Terminal, wireless communication method, base station and system

Abstract

A terminal according to one aspect of the present disclosure has: a control unit that decides one operation from a plurality of operations including a first operation of receiving a plurality of first reference signals among a plurality of reference signals and a second operation of receiving a plurality of second reference signals among the plurality of reference signals; and a receiving unit that receives at least one of the plurality of first reference signals and the plurality of second reference signals in accordance with the one operation. The number of the plurality of second reference signals is less than the number of the plurality of first reference signals. According to one aspect of the present disclosure, coverage can be improved by taking overhead into account.

Description

[Technical Field]

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

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

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

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

[0005] In future wireless communication systems (e.g., NR), improvements in coverage are being considered.

[0006] However, narrowing / increasing the number of beams to improve coverage may increase overhead and reduce communication throughput.

[0007] Therefore, the present disclosure provides a terminal and a wireless communication method that can improve coverage while taking overhead into consideration. 、 base station and systems One of the aims is to provide [Means for solving the problem]

[0008] A terminal according to an embodiment of the present disclosure may select a plurality of first reference signals from among a plurality of reference signals. , when performing event-based beam reporting Receive a receiver for receiving the plurality of first reference signals; a plurality of operations including a first operation and a second operation of receiving a plurality of second reference signals from the plurality of reference signals; , based on the radio resource control information element transmitted from the base station a control unit that determines one operation; The receiving unit comprises: receiving at least one of the plurality of first reference signals and the plurality of second reference signals according to the one operation; Faith , the plurality of first reference signals include the plurality of second reference signals; The number of the plurality of second reference signals is less than the number of the plurality of first reference signals. [Effects of the Invention]

[0009] According to one aspect of the present disclosure, coverage can be improved by taking overhead into account. [Brief explanation of the drawings]

[0010] [Figure 1] 1A and 1B show an example of beams and coverage. [Figure 2] 2A and 2B show an example of an SSB multiplexing method. [Figure 3] 3A and 3B show an example of a group multiplexing method. [Figure 4] FIG. 4 shows an example of a receiving operation A. [Figure 5] FIG. 5 shows an example of the receiving operation B. [Figure 6] FIG. 6 shows an example of frequency hopping of the measurement target. [Figure 7] 7A and 7B show an example of the period of an SSB. [Figure 8] FIG. 8 shows an example of a beam within a cell. [Figure 9] FIG. 9 shows an example of selection method 1. [Figure 10] 10A and 10B show an example of selection method 2. [Figure 11] 11A and 11B show another example of selection method 2. [Figure 12] 12A and 12B show an example of measurements based on operations B and A. [Figure 13] 13A and 13B show an example of reception based on actions B and A. [Figure 14] FIG. 14 shows an example of an instruction based on the value of a particular field. [Figure 15] 15A and 15B show an example of measurement targets based on groups A and B. [Figure 16] 16A and 16B show an example of reception based on groups A and B. FIG. [Figure 17] FIG. 17 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. [Figure 18] FIG. 18 is a diagram illustrating an example of the configuration of a base station according to an embodiment. [Figure 19] FIG. 19 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. [Figure 20] FIG. 20 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. [Figure 21] FIG. 21 is a diagram illustrating an example of a vehicle according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] (TCI, spatial relations, QCL) In NR, it is being considered to control the reception processing (e.g., at least one of reception, demapping, demodulation, and decoding) and transmission processing (e.g., at least one of transmission, mapping, precoding, modulation, and encoding) in the UE of at least one of a signal and a channel (referred to as signal / channel) based on the transmission configuration indication state (TCI state).

[0012] The TCI state may represent that which is applied to a downlink signal / channel, and the equivalent of the TCI state which is applied to an uplink signal / channel may be expressed as a spatial relation.

[0013] The TCI state is information about the quasi-co-location (QCL) of signals / channels, and may also be called spatial reception parameters, spatial relation information, etc. The TCI state may be configured in the UE for each channel or signal.

[0014] A QCL is an index that indicates the statistical properties of a signal / channel. For example, if a signal / channel has a QCL relationship with another signal / channel, it may mean that it can be assumed that at least one of the Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (e.g., spatial Rx parameter) is the same between these different signals / channels (i.e., they are QCLs with respect to at least one of these).

[0015] The spatial reception parameters may correspond to a reception beam (e.g., a reception analog beam) of the UE, and the beam may be determined based on a spatial QCL. A QCL (or at least one element of a QCL) in the present disclosure may be replaced with an sQCL (spatial QCL).

[0016] A plurality of types (QCL types) of QCLs may be defined. For example, four QCL types A and B may be provided, each having different parameters (or parameter sets) that can be assumed to be the same. The parameters (which may also be referred to as QCL parameters) are listed below: QCL Type A (QCL-A): Doppler shift, Doppler spread, mean delay and delay spread, QCL Type B (QCL-B): Doppler shift and Doppler spread, QCL Type C (QCL-C): Doppler shift and mean delay, · QCL Type D (QCL-D): Spatial reception parameters.

[0017] The assumption by a UE that a Control Resource Set (CORESET), channel, or reference signal has a specific QCL (e.g., QCL type D) relationship with another CORESET, channel, or reference signal may be referred to as a QCL assumption.

[0018] The UE may determine at least one of a transmit beam (Tx beam) and a receive beam (Rx beam) for a signal / channel based on the TCI condition or QCL assumption of the signal / channel.

[0019] The TCI state may be, for example, information about the QCL between the target channel (in other words, the Reference Signal (RS) for the channel) and another signal (e.g., another RS). The TCI state may be set (indicated) by higher layer signaling, physical layer signaling, or a combination thereof.

[0020] The physical layer signaling may be, for example, Downlink Control Information (DCI).

[0021] The channel for which the TCI state or spatial relationship is set (specified) may be, for example, at least one of a downlink shared channel (Physical Downlink Shared Channel (PDSCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), an uplink shared channel (Physical Uplink Shared Channel (PUSCH)), and an uplink control channel (Physical Uplink Control Channel (PUCCH)).

[0022] Furthermore, the RS that has a QCL relationship with the channel may be, for example, at least one of a Synchronization Signal Block (SSB), a Channel State Information Reference Signal (CSI-RS), a Sounding Reference Signal (SRS), a CSI-RS for tracking (also called a Tracking Reference Signal (TRS)), and a QCL detection reference signal (also called a QRS).

[0023] An SSB is a signal block that includes at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). An SSB may also be referred to as an SS / PBCH block.

[0024] An RS of QCL type X in a TCI state may refer to an RS that has a relationship of QCL type X with (the DMRS of) a certain channel / signal, and this RS may be called a QCL source of QCL type X in the TCI state.

[0025] (Initial Access Procedures) In the initial access procedure, the UE (RRC_IDLE mode) receives the SS / PBCH block (SSB), transmits Msg.1 (PRACH / random access preamble / preamble), receives Msg.2 (PDCCH, PDSCH including random access response (RAR)), transmits Msg.3 (PUSCH scheduled by RAR UL grant), and receives Msg.4 (PDCCH, PDSCH including UE contention resolution identity). After that, when the base station (network) transmits an ACK for Msg.4 from the UE, an RRC connection is established (RRC_CONNECTED mode).

[0026] SSB reception includes PSS detection, SSS detection, PBCH-DMRS detection, and PBCH reception. PSS detection detects part of the physical cell ID (PCI), detects (synchronizes) OFDM symbol timing, and performs (coarse) frequency synchronization. SSS detection includes detecting the physical cell ID. PBCH-DMRS detection includes detecting (part of) the SSB index within a half radio frame (5 ms). PBCH reception includes detecting the system frame number (SFN) and radio frame timing (SSB index), receiving configuration information for receiving remaining minimum system information (RMSI, SIB1), and recognizing whether the UE can camp on that cell (carrier).

[0027] SSB has a bandwidth of 20 RB and a time of 4 symbols. The transmission period of SSB can be set to {5, 10, 20, 40, 80, 160} ms. In the half frame, multiple symbol positions of SSB are specified based on the frequency range (FR1, FR2).

[0028] The PBCH has a payload of 56 bits. N repetitions of the PBCH are transmitted within a period of 80 ms, where N depends on the SSB transmission period.

[0029] The system information consists of the MIB, RMSI (SIB1), and other system information (OSI) carried by the PBCH. SIB1 contains information for RACH configuration and RACH procedures. The time / frequency resource relationship between the SSB and the PDCCH monitoring resource for SIB1 is configured by the PBCH.

[0030] A base station using beam correspondence transmits multiple SSBs using multiple beams in each SSB transmission period. The multiple SSBs have multiple SSB indices. When a UE detects an SSB, it transmits a PRACH in the RACH occasion associated with that SSB index and receives an RAR in the RAR window.

[0031] (Beam and Coverage) In high-frequency bands, if beamforming is not applied to synchronization signals / reference signals, coverage will be narrow, making it difficult for UEs to find base stations. On the other hand, if beamforming is applied to synchronization signals / reference signals to ensure coverage, a strong signal will reach a specific direction, but the signal will be even more difficult to reach in other directions (Figure 1A). If the base station does not know the direction of the UE before connecting, it is impossible to transmit synchronization signals / reference signals using beams pointing only in the appropriate direction. One possible method is for the base station to transmit multiple synchronization signals / reference signals, each with a beam pointing in a different direction, and for the UE to recognize which beam it has found. Using thin (narrow) beams for coverage requires transmitting many synchronization signals / reference signals, which increases overhead and may reduce frequency utilization efficiency.

[0032] In order to reduce the number of beams (synchronization signals / reference signals) and reduce overhead, using a thick (wide) beam results in a narrower coverage area (Figure 1B).

[0033] In future wireless communication systems (e.g., 6G), it is expected that the use of frequency bands such as millimeter waves and terahertz waves will become more widespread. It is conceivable that communication services will be provided by constructing cell areas / coverage using multiple narrow beams.

[0034] It is possible to expand the coverage area by using the existing FR2, or to use a higher frequency band than the existing FR2. To achieve this, it is desirable to improve beam management in addition to multi-TRP, reconfigurable intelligent surface (RIS), etc.

[0035] In current 5G NR, the maximum number of synchronization signal blocks (SSBs) is 64. Because it is necessary to cover the cell area (surface) using a maximum of 64 beams, it is difficult to use narrow beams. To use a large number of narrow beams, the following beam management methods 1 and 2 can be considered.

[0036] [Beam management method 1] Use more than 64 SSBs (the maximum number of SSBs exceeds 64). Simply increasing the number of SSBs may increase SSB overhead / initial access delay.

[0037] [Beam management method 2] Use up to 64 SSBs (the maximum number of SSBs is 64). Reduce the area (surface) covered by one cell / sector. Inter-cell / sector interference and fast / frequent handover between cells / sectors may become problems.

[0038] Therefore, the present inventors came up with a method for reducing overhead / initial access delay.

[0039] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. Wireless communication methods according to the embodiments may be applied independently or in combination.

[0040] In the present disclosure, "A / B" and "at least one of A and B" may be interpreted interchangeably. Also, in the present disclosure, "A / B / C" may mean "at least one of A, B, and C."

[0041] In the present disclosure, terms such as activate, deactivate, indicate (or indicate), select, configure, update, and determine may be read interchangeably. In the present disclosure, terms such as support, control, controllable, operate, and operate may be read interchangeably.

[0042] In the present disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher layer parameters, information elements (IEs), configurations, etc. may be interchangeable. In the present disclosure, Medium Access Control (MAC) control elements (CEs), update commands, activation / deactivation commands, etc. may be interchangeable.

[0043] In the present disclosure, higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, and the like, or a combination thereof.

[0044] In the present disclosure, MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. Broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0045] In the present disclosure, physical layer signaling may be, for example, Downlink Control Information (DCI), Uplink Control Information (UCI), and the like.

[0046] In this disclosure, the terms index, identifier (ID), indicator, resource ID, etc. may be interchangeable. In this disclosure, the terms sequence, list, set, group, cluster, subset, etc. may be interchangeable.

[0047] In this disclosure, the terms panel, UE panel, panel group, beam, beam group, precoder, Uplink (UL) transmitting entity, Transmission / Reception Point (TRP), base station, Spatial Relation Information (SRI), spatial relation, SRS Resource Indicator (SRI), Control Resource Set (CORESET), Physical Downlink Shared Channel (PDSCH), Codeword (CW), Transport Block (TB), Reference Signal (RS), antenna port (e.g., Demodulation Reference Signal (DMRS) port), antenna port group (e.g., DMRS port group), group (e.g., spatial relation group, Code Division Multiplexing (CDM) group, reference signal group, CORESET group, Physical Uplink Control Channel (PUCCH) group, PUCCH resource group), resource (e.g., reference signal resource, SRS resource), resource set (e.g., reference signal resource set), CORESET pool, downlink Transmission Configuration Indication state (TCI state) (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, Quasi-Co-Location (QCL), QCL assumption, etc. may be read as interchangeable.

[0048] In the present disclosure, the SSB / CSI-RS index / indicator and the beam index may be read interchangeably.

[0049] (Wireless communication method) In each embodiment, SSB, CSI-RS, DL-RS, beam, and TCI state may be interchangeable.

[0050] In each embodiment, the terms period, frame, subframe, slot, and symbol may be interchangeable.

[0051] In each embodiment, the terms group, set, SSB / CSI-RS to be measured, specific SSB / CSI-RS, and specific reference signal (RS) may be interchangeable.

[0052] In each embodiment, the number of SSB / CSI-RS may be different from the number of existing SSB / CSI-RS, may be greater than the number of existing SSB / CSI-RS, or may be greater than 64.

[0053] First Embodiment This embodiment relates to an SSB configuration.

[0054] <<Aspect 1-1>> This aspect relates to multiplexing of multiple SSBs. Multiple SSBs may be transmitted periodically. Different beams may be applied to the multiple SSBs.

[0055] [Multiple method 1a] Multiple SSBs may be time division multiplexed (TDM).

[0056] As shown in the example above in FIG. 2A, SSB#0 to SSB#192 may be TDM'd.

[0057] Although the examples in the drawings of each embodiment show parts where the time intervals between multiple SSB / CSI-RS are constant and parts where they are not constant, the time intervals between multiple SSB / CSI-RS are not limited to these examples. The time intervals between multiple SSB / CSI-RS may or may not be constant.

[0058] [Multiple method 2a] Multiple SSBs may be multiplexed using TDM / frequency division multiplexing (FDM) / code division multiplexing (CDM) / space division multiplexing (SDM).

[0059] As shown in the example at the bottom of Figure 2B, SSBs #0 to #63 may be TDM'd, SSBs #64 to #127 may be TDM'd, and SSBs #128 to #191 may be TDM'd. SSBs #0 to #63, SSBs #64 to #127, and SSBs #128 to #191 may be FDM'd. Here, FDM / CDM / SDM may be used instead of FDM.

[0060] The multiplexing method 2a has a shorter cycle and higher resource utilization efficiency than the multiplexing method 1a.

[0061] The periodicity of all SSB / CSI-RS may be the same as or different from the periodicity of SSB / CSI-RS specified in existing specifications.

[0062] Multiple SSBs may be grouped. SSBs included in different groups may have the same index. In this case, the SSBs may be identified / distinguished by the group index and the SSB index. SSBs included in different groups may have different indexes. In this case, the SSBs may be identified / distinguished by the SSB index.

[0063] [Multiple method 1b] Multiple TDM SSBs may be grouped together and given group indices in ascending time order.

[0064] As shown in the example of Figure 3A, groups (SSB groups) #0, #1, and #2 may each include TDM SSBs #0 through #63. Groups #0, #1, and #2 may be TDMed. Groups #0, #1, and #2 may include different SSBs. For example, group #1 may include TDM SSBs #64 through #127, and group #2 may include TDM SSBs #128 through #191.

[0065] In the examples of the drawings of each embodiment, the time intervals between the multiple groups are constant, but the time intervals between the multiple groups are not limited to these examples. The time intervals between the multiple groups may or may not be constant.

[0066] [Multiple method 2b] Multiple SSBs that have been subjected to TDM / FDM / CDM / SDM may be grouped. When multiple groups are FDM-modulated, group indices may be assigned in ascending order of frequency or in descending order of frequency.

[0067] As shown in the example of Figure 3B, groups #0, #1, and #2 may each include TDM SSBs #0 to #63. Groups #0, #1, and #2 may be FDM-based. Here, FDM / CDM / SDM may be used instead of FDM. Groups #0, #1, and #2 may include different SSBs. For example, group #1 may include TDM SSBs #64 to #127, and group #2 may include TDM SSBs #128 to #191.

[0068] The period of the group may be the same as or different from the period of SSB / CSI-RS defined in existing specifications.

[0069] <<Aspect 1-2>> This aspect relates to SSB reception / measurement / detection operations.

[0070] [Aspect 1-2-1] A UE may receive / measure / detect multiple SSBs in the same symbol.

[0071] For example, a UE may be capable of using multiple receiving panels to simultaneously receive / measure / detect RSs of different DL beams using the multiple panels (and has reported support for this operation through UE capability signaling).

[0072] [[Reception Action A]] This UE may receive, measure, and detect SSBs only during a certain period (e.g., period #1), and not receive, measure, or detect SSBs during other periods (e.g., periods #2 and #3) (Fig. 4). This operation reduces the power consumption required for SSB reception, measurement, and detection.

[0073] According to the scheduling restriction specified in the existing specifications, a PDSCH using a QCL type D different from that of the SSB / CSI-RS cannot be scheduled in the same symbol as the SSB / CSI-RS. Due to this restriction, a PDSCH cannot be scheduled in a symbol that overlaps with an SSB other than an SSB using the same beam. In reception operation A, the specifications may specify that there is no scheduling restriction in period #2 / #3. In this case, the network can schedule a PDSCH in period #2 and #3 without worrying about overlapping with the SSB in the time domain (same symbol), thereby improving throughput / spectral efficiency. The periods in which a UE receives / measures / detects SSBs and the periods in which it does not receive / measure / detect SSBs may be specified in the specifications or may be configured by higher layer signaling.

[0074] [[Reception Action B]] The UE may receive / measure / detect SSBs during all periods during which SSBs are transmitted (e.g., periods #1 to #3) (Fig. 5). The UE may not receive / measure / detect SSBs during some periods (e.g., periods #2 and #3).

[0075] This operation can improve the accuracy of SSB reception / measurement / detection compared to reception operation A. Compared to aspect 1-1, the base station can reduce the delay required for receiving / measuring / detecting all SSBs.

[0076] [Aspect 1-2-2] The specification may stipulate that the UE does not receive / measure / detect multiple SSBs in the same symbol.

[0077] For example, a UE that has multiple receiving panels and does not support the operation of simultaneously receiving / measuring / detecting RSs of different DL beams using the multiple panels (does not report support for this operation through UE capability signaling) may be specified as not performing this operation.

[0078] This UE may receive / measure / detect SSBs of group #0 in period #1, receive / measure / detect SSBs of group #1 in period #2, and receive / measure / detect SSBs of group #2 in period #3 (it may also perform frequency hopping for the SSB group being measured).

[0079] UEs (including Rel. 15 / 16 UEs) that cannot receive different QCL Type D DL RSs in the same symbol can receive, measure, and detect SSBs using a single QCL Type D RS in a given symbol, just as in Rel. 15, even if the SSBs are FDM / CDM / SDM-encoded. This simplifies UE operation. In the existing specifications, due to the scheduling restrictions mentioned above, PDSCH cannot be scheduled in the same symbol as an SSB, resulting in inefficient use of that symbol. However, by FDM / CDM / SDM-encode another SSB in that symbol, the symbol can be used more efficiently.

[0080] The UE may hop the frequency / code / space of the SSB / group to be measured for each period / frame / subframe / slot / symbol. The correspondence between the measurement period and the SSB / group (hopping method) may be specified in the specification, configured by higher layer signaling, or may depend on the UE implementation.

[0081] A formula / function for determining the group / SSB index for each period / frame / subframe / slot / symbol may be specified in the specification. The group / SSB index may be a function of the period / frame / subframe / slot / symbol index.

[0082] The index of the SSB / group to be measured may be changed for each period / frame / subframe / slot / symbol. For example, the group index may be mod(period index*m, number of groups). m may be 1 or greater.

[0083] As in the example of Figure 6, the UE may hop between groups of measurement targets for each symbol, in which case the measurement target group index may be a function of the symbol index.

[0084] <<Aspects 1-3>> The periodicity of the SSB / CSI-RS may be defined / configured using a first periodicity and a second periodicity.

[0085] As shown in the example of Fig. 7, only the first period may be specified / configured, and the second period may be the first period x the number of groups. The number of groups may be specified in the specifications, may be notified / broadcast by the MIB / SIB / PBCH, etc., may be blind detected by the UE, or may be configured by the RRC IE.

[0086] The first period may be the same as or different from the period (transmission period) of SSB / CSI-RS defined in existing standards.

[0087] The time from indication to application of the TCI condition may be determined based on the second period.

[0088] According to this embodiment, the UE can properly receive / measure / detect the SSB.

[0089] <Second embodiment> This embodiment relates to SSB / CSI-RS to be measured.

[0090] In Rel. 15, the UE measures all configured / specified SSBs and reports / uses the beam with the best measurement result. During random access channel (RACH) transmission, the UE transmits the physical random access channel (PRACH) in the PRACH occasion corresponding to the SSB with the highest received power. After RRC connection establishment, the UE reports to the base station one, two, or four SSB resource indicators (SSBRI) / CSI-RS resource indicators (CRI) with the highest L1-reference signal received power (RSRP) / L1-signal-to-interference and noise ratio (SINR) values ​​from the configured SSBs / CSI-RSs, along with the L1-RSRP / L1-SINR values, in layer 1 (L1) beam reporting.

[0091] When the number of beams increases, searching all beams takes time and becomes inefficient. Because it is expected that beam switching will occur, such as switching from a currently used beam to a nearby beam, the UE does not need to search all beams. For example, in the example of Figure 8, among SSBs #0 to #16 in the coverage area of ​​TRP (cell) #1, it is expected that the beam of SSB #9 in use will be switched to one of the nearby SSBs #4, #5, #6, #8, #10, #13, #14, or #15.

[0092] The UE may select a specific (measurement target) SSB / CSI-RS from all (configured / defined) SSB / CSI-RS and receive / measure / detect the specific SSB / CSI-RS.

[0093] The trigger for receiving / measuring / detecting SSB / CSI-RS may be at least one or all of the following: when measuring / reporting L1-RSRP / L1-SINR / L3-RSRP / L3-SINR, when determining a PRACH occasion for PRACH transmission, when determining a new beam RS in BFR, and when measuring for an event-based beam report. The UE may report the top X indexes of the measurement results from among the indexes of SSB / CSI-RS to be measured to the base station.

[0094] The index of the current (in use) SSB / CSI-RS may be the TCI state / spatial relationship set for the current PDCCH / PDSCH / PUCCH / PUSCH / SRS / CSI-RS, or the TCI state set for the PDCCH, or the DL TCI state or joint TCI state set for the unified TCI state (common TCI state), or the index of the SSB / CSI-RS (SSBRI / CRI) corresponding to the index of the best beam reported by the L1-RSRP / L1-SINR beam report.

[0095] The method for selecting a particular SSB / CSI-RS may follow at least one of the following selection methods 1 and 2.

[0096] <<Selection Method 1>> A correspondence relationship (association, state transition relationship from the current SSB / CSI-RS index to the SSB / CSI-RS index to be measured) between the current SSB / CSI-RS index and the SSB / CSI-RS index to be measured may be notified / configured. In the example of Fig. 9, the correspondence relationship may indicate association of each current SSB / CSI-RS index with one or more SSB / CSI-RS indexes to be measured.

[0097] When determining whether to perform beam switching, the UE may determine whether the measurement result of the SSB / CSI-RS to be measured is better or worse than the measurement result of the current SSB / CSI-RS. Even if the index of the SSB / CSI-RS to be measured is not explicitly notified, the index of the SSB / CSI-RS to be measured may include the index of the current SSB / CSI-RS. However, when determining a new beam RS in BFR, the index of the current SSB / CSI-RS may not be included in the index of the SSB / CSI-RS to be measured because it corresponds to a failed beam.

[0098] <<Selection Method 2>> The UE may determine the index of the SSB / CSI-RS to be measured (specific index of the multiple SSB / CSI-RSs) from the index of the current SSB / CSI-RS according to a rule, which may be at least one of the following rules 1 to 4:

[0099] [Rule 1] When groups are defined in the first embodiment, the index of the SSB / CSI-RS to be measured may be the index of all SSB / CSI-RSs in the group including the index of the current SSB / CSI-RS, or may be the index of SSB / CSI-RSs in the group excluding the index of the current SSB / CSI-RS. In the example of Figure 10A, the current SSB#1 is included in group#1. The UE may select SSB#0 to SSB#63 in group#1, the same as the current SSB, as the measurement target.

[0100] By limiting the number of SSBs to be measured to a specific number or less in one period / cycle, the UE can receive / measure / detect all SSBs to be measured in one period / cycle. The specific number may be the number of SSBs in one group.

[0101] The number of SSBs to be measured does not have to be limited to a specific number within one period / cycle. In this case, the UE may receive one SSB in the same symbol and receive / measure / detect all SSBs to be measured over multiple periods / cycles, or may use multiple panels to receive multiple SSBs in the same symbol and receive / measure / detect all SSBs to be measured within one period / cycle.

[0102] [Rule 2] The index of the SSB / CSI-RS to be measured may be a certain number of SSB / CSI-RS indices before or after the index of the current SSB / CSI-RS, or a certain number of SSB / CSI-RS indices within a range including the index of the current SSB / CSI-RS. For example, if the current SSB / CSI-RS index is m and the number of SSB / CSI-RS indices to be measured is N, the range of SSB / CSI-RS indices to be measured may be N SSB / CSI-RS indices from SSB / CSI-RS index m-floor(N / 2) to SSB / CSI-RS index m+ceil(N / 2)-1.

[0103] The formula for calculating the index of the SSB / CSI-RS to be measured is not limited to this formula. The index of the SSB / CSI-RS to be measured may be the N+1 SSB / CSI-RS indices from SSB / CSI-RS index m-floor(N / 2) to SSB / CSI-RS index m+ceil(N / 2) (centered around the current SSB / CSI-RS index m), or may be the N SSB / CSI-RS indices excluding the current SSB / CSI-RS index m from the N+1 SSB / CSI-RS indices from SSB / CSI-RS index m-floor(N / 2) to SSB / CSI-RS index m+ceil(N / 2) (centered around the current SSB / CSI-RS index m). Furthermore, floor / ceil / round may be used instead of floor / ceil. When the distance D from the index of the current SSB / CSI-RS is set, the SSB / CSI-RS index to be measured may be 2D+1 SSB / CSI-RS indices from SSB / CSI-RS index mD to SSB / CSI-RS index m+D (centered around the current SSB / CSI-RS index m), or may be 2D SSB / CSI-RS indices excluding the current SSB / CSI-RS index m among the 2D+1 SSB / CSI-RS indices from SSB / CSI-RS index mD to SSB / CSI-RS index m+D (centered around the current SSB / CSI-RS index m). The SSB / CSI-RS indices to be measured may be indices at a specific interval (e.g., 2) (centered around the current SSB / CSI-RS index m).

[0104] To prevent the SSB / CSI-RS index p obtained by the calculation formula from exceeding the number of SSB / CSI-RS indices Q or becoming negative, the index of the SSB / CSI-RS to be measured may be given by mod(p,Q).

[0105] SSB groups may not be used. In the example of Figure 10B, if SSBs #0 to #191 are being transmitted, the current SSB is SSB #65, and the number N of SSBs to be measured is 5, the SSBs to be measured may be SSBs #63 to #67.

[0106] The indices of the SSB / CSI-RS to be measured may be non-consecutive, for example, every other SSB / CSI-RS may be measured.

[0107] [Rule 3] The SSB / CSI-RS to be measured may be an SSB / CSI-RS that is adjacent on the time axis and adjacent to the current SSB / CSI-RS on the frequency axis (an SSB / CSI-RS that is adjacent / surrounding the current SSB / CSI-RS in the time-frequency plane). In the example of Figure 11A, groups #0 to #2 are transmitted, and each of groups #0 to #2 includes SSBs #0 to #63. The current SSB is SSB #1 of group #1, and the SSBs to be measured include SSBs #0 to #2 of group #0, SSBs #0 to #2 of group #1, and SSBs #0 to #2 of group #2.

[0108] In this case, the SSB to be measured may include multiple SSBs in the same symbol. In this case, the UE may receive one SSB in the same symbol and receive / measure / detect all of the SSBs to be measured over multiple periods / cycles, or may receive multiple SSBs in the same symbol using multiple panels and receive / measure / detect all of the SSBs to be measured in one period / cycle.

[0109] [Rule 4] The SSB / CSI-RS to be measured may be determined by adding n to the time index of the current SSB / CSI-RS and adding m to the frequency index of the current SSB / CSI-RS. In the example of Figure 11B, SSBs #0 to #191 are transmitted, where n = 1 and m = 1. The current SSB is SSB #0, and the next SSB to be measured is SSB #65, which is obtained by adding 1 to the time index and the frequency index. The next SSB to be measured is SSB #131, which is obtained by adding 1 to the time index and the frequency index.

[0110] According to this embodiment, the UE can appropriately determine the SSB / CSI-RS to be measured.

[0111] <Third embodiment> This embodiment relates to switching of measurement targets.

[0112] Operation A (FIG. 12B) of receiving / measuring / detecting all configured SSB / CSI-RS and operation B (FIG. 12A) of receiving / measuring / detecting a specific SSB / CSI-RS from the configured SSB / CSI-RS may be switched. The second embodiment may be applied to operation B.

[0113] Switching from operation A to operation B can avoid unnecessary SSB / CSI-RS reception / measurement / detection and reduce the time / delay required for SSB / CSI-RS reception / measurement / detection. By not receiving / measuring / detecting SSB / CSI-RS during certain periods, scheduling restrictions can be avoided and throughput can be increased.

[0114] In the examples of Figures 13A and 13B, groups #0 to #2 are transmitted. Groups #0 to #2 each include SSBs #0 to #63. Figure 13A shows an example of operation B. The UE selects group #1 from the configured groups #0 to #2 as the measurement target and performs reception / measurement / detection of only group #1. This allows the UE to complete reception / measurement / detection of all SSBs #0 to #63 to be measured in only one of periods #1 to #3, thereby reducing measurement delays. Figure 13B shows an example of operation A. The UE receives / measures / detects all SSBs in the configured groups #0 to #2, allowing the UE to complete reception / measurement / detection of all SSBs in periods #1 to #3.

[0115] The switching between operations A and B may follow at least one of the following switching methods 1 to 3.

[0116] <Switching Method 1> The switching may be performed by instruction from the base station (RRC IE / MAC CE / DCI).

[0117] An RRC IE / MAC CE that notifies the index of the SSB / CSI-RS to be measured may be defined in the specifications.

[0118] A specific field in the DCI having a field that triggers aperiodic CSI (A-CSI), such as DCI format 0_0 / 0_1 / 0_2 (e.g., a CSI request field), may be used to indicate switching. The specific field may conform to at least one of fields 1 and 2 below.

[0119] [Field 1] If configured by higher layer signaling, the DCI may include specific fields for switching.

[0120] [Field 2] The specific field may be a field that triggers A-CSI. The field that triggers A-CSI may indicate an indication index={0,1}, where 0 may indicate action A and 1 may indicate action B, or vice versa.

[0121] At least one of the association between the value (code point) of the A-CSI triggering field and the indication index, and the association between the A-CSI triggering state and the indication index may be defined in a specification or configured by higher layer signaling. In the example of Figure 14, the value of the A-CSI triggering field, the A-CSI triggering state, and the indication index are associated. The UE may determine at least one of the A-CSI triggering state and the indication index from the value of the A-CSI triggering field according to this association.

[0122] <Switching Method 2> The switching may be based on a condition. For example, if a condition is met, the UE may perform action B, and if the condition is not met, the UE may perform action A. The condition may include at least one of the following conditions 1 to 3 of action B:

[0123] [Operation B condition 1] The condition may be that the current SSB / CSI-RS reception / measurement / detection result / quality is good. The good result may be that the result is equal to or greater than a threshold. The result may be RSRP / SINR / RSRQ.

[0124] [Operation B condition 2] The condition may be that the top X results of reception / measurement / detection in operation B are good. A good result may be that the result is equal to or greater than a threshold. The result may be RSRP / SINR / RSRQ. The value of X may be set by higher layer signaling or may be defined in a specification. If the value of X is not set, the value of X may be a specific value. The specific value may be 1 or greater than 1.

[0125] [Operation B condition 3] The condition may be that a parameter related to the UE's moving speed is equal to or less than a threshold (or lower than a threshold). The parameter may be a Doppler shift, the number of handovers within a specific period, or the number of beams changed in an L1 / L3 beam report (a report of the top X beams) within a specific period (the number of beams in the report that are different from the beams in the immediately preceding report).

[0126] <<Switching Method 3>> The switching may be based on a condition. For example, if a condition is met, the UE may perform action A, and if the condition is not met, the UE may perform action B. The condition may include at least one of the following conditions 1 to 3 of action A:

[0127] [Operation A Condition 1] The condition may be that the result / quality of the current SSB / CSI-RS reception / measurement / detection is poor. The poor result may be that the result is below (or below) a threshold. The result may be RSRP / SINR / RSRQ.

[0128] [Operation A Condition 2] The condition may be that the top X results in operation B are bad. A bad result may be that the result is equal to or less than a threshold value (or lower). The result may be RSRP / SINR / RSRQ. The value of X may be set by higher layer signaling or may be defined in a specification. If the value of X is not set, the value of X may be a specific value. The specific value may be 1 or greater than 1.

[0129] [Operation A Condition 3] The condition may be that a parameter related to the UE's moving speed is equal to or greater than a threshold (or higher than a threshold). The parameter may be a Doppler shift, the number of handovers within a specific period, or the number of beams changed in an L1 / L3 beam report (a report of the top X beams) within a specific period (the number of beams in the report that are different from the beams in the immediately preceding report).

[0130] Although this embodiment describes switching between operations A and B, the switchable operations are not limited to these two operations. For example, the UE may receive / measure / detect a specific X number of configured SSB / CSI-RS, and the switching method in this embodiment may be applied to switching the value of X. For example, the switching method in this embodiment may be applied to switching between X=32 and X=64. For example, the switching method in this embodiment may be applied to switching between X=32, X=64, and X=192 (all SSB / CSI-RS, operation A). If the number of switchable operations is greater than two, the size (number of bits) of the indication index may be 2 or more bits.

[0131] According to this embodiment, the UE can appropriately switch the number of SSBs / CSI-RSs to be measured.

[0132] <Fourth embodiment> This embodiment relates to switching the type / group / width / number of beams.

[0133] The operation of receiving / measuring / detecting group A of SSB / CSI-RS covering an area (coverage area, service area, coverage) of a certain TRP / cell may be switched to the operation of receiving / measuring / detecting group B of SSB / CSI-RS covering that service area. The beam used for group B may be narrower (thinner) than the beam used for group A. The number of SSB / CSI-RS in group B may be greater than the number of SSB / CSI-RS in group A.

[0134] In the example of Figure 15A, SSB group A is transmitted. The beams used for the five SSBs in group A (SSB#0 to SSB#4) cover the coverage area of ​​TRP (cell) #1. In the example of Figure 15B, SSB group B is transmitted. The beams used for the 17 SSBs in group B (SSB#0 to SSB#16) cover the coverage area of ​​TRP (cell) #1.

[0135] In the example of FIG. 16A, group #0 corresponds to group A. The UE performs reception / measurement / detection for group #0 in each of periods #1 to #3. In the example of FIG. 16B, groups #1 and #2 correspond to group B. The UE performs reception / measurement / detection for group #1 in periods #1, #3, ..., and reception / measurement / detection for group #2 in periods #2, #4, ....

[0136] As with group A, the area of ​​one cell may be covered by multiple SSBs (beams used for them) in group #0. As with group B, the area of ​​one cell may be covered by multiple SSBs (beams used for them) in groups other than group #0 (groups #1 and #2).

[0137] The SSBs in Group A may be Rel. 15 SSBs.

[0138] The switching method / conditions of the third embodiment may be applied to switching between group A and group B. The switching may be performed by a base station instruction (RRC IE / MAC CE / DCI). The switching may be based on a condition. For example, if a condition is met, the UE may use group B, and if the condition is not met, the UE may use group A. For example, if a condition is met, the UE may use group A, and if the condition is not met, the UE may use group B.

[0139] The conditions for using Group B may include at least one of the following Group B conditions 1 to 2.

[0140] [Group B Condition 1] The condition may be that there is an instruction / configuration regarding group B from the base station. If there is no instruction / configuration regarding group B from the base station, the UE may receive / measure / detect only group A. If there is an instruction / configuration regarding group B from the base station, the UE may receive / measure / detect group B in addition to receiving / measure / detecting group A. In this case, quality can be improved compared to receiving / measure / detecting only group A. The UE may perform two-stage beam sweep. The first stage beam sweep may be receiving / measure / detecting group A. The second stage beam sweep may be receiving / measure / detecting group B.

[0141] [Group B Condition 2] The condition may be that the result / quality of reception / measurement / detection of SSB / CSI-RS in group A is not equal to or greater than the threshold. The result may be RSRP / SINR / RSRQ. If the result / quality of reception / measurement / detection of SSB / CSI-RS in group A is not equal to or greater than the threshold, the UE may perform reception / measurement / detection of group B.

[0142] For example, in beam reporting of L1-RSRP / L1-SINR, the UE may basically receive / measure / detect Group A and report SSBRI / CRI and L1-RSRP / L1-SINR of Group A. If conditions are met, the UE may receive / measure / detect Group B and report SSBRI / CRI and L1-RSRP / L1-SINR of Group B.

[0143] The trigger for receiving / measuring / detecting SSB / CSI-RS may be at least one or all of the following: when measuring L1-RSRP / L1-SINR / L3-RSRP / L3-SINR, when determining a PRACH occasion for PRACH transmission, when determining a new beam RS in BFR, and when measuring for an event-based beam report. The UE may report to the base station the top X indexes of the measurement results among the indexes of SSB / CSI-RS to be measured (at least one of groups A and B).

[0144] During the initial access procedure / random access procedure, the UE may receive / measure / detect SSBs in group A. During the initial access procedure / random access procedure, if the condition is met, the UE may use group B, and if the condition is not met, the UE may use group A.

[0145] The initial access procedure / random access procedure may follow at least one of PRACH1 to 3 below.

[0146] [PRACH1] The occasion / preamble of the PRACH corresponding to the SSB in group A may be different from the occasion / preamble of the PRACH corresponding to the SSB in group B. In this way, when receiving the PRACH, the base station can know whether the UE measured the SSB in group A or group B.

[0147] [PRACH2] The occasions / preambles of the PRACH corresponding to the SSBs in group A may be equal to the occasions / preambles of the PRACH corresponding to the SSBs in group B. This allows the number of required occasions / preambles of the PRACH to be approximately the same as the number of SSBs in group A, thereby improving resource utilization efficiency.

[0148] [PRACH3] The PRACH occasions corresponding to SSBs in group A may be the same as the PRACH occasions corresponding to SSBs in group B. The PRACH preambles corresponding to SSBs in group A may be different from the PRACH preambles corresponding to SSBs in group B. This allows the number of required PRACH occasions to be approximately the same as the number of SSBs in group A, thereby improving resource utilization efficiency. Furthermore, when receiving a PRACH, the base station can determine whether the UE has measured an SSB in group A or group B based on the preamble.

[0149] In this embodiment, switching between groups A and B has been described, but the groups to be switched are not limited to these two groups. The switching method in this embodiment may be applied to switching between group A and all groups including group A (groups A and B), or between group A and all groups including group A (groups A and B), or between group A and multiple groups including group A (e.g., groups #0 and #1, or groups #0 and #2), or between two or more groups (e.g., at least two of groups #0, #1, #2, groups #0 and #1, groups #0 and #2, groups #1 and #2, and groups #0, #1 and #2). Here, the quality of group A is not necessarily worse than the quality of group B. Although the index of group A (a group used for default reception / measurement / detection, a group with a small number of SSB / CSI-RS, and a group using a wide beam) is set to 0, it does not have to be 0.

[0150] According to this embodiment, the UE can appropriately switch the group / beam / number / area of ​​SSB / CSI-RS to be measured.

[0151] <Fifth embodiment> This embodiment relates to a method for signaling / setting / indicating / reporting an index of an SSB / CSI-RS.

[0152] When the base station configures / notifies the UE of SSB indices (for QCL source RS, PL-RS, PRACH triggered by PDCCH order, etc.), when reporting SSBRI / CRI in the L1 beam report in the UCI, etc., if the number of SSB / CSI-RS is more than 64, the indexes cannot be notified by the existing 6 bits. This is particularly problematic when the MAC CE / DCI notifies the SSB index and when the UCI notifies the index (SSBRI / CRI).

[0153] The method of reporting the SSB / CSI-RS index may follow at least one of the following reporting methods 1 to 3.

[0154] 《Notification method 1》 The number of bits (field size) for signaling / indicating / configuring / reporting the SSB / CSI-RS index may be larger than the number of bits for signaling / indicating / configuring / reporting the existing SSB / CSI-RS index. In the MAC CE / DCI / UCI / RRC IE, the size of the field for signaling the SSB / CSI-RS index may be larger than 6 bits. When reception / measurement / detection of more than 64 SSBs is configured, the size of the field for signaling the SSB / CSI-RS index may be larger than 6 bits. In the MAC CE / DCI / UCI / RRC IE, the size of the field for signaling the SSB / CSI-RS index may be variable according to the number of configured SSBs / CSI-RSs (or may depend on the number of configured SSBs / CSI-RSs).

[0155] 《Notification method 2》 The most significant X bits (or least significant X bits) of the SSB / CSI-RS index may indicate a group index. For example, the most significant X bits (or least significant X bits) of the SSB / CSI-RS index may indicate a group index, and the remaining Y bits may indicate the index of the SSB / CSI-RS within that group. At least one of X and Y may be configured by higher layer signaling or may be defined in a specification. The UE may determine X based on the configured number of groups. The UE may determine Y based on the number of SSB / CSI-RS within the configured group.

[0156] The most significant bit (MSB) or least significant bit (LSB) of the SSBRI / CRI field indicates whether the index indicated by that field is for SSB or CSI-RS, and the remaining bits may indicate at least one of a group index and an SSB / CSI-RS index.

[0157] 《Notification method 3》 The number of bits (field size) for signaling / indicating / configuring / reporting the SSB / CSI-RS index may be the same as the existing number of bits for signaling / indicating / configuring / reporting the SSB / CSI-RS index. The group index may be implicitly specified (the UE may determine the group index based on the signaled information). If the maximum number of SSBs is 64, the number of bits for signaling / indicating / configuring / reporting the SSB / CSI-RS index may be 6 bits. The number of bits for signaling / indicating / configuring / reporting the SSB / CSI-RS index is not limited to this number.

[0158] [Notification method 3-1] The number of bits (field size) for signaling / indicating / configuring / reporting the SSB / CSI-RS index may be the same as the number of bits for signaling / indicating / configuring / reporting the existing SSB / CSI-RS index. The UE may determine the group index using the SSB / CSI-RS index signaled by the MAC CE / DCI. The UE may also implicitly signal the group index using the SSB / CSI-RS index reported by the MAC CE / UCI.

[0159] [Notification method 3-2] It is considered that the group index is changed less frequently than the SSB / CSI-RS index. The group index and the SSB / CSI-RS index may be signaled / reported by separate MAC CE / DCI / UCI. The group index may be signaled / reported at long intervals (low frequency), and the SSB / CSI-RS index may be signaled / reported at short intervals (high frequency).

[0160] The group in this embodiment may be the group in the first embodiment, or may be the SSB / CSI-RS to be measured in the second embodiment.

[0161] According to this embodiment, the group / index of the SSB / CSI-RS can be signaled / reported / indicated / configured appropriately.

[0162] <Other embodiments> 《UE capability information / upper layer parameters》 Higher layer parameters (RRC IEs) / UE capabilities corresponding to the functions (features) in each of the above embodiments may be defined. The higher layer parameters may indicate whether the functions are enabled. The UE capabilities may indicate whether the UE supports the functions.

[0163] A UE for which higher layer parameters corresponding to the function are configured may perform the function. It may also be specified that "a UE for which higher layer parameters corresponding to the function are not configured shall not perform the function (for example, in accordance with Rel. 15 / 16)."

[0164] A UE that reports / transmits a UE capability indicating that it supports the function may perform the function. It may also be specified that "a UE that does not report a UE capability indicating that it supports the function shall not perform the function (e.g., in accordance with Rel. 15 / 16)."

[0165] If the UE reports / transmits a UE capability indicating that it supports the function and the corresponding upper layer parameter is configured, the UE may perform the function. It may also be specified that "if the UE does not report / transmit a UE capability indicating that it supports the function or if the corresponding upper layer parameter is not configured, the UE shall not perform the function (e.g., in accordance with Rel. 15 / 16)."

[0166] Which embodiment / option / choice / function of the above multiple embodiments is used may be configured by higher layer parameters, may be reported by the UE as a UE capability, may be specified in a specification, or may be determined by the reported UE capability and the configuration of higher layer parameters.

[0167] The UE capabilities may indicate whether the UE supports at least one of the following functions: Reception / measurement / detection of SSB / CSI-RS groups. The UE capabilities may indicate the maximum number of groups supported. If the UE does not report this number, the maximum number of groups supported for that UE may be 1. Receiving / measuring / detecting different SSB / CSI-RS (with different indices) in the same symbol.

[0168] The above UE capabilities / upper layer parameters allow the UE to achieve the above functions while maintaining compatibility with existing specifications.

[0169] (wireless communication system) The configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above embodiments of the present disclosure or a combination thereof.

[0170] 17 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 may be a system that realizes communication using Long Term Evolution (LTE) or 5th generation mobile communication system New Radio (5G NR) specified by the Third Generation Partnership Project (3GPP).

[0171] The wireless communication system 1 may also support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC may include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

[0172] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (MN), and the NR base station (gNB) is the secondary node (SN). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0173] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity in which both the MN and the SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0174] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with a relatively wide coverage, and base stations 12 (12a-12c) that are located within the macrocell C1 and form small cells C2 that are smaller than the macrocell C1. A user terminal 20 may be located within at least one of the cells. The locations and numbers of the cells and user terminals 20 are not limited to the embodiment shown in the figure. Hereinafter, when there is no need to distinguish between the base stations 11 and 12, they will be collectively referred to as base station 10.

[0175] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CC) and dual connectivity (DC).

[0176] Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band above 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may be a frequency band higher than FR2.

[0177] Furthermore, the user terminal 20 may perform communication using at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD) in each CC.

[0178] The multiple base stations 10 may be connected by wire (for example, optical fiber conforming to the Common Public Radio Interface (CPRI), an X2 interface, or the like) or wirelessly (for example, NR communication). For example, when NR communication is used as a backhaul between the base stations 11 and 12, the base station 11 corresponding to the upper station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0179] The base station 10 may be connected to the core network 30 directly or via another base station 10. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), and the like.

[0180] The user terminal 20 may be a terminal compatible with at least one of communication methods such as LTE, LTE-A, and 5G.

[0181] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the radio communication system 1. For example, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), or the like may be used in at least one of the downlink (DL) and uplink (UL).

[0182] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (for example, other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0183] In the wireless communication system 1, a downlink shared channel (Physical Downlink Shared Channel (PDSCH)) shared by each user terminal 20, a broadcast channel (Physical Broadcast Channel (PBCH)), a downlink control channel (Physical Downlink Control Channel (PDCCH)), etc. may be used as the downlink channel.

[0184] Furthermore, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), etc. may be used as an uplink channel.

[0185] The PDSCH transmits user data, higher layer control information, System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit Master Information Block (MIB).

[0186] Lower layer control information may be transmitted by the PDCCH. The lower layer control information may include, for example, Downlink Control Information (DCI) including scheduling information for at least one of the PDSCH and the PUSCH.

[0187] Note that the DCI for scheduling the PDSCH may be referred to as a DL assignment, a DL DCI, etc., and the DCI for scheduling the PUSCH may be referred to as an UL grant, a UL DCI, etc. Note that the PDSCH may be interpreted as DL data, and the PUSCH may be interpreted as UL data.

[0188] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources to search for DCI. The search space corresponds to a search region and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor a CORESET associated with a certain search space based on the search space configuration.

[0189] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be called a search space set. Note that the terms "search space," "search space set," "search space setting," "search space set setting," "CORESET," "CORESET setting," etc. in the present disclosure may be read interchangeably.

[0190] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), acknowledgement information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0191] In the present disclosure, downlink, uplink, etc. may be expressed without adding "link." Also, various channels may be expressed without adding "Physical" to the beginning.

[0192] In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted as DL-RS.

[0193] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including the SS (PSS, SSS) and the PBCH (and DMRS for the PBCH) may be referred to as an SS / PBCH block, an SS Block (SSB), or the like. Note that the SS, SSB, and the like may also be referred to as reference signals.

[0194] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), etc. may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may also be called a user equipment-specific reference signal (UE-specific reference signal).

[0195] (base station) 18 is a diagram showing an example of the configuration of a base station according to an embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that the base station may include one or more of each of the control unit 110, the transceiver unit 120, the transceiver antenna 130, and the transmission line interface 140.

[0196] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the base station 10 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0197] The control unit 110 performs overall control of the base station 10. The control unit 110 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0198] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurement, etc. The control unit 110 may generate data to be transmitted as signals, control information, sequences, etc., and transfer them to the transceiver unit 120. The control unit 110 may perform call processing (setting up, releasing, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0199] The transceiver unit 120 may include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may include a transmission processing unit 1211 and a reception processing unit 1212. The transceiver unit 120 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0200] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 1211 and an RF unit 122. The receiving unit may be composed of a reception processing unit 1212, an RF unit 122, and a measurement unit 123.

[0201] The transmitting and receiving antenna 130 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0202] The transceiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 120 may receive the above-mentioned uplink channel, uplink reference signal, etc.

[0203] The transceiver 120 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0204] The transceiver 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0205] The transceiver 120 (transmission processor 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0206] The transmitting / receiving unit 120 (RF unit 122) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna .

[0207] On the other hand, the transmitting / receiving unit 120 (RF unit 122) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna .

[0208] The transceiver 120 (reception processing unit 1212) may apply reception processing such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, thereby acquiring user data, etc.

[0209] The transceiver 120 (measurement unit 123) may perform measurements on the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurements, Channel State Information (CSI) measurements, etc. based on the received signal. The measurement unit 123 may measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 110.

[0210] The transmission path interface 140 may transmit and receive signals (backhaul signaling) between devices included in the core network 30, other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0211] The transmitting section and receiving section of the base station 10 in the present disclosure may be configured by at least one of the transmitting / receiving section 120, the transmitting / receiving antenna 130, and the transmission path interface 140.

[0212] The transceiver 120 may transmit multiple reference signals, each using a different resource. The controller 110 may control association of one of the multiple reference signals with two or more of the multiple reference signals. The number of the multiple reference signals may be greater than 64.

[0213] The control unit 110 may determine one operation from a plurality of operations including a first operation in which the user terminal 20 receives a plurality of first reference signals among a plurality of reference signals, and a second operation in which the user terminal 20 receives a plurality of second reference signals among the plurality of reference signals. The transceiver unit 120 may transmit information indicating the one operation. The number of the plurality of second reference signals may be smaller than the number of the plurality of first reference signals.

[0214] The control unit 110 may determine one operation from a plurality of operations including a first operation in which the user terminal 20 receives a plurality of first reference signals in a cell and a second operation in which the user terminal 20 receives a plurality of second reference signals in the cell. The transceiver unit 120 may transmit information indicating the one operation. The number of the plurality of second reference signals may be greater than the number of the plurality of first reference signals.

[0215] (user terminal) 19 is a diagram showing an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transceiver unit 220, and a transceiver antenna 230. Note that the user terminal 20 may include one or more of each of the control unit 210, the transceiver unit 220, and the transceiver antenna 230.

[0216] Note that this example mainly shows functional blocks of the characteristic parts of the present embodiment, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0217] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured from a controller, a control circuit, and the like that are explained based on common understanding in the technical field to which the present disclosure relates.

[0218] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may also control transmission and reception, measurement, etc. using the transceiver unit 220 and the transceiver antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 220.

[0219] The transceiver unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may be configured from a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0220] The transmitting / receiving unit 220 may be configured as an integrated transmitting / receiving unit, or may be composed of a transmitting unit and a receiving unit. The transmitting unit may be composed of a transmission processing unit 2211 and an RF unit 222. The receiving unit may be composed of a reception processing unit 2212, an RF unit 222, and a measurement unit 223.

[0221] The transmitting / receiving antenna 230 can be configured as an antenna described based on common understanding in the technical field to which the present disclosure pertains, such as an array antenna.

[0222] The transceiver 220 may receive the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transceiver 220 may transmit the above-mentioned uplink channel, uplink reference signal, etc.

[0223] The transceiver 220 may form at least one of a transmission beam and a reception beam using digital beamforming (for example, precoding), analog beamforming (for example, phase rotation), or the like.

[0224] The transceiver 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

[0225] The transceiver 220 (transmission processor 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0226] Whether or not to apply DFT processing may be based on the setting of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the transmission processing to transmit the channel using a DFT-s-OFDM waveform, and when transform precoding is not enabled, the transceiver unit 220 may not perform DFT processing as the transmission processing.

[0227] The transmitting / receiving unit 220 (RF unit 222) may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal, and transmit the radio frequency band signal via the transmitting / receiving antenna 230.

[0228] On the other hand, the transmitting / receiving unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transmitting / receiving antenna 230.

[0229] The transceiver 220 (reception processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal to acquire user data, etc.

[0230] The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurement, CSI measurement, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

[0231] The transmitting section and receiving section of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving section 220 and the transmitting / receiving antenna 230.

[0232] The transceiver 220 may receive one reference signal from among a plurality of reference signals (e.g., SSB / CSI-RS) that are transmitted (e.g., TDM / FDM / CDM / SDM) using different resources (e.g., time resources / frequency resources / code resources / space resources). The controller 210 may control reception of two or more reference signals (e.g., an SSB / CSI-RS to be measured, a specific SSB / CSI-RS) from among the plurality of reference signals based on the reception result of the one reference signal. The number of the plurality of reference signals may be greater than 64.

[0233] The plurality of reference signals may be divided into a plurality of groups, and all of the reference signals in the plurality of groups may be time division multiplexed.

[0234] The plurality of groups may correspond to a plurality of time periods, and the transmitting / receiving unit 220 may receive the plurality of groups during the plurality of time periods, respectively.

[0235] The transceiver 220 may receive the multiple groups in the same symbol.

[0236] The control unit 210 may determine one operation from a plurality of operations including a first operation (e.g., operation A) of receiving a plurality of first reference signals among a plurality of reference signals (e.g., SSB / CSI-RS in a cell) and a second operation (e.g., operation B) of receiving a plurality of second reference signals among the plurality of reference signals. The transceiver unit 220 may receive at least one of the plurality of first reference signals and the plurality of second reference signals according to the one operation. The number of the plurality of second reference signals may be less than the number of the plurality of first reference signals.

[0237] The plurality of reference signals may be divided into a plurality of groups, and the plurality of second reference signals may be one of the plurality of groups.

[0238] The control unit 210 may determine the action based on the received information.

[0239] The control unit 210 may determine the one action according to whether a condition is met.

[0240] The control unit 210 may determine one operation from a plurality of operations including a first operation of receiving a plurality of first reference signals (e.g., group A, SSB / CSI-RS using a wide beam) in a cell and a second operation of receiving a plurality of second reference signals (e.g., group B, SSB / CSI-RS using a narrow beam) in the cell. The transceiver unit 220 may receive at least one of the plurality of first reference signals and the plurality of second reference signals according to the one operation. The number of the plurality of second reference signals may be greater than the number of the plurality of first reference signals.

[0241] The plurality of first reference signals may be a plurality of synchronization signal blocks within the cell.

[0242] The control unit 210 may determine the action based on the received information.

[0243] The control unit 210 may determine the one action according to whether a condition is met.

[0244] (Hardware configuration) The block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may also be realized by combining the single device or multiple devices with software.

[0245] Here, the functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission may be called a transmitting unit, transmitter, etc. As mentioned above, the implementation method of each is not particularly limited.

[0246] For example, a base station, a user terminal, or the like according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 20 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. The above-described base station 10 and user terminal 20 may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0247] In this disclosure, terms such as apparatus, circuit, device, section, unit, etc. may be read interchangeably. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0248] For example, although only one processor 1001 is shown, there may be multiple processors. Furthermore, processing may be performed by one processor, or processing may be performed by two or more processors simultaneously, serially, or in other ways. Furthermore, processor 1001 may be implemented by one or more chips.

[0249] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading predetermined software (programs) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, control communication via the communication device 1004, and control at least one of reading and writing data in the memory 1002 and the storage 1003.

[0250] The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transmission / reception unit 120 (220), etc. may be realized by the processor 1001.

[0251] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 110 (210) may be realized by a control program stored in the memory 1002 and running on the processor 1001, and the other functional blocks may be realized in a similar manner.

[0252] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, a cache, a main memory, or the like. The memory 1002 may store executable programs (program codes), software modules, and the like for implementing a wireless communication method according to an embodiment of the present disclosure.

[0253] Storage 1003 is a computer-readable recording medium and may be constituted by at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, stick, key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as a secondary storage device.

[0254] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmission / reception unit 120 (220), transmission / reception antenna 130 (230), etc. may be realized by the communication device 1004. The transmission / reception unit 120 (220) may be implemented as a transmission unit 120a (220a) and a reception unit 120b (220b) that are physically or logically separated.

[0255] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0256] Furthermore, each device, such as the processor 1001 and the memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

[0257] Furthermore, the base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized using such hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0258] (Variation) Note that terms explained in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0259] A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0260] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and may indicate at least one of, for example, a subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic prefix length, a transmission time interval (TTI), the number of symbols per TTI, a radio frame structure, a specific filtering process performed by a transceiver in the frequency domain, and a specific windowing process performed by a transceiver in the time domain.

[0261] A slot may be composed of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol), and may be a time unit based on numerology.

[0262] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (PUSCH) mapping type B.

[0263] A radio frame, a subframe, a slot, a minislot, and a symbol all represent time units for transmitting signals. The radio frame, the subframe, the slot, the minislot, and the symbol may be referred to by other names corresponding to the radio frame, the subframe, the slot, the minislot, and the symbol. Note that the time units such as a frame, a subframe, a slot, a minislot, and a symbol in the present disclosure may be interchangeable.

[0264] For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0265] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. However, the definition of TTI is not limited to this.

[0266] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0267] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0268] A TTI having a time length of 1 ms may be called a regular TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0269] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0270] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0271] In addition, an RB may include one or more symbols in the time domain and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0272] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0273] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0274] A Bandwidth Part (BWP), which may also be referred to as a fractional bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within that BWP.

[0275] The BWP may include an UL BWP (a BWP for UL) and a DL BWP (a BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0276] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0277] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0278] Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values ​​from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by a predetermined index.

[0279] The names used for parameters and the like in this disclosure are not intended to be limiting in any way. Furthermore, the mathematical expressions and the like using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0280] The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0281] Furthermore, information, signals, etc. may be output from a higher layer to a lower layer and / or from a lower layer to a higher layer. Information, signals, etc. may be input / output via multiple network nodes.

[0282] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0283] Notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, notification of information in the present disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI) and Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB) and System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0284] Note that the physical layer signaling may be called Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. Furthermore, the RRC signaling may be called an RRC message, such as an RRC connection setup message or an RRC connection reconfiguration message. Furthermore, the MAC signaling may be notified using, for example, a MAC Control Element (CE).

[0285] Furthermore, notification of specified information (e.g., notification that "it is X") is not limited to explicit notification, but may be made implicitly (e.g., by not notifying the specified information or by notifying other information).

[0286] The determination may be made by a value represented by one bit (0 or 1), by a Boolean value represented by true or false, or by a comparison of numerical values ​​(e.g., comparison with a predetermined value).

[0287] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0288] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), then these wired and / or wireless technologies are included within the definition of transmission media.

[0289] As used in this disclosure, the terms "system" and "network" may be used interchangeably. A "network" may refer to devices included in the network (e.g., base stations).

[0290] In the present disclosure, terms such as "precoding," "precoder," "weight (precoding weight)," "Quasi-Co-Location (QCL)," "Transmission Configuration Indication state (TCI state)," "spatial relation," "spatial domain filter," "transmit power," "phase rotation," "antenna port," "antenna port group," "layer," "number of layers," "rank," "resource," "resource set," "resource group," "beam," "beam width," "beam angle," "antenna," "antenna element," "panel," etc. may be used interchangeably.

[0291] In this disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNB (eNodeB)," "gNB (gNodeB)," "access point," "transmission point (TP)," "reception point (RP)," "transmission / reception point (TRP)," "panel," "cell," "sector," "cell group," "carrier," "component carrier," etc. may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0292] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The term "cell" or "sector" refers to a part or the entire coverage area of ​​a base station and / or base station subsystem that provides communication service within this coverage.

[0293] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0294] A mobile station may also be referred to as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

[0295] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, etc. Note that at least one of the base station and the mobile station may be a device mounted on a moving object, the moving object itself, etc.

[0296] The mobile body is a movable object that can move at any speed and naturally includes cases where the mobile body is stationary. Examples of the mobile body include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcars, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and objects mounted thereon. The mobile body may also be a mobile body that moves autonomously based on an operation command.

[0297] The mobile object may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). Note that at least one of the base station and the mobile station may also include devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0298] 21 is a diagram showing an example of a vehicle according to an embodiment. A vehicle 40 includes a drive unit 41, a steering unit 42, an accelerator pedal 43, a brake pedal 44, a shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, an electronic control unit 49, various sensors (including a current sensor 50, an RPM sensor 51, an air pressure sensor 52, a vehicle speed sensor 53, an acceleration sensor 54, an accelerator pedal sensor 55, a brake pedal sensor 56, a shift lever sensor 57, and an object detection sensor 58), an information service unit 59, and a communication module 60.

[0299] The drive unit 41 is configured with at least one of an engine, a motor, and a hybrid of an engine and a motor, for example. The steering unit 42 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by the user.

[0300] The electronic control unit 49 is composed of a microprocessor 61, memory (ROM, RAM) 62, and a communication port (e.g., an input / output (IO) port) 63. Signals are input to the electronic control unit 49 from various sensors 50-58 provided in the vehicle. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

[0301] The signals from the various sensors 50-58 include a current signal from a current sensor 50 that senses the current of the motor, a rotation speed signal of the front wheels 46 / rear wheels 47 obtained by a rotation speed sensor 51, an air pressure signal of the front wheels 46 / rear wheels 47 obtained by an air pressure sensor 52, a vehicle speed signal obtained by a vehicle speed sensor 53, an acceleration signal obtained by an acceleration sensor 54, a depression amount signal of the accelerator pedal 43 obtained by an accelerator pedal sensor 55, a depression amount signal of the brake pedal 44 obtained by a brake pedal sensor 56, an operation signal of the shift lever 45 obtained by a shift lever sensor 57, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 58.

[0302] The information service unit 59 is composed of various devices, such as a car navigation system, an audio system, speakers, a display, a television, and a radio, for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 59 uses information acquired from external devices via the communication module 60 or the like to provide various information / services (for example, multimedia information / multimedia services) to the occupants of the vehicle 40.

[0303] The information service unit 59 may include input devices (e.g., keyboards, mice, microphones, switches, buttons, sensors, touch panels, etc.) that accept input from the outside, and may also include output devices (e.g., displays, speakers, LED lamps, touch panels, etc.) that output to the outside.

[0304] The driving assistance system unit 64 is configured with various devices that provide functions for preventing accidents and reducing the driver's driving burden, such as millimeter-wave radar, Light Detection and Ranging (LiDAR), cameras, positioning locators (e.g., Global Navigation Satellite System (GNSS)), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyro systems (e.g., Inertial Measurement Units (IMUs), Inertial Navigation Systems (INSs)), Artificial Intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driving assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driving assistance functions or autonomous driving functions.

[0305] The communication module 60 can communicate with the microprocessor 61 and components of the vehicle 40 via the communication port 63. For example, the communication module 60 transmits and receives data (information) via the communication port 63 to and from the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and the various sensors 50-58, which are provided in the vehicle 40.

[0306] The communication module 60 is a communication device that can be controlled by the microprocessor 61 of the electronic control unit 49 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 60 may be located either inside or outside the electronic control unit 49. The external device may be, for example, the above-mentioned base station 10 or user terminal 20. Furthermore, the communication module 60 may be, for example, at least one of the above-mentioned base station 10 and user terminal 20 (or may function as at least one of the base station 10 and user terminal 20).

[0307] The communication module 60 may transmit at least one of signals from the above-mentioned various sensors 50-58 input to the electronic control unit 49, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 59 to an external device via wireless communication. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 60 may include information based on the above-mentioned input.

[0308] The communication module 60 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from external devices and displays it on an information service unit 59 provided in the vehicle. The information service unit 59 may also be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH received by the communication module 60 (or data / information decoded from the PDSCH)).

[0309] Furthermore, the communication module 60 stores various information received from external devices in a memory 62 that can be used by the microprocessor 61. Based on the information stored in the memory 62, the microprocessor 61 may control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, various sensors 50-58, and the like provided in the vehicle 40.

[0310] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, terms such as uplink channel and downlink channel may be read as sidelink channel.

[0311] Similarly, the user terminal in the present disclosure may be read as a base station, in which case the base station 10 may be configured to have the functions of the user terminal 20 described above.

[0312] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME) and a Serving-Gateway (S-GW)), or a combination thereof.

[0313] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the specific order presented.

[0314] Each aspect / embodiment described in the present disclosure may be a technology other than Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (x is, for example, an integer or decimal number)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE The present invention may be applied to systems that use 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other appropriate wireless communication methods, or to next-generation systems that are expanded, modified, created, or defined based on these. It may also be applied to a combination of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0315] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0316] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0317] The term "determining," as used in this disclosure, may encompass a wide variety of actions. For example, "determining" may be considered to be judging, calculating, computing, processing, deriving, investigating, looking up, search, inquiry (e.g., looking up in a table, database, or another data structure), ascertaining, etc.

[0318] Additionally, "determining" may be considered to be "determining" receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), etc.

[0319] Also, "decision" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. In other words, "decision" may be considered to be "deciding" on some action.

[0320] Furthermore, "judgment (decision)" may be read as "assuming," "expecting," "considering," or the like.

[0321] The "maximum transmit power" in this disclosure may mean the maximum value of transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

[0322] As used in this disclosure, the terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access."

[0323] In this disclosure, when two elements are connected, they may be considered to be "connected" or "coupled" to one another using one or more wires, cables, printed electrical connections, etc., as well as using electromagnetic energy having wavelengths in the radio frequency range, microwave range, light (both visible and invisible) range, etc., as some non-limiting and non-exhaustive examples.

[0324] In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "coupled" may also be interpreted in the same way as "different."

[0325] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0326] In this disclosure, where articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0327] Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the invention as defined by the description of the claims. Therefore, the description of the present disclosure is intended to be illustrative and explanatory and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. a receiving unit that receives a plurality of first reference signals among a plurality of reference signals when performing an event-based beam report; a control unit that determines one operation from a plurality of operations including a first operation of receiving the plurality of first reference signals and a second operation of receiving a plurality of second reference signals from the plurality of reference signals based on a radio resource control information element transmitted from a base station; the receiving unit receives at least one of the plurality of first reference signals and the plurality of second reference signals in accordance with the one operation; the plurality of first reference signals include the plurality of second reference signals; A terminal, wherein the number of the plurality of second reference signals is smaller than the number of the plurality of first reference signals.

2. receiving a plurality of first reference signals among a plurality of reference signals when performing event-based beam reporting; determining one operation from a plurality of operations including a first operation of receiving the plurality of first reference signals and a second operation of receiving a plurality of second reference signals from the plurality of reference signals based on a radio resource control information element transmitted from a base station; receiving at least one of the first and second reference signals according to the one operation; the plurality of first reference signals include the plurality of second reference signals; A wireless communication method for a terminal, wherein the number of the plurality of second reference signals is smaller than the number of the plurality of first reference signals.

3. a transmitting unit that transmits a plurality of first reference signals among a plurality of reference signals when a terminal performs an event-based beam report; a control unit that instructs one operation from a plurality of operations including a first operation in which the terminal receives the plurality of first reference signals and a second operation in which the terminal receives a plurality of second reference signals among the plurality of reference signals, using a radio resource control information element to be transmitted to the terminal; the transmitter transmits at least one of the plurality of first reference signals and the plurality of second reference signals received according to the one operation; the plurality of first reference signals include the plurality of second reference signals; A base station, wherein the number of the plurality of second reference signals is less than the number of the plurality of first reference signals.

4. A system having a terminal and a base station, The terminal a receiving unit that receives a plurality of first reference signals among a plurality of reference signals when performing an event-based beam report; a control unit that determines one operation from a plurality of operations including a first operation of receiving the plurality of first reference signals and a second operation of receiving a plurality of second reference signals from the plurality of reference signals based on a radio resource control information element transmitted from the base station; the receiving unit receives at least one of the plurality of first reference signals and the plurality of second reference signals in accordance with the one operation; The base station a transmitter configured to transmit at least one of the plurality of first reference signals and the plurality of second reference signals received in accordance with the one operation; the plurality of first reference signals include the plurality of second reference signals; A system, wherein the number of the plurality of second reference signals is less than the number of the plurality of first reference signals.

Images