Terminal, base station, and measuring method

Abstract

To provide a technique for enabling a terminal to appropriately perform failure detection and recovery in a wireless communication system.SOLUTION: A terminal includes a receiving part for receiving downlink control information from a base station, and a control part for performing measurement for wireless link monitoring or recovery from beam failure with a non-periodic reference signal received from the base station, based on the format of the downlink control information.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

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

[0003] In the NR system, in order to expand the frequency band, the use of a frequency band licensed to a communications carrier (operator) (a frequency band different from the licensed band, also referred to as an unlicensed band, unlicensed carrier, or unlicensed CC) is supported.

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Non-Patent Document 5

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] In NR, various functions regarding the detection and recovery of radio link failures are defined (for example, Non-Patent Documents 2 to 5). Also, in NR, various functions regarding the detection and recovery of beam failures are defined (for example, Non-Patent Documents 2 to 5).

[0006] However, terminals in accordance with existing NR regulations assuming frequency bands up to 52.6 GHz may not be able to appropriately perform radio link / beam failure detection and recovery in high frequency bands such as 52.6 to 114.25 GHz where the use of unlicensed bands is assumed.

[0007] The present invention has been made in view of the above points, and an object thereof is to provide a technique that enables a terminal to appropriately perform failure detection and recovery in a radio communication system.

MEANS FOR SOLVING THE PROBLEM

[0008] According to the disclosed technique, a receiving unit that receives downlink control information from a base station, a control unit that performs measurements for radio link monitoring or beam failure recovery by means of an aperiodic reference signal received from the base station based on the format of the downlink control information are provided in a terminal.

ADVANTAGES OF THE INVENTION

[0009] According to the disclosed technique, a technique that enables a terminal to appropriately perform failure detection and recovery in a radio communication system is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]

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Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments.

[0012] In the operation of the wireless communication system according to the embodiment of the present invention, existing technologies are appropriately used. The existing technology is, for example, existing NR. The wireless communication system (base station 10 and terminal 20) in the present embodiment basically operates according to existing regulations (e.g., Non-Patent Documents 1 to 5). However, in order to solve problems in the case of assuming the use of high-frequency bands or unlicensed bands, the base station 10 and the terminal 20 also execute operations not included in existing regulations. In the description of the examples described later, operations not included in existing regulations are mainly described. Note that all the numerical values described below are examples.

[0013] Also, in the embodiment of the present invention, the duplex method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or another method (e.g., Flexible Duplex, etc.).

[0014] In addition, in the embodiments of the present invention, that the radio parameters or the like are "configured" may mean that predetermined values are pre-configured, or that radio parameters notified from the base station 10 or the terminal 20 are configured.

[0015] Note that in the embodiments described below, the aperiodic CSI-RS is taken as an example of the reference signal used for RLM / BFR. However, the aperiodic reference signals applicable to the technology according to the present invention are not limited to the aperiodic CSI-RS. For example, as the aperiodic reference signal applicable to the technology according to the present invention, an aperiodic synchronization signal may be used, or a reference signal other than the SCI-RS may be used.

[0016] (System Configuration)

[0017] FIG. 1 is a diagram for explaining a wireless communication system according to an embodiment of the present invention. The wireless communication system according to the embodiment of the present invention includes a base station 10 and a terminal 20 as shown in FIG. 1. In FIG. 1, one base station 10 and one terminal 20 are shown, but 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 terminal 20. The physical resources of the 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 spacings (SCS) of at least 15 kHz, 30 kHz, 120 kHz, and 240 kHz are supported. Also, regardless of the SCS, a resource block is composed of a predetermined number (for example, 12) of consecutive subcarriers.

[0020] When performing initial access, the 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] Also, in the time domain, a slot is composed of a plurality of OFDM symbols (for example, 14 regardless of the subcarrier spacing). Hereinafter, the OFDM symbol is referred to as a "symbol". A slot is a scheduling unit. Also, a subframe of 1 ms is defined, and a frame consisting of 10 subframes is defined. Note that 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 the DL (Downlink) and receives control information or data from the terminal 20 in the UL (Uplink). Both the base station 10 and the terminal 20 are capable of performing beamforming for signal transmission and reception. Also, both the base station 10 and the terminal 20 are capable of applying communication by MIMO (Multiple Input Multiple Output) to the DL or UL. Also, 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, and a communication module for M2M (Machine-to-Machine). As shown in FIG. 1, the terminal 20 receives control information or data from the base station 10 in the DL and transmits control information or data to the base station 10 in the UL, thereby using various communication services provided by the wireless communication system.

[0024] The terminal 20 is capable of performing carrier aggregation in which a plurality of cells (a plurality of CCs (Component Carriers)) are bundled 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 is also used.

[0025] Figure 2 shows a configuration example of a wireless communication system when NR-DC (NR-Dual connectivity) is executed. As shown in Figure 2, a base station 10A serving as an MN (Master Node) and a base station 10B serving as an SN (Secondary Node) 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 the MN is called an MCG (Master Cell Group), and a cell group provided by the base station 10B which is the SN is called an SCG (Secondary Cell Group). Also, in DC, the MCG is composed of one PCell and one or more SCells, and the SCG is composed of one PSCell (Primary SCell) and one or more SCells. Note that in this specification, a CC (Component Carrier) and a cell may be used synonymously. Also, the PCell and the PSCell may be called an SPCell.

[0027] In the wireless communication system of this embodiment, when an unlicensed band is used, LBT (Listen Before Talk) is executed. The base station 10 or the terminal 20 performs signal sensing, 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 the unlicensed band, and there may be cases where LBT is not performed in the unlicensed band.

[0028] (Regarding the frequency band) FIG. 3 shows an example of a frequency band used in existing NR and a frequency band used in the wireless communication system according to the present embodiment. As frequency bands (which may also be referred to as frequency ranges) in existing NR, there are two frequency bands: FR1 (0.41 GHz to 7.125 GHz) and FR2 (24.25 GHz to 52.6 GHz). As shown in FIG. 3, in FR1, 15 kHz, 30 kHz, and 60 kHz are supported as SCS, and 5 to 100 MHz is supported as the bandwidth (BW). In FR2, 60 kHz, 120 kHz, and 240 kHz (only for SSB) are supported as SCS, and 50 to 400 MHz is supported 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 that is not used in existing NR (for example, 52.6 GHz to 114.25 GHz) is also used. This frequency band may be referred to as FR4.

[0030] Also, in the present embodiment, it is assumed that as the frequency band is extended as described above, an SCS wider than the existing SCS is used. For example, 480 kHz or an SCS wider than 480 kHz is used as the SCS for SSB and PDCCH / PDSCH.

[0031] In the high frequency band, it is assumed that a large number of narrow beams are used to compensate for large propagation losses. Also, as the SCS, an SCS wider than the existing SCS of FR2 (for example, 480 kHz, 960 kHz) is used.

[0032] FIG. 4 is a diagram showing the relationship between SCS and symbol length (the time length of a symbol). As shown in FIG. 4, as the SCS becomes wider, the symbol length (the time length of a symbol) becomes shorter. Also, assuming that the number of symbols per slot is constant (that is, 14 symbols), as the SCS becomes wider, the slot length becomes shorter.

[0033] In this way, when the number of beams increases and each beam becomes narrower, and the SCS becomes wider, if the terminal 20 and the base station 10 operate according to the conventional regulations, it may not be possible to appropriately detect and recover from a failure of the radio link / beam. For example, as will be described later, it is also assumed that the LBT fails frequently. In that case, it may not be possible to appropriately measure the reference signal for detecting and recovering from a failure of the radio link / beam.

[0034] Hereinafter, a technique for the terminal 20 and the base station 10 to appropriately detect and recover from a failure of the radio link / beam will be described.

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

[0036] In S100, the terminal 20 transmits the UE capability information to the base station 10. Based on this capability information, the base station 10 can determine, for example, the information to be transmitted to the terminal 20 in S101 and S102 below.

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

[0038] In S102, the base station 10 transmits a trigger to the terminal 20 by means of DCI, and the terminal 20 receives the trigger. The trigger is, for example, a trigger for the terminal 10 to perform measurements of Aperiodic CSI-RS for RLM / BFR as described later. In the present 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 specified time, in S103, the terminal 20 receives the Aperiodic CSI-RS, and in S104, performs measurements for, for example, radio link / beam failure detection and recovery.

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

[0041] (RLM / RLF) First, RLM / RLF is described. The terminal 20 (and the base station 10) performs RLM (Radio Link Monitoring) and when detecting RLF (Radio Link Failure), RRC connection re-establishment and the like are executed.

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

[0043] N310 is a threshold of the number of consecutive out-of-sync indications, and when the number of consecutive out-of-sync indications reaches N310, the timer of 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, it executes RRC connection re-establishment. T311 starts at the start of the RRC connection re-establishment procedure in cell reselection and stops when cell reselection is successful. When T311 expires, the terminal 20 enters the 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 (for example, a functional part of the physical layer) detects out-of-sync (radio link quality degradation), it notifies an out-of-sync indication to an upper layer (for example, a functional part of the RRC).

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

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

[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" That is, the in-sync indication is a certain threshold Q in The index of the P-CSI-RS for which a radio link quality measurement equal to or greater than the above is obtained, or (or may also be) the index of the SS / PBCH block (hereinafter may be referred to as SSB). Also, the index of the target P-CSI-RS and the index of the SSB are within the set "q1~". q1~ is a parameter notified from the base station 10 to the terminal 20 by RRC signaling, for example, by the candidateBeamRSList for radio link quality measurement. Note that the radio 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 that the radio link quality of all resources in the set "q0~" that the terminal 20 uses for radio link quality assessment is a certain threshold Qout Information to be notified when the situation is worse than [specific condition]. q0~ is, for example, a set of indexes of P-CSI-RS notified from base station 10 to terminal 20 by RRC signaling through failureDetectionResources.

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

[0052] First, with reference to FIG. 7, an operation example of BFD / BFR in PCell / PSCell (BFR of R-15) will be described.

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

[0054] All reference signals in S10 are a set (failure Detection resources) of reference signal (index) settings from base station 10 to terminal 20 for which measurements are made for beam failur detection, and this is called q0. For example, 8 is set for this.

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

[0056] In S12, the terminal 12 transmits a PRACH (preamble) on a PRACH occasion corresponding to the selected new beam. The terminal 20 monitors a BFR response (PDCCH) in a BFR response window starting 4 slots later.

[0057] After the terminal 20 receives a BFR response (PDCCH) in S13, 28 symbols later, assuming that the PDCCH monitored in CORESET#0 is in a QCL relationship with the new beam (reference signal), the terminal 20 monitors the PDCCH in CORESET#0.

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

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

[0060] All the reference signals in S20 are a set (failure Detection resources) of reference signal (index) settings from the base station 10 to the terminal 20 for which measurements are made for beam failure detection, and this is called q0. For example, 8 is set for this.

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

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

[0063] After receiving the PDCCH (the PDCCH in S25) that schedules the PUSCH, 28 symbols later, the terminal 20 monitors the PDCCH assuming that the PDCCH to be monitored in subsequent SCell is in a QCL relationship with the new beam (reference signal). Also, 28 symbols later, the terminal 20 transmits the PUSCH to be transmitted in subsequent SCell using a spatial domain filter corresponding to the spatial domain filter of the new beam (reference signal). That is, QCL is also updated for the PUSCH.

[0064] (Regarding setting information such as reference signals, etc.) FIG. 9 shows an example of setting 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 setting information related to BFR (Non-Patent Document 2) (Regarding the use of aperiodic reference signals) Since the frequency band of 52.6 to 71 GHz assumed to be used in the wireless communication system of the present embodiment includes an unlicensed spectrum (unlicensed band), in the wireless communication system of the present embodiment, LBT may be required.

[0065] In RLM and BFR based on the above-described 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 at the base station 10, for example, as shown in FIG. 11, at each transmission timing of the reference signal, there are cases where LBT succeeds and cases where it fails. Therefore, it becomes impossible to periodically transmit the reference signal from the base station 10, and it is assumed that the frequency at which the terminal 20 can receive the reference signal decreases. Therefore, there is a possibility that RLM and BFR cannot be appropriately executed.

[0067] In order to solve the above problems, instead of a periodic reference signal, an aperiodic reference signal based on DCI triggering is used as the reference signal used by the terminal 20 for beam monitoring / selection in RLM or BFR. The aperiodic reference signal is, for example, 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 the reference signal at the timing when LBT succeeds.

[0069] The terminal 20 executes RLM and BFR by measuring the reference signal received aperiodically based on a trigger, for example, by performing the count process and the like described with reference to FIGS. 6, 7, 8, etc. Thereby, when LBT is required, RLF and BFR can be appropriately executed without being affected by LBT failure. Note that the technology according to the present invention is also applicable when LBT is not assumed.

[0070] (Regarding Aperiodic CSI report triggering) Here, the setting information and the like of Aperiodic CSI report triggering based on the existing technology (Non-Patent Documents 2, 5, etc.) will be described with reference to FIG. 12.

[0071] To perform aperiodic CSI report triggering, first, a CSI-AperiodicTriggerStateList is set from base station 10 to terminal 20 in RRC. The CSI-AperiodicTriggerStateList includes one or more CSI-AperiodicTriggerStates with indices.

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

[0073] One CSI-AperiodicTriggerState is associated with one or more Report settings, and the 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 with 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, the CSI-AperiodicTriggerStateList includes one or more CSI-AperiodicTriggerStates, and each CSI-AperiodicTriggerState includes one or more resourceSets. The resourceSet indicates an NZP-CSI-RS-ResourceSet for channel measurement.

[0075] (Regarding detailed issues) In order to appropriately execute RLM / BFR even in a situation where an LBT failure occurs, when applying Aperiodic CSI-RS to RLM / BFR, issues arise regarding 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 it is, the triggered CSI-RS will be used for CSI / beam reporting or tracking according to the ReportQuantity. Therefore, in order to support Aperiodic CSI-RS for RLM / BFR, it is necessary to notify the terminal 20 for which purpose (CSI / beam reporting, tracking, or RLM / BFR) the triggered Aperiodic CSI-RS is used.

[0077] Therefore, in this embodiment, an extension of the trigger DCI and an extension of the RRC configuration are proposed. Details will be described later.

[0078] Note that as methods for supporting Aperiodic CSI-RS triggering for RLM / BFR, the following Alt1 and Alt2 are conceivable, but in this embodiment, considering the impact on the specification, Alt1 is adopted.

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

[0080] Alt2: Design a new procedure to support Aperiodic CSI-RS triggers for RLM / BFR.

[0081] Hereinafter, specific examples of the present embodiment will be described with reference to Examples 1 to 4 and modification examples. Any one or more or all of Examples 1 to 4 can be implemented in combination.

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

[0083] <Example 1-1> In Example 1-1, only 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 the beam applied to the Aperiodic CSI-RS.

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

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

[0086] Alt2: No restrictions are imposed on the beam of the Aperiodic CSI-RS used.

[0087] <Example 1-2> In Example 1-2, both Aperiodic CSI-RS and Periodic CSI-RS / SSB can be used for RLM / BFR. That is, in addition to being used in existing applications such as CSI / beam reporting, the existing Periodic CSI-RS / SSB can also be used for RLM / BFR, and furthermore, Aperiodic CSI-RS can be used for RLM / BFR.

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

[0089] Alt1: The beam of Aperiodic CSI-RS used in RLM / BFR is the same as the beam set for Periodic CSI-RS also used in RLM / BFR. This case is an assumption of using Aperiodic CSI-RS as an auxiliary during the period when Periodic CSI-RS is not transmitted.

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

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

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

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

[0094] <Example 1-3> In Example 1-3, 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 an operation to cause the terminal 20 to use Aperiodic CSI-RS for RLM / BFR (by DCI or RRC configuration described later).

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

[0097] Note that the same example (Example 1-1, Example 1-2, or Example 1-3) may be applied to both RLM and BFR, or different examples may be applied to RLM and BFR respectively.

[0098] (Example 2) Next, Example 2 will be described. In Example 2, a DCI obtained by extending the existing DCI is used to trigger Aperiodic CSI-RS for RLM / BFD.

[0099] An operation example of Example 2 will be described with reference to FIG. 5 described above. In S101, setting information regarding 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, an aperiodic CSI-RS trigger (a measurement trigger for terminal 20) is transmitted from base station 10 to terminal 20 by the extended DCI in Embodiment 2. This DCI includes information instructing the use of aperiodic CSI-RS for RLM / BFD.

[0101] After receiving the DCI, terminal 20 receives aperiodic CSI-RS and performs measurements after a certain period of time (S103, S104). These measurements are for RLM / BFD. From the perspective of base station 10, the transmission of aperiodic CSI-RS is triggered by the DCI transmission after a certain period of time.

[0102] Hereinafter, more specific examples will be described as Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3. Any two or all of Embodiment 2-1, Embodiment 2-2, and Embodiment 2-3 may be combined and implemented.

[0103] <Embodiment 2-1> In Embodiment 2-1, the DCI field is extended (such as adding a new field). As the DCI format and the RNTI that scrambles the DCI, existing formats (e.g., DCI format 0_1, DCI format 0_2) and existing RNTIs may be used.

[0104] Alternatively, instead of extending the DCI field, a different interpretation (re-interpretation) 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 value of the purpose indication field.

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

[0107] Purpose 1: Trigger for existing purposes (e.g., beam / CSI reporting, tracking) Purpose 2: Trigger for RLM measurement Purpose 3: Trigger for BFD measurement Purpose 4: Trigger for both RLM measurement and BFD measurement Purpose 5: Trigger for RLM measurement or BFD measurement, or both RLM measurement and BFD measurement Purpose 6: Purpose 1 + Purpose 2 / 3 / 4 Purpose 7: Purpose 1 + Purpose 5 Regarding Purpose 5 among the above Purposes 1 to 7, the terminal 20 that has received the DCI may refer to the RRC configuration to identify its purpose (RLM, BFD, or both). Also, Purposes 6 and 7 indicate that they can be used for both existing purposes and RLM / BFD purposes.

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

[0109] Upon receiving DCI of a new DCI format from the base station 10, the terminal 20 that has detected the new DCI format determines that the DCI is DCI for triggering Aperiodic CSI-RS for RLM / BFD, and uses the CSI-RS specified by the DCI for measurements for RLM / BFD.

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

[0111] Upon being able to decode the DCI using the new RNTI, the terminal 20 determines that the DCI is DCI for triggering Aperiodic CSI-RS for RLM / BFD, and uses the CSI-RS specified by the DCI for measurements for RLM / BFD.

[0112] <Other examples (variations)> The DCI in Examples 2-1, 2-2, and 2-3 may all be UE-specific (terminal-specific), group common, or cell common.

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

[0114] <Effect of Example 2> The terminal 20 that receives the DCI of Example 2 can determine whether the Aperiodic CSI-RS triggered by the DCI is to be used for either CSI / beam reporting or RLM / BFD. Also, since the purpose of the trigger can be accurately determined by the DCI, the existing procedure (Rel-16 A-CSI report triggering procedure) can be used, and the existing RRC configuration information can be used.

[0115] (Example 3) Next, Example 3 will be described. In Example 3, in order to realize the trigger of the Aperiodic CSI-RS for RLM / BFD, RRC configuration information extended from the existing RRC configuration information is used.

[0116] An operation example of Example 3 will be described with reference to FIG. 5. In S101, configuration information regarding the Aperiodic CSI-RS is transmitted from the base station 10 to the terminal 20 by an RRC message. The configuration information here is, for example, extended (or modified) from the existing configuration information disclosed in Non-Patent Document 2.

[0117] In S102, for example, the trigger of the Aperiodic CSI-RS (measurement trigger for the terminal 20) is transmitted from the base station 10 to the terminal 20 by an existing DCI. This DCI includes the CSI request field described in FIG. 11.

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

[0119] In Example 3, 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] Hereinafter, more specific examples will be described as Example 3-1, Example 3-2, Example 3-3, and Example 3-4. Any two, any three, or all of Example 3-1, Example 3-2, Example 3-3, and Example 3-4 may be combined and implemented.

[0121] <Example 3-1> Conventionally, only periodic measurements could be made for RLM and BFD measurements. Therefore, in Example 3-1, it is possible to perform an aperiodic setting for CSI-RS for RLM and BFD.

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

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

[0124] Alt2: Whether the aperiodic CSI-RS for RLM / BFD associated with CSI-AperiodicTriggerState can also be used for existing applications (such as CSI / beam reporting, etc.) may be specified by an RRC parameter in the aperiodic CSI-RS setting information.

[0125] <Specific Example of Example 3-1> Describe a specific example of the configuration information in Embodiment 3-1.

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

[0127] RadioLinkMonitoringRS-r17 is set as the configuration information of the Aperipdic CSI-RS for RLM / BFD associated with the CSI-AperiodicTriggerState. Thereby, the terminal 20 receiving the trigger by DCI can perform the measurement for RLM / BFD using the Aperipdic CSI-RS set by RadioLinkMonitoringRS-r17 associated with the specified CSI-AperiodicTriggerState.

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

[0129] An example of RadioLinkMonitoringRS-r17 assuming Alt2 is shown in FIG. 14. Depending on the purpose shown in FIG. 14, it is possible to specify whether the use of the Aperipdic CSI-RS set by RadioLinkMonitoringRS-r17 is for RLM (rlf in FIG. 14), BFR (beamFailure in FIG. 14), or both.

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

[0131] As shown in FIG. 15, TriggeringPurpose is included. TriggeringPurpose indicates the purpose (usage) of all Aperipdic CSI-RS associated with this CSI-AperiodicTriggerState-r17. As TriggeringPurpose, RLM / BFD, existing purposes (CSI / beam reporting), etc. can be set. In the example of FIG. 15, it is shown that a subset of purpose 1 to 7 described in Example 2 can be set.

[0132] Suppose that the terminal 20 configured with the configuration information including the above CSI-AperiodicTriggerState-r17 is specified a specific CSI-AperiodicTriggerState-r17 by the CSI request field of DCI.

[0133] For example, if the terminal 20 determines that the purpose is RLM / BFD from TriggeringPurpose in the CSI-AperiodicTriggerState-r17, it uses the Aperipdic CSI-RS associated with the CSI-AperiodicTriggerState-r17 for RLM / BFD measurement.

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

[0135] <Effect of Example 3-2> In Example 3-2, while directly using the existing (Rel-16) Aperipdic CSI-RS report triggering procedure, the Aperipdic CSI-RS for RLM / BFD can be realized.

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

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

[0138] As shown in FIG. 16, it is possible to set the TriggeringPurpose for each CSI-AssociatedReportConfigInfo in the associatedReportConfigInfoList. The TriggeringPurpose indicates the purpose of the corresponding Aperipdic CSI-RS associated with the CSI-AssociatedReportConfigInfo. As the TriggeringPurpose, it is possible to set RLM / BFD, existing purposes (CSI / beam reporting), etc. In the example of FIG. 16, it is shown that a subset of purposes 1 to 7 described in Example 2 can be set.

[0139] Suppose that the terminal 20 with the configuration information including the above CSI-AperiodicTriggerState-r17 is specified a specific CSI-AperiodicTriggerState-r17 by the CSI request field of the DCI.

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

[0141] For example, if the terminal 20 determines from the TriggeringPurpose of a certain CSI-AssociatedReportConfigInfo in the CSI-AperiodicTriggerState-r17 that the purpose is both RLM and CSI reporting, it uses the Aperipdic CSI-RS associated with the CSI-AssociatedReportConfigInfo for RLM measurement and also for CSI reporting measurement.

[0142] <Effects of Example 3-3, etc.> Even in the case of Embodiment 3-3, it is possible to realize the Aperiodic CSI-RS for RLM / BFD while directly using the existing (Rel-16) Aperipdic CSI-RS report triggering procedure.

[0143] Also, in Embodiment 3-3, in one CSI-AperiodicTriggerState, for each of a plurality of different report settings, a purpose can be set. Therefore, for each of the plurality of different report settings in one CSI-AperiodicTriggerState, the associated Aperipdic CSI-RS can be used for each purpose.

[0144] On the other hand, in Embodiment 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 the Aperipdic CSI-RS associated with the plurality of different report settings in one CSI-AperiodicTriggerState are used for the same purpose.

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

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

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

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

[0149] Also, for example, by interpreting the value of the CSI request field in the DCI differently from the conventional interpretation, for example, if the value of the CSI request field in the DCI is greater than or equal to a certain value, it indicates that the new CSI-AperiodicTriggerStateList is used, and otherwise it indicates that the existing CSI-AperiodicTriggerStateList is used.

[0150] In Alt2:Alt12, a CSI-AperiodicTriggerStateList including the CSI-AperiodicTriggerState for existing purposes (such as CSI reporting) and the new CSI-AperiodicTriggerState for RLM / BFD is used. Fig. 18 shows an example of the CSI-AperiodicTriggerStateList of Alt2. As shown in Fig. 18, the CSI-AperiodicTriggerStateList of Alt1 includes the existing CSI-AperiodicTriggerState and CSI-AperiodicTriggerStateRlm-r17 which is the new CSI-AperiodicTriggerState for RLM / BFD.

[0151] As the DCI for triggering in Alt2, the existing DCI can be used. The terminal 20 uses the existing CSI-AperiodicTriggerState or CSI-AperiodicTriggerStateRlm-r17 according to the CSI request field of the DCI received from the base station 10.

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

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

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

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

[0156] In the example of FIG. 20, what is indicated by NZP-CSI-RS-ResourceId corresponds to the said list. Regarding the purpose of the Aperipdic CSI-RS resources for RLM / BFD, it can be set commonly for the set of lists of Aperipdic CSI-RS resources (using PurposeCommon), or can be set individually for the list of Aperipdic CSI-RS resources (using PurposeSeparate).

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

[0158] (Example 4) Next, Example 4 will be described. Example 4 is an example regarding new beam selection in BFR. That is, Example 4 is an example that enables the terminal 20 to perform measurements by Aperiodic CSI-RS for the purpose of new beam selection in BFR.

[0159] In order to enable the terminal 20 to perform measurements using Aperiodic CSI-RS for the purpose of new beam selection in BFR, the techniques described in Example 2 and Example 3 can be applied. That is, in the content described in Example 2 and Example 3, replacing "RLM / BFD" with "new beam selection" results in Example 4. More specifically, it is as follows in Example 4-1 and Example 4-2 below.

[0160] <Example 4-1> Example 4-1 corresponds to Example 2. That is, by extending the DCI, it becomes possible for the terminal 20 to perform measurements using Aperiodic CSI-RS for the purpose of new beam selection in BFR. In Example 2, replacing "RLM / BFD" with "new beam selection" results in Example 4-1.

[0161] <Example 4-2> Example 4-2 corresponds to Example 3. That is, by extending the RRC configuration information, it becomes possible for the terminal 20 to perform measurements using Aperiodic CSI-RS for the purpose of new beam selection in BFR. Basically, in Example 3, replacing "RLM / BFD" with "new beam selection" results in Example 4-2.

[0162] As a more specific example, an example of the configuration information used in Example 4-2 with respect to Example 3-1 is shown in FIG. 21. As shown in FIG. 21, candidateBeamRSList-r17, which is a list of beams detected by measurements of Aperiodic CSI-RS, is configured. The individual Aperiodic CSI-RS resources in candidateBeamRSList-r17 are configured by PRACH-A-CSI-ResourceDedicatedBFR-r1.

[0163] In Example 4-2 with respect to Example 3-1, the terminal 20 detects a new beam by measuring the Aperiodic CSI-RS specified by candidateBeamRSList-r17 associated with the triggering state specified by the DCI.

[0164] For Examples 3-2 to 3-4, in Examples 3-2 to 3-4, Example 4-2 is obtained by replacing the objective of "RLM / BFD" with "new beam selection". Also, the correspondence relationship between the Aperiodic CSI-RS resources that can be used for new beam selection and the PRACH resources may be set.

[0165] (Modification Example) Next, an example applicable to any of Examples 1 to 4 will be described as a modification example.

[0166] <Modification Example 1> The relationship between the beam of the Aperiodic CSI-RS triggered for RLM / BFR and the beam used during LBT sensing may be defined. This relationship may be specified in the specification or set from the base station 10 to the terminal 20. Examples of this relationship are Examples 1 to 3 below.

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

[0168] Example 2: The beam of the Aperiodic CSI-RS triggered for RLM / BFR and the beam used during LBT sensing have the same direction but different widths. For example, the beam width of the Aperiodic CSI-RS is made 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 during LBT sensing have different directions and different widths. For example, the space defined by the direction and width of the Aperiodic CSI-RS beam is made to be included in the space defined by the direction and width of the beam used for LBT sensing corresponding to the COT.

[0170] <Modification Example 2> Each of the Examples in Examples 1 to 4 may be applied when the base station 10 and the terminal 20 use frequencies in a specific frequency range. The specific frequency range may be 52.6 to 71 GHz.

[0171] <Modification Example 3> Each of the Examples in Examples 1 to 4 may be applied when specific conditions are satisfied. For example, whether the operation of using Aperiodic CSI-RS for RLM / BFR can be carried out may be determined by 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 the LBT operation is ON (or the band to be used is an unlicensed band), the base station 10 may transmit the DCI described in Example 2 to cause the terminal 20 to use Aperiodic CSI-RS for RLM / BFR.

[0173] Also, when the LBT operation is ON (or the band to be used is an unlicensed band), the base station 10 may perform the RRC setting described in Example 3 to cause the terminal 20 to use Aperiodic CSI-RS for RLM / BFR.

[0174] <Modification Example 4> Example 2 (DCI extension) and Example 3 (RRC extension) may be implemented in combination. The same applies to Example 4 corresponding to Example 2 (DCI extension) and Example 3 (RRC extension).

[0175] <Modification Example 5> Regarding whether the terminal 20 uses each example described in Examples 1 to 4, settings / instructions / reports, etc. may be performed according to the following Examples 1 to 4.

[0176] Example 1: Perform setting to the terminal 20 by upper layer parameters (e.g., RRC, MAC CE).

[0177] Example 2: Report from terminal 20 to base station 10 based on UE capability.

[0178] Example 3: Specify in the specification.

[0179] Example 4: Determine based on the setting by upper layer parameters and the reported UE capability (combination of Example 1 and Example 2).

[0180] <Modification Example 6> Modification Example 6 is an example regarding UE capability. The UE capabilities shown in the following Examples 1 to 8 are defined, and any of the UE capabilities may be reported from terminal 20 to base station 10. This operation corresponds to the operation of S100 in FIG. 5.

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

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

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

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

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

[0186] UE capability indicating whether an existing DCI format using an existing RNTI, which is triggered by the terminal 20 for Aperiodic CSI-RS for RLM / BFR, is supported or not.

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

[0188] UE capability indicating whether the terminal 20 supports RRC configuration information for determining the purpose for which Aperiodic CSI-RS is used.

[0189] According to the technology related to the embodiment described above, a technology is provided that enables a terminal to appropriately perform fault detection and recovery in a wireless communication system.

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

[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 includes a transmission unit 110, a reception 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 operations according to the embodiment of the present invention can be executed, the functional classification and the names of the functional units may be anything. Also, the transmission unit 110 and the reception unit 120 may be collectively referred to as a communication unit.

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

[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 it out from the storage device as necessary.

[0194] The control unit 140 schedules the DL reception or UL transmission of the terminal 20 via the transmitting unit 110. Further, the control unit 140 includes a function of performing LBT. A functional unit related to signal transmission in the control unit 140 may be included in the transmitting unit 110, and a functional unit related to signal reception in the control unit 140 may be included in the receiving unit 120. Also, the transmitting unit 110 may be called a transmitter, and the receiving 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 includes 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 only an example. As long as the operations according to the embodiments of the present invention can be executed, the function classification and the names of the 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 transmitting unit 210 creates a transmission signal from the transmission data and wirelessly transmits the transmission signal. The receiving unit 220 wirelessly receives various signals and obtains signals of a higher layer from the received physical layer signals. Also, the receiving unit 220 has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL / UL / SL control signals, DCI by PDCCH, data by PDSCH, etc. transmitted from the base station 10. Further, for example, the transmitting unit 210 may transmit PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. to another terminal 20 as D2D communication, and the receiving unit 120 may receive PSCCH, PSSCH, PSDCH, or PSBCH, etc. from another terminal 20.

[0197] The setting unit 230 stores various setting information received from the base station 10 or another terminal by the receiving unit 220 in a storage device provided in the setting unit 230 and reads it out from the storage device as necessary. Also, the setting unit 230 stores preset setting information. The control unit 240 controls the terminal 20. Also, the control unit 240 includes a function of performing LBT.

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

[0199] <Configuration related to Embodiments 2 and 4> (Item 1) A receiving unit that receives downlink control information from a base station, A control unit that performs measurements for wireless link monitoring or beam failure recovery using an aperiodic reference signal received from the base station based on a trigger by the downlink control information And a terminal comprising the same. (Item 2) The downlink control information includes the purpose of an aperiodic reference signal. Based on the purpose, the control unit determines that the aperiodic reference signal is a reference signal used for radio link monitoring or beam failure recovery. The terminal according to claim 1. (Item 3) Based on the format of the downlink control information, the control unit determines that the aperiodic reference signal is a reference signal used for radio link monitoring or beam failure recovery. The terminal according to claim 1 or 2. (Item 4) Based on the RNTI used for scrambling the downlink control information, the control unit determines that the aperiodic reference signal is a reference signal used for radio link monitoring or beam failure recovery. The terminal according to any one of claims 1 to 3. (Item 5) A transmitting unit that transmits downlink control information to a terminal, Based on a trigger by the downlink control information, the transmitting unit transmits an aperiodic reference signal, and in the terminal, measurements for radio link monitoring or beam failure recovery are performed using the aperiodic reference signal. Base station. (Item 6) Receiving downlink control information from a base station, Based on a trigger by the downlink control information, performing measurements for radio link monitoring or beam failure recovery using an aperiodic reference signal received from the base station A measurement method in a terminal, comprising:

[0200] According to any of the above configurations, a technique is provided that enables a terminal to appropriately perform fault detection and recovery in a wireless communication system. According to Item 2, the purpose can be clearly grasped. According to Items 3 and 4, even if the purpose is not explicitly included, the terminal can grasp the purpose.

[0201] <Configuration Regarding Embodiments 3 and 4> (Item 1) A receiving unit that receives configuration information of an aperiodic reference signal used for radio link monitoring or beam failure recovery from a base station, A control unit that performs measurements for radio link monitoring or beam failure recovery using the aperiodic reference signal based on a trigger by downlink control information received from the base station A terminal comprising the same. (Item 2) A receiving unit that receives configuration information including the purpose of an aperiodic reference signal from a base station, A control unit that performs measurements for radio link monitoring or beam failure recovery using the aperiodic reference signal specified by the configuration information according to the purpose based on a trigger by downlink control information received from the base station A terminal comprising the same. (Item 3) The purpose is included in each triggering state in the configuration information The terminal according to Item 2. (Item 4) The configuration information has a list of triggering states, All triggering states in the list are information specifying an aperiodic reference signal for radio link monitoring or beam failure recovery, or Some of all triggering states in the list are information specifying an aperiodic reference signal for radio link monitoring or beam failure recovery The terminal according to Item 2 or Item 3. (Item 5) A base station comprising a transmitting unit that transmits configuration information including the purpose of an aperiodic reference signal to a terminal, The transmitting unit transmits downlink control information, and in the terminal, measurements for radio link monitoring or beam failure recovery are performed using the aperiodic reference signal specified by the configuration information according to the purpose based on a trigger by the downlink control information A base station. (Item 6) Receiving, from a base station, configuration information including an objective of an aperiodic reference signal; Performing, based on a trigger by downlink control information received from the base station, measurements for radio link monitoring or beam failure recovery by using the aperiodic reference signal specified by the configuration information according to the objective; A measurement method performed by a terminal, comprising the above.

[0202] According to any of the above configurations, a technique is provided that enables a terminal to appropriately perform failure detection and recovery in a wireless communication system. According to Item 3, an objective can be set in each triggering state. According to Item 4, variations of a triggering state list can be realized.

[0203] (Hardware Configuration) The block diagrams (FIGS. 22 and 23) used in the description of the above embodiment show blocks of functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Also, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized by using one physically or logically combined device, or two or more physically or logically separated devices may be directly or indirectly (e.g., using wired, wireless, etc.) connected and realized by using these multiple devices. The functional block may be realized by combining software with the above one device or the above multiple devices.

[0204] Functions include, but are not limited to, judgment, decision-making, determination, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection determination, establishment, comparison, assumption, expectation, presumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), assigning, etc. For example, a functional block (component) that enables transmission is called a transmitting unit or a transmitter. As described above, the implementation method is not particularly limited.

[0205] For example, the base station 10, the terminal 20, etc. in an embodiment of the present disclosure may function as a computer that performs the processing of the wireless communication method of the present disclosure. FIG. 24 is a diagram showing an example of the hardware configuration of the base station 10 and the terminal 20 according to an embodiment of the present disclosure. Physically, the above-described base station 10 and terminal 20 may be 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, and the like.

[0206] Note that in the following description, the term "device" can be read 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 each device shown in the figure, or may be configured without including some devices.

[0207] Each function in the base station 10 and the terminal 20 is realized by causing the processor 1001 to perform calculations by loading a predetermined software (program) onto hardware such as the processor 1001 and the storage device 1002, and controlling the communication by the communication device 1004, or controlling at least one of reading and writing data in the storage device 1002 and the auxiliary storage device 1003.

[0208] The processor 1001 controls the entire computer by operating, for example, an operating system. The processor 1001 may be composed of a central processing unit (CPU: Central Processing Unit) including an interface with peripheral devices, a control device, an arithmetic device, registers, and the like. For example, the above-described control unit 140, control unit 240, etc. may be realized by the processor 1001.

[0209] Also, the processor 1001 reads a program (program code), software module, data, etc. from at least one of the auxiliary storage device 1003 and the communication device 1004 into the storage device 1002, and executes various processes according to these. As the program, a program for causing a computer to execute at least a part of the operations described in the above embodiments is used. For example, the control unit 140 of the base station 10 shown in FIG. 22 may be stored in the storage device 1002 and realized by a control program operating on the processor 1001. Also, for example, the control unit 240 of the terminal 20 shown in FIG. 23 may be stored in the storage device 1002 and realized by a control program operating on the processor 1001. Although it has been described that the above various processes are executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be mounted by one or more chips. Note that 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 constituted by at least one of, for example, ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), etc. The storage device 1002 may be referred to as a register, a cache, a main memory (main storage device), etc. The storage device 1002 can store a program (program code), a software module, etc. executable for implementing the 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 constituted by at least one of, for example, optical discs such as CD-ROM (Compact Disc ROM), hard disk drives, flexible disks, magneto-optical disks (e.g., compact discs, digital versatile discs, Blu-ray (registered trademark) discs), smart cards, flash memories (e.g., cards, sticks, key drives), floppy (registered trademark) disks, magnetic strips, etc. The above-described storage medium may be, for example, a database, a server, or other appropriate medium including at least one of the storage device 1002 and the auxiliary storage device 1003.

[0212] The communication device 1004 is hardware (a transceiver device) for performing communication between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. in order to implement at least one of frequency-division duplexing (FDD) and time-division duplexing (TDD). For example, a transceiver antenna, an amplifier section, a transceiver section, a transmission line interface, etc. may be implemented by the communication device 1004. The transceiver section may be physically or logically separated into a transmission section and a reception section.

[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 receives an external input. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that performs an output to the outside. Note that the input device 1005 and the output device 1006 may have an integrated configuration (e.g., a touch panel).

[0214] Also, 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 for each device.

[0215] In addition, 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), and a field programmable gate array (FPGA). 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 hardware components.

[0216] (Supplement of the Embodiment) The embodiments of the present invention have been described above. However, the disclosed invention is not limited to such embodiments, and those skilled in the art will understand various modifications, corrections, alternatives, substitutions, etc. Although specific numerical examples have been used for the purpose of facilitating the understanding of the invention, unless otherwise specified, these numerical values are merely examples, and any appropriate values may be used. The classification of items in the above description is not essential to the present invention, and the matters described in two or more items may be used in combination as needed, or the matters described in one item may be applied to the 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 components. The operations of a plurality of functional units may be physically performed by one component, or the operation of one functional unit may be physically performed by a plurality of components. Regarding the processing procedures described in the embodiments, the order of processing may be changed as long as there is no contradiction. For the sake of convenience in explaining the processing, the base station 10 and the terminal 20 have been described using a functional block diagram, but such devices may be implemented in hardware, software, or a combination thereof. The software operated by the processor included in the base station 10 according to the embodiment of the present invention and the software operated by the processor included in the terminal 20 according to the embodiment of the present invention may be stored in a random access memory (RAM), a flash memory, a read-only memory (ROM), an EPROM, an EEPROM, a register, a hard disk drive (HDD), a removable disk, a CD-ROM, a database, a server, or any other appropriate storage medium, respectively.

[0217] In addition, the notification of information is not limited to the aspects / embodiments described in the present disclosure, and other methods may be used. For example, the notification of information may be implemented by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, notification information (MIB (Master Information Block), SIB (System Information Block)), other signals or combinations thereof. Also, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC connection setup (RRC Connection Setup) message, an RRC connection reconfiguration (RRC Connection Reconfiguration) message, etc.

[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), other suitable systems, and next-generation systems extended based thereon. Also, 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 processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this specification may be rearranged as long as there is no contradiction. For example, for the methods described in this disclosure, the elements of various steps are presented using an exemplary order and are not limited to the specific order presented.

[0220] The specific operations assumed to be performed by the base station 10 in this specification may, in some cases, be performed by its upper node. 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 can be performed by at least one of the base station 10 and other network nodes other than the base station 10 (for example, but not limited to, MME or S-GW, etc.). Although the case where there is one other network node other than the base station 10 is exemplified above, the other network node may be a combination of a plurality of other network nodes (for example, MME and S-GW).

[0221] The information or signals, etc. described in this disclosure can be output from an upper layer (or lower layer) to a lower layer (or upper layer). They may also be input and output via a plurality of network nodes.

[0222] The input and output information, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. The input and output information, etc. can be overwritten, updated, or appended. The output information, etc. may be deleted. The input information, etc. may be transmitted to other devices.

[0223] The determination in this disclosure may be made by a value represented by 1 bit (0 or 1), or by a Boolean value (true or false), or by a numerical comparison (for example, comparison with a predetermined value).

[0224] Software should be broadly construed to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc., whether called software, firmware, middleware, microcode, hardware description language, or by any other name.

[0225] Also, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), etc.) and wireless technologies (such as infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of the transmission medium.

[0226] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc., which may be referred to throughout the above description, may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0227] In addition, terms described in this disclosure and 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 referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0228] The terms "system" and "network" used in this disclosure are used interchangeably.

[0229] In addition, the information, parameters, etc. described in this disclosure may be represented using absolute values, relative values from a predetermined value, or using other corresponding information. For example, the radio resources may be indicated by an index.

[0230] The names used for the above-described parameters are not limiting in any way. Furthermore, the mathematical formulas, etc. using these parameters may be different from those explicitly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable names, the various names assigned to these various channels and information elements are not limiting in any way.

[0231] In this disclosure, terms such as "base station (BS: Base Station)", "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. The base station may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0232] A base station can accommodate one or more (e.g., three) cells. When the 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 provide 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 whole of the coverage area of at least one of the base station and the base station subsystem that provides communication services in this coverage.

[0233] In this disclosure, terms such as "mobile station (MS)", "user terminal", "user equipment (UE)", and "terminal" can 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 terms.

[0235] At least one of the base station and the mobile station may also be referred to as a transmitting device, a receiving device, a communication device, etc. Note that at least one of the base station and the mobile station may also 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.), a moving body that moves without a driver (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanoid or non-humanoid). Note that at least one of the base station and the mobile station also includes devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0236] Also, the base station in the present disclosure may be replaced by a terminal. For example, for a configuration in which communication between the base station and the terminal is replaced by communication between a plurality of terminals 20 (which may be referred to as, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.), each aspect / embodiment of the present disclosure may be applied. In this case, the functions of the above-described base station 10 may be configured to be functions of the terminal 20. Also, terms such as "uplink" and "downlink" may be replaced with terms corresponding to communication between terminals (for example, "side"). For example, the uplink channel, downlink channel, etc. may be replaced with side channels.

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

[0238] As used in this disclosure, the terms "determining" and "deciding" may encompass a wide variety of actions. "Determining" and "deciding" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up (e.g., searching in a table, database, or other data structure), ascertaining, and considering something as having been "determined" or "decided". Also, "determining" and "deciding" may include considering something as having been "determined" or "decided" after receiving (e.g., receiving information), transmitting (e.g., transmitting information), inputting, outputting, accessing (e.g., accessing data in a memory), etc. Further, "determining" and "deciding" may include considering something as having been "determined" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. That is, "determining" and "deciding" may include considering that some action has been "determined" or "decided". Also, "determining (deciding)" may be read as "assuming", "expecting", "considering", etc.

[0239] The terms "connected" or "coupled" and any variations thereof mean any direct or indirect connection or coupling between two or more elements, and can 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 can be physical, logical, or a combination thereof. For example, "connected" may be read as "accessed". As used in this disclosure, two elements can be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, and also using, as some non-limiting and non-exhaustive examples, electromagnetic energy having wavelengths in the radio frequency region, microwave region, and optical (both visible and invisible) region.

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

[0241] As used in this disclosure, the description "based on" does not mean "based only on" unless otherwise specified. In other words, the description "based on" means both "based only on" and "based at least on".

[0242] Any reference to an element using designations such as "first", "second", etc. used in this disclosure does not generally limit the quantity or order of those elements. These designations can be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a second element does not mean that only two elements can be employed, or that the first element must precede the second element in any form.

[0243] In the configuration of each of the above devices, the "means" can be replaced with "section", "circuit", "device", etc.

[0244] In the present disclosure, when terms such as "include", "including" and their variants are used, these terms are intended to be inclusive, similar to the term "comprising". Further, the term "or" used in the present disclosure is not intended to be an exclusive disjunction.

[0245] A wireless 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. The subframe may have a fixed time length (e.g., 1 ms) independent of numerology.

[0246] Numerology may be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. Numerology may indicate, for example, at least one of subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, wireless frame configuration, specific filtering processing performed by a transceiver in the frequency domain, specific windowing processing performed by a transceiver in the time domain, etc.

[0247] A slot may be composed of one or more symbols (such as OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain. A slot may be a time unit based on numerology.

[0248] The slot may include a plurality of mini-slots. Each mini-slot may be composed of one or more symbols in the time domain. Also, the mini-slot may be called a sub-slot. The mini-slot may be composed of a smaller number of symbols than the slot. The PDSCH (or PUSCH) transmitted in a time unit larger than the mini-slot may be called PDSCH (or PUSCH) mapping type A. The PDSCH (or PUSCH) transmitted using the mini-slot may be called PDSCH (or PUSCH) mapping type B.

[0249] The radio frame, sub-frame, slot, mini-slot, and symbol all represent time units when transmitting signals. Different names corresponding to each of the radio frame, sub-frame, slot, mini-slot, and symbol may be used.

[0250] For example, one sub-frame may be called a Transmission Time Interval (TTI), a plurality of consecutive sub-frames may be called a TTI, or one slot or one mini-slot may be called a TTI. That is, at least one of the sub-frame and the TTI may be the sub-frame (1 ms) in the existing LTE, or may be a period shorter than 1 ms (for example, 1 - 13 symbols), or may be a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, a mini-slot, etc. instead of a sub-frame. Also, one slot may be called a unit time. The unit time may vary for each cell according to the numerology.

[0251] Here, the TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, the base station performs scheduling to allocate radio resources (such as the frequency bandwidth and transmission power that can be used in each terminal 20) to each terminal 20 in TTI units. Note that the definition of the TTI is not limited to this.

[0252] The TTI may be a transmission time unit such as a channel-coded data packet (transport block), code block, codeword, etc., or may be a processing unit such as scheduling and link adaptation. When the TTI is given, the time interval (e.g., number of symbols) in which a transport block, code block, codeword, etc. are actually mapped may be shorter than the TTI.

[0253] In addition, when one slot or one mini-slot is called a TTI, one or more TTIs (i.e., one or more slots or one or more mini-slots) may be the minimum time unit for scheduling. Also, the number of slots (number of mini-slots) constituting the minimum time unit for the 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), normal TTI, long TTI, normal subframe, normal subframe, long subframe, slot, etc. A TTI shorter than the normal TTI may be called a shortened TTI, short TTI, partial TTI (partial or fractional TTI), shortened subframe, short subframe, mini-slot, sub-slot, slot, etc.

[0255] In addition, a long TTI (e.g., normal TTI, subframe, etc.) may be read as a TTI having a time length exceeding 1 ms, and a short TTI (e.g., shortened TTI, etc.) may be read as a TTI having a TTI length less than that of the long TTI and equal to or more than 1 ms.

[0256] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and in the frequency domain, it may include one or a plurality of consecutive subcarriers. The number of subcarriers included in the RB may be the same regardless of the numerology, for example, it may be 12. The number of subcarriers included in the RB may be determined based on the numerology.

[0257] Also, the time domain of the RB may include one or more symbols, and may have the length of 1 slot, 1 mini-slot, 1 sub-frame, or 1 TTI. 1 TTI, 1 sub-frame, etc. may each be composed of one or more resource blocks.

[0258] Note that one or more RBs may be referred to as physical resource blocks (PRBs), sub-carrier groups (SCGs), resource element groups (REGs), PRB pairs, RB pairs, etc.

[0259] Also, a resource block may be composed of one or more resource elements (REs). For example, 1 RE may be a radio resource area of 1 sub-carrier and 1 symbol.

[0260] A bandwidth part (BWP) (which may also be called a partial bandwidth, etc.) may represent a subset of consecutive common resource blocks for a certain numerology in a certain carrier. Here, the common RB may be specified by the index of the RB based on the common reference point of the carrier. A PRB is defined in a certain BWP and may be 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 set within one carrier for a UE.

[0262] At least one of the set BWPs may be active, and the UE may not be assumed to transmit and receive a predetermined signal / channel outside the active BWP. Note that "cell", "carrier", etc. in the present disclosure may be read as "BWP".

[0263] The structures such as the above-described radio frames, sub-frames, slots, mini-slots, and symbols are merely illustrative. For example, the number of sub-frames included in a radio frame, the number of slots per sub-frame or radio frame, the number of mini-slots included in a slot, the number of symbols and RBs included in a slot or mini-slot, the number of sub-carriers included in an RB, and the number of symbols within a TTI, symbol length, cyclic prefix (CP) length, etc. can be variously changed.

[0264] In the present disclosure, for example, when articles are added by translation like a, an, and the in English, the present 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 that "A and B are different from each other". Note that the term may also mean that "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 the present disclosure may be used alone, in combination, or switched and used during execution. Also, the notification of predetermined information (for example, the notification of "being X") is not limited to being explicitly performed, and may be performed implicitly (for example, without performing the notification of the predetermined information).

[0267] As described in detail above regarding the present disclosure, 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 as modified and changed aspects without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is for the purpose of illustrative explanation and does not have any restrictive meaning with respect to the present disclosure.

Description of Reference Numerals

[0268] 10 Base Station 110 Transmitter 120 Receiver 130 Setting Unit 140 Control Unit 20 Terminal 210 Transmitter 220 Receiver 230 Setting Unit 240 Control Unit 1001 Processor 1002 Memory Device 1003 Auxiliary Memory Device 1004 Communication Device 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 by a non-periodic reference signal received from the base station based on a format of the downlink control information; A terminal comprising:

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. The terminal according to claim 1.

3. 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 by a non-periodic reference signal received from the base station based on the RNTI of the downlink control information; A terminal comprising:

4. A transmitter for transmitting downlink control information to a terminal, The transmitting unit transmits an aperiodic reference signal based on a format of the downlink control information, and the terminal performs measurement for radio link monitoring or beam failure recovery by using the aperiodic reference signal. Base station.

5. 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 format of the downlink control information; A measurement method in a terminal comprising:

Images