Terminal, wireless communication method and system

Abstract

A terminal according to one embodiment of the present disclosure includes: a reception unit that receives information pertaining to a timing advance group corresponding to a plurality of transmission / reception points of a specific cell; and a control unit that, if the plurality of transmission / reception points belong to the same timing advance group, controls the timing advance of each of the plurality transmission / reception points, on the basis of a timing advance command corresponding to only one transmission / reception point or a timing advance command corresponding to a plurality of transmission points.

Description

Terminal, wireless communication method and base station

[0001] The present disclosure relates to a terminal, a wireless communication method, and a base station in a next-generation mobile communication system.

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

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

[0004] 3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010

[0005] In future wireless communication systems (e.g., wireless communication systems after Rel. 16 / 5G), it is expected that communications will be controlled using multiple transmission / reception points (e.g., Multi-TRP (MTRP)) in a serving cell, or communications will be controlled based on inter-cell mobility including non-serving cells.

[0006] However, when UL transmission is performed to multiple transmission / reception points, how to control the UL transmission (for example, timing advance control) becomes an issue. If the UL transmission to each transmission / reception point is not appropriately controlled, the quality of communication using multiple transmission / reception points may deteriorate.

[0007] The present disclosure has been made in consideration of such points, and one of its objectives is to provide a terminal, a wireless communication method, and a base station that are capable of communicating appropriately even when communicating using multiple transmission points.

[0008] A terminal according to one aspect of the present disclosure includes a receiving unit that receives information regarding timing advance groups corresponding to multiple transmission and reception points of a specific cell, and a control unit that, when the multiple transmission and reception points belong to the same timing advance group, controls the timing advance of each of the multiple transmission and reception points based on a timing advance command corresponding to only one transmission and reception point or a timing advance command corresponding to multiple transmission points.

[0009] According to one aspect of the present disclosure, communication can be performed appropriately even when communication is performed using multiple transmission points.

[0010] 1A to 1D are diagrams illustrating an example of multi-TRP. FIGS. 2A and 2B are diagrams illustrating an example of inter-cell mobility. FIG. 3 is a diagram illustrating an example of a timing advance group (TAG) to which cells included in a cell group belong. FIG. 4 is a diagram illustrating an example of a MAC CE for a timing advance command. FIG. 5 is a diagram illustrating an example of a case where multiple TRPs corresponding to a serving cell belong to different TAGs. FIG. 6 is a diagram illustrating an example of TAG configuration according to the first embodiment. FIGS. 7A and 7B are diagrams illustrating another example of TAG configuration according to the first embodiment. FIG. 8 is a diagram illustrating an example of operation after expiration of a time alignment timer according to the first embodiment. FIG. 9 is a diagram illustrating another example of operation after expiration of a time alignment timer according to the first embodiment. FIGS. 10A and 10B are diagrams illustrating an example of operation after expiration of a time alignment timer according to the second embodiment. FIG. 11 is a diagram illustrating an example of TAG configuration according to a third embodiment. FIG. 12 is a diagram illustrating an example of TAG configuration according to a fourth embodiment. FIG. 13 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. Fig. 14 is a diagram illustrating an example of the configuration of a base station according to an embodiment. Fig. 15 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. Fig. 16 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. Fig. 17 is a diagram illustrating an example of a vehicle according to an embodiment.

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

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

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

[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 identified based on a spatial QCL. The QCL (or at least one element of the QCL) in the present disclosure may be replaced with sQCL (spatial QCL).

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

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

[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 channel of interest (in other words, the Reference Signal (RS) for that channel) and another signal (e.g., another RS). The TCI state may be set (indicated) by higher layer signaling, physical layer signaling, or a combination thereof.

[0020] 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, etc., or a combination thereof.

[0021] The MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. The broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0022] The physical layer signaling may be, for example, Downlink Control Information (DCI).

[0023] The channel / signal to which the TCI state is applied may be called a target channel / reference signal (target channel / RS), or simply a target, and the other signal may be called a reference reference signal (reference RS), a source RS, or simply a reference.

[0024] The channel for which the TCI state or spatial relationship is set (specified) may be, for example, at least one of a physical downlink shared channel (PDSCH), a physical downlink control channel (PDCCH), a physical uplink shared channel (PUSCH), and a physical uplink control channel (PUCCH).

[0025] Furthermore, the RS that has a QCL relationship with the channel may be at least one of, for example, a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), a tracking CSI-RS (also called a tracking reference signal (TRS)), a QCL detection reference signal (also called a QRS), a demodulation reference signal (DMRS), etc.

[0026] An SSB is a signal block including at least one of a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). An SSB may also be referred to as an SS / PBCH block.

[0027] An RS of QCL type X in a TCI state may refer to an RS that has a QCL type X relationship with a certain channel / signal (DMRS), and this RS may be called a QCL source of QCL type X in the TCI state.

[0028] (Multi-TRP) In NR, one or more transmission / reception points (Transmission / Reception Points (TRP)) (multi-TRP) are considered to perform DL transmission to a UE using one or more panels (multi-panels). Also, it is considered that a UE performs UL transmission to one or more TRPs.

[0029] Note that multiple TRPs may correspond to the same cell identifier (ID), or different cell IDs, which may be physical cell IDs (e.g., PCIs) or virtual cell IDs.

[0030] 1A-1D illustrate an example of a multi-TRP scenario, assuming, but not limited to, that each TRP is capable of transmitting four different beams.

[0031] 1A shows an example of a case where only one TRP (TRP1 in this example) of multiple TRPs transmits to the UE (this may be referred to as single mode, single TRP, etc.). In this case, TRP1 transmits both control signals (PDCCH) and data signals (PDSCH) to the UE.

[0032] 1B shows an example of a case where only one TRP (TRP1 in this example) transmits control signals to the UE, and the multi-TRP transmits data signals (also called single master mode). The UE receives each PDSCH transmitted from the multi-TRP based on a single Downlink Control Information (DCI).

[0033] Figure 1C shows an example of a case where each of the multi-TRPs transmits a part of the control signal to the UE, and the multi-TRPs transmit data signals (this may be called a master-slave mode). Part 1 of the control signal (DCI) may be transmitted in TRP1, and Part 2 of the control signal (DCI) may be transmitted in TRP2. Part 2 of the control signal may depend on Part 1. The UE receives each PDSCH transmitted from the multi-TRP based on these parts of the DCI.

[0034] 1D shows an example of a multi-TRP mode in which each TRP transmits a separate control signal to the UE, and the multi-TRP transmits a data signal (also referred to as a multi-master mode). A first control signal (DCI) may be transmitted on TRP1, and a second control signal (DCI) may be transmitted on TRP2. The UE receives each PDSCH transmitted from the multi-TRP based on these DCIs.

[0035] When multiple PDSCHs from multiple TRPs as shown in Figure 1B (which may also be referred to as multiple PDSCHs) are scheduled using one DCI, the DCI may be referred to as a single DCI (S-DCI, single PDCCH). Also, when multiple PDSCHs from multiple TRPs as shown in Figure 1D are scheduled using multiple DCIs, these multiple DCIs may be referred to as multiple DCIs (M-DCI, multiple PDCCHs).

[0036] Each TRP in a multi-TRP may transmit a different transport block (TB) / code word (CW) / different layer, or each TRP in a multi-TRP may transmit the same TB / CW / layer.

[0037] Non-Coherent Joint Transmission (NCJT) is being considered as one form of multi-TRP transmission. In NCJT, for example, TRP1 modulates and layer-maps a first codeword to transmit a first PDSCH using a first number of layers (e.g., two layers) with a first precoding. TRP2 modulates and layer-maps a second codeword to transmit a second PDSCH using a second number of layers (e.g., two layers) with a second precoding.

[0038] Note that multiple PDSCHs (multi-PDSCHs) that are non-coherent may be defined as partially or completely overlapping in time and / or frequency domains, i.e., a first PDSCH from a first TRP and a second PDSCH from a second TRP may overlap in time and / or frequency resources.

[0039] The first PDSCH and the second PDSCH may be assumed to be not quasi-co-located (QCL). Reception of multiple PDSCHs may be interpreted as simultaneous reception of PDSCHs that are not of a certain QCL type (e.g., QCL type D).

[0040] In URLLC for multi-TRP, it is considered that PDSCH (transport block (TB) or codeword (CW)) repetition across multi-TRP is supported. Repetition schemes (URLLC schemes, e.g., Schemes 1, 2a, 2b, 3, and 4) across multi-TRP in the frequency domain, layer (spatial) domain, or time domain are supported. In Scheme 1, multiple PDSCHs from multi-TRP are space division multiplexed (SDM). In Schemes 2a and 2b, PDSCHs from multi-TRP are frequency division multiplexed (FDM). In Scheme 2a, the redundancy version (RV) is the same for multi-TRP. In Scheme 2b, the RVs for multi-TRP may be the same or different. In schemes 3 and 4, multiple PDSCHs from multiple TRPs are time division multiplexed (TDM). In scheme 3, multiple PDSCHs from multiple TRPs are transmitted in one slot. In scheme 4, multiple PDSCHs from multiple TRPs are transmitted in different slots.

[0041] Such a multi-TRP scenario allows for more flexible transmission control using good quality channels.

[0042] NCJT using multiple TRPs / panels may use high rank. To support ideal and non-ideal backhaul between multiple TRPs, both single DCI (single PDCCH, e.g., FIG. 1B) and multiple DCI (multiple PDCCH, e.g., FIG. 1D) may be supported. For both single DCI and multiple DCI, the maximum number of TRPs may be two.

[0043] For single PDCCH design (mainly for ideal backhaul), TCI extension is being considered. Each TCI codepoint in the DCI may correspond to one or two TCI states. The TCI field size may be the same as that of Rel. 15.

[0044] For PDCCH / CORESET specified in Rel. 15, one TCI state without CORESETPoolIndex (also referred to as TRP Info) is set to one CORESET.

[0045] Regarding the PDCCH / CORESET enhancements specified in Rel. 16, in multi-TRP based on multi-DCI, a CORESET pool index is configured for each CORESET.

[0046] (Inter-cell mobility) In NR, one or more transmission / reception points (Transmission / Reception Points (TRPs)) (multi-TRPs (MTRPs)) are considered to perform DL transmission to a UE. Also, it is considered that a UE performs UL transmission to one or more TRPs.

[0047] During inter-cell mobility (e.g., L1 / L2 inter cell mobility), a UE may receive channels / signals from multiple cells / TRPs (see Figures 2A and 2B).

[0048] FIG. 2A illustrates an example of inter-cell mobility (e.g., single-TRP inter-cell mobility) including a non-serving cell. A UE may be configured with one TRP (or single TRP) in each cell. Here, the UE receives channels / signals from the base station / TRP of cell #1, which is the serving cell, and the base station / TRP of cell #3, which is not the serving cell (non-serving cell). For example, this corresponds to a case where the UE switches / switches from cell #1 to cell #3 (e.g., a fast cell switch). The TRP of the serving cell may be referred to as a primary TRP (e.g., pTRP). The TRP of the non-serving cell may be referred to as an additional TRP (aTRP).

[0049] In this case, the selection of the port (e.g., antenna port) / TRP may be performed dynamically or based on the TCI status indicated or updated by the DCI / MAC CE. Here, it is shown that different physical cell ID (e.g., PCI) configurations are supported for cell #1 and cell #3.

[0050] FIG. 2B illustrates an example of a multi-TRP scenario (e.g., multi-TRP inter-cell mobility). A UE may be configured with multiple (e.g., two) TRPs (or different CORESET pool indices) in each cell. Here, the UE receives channels / signals from TRP #1 and TRP #2. Also, here, TRP #1 corresponds to physical cell ID (PCI) #1, and TRP #2 corresponds to PCI #2.

[0051] The multi-TRPs (TRPs #1 and #2) may be connected via an ideal / non-ideal backhaul to exchange information, data, etc. The same or different code words (CWs) and the same or different layers may be transmitted from each TRP of the multi-TRP. As shown in FIG. 2B, non-coherent joint transmission (NCJT) may be used as one form of multi-TRP transmission. This example illustrates the case where NCJT is performed between TPRs corresponding to different PCIs. The same serving cell configuration may be applied / configured for TRPs #1 and #2.

[0052] Multiple PDSCHs (multi-PDSCHs) that are non-coherent may be defined as partially or completely overlapping in time and / or frequency domains. That is, the first PDSCH from TRP #1 and the second PDSCH from TRP #2 may overlap in time and / or frequency resources. The first PDSCH and the second PDSCH may be used for transmission of the same TB or for transmission of different TBs.

[0053] The first PDSCH and the second PDSCH may be assumed to be not quasi-co-located (QCL). Reception of multiple PDSCHs may be interpreted as simultaneous reception of PDSCHs that are not of a certain QCL type (e.g., QCL type D).

[0054] Multiple PDSCHs from multiple TRPs (which may be referred to as multiple PDSCHs) may be scheduled using one DCI (single DCI (S-DCI), single PDCCH) (single master mode). One DCI may be transmitted from one TRP of a multi-TRP. A configuration using one DCI in a multi-TRP may be referred to as single DCI-based multi-TRP (mTRP / MTRP).

[0055] Multiple PDSCHs from a multi-TRP may be scheduled using multiple DCIs (multiple DCI (M-DCI), multiple PDCCHs (multiple PDCCHs)), respectively (multiple master mode). Multiple DCIs may be transmitted from multiple TRPs, respectively. A configuration that utilizes multiple DCIs in a multi-TRP may be referred to as a multi-DCI-based multi-TRP (mTRP / MTRP).

[0056] It may be assumed that the UE transmits separate CSI reports (CSI reports) for different TRPs. Such CSI feedback may be referred to as separate feedback, separate CSI feedback, etc. In this disclosure, "separate" may be interchangeably read as "independent."

[0057] It is assumed that in Rel. 17 NR and later, the MAC CE / DCI will support beam direction to a TCI state associated with a different PCI, and that in Rel. 18 NR and later, the MAC CE / DCI will support direction of a serving cell change to a cell with a different PCI.

[0058] (Timing Advance Group) When multiple TRPs are used, the distances between the UE and each TRP may be different. The multiple TRPs may be included in the same cell (e.g., serving cell). Alternatively, one TRP may correspond to the serving cell and the other TRPs may correspond to non-serving cells. In this case, the distances between each TRP and the UE may be different.

[0059] In existing systems, the transmission timing of an uplink (UL) channel and / or an UL signal (UL channel / signal) is adjusted by a timing advance (TA). The reception timing of the UL channel / signal from different user terminals (UE) is adjusted by a radio base station (TRP: Transmission and Reception Point, also referred to as gNodeB: gNB) side.

[0060] The UE may control the timing of UL transmission by applying timing advance (multiple timing advances) for each pre-configured timing advance group (TAG).

[0061] When multiple timing advances are applied, Timing Advance Groups (TAGs) classified by transmission timing are supported. The UE may control the UL transmission timing for each TAG assuming that the same TA offset (or TA value) is applied to each TAG. In other words, the TA offset may be set independently for each TAG.

[0062] When multiple timing advance is applied, the UE independently adjusts the transmission timing of cells belonging to each TAG, so that even when multiple cells are used, the radio base station can synchronize the reception timing of uplink signals from the UE.

[0063] TAGs (e.g., serving cells belonging to the same TAG) may be configured by higher layer parameters. The same timing advance value may be applied to serving cells belonging to the same TAG. The timing advance group including the SpCell of a MAC entity may be called a Primary Timing Advance Group (PTAG), and the other TAGs may be called Secondary Timing Advance Groups (STAGs).

[0064] In existing systems (e.g., Rel. 16 NR), the configuration of up to four TAGs per cell group (e.g., MCG / SCG) is supported (see Figure 3). Figure 3 shows a case where three TAGs are configured for a cell group including SpCell and SCell #1 to #4. Here, the SpCell and SCell #1 belong to the first TAG (PTAG or TAG #0), SCell #2 and SCell #3 belong to the second TAG (TAG #1), and SCell #4 belongs to the third TAG (TAG #2).

[0065] A timing advance command (TA command) may be notified to the UE using a MAC control element (e.g., MAC CE). The TA command indicates a transmission timing value of an uplink channel and is included in the MAC control element. The TA command is signaled from the radio base station to the UE at the MAC layer. The UE controls a predetermined timer (e.g., a TA timer) based on the reception of the TA command.

[0066] The MAC CE for the timing advance command (TAC MAC CE) may include a field for a timing advance group index (e.g., TAG ID) and a field for the timing advance command (see FIG. 4).

[0067] On the other hand, in future wireless communication systems, it is assumed that different TAGs (or TAG-IDs) are set for one or more TRPs corresponding to a certain cell (or CC). Alternatively, it is assumed that different TRPs corresponding to a certain cell share a common TAG. Alternatively, it is assumed that a MAC CE for a TA command is applied to only one TRP, or that a MAC CE for a TA command is applied to multiple TRPs.

[0068] Alternatively, in inter-cell mobility, it is also envisioned that UL transmission may be controlled based on timing advance for a serving cell (or a TRP of a serving cell) and a non-serving cell (or a TRP of a non-serving cell).

[0069] Thus, in MIMO Rel. 18 and later, it is expected that two timing advances (TAs) for two TRPs will be supported in multi-TRP operation using multi-DCI.

[0070] When TAGs are configured per TRP, a time alignment timer (e.g., timeAlignmentTimer) may be configured for each TRP. The time alignment timer may control when the MAC entity considers a serving cell belonging to the associated TAG to be uplink time aligned. For example, the time alignment timer may be configured by RRC for UL time alignment maintenance.

[0071] A time alignment timer (e.g., timeAlignmentTimer) may be maintained for UL time alignment. In Rel. 17, the time alignment timer (e.g., timeAlignmentTimer) corresponds to each TAG. When the UE receives a MAC CE (e.g., TAC MAC CE) for a timing advance command, it starts or restarts the time alignment timer associated with the indicated timing advance group (e.g., TAG), respectively.

[0072] The MAC entity receives the TAC MAC CE and performs a predetermined value (N ＴＡ ) is maintained, apply a timing advance command for the indicated TAG or start or restart the time alignment timer associated with the indicated TAG. ＴＡ ) may be the timing advance between DL and UL.

[0073] The behavior when the time alignment timer expires may be defined separately for the PTAG and the STAG. Note that the timing advance group (TAG) including the SpCell of the MAC entity may be called the primary timing advance group (PTAG), and the other TAGs may be called secondary timing advance groups (STAGs).

[0074] For example, Rel. 17 supports that when a timing advance timer corresponding to a PTAG expires, a predetermined PTAG action is applied, and when a timing advance timer corresponding to a STAG expires, a predetermined STAG action is applied.

[0075] For example, when the time alignment timer expires, the following actions (e.g., predetermined PTAG action / predetermined STAG action) may be performed.

[0076] Actions for a given PTAG If a time alignment timer is associated with a PTAG: Flush all HARQ buffers for all serving cells. Inform RRC to release PUCCH for all serving cells, if configured. Inform RRC to release SRS, if configured. Clear all configured DL allocations and configured UL allocations. Clear PUSCH resources for semi-persistent CSI reporting. Allow all running time alignment timers to expire. Clear N for all TAGs. ＴＡ Maintain.

[0077] Actions for a given STAG: If a time alignment timer is associated with a STAG, then for all serving cells belonging to that TAG: Flush all HARQ buffers. Inform RRC to release PUCCH, if configured. Inform RRC to release SRS, if configured. Clear all configured DL and UL allocations. Clear PUSCH resources for semi-persistent CSI reporting. Clear N for that TAG.ＴＡ Maintain.

[0078] <TA Control for Each TRP / Panel> As described above, when communication is performed using a plurality of transmission / reception points (for example, TRPs) / panels, it is also possible to control the timing advance for each TRP / panel.

[0079] For example, TA may be applied for each TRP (or TRP TA unit indication may be performed). For example, at least one of the following options may be applied:

[0080] [Option 1] A different TAG-ID may be set for each TRP, and a different MAC CE for the TA command may be set for each TRP. Each TAG may maintain a time alignment timer for UL time alignment.

[0081] [Option 2] Different TRPs may share a TAG. The MAC CE for the TA command may apply to only one TRP. The UE may apply different TAs to other TRPs. For example, the UE may adjust the TA value for other TRPs (e.g., TRP#1) by a TA offset (TA_TRP_offset) based on the TA for TRP#0 (TA_TRP#0).

[0082] In this case, there may be only one time alignment timer for UL time alignment of multiple TRPs, which may mean that UL time alignment of multiple TRPs is maintained or lost simultaneously.

[0083] [Option 3] There may be one TAG, and the MAC CE for the TA command may apply to multiple serving TRPs for the UE.

[0084] [Option 4] There may be a single TAG. MAC CEs for TA commands received on a TRP / CW / PDSCH / DMRS port group may apply to the same TRP / CW / PDSCH / DMRS port group of the TAG. Each TRP / CW / PDSCH / DMRS port group of the TAG maintains a time alignment timer for UL time alignment.

[0085] (Analysis 1) Assume that multiple (e.g., two) TRPs of a serving cell belong to different TAGs. In Rel. 17, the TAG including the SpCell of the MAC entity corresponds to the PTAG, and the other TAGs correspond to the STAG. In addition, the behavior when the time alignment timer expires is defined differently for the PTAG and the STAG.

[0086] However, in Rel. 18 and later, it is possible that two TRPs of an SpCell belong to different TAGs (e.g., TAG ID #0 and TAG ID #1) (see FIG. 5). In such a case, the issue is how to control the operation based on the time alignment timer of each TAG (e.g., the operation when the time alignment timer expires).

[0087] 5 shows a case where the TRP #0 of the SpCell and the TRP #0 of the SCell #1 belong to the same TAG group (TAG ID #0), and the TRP #1 of the SpCell and the TRP #1 of the SCell #1 belong to the same TAG group (TAG ID #1). In this case, the question arises as to which TAG corresponds to the PTAG, or how to control the UE operation in each TAG when the time alignment timer expires.

[0088] (Analysis 2) Assume that multiple (e.g., two) TRPs of a serving cell belong to the same TAG, and a timing advance command MAC CE (TAC MAC CE) is applied / indicated to only one TRP. For example, a UE may apply the TAC MAC CE to only one TRP to adjust the timing advance (e.g., TA_0) of that TRP, and adjust / control the timing advance (e.g., TA_1) of the other TRPs using an offset based on TA_0. TA_1 may be obtained, for example, by TA_0 + offset. The offset may be indicated to the UE by the base station using RRC / MAC CE / DCI.

[0089] In this case, the question is whether to support a time alignment timer for each TRP, or whether to start / restart the timer based on an offset indication.

[0090] (Analysis 3) Assume that multiple (e.g., two) TRPs of a serving cell belong to the same TAG and the TAC is indicated for each TRP by the timing advance command MAC CE (TAC MAC CE). In this case, each TRP maintains its own time alignment timer.

[0091] In such a case, the problem arises as to how to control the UE operation for each TRP when the time alignment timer expires.

[0092] (Analysis 4) Assume that multiple (e.g., two) TRPs of a serving cell belong to the same TAG and the TAC is indicated for each TRP by the timing advance command MAC CE (TAC MAC CE). In this case, each TRP maintains its own time alignment timer.

[0093] In such a case, the question arises as to whether multiple TRPs from multiple cells can share the same TA command / same time alignment timer, and if so, how to configure the TAG.

[0094] The inventors focused on analyses 1 to 4 when using multiple TRPs / panels, and considered controlling the timing advance for at least one of analyses 1 to 4 (e.g., adjusting the timing advance / setting a TAG / operation based on a timing advance timer, etc.), and came up with the present embodiment.

[0095] 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.

[0096] In the present disclosure, "A / B" may mean "at least one of A and B" or may be read as A and B, or A or B. In the present disclosure, "A / B / C" may mean "at least one of A, B, and C" or may be read as A, B and C, or A, B, or C.

[0097] In the present disclosure, cell, serving cell, CC, carrier, BWP, DL BWP, UL BWP, active DL BWP, active UL BWP, and band may be interchangeable. In the present disclosure, index, ID, indicator, and resource ID may be interchangeable. In the present disclosure, support, control, controllable, operate, and operable may be interchangeable.

[0098] In the present disclosure, the terms configure, activate, update, indicate, enable, specify, and select may be read interchangeably.

[0099] In the present disclosure, the higher layer signaling may be, for example, any one of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, etc., or a combination thereof. In the present disclosure, RRC, RRC signaling, RRC parameters, higher layer, higher layer parameters, RRC information elements (IEs), and RRC messages may be read interchangeably.

[0100] The MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), etc. The broadcast information may be, for example, a Master Information Block (MIB), a System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.

[0101] In the present disclosure, panel, beam, spatial domain filter, spatial setting, TCI state, UL TCI state, unified TCI state, unified beam, common TCI state, common beam, TCI assumption, QCL assumption, QCL parameters, spatial domain receive filter, UE spatial domain receive filter, UE receive beam, DL beam, DL receive beam, DL precoding, DL precoder, DL-RS, RS of QCL type D for TCI state / QCL assumption, RS of QCL type A for TCI state / QCL assumption, spatial relationship, spatial domain transmit filter, UE spatial domain transmit filter, UE transmit beam, UL beam, UL transmit beam, UL precoding, UL precoder, and PL-RS may be read interchangeably. In the present disclosure, QCL type X-RS, DL-RS associated with QCL type X, DL-RS having QCL type X, source of DL-RS, SSB, CSI-RS, and SRS may be read interchangeably.

[0102] In the present disclosure, panel, Uplink (UL) transmitting entity, TRP, spatial relationship, control resource set (CONTROLLER RESOLUTION SET (CORESET)), PDSCH, codeword, base station, antenna port of a certain signal (e.g., Demodulation Reference Signal (DMRS) port), antenna port group of a certain signal (e.g., DMRS port group), group for multiplexing (e.g., Code Division Multiplexing (CDM) group, reference signal group, CORESET group), CORESET pool, CORESET subset, CW, redundancy version (RV), layer (MIMO layer, transmission layer, spatial layer) may be interchangeable. Also, panel identifier (ID) and panel may be interchangeable. In the present disclosure, the terms TRP ID, TRP Associated ID, CORESET Pool Index, the position of one of two TCI states corresponding to one code point of a field in a DCI (ordinal number, first TCI state or second TCI state), and TRP may be read interchangeably.

[0103] In the present disclosure, panel, UE panel, RS port group, DMRS port group, SRS port group, RS resource group, DMRS resource group, SRS resource group, beam group, TCI state group, spatial relationship group, SRS resource indicator (SRI) group, antenna port group, antenna group, and CORESET group may be read as interchangeable.

[0104] The panel may be associated with at least one of a panel ID, a UL TCI state, a UL beam, a DL beam, a DL RS resource, and spatial relationship information.

[0105] In the present disclosure, the terms "multi-TRP," "multi-TRP system," "multi-TRP transmission," "multi-PDSCH," "channel using multi-TRP," "channel using multiple TCI states / spatial relationships," "multi-TRP being enabled by RRC / DCI," "multiple TCI states / spatial relationships being enabled by RRC / DCI," and "at least one of multi-TRP based on a single DCI" and "multi-TRP based on multiple DCI" may be interchangeable. In the present disclosure, the terms "multi-TRP based on multiple DCI," and "setting a CORESET pool index (CORESETPoolIndex) value of 1 for the CORESET" may be interchangeable. In the present disclosure, the terms "multi-TRP based on a single DCI," and "at least one code point in the TCI field is mapped to two TCI states" may be interchangeable.

[0106] In the present disclosure, the terms single TRP, single DCI, single PDCCH, multi-TRP based on single DCI, single TRP system, single TRP transmission, single PDSCH, channel using single TRP, channel using one TCI state / spatial relationship, multi-TRP not being enabled by RRC / DCI, multiple TCI states / spatial relationships not being enabled by RRC / DCI, a CORESETPoolIndex value of 1 not being set for any CORESET and no code point in the TCI field being mapped to two TCI states, and two TCI states on at least one TCI code point being activated may be read interchangeably.

[0107] In the present disclosure, TRP#1 (first TRP) may correspond to CORESET pool index = 0 or may correspond to the first of two TCI states corresponding to one code point in the TCI field, and TRP#2 (second TRP) may correspond to CORESET pool index = 1 or may correspond to the second of two TCI states corresponding to one code point in the TCI field.

[0108] In addition, in the present disclosure, signaling configuration, signaling, setting, configuration, setting information, instruction, instruction information, etc. may be read interchangeably.

[0109] (Wireless communication method) At least one of information about a TRP corresponding to a serving cell and information about a TAG corresponding to each TRP may be configured / notified to a UE from a base station.

[0110] The base station may configure the UE with at least one of information about the TRPs included in the serving cell and information about the TAGs corresponding to each TRP using RRC parameters. Alternatively, the base station may configure the UE with at least one of information about the TRPs included in the serving cell and information about the TAGs corresponding to each TRP using MAC CE. Alternatively, the base station may configure the UE with information about the TRPs included in the serving cell using RRC parameters and notify the UE of information about the TAGs corresponding to each TRP using MAC CE.

[0111] The UE controls the UL transmission timing (e.g., adjusts the timing advance) corresponding to each TRP by taking into account the TAG to which the TRPs corresponding to the serving cell belong. The UE may control the timing advance based on the time alignment timer corresponding to each TRP.

[0112] In addition, when multiple timing advance timers corresponding to multiple TRPs are configured, the UE may determine / control its operation after the timing advance timer expires based on the number of timing advance timers that expire simultaneously, the type of TAG in which the timing advance timer expires (PTAG or STAG), and the type of cell included in the TAG in which the timing advance timer expires (e.g., whether an SpCell is included or not).

[0113] <First embodiment> In the first embodiment, the timing advance control when multiple (for example, two) TRPs of a serving cell belong to different TAGs will be described. Note that the first embodiment may be suitably applied to the configuration shown in the above analysis 1. Of course, the case where the first embodiment is applied is not limited to this.

[0114] If the TAGs to which two TRPs of a serving cell belong are separately configurable, the time alignment timer may be configured / maintained for each TAG. Also, the two TRPs (e.g., TRP#0 and TRP#1) may correspond to different CORESET pool indices (e.g., {0, 1}).

[0115] The TAG (e.g., PTAG / STAG or TAG ID) to which the multiple TRPs of each serving cell belong may be defined / configured based on a predetermined condition, which may be at least one of the following: cell type / cell index (e.g., SPCell or SCell), TRP index (e.g., TRP#0 or TRP#1), and a combination of cell type / cell index and TRP index.

[0116] At least one of the following options 1-1 to 1-4 may be applied to configure the TAG to which multiple TRPs of each serving cell belong.

[0117] [Option 1-1] A TAG including a TRP of a specific cell may be defined / set as a PTAG.

[0118] For example, a TAG including TRP#0 of the SpCell of the MAC entity may be defined / configured as a PTAG. When the time alignment timer of the TAG expires, the UE may apply a predetermined operation for the PTAG.

[0119] In the present disclosure, the predetermined PTAG operation may be, for example, an operation applied when a time alignment timer for a PTAG defined in Rel. 17 expires. However, the present disclosure is not limited to this, and the predetermined PTAG operation may be, for example, an operation applied when a time alignment timer for a PTAG defined in Rel. 18 or later expires.

[0120] In addition, a TAG including TRP#1 of the SpCell of the MAC entity may also be defined / configured as a PTAG (see FIG. 6). When the time alignment timer of the TAG expires, the UE may apply a predetermined operation for the PTAG.

[0121] In this case, a cell group (e.g., MCG / SCG) may support the existence of multiple (e.g., two) PTAGs or the definition / configuration of multiple PTAGs. Also, a TAG that does not include a TRP of the SpCell may be defined / configured as an STAG.

[0122] [Option 1-2] A TAG including a specific TRP of a specific cell may be defined / set as a PTAG. Also, a TAG including a TRP other than the specific TRP of a specific cell may be defined / set as a STAG.

[0123] For example, a TAG including a TRP with a specific index (e.g., TRP #0) of an SpCell of a MAC entity may be defined / configured as a PTAG. When the time alignment timer of the TAG expires, the UE may apply a predetermined PTAG operation.

[0124] On the other hand, a TAG including a TRP (e.g., TRP #1) with an index other than the specific index of the SpCell of the MAC entity may be defined / configured as a STAG (see Fig. 7A). When the time alignment timer of the TAG expires, the UE may apply a predetermined STAG-specific operation.

[0125] In the present disclosure, the predetermined STAG operation may be, for example, an operation applied when a time alignment timer for a STAG defined in Rel. 17 expires. However, the present disclosure is not limited to this, and the predetermined STAG operation may be, for example, an operation applied when a time alignment timer for a STAG defined in Rel. 18 or later expires.

[0126] Here, the case where a TAG including TRP#0 of the SpCell is defined / set as a PTAG and a TAG including TRP#1 of the SpCell is defined / set as a STAG is shown, but this is not limited to this. For example, a TAG including TRP#0 of a specific cell may be defined / set as a STAG, and a TAG including TRP#1 may be defined / set as a PTAG (see FIG. 7B).

[0127] In this case, a cell group (e.g., MCG / SCG) may support the existence of a single PTAG or the definition / configuration of a single PTAG. Also, a TAG that does not include a specific TRP of the SpCell may be defined / configured as a STAG.

[0128] [Option 1-3] The TAG including which TRP of the SpCell is referred to as the PTAG may be configured. For example, information about the TRP corresponding to the PTAG may be configured / notified to the UE from the base station using RRC / MAC CE, etc.

[0129] In this case, a restriction may be added that only one TRP can be set as a PTAG, or multiple (e.g., two) TRPs may be set as PTAGs without any restriction on the TRPs that can be set as PTAGs.

[0130] If a TRP is configured as a PTAG, the UE may apply PTAG-specific behavior (e.g., behavior for a given PTAG after the time alignment timer expires), otherwise the UE may apply STAG-specific behavior (e.g., behavior for a given STAG after the time alignment timer expires).

[0131] Alternatively, which TAG is to be referred to as the PTAG may be configured in the UE by the base station. For example, information regarding the TAG corresponding to the PTAG may be configured / notified to the UE by the base station using RRC / MAC CE or the like.

[0132] In this case, a restriction may be added that the number of tags that can be set as PTAGs in each cell group (for example, MCG / SCG) is a predetermined number or less (for example, only one).

[0133] Alternatively, the number of tags that can be set as a PTAG may not be limited, and multiple tags (for example, two) may be set as a PTAG.

[0134] [Option 1-4] If multiple TRPs corresponding to an SpCell belong to different TAGs, a new operation may be defined / applied as the operation after the time alignment timer corresponding to each TAG expires.

[0135] <<Application to SpCell>> Assume that two time alignment timers are set / applied to two TAGs each including two TRPs of the SpCell (see Figure 8). Figure 8 shows a case where a time alignment timer is set separately for TAG #0 including TRP #0 and SCell #1 of the SpCell, and for TAG #1 including TRP #1 and SCell #2 of the SpCell.

[0136] In this case, the UE may determine / control its operation after the timing advance timer expires based on at least one of the following: the number of timing advance timers that expire simultaneously, the type of TAG in which the timing advance timer expires (PTAG or STAG), and the type of cell included in the TAG in which the timing advance timer expires (e.g., whether an SpCell is included or not).

[0137] A predetermined PTAG operation may be applied only when both the time alignment timers corresponding to TAG #0 and TAG #1 have expired. In this case, the UE may control the application of the predetermined PTAG operation to both TAG #0 and TAG #1.

[0138] In addition, when both TAG#0 and TAG#1 are PTAGs, a specified PTAG operation may be applied, and when one of TAG#0 and TAG#1 is a PTAG and the other is a STAG, a specified PTAG operation may be applied to the PTAG, and a specified STAG operation may be applied to the STAG.

[0139] When one of two time alignment timers has expired and the other is running, a predetermined STAG action may be applied to the TAG whose time alignment timer has expired. For example, when the time alignment timer corresponding to TAG#0 (e.g., PTAG) has expired and the time alignment timer corresponding to TAG#1 (e.g., STAG) is running, a predetermined STAG action may be applied to TAG#0 (e.g., PTAG).

[0140] That is, if one of the two time alignment timers has expired and the other is running, a specific STAG action may be applied regardless of the TAG type (PTAG or STAG).

[0141] Alternatively, in a serving cell, if a time alignment timer corresponding to one TRP has expired and a time alignment timer corresponding to another TRP is running, the operation for a specific TAG (PTAG / STAG) may not be applied to a specific serving cell (e.g., SpCell).

[0142] In this case, the TRP whose time alignment timer has expired may be considered as unsynchronized, and a random access operation (e.g., RACH procedure) may be initiated for synchronization.

[0143] A configuration may be adopted in which a predetermined TAG (PTAG / STAG) operation is not applied to a specific cell (e.g., SpCell). For example, in FIG. 8, when the time alignment timer corresponding to TAG #0 has expired and the time alignment timer corresponding to TAG #1 is running, a predetermined STAG operation may be applied to SCell #1, but not to the SpCell. Also, when the time alignment timer corresponding to TAG #1 has expired and the time alignment timer corresponding to TAG #0 is running, a predetermined STAG operation may be applied to SCell #2, but not to the SpCell.

[0144] <<Application to SCell>> Assume that two time alignment timers are configured / applied to two TAGs each including two TRPs of the SCell (see Figure 9). Figure 9 shows a case where a time alignment timer is configured separately for TAG #0 including TRP #0 and SpCell of SCell #1, and for TAG #1 including TRP #1 and SCell #2 of SCell #1.

[0145] When one of the two time alignment timers has expired and the other is running, the operation related to the TAG may be controlled based on whether a particular cell (e.g., SpCell) is included in the TAG whose time alignment timer has expired.

[0146] For example, if the TAG whose time alignment timer has expired includes an SpCell, a predetermined PTAG operation may be applied, whereas if the TAG whose time alignment timer has expired does not include an SpCell, a predetermined STAG operation may be applied.

[0147] Alternatively, if the time alignment timer for one TRP in the serving cell has expired and the time alignment timer for another TRP is running, the operation for a given TAG (PTAG / STAG) may not be applied. In this case, the TRP whose time alignment timer has expired is considered as unsynchronized, and a random access operation (e.g., RACH procedure) may be initiated for synchronization.

[0148] For example, in Figure 9, if the time alignment timer corresponding to TAG #0 is running and the time alignment timer corresponding to TAG #1 has expired, a specified STAG operation may be applied to SCell #2, but not to SCell #1.

[0149] Inter-cell scenario In L1 / L2 inter-cell operation, the first embodiment may be applied.

[0150] For example, the first embodiment may be applied to a case where up to M physical cell IDs (e.g., PCIs) are set / applied per CC for an activated TCI state (e.g., a case where M=2 in a multi-TRP inter-cell operation using multi-DCI). For example, in Option 1-1 to Option 1-4, "TRP" may be replaced with "PCI" and applied.

[0151] The M PCIs of the serving cell may belong to different TAGs. In this case, the following options 1-1' to 1-4' may be applied. M may be 2 or a value greater than 2.

[0152] [Option 1-1'] A TAG including the PCI of the SpCell of the MAC entity may be defined / configured as a PTAG. If the time alignment timer of the TAG expires, the UE may apply the behavior for the specific PTAG. This may mean that there are multiple PTAGs in a cell group (e.g., MCG / SCG).

[0153] [Option 1-2'] A TAG including the PCI of the SpCell of the MAC entity may be defined / configured as a PTAG. When the time alignment timer of the TAG expires, the UE may apply a predetermined PTAG behavior.

[0154] On the other hand, a TAG including other PCIs (e.g., additional PCIs) of the SpCell of the MAC entity may be defined / configured as a STAG, and the UE may apply a predetermined STAG-specific action when the time alignment timer of the STAG expires.

[0155] [Option 1-3'] It may be configured which TAG containing which PCI of the SpCell is referred to as the PTAG.

[0156] In this case, a restriction may be added that only one of the PCIs (or a maximum of N PCIs) can be set as a PTAG. Alternatively, no restriction may be placed on the PCIs that can be set as a PTAG, and multiple PCIs (for example, any number of PCIs) may be allowed to be set as a PTAG.

[0157] If a PCI is configured as a PTAG, the UE may apply PTAG-specific behavior (e.g., behavior for a given PTAG after the time alignment timer expires), otherwise the UE may apply STAG-specific behavior (e.g., behavior for a given STAG after the time alignment timer expires).

[0158] The base station may configure the UE with a tag to be referred to as a PTAG. In this case, a restriction may be added that the number of tags that can be configured as PTAGs in each cell group (e.g., MCG / SCG) is limited to a predetermined number or less (e.g., only one or a maximum of N).

[0159] Alternatively, the number of tags that can be set as PTAGs may not be limited, and multiple tags (for example, two or any number) may be set as PTAGs.

[0160] [Options 1-4'] New actions may be defined / applied as actions for TAGs (eg, PTAG / STAG) related to the time alignment timer.

[0161] <Application to SpCell> It is assumed that a plurality of time alignment timers are set / applied to an SpCell for a plurality of TAGs each including a plurality of PCIs of the SpCell.

[0162] In this case, the UE may apply the action for a given PTAG only if all time alignment timers have expired.

[0163] If one of the multiple time alignment timers expires while other time alignment timers are running, a predetermined STAG-specific action may be applied to the TAG whose time alignment timer expired.

[0164] Alternatively, if a time alignment timer corresponding to one PCI in a serving cell expires and a time alignment timer corresponding to another PCI is running, the operation for a specific TAG (PTAG / STAG) may not be applied to the serving cell (e.g., SPCell). In this case, the PCI whose time alignment timer expired is considered to be unsynchronized, and a random access operation (e.g., RACH procedure) may be initiated for synchronization. This operation may be applied to an SCell when multiple PCIs of the SCell are included in multiple TAGs.

[0165] <Second embodiment> In the second embodiment, the timing advance control when multiple (for example, two) TRPs of a serving cell belong to the same TAG will be described. Note that the second embodiment may be suitably applied to the configuration shown in the above analysis 2. Of course, the case where the second embodiment is applied is not limited to this.

[0166] If two TRPs of a serving cell belong to the same TAG, the MAC CE for the TA command may be indicated / applied to only one TRP. For example, the MAC CE for the TA command may be indicated / applied to TRP#0. The timing advance applied to TRP#0 may be called TA_0.

[0167] For other TRPs (e.g., TRP #1), the UE may adjust the timing advance using an offset relative to TA_0. The timing advance applied to TRP #1 may be called TA_1. For example, TA_1 may be defined as TA_0 = TA_0 + offset. Information about the offset may also be notified to the UE by the base station.

[0168] In this case, the timing advance timer may be set / applied to each TRP in common or separately. The UE may adjust / control the timing advance by applying at least one of the following options 2-1 to 2-2.

[0169] [Option 2-1] Two TRPs may share one time alignment timer (see FIG. 10A). When a UE receives an offset instruction (or information about an offset), it may not affect the time alignment timer (Alt. 2-1-1). For example, even if the UE receives information about an offset while the time alignment timer is running, it may continue to apply the time alignment timer (without resetting it) and not reflect the offset content. In this case, the time alignment timer may expire, and the offset may be reflected in the time alignment timer applied thereafter.

[0170] Alternatively, when the UE receives an offset instruction (or information about the offset), it may control the time alignment timer to start / restart / reset (Alt. 2-1-2). In this case, it becomes possible to flexibly change the timing advance for TRP#1.

[0171] In addition, when a time alignment timer commonly set / applied to TRPs expires, a predetermined PTAG operation may be applied.

[0172] [Option 2-2] A first time alignment timer may be applied / maintained for the TPR (e.g., TRP#0) whose TA is adjusted by the MAC CE for TA command. The first time alignment timer may be, for example, a time alignment timer supported by the existing system (e.g., Rel. 17 / Rel. 16).

[0173] On the other hand, a second time alignment timer may be applied / maintained for the TRP (e.g., TRP #1) whose TA is adjusted by the offset (see FIG. 10B). The second time alignment timer may be a new timer.

[0174] When the UE receives an indication of the offset (or information about the offset), it may control to start / restart / reset a new timer. If the new timer expires, the TRP (e.g., TRP #1) may be considered as unsynchronized. In this case, the UE may control to initiate a random access operation (e.g., RACH procedure) for synchronization.

[0175] Inter-cell scenario In L1 / L2 inter-cell operation, the second embodiment may be applied.

[0176] For example, the second embodiment may be applied to a case where up to M physical cell IDs (e.g., PCIs) are configured / applied per CC for an activated TCI state (e.g., a case where M=2 in a multi-TRP inter-cell operation using multi-DCI). For example, in Option 2-1 to Option 2-2, "TRP" may be replaced with "PCI," "2TRP / PCI" may be replaced with "multiple (e.g., 2 or more) PCIs," "TRP#0" may be replaced with "serving PCI," and "TRP#1" may be replaced with "other PCIs / additional PCIs."

[0177] <Third embodiment> In the third embodiment, a description will be given of timing advance control in the case where multiple (for example, two) TRPs of a serving cell belong to the same TAG and the MAC CE for TA command indicates a TAC for each TRP (or a TAC for each TRP). Note that the third embodiment may be suitably applied to the configuration shown in the above analysis 3. Of course, the case in which the third embodiment is applied is not limited to this.

[0178] If two TRPs (e.g., TRP#0 and TRP#1) of a serving cell belong to the same TAG (e.g., TAG#0), the MAC CE for TAC may indicate a per-TRP TAC (e.g., a per-TRP TAC), and each TRP may maintain its own time alignment timer (see Figure 11).

[0179] In this case, the UE may determine / control its operation after the timing advance timer expires based on at least one of the following: the number of timing advance timers that expire simultaneously, the type of TAG in which the timing advance timer expires (PTAG or STAG), and the type of cell included in the TAG in which the timing advance timer expires (e.g., whether an SpCell is included or not).

[0180] For two time alignment timers of two TRPs, if both of the two time alignment timers expire, the UE may apply a specified TAG operation (e.g., a specified PTAG / specified STAG operation) to TAG #0.

[0181] If one of the two time alignment timers has expired and the other is running, the UE may apply at least one of the following options 3-1 to 3-2.

[0182] [Option 3-1] The UE may control the TAG (e.g., TAG #0) containing the TRP whose time alignment timer has expired to apply a specified TAG operation (e.g., operation for a specified PTAG).

[0183] In this case, even if TAG #0 includes a TRP whose time alignment timer has not yet expired, a predetermined PTAG operation may be applied to the TAG. In other words, if the time alignment timer of at least one TRP included in the TAG expires, a predetermined PTAG operation may be applied to the TAG (or multiple TRPs included in the TAG). Note that Option 3-1 may be applied if the time alignment timer of a specific TRP among the TRPs included in the TAG expires.

[0184] [Option 3-2] The UE may control not to apply a predetermined TAG operation (e.g., a predetermined PTAG operation) to a TAG (e.g., TAG #0) including a TRP whose time alignment timer has expired. In other words, if at least one TRP included in the TAG is running, the predetermined PTAG operation may not be performed.

[0185] The UE may control not to perform a predetermined PTAG operation if a TAG includes a TRP whose time alignment timer has not yet expired. In this case, only the TRP whose time alignment timer has expired is considered to be asynchronous (or not synchronized), and RACH operation may be initiated to synchronize the TRP.

[0186] Variations Different options may be applied in different cases.

[0187] Different options may be applied when the time alignment timer for TRP#0 has expired and the time alignment timer for TRP#1 is running (Case 3-1A) and when the time alignment timer for TRP#1 has expired and the time alignment timer for TRP#0 is running (Case 3-2A). For example, option 3-1 may be applied to case 3-1A, and option 3-2 may be applied to case 3-2A.

[0188] Also, different options may be applied when the TAG is a PTAG (case 3-1B) and when the TAG is a STAG (case 3-2B).

[0189] In addition, different options may be applied when the serving cells of the two TRPs are SpCells (Case 3-1C) and when the serving cells of the two TRPs are SCells (Case 3-2C).

[0190] If multiple TRPs in multiple cells can share the same time alignment timer, when the time alignment timer expires, all TRPs sharing the same time alignment timer may be considered to be asynchronous.

[0191] Inter-cell scenario The third embodiment may be applied in L1 / L2 inter-cell operation.

[0192] For example, the third embodiment may be applied to a case where up to M physical cell IDs (e.g., PCIs) are configured / applied per CC for an activated TCI state (e.g., a case where M=2 in a multi-TRP inter-cell operation using multi-DCI). For example, in the third embodiment, "TRP" may be replaced with "PCI," "2TRP / PCI" may be replaced with "multiple (e.g., 2 or more) PCIs," "TRP#0" may be replaced with "serving PCI," and "TRP#1" may be replaced with "other PCIs / additional PCIs."

[0193] <Fourth embodiment> In the fourth embodiment, a description will be given of timing advance control in the case where multiple (for example, two) TRPs of a serving cell belong to the same TAG and a MAC CE for TA command indicates a TAC for each TRP. Note that the fourth embodiment may be suitably applied to the configuration shown in the above analysis 4. Of course, the case in which the fourth embodiment is applied is not limited to this.

[0194] If two TRPs of a serving cell belong to the same TAG, the MAC CE for TAC may indicate the TAC for each TRP. Each TRP may maintain its own time alignment timer.

[0195] It may be supported that multiple TRPs from multiple cells share the same TA command / same time alignment timer. In this case, sub-TAGs (e.g., sub-TAGs) may be defined. One or more sub-TAGs may be included in one TAG. TRPs belonging to the same sub-TAG may share the same TA command / same time alignment timer.

[0196] The tag to which the sub-tag is set may be limited to a specific type of tag (e.g., a PTAG), or the tag to which the sub-tag is set may be set regardless of the tag type (both a PTAG and a STAG).

[0197] If sub-TAG is supported, the UE may apply at least one of the following options 4-1 to 4-2.

[0198] [Option 4-1]

[0199] Based on the TRP index, the TRPs belonging to the sub-TAG may be determined.

[0200] For example, TRP#0 of all serving cells in the same TAG may share the same TA command / same time alignment timer, and the TRP#0 may belong to the same sub-TAG. Also, TRP#1 of all serving cells in the same TAG may share the same TA command / same time alignment timer, and the TRP#1 may belong to the same sub-TAG (see Figure 12). Figure 12 may be the default configuration.

[0201] For a serving cell that does not have multiple TRPs (or multiple CORESET pool indices) configured, by default the serving cell may be configured to share the same TA command / same time alignment timer as a specific TRP (e.g., TRP #0) and belong to the same TAG as the specific TRP (e.g., TRP #0).

[0202] [Option 4-2] The base station may use RRC / MAC CE to configure which TRPs share the same TA command / same time alignment timer, and the base station may use RRC / MAC CE to configure which TRPs belong to which sub-TAG.

[0203] For a serving cell where multi-TRP is not configured, the serving cell may share the same TA command / same time alignment timer where TRP may be configured and may belong to a TAG where sub-TAG may be configured.

[0204] Inter-cell scenario The third embodiment may be applied in L1 / L2 inter-cell operation.

[0205] For example, the fourth embodiment may be applied to a case where up to M physical cell IDs (e.g., PCIs) are configured / applied per CC for an activated TCI state (e.g., a case where M=2 in a multi-TRP inter-cell operation using a multi-DCI). For example, in the fourth embodiment, "TRP" may be replaced with "PCI," "2TRP / PCI" may be replaced with "multiple (e.g., 2 or more) PCIs," "TRP#0" may be replaced with "serving PCI," "TRP#1" may be replaced with "other PCI / additional PCI," "M-TRP is not configured" may be replaced with "multiple PCIs are not configured (or inter-cell operation is not configured)," or "M-TRP is not configured" may be replaced with "only one PCI is configured."

[0206] <UE Capability Information> In the first to fourth embodiments, the following UE capabilities may be set. Note that the following UE capabilities may be interpreted as parameters (e.g., upper layer parameters) set in the UE from a network (e.g., a base station).

[0207] UE capability information regarding whether different TAs are supported for two TRPs of a serving cell may be defined.

[0208] UE capability information regarding the maximum number of different TAs supported in all serving cells may be defined.

[0209] The first to fourth embodiments may be applied to a UE that supports / reports at least one of the above-mentioned UE capabilities, or may be applied to a UE configured by the network.

[0210] (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.

[0211] 13 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).

[0212] 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.

[0213] In EN-DC, the LTE (E-UTRA) base station (eNB) is the master node (Master Node (MN)), and the NR base station (gNB) is the secondary node (Secondary Node (SN)). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0214] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity in which both the MN and SN are NR base stations (gNBs) (NR-NR Dual Connectivity (NN-DC))).

[0215] 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.

[0216] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using multiple component carriers (CCs) and dual connectivity (DC).

[0217] Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band higher than 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a higher frequency band than FR2.

[0218] 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.

[0219] The multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with the Common Public Radio Interface (CPRI), an X2 interface, etc.) or wirelessly (e.g., NR communication). For example, when NR communication is used as a backhaul between the base stations 11 and 12, the base station 11 corresponding to the upper station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0220] 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.

[0221] The user terminal 20 may be a terminal that supports at least one of communication methods such as LTE, LTE-A, and 5G.

[0222] An Orthogonal Frequency Division Multiplexing (OFDM)-based radio access scheme may be used in the wireless communication system 1. For example, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), or the like may be used in at least one of the downlink (DL) and uplink (UL).

[0223] The radio access scheme may also be called a waveform. Note that in the wireless communication system 1, other radio access schemes (e.g., other single-carrier transmission schemes, other multi-carrier transmission schemes) may be used as the UL and DL radio access schemes.

[0224] 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.

[0225] Furthermore, in the wireless communication system 1, an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), a random access channel (Physical Random Access Channel (PRACH)), or the like may be used as an uplink channel.

[0226] The PDSCH transmits user data, higher layer control information, a System Information Block (SIB), etc. The PUSCH may transmit user data, higher layer control information, etc. Furthermore, the PBCH may transmit a Master Information Block (MIB).

[0227] 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.

[0228] Note that the DCI for scheduling the PDSCH may be referred to as a DL assignment, a DL DCI, etc., and the DCI for scheduling the PUSCH may be referred to as a UL grant, a UL DCI, etc. Note that the PDSCH may be replaced with DL data, and the PUSCH may be replaced with UL data.

[0229] A control resource set (CORESET) and a search space may be used to detect the PDCCH. The CORESET corresponds to resources for searching for DCI. The search space corresponds to a search region and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor the CORESET associated with a certain search space based on the search space configuration.

[0230] One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be referred to as a search space set. Note that the terms "search space," "search space set," "search space configuration," "search space set configuration," "CORESET," "CORESET configuration," and the like in the present disclosure may be read interchangeably.

[0231] The PUCCH may transmit uplink control information (UCI) including at least one of channel state information (CSI), delivery confirmation information (which may be called, for example, Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). The PRACH may transmit a random access preamble for establishing a connection with a cell.

[0232] 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.

[0233] In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), etc. may be transmitted. In the wireless communication system 1, as the DL-RS, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), a demodulation reference signal (DMRS), a positioning reference signal (PRS), a phase tracking reference signal (PTRS), etc. may be transmitted.

[0234] The synchronization signal may be, for example, at least one of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). A signal block including an SS (PSS, SSS) and a PBCH (and a DMRS for the PBCH) may be referred to as an SS / PBCH block, an SS Block (SSB), or the like. Note that the SS, SSB, and the like may also be referred to as a reference signal.

[0235] Furthermore, in the wireless communication system 1, a sounding reference signal (SRS), a demodulation reference signal (DMRS), or the like may be transmitted as an uplink reference signal (UL-RS). Note that the DMRS may also be called a user equipment-specific reference signal (UE-specific reference signal).

[0236] 14 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.

[0237] 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.

[0238] 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.

[0239] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may control transmission and reception using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140, measurement, etc. The control unit 110 may generate data, control information, sequences, etc. to be transmitted as signals, and transfer them to the transceiver unit 120. The control unit 110 may perform call processing (setting up, releasing, etc.) of communication channels, status management of the base station 10, management of radio resources, etc.

[0240] 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.

[0241] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or may be configured from a transmitting unit and a receiving unit. The transmitting unit may be configured from a transmission processing unit 1211 and an RF unit 122. The receiving unit may be configured from a reception processing unit 1212, the RF unit 122, and a measurement unit 123.

[0242] The transmitting and receiving antenna 130 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0243] 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.

[0244] The transceiver 120 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0245] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (e.g., RLC retransmission control), Medium Access Control (MAC) layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 110, and generate a bit string to be transmitted.

[0246] The transmitter / receiver unit 120 (transmission processing unit 1211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, Discrete Fourier Transform (DFT) processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0247] The transceiver unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 130.

[0248] 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 130.

[0249] 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.

[0250] 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.

[0251] 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.

[0252] The transmitter and receiver of the base station 10 in the present disclosure may be configured by at least one of the transmitter / receiver 120, the transmitter / receiver antenna 130, and the transmission path interface 140.

[0253] The transceiver 120 may transmit information about timing advance groups corresponding to multiple transmission / reception points of a specific cell (e.g., SpCell). If timing advance groups corresponding to multiple transmission / reception points can be set separately, the controller 110 may control reception based on the timing advance for each transmission / reception point. Furthermore, the controller 110 may determine a timing advance group to be the primary timing advance group based on at least one of the cell type and transmission / reception point index belonging to each timing advance.

[0254] The transceiver 120 may transmit information about timing advance groups corresponding to multiple transmission / reception points of a specific cell (e.g., SpCell). When multiple transmission / reception points belong to the same timing advance group, the controller 110 may issue a timing advance command corresponding to only one transmission / reception point or multiple transmission points, and control the timing advances of the multiple transmission / reception points, respectively.

[0255] (User Terminal) Fig. 15 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.

[0256] In this example, the functional blocks of the characteristic parts of the present embodiment are mainly shown, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. Some of the processing of each unit described below may be omitted.

[0257] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be configured from a controller, a control circuit, etc., which are described based on common understanding in the technical field to which the present disclosure relates.

[0258] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may control transmission and reception, measurement, etc. using the transceiver unit 220 and the transceiver antenna 230. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as signals and transfer them to the transceiver unit 220.

[0259] The transceiver unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transceiver unit 220 may be configured with a transmitter / receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measurement circuit, a transceiver circuit, etc., which are described based on common understanding in the technical field related to the present disclosure.

[0260] 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.

[0261] The transmitting / receiving antenna 230 can be configured from an antenna described based on common understanding in the technical field to which the present disclosure relates, such as an array antenna.

[0262] 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.

[0263] The transceiver unit 220 may form at least one of the transmit beam and the receive beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0264] The transceiver unit 220 (transmission processing unit 2211) may perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control), etc. on data, control information, etc. obtained from the control unit 210, and generate a bit string to be transmitted.

[0265] The transmitter / receiver unit 220 (transmission processing unit 2211) may perform transmission processing such as channel coding (which may include error correction coding), modulation, mapping, filtering, DFT processing (if necessary), IFFT processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output a baseband signal.

[0266] Whether or not to apply DFT processing may be based on the setting of transform precoding. When transform precoding is enabled for a certain channel (e.g., PUSCH), the transceiver unit 220 (transmission processing unit 2211) may perform DFT processing as the transmission processing to transmit the channel using a DFT-s-OFDM waveform, and if not, it may not be necessary to perform DFT processing as the transmission processing.

[0267] The transceiver unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc. on the baseband signal to a radio frequency band, and transmit the radio frequency band signal via the transceiver antenna 230.

[0268] On the other hand, the transceiver unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc. on the radio frequency band signal received by the transceiver antenna 230.

[0269] The transceiver unit 220 (reception processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal, and acquire user data, etc.

[0270] The transceiver 220 (measurement unit 223) may perform measurements on the received signal. For example, the measurement unit 223 may perform RRM measurements, CSI measurements, etc. based on the received signal. The measurement unit 223 may measure received power (e.g., RSRP), received quality (e.g., RSRQ, SINR, SNR), signal strength (e.g., RSSI), propagation path information (e.g., CSI), etc. The measurement results may be output to the control unit 210.

[0271] The transmitting unit and receiving unit of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting / receiving unit 220 and the transmitting / receiving antenna 230.

[0272] The transceiver 220 may receive information about timing advance groups corresponding to multiple transmission / reception points of a specific cell. If timing advance groups corresponding to multiple transmission / reception points can be set separately, the controller 210 may control the timing advance for each transmission / reception point. Furthermore, the controller 210 may determine a timing advance group to be the primary timing advance group based on at least one of the cell type and transmission / reception point index belonging to each timing advance.

[0273] The controller 210 may determine that a timing advance group including a transmission / reception point of a specific cell is the primary timing advance group. Alternatively, the controller 210 may determine that a timing advance group including a transmission / reception point having a specific index of a specific cell is the primary timing advance group. The controller 210 may also control to change the operation of the timing advance timers after expiration based on the number of timing advance timers that expire simultaneously among multiple timing advance timers corresponding to multiple transmission / reception points, respectively.

[0274] The transceiver unit 220 may receive information about timing advance groups corresponding to multiple transmission and reception points of a specific cell. When multiple transmission and reception points belong to the same timing advance group, the control unit 210 may control the timing advances of the multiple transmission and reception points based on a timing advance command corresponding to only one transmission and reception point or based on timing advance commands corresponding to multiple transmission points.

[0275] The control unit 210 may share and apply one time alignment timer to multiple TRPs. When a timing advance command is issued for each of multiple transmission / reception points, the control unit 210 may control the timing advance timer to change its operation after expiration based on the number of timing advance timers that expire simultaneously among multiple timing advance timers corresponding to the multiple transmission / reception points.

[0276] When a timing advance command is instructed for each of multiple transmission / reception points, one or more sub-timing advance groups are set within the timing advance command, and the same timing advance command and the same timing advance timer may be applied to transmission / reception points included in the same sub-timing advance group.

[0277] (Hardware Configuration) Note that the block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using a single device that is physically or logically coupled, or may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wires, wirelessly, etc.) and these multiple devices. The functional block may be realized by combining software with the single device or the multiple devices.

[0278] Here, the functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs transmission may be called a transmitting unit, transmitter, etc. As described above, the implementation method of each is not particularly limited.

[0279] For example, a base station, a user terminal, etc. according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 16 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. The above-described base station 10 and user terminal 20 may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0280] In the present disclosure, the terms apparatus, circuit, device, section, unit, etc. may be used interchangeably. The hardware configurations of the base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0281] 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.

[0282] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading specified software (programs) onto hardware such as a processor 1001 and a memory 1002, causing the processor 1001 to perform calculations, control communication via the communication device 1004, and control at least one of reading and writing data in the memory 1002 and the storage 1003.

[0283] The processor 1001, for example, runs an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, at least a part of the above-mentioned control unit 110 (210), transceiver unit 120 (220), etc. may be realized by the processor 1001.

[0284] The processor 1001 also reads programs (program codes), software modules, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes in accordance with these. The programs used are those that cause a computer to execute at least some of the operations described in the above-described embodiments. For example, the control unit 110 (210) may be implemented by a control program stored in the memory 1002 and running on the processor 1001, and the other functional blocks may be implemented in a similar manner.

[0285] The memory 1002 is a computer-readable recording medium and may be configured by at least one of, for example, Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EEPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. The memory 1002 may also be referred to as a register, cache, main memory, etc. The memory 1002 may store executable programs (program codes), software modules, etc. for implementing a wireless communication method according to an embodiment of the present disclosure.

[0286] Storage 1003 is a computer-readable recording medium and may be composed of at least one of, for example, a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disc (e.g., a Compact Disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray disc), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, a stick, a key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be referred to as an auxiliary storage device.

[0287] 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.

[0288] The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, a light emitting diode (LED) lamp, etc.) that outputs to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one device (e.g., a touch panel).

[0289] 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.

[0290] Furthermore, the base station 10 and the user terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized using this hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

[0291] (Modifications) Note that terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, a channel, a symbol, and a signal (signal or signaling) may be interchangeable. A signal may also be a message. A reference signal may be abbreviated as RS, and may also be called a pilot, pilot signal, etc. depending on the applicable standard. A component carrier (CC) may also be called a cell, frequency carrier, carrier frequency, etc.

[0292] 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.

[0293] Here, the numerology may be a communication parameter applied to at least one of transmission and reception of a signal or channel, and may indicate at least one of, for example, Subcarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, Transmission Time Interval (TTI), number of symbols per TTI, radio frame structure, specific filtering performed by a transceiver in the frequency domain, and specific windowing performed by a transceiver in the time domain.

[0294] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol) in the time domain. A slot may also be a time unit based on numerology.

[0295] 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.

[0296] 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.

[0297] For example, one subframe may be referred to as a TTI, or multiple consecutive subframes may be referred to as a TTI, or one slot or one minislot may be referred to as a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc. instead of a subframe.

[0298] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. Note that the definition of TTI is not limited to this.

[0299] 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.

[0300] 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.

[0301] 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.

[0302] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and greater than or equal to 1 ms.

[0303] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may be determined based on numerology.

[0304] In addition, an RB may include one or more symbols in the time domain and may have a length of one slot, one minislot, one subframe, or one TTI, each of which may be composed of one or more resource blocks.

[0305] In addition, one or more RBs may be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

[0306] 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.

[0307] A Bandwidth Part (BWP), which may also be referred to as a partial bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a Common Reference Point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0308] The BWP may include a UL BWP (BWP for UL) and a DL BWP (BWP for DL). One or more BWPs may be configured for a UE within one carrier.

[0309] 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."

[0310] 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.

[0311] 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.

[0312] 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.

[0313] 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.

[0314] 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.

[0315] 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.

[0316] The notification of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information in the present disclosure may be performed by physical layer signaling (e.g., Downlink Control Information (DCI) and Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB) and System Information Block (SIB)), Medium Access Control (MAC) signaling), other signals, or a combination thereof.

[0317] Note that the physical layer signaling may be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signal), L1 control information (L1 control signal), etc. Furthermore, the RRC signaling may be referred to as an RRC message, such as an RRC Connection Setup message or an RRC Connection Reconfiguration message. Furthermore, the MAC signaling may be notified using, for example, a MAC Control Element (CE).

[0318] 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).

[0319] 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).

[0320] 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.

[0321] Software, instructions, information, etc. may also be transmitted or received over a transmission medium. For example, if software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave), these wired and / or wireless technologies are included within the definition of transmission media.

[0322] 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).

[0323] 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.

[0324] In the present disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNB (eNodeB)," "gNB (gNodeB)," "access point," "transmission point (TP)," "reception point (RP)," "transmission / reception point (TRP)," "panel," "cell," "sector," "cell group," "carrier," "component carrier," etc. may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, picocell, etc.

[0325] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be partitioned into multiple smaller areas, and each smaller area can be provided with communication service by a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). The terms "cell" or "sector" refer to part or all of the coverage area of ​​a base station and / or base station subsystem that provides communication service within that coverage.

[0326] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0327] 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.

[0328] 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.

[0329] 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.

[0330] 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.

[0331] 17 is a diagram showing an example of a vehicle according to an embodiment. The 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.

[0332] 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 a user.

[0333] The electronic control unit 49 is composed of a microprocessor 61, memory (ROM, RAM) 62, and a communication port (for example, 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).

[0334] 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.

[0335] 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 (e.g., multimedia information / multimedia services) to the occupants of the vehicle 40.

[0336] 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.

[0337] The driving assistance system unit 64 includes various devices for providing functions to prevent accidents and reduce 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.

[0338] 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.

[0339] 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 base station 10 or the user terminal 20 described above. Furthermore, the communication module 60 may be, for example, at least one of the base station 10 and the user terminal 20 described above (or may function as at least one of the base station 10 and the user terminal 20).

[0340] 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.

[0341] The communication module 60 receives various information (traffic information, traffic signal information, vehicle distance information, etc.) transmitted from an external device 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)).

[0342] 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.

[0343] Furthermore, a base station in the present disclosure may be read as a user terminal. For example, the aspects / embodiments of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple user terminals (which may be called, for example, Device-to-Device (D2D) or Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may be configured to have the functions of the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, terms such as an uplink channel and a downlink channel may be read as a sidelink channel.

[0344] 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.

[0345] In the present disclosure, an operation described as being performed by a base station may be performed by its upper node in some cases. It is apparent that in a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (such as, but not limited to, a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc.), or a combination thereof.

[0346] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0347] 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 802.17 (WiMAX (registered trademark)), IEEE 802.19 (WiMAX (registered trademark)), IEEE 802.20 (WiMAX (registered trademark)), IEEE 802.21 (Wi-Fi (registered trademark)), IEEE 802.22 (WiMAX (registered trademark)), IEEE 802.23 (WiMAX (registered trademark)), IEEE 802.24 (WiMAX (registered trademark)), IEEE 802.25 (WiMAX (registered trademark)), IEEE 802.26 (WiMAX (registered trademark)), IEEE 802.27 (WiMAX (registered trademark)), IEEE 802.28 (WiMAX (registered trademark)), IEEE 802.29 (WiMAX (registered trademark)), IEEE 802.30 (WiMAX (registered trademark)), IEEE 802.31 (Wi-Fi (registered trademark)), IEEE 802.32 (WiMAX (registered trademark)), IEEE 802.33 (WiMAX (registered trademark)), IEEE 802. The present invention may be applied to systems that use IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other suitable wireless communication methods, or to next-generation systems that are expanded, modified, created, or defined based on these. Furthermore, the present invention may be applied to a combination of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0348] 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."

[0349] 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.

[0350] 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.

[0351] 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.

[0352] Also, "determination" may be considered to be "deciding" resolving, selecting, choosing, establishing, comparing, etc. In other words, "determination" may be considered to be "deciding" some action.

[0353] Furthermore, "judgment (decision)" may be read as "assuming," "expecting," "considering," or the like.

[0354] 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."

[0355] 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.

[0356] 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."

[0357] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

[0358] 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.

[0359] 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 for receiving information regarding timing advance groups (TAGs) corresponding to a plurality of transmission and reception points of a serving cell; A control unit that controls a timing advance (TA) for each of the plurality of transmission and reception points when TAGs corresponding to the plurality of transmission and reception points are set separately, A terminal in which the control unit changes operation for the one TAG whose time alignment timer has expired when a time alignment timer corresponding to one of the TAGs set for each of the multiple transmitting and receiving points has expired and the time alignment timers corresponding to the remaining TAGs have not expired.

2. The operation to be changed is: Clearing all downlink (DL) assignments associated with the one TAG for which the time alignment timer expired; - clearing all uplink (UL) assignments associated with the one TAG for which the time alignment timer expired; Clearing Physical Uplink Shared Channel (PUSCH) resources for semi-persistent channel state information (CSI) reporting; - Maintain the TA of all TAGs, The terminal according to claim 1 , further comprising:

3. A terminal as described in claim 1, wherein the TAG setting is applied in inter-cell operations.

4. The terminal as described in claim 1, further comprising a transmitting unit that transmits UE capability information regarding whether or not different TAs are supported for the multiple transmission / reception points.

5. A method for receiving information regarding timing advance groups (TAGs) corresponding to a plurality of transmission and reception points of a serving cell; When TAGs corresponding to the plurality of transmission / reception points are set separately, controlling a timing advance (TA) for each of the transmission / reception points; A wireless communication method for a terminal, comprising: when a time alignment timer corresponding to one of the tags set for each of the multiple transmission and reception points has expired and the time alignment timers corresponding to the remaining tags have not expired, changing the operation of the terminal with respect to the one tag whose time alignment timer has expired.

6. A system including a terminal and a base station, The terminal includes: A receiving unit for receiving information regarding a timing advance group (TAG) corresponding to a plurality of transmission and reception points of a serving cell; A control unit that controls a timing advance (TA) for each of the plurality of transmission and reception points when TAGs corresponding to the plurality of transmission and reception points are set separately, the control unit, when a time alignment timer corresponding to one of the tags set in each of the plurality of transmitting and receiving points has expired and the time alignment timers corresponding to the remaining tags have not expired, changes an operation for the one tag whose time alignment timer has expired; The base station, The system includes a transmitter that transmits the information to the terminal.