beam corresponding to an RS that satisfies the above-mentioned predetermined condition. It is assumed that the UE reports at least one of information about the cell in which the beam failure is detected and information about the new candidate beam using MAC control information (e.g., MAC CE, or MAC PDU including MAC CE) in the second step (or step 2).

[0053] In the following description, the information transmitted in the first step is also referred to as first information, and the information transmitted in the second step is also referred to as second information.

[0054] The PUCCH in the first step may use a method similar to that of transmitting a scheduling request (SR). For example, the UE may transmit the first information notifying the occurrence of a beam failure in the BFR procedure by using an SR. The SR used to notify the occurrence of a beam failure may be called an SR for BFR, an SR for BFR of an SCell, a dedicated SR for SCell, a dedicated SR, a link recovery request (Link Recovery Request (LRR)), or the like.

[0055] The MAC CE (or MAC PDU) in the second step may be transmitted using uplink resources. For example, the UE may transmit the MAC CE using uplink resources allocated by the base station by transmitting a PUCCH (e.g., a dedicated SR-like PUCCH) in the first step. The MAC CE may be called a MAC CE for BFR, a BFR MAC CE, or the like.

[0056] The uplink resource may be referred to as a resource (UL-SCH resource) for a logical uplink channel (e.g., an Uplink Shared Channel (UL-SCH)) or a resource for a physical uplink channel (e.g., a Physical Uplink Shared Channel).

[0057] The format of the PUCCH used in the first step may be, for example, PUCCH format (PF) 0 or 1. Furthermore, the PUCCH transmission in the first step may be performed in a predetermined cell (for example, a primary cell (PCell), a primary secondary cell (PSCell), or another SCell in which BF is not detected). PF0 may be composed of 1 or 2 symbols. Meanwhile, PF1 may be composed of 4 or more symbols.

[0058] The PUCCH resource for BFR of the SCell in the first step may be configured commonly to all SCells included in a predetermined group (for example, the same cell group). In addition, when the UE detects a beam failure and receives a UL grant in a cell that can transmit a MAC CE for BFR before transmitting the PUCCH (or SR) in the first step, the UE may not transmit the PUCCH in the first step.

[0059] The MAC CE transmission (PUSCH transmission) in the second step may be performed in the predetermined cell (for example, a PCell, a PSCell, or another SCell).

[0060] When the UE detects a beam failure but is unable to identify a new candidate beam, the UE may include information on the cell in which the beam failure is detected in the MAC CE in the second step, and may not include an index of the new candidate beam. The case where a new candidate beam cannot be identified may be, for example, when there is no reference signal whose received power (RSRP) is equal to or greater than a predetermined value.

[0061] After transmitting the BFR MAC CE, the UE receives a BFR response that may correspond to a DCI that schedules a PUSCH transmission with the same HARQ process number as that used for the transmission of the first PUSCH carrying the BFR MAC CE, and that has a New Data Indicator (NDI) field value toggled (in other words, schedules a new transmission).

[0062] In the PRACH-based BFR of Rel.15, it is specified that after the RA procedure for BFR is completed (may be called after BFR, after BFR completion, etc.), before an explicit beam is set / activated, the QCL assumption of a specific PDCCH and the spatial relationship of a specific PUCCH are updated based on the new candidate beam. This prevents a situation in which a failed beam continues to be used and proper communication cannot be performed.

[0063] However, the spatial relationship (beam) update for UL channels / signals after SCell BFR has not yet been studied. For example, it is not clear how to update the spatial relationship of the sounding reference signal (SRS). If the spatial relationship is not applied properly, the throughput, communication quality, etc. may be degraded.

[0064] Therefore, the present inventors have devised a method for performing suitable UL transmission after BFR.

[0065] 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.

[0066] In the present disclosure, "A / B" and "at least one of A and B" may be read as interchangeable.

[0067] (Wireless communication method) In one embodiment of the present disclosure, for an SCell(s) in which a beam failure (BF) is detected, the UE may schedule a PUSCH transmission having the same HARQ process number as that used for transmitting a first PUSCH carrying a MAC CE for BFR, and may perform at least one of the following operations (1)-(3) 28 symbols or more after the final symbol of a PDCCH reception in a DCI format having a toggled New Data Indicator (NDI) field value.

[0068] (1) Index q new The MAC CE monitors the PDCCH in all CORESETs of the SCell(s) indicated by the MAC CE, using the same QCL parameters as the antenna ports for the SCell(s).

[0069] (2) Index q newThe same spatial domain filter is used as for periodic CSI-RS or SSB reception for the PUCCH, and the formula (Subclause 7.2.1 of TS 38.213) used to determine the PUCCH transmission power is used to include q u =0, q d =q new , l=0, and transmits the PUCCH on the PUCCH-SCell using the transmission power determined by applying l=0 (provided that the following three conditions are met: PUCCH spatial relation information (PUCCH-SpatialRelationInfo) for the PUCCH has been provided to the UE, no LRR has been transmitted on the PUCCH-SCell, and the PUCCH-SCell is included in the SCell(s) indicated by the MAC CE).

[0070] In addition, in normal cases, q u q may be a P0 ID for PUCCH (p0-PUCCH-Id) indicating P0 for PUCCH (P0-PUCCH) in the P0 set for PUCCH (p0-Set). q may be referred to as a power control adjustment state index, a closed loop index, etc. d may be an index of a pathloss reference RS (eg, set by PUCCH-PathlossReferenceRS).

[0071] Also, q new may be an index for a new candidate beam (e.g., SSB / CSI-RS) that the UE reports to the network in the BFR procedure.

[0072] (3) Index q new The same spatial domain filter is used as for periodic CSI-RS or SSB reception for q, and the formula used to determine the SRS transmission power (Subclause 7.3.1 of TS 38.213) is used. d =q new, l=0, transmit an aperiodic SRS (A-SRS) resource in a particular cell, provided that spatial relationship information (spatialRelationInfo) for the A-SRS resource has been provided to the UE.

[0073] The specific cell in (3) above may be a cell that satisfies at least one of the following: Index q new SCell of (in other words, index q new (the cell receiving the CSI-RS and SSB corresponding to the - SCell for which BF was detected and reported by the BFR MAC CE above, All SCells for which SCell BFR (or SCell beam failure detection) is configured, All SCells included in the PUCCH group (PUCCH cell group) to which the PUCCH-SCell in (2) above belongs, All configured SCells, All active SCells, All configured / active SCells in the intra-frequency band (or within the band) to which the SCell for which BFR is implemented belongs.

[0074] Regarding PUCCH, among the SCells using SCell BFR, only PUCCH-SCell can transmit PUCCH. On the other hand, regarding SRS, since it can be transmitted by any SCell, it is preferable to clarify the specific cell in this way.

[0075] The A-SRS resource in (3) above may be an A-SRS resource included in an SRS resource set in which the usage of an upper layer parameter is set to a specific usage, and the specific usage may be at least one of a codebook, a non-codebook, an antenna switching, and a beam management, for example.

[0076] If the A-SRS resource in (3) above corresponds to an SRS for codebook / non-codebook use, the UE appropriately adjusts the beam (spatial relationship) of the PUSCH of the SCell in which the BF is detected. new Because the SRS for codebook / non-codebook use may be used to determine a precoder for codebook-based or non-codebook-based PUSCH transmission based on an SRS Resource Indicator (SRI).

[0077] The UE may assume that for A-SRS resources that correspond to usages other than the specific usage, the spatial relationship is explicitly updated using the MAC CE.

[0078] In addition, the SubCarrier Spacing (SCS) setting for the 28 symbols may correspond to the smallest SCS setting among the SCS setting of the active Downlink Bandwidth Part (DL BWP) for receiving the PDCCH and the SCS setting of the active DL BWP for the SCell(s) in which the beam failure is detected.

[0079] The PUCCH / SRS transmission in (2) and (3) above is performed with index q newIt may also mean transmission using the same spatial domain filter as the spatial domain receive filter for receiving a reference signal (e.g., SSB, CSI-RS) corresponding to the new candidate beam (transmission using a spatial domain filter corresponding to the new candidate beam). According to (2) and (3) above, after 28 symbols from the BFR response, the spatial relationship of the PUCCH / SRS can be updated to the spatial relationship corresponding to the new candidate beam.

[0080] In the above (2), "PUCCH spatial relation information (PUCCH-SpatialRelationInfo) for the PUCCH is provided to the UE" may be read as "the default spatial relation is not applied to the PUCCH".

[0081] In the above (3), “spatial relationship information (spatialRelationInfo) for the A-SRS resource is provided to the UE” may be read as “no default spatial relationship is applied to the A-SRS resource.”

[0082] 3 is a diagram illustrating an example of spatial relationship update after SCell BFR according to an embodiment. In this example, a UE transmits and receives to and from a PCell for SCell BFR related to BF detected on a certain SCell. In addition, a base station forming a PCell and a base station forming a SCell may be different or the same.

[0083] In this example, after 28 symbols from the final symbol of the PDCCH reception of the BFR response (in the DCI format), the UE detects that the beam for PUCCH / SRS transmission is the same as the new candidate beam (new beam) reported by the MAC CE (index q new (applying the same spatial domain filter as for periodic CSI-RS or SSB reception for .

[0084] It may be assumed that the UE does not perform the above operations (1) to (3) until 28 symbols have passed since the final symbol of the PDCCH reception of the BFR response (in the DCI format).

[0085] According to the embodiment of the present disclosure described above, the beam recovered by the SCell BFR can be appropriately used for the subsequent PUCCH / SRS transmission.

[0086] <Other> The "28 symbols" in the above embodiment may be read as "X symbols" (or a predetermined number of symbols). The X (predetermined number) may be determined in advance by a specification, may be set by higher layer signaling, or may be determined based on UE capabilities (e.g., UE capabilities related to BFR).

[0087] In addition, the phrase "after 28 symbols" in the present disclosure may be read as "for a certain period of time after 28 symbols." The certain period of time may be, for example, a period until a spatial relationship is set / activated for PUCCH / SRS.

[0088] The above embodiment may be applied to a UE in which a specific parameter is configured by RRC. The specific parameter may be, for example, a parameter that enables BFR (or SCell BFR) of Rel. 16.

[0089] The above embodiment may be applied to a UE that reports specific capability information to a network. The capability information may be, for example, capability related to QCL assumption / spatial relationship after SCell BFR. When implementing SCell BFR, the UE that reported the capability information may perform at least one of the above operations (1)-(3) after 28 symbols from the final symbol of BFR response reception.

[0090] In addition, the "A-SRS resource" in the above embodiment may be interpreted as at least one of a Periodic SRS (P-SRS) resource, a Semi-Persistent SRS (SP-SRS) resource, and an A-SRS resource.

[0091] In addition, the SCell in each of the above embodiments may be interpreted as at least one of a special cell (SpCell) and an SCell. The SpCell may be interpreted as a PCell / PSCell and vice versa, or may mean a cell other than the PCell / PSCell.

[0092] (Wireless communication systems) A 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 of these methods.

[0093] 4 is a diagram showing 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), 5th generation mobile communication system New Radio (5G NR), or the like, which are specified by the Third Generation Partnership Project (3GPP).

[0094] Furthermore, the wireless communication system 1 may support dual connectivity between a plurality of 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)), and the like.

[0095] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (MN) and the NR base station (gNB) is the secondary node (SN). In NE-DC, the NR base station (gNB) is the MN and the LTE (E-UTRA) base station (eNB) is the SN.

[0096] The wireless communication system 1 may support dual connectivity between multiple base stations in the same RAT (for example, dual connectivity in which both the MN and the SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0097] 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 arranged in the macrocell C1 and form a small cell C2 that is narrower than the macrocell C1. A user terminal 20 may be located in at least one of the cells. The arrangement and number of each cell and user terminal 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 a base station 10.

[0098] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CC) and dual connectivity (DC).

[0099] Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band above 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a frequency band higher than FR2.

[0100] Furthermore, the user terminal 20 may perform communication in each CC using at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD).

[0101] The multiple base stations 10 may be connected by wire (e.g., optical fiber conforming to Common Public Radio Interface (CPRI), 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.

[0102] 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 at least one of, for example, an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), and the like.

[0103] The user terminal 20 may be a terminal compatible with at least one of communication methods such as LTE, LTE-A, and 5G.

[0104] In the wireless communication system 1, a wireless access scheme based on Orthogonal Frequency Division Multiplexing (OFDM) may be used. For example, in at least one of the downlink (DL) and the uplink (UL), 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), etc. may be used.

[0105] The radio access scheme may be called a waveform. In the wireless communication system 1, other radio access schemes (for example, other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0106] 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 a downlink channel.

[0107] In addition, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), etc. may be used as an uplink channel.

[0108] 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).

[0109] 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 of at least one of the PDSCH and the PUSCH.

[0110] In addition, DCI for scheduling PDSCH may be called DL assignment, DL DCI, etc., and DCI for scheduling PUSCH may be called UL grant, UL DCI, etc. In addition, PDSCH may be replaced with DL data, and PUSCH may be replaced with UL data.

[0111] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources to search for DCI. The search space corresponds to a search region and a search method for PDCCH candidates. One CORESET may be associated with one or multiple search spaces. The UE may monitor a CORESET associated with a certain search space based on the search space configuration.

[0112] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be called a search space set. Note that the terms "search space," "search space set," "search space setting," "search space set setting," "CORESET," and "CORESET setting" in the present disclosure may be read as interchangeable terms.

[0113] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), delivery acknowledgement information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and a scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0114] In the present disclosure, a downlink, an uplink, etc. may be expressed without adding "link." Also, various channels may be expressed without adding "Physical" to the beginning of the channels.

[0115] 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.

[0116] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including the SS (PSS, SSS) and the PBCH (and the DMRS for the PBCH) may be called an SS / PBCH block, an SS Block (SSB), or the like. In addition, the SS, SSB, and the like may also be called a reference signal.

[0117] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), etc. may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may be called a user equipment specific reference signal (UE-specific reference signal).

[0118] (base station) 5 is a diagram showing an example of the configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140 may be provided.

[0119] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and the base station 10 may be assumed to have other functional blocks necessary for wireless communication. Some of the processes of each unit described below may be omitted.

[0120] The control unit 110 performs overall control of the base station 10. The control unit 110 can be configured with 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.

[0121] 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 transmission and reception unit 120, the transmission and reception 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 transmission and reception unit 120. The control unit 110 may perform call processing (setting, release, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0122] 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.

[0123] 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, an RF unit 122, and a measurement unit 123.

[0124] The transmitting / receiving antenna 130 can be composed of an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0125] 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.

[0126] The transceiver 120 may form at least one of a transmission beam and a reception beam using digital beamforming (eg, precoding), analog beamforming (eg, phase rotation), or the like.

[0127] The transceiver 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0128] The transceiver 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.

[0129] The transceiver unit 120 (RF unit 122) may perform modulation to a radio frequency band, filtering, amplification, and the like on the baseband signal, and transmit the radio frequency band signal via the transceiver antenna .

[0130] 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 signal received by the transceiver antenna .

[0131] 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.

[0132] 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.

[0133] 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) for the user terminal 20, control plane data, etc.

[0134] 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.

[0135] In addition, the transceiver unit 120 may transmit a response to the report of the candidate beam to the user terminal 20 in a beam failure recovery (BFR) procedure of the secondary cell.

[0136] The control unit 110 may assume that the user terminal 20 will transmit a sounding reference signal (SRS) resource in a particular cell using a spatial domain filter for the reported candidate beam after a certain period of time from the final symbol of the reception of the response.

[0137] (User terminal) 6 is a diagram showing an example of the configuration of a user terminal according to an 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.

[0138] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and the user terminal 20 may be assumed to have other functional blocks necessary for wireless communication. Some of the processes of each unit described below may be omitted.

[0139] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured with 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.

[0140] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may control transmission / reception, measurement, etc. using the transmission / reception unit 220 and the transmission / reception antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transmission / reception unit 220.

[0141] The transmitting / receiving 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 transmitting / receiving unit 220 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transmitting / receiving circuit, and the like, which are described based on common understanding in the technical field related to the present disclosure.

[0142] 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.

[0143] The transmitting / receiving antenna 230 can be composed of an antenna described based on common understanding in the technical field to which this disclosure pertains, such as an array antenna.

[0144] 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.

[0145] The transceiver 220 may form at least one of a transmission beam and a reception beam using digital beamforming (eg, precoding), analog beamforming (eg, phase rotation), or the like.

[0146] 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.

[0147] The transceiver 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 sequence to be transmitted, and output a baseband signal.

[0148] Whether or not to apply the DFT process may be based on the setting of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver 220 (transmission processor 2211) may perform the DFT process as the transmission process to transmit the channel using a DFT-s-OFDM waveform, and may not perform the DFT process as the transmission process if transform precoding is enabled for the channel.

[0149] The transceiver unit 220 (RF unit 222) may perform modulation to a radio frequency band, filtering, amplification, and the like on the baseband signal, and transmit the radio frequency band signal via the transceiver antenna 230.

[0150] 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 signal received by the transceiver antenna 230.

[0151] The transceiver 220 (reception processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, and acquire user data, etc.

[0152] 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.

[0153] In addition, the transmitting section and the receiving section of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving section 220, the transmitting / receiving antenna 230, and the transmission path interface 240.

[0154] In addition, the transceiver unit 220 may receive a response (BFR response (PDCCH related thereto)) to a report of a candidate beam (e.g., BFR MAC CE) in a Beam Failure Recovery (BFR) procedure of a secondary cell.

[0155] The control unit 210 may assume that a sounding reference signal (SRS) resource is transmitted in a particular cell using a spatial domain filter for the reported candidate beam after a certain period of time from the last symbol of the reception of the response. The certain period of time may be, for example, 28 symbols, X symbols, etc. The SRS resource may be an A- / SP- / P-SRS resource.

[0156] The particular cell may be a secondary cell from which the candidate beam is transmitted.

[0157] The specific cell may be all secondary cells included in a cell group (PUCCH group) to which a secondary cell (PUCCH-SCell) belongs, the uplink control channel (PUCCH) of which is transmitted using a spatial domain filter for the reported candidate beam after a certain period from the final symbol of the reception of the response.

[0158] The SRS resource may be an SRS resource included in an SRS resource set whose usage is set to codebook or non-codebook.

[0159] (Hardware configuration) The block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. The method of realizing each functional block is not particularly limited. That is, each functional block may be realized by using one device that is physically or logically combined, or may be realized by using two or more devices that are physically or logically separated and directly or indirectly connected (for example, by wire, wirelessly, etc.). The functional blocks may be realized by combining the one device or the multiple devices with software.

[0160] 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, selection, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs the function of transmission may be called a transmitting unit, a transmitter, and the like. In either case, as described above, the method of realization is not particularly limited.

[0161] For example, a base station, a user terminal, etc. in an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 7 is a diagram showing an example of a hardware configuration of a base station and a user terminal according to an embodiment. The above-mentioned 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.

[0162] In this disclosure, the terms "apparatus," "circuit," "device," "section," "unit," and the like can be read interchangeably. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0163] For example, although only one processor 1001 is shown, there may be multiple processors. Also, the processes may be performed by one processor, or the processes may be performed by two or more processors simultaneously, sequentially, or in other manners. Also, the processor 1001 may be implemented by one or more chips.

[0164] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading a specific software (program) onto hardware such as a processor 1001 and a memory 1002, so that the processor 1001 performs calculations, controls communications via a communication device 1004, and controls at least one of reading and writing of data in the memory 1002 and the storage 1003.

[0165] The processor 1001, for example, operates an operating system to control the entire computer. The processor 1001 may be configured with a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transmission / reception unit 120 (220), etc. may be realized by the processor 1001.

[0166] Moreover, the processor 1001 reads out 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 according to the programs. As the programs, programs that cause a computer to execute at least a part of the operations described in the above-mentioned embodiments are used. For example, the control unit 110 (210) may be realized by a control program stored in the memory 1002 and operated by the processor 1001, and the other functional blocks may be realized in a similar manner.

[0167] The memory 1002 is a computer-readable recording medium, and may be configured by at least one of, for example, a Read Only Memory (ROM), an Erasable Programmable ROM (EPROM), an Electrically EPROM (EEPROM), a Random Access Memory (RAM), and other suitable storage media. The memory 1002 may be called a register, a cache, a main memory (primary storage device), and the like. The memory 1002 can store a program (program code), a software module, and the like that is executable to implement a wireless communication method according to an embodiment of the present disclosure.

[0168] Storage 1003 is a computer-readable recording medium and may be constituted by at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disk (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disk, a Blu-ray disk), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, stick, key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as an auxiliary storage device.

[0169] The communication device 1004 is hardware (transmission / reception device) for performing communication between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., in order 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.

[0170] 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 performs output to the outside. The input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0171] In addition, 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.

[0172] 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), a field programmable gate array (FPGA), etc., and some or all of the functional blocks may be realized using the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0173] (Modification) In addition, the terms explained in this disclosure and the terms necessary for understanding this 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 read as mutually interchangeable. A signal may also be a message. A reference signal may also be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applied standard. A component carrier (CC) may also be called a cell, a frequency carrier, a carrier frequency, etc.

[0174] 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.

[0175] Here, the numerology may be a communication parameter applied to at least one of the transmission and reception of a certain signal or channel. The numerology may indicate at least one of, for example, a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), a number of symbols per TTI, a radio frame structure, a specific filtering process performed by a transceiver in the frequency domain, and a specific windowing process performed by a transceiver in the time domain.

[0176] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.) in the time domain. A slot may also be a time unit based on numerology.

[0177] A slot may include multiple minislots. Each minislot may be composed of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may be composed 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.

[0178] A radio frame, a subframe, a slot, a minislot, and a symbol each represent a time unit for transmitting a signal. A different name may be used for 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 read as interchangeable with each other.

[0179] For example, one subframe may be called a TTI, multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in the 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.

[0180] Here, TTI refers to, for example, the minimum 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.

[0181] 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) in which a transport block, a code block, a code word, etc. are actually mapped may be shorter than the TTI.

[0182] In addition, when one slot or one minislot is called TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit of scheduling. Also, the number of slots (minislots) constituting the minimum time unit of scheduling may be controlled.

[0183] A TTI having a time length of 1 ms may be called a normal TTI (TTI in 3GPP Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a minislot, a subslot, a slot, etc.

[0184] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length exceeding 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0185] 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 the numerology, and may be, for example, 12. The number of subcarriers included in an RB may be determined based on the numerology.

[0186] 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 one TTI, one subframe, etc. may be composed of one or more resource blocks.

[0187] In addition, one or more RBs may be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0188] 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.

[0189] A Bandwidth Part (BWP), which may also be referred to as a fractional bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a numerology on a carrier, where the common RBs may be identified by the index of the RBs relative to a common reference point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0190] The BWP may include a UL BWP (a BWP for UL) and a DL BWP (a BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0191] 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 replaced with "BWP".

[0192] The above-mentioned structures of radio frames, subframes, slots, minislots, and symbols 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, and other configurations can be changed in various ways.

[0193] In addition, the information, parameters, etc. described in the present disclosure may be represented using absolute values, may be represented using relative values ​​from a predetermined value, or may be represented using other corresponding information. For example, a radio resource may be indicated by a predetermined index.

[0194] The names used for parameters and the like in this disclosure are not limiting in any way. Furthermore, the formulas 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 limiting in any way.

[0195] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, the 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.

[0196] 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.

[0197] Input and output information, signals, etc. may be stored in a specific location (e.g., memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added to. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0198] 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.

[0199] The physical layer signaling may be called Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. The RRC signaling may be called an RRC message, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc. The MAC signaling may be notified, for example, by using a MAC Control Element (CE).

[0200] 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).

[0201] The determination may be made based on a value represented by a single bit (0 or 1), a Boolean value represented as true or false, or by comparing numerical values ​​(e.g., with a predetermined value).

[0202] 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.

[0203] Additionally, software, instructions, information, etc. may be transmitted or received over a transmission medium. For example, if the 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, etc.), then these wired and / or wireless technologies are included within the definition of transmission media.

[0204] 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).

[0205] In this 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," and the like may be used interchangeably.

[0206] In this disclosure, terms such as "Base Station (BS)", "radio base station", "fixed station", "NodeB", "eNB (eNodeB)", "gNB (gNodeB)", "access point", "Transmission Point (TP)", "Reception Point (RP)", "Transmission / Reception Point (TRP)", "panel", "cell", "sector", "cell group", "carrier", "component carrier", etc. may be used interchangeably. A base station may also be referred to by terms such as a macro cell, a small cell, a femto cell, a pico cell, etc.

[0207] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the entire coverage area of ​​the base station can be partitioned into multiple smaller areas, and each smaller area can also be provided with communication services by a base station subsystem (e.g., a small base station for indoor use (Remote Radio Head (RRH))). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or a base station subsystem that provides communication services in this coverage.

[0208] In this disclosure, the terms "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. may be used interchangeably.

[0209] 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.

[0210] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, etc. At least one of the base station and the mobile station may be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned moving 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 include a device that does not necessarily move during communication operation. 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.

[0211] Furthermore, the base station in the present disclosure may be read as a user terminal. For example, each aspect / embodiment 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 a plurality of 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, "side"). For example, an uplink channel, a downlink channel, etc. may be read as a side channel.

[0212] Similarly, the user terminal in the present disclosure may be interpreted as a base station. In this case, the base station 10 may be configured to have the functions of the user terminal 20 described above.

[0213] In the present disclosure, an operation performed by a base station may be performed by its upper node in some cases. It is clear that in a network including one or more network nodes having base stations, various operations performed for communication with terminals may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME) and a Serving-Gateway (S-GW)), or a combination thereof.

[0214] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched according to implementation. In addition, the processing procedures, sequences, flow charts, etc. of each aspect / embodiment described in this disclosure may be reordered 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.

[0215] Each aspect / embodiment described in the present disclosure may be implemented using any of a wide variety of standards, including Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (x is, for example, an integer or a decimal point)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE The present invention may be applied to systems using 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), other appropriate wireless communication methods, next-generation systems that are based on these, etc. Also, the present invention may be applied to a combination of multiple systems (for example, a combination of LTE or LTE-A and 5G).

[0216] 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."

[0217] Any reference to an element using a designation such as "first," "second," etc., used in this disclosure 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 precede the second element in some way.

[0218] 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, and the like.

[0219] A "determining" may also be considered to be "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in a memory), etc.

[0220] Also, "determination" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. That is, "determination" may be considered to be "deciding" to perform some action.

[0221] Additionally, "judgment (decision)" may be interpreted as "assuming," "expecting," "considering," etc.

[0222] The "maximum transmit power" in this disclosure may mean the maximum value of transmit power, may mean the nominal UE maximum transmit power, or may mean the rated UE maximum transmit power.

[0223] 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 the elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access."

[0224] 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, and the like, as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, and the like, as some non-limiting and non-exhaustive examples.

[0225] 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."

[0226] 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." Further, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0227] In this disclosure, where articles have been 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.

[0228] 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 as modified and altered forms without departing from the spirit and scope of the invention defined based on the description of the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the invention according to the present disclosure.

[0229] This application is based on Japanese Patent Application No. 2020-094109, filed on May 29, 2020, the contents of which are incorporated herein in their entirety.

Claims

1. A receiver that receives a downlink control information (DCI) format in response to a report of an index related to a channel state reference signal (CSI-RS) or a synchronization signal block (SSB) using a medium access control element (MAC CE) in a beam failure recovery (BFR) procedure of a secondary cell; a control unit that schedules a PUSCH transmission having the same HARQ process number as a PUSCH used for transmitting the first Physical Uplink Shared Channel (PUSCH) that transmits the MAC CE, and controls transmission of an SRS for an SRS resource set whose purpose is beam management or antenna switching, using a spatial domain filter that is the same as a spatial domain filter corresponding to the index, from 28 symbols after a final symbol of reception of a Physical Downlink Control Channel (PDCCH) in the DCI format having a New Data Indicator (NDI) field value that is toggled, and using a transmission power of the SRS determined using an equation for determining a transmission power of the SRS based on the index.

2. The terminal of claim 1 , wherein when the application is beam management, the SRS is a non-periodic SRS.

3. receiving a downlink control information (DCI) format in response to a report of a channel status indicator (CSI-RS) or a synchronization signal block (SSB) index using a medium access control element (MAC CE) in a beam failure recovery (BFR) procedure of a secondary cell; scheduling transmission of a first Physical Uplink Shared Channel (PUSCH) that transmits the MAC CE, the PUSCH having the same HARQ process number as that used for transmitting the PUSCH; and controlling transmission of a Sounding Reference Signal (SRS) for an SRS resource set whose purpose is beam management or antenna switching, using a spatial domain filter that is the same as a spatial domain filter corresponding to the index, from 28 symbols onward from a final symbol of reception of a Physical Downlink Control Channel (PDCCH) in the DCI format having a New Data Indicator (NDI) field value that is toggled, and using a transmission power of the SRS determined using an equation for determining a transmission power of the SRS based on the index.

4. A system including a terminal and a base station, The terminal includes: A receiver that receives a downlink control information (DCI) format in response to a report of an index related to a channel state reference signal (CSI-RS) or a synchronization signal block (SSB) using a medium access control element (MAC CE) in a beam failure recovery (BFR) procedure of a secondary cell; a control unit that schedules a PUSCH transmission having the same HARQ process number as that used for transmitting a first Physical Uplink Shared Channel (PUSCH) that transmits the MAC CE, and controls transmission of an SRS for an SRS resource set whose purpose is beam management or antenna switching, using a spatial domain filter that is the same as a spatial domain filter corresponding to the index, and using a transmission power of the SRS determined using an equation for determining a transmission power of the SRS based on the index, from 28 symbols onward from a final symbol of reception of a Physical Uplink Control Channel (PDCCH) in the DCI format having a toggled New Data Indicator (NDI) field value, The base station, The system includes a transmitter that transmits the response to the terminal.

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