Terminal, base station, and measurement method

Abstract

This terminal comprises: a reception unit for receiving downlink control information from a base station; and a control unit for executing, on the basis of a trigger due to the downlink control information, measurement for radio link monitoring or beam failure recovery using a non-periodic reference signal received from the base station.

Description

[Technical field]

[0001] The present invention relates to a terminal, a base station, and a measurement method in a wireless communication system. [Background technology]

[0002] For NR (New Radio) (also called "5G"), the successor system to LTE (Long Term Evolution), technologies that satisfy the requirements of a large-capacity system, high data transmission speed, low latency, simultaneous connection of many terminals, low cost, power saving, etc. are being considered (for example, Non-Patent Document 1). In addition, for NR, the use of high frequency bands such as 52.6 to 114.25 GHz is being considered.

[0003] In addition, in order to expand the frequency band, the NR system supports the use of frequency bands different from the frequency bands licensed to telecommunications carriers (operators) (also called unlicensed bands, unlicensed carriers, or unlicensed CCs). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 38.300 V16.4.0 (2020-12) [Non-Patent Document 2] 3GPP TS 38.331 V16.3.0 (2020-12) [Non-Patent Document 3] 3GPP TS 38.213 V16.4.0 (2020-12) [Non-Patent Document 4] 3GPP TS 38.321 V16.3.0 (2020-12) [Non-Patent Document 5] 3GPP TS 38.214 V16.4.0 (2020-12) Summary of the Invention [Problem to be solved by the invention]

[0005] In NR, various functions for detecting radio link failures and their recovery are specified (e.g., Non-Patent Documents 2 to 5). In addition, in NR, various functions for detecting beam failures and their recovery are also specified (e.g., Non-Patent Documents 2 to 5).

[0006] However, terminals that comply with existing NR regulations, which are intended for frequency bands up to 52.6 GHz, may not be able to properly detect and recover radio link / beam failures in high frequency bands such as 52.6 to 114.25 GHz, where the use of unlicensed bands is expected.

[0007] The present invention has been made in consideration of the above-mentioned points, and has an object to provide a technique that enables a terminal to appropriately perform fault detection and recovery in a wireless communication system. [Means for solving the problem]

[0008] According to the disclosed technology, a receiving unit that receives downlink control information from a base station; a control unit that performs measurement for radio link monitoring or beam failure recovery using a non-periodic reference signal received from the base station based on a trigger by the downlink control information, The control unit determines, based on a format of the downlink control information, that the non-periodic reference signal is a reference signal to be used for radio link monitoring or beam failure recovery. A terminal is provided. Effect of the Invention

[0009] The disclosed technology provides a technology that enables a terminal to appropriately detect a failure and perform recovery in a wireless communication system. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating a wireless communication system according to an embodiment of the present invention. [Diagram 2] 1 is a diagram illustrating a wireless communication system according to an embodiment of the present invention. [Diagram 3] FIG. 13 is a diagram showing an example of a band. [Figure 4] FIG. 1 is a diagram showing the relationship between SCS and symbol length. [Diagram 5] FIG. 2 is a diagram showing an example of a basic procedure according to an embodiment of the present invention. [Figure 6] FIG. 1 is a diagram illustrating an example of an RLM / RLF procedure. [Figure 7] FIG. 1 is a diagram for explaining Rel-15 BFR. [Figure 8] FIG. 1 is a diagram for explaining Rel-16 BFR. [Figure 9] FIG. 1 is a diagram showing an example of a specification for RLM / BFD. [Figure 10] FIG. 1 is a diagram showing an example of a specification for BFR. [Figure 11] FIG. 13 is a diagram for explaining the transmission status of CSI-RS / SSB when performing LBT. [Figure 12] FIG. 13 is a diagram showing an example of an R-16 aperiodic CSI report triggering procedure. [Figure 13] FIG. 1 is a diagram showing an example of a specification. [Figure 14] FIG. 13 is a diagram showing an example of a specification in the third embodiment. [Figure 15] FIG. 13 is a diagram showing an example of a specification in the third embodiment. [Figure 16] FIG. 13 is a diagram showing an example of a specification in the third embodiment. [Figure 17] FIG. 13 is a diagram illustrating an example of setting information in the third embodiment. [Figure 18] FIG. 13 is a diagram illustrating an example of setting information in the third embodiment. [Figure 19] FIG. 13 is a diagram showing an example of a specification in the third embodiment. [Figure 20]FIG. 13 is a diagram showing an example of a specification in the third embodiment. [Figure 21] FIG. 13 is a diagram showing an example of a specification in the fourth embodiment. [Figure 22] 2 is a diagram illustrating an example of a functional configuration of a base station 10 according to an embodiment of the present invention. [Figure 23] 2 is a diagram illustrating an example of a functional configuration of a terminal 20 according to an embodiment of the present invention. [Figure 24] 2 is a diagram illustrating an example of a hardware configuration of a base station 10 or a terminal 20 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0012] Existing technology is used as appropriate for the operation of the wireless communication system according to the embodiment of the present invention. The existing technology is, for example, the existing NR. The wireless communication system (base station 10 and terminal 20) in this embodiment basically operates in accordance with existing regulations (e.g., Non-Patent Documents 1 to 5). However, in order to solve problems when using a high frequency band or an unlicensed band, the base station 10 and terminal 20 also perform operations that are not in the existing regulations. In the explanation of the embodiment described below, operations that are not in the existing regulations are mainly explained. Note that all numerical values ​​described below are examples.

[0013] Furthermore, in the embodiment of the present invention, the duplexing method may be a time division duplex (TDD) method, a frequency division duplex (FDD) method, or another method (for example, flexible duplex, etc.).

[0014] Furthermore, in the embodiment of the present invention, when radio parameters, etc. are "configured," this may mean that predetermined values ​​are pre-configured, or that radio parameters notified from base station 10 or terminal 20 are configured.

[0015] In the embodiments described below, Apriodic CSI-RS is taken as an example of a reference signal used for RLM / BFR, but the aperiodic reference signal to which the technology according to the present invention can be applied is not limited to Apriodic CSI-RS. For example, an aperiodic synchronization signal or a reference signal other than SCI-RS may be used as an aperiodic reference signal to which the technology according to the present invention can be applied.

[0016] (System Configuration)

[0017] Fig. 1 is a diagram for explaining a wireless communication system in an embodiment of the present invention. As shown in Fig. 1, the wireless communication system in the embodiment of the present invention includes a base station 10 and a terminal 20. Although Fig. 1 shows one base station 10 and one terminal 20, this is an example, and there may be a plurality of each.

[0018] The base station 10 is a communication device that provides one or more cells and performs wireless communication with the terminals 20. The physical resources of a wireless signal are defined in the time domain and the frequency domain.

[0019] OFDM is used as the wireless access method. In the frequency domain, subcarrier spacing (SCS) of at least 15 kHz, 30 kHz, 120 kHz, and 240 kHz are supported. Regardless of the SCS, a resource block is composed of a predetermined number of consecutive subcarriers (for example, 12).

[0020] When performing initial access, terminal 20 detects an SSB (SS / PBCH block) and identifies the SCS in the PDCCH and PDSCH based on the PBCH included in the SSB.

[0021] In the time domain, a slot is made up of multiple OFDM symbols (for example, 14, regardless of the subcarrier spacing). Hereinafter, OFDM symbols are called "symbols." A slot is a scheduling unit. Subframes of 1 ms duration are defined, and a frame consisting of 10 subframes is defined. The number of symbols per slot is not limited to 14.

[0022] As shown in Fig. 1, the base station 10 transmits control information or data to the terminal 20 in DL (Downlink) and receives control information or data from the terminal 20 in UL (Uplink). Both the base station 10 and the terminal 20 are capable of transmitting and receiving signals by performing beamforming. In addition, both the base station 10 and the terminal 20 are capable of applying communication by MIMO (Multiple Input Multiple Output) to DL or UL. In addition, both the base station 10 and the terminal 20 may communicate via a SCell (Secondary Cell) and a PCell (Primary Cell) by CA (Carrier Aggregation).

[0023] The terminal 20 is a communication device equipped with a wireless communication function, such as a smartphone, a mobile phone, a tablet, a wearable terminal, a communication module for M2M (Machine-to-Machine), etc. As shown in Fig. 1, the terminal 20 receives control information or data from the base station 10 via DL and transmits control information or data to the base station 10 via UL, thereby using various communication services provided by the wireless communication system.

[0024] The terminal 20 can perform carrier aggregation, which aggregates multiple cells (multiple CCs (component carriers)) to communicate with the base station 10. In carrier aggregation, one PCell (primary cell) and one or more SCells (secondary cells) are used. Also, a PUCCH-SCell having a PUCCH may be used.

[0025] Fig. 2 shows a configuration example of a wireless communication system when NR-Dual connectivity (NR-DC) is executed. As shown in Fig. 2, a base station 10A serving as a Master Node (MN) and a base station 10B serving as a Secondary Node (SN) are provided. The base station 10A and the base station 10B are each connected to a core network. The terminal 20 communicates with both the base station 10A and the base station 10B.

[0026] A cell group provided by the base station 10A, which is an MN, is called an MCG (Master Cell Group), and a cell group provided by the base station 10B, which is an SN, is called an SCG (Secondary Cell Group). In addition, in a DC, an MCG is composed of one PCell and one or more SCells, and an SCG is composed of one PSCell (Primary SCell) and one or more SCells. In this specification, a CC (component carrier) and a cell may be used synonymously. In addition, a PCell and a PSCell may be called an SPCell.

[0027] In the wireless communication system according to the present embodiment, when an unlicensed band is used, LBT (Listen Before Talk) is executed. The base station 10 or the terminal 20 senses a signal, and transmits when the sensing result is idle, and does not transmit when the sensing result is busy. Note that LBT is not necessarily performed in an unlicensed band, and there may be cases where LBT is not performed in an unlicensed band.

[0028] (Regarding frequency bands) Fig. 3 shows an example of frequency bands used in the existing NR and frequency bands used in the wireless communication system according to the present embodiment. There are two frequency bands (which may be called frequency ranges) in the existing NR: FR1 (0.41 GHz to 7.125 GHz) and FR2 (24.25 GHz to 52.6 GHz). As shown in Fig. 3, FR1 supports 15 kHz, 30 kHz, and 60 kHz as the SCS, and supports 5 to 100 MHz as the bandwidth (BW). FR2 supports 60 kHz, 120 kHz, and 240 kHz (only SSB) as the SCS, and supports 50 to 400 MHz as the bandwidth (BW).

[0029] In the wireless communication system according to the present embodiment, it is assumed that a frequency band higher than 52.6 GHz (for example, 52.6 GHz to 114.25 GHz) that is not used in the existing NR will also be used. This frequency band may be referred to as FR4.

[0030] In addition, in this embodiment, it is assumed that an SCS wider than the existing SCS will be used as the frequency band is expanded as described above. For example, an SCS of 480 kHz or an SCS wider than 480 kHz will be used as the SCS for SSB and PDCCH / PDSCH.

[0031] In the high frequency band, it is expected that multiple narrow beams will be used to compensate for the large propagation loss, and the SCS will be wider than that of the existing FR2 (e.g., 480 kHz, 960 kHz).

[0032] Figure 4 shows the relationship between SCS and symbol length (symbol time length). As shown in Figure 4, the symbol length (symbol time length) becomes shorter as the SCS becomes wider. Also, if the number of symbols per slot is constant (i.e., 14 symbols), the slot length becomes shorter as the SCS becomes wider.

[0033] In this way, when the beams become narrow and numerous and the SCS becomes wide, if the terminal 20 and the base station 10 operate according to the conventional regulations, there is a possibility that failure detection and recovery of the wireless link / beam cannot be performed appropriately. For example, as described later, it is assumed that LBT failures occur frequently, in which case there is a possibility that measurement of the reference signal for failure detection and recovery of the wireless link / beam cannot be performed appropriately.

[0034] The following describes a technique for the terminal 20 and the base station 10 to appropriately detect and recover from a failure in a wireless link / beam.

[0035] (Basic operation) First, a basic operation example in the wireless communication system of this embodiment will be described with reference to Fig. 5. In this embodiment, an aperiodic CSI-RS is used in which transmission from base station 10 and reception (and measurement) at terminal 20 are performed by triggering DCI, so first, a basic operation example related to the aperiodic CSI-RS will be described.

[0036] In S100, the terminal 20 transmits capability information (UE capability) to the base station 10. Using this capability information, the base station 10 can determine, for example, information to transmit to the terminal 20 in S101 and S102 below.

[0037] In S101, the base station 10 transmits setting information to the terminal 20 by using an RRC message, and the terminal 20 receives the setting information. The setting information is, for example, setting information related to aperiodic CSI-RS as described later.

[0038] In S102, the base station 10 transmits a trigger to the terminal 20 by DCI, and the terminal 20 receives the trigger. The trigger is, for example, a trigger for the terminal 10 to measure aperiodic CSI-RS for RLM / BFR, as described later. Note that in this embodiment, "A / B" means A or B, or both A and B. Also, "BFR" means "BFD / new beam selection".

[0039] Upon receiving the DCI, after a prescribed time, in S103, the terminal 20 receives the aperiodic CSI-RS, and in S104, performs measurements, for example, for detecting and recovering failures in a wireless link / beam.

[0040] As an example of an operation using CSI-RS, RLM / RLF and BFR will be described. Here, the operation based on the existing techniques disclosed in Non-Patent Documents 1 to 5 and the like will be described.

[0041] (RLM / RLF) First, RLM / RLF will be described. When the terminal 20 (and the base station 10) performs Radio Link Monitoring (RLM) and detects Radio Link Failure (RLF), an RRC connection re-establishment or the like is executed.

[0042] In RLM, counter values ​​N310 and N311, which are thresholds for the number of times, and timers T310 and T311, etc. are used. These parameters are received by the terminal 20 from the base station 10 through RRC signaling.

[0043] N310 is a threshold for the number of consecutive out-of-sync indications, and when the number of consecutive out-of-sync indications reaches N310, a timer T310 is started.

[0044] T310 starts with the above trigger and stops when N311 consecutive in-sync indications are notified. When T310 expires, for example, RRC connection re-establishment is executed. T311 starts at the start of an RRC connection re-establishment procedure in cell reselection and stops when cell reselection is successful. When T311 expires, terminal 20 enters an RRC idle state.

[0045] An example of the RLM procedure in the terminal 20 will be described with reference to Fig. 6. In the terminal 20, when a lower layer (e.g., a physical layer functional unit) detects out-of-sync (deterioration of radio link quality), it notifies an upper layer (e.g., an RRC functional unit) of the out-of-sync indication.

[0046] When the terminal 20 detects that N310 consecutive out-of-sync indications have been notified from a lower layer to a higher layer, the terminal 20 starts timer T310. When the terminal 20 detects that N311 consecutive in-sync indications (radio link normal notification) have been notified from a lower layer to a higher layer while timer T310 is running, the terminal 20 stops T310. If T310 expires, the terminal 20 determines that an RLF has occurred and executes an RRC connection re-establishment procedure.

[0047] The above in-sync indication is information defined, for example, as follows:

[0048] "Upon request from higher layers, the UE provides to higher layers the periodic CSI-RS configuration indexes and / or SS / PBCH block indexes from the set q1~ and the corresponding radio link quality measurements that are larger than or equal to Qin" In other words, an in-sync indication occurs when a certain threshold Q in The index of the P-CSI-RS from which the above wireless quality measurement values ​​were obtained, or (and) the index of the SS / PBCH block (hereinafter, may be referred to as SSB). The index of the target P-CSI-RS and the index of the SSB are within the set of "q1~". q1~ are parameters notified by RRC signaling from base station 10 to terminal 20 by candidateBeamRSList for wireless link quality measurement, for example. The wireless link quality may be RSRP or RSRQ.

[0049] The above out-of-sync indication is defined, for example, as follows:

[0050] "PHY in the UE provides an indication to higher layers when the radio link quality for all corresponding resource configurations in the set q0~ that the UE uses to assess the radio link quality is worse than the threshold Qout" That is, the out-of-sync indication is generated when the wireless link quality of all resources in the set “q0~” that the terminal 20 uses for wireless link quality evaluation is below a certain threshold Qout q0~ is a set of P-CSI-RS indexes notified by, for example, failureDetectionResources from base station 10 to terminal 20 through RRC signaling.

[0051] (BFD / BFR) Next, BFD / BFR will be explained. Here, a technique for detecting a beam failure (BFD) and recovering the beam (BFR) will be explained. First, a basic operation example of BFD / BFR in this embodiment will be explained with reference to Figs. 7 and 8.

[0052] First, an example of the BFD / BFR operation in the PCell / PSCell (BFR of R-15) will be described with reference to FIG.

[0053] In S10, the terminal 20 receives a reference signal (CSI-RS, SSB, or both CSI-RS and SSB) transmitted for each beam from the base station 10, and measures its quality (RSRP, RSRQ, etc.). Here, when the number of times that the terminal 20 has determined that the quality of all reference signals (i.e., beams) has deteriorated reaches a predetermined number of times, the terminal 20 searches for a new beam in S11.

[0054] All reference signals in S10 are a set of (indexes of) reference signals (failure detection resources) set from base station 10 to terminal 20 for measuring beam failure detection, and are called q0. For example, 8 is set to this.

[0055] In S11, the terminal 20 measures the L1-RSRP of candidate reference signals (candidateBeamRSList set by the base station 10, referred to as q1), and selects the reference signal (beam) with the maximum L1-RSRP as a new beam.

[0056] In S12, the terminal 12 transmits a PRACH (preamble) in a PRACH occasion corresponding to the newly selected beam. The terminal 20 monitors a BFR response (PDCCH) in a BFR response window starting four slots later.

[0057] Terminal 20, 28 symbols after receiving the BFR response (PDCCH) in S13, assumes that the PDCCH monitored in CORESET#0 has a QCL relationship with a new beam (reference signal), and monitors the PDCCH in CORESET#0.

[0058] Next, an example of the BFD / BFR operation for the SCell (BFR introduced in R-16) will be described with reference to Fig. 8. In Fig. 8, it is assumed that the SCell is provided by the base station 30.

[0059] In S21, the terminal 20 receives a reference signal (CSI-RS, SSB, or both CSI-RS and SSB) transmitted for each beam from the base station 30, and measures its quality (RSRP, RSRQ, etc.). Here, when the number of times that the quality of all reference signals (i.e., beams) is determined to have deteriorated reaches a predetermined threshold, the terminal 20 transmits an SR (scheduling request) in S21. In addition, in S23, a search for a new beam is performed.

[0060] All reference signals in S20 are a set of (indexes of) reference signals set from the base station 10 to the terminal 20 for measuring beam failure detection, and are referred to as failure detection resources, q0. For example, 8 is set to this.

[0061] In S23, the terminal 20 measures the L1-RSRP of candidate reference signals (candidateBeamRSList set by the base station 10, referred to as q1), and selects the reference signal (beam) with the maximum L1-RSRP as a new beam.

[0062] In S22, the terminal 20 receives the UL-grant, and transmits the MAC CE in S24 using the allocated resources. The MAC CE includes the index of the CC in which the beam failure occurred and the index of the new reference signal for each CC (i.e., the index of the beam). The terminal 20 receives the BFR response (PDCCH) in S25.

[0063] The terminal 20 monitors the PDCCH 28 symbols after receiving the PDCCH (PDCCH of S25) that schedules the PUSCH, assuming that the PDCCH monitored on the SCell thereafter has a QCL relationship with the new beam (reference signal). Furthermore, the terminal 20 transmits the PUSCH transmitted on the SCell 28 symbols after that using a spatial domain filter corresponding to the spatial domain filter of the new beam (reference signal). That is, the QCL is also updated for the PUSCH.

[0064] (About setting information for reference signals, etc.) FIG. 9 shows an example of configuration information related to RLM / BFD (Non-Patent Document 2). As shown in FIG. 9, the purpose, resources, etc. of the reference signal can be set by RadioLinkMonitoringRS. FIG. 10 shows an example of configuration information related to BFR (Non-Patent Document 2). (Use of non-periodic reference signals) The frequency band of 52.6 to 71 GHz that is expected to be used in the wireless communication system of this embodiment includes unlicensed spectrum (unlicensed band), so the wireless communication system of this embodiment may require LBT.

[0065] In the RLM and BFR based on the above-mentioned existing technology, the terminal 20 receives a reference signal (CSI-RS, SSB, or CSI-RS and SSB) periodically transmitted from the base station 10 and measures the quality.

[0066] However, when LBT is performed in base station 10, for example, as shown in Fig. 11, LBT may or may not be successful at each transmission timing of the reference signal. Therefore, it is expected that base station 10 will not be able to transmit the reference signal periodically, and the frequency with which terminal 20 can receive the reference signal will decrease. Therefore, there is a possibility that RLM and BFR cannot be executed appropriately.

[0067] In order to solve the above problem, a non-periodic reference signal based on a DCI trigger is used instead of a periodic reference signal as a reference signal used by the terminal 20 for beam monitoring / selection in RLM or BFR. The non-periodic reference signal is, for example, an aperiodic CSI-RS.

[0068] For example, when the terminal 20 and the base station 10 use an unlicensed band (or perform LBT), the base station 10 transmits a reference signal at the timing when the LBT is successful.

[0069] The terminal 20 executes RLM and BFR by measuring a reference signal received non-periodically based on a trigger, for example, by performing counting processes and the like described in Figures 6, 7, 8, etc. This allows the terminal 20 to appropriately execute RLF and BFR without being affected by LBT failure when LBT is required. Note that the technology according to the present invention can also be applied even when LBT is not assumed.

[0070] (Aperiodic CSI report triggering) Here, configuration information and the like of aperiodic CSI report triggering based on existing techniques (Non-Patent Documents 2, 5, etc.) will be described with reference to FIG.

[0071] In order to implement the Aperiodic CSI report triggering, first, a CSI-AperiodicTriggerStateList is configured by RRC from the base station 10 to the terminal 20. The CSI-AperiodicTriggerStateList includes one or more indexed CSI-AperiodicTriggerStates.

[0072] After that, one CSI-AperiodicTriggerState in the CSI-AperiodicTriggerStateList is specified by the CSI request field of the DCI transmitted from the base station 10 to the terminal 20. Note that the number of bits in the CSI request field (N TS ) is shorter than the length required to specify all configured CSI-AperiodicTriggerStates, then the MAC CE is also used.

[0073] One CSI-AperiodicTriggerState is associated with one or more Report settings, and a Report setting is associated with one or more Resource settings. One Resource setting includes one or more CSI-RS resource sets. One CSI-RS resource set includes one or more CSI-RS resources. That is, terminal 20 can receive CSI-RS using one or more CSI-RS resources associated with the CSI-AperiodicTriggerState specified by the CSI request field.

[0074] Fig. 13 shows an example of CSI-AperiodicTriggerStateList (Non-Patent Document 2). As shown in Fig. 13, CSI-AperiodicTriggerStateList includes one or more CSI-AperiodicTriggerStates, and CSI-AperiodicTriggerStates includes one or more resourceSets. The resourceSet indicates an NZP-CSI-RS-ResourceSet for channel measurement.

[0075] (For detailed assignments) When applying aperiodic CSI-RS to RLM / BFR in order to properly execute RLM / BFR even in a situation where an LBT failure occurs, issues arise as to whether to apply periodic CSI-RS / SSB to RLM / BFR and how to trigger aperiodic CSI-RS for RLM / BFR.

[0076] That is, if the existing aperiodic CSI report triggering is applied as is, the triggered CSI-RS will be used for CSI / beam reporting or tracking depending on ReportQuantity. Therefore, in order to support the aperiodic CSI-RS for RLM / BFR, it is necessary to notify terminal 20 of the purpose (CSI / beam reporting, tracking, or RLM / BFR) for which the triggered aperiodic CSI-RS will be used.

[0077] For this purpose, this embodiment proposes an extension of the trigger DCI and an extension of the RRC configuration, which will be described in detail later.

[0078] As a method for supporting an aperiodic CSI-RS trigger for RLM / BFR, the following Alt1 and Alt2 are conceivable. In this embodiment, however, Alt1 is adopted in consideration of the impact on the specifications.

[0079] Alt1: Reuse the R-16 aperiodic CSI report triggering procedure as a baseline and extend it.

[0080] Atl2: Design a new procedure to support aperiodic CSI-RS triggering for RLM / BFR.

[0081] Specific examples of the present embodiment will be described below as Examples 1 to 4 and modifications. Any or all of Examples 1 to 4 can be implemented in combination.

[0082] Example 1 Example 1 is an example from the viewpoint of whether to use only the Aperiodic CSI-RS or to use the Periodic CSI-RS together with the Aperiodic CSI-RS for measurement in RLM / BFR. Hereinafter, Examples 1-1, 1-2, and 1-3 will be described.

[0083] <Example 1-1> In Example 1-1, only the aperiodic CSI-RS is used for measurements in RLM / BFR. In this case, there are the following variations of Alt1 and Alt2 for the selection of beams to be applied to the aperiodic CSI-RS.

[0084] Alt1: The Aperiodic CSI-RS beam used shall be the same as the beam set in CORESET.

[0085] In this case, for example, information indicating the same beam as the beam set in CORESET is set from base station 10 to terminal 20 as setting information (for example, TCI state) related to the beam of the Aperiodic CSI-RS.

[0086] Alt2: No restrictions are placed on the Aperiodic CSI-RS beams used.

[0087] <Example 1-2> In the embodiment 1-2, both the aperiodic CSI-RS and the periodic CSI-RS / SSB can be used for RLM / BFR. That is, the existing periodic CSI-RS / SSB can be used for RLM / BFR in addition to being used for existing purposes such as CSI / beam reporting, and further, the aperiodic CSI-RS can be used for RLM / BFR.

[0088] There are the following Alt1 and Alt2 variations for the selection of beams to be applied to the aperiodic CSI-RS in Example 1-2.

[0089] Alt1: The beam of the Aperiodic CSI-RS used in RLM / BFR is the same as the beam set for the Periodic CSI-RS also used in RLM / BFR. This case assumes that the Aperiodic CSI-RS is used as a backup during periods when the Periodic CSI-RS is not transmitted.

[0090] In this case, for example, information indicating the same beam as the beam set in the Periodic CSI-RS is set from the base station 10 to the terminal 20 as setting information (for example, TCI state) related to the beam of the Aperiodic CSI-RS.

[0091] Alt2: The Aperiodic CSI-RS beam used in RLM / BFR shall be the same as the beam set in CORESET.

[0092] In addition, the beam of the Aperiodic CSI-RS may be the same as or different from the beam of the Periodic CSI-RS configured for BFD. Also, more PDCCH beams may be assumed in BFD.

[0093] Alt3: No restrictions are placed on the beams of the Aperiodic CSI-RS used in RLM / BFR.

[0094] <Example 1-3> In the first to third embodiments, whether to use Aperiodic CSI-RS or Periodic CSI-RS for RLM / BFR is selected based on conditions.

[0095] For example, when LBT is required for signal transmission, the base station 10 determines to use aperiodic CSI-RS for RLM / BFR, and performs operations to cause the terminal 20 to use aperiodic CSI-RS for RLM / BFR (based on DCI or RRC settings described below).

[0096] In addition, when using a carrier in a specific band (e.g., an unlicensed band), the base station 10 may determine to use the aperiodic CSI-RS for RLM / BFR, and perform an operation to cause the terminal 20 to use the aperiodic CSI-RS for RLM / BFR.

[0097] The same embodiment (embodiment 1-1, embodiment 1-2, or embodiment 1-3) may be applied to the RLM and the BFR, or different embodiments may be applied to the RLM and the BFR.

[0098] Example 2 Next, a description will be given of a second embodiment. In the second embodiment, a DCI that is an extension of an existing DCI is used to trigger an aperiodic CSI-RS for RLM / BFD.

[0099] An operation example of the second embodiment will be described with reference to Fig. 5 mentioned above. In S101, setting information related to the Aperiodic CSI-RS is transmitted from the base station 10 to the terminal 20 by an RRC message. The setting information here may be, for example, existing information disclosed in Non-Patent Document 2 (such as CSI-AperiodicTriggerStateList shown in Fig. 11).

[0100] In S102, a trigger for the aperiodic CSI-RS (a measurement trigger for the terminal 20) is transmitted from the base station 10 to the terminal 20 by the extended DCI in the second embodiment. This DCI includes information instructing the terminal 20 to use the aperiodic CSI-RS for the purpose of RLM / BFD.

[0101] The terminal 20 receives the aperiodic CSI-RS a certain time after receiving the DCI, and performs measurement (S103, S104). This measurement is performed for RLM / BFD. From the viewpoint of the base station 10, the DCI transmission is used as a trigger to transmit the aperiodic CSI-RS a certain time later.

[0102] More specific examples will be described below as Examples 2-1, 2-2, and 2-3. Any two or all of Examples 2-1, 2-2, and 2-3 may be combined and carried out.

[0103] <Example 2-1> In the embodiment 2-1, the DCI field is extended (such as by adding a new field). As the DCI format and the RNTI for scrambling the DCI, an existing format (e.g., DCI format 0_1, DCI format 0_2) and an existing RNTI may be used.

[0104] In addition, instead of extending the DCI field, an interpretation (reinterpretation) different from the existing interpretation may be applied to the (value of) the existing DCI field to realize an aperiodic CSI-RS trigger for RLM / BFD.

[0105] As an extension of the DCI field, for example, a purpose indication field may be provided, and the purpose of the trigger may be indicated by the purpose indication field (its value).

[0106] A plurality of purposes (purpose sets) that can be indicated by the purpose indication field may be defined in a specification, or may be set by the base station 10 to the terminal 20 by the RRC. The purpose set may be one or more of the following purposes 1 to 7.

[0107] purpose 1: Trigger for an existing purpose (e.g. beam / CSI reporting, tracking) Purpose 2: Trigger for RLM measurement Purpose 3: Trigger for BFD measurement purpose 4: Triggering for both RLM and BFD measurements purpose 5: triggering for RLM or BFD measurements or both RLM and BFD measurements purpose 6:purpose 1+purpose 2 / 3 / 4 purpose 7:purpose 1+purpose 5 For purpose 5 among the above-mentioned purposes 1 to 7, the terminal 20 that has received the DCI may refer to the RRC configuration in order to identify the purpose (RLM, BFD, or both). In addition, purposes 6 and 7 indicate that they can be used for both the existing purpose and the purpose of RLM / BFD.

[0108] <Example 2-2> In the embodiment 2-2, a new DCI format for triggering the aperiodic CSI-RS for RLM / BFD is used. When the new DCI format is used, the new field in the embodiment 2-1 may or may not be included.

[0109] When a terminal 20 receives a DCI of a new DCI format from a base station 10, the terminal 20 detects the new DCI format and determines that the DCI is a DCI for triggering an aperiodic CSI-RS for RLM / BFD, and uses the CSI-RS specified in the DCI for measurements for RLM / BFD.

[0110] <Example 2-3> In Example 2-3, the base station 10 scrambles an existing DCI format with a new RNTI (e.g., RLM-BFR-CSI-RNTI) and transmits the scrambled DCI format in order to trigger an aperiodic CSI-RS for RLM / BFD.

[0111] Since terminal 20 is able to decode the DCI using the new RNTI, it determines that the DCI is a DCI for triggering an aperiodic CSI-RS for RLM / BFD, and uses the CSI-RS specified in the DCI for measurements for RLM / BFD.

[0112] <Other examples (variations)> The DCI in each of the embodiments 2-1, 2-2, and 2-3 may be UE-specific, group common, or common within a cell.

[0113] In addition, in both of Examples 2-2 and 2-3, the purpose indication field in Example 2-1 may or may not be included. When the purpose indication field is included in the DCI in Examples 2-2 and 2-3, the purpose set may be any one or more or all of purposes 2 to 7.

[0114] <Effects of Example 2> The terminal 20 that has received the DCI of the second embodiment can determine whether the aperiodic CSI-RS triggered by the DCI is to be used for CSI / beam reporting or RLM / BFD. In addition, since the purpose of the trigger can be accurately determined by the DCI, the terminal 20 can use the existing procedure (Rel-16 A-CSI report triggering procedure) and the existing RRC setting information.

[0115] Example 3 Next, a description will be given of a third embodiment. In the third embodiment, in order to realize a trigger of an aperiodic CSI-RS for RLM / BFD, RRC configuration information that is an extension of existing RRC configuration information is used.

[0116] An operation example of the third embodiment will be described with reference to Fig. 5. In S101, setting information related to the aperiodic CSI-RS is transmitted from the base station 10 to the terminal 20 by an RRC message. The setting information here is an extension (or modification) of the existing setting information disclosed in, for example, Non-Patent Document 2.

[0117] In S102, for example, a trigger for aperiodic CSI-RS (a measurement trigger for terminal 20) is transmitted from base station 10 to terminal 20 by existing DCI. This DCI includes the CSI request field described in FIG.

[0118] A certain CSI-AperiodicTriggerState is specified by the CSI request field.

[0119] In the third embodiment, the CSI-AperiodicTriggerState specified by the CSI request field is associated with the configuration information of the aperiodic CSI-RS for RLM / BFD. Therefore, the terminal 20 can receive the aperiodic CSI-RS based on the configuration information of the aperiodic CSI-RS and perform measurements for RLM / BFD (S103, S104).

[0120] More specific examples will be described below as Examples 3-1, 3-2, 3-3, and 3-4. Any two, three, or all of Examples 3-1, 3-2, 3-3, and 3-4 may be combined and carried out.

[0121] <Example 3-1> Conventionally, only periodic measurements were possible for RLM and BFD measurements. Therefore, in Example 3-1, it is possible to set aperiodic for CSI-RS for RLM and BFD.

[0122] That is, in Example 3-1, configuration information of the reference signal for RLM and BFD includes configuration information of the aperiodic CSI-RS. When the terminal 20 detects that the aperiodic CSI-RS associated with the CSI-AperiodicTriggerState specified by the CSI request field is configured for RLM / BFD, it uses the aperiodic CSI-RS to perform measurement in RLM / BFD. Note that there are the following variations Alt1 and Alt2 regarding the use of the aperiodic CSI-RS configured for RLM / BFD.

[0123] Alt1: The aperiodic CSI-RS for RLM / BFD associated with CSI-AperiodicTriggerState may also be used for existing purposes (e.g., CSI / beam reporting).

[0124] Alt2: Whether the aperiodic CSI-RS for RLM / BFD linked to CSI-AperiodicTriggerState may also be used for existing purposes (CSI / beam reporting, etc.) may be specified by an RRC parameter in the configuration information of the aperiodic CSI-RS.

[0125] <Specific example of Example 3-1> A specific example of the setting information in the embodiment 3-1 will be described.

[0126] For example, a new IE parameter (e.g., RadioLinkMonitoringRS-r17) is used as the configuration information of the Aperiodic CSI-RS resource for RLM / BFD. That is, the base station 10 transmits configuration information having the new IE parameter (e.g., RadioLinkMonitoringRS-r17) to the terminal 20 as the configuration information of the Aperiodic CSI-RS resource for RLM / BFD.

[0127] RadioLinkMonitoringRS-r17 is set as configuration information of the aperiodic CSI-RS for RLM / BFD associated with CSI-AperiodicTriggerState. This allows the terminal 20 triggered by DCI to perform measurement for RLM / BFD using the aperiodic CSI-RS associated with the specified CSI-AperiodicTriggerState and set by RadioLinkMonitoringRS-r17.

[0128] When the above Alt1 is applied, the aperiodic CSI-RS for RLM / BFD associated with CSI-AperiodicTriggerState can be used for existing purposes.When the above Alt2 is applied, RadioLinkMonitoringRS-r17 sets whether the aperiodic CSI-RS for RLM / BFD associated with CSI-AperiodicTriggerState can be used for existing purposes.

[0129] An example of RadioLinkMonitoringRS-r17 assuming Alt2 is shown in Fig. 14. The purpose shown in Fig. 14 allows you to specify whether the purpose of the aperiodic CSI-RS set in RadioLinkMonitoringRS-r17 is RLM (rlf in Fig. 14), BFR (beamFailure in Fig. 14), or both.

[0130] <Example 3-2> In Example 3-2, as the setting information of CSI-AperiodicTriggerState, setting information extended from the existing setting information disclosed in Non-Patent Document 2 is used. Fig. 15 shows CSI-AperiodicTriggerState-r17 which is an example of the setting information of CSI-AperiodicTriggerState in Example 3-2.

[0131] As shown in Fig. 15, TriggeringPurpose is included. TriggeringPurpose indicates the purpose (use) of all aperiodic CSI-RS linked to this CSI-AperiodicTriggerState-r17. As TriggeringPurpose, RLM / BFD, existing purpose (CSI / beam reporting), etc. can be set. The example of Fig. 15 shows that a subset of purposes 1 to 7 described in the second embodiment can be set.

[0132] Assume that terminal 20 in which configuration information including the above-mentioned CSI-AperiodicTriggerState-r17 is set has a specific CSI-AperiodicTriggerState-r17 specified by the CSI request field of DCI.

[0133] For example, when the terminal 20 determines that the purpose is RLM / BFD from the TriggeringPurpose in the CSI-AperiodicTriggerState-r17, it uses the aperiodic CSI-RS linked to the CSI-AperiodicTriggerState-r17 for measuring RLM / BFD.

[0134] Also, for example, when terminal 20 determines from TriggeringPurpose in CSI-AperiodicTriggerState-r17 that the purpose is both RLM and CSI reporting, it uses the aperiodic CSI-RS linked to CSI-AperiodicTriggerState-r17 for RLM measurement and also for CSI reporting.

[0135] <Effects of Example 3-2> In Example 3-2, aperiodical CSI-RS for RLM / BFD can be realized while utilizing the existing (Rel-16) aperiodical CSI-RS report triggering procedure as is.

[0136] <Example 3-3> Next, Example 3-3 will be described. In Example 3-3, similarly to Example 3-2, the setting information of CSI-AperiodicTriggerState is extended. More specifically, in Example 3-3, setting information extended from the existing setting information disclosed in Non-Patent Document 2 is used as the setting information of reporting settings in CSI-AperiodicTriggerState.

[0137] FIG. 16 shows CSI-AperiodicTriggerState-r17, which is an example of CSI-AperiodicTriggerState in Example 3-3.

[0138] As shown in Fig. 16, TriggeringPurpose can be set for each CSI-AssociatedReportConfigInfo in associatedReportConfigInfoList. TriggeringPurpose indicates the purpose (use) of the aperiodic CSI-RS associated with the corresponding CSI-AssociatedReportConfigInfo. As TriggeringPurpose, RLM / BFD, an existing purpose (CSI / beam report), etc. can be set. The example of Fig. 16 shows that a subset of purposes 1 to 7 described in the second embodiment can be set.

[0139] Assume that terminal 20 in which configuration information including the above-mentioned CSI-AperiodicTriggerState-r17 is set has a specific CSI-AperiodicTriggerState-r17 specified by the CSI request field of DCI.

[0140] For example, when the terminal 20 determines that the purpose is RLM / BFD from the TriggeringPurpose of a CSI-AssociatedReportConfigInfo in the CSI-AperiodicTriggerState-r17, it uses the aperiodic CSI-RS associated with the CSI-AssociatedReportConfigInfo for measuring RLM / BFD.

[0141] For example, when terminal 20 determines from the TriggeringPurpose of a CSI-AssociatedReportConfigInfo in the CSI-AperiodicTriggerState-r17 that the purpose is both RLM and CSI reporting, it uses the aperiodic CSI-RS linked to the CSI-AssociatedReportConfigInfo for RLM measurement and also for CSI reporting measurement.

[0142] <Effects of Example 3-3> In Example 3-3, aperiodical CSI-RS for RLM / BFD can be realized while utilizing the existing (Rel-16) aperiodical CSI-RS report triggering procedure as is.

[0143] In addition, in Example 3-3, a purpose can be set for each of a plurality of different report settings in one CSI-AperiodicTriggerState. Therefore, for each of a plurality of different report settings in one CSI-AperiodicTriggerState, the associated aperiodic CSI-RS can be used for the respective purpose.

[0144] On the other hand, in Example 3-2, one purpose is set for one CSI-AperiodicTriggerState. That is, the same purpose is set for all reporting settings included in one CSI-AperiodicTriggerState. Therefore, all aperiodic CSI-RSs associated with different report settings in one CSI-AperiodicTriggerState are used for the same purpose.

[0145] <Example 3-4> Next, an example 3-4 will be described. In the example 3-4, the configuration information is extended so that the CSI-AperiodicTriggerStateList includes a TriggerState for RLM / BFD. Also, a new structure is used as the structure of the TriggerState.

[0146] As an example of the CSI-AperiodicTriggerStateList used in Example 3-4, Alt1 and Alt2 will be described.

[0147] Alt1: In Alt1, a CSI-AperiodicTriggerStateList including only a new CSI-AperiodicTriggerState for RLM / BFD is used. Figure 17 shows an example of the CSI-AperiodicTriggerStateList of Alt1. As shown in Figure 17, the CSI-AperiodicTriggerStateList of Alt1 includes only CSI-AperiodicTriggerStateRlm-r17, which is a new CSI-AperiodicTriggerState for RLM / BFD.

[0148] In Alt1, for example, terminal 20 determines whether to use an existing CSI-AperiodicTriggerStateList or a new CSI-AperiodicTriggerStateList based on DCI received as a trigger for aperiodic CSI-RS. For example, DCI may include instruction information indicating whether to use an existing CSI-AperiodicTriggerStateList or a new CSI-AperiodicTriggerStateList, and terminal 20 may make the determination based on the instruction information.

[0149] In addition, for example, the interpretation of the value of the CSI request field of DCI may be different from the conventional interpretation, so that, for example, if the value of the CSI request field of DCI is equal to or greater than a certain value, it indicates that a new CSI-AperiodicTriggerStateList is to be used, and if not, it indicates that the existing CSI-AperiodicTriggerStateList is to be used.

[0150] In Alt2:Alt12, a CSI-AperiodicTriggerStateList is used, which includes a CSI-AperiodicTriggerState for an existing purpose (CSI reporting, etc.) and a new CSI-AperiodicTriggerState for RLM / BFD. An example of the CSI-AperiodicTriggerStateList of Alt2 is shown in Figure 18. As shown in Figure 18, the CSI-AperiodicTriggerStateList of Alt1 includes the existing CSI-AperiodicTriggerState and CSI-AperiodicTriggerStateRlm-r17, which is a new CSI-AperiodicTriggerState for RLM / BFD.

[0151] An existing DCI can be used as the trigger DCI in Alt2. The terminal 20 uses the existing CSI-AperiodicTriggerState or CSI-AperiodicTriggerStateRlm-r17 in accordance with the CSI request field of the DCI received from the base station 10.

[0152] <About CSI-AperiodicTriggerState in Example 3-4> The new CSI-AperiodicTriggerState for RLM / BFD in the embodiment 3-4 may include a list of aperiodic CSI-RS resources for RLM / BFD without including information related to reporting. Below, examples 1 and 2 are shown as examples of the structure of CSI-AperiodicTriggerStateRlm-r17, which is the new CSI-AperiodicTriggerState for RLM / BFD.

[0153] Example 1: Figure 19 shows CSI-AperiodicTriggerStateRlm-r17 in Example 1. In Example 1, each CSI-AperiodicTriggerStateRlm-r17 is associated with a list of aperiodic CSI-RS resources for RLM / BFD.

[0154] In the example of Fig. 19, RadioLinkMonitoringRS-r17 corresponds to the list. This Example 1 is also an example in Example 3-1. As RadioLinkMonitoringRS-r17 shown in Fig. 19, for example, the one shown in Fig. 14 in Example 3-1 can be used.

[0155] Example 2: Figure 20 shows CSI-AperiodicTriggerStateRlm-r17 in Example 2. In Example 2, each CSI-AperiodicTriggerStateRlm-r17 is associated with a list of aperiodic CSI-RS resources for RLM / BFD.

[0156] In the example of Figure 20, the list corresponds to the one indicated by NZP-CSI-RS-ResourceId. The purpose of the aperiodic CSI-RS resource for RLM / BFD can be set commonly to a set of aperiodic CSI-RS resource lists (using PurposeCommon) or can be set individually to each aperiodic CSI-RS resource list (using PurposeSeparate).

[0157] <Effects of Examples 3-4> According to Example 3-4, separate CSI-AperiodicTriggerStates can be used for RLM / BFD and for existing purposes (CSI reporting, etc.).

[0158] Example 4 Next, a fourth embodiment will be described. The fourth embodiment is an embodiment regarding new beam selection in BFR. That is, the fourth embodiment is an embodiment that enables the terminal 20 to perform measurement by aperiodic CSI-RS for the purpose of selecting a new beam in BFR.

[0159] In order to enable the terminal 20 to perform measurements using aperiodic CSI-RS for the purpose of selecting a new beam in BFR, the techniques described in the second and third embodiments can be applied. That is, in the contents described in the second and third embodiments, "RLM / BFD" is replaced with "selection of a new beam" to obtain the fourth embodiment. More specifically, the fourth embodiment is as shown in the following examples 4-1 and 4-2.

[0160] <Example 4-1> Example 4-1 corresponds to Example 2. That is, the extension of DCI enables the terminal 20 to perform measurement by aperiodic CSI-RS for the purpose of selecting a new beam in BFR. Example 4-1 is obtained by replacing "RLM / BFD" in Example 2 with "selection of new beam".

[0161] <Example 4-2> Example 4-2 corresponds to Example 3. That is, by extending the RRC setting information, the terminal 20 is enabled to perform measurement by the aperiodic CSI-RS for the purpose of selecting a new beam in BFR. Basically, Example 4-2 is obtained by replacing "RLM / BFD" in Example 3 with "new beam selection".

[0162] As a more specific example, an example of configuration information used in Example 4-2 for Example 3-1 is shown in Fig. 21. As shown in Fig. 21, candidateBeamRSList-r17, which is a list of beams detected by measuring Aperiodic CSI-RS, is configured. The resource of each Aperiodic CSI-RS in candidateBeamRSList-r17 is configured by PRACH-A-CSI-ResourceDedicatedBFR-r1.

[0163] In Example 4-2 compared to Example 3-1, the terminal 20 detects a new beam by measuring the aperiodic CSI-RS specified in candidateBeamRSList-r17 linked to the triggering state specified in the DCI.

[0164] With respect to Examples 3-2 to 3-4, Example 4-2 is obtained by replacing the purpose "RLM / BFD" with "new beam selection" in Examples 3-2 to 3-4. In addition, a correspondence relationship between aperiodic CSI-RS resources that can be used in new beam selection and PRACH resources may be set.

[0165] (Modification) Next, a modified example that can be applied to any of the first to fourth embodiments will be described.

[0166] <Variation 1> A relationship may be defined between a beam of an aperiodic CSI-RS triggered for RLM / BFR and a beam used during LBT sensing. The relationship may be specified in a specification, or may be set in the terminal 20 by the base station 10. Examples of the relationship include the following examples 1 to 3.

[0167] Example 1: The beam of the Aperiodic CSI-RS triggered for RLM / BFR and the beam used for LBT sensing are assumed to have the same direction and width (thickness).

[0168] Example 2: The beam of the Aperiodic CSI-RS triggered for RLM / BFR and the beam used for LBT sensing have the same direction but different widths. For example, the beam width of the Aperiodic CSI-RS is narrower than the beam width used for LBT sensing.

[0169] Example 3: The beam of the Aperiodic CSI-RS triggered for RLM / BFR and the beam used for LBT sensing have different directions and widths. For example, the space defined by the direction and width of the Aperiodic CSI-RS beam is included in the space defined by the direction and width of the beam used for LBT sensing corresponding to COT.

[0170] <Variation 2> Each of the first to fourth embodiments may be applied to a case where a frequency in a specific frequency range is used in the base station 10 and the terminal 20. The specific frequency range may be 52.6 to 71 GHz.

[0171] <Modification 3> Each of the first to fourth embodiments may be applied when a specific condition is satisfied. For example, whether or not the operation of using the aperiodic CSI-RS for RLM / BFR can be performed may be determined based on whether the LBT operation is ON or OFF, or whether the band to be used is an unlicensed band or a licensed band.

[0172] For example, when LBT operation is ON (or the band used is an unlicensed band), the base station 10 may transmit the DCI described in the second embodiment to cause the terminal 20 to use the aperiodic CSI-RS for RLM / BFR.

[0173] In addition, when LBT operation is ON (or the band to be used is an unlicensed band), the base station 10 may perform the RRC configuration described in the third embodiment to cause the terminal 20 to use the aperiodic CSI-RS for RLM / BFR.

[0174] <Variation 4> The second embodiment (DCI extension) and the third embodiment (RRC extension) may be combined and implemented. The same applies to the fourth embodiment, which corresponds to the second embodiment (DCI extension) and the third embodiment (RRC extension).

[0175] <Variation 5> Regarding each of the examples described in the first to fourth embodiments, whether the terminal 20 uses it or not may be set / instructed / reported according to the following first to fourth embodiments.

[0176] Example 1: Setting is performed on the terminal 20 using higher layer parameters (eg, RRC, MAC CE).

[0177] Example 2: The terminal 20 reports UE capability to the base station 10.

[0178] Example 3: Specified in the specification.

[0179] Example 4: Determined based on the settings made by higher layer parameters and the reported UE capability (a combination of examples 1 and 2).

[0180] <Variation 6> Modification 6 is an example regarding UE capability. The UE capabilities shown in the following examples 1 to 8 may be defined, and any of the UE capabilities may be reported from the terminal 20 to the base station 10. This operation corresponds to the operation of S100 in FIG.

[0181] Example 1: UE capability indicating whether the terminal 20 supports aperiodic CSI-RS for RLM / BFR.

[0182] Example 2: UE capability indicating whether the terminal 20 supports only Aperiodic CSI-RS for RLM / BFR.

[0183] Example 3: UE capability indicating whether the terminal 20 supports Periodic CSI-RS in addition to Aperiodic CSI-RS for RLM / BFR.

[0184] Example 4: UE capability indicating whether the terminal 20 supports a new DCI format that triggers aperiodic CSI-RS for RLM / BFR.

[0185] Example 5: UE capability indicating whether the terminal 20 supports an existing DCI format using a new RNTI that triggers an aperiodic CSI-RS for RLM / BFR.

[0186] Example 6: UE capability indicating whether the terminal 20 supports an existing DCI format using an existing RNTI that triggers an aperiodic CSI-RS for RLM / BFR.

[0187] Example 7: UE capability indicating whether the terminal 20 supports Aperiodic CSI-RS for RLM / BFR measurement purposes in addition to existing purposes (e.g., beam / CSI reporting, tracking).

[0188] Example 8: UE capability indicating whether or not the terminal 20 supports RRC configuration information for determining for what purpose the Aperiodic CSI-RS is used.

[0189] The technique according to the present embodiment described above provides a technique that enables a terminal to appropriately perform failure detection and recovery in a wireless communication system.

[0190] (Device configuration) Next, a description will be given of an example of the functional configuration of the base station 10 and the terminal 20 that execute the processes and operations described above.

[0191] <Base station 10> Fig. 22 is a diagram showing an example of the functional configuration of the base station 10. As shown in Fig. 22, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Fig. 22 is merely an example. As long as the operation related to the embodiment of the present invention can be executed, the functional divisions and the names of the functional units may be any. Furthermore, the transmitting unit 110 and the receiving unit 120 may be collectively referred to as a communication unit.

[0192] The transmitter 110 has a function of generating a signal to be transmitted to the terminal 20 and transmitting the signal wirelessly. The receiver 120 has a function of receiving various signals transmitted from the terminal 20 and acquiring, for example, information of a higher layer from the received signals. The transmitter 110 also has a function of transmitting, to the terminal 20, NR-PSS, NR-SSS, NR-PBCH, DL / UL control signals, DCI by PDCCH, data by PDSCH, and the like.

[0193] The setting unit 130 stores preset setting information and various setting information to be transmitted to the terminal 20 in a storage device provided in the setting unit 130, and reads out the information from the storage device as necessary.

[0194] The control unit 140 schedules DL reception or UL transmission of the terminal 20 via the transmission unit 110. The control unit 140 also includes a function for performing LBT. A functional unit related to signal transmission in the control unit 140 may be included in the transmission unit 110, and a functional unit related to signal reception in the control unit 140 may be included in the reception unit 120. The transmission unit 110 may be called a transmitter, and the reception unit 120 may be called a receiver.

[0195] <Terminal 20> Fig. 23 is a diagram showing an example of the functional configuration of the terminal 20. As shown in Fig. 23, the terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Fig. 12 is merely an example. As long as the operation related to the embodiment of the present invention can be executed, the names of the functional divisions and functional units may be any. The transmitting unit 210 and the receiving unit 220 may be collectively referred to as a communication unit.

[0196] The transmitter 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiver 220 wirelessly receives various signals and acquires a higher layer signal from the received physical layer signal. The receiver 220 also has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, DCI by PDCCH, data by PDSCH, and the like transmitted from the base station 10. For example, the transmitter 210 may transmit a PSCCH (Physical Sidelink Control Channel), a PSSCH (Physical Sidelink Shared Channel), a PSDCH (Physical Sidelink Discovery Channel), a PSBCH (Physical Sidelink Broadcast Channel), and the like to another terminal 20 as D2D communication, and the receiver 120 may receive the PSCCH, the PSSCH, the PSDCH, or the PSBCH, and the like, from the other terminal 20.

[0197] The setting unit 230 stores various setting information received from the base station 10 or other terminals by the receiving unit 220 in a storage device provided in the setting unit 230, and reads it from the storage device as necessary. The setting unit 230 also stores setting information that is set in advance. The control unit 240 controls the terminal 20. The control unit 240 also includes a function of performing LBT.

[0198] The terminal and base station of this embodiment may be configured as the terminal and base station shown in the following items. Also, the following measurement method may be implemented.

[0199] <Configurations related to Examples 2 and 4> (Section 1) A receiving unit that receives downlink control information from a base station; a control unit that performs measurement for radio link monitoring or beam failure recovery using a non-periodic reference signal received from the base station based on a trigger by the downlink control information; A terminal comprising: (Section 2) The downlink control information includes a purpose of a non-periodic reference signal; The control unit determines, based on the purpose, that the non-periodic reference signal is a reference signal to be used for radio link monitoring or beam failure recovery. 2. The terminal described in paragraph 1. (Section 3) The control unit determines, based on a format of the downlink control information, that the non-periodic reference signal is a reference signal to be used for radio link monitoring or beam failure recovery. 3. A terminal as described in claim 1 or 2. (Section 4) The control unit determines, based on the RNTI used for scrambling the downlink control information, that the non-periodic reference signal is a reference signal to be used for radio link monitoring or beam failure recovery. A terminal according to any one of claims 1 to 3. (Section 5) A transmitter for transmitting downlink control information to a terminal, The transmitting unit transmits an aperiodic reference signal based on a trigger by the downlink control information, and the terminal performs measurement for radio link monitoring or beam failure recovery by the aperiodic reference signal. Base station. (Section 6) receiving downlink control information from a base station; performing measurement for radio link monitoring or beam failure recovery using a non-periodic reference signal received from the base station based on a trigger by the downlink control information; A measurement method in a terminal comprising:

[0200] Any of the above configurations provides a technique that enables a terminal to appropriately perform fault detection and recovery in a wireless communication system. According to the second paragraph, the purpose can be explicitly grasped. According to the third and fourth paragraphs, the purpose can be grasped by the terminal even if it is not explicitly included.

[0201] <Configurations related to Examples 3 and 4> (Section 1) A receiving unit that receives setting information of a non-periodic reference signal used for radio link monitoring or beam failure recovery from a base station; a control unit that performs measurement for radio link monitoring or beam failure recovery using the non-periodic reference signal based on a trigger by downlink control information received from the base station; A terminal comprising: (Section 2) A receiving unit that receives configuration information including a purpose of the non-periodic reference signal from a base station; a control unit that performs measurement for radio link monitoring or beam failure recovery using a non-periodic reference signal designated by the setting information according to the purpose, based on a trigger by downlink control information received from the base station; A terminal comprising: (Section 3) The purpose is included in each triggering state in the setting information. 3. A terminal as described in paragraph 2. (Section 4) The configuration information includes a list of triggering states; All triggering states in the list are information specifying aperiodic reference signals for radio link monitoring or beam failure recovery, or Some of the triggering states in the list are information specifying aperiodic reference signals for radio link monitoring or beam failure recovery. 3. A terminal as described in claim 2 or 3. (Section 5) A transmitter that transmits configuration information including a purpose of the non-periodic reference signal to a terminal, The transmission unit transmits downlink control information, and in the terminal, based on a trigger by the downlink control information, a measurement for radio link monitoring or beam failure recovery is performed by a non-periodic reference signal designated by the setting information according to the purpose. Base station. (Section 6) receiving configuration information from a base station, the configuration information including a purpose of the aperiodic reference signal; performing measurement for radio link monitoring or beam failure recovery using a non-periodic reference signal designated by the setting information according to the purpose, based on a trigger by downlink control information received from the base station; A measurement method performed by a terminal, comprising:

[0202] Any of the above configurations provides a technique that enables a terminal to appropriately perform failure detection and recovery in a wireless communication system. According to the third aspect, a purpose can be set for each triggering state. According to the fourth aspect, variations in the triggering state list can be realized.

[0203] (Hardware configuration) The block diagrams (FIGS. 22 and 23) 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 of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically combined, or may be realized using two or more devices that are physically or logically separated and directly or indirectly connected (e.g., using wires, wirelessly, etc.) and these multiple devices. The functional blocks may be realized by combining the one device or the multiple devices with software.

[0204] 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, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocation, mapping, assignment, etc. For example, a functional block (component) that performs the function of transmission is called a transmitting unit or a transmitter. In either case, as described above, there is no particular limitation on the method of realization.

[0205] For example, the base station 10, the terminal 20, 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. 24 is a diagram showing an example of a hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. The above-mentioned base station 10 and the terminal 20 may be physically configured as a computer device including a processor 1001, a storage device 1002, an auxiliary storage device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0206] In the following description, the term "apparatus" can be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the base station 10 and the terminal 20 may be configured to include one or more of the devices shown in the figure, or may be configured to exclude some of the devices.

[0207] Each function in the base station 10 and the terminal 20 is realized by loading a specific software (program) onto hardware such as a processor 1001, a memory device 1002, etc., so that the processor 1001 performs calculations, controls communications by the communication device 1004, and controls at least one of reading and writing of data in the memory device 1002 and the auxiliary memory device 1003.

[0208] The processor 1001 controls the entire computer by running, for example, an operating system. 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, the above-mentioned control unit 140, control unit 240, etc. may be realized by the processor 1001.

[0209] Moreover, the processor 1001 reads out a program (program code), a software module, data, or the like from at least one of the auxiliary storage device 1003 and the communication device 1004 to the storage device 1002, and executes various processes according to the program. As the program, a program that causes a computer to execute at least a part of the operations described in the above-mentioned embodiment is used. For example, the control unit 140 of the base station 10 shown in FIG. 22 may be realized by a control program stored in the storage device 1002 and operated by the processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in FIG. 23 may be realized by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above-mentioned various processes have been described as being executed by one processor 1001, they may be executed by two or more processors 1001 simultaneously or sequentially. The processor 1001 may be implemented by one or more chips. The program may be transmitted from a network via a telecommunication line.

[0210] The storage device 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 Erasable Programmable ROM (EEPROM), a Random Access Memory (RAM), etc. The storage device 1002 may also be called a register, a cache, a main memory (primary storage device), etc. The storage device 1002 can store a program (program code), software modules, etc. that are executable to implement a communication method according to an embodiment of the present disclosure.

[0211] The auxiliary storage device 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, etc. The above-mentioned storage medium may be, for example, a database, a server, or other suitable medium including at least one of the storage device 1002 and the auxiliary storage device 1003.

[0212] The communication device 1004 is hardware (transmission and 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, a transmission and reception antenna, an amplifier unit, a transmission and reception unit, a transmission line interface, etc. may be realized by the communication device 1004. The transmission and reception unit may be implemented as a transmission unit and a reception unit that are physically or logically separated from each other.

[0213] 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, an 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).

[0214] In addition, each device such as the processor 1001 and the storage device 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.

[0215] Furthermore, the base station 10 and the 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 by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0216] (Supplementary embodiment) Although the embodiment of the present invention has been described above, the disclosed invention is not limited to such an embodiment, and those skilled in the art will understand various modifications, modifications, alternatives, replacements, and the like. Although the description has been given using specific numerical examples to facilitate understanding of the invention, unless otherwise specified, those numerical values ​​are merely examples and any appropriate values ​​may be used. The division of items in the above description is not essential to the present invention, and matters described in two or more items may be used in combination as necessary, and matters described in one item may be applied to matters described in another item (as long as there is no contradiction). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operations of multiple functional units may be physically performed by one part, or the operations of one functional unit may be physically performed by multiple parts. The order of the processing procedures described in the embodiment may be changed as long as there is no contradiction. For convenience of the processing description, the base station 10 and the terminal 20 have been described using functional block diagrams, but such devices may be realized by hardware, software, or a combination thereof. The software operated by the processor possessed by the base station 10 in accordance with an embodiment of the present invention and the software operated by the processor possessed by the terminal 20 in accordance with an embodiment of the present invention may each be stored in a random access memory (RAM), flash memory, read only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

[0217] Furthermore, 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 may be performed by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination of these. Furthermore, the RRC signaling may be called an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

[0218] Each aspect / embodiment described in the present disclosure may be applied to at least one of systems using LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), and other suitable systems, and next-generation systems extended based on these. In addition, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G, etc.) may be applied.

[0219] The steps, sequences, flow charts, etc. of each aspect / embodiment described herein 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.

[0220] In this specification, a specific operation performed by the base station 10 may be performed by its upper node in some cases. In a network consisting of one or more network nodes having the base station 10, it is clear that various operations performed for communication with the terminal 20 may be performed by at least one of the base station 10 and other network nodes other than the base station 10 (e.g., MME or S-GW, etc., but are not limited to these). Although the above example illustrates a case in which there is one other network node other than the base station 10, the other network node may be a combination of multiple other network nodes (e.g., MME and S-GW).

[0221] The information or signals described in the present disclosure may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer), or may be input / output via multiple network nodes.

[0222] The input and output information may be stored in a specific location (e.g., memory) or may be managed using a management table. The input and output information may be overwritten, updated, or added to. The output information may be deleted. The input information may be transmitted to another device.

[0223] In the present disclosure, the determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0224] 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.

[0225] 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 and / or wireless 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.

[0226] 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.

[0227] In addition, the terms described in this disclosure and the terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may be a signal (signaling). Also, a signal may be a message. Also, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0228] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0229] 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 an index.

[0230] The names used for the above-mentioned parameters are not limiting in any way. Moreover, the formulas using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., 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.

[0231] In the present disclosure, terms such as "base station (BS)", "radio base station", "base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "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.

[0232] 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 divided into multiple smaller areas, and each smaller area can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head). 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.

[0233] In this disclosure, the terms "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. may be used interchangeably.

[0234] A mobile station may also be referred to by those skilled in the art 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.

[0235] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a 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 IoT (Internet of Things) device such as a sensor.

[0236] Furthermore, the base station in the present disclosure may be read as a 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 terminal is replaced with communication between a plurality of terminals 20 (which may be called, for example, D2D (Device-to-Device) or V2X (Vehicle-to-Everything)). In this case, the 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 communication between terminals (for example, "side"). For example, an uplink channel, a downlink channel, etc. may be read as a side channel.

[0237] Similarly, the terminal in the present disclosure may be read as a base station. In this case, the base station may be configured to have the functions of the terminal described above.

[0238] As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in a memory), and the like. In addition, "judgment" and "decision" can include considering resolving, selecting, choosing, establishing, comparing, etc., to be a "judgment" or "decision." In other words, "judgment" and "decision" can include considering some action to be a "judgment" or "decision." In addition, "judgment" can be interpreted as "assuming," "expecting," "considering," etc.

[0239] 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." As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0240] The reference signal may be abbreviated as RS (Reference Signal) and may be called a pilot depending on the applicable standard.

[0241] 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."

[0242] 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.

[0243] The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

[0244] 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.

[0245] A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further 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.

[0246] The numerology may be communication parameters that apply to the transmission and / or reception of a signal or channel, such as, for example, at least one of 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 particular filtering operation that the transceiver performs in the frequency domain, a particular windowing operation that the transceiver performs in the time domain, etc.

[0247] 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 be a time unit based on numerology.

[0248] 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 (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0249] A radio frame, a subframe, a slot, a minislot, and a symbol each represent a time unit for transmitting a signal. The radio frame, the subframe, the slot, the minislot, and the symbol may each be referred to by a different name.

[0250] For example, one subframe may be called a transmission time interval (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, a minislot, or the like, instead of a subframe. Also, one slot may be called a unit time. The unit time may be different for each cell depending on the numerology.

[0251] 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 wireless resources (such as frequency bandwidth and transmission power that can be used by each terminal 20) to each terminal 20 in TTI units. Note that the definition of TTI is not limited to this.

[0252] 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.

[0253] 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.

[0254] A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE 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.

[0255] 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.

[0256] 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, for example, 12. The number of subcarriers included in an RB may be determined based on the numerology.

[0257] In addition, the time domain of the RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI in length. Each of one TTI, one subframe, etc. may be composed of one or more resource blocks.

[0258] Note that 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, or the like.

[0259] 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.

[0260] 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 an 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.

[0261] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0262] 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".

[0263] The above-mentioned 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.

[0264] In this disclosure, where articles have been added due to translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0265] 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."

[0266] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched according to execution. In addition, notification of specific information (e.g., notification that "X is the case") is not limited to being done explicitly, but may be done implicitly (e.g., not notifying the specific information).

[0267] Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure. [Explanation of symbols]

[0268] 10 base station 110 Transmitter 120 Receiving unit 130 Setting section 140 Control section 20 Terminals 210 Transmitter 220 Receiving unit 230 Setting section 240 Control Unit 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication equipment 1005 Input Device 1006 Output device

Claims

1. A receiving unit that receives downlink control information from a base station; a control unit that performs measurement for radio link monitoring or beam failure recovery using a non-periodic reference signal received from the base station based on a trigger by the downlink control information, The control unit determines, based on a format of the downlink control information, that the non-periodic reference signal is a reference signal to be used for radio link monitoring or beam failure recovery. Terminal.

2. A receiving unit that receives downlink control information from a base station; a control unit that performs measurement for radio link monitoring or beam failure recovery using a non-periodic reference signal received from the base station based on a trigger by the downlink control information, The control unit determines, based on the RNTI used in scrambling the downlink control information, that the non-periodic reference signal is a reference signal to be used for radio link monitoring or beam failure recovery. Terminal.

3. A transmitter for transmitting downlink control information to a terminal, the transmitting unit transmits an aperiodic reference signal based on a trigger by the downlink control information, and the terminal performs measurement for radio link monitoring or beam failure recovery by the aperiodic reference signal; In the terminal, it is determined that the non-periodic reference signal is a reference signal to be used for radio link monitoring or beam failure recovery based on a format of the downlink control information. Base station.

4. A transmitter for transmitting downlink control information to a terminal, the transmitting unit transmits an aperiodic reference signal based on a trigger by the downlink control information, and the terminal performs measurement for radio link monitoring or beam failure recovery by the aperiodic reference signal; In the terminal, the non-periodic reference signal is determined to be a reference signal to be used for radio link monitoring or beam failure recovery based on the RNTI used for scrambling the downlink control information. Base station.

5. receiving downlink control information from a base station; A measurement method in a terminal, comprising: a control step of performing a measurement for radio link monitoring or beam failure recovery by a non-periodic reference signal received from the base station based on a trigger by the downlink control information, In the control step, the terminal determines, based on a format of the downlink control information, that the non-periodic reference signal is a reference signal to be used for radio link monitoring or beam failure recovery. Measurement method.

6. receiving downlink control information from a base station; A measurement method in a terminal, comprising: a control step of performing a measurement for radio link monitoring or beam failure recovery by a non-periodic reference signal received from the base station based on a trigger by the downlink control information, In the control step, the terminal determines that the non-periodic reference signal is a reference signal to be used for radio link monitoring or beam failure recovery, based on the RNTI used in scrambling the downlink control information. Measurement method.

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