Terminals, wireless communication methods, base stations and systems

Abstract

A terminal according to one aspect of the present disclosure comprises: a reception unit that receives information relating to a serving cell and a candidate cell; and a control unit that uses, when a plurality of methods for acquiring timing advance corresponding to the candidate cell are supported, a method for acquiring timing advance selected on the basis of at least one of a higher-layer parameter and a predetermined rule to acquire the timing advance corresponding to the candidate cell.

Description

[Technical Field]

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

[0002] In Universal Mobile Telecommunications System (UMTS) networks, Long Term Evolution (LTE) was standardized for the purposes of achieving higher data rates, lower latency, and the like (Non-Patent Document 1). Furthermore, LTE-Advanced (3GPP Rel. 10 to 14) was standardized for the purposes of achieving further increased capacity and higher sophistication beyond LTE (Third Generation Partnership Project (3GPP) Release (Rel.) 8, 9).

[0003] Successor systems to LTE (also referred to as, for example, 5th generation mobile communication system (5G), 5G+ (plus), 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel. 15 and later versions, etc.) are also under study. [Prior Art Documents] [Non-Patent Documents]

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

[0005] Future wireless communication systems (e.g., wireless communication systems beyond Rel.16 / 5G) are expected to control communication based on inter-cell mobility, including non-serving cells, or inter-cell mobility using multiple transmit / receive points (e.g., Multi-TRP (MTRP)). In inter-cell mobility, candidate cells are set up separately from serving cells, and switching between serving cells and candidate cells is also envisioned.

[0006] However, when applying inter-cell mobility (e.g., switching between serving and candidate cells), the question arises as to how to control UL transmission (for example, timing advance control). If inter-cell mobility cannot be properly implemented, the quality of communication may deteriorate.

[0007] This disclosure is made in view of the above, and relates to a terminal and wireless communication method that can appropriately control communication even when performing inter-cell mobility. 、 base station and system One of the objectives is to provide it. [Means for solving the problem]

[0008] A terminal relating to one aspect of this disclosure is A transmitter that reports the ability to support terminal-based timing advance (TA) measurement, Candidate cell A cell switching instruction to switch to is issued by the Medium Access Control Control Element (MAC CE). The receiving unit that receives the signal, The aforementioned MAC CE The candidate cell The TA value is not included. case, The TA measured by the aforementioned terminal-based TA measurement is applied to the uplink (UL) transmission in the candidate cell. It has a control unit that does the following. [Effects of the Invention]

[0009] According to one aspect of this disclosure, communication can be appropriately controlled even when performing inter-cell mobility. [Brief explanation of the drawing]

[0010] [Figure 1] Figures 1A and 1B show an example of inter-cell mobility. [Figure 2] Figure 2 shows an example of switching between a serving cell and an additional cell using L1 / L2 signaling. [Figure 3] Figure 3 shows an example of settings 1-3 when candidate cells are supported. [Figure 4] Figures 4A-4C show an example of how candidate cells / candidate cell groups are switched using L1 / L2 signaling in setting example 1-3 when candidate cells are supported. [Figure 5] Figure 5 shows an example of a Timing Advance Group (TAG) to which cells included in a cell group belong. [Figure 6] Figure 6 shows an example of a MAC CE for timing advance commands. [Figure 7] Figures 7A and 7B show examples of TAG IDs set for serving cells and candidate cells. [Figure 8] Figure 8 shows an example of setting / defining the TA acquisition method for each candidate cell according to the first embodiment. [Figure 9] Figure 9 shows an example of obtaining TA of candidate cells according to the first embodiment. [Figure 10] Figure 10 shows another example of obtaining TA of candidate cells according to the first embodiment. [Figure 11] Figure 11 shows an example of setting / defining a reference cell for each candidate cell according to the second embodiment. [Figure 12] Figure 12 shows an example of calculating the TA based on the reception timing difference between a candidate cell and a reference cell (synchronous) according to the second embodiment. [Figure 13] Figure 13 shows an example of calculating the TA based on the reception timing difference between a candidate cell and a reference cell (asynchronous) according to the second embodiment. [Figure 14] FIG. 14 is a diagram illustrating an example of TA acquisition of a candidate cell according to the third embodiment. [Figure 15] FIG. 15 is a diagram illustrating another example of TA acquisition of a candidate cell according to the third embodiment. [Figure 16] FIG. 16 is a diagram illustrating another example of TA acquisition of a candidate cell according to the third embodiment. [Figure 17] FIG. 17 is a diagram illustrating another example of TA acquisition of a candidate cell according to the third embodiment. [Figure 18] FIG. 18 is a diagram illustrating an example of a schematic configuration of a radio communication system according to an embodiment. [Figure 19] FIG. 19 is a diagram illustrating an example of a configuration of a base station according to an embodiment. [Figure 20] FIG. 20 is a diagram illustrating an example of a configuration of a user terminal according to an embodiment. [Figure 21] FIG. 21 is a diagram illustrating an example of a hardware configuration of a base station and a user terminal according to an embodiment. [Figure 22] FIG. 22 is a diagram illustrating an example of a vehicle according to an embodiment. DESCRIPTION OF EMBODIMENTS

[0011] (TCI, spatial relation, QCL) In NR, it is studied to control at least one of reception processing (for example, at least one of reception, demapping, demodulation, and decoding) and transmission processing (for example, at least one of transmission, mapping, precoding, modulation, and encoding) at a UE for at least one of a signal and a channel (expressed as a signal / channel) based on a Transmission Configuration Indication state (TCI state).

[0012] A TCI state may indicate one that is applied to a downlink signal / channel. A TCI state equivalent that is applied to an uplink signal / channel may be expressed as a spatial relation.

[0013] TCI status refers to information about signal / channel quasi-co-location (QCL), and may also be called spatial reception parameters or spatial relation information. TCI status may be set for each channel or signal in the UE.

[0014] QCL is an index that indicates the statistical properties of a signal / channel. For example, if two signals / channels have a QCL relationship, it may mean that we can assume that at least one of the following is identical between these different signals / channels: Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (e.g., spatial Rx parameter).

[0015] The spatial reception parameters may correspond to the UE's received beam (e.g., the received analog beam), and the beam may be identified based on the spatial QCL. In this disclosure, QCL (or at least one element of QCL) may be interpreted as sQCL (spatial QCL).

[0016] QCL may have multiple types (QCL types). For example, there may be four QCL types A and D that differ in the parameters (or parameter sets) that can be assumed to be the same, and these parameters (which may also be called QCL parameters) are shown below: • QCL Type A (QCL-A): Doppler shift, Doppler spread, mean delay, and delay spread. • QCL Type B (QCL-B): Doppler shift and Doppler spread, • QCL Type C (QCL-C): Doppler shift and mean delay, • QCL Type D (QCL-D): Spatial reception parameters.

[0017] The assumption by the UE that one control resource set (CORESET), channel, or reference signal is in a specific QCL (e.g., QCL type D) relationship with another CORESET, channel, or reference signal may be called a QCL assumption.

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

[0019] The TCI state may, for example, be information regarding the QCL between the target channel (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 upper-layer signaling, physical layer signaling, or a combination thereof.

[0020] In this disclosure, the upper-layer signaling may be, for example, Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, or a combination thereof.

[0021] MAC signaling may use, for example, MAC Control Elements (MAC CEs) or MAC Protocol Data Units (PDUs). Broadcast information may also include, for example, Master Information Blocks (MIBs), System Information Blocks (SIBs), Remaining Minimum System Information (RMSIs), or Other System Information (OSIs).

[0022] Physical layer signaling may include, for example, Downlink Control Information (DCI).

[0023] The channel / signal to which the TCI status applies may also be called the target channel / reference signal (target channel / RS), or simply the target, while the other signal mentioned above may be called the reference signal (reference RS), source RS, or simply the reference.

[0024] The channel on which the TCI state or spatial relationship is set (specified) may be, for example, at least one of the following: Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH), Physical Uplink Shared Channel (PUSCH), or Physical Uplink Control Channel (PUCCH).

[0025] Furthermore, the RS that has a QCL relationship with the channel may be at least one of the following: 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), or a Demodulation Reference Signal (DMRS)).

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

[0027] The RS of a QCL type X in a TCI state may also mean the RS in the relationship between a channel / signal (or its DMRS) and a QCL type X, and this RS may also be called the QCL source of the QCL type X in that TCI state.

[0028] (Inter-cell mobility) In NR, it is being considered that one or more transmission / reception points (TRPs) (multi-TRPs (MTRPs)) will perform DL transmissions to the UE. It is also being considered that the UE will perform UL transmissions to one or more TRPs.

[0029] In inter-cell mobility (e.g., L1 / L2 inter-cell mobility), the UE may receive DL channel / DL signals from multiple cells / TRPs (see Figures 1A and 1B).

[0030] Figure 1A shows an example of inter-cell mobility including non-serving cells (e.g., Single-TRP inter-cell mobility). The UE may configure 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 from the base station / TRP of cell #3, which is not the serving cell (it becomes a non-serving cell). This corresponds, for example, to the UE switching from cell #1 to cell #3 (e.g., a fast cell switch).

[0031] In this case, the selection of a port (e.g., an antenna port) / TRP may be performed dynamically. The selection of a port (e.g., an antenna port) / TRP may be performed based on the TCI status indicated or updated by the DCI / MAC CE. Here, we show a case where different physical cell IDs (e.g., PCI) are supported for cell #1 and cell #3.

[0032] Figure 1B shows an example of a multi-TRP scenario (e.g., multi-TRP inter-cell mobility). The UE may have multiple (e.g., two) TRPs (or different CORESET pool indices) configured in each cell. Here, the UE receives channels / signals from TRP#1 and TRP2. Furthermore, TRP#1 corresponds to physical cell ID (PCI)#1 and TRP#2 corresponds to PCI#2.

[0033] Multiple TRPs (TRP#1, #2) may be connected by an ideal / non-ideal backhaul, and information, data, etc., may be exchanged. Each TRP in a multi-TRP may transmit the same or different codewords (CW) and the same or different layers. As one form of multi-TRP transmission, Non-Coherent Joint Transmission (NCJT) may be used, as shown in Figure 1B. Here, we show the case where NCJT is performed between TRPs corresponding to different PCIs. Note that the same serving cell settings may be applied / configured for TRP#1 and TRP#2.

[0034] Multiple PDSCHs (Multi-PDSCHs) that are NCJTed may be defined as partially or completely overlapping with respect to at least one of the time and frequency domains. That is, a first PDSCH from TRP#1 and a second PDSCH from TRP#2 may overlap in at least one of the time and frequency resources. The first and second PDSCHs may be used for transmitting the same TB or for transmitting different TBs.

[0035] These first and second PDSCHs may be assumed not to be quasi-co-located. Reception of multiple PDSCHs may be reinterpreted as simultaneous reception of PDSCHs that are not of a certain QCL type (e.g., QCL type D).

[0036] Multiple PDSCHs from a multi-TRP (which may also be called multiple PDSCHs) may be scheduled using a single DCI (single DCI (S-DCI), single PDCCH) (single master mode). A single DCI may be transmitted from one TRP in the multi-TRP. A configuration using a single DCI in a multi-TRP may be called a single-DCI-based multi-TRP (mTRP / MTRP).

[0037] Multiple PDSCHs from a multi-TRP may be scheduled using multiple DCIs (multi-DCI (M-DCI), multi-PDCCH (multiple PDCCH)) (multi-master mode). Multiple DCIs may be transmitted from each of the multi-TRPs. A configuration that utilizes multiple DCIs in a multi-TRP may be called a multi-DCI-based multi-TRP (mTRP / MTRP).

[0038] A UE may assume that it sends separate CSI reports (CSI reports) for different TRPs, each for each TRP. Such CSI feedback may be called separate feedback, separate CSI feedback, etc. In this disclosure, “separate” may be interpreted as “independent.”

[0039] In Rel.17 NR, MAC CE / DCI is expected to support beam instruction to TCI states associated with different PCIs. On the other hand, in Rel.18 NR and later, L1 / L2 signaling (e.g., DCI / MAC CE) is expected to support serving cell switching (e.g., instruction to change serving cells to cells with different PCIs) (see Figure 2).

[0040] Figure 2 illustrates a case where the UE switches from the serving cell to an additional cell (also called a candidate cell or target cell) based on a cell switching instruction from the base station.

[0041] (Candidate cell) In inter-cell mobility, it is conceivable that one or more candidate cells may be set up and managed for each serving cell.

[0042] For example, one or more candidate cells may be configured with limited information (e.g., only some parameters are communicated to the UE) in a given upper-layer parameter (e.g., ServingCellConfig) (Alt.1). This may be configured similarly to the inter-cell beam management (inter-cell BM) of existing systems (e.g., Rel.17).

[0043] Alternatively, a complete configuration (e.g., ServingCellConfig) for one or more candidate cells may be configured, and that candidate cell may be associated with each serving cell (Alt. 2). For example, a carrier aggregation configuration framework (e.g., CA configuration framework) or a CHO (Conditional Handover) / CPC (Conditional PSCell Change) configuration framework may be reused.

[0044] In Alt.1 / 2, the activation / deactivation of candidate cells may be controlled by MAC CE / DCI.

[0045] As for the candidate cell settings, at least one of the following setting examples 1 to 3 may be applied (see Figure 3). Here, SpCell#0, SCell#1, and SCell#2 are set as serving cells, and an example of setting / associating candidate cells (or additional cells) with serving cells / cell groups is shown. Setting examples 1 to 3 below are just examples, and the number of cells, the association of each cell, etc., are not limited to these and may be changed as appropriate. Alternatively, other setting examples may be supported / applied in addition to / instead of setting examples 1 to 3.

[0046] Configuration Example 1 shows a case where one or more candidate cells are associated with / configured for each serving cell (see Figure 3). Specifically, it shows a case where candidate cells #0-1, #0-2, and #0-3 are associated with SpCell#0, candidate cell #1-1 is associated with SCell#1, and candidate cells #2-1 and #2-2 are associated with SCell#2. Information regarding these associations may be set / instructed by the base station to the UE via RRC / MAC CE / DCI.

[0047] Configuration Example 2 shows a case where candidate cells are associated with / configured for a MAC entity / MCG / SCG (see Figure 3). Specifically, it shows a case where candidate cells #3-#8 are associated with a MAC entity / MCG / SCG. In this case, candidate cells are configured for the MAC entity or cell group (e.g., MCG / SCG), rather than being associated with each serving cell. Information regarding the candidate cells to be configured for each cell may be configured / instructed by the base station to the UE via RRC / MAC CE / DCI.

[0048] In Configuration Example 3, one or more candidate cell groups may be configured (see Figure 3). Specifically, this shows a case where candidate cell group #1 has candidate cells #0-#2, candidate cell group #2 has candidate cells #0 and #1, and candidate cell group #3 has candidate cell #0. A candidate cell group has one or more candidate cells. Candidate cells included in a candidate cell group may be associated with at least one serving cell. Information about candidate cells may be set / instructed to the UE from the base station via RRC / MAC CE / DCI.

[0049] Existing systems (e.g., Rel.17) support L1 beam indication to TCI states associated with additional PCIs (or additional cells) (e.g., indication via the TCI state field of the DCI).

[0050] Starting with Rel.18, it is expected that new L1 / L2 signals (e.g., DCI / MAC CE) will be supported to instruct serving cell switching (e.g., serving cell switching). It is expected that at least one of implicit and explicit instructions will be supported for such instructions. An implicit instruction may mean, for example, that a CORESET is updated to a TCI state associated with an additional PCI by MAC CE. An explicit instruction may mean that the cell switching is directly instructed by DCI / MAC CE.

[0051] For example, in candidate cell setting example 1, a predetermined candidate cell may be designated as a serving cell (or an instruction to switch to a serving cell) via L1 / L2 signaling (e.g., cell switching instruction / cell switching command). Figure 4A shows a case where candidate cells #0-2 become MCG / SCG SpCells via L1 / L2 signaling (SpCell #0 and candidate cells #0-2 are switched). It also shows a case where candidate cell #2-1 becomes MCG / SCG SCell (SCell #2 and candidate cell #2-1 are switched) via L1 / L2 signaling.

[0052] Alternatively, in candidate cell setting example 2, a predetermined candidate cell may be designated as a serving cell (or instructed to switch to a serving cell) via L1 / L2 signaling. Figure 4B shows a case where candidate cell #4 becomes an MCG / SCG SpCell via L1 / L2 signaling (SpCell #0 and candidate cell #4 are switched).

[0053] Alternatively, in candidate cell setting example 3, a predetermined candidate cell group (or one or more candidate cells included in the predetermined candidate cell group) may be changed / updated to a serving cell group via L1 / L2 signaling. Figure 4C shows a case where candidate cell group #1 (or candidate cells #0-#2 included in candidate cell group #1) becomes a serving cell group (the serving cell group and candidate cell group #1 are switched) via L1 / L2 signaling.

[0054] (Timing Advance Group) When using multiple TRPs, the distance between the UE and each TRP may differ. Multiple TRPs may be contained within the same cell (e.g., a serving cell). Alternatively, some TRPs may correspond to a serving cell, while others correspond to non-serving cells. In this case, it is conceivable that the distance between each TRP and the UE will differ.

[0055] In existing systems, the transmission timing of UL (Uplink) channels and / or UL signals (UL channels / signals) is adjusted by Timing Advance (TA). The reception timing of UL channels / signals from different user terminals (UEs) is adjusted at the base station (TRP: Transmission and Reception Point, also known as gNB: gNodeB, etc.).

[0056] The UE may control the timing of UL transmission by applying a timing advance (multiple timing advance) for each pre-configured timing advance group (TAG).

[0057] When applying multiple timing advances, Timing Advance Groups (TAGs) are supported, categorized by transmission timing. 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.

[0058] When applying Multiple Timing Advance, the UE can independently adjust the transmission timing of the cells belonging to each TAG, allowing the radio base station to synchronize the uplink signal reception timing from the UE, even when using multiple cells.

[0059] TAGs (for example, serving cells belonging to the same TAG) may be set by higher-level layer parameters. The same timing advance value may be applied to serving cells belonging to the same TAG (for example, serving cells to which UL is set). A timing advance group containing a MAC entity's SpCell may be called a primary timing advance group (PTAG), and other TAGs may be called secondary timing advance groups (STAG). The maximum number of TAGs may also be X (for example, X=4) per cell group (for example, MCG / SCG).

[0060] In existing systems (e.g., Rel.16 NR), the setting of up to four TAGs is supported per cell group (e.g., MCG / SCG) (see Figure 5). Figure 5 shows a case where three TAGs are set for a cell group containing SpCell and SCell#1~#4. Here, 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 belong to the third TAG (TAG#2).

[0061] A timing advance command (TA command) may be communicated to the UE using a MAC control element (e.g., MAC CE). The TA command is a command indicating the transmission timing value for the uplink channel and is included in the MAC control element. The TA command is signaled to the UE from the radio base station at the MAC layer. The UE controls a predetermined timer (e.g., a TA timer) based on the reception of the TA command.

[0062] A MAC CE for timing advance commands may include a field for a timing advance group index (e.g., TAG ID) and a field for the timing advance command (see Figure 6). The TAG ID field is used to indicate the TAG ID of an addressed TAG. The timing advance command field is an index value T used to control the amount of timing adjustment that the MAC entity must apply. A (0, 1, 2...63) may also be shown.

[0063] The parameters corresponding to each TAG ID may be set by higher-layer parameters. For example, a parameter such as a time alignment timer (e.g., timeAlignmentTimer) may be set for each TAG ID. Alternatively, the TAG ID for each serving cell may be set by higher-layer parameters (e.g., tag-ID included in ServingCellConfig). Note that the TAG ID / parameter may be updated by MAC CE after being set by higher-layer parameters.

[0064] Time alignment timers may be maintained for UL time alignment. In Rel.17, time alignment timers may be set / associated per TAG. When the UE receives a MAC CE for a timing advance command (e.g., TAC MAC CE), it starts or restarts the time alignment timers associated with the indicated timing advance group (e.g., TAG).

[0065] The MAC entity receives the TAC MAC CE and a predetermined value (N) between it and the indicated TAG. TA If the specified value (N) is maintained, apply the timing advance command to the specified TAG, or start or restart the time alignment timer associated with the specified TAG. TA ) may also be a timing advance between DL and UL.

[0066] The behavior when the time alignment timer expires may be defined separately for PTAG and STAG. Furthermore, the timing advance group (TAG) containing the MAC entity's SpCell may be called the primary timing advance group (PTAG), and the other TAGs may be called secondary timing advance groups (STAG).

[0067] For example, in Rel.17, it is supported that when the timing advance timer corresponding to PTAG expires, a predetermined operation for PTAG is applied, and when the timing advance timer corresponding to STAG expires, a predetermined operation for STAG is applied.

[0068] For example, if the time alignment timer expires, the following actions (e.g., a predetermined PTAG action / a predetermined STAG action) may be performed.

[0069] [Operation for specified PTAGs] If the time alignment timer is associated with the PTAG, • Flushes all HARQ buffers in all serving cells. • If configured, notify RRC to release PUCCH for all serving cells. • If configured, notify RRC to release the SRS. • Clear all configured DL (Download) and UL (Ultimate Load) allocations. Clear the PUSCH resources for semi-persistent CSI reporting. • Complete all time alignment timers during your run. • All TAGs N TA Maintain.

[0070] [Operation for specified STAG] If a time alignment timer is associated with a STAG, then for all serving cells belonging to that TAG, • Flushes all HARQ buffers. • If configured, notify RRC to release PUCCH. • If configured, notify RRC to release the SRS. • Clear all configured DL and UL assignments. Clear the PUSCH resources for semi-persistent CSI reporting. • N of the TAG TA Maintain.

[0071] When candidate cells are set / defined, it may be supported to control communication considering the corresponding timing advance (TA) for each candidate cell. For example, as described above, each candidate cell may be associated with a TAG (see Figures 7A and 7B). Figure 7A shows an example of TAG (or TAG ID setting) per cell group in an existing system (e.g., Rel. 17 or earlier), and Figure 7B shows an example of setting a TAG ID for each candidate cell.

[0072] Furthermore, once a candidate cell is configured / applied / supported, it is expected that different serving cells / different candidate cells will be associated with the same TAG, as shown in Figure 7B. The candidate cell's TAG may be instructed by the base station or determined by the UE based on the candidate cell's TAG obtained.

[0073] It is also conceivable that the UE might consider the TA (Time Agent) corresponding to a candidate cell when sending a UL (Urgent Request) for a candidate cell (for example, a candidate cell that has been instructed to switch to a serving cell). If the TA of a candidate cell is considered, the UE will need to acquire the TA of the candidate cell (for example, TA acquisition of candidate cells).

[0074] Several methods for obtaining TA (Technical Analysis) of candidate cells are possible, including TA acquisition using RACH (e.g., RACH-based solutions) and TA acquisition without using RACH (RACH-less solutions). The TA acquisition method may also be interpreted as a TA acquisition scheme, TA acquisition type, or TA acquisition procedure. In this disclosure, TA acquisition, TA measurement, TA calculation, TA determination, and TA determination may be interpreted interchangeably.

[0075] For example, a UE may obtain the TA of a candidate cell by sending a RACH (e.g., PDCCH order RACH) instructed / triggered by a PDCCH to the candidate cell. Information about the candidate cell's TA (e.g., TA value) may be included in the RACH response signal (e.g., RAR). The RAR may be sent from the serving cell or from the candidate cell. Alternatively, the candidate cell's TA may be obtained using a RACH triggered by the UE or a RACH triggered at a higher layer in the network. The PDCCH order may be triggered by the source cell (or serving cell) alone.

[0076] Alternatively, the UE may obtain the candidate cell's TA by transmitting a signal other than RACH to the candidate cell. Information regarding the candidate cell's TA (e.g., TA value) may be provided to the UE by the base station. As a signal other than RACH, for example, SRS may be applied.

[0077] Alternatively, the UE may measure / calculate / acquire the TA for a candidate cell based on the DL signal (e.g., downlink reference signal) transmitted from each cell (e.g., candidate cell / serving cell). The method by which the UE acquires the TA for a candidate cell based on DL signals transmitted from one or more cells may be called UE-based TA measurement.

[0078] In UE-based TA measurement, the downlink reference signal may be a predetermined DL signal (e.g., a synchronization signal block (e.g., SSB) / CSI-RS, etc.). For example, the UE may measure the difference in reception timing of DL signals from multiple cells (or two cells) and obtain the TA of a candidate cell.

[0079] Multiple cells may include a reference cell (e.g., a serving cell). In this case, the UE may calculate the required TA for the candidate cell based on the reception timing of the reference cell (and the TA value of the reference cell) and the timing difference (e.g., T) between the reference cell and the candidate cell. The UE may also obtain the TA of the candidate cell using a timing advance command (TAC) sent from the serving cell.

[0080] Thus, it is assumed that candidate cells are set / applied / supported and the UE obtains the TA of the candidate cells, but the problem is how to obtain the TA of the candidate cells in such a case.

[0081] For example, if multiple methods are supported for obtaining the TA of a candidate cell, the question arises as to which method to apply.

[0082] Alternatively, if a cell (e.g., a candidate cell) that has been configured / decided to perform UE-based TA measurement is asynchronous (or is part of an asynchronous network), the question arises as to how to control the acquisition of the TA for that cell.

[0083] Alternatively, if a switch command is sent to a terminal instructing a switch to a cell (e.g., a candidate cell) that has been configured / decided to perform UE-based TA measurement, the question arises as to how to control the application / acquisition / instruction of the TA value after the switch. For example, if the switch command contains information about the TA, the question arises as to whether to apply the TA obtained by UE-based TA measurement after the switch or the TA instructed by the switch command.

[0084] Alternatively, the question arises as to how to control the application of TA values ​​obtained based on UE-based TA measurement (e.g., TA values ​​for candidate cells). For example, should they be applied to the first UL transmission after a cell switch instruction / command, or to multiple UL transmissions after a cell switch?

[0085] Thus, even when candidate cells are configured / applied / supported, and the UE is supported in acquiring the candidate cell's TA, the method for controlling the acquisition of the candidate cell's TA has not been adequately considered. If the acquisition of the candidate cell's TA is not performed properly, the timing of UL transmission may not be properly controlled, potentially leading to a deterioration in communication quality.

[0086] Therefore, the inventors focused on the fact that TA acquisition of candidate cells (or additional cells, target cells) is supported, and investigated a control method when TA acquisition of said candidate cells is supported, and conceived this embodiment.

[0087] The embodiments relating to this disclosure will be described in detail below with reference to the drawings. Each of the following embodiments (for example, each case) may be used individually or at least two may be applied in combination.

[0088] In this disclosure, "A / B" and "at least one of A and B" may be interpreted as mutually exclusive. In this disclosure, "A / B / C" may mean "at least one of A, B, and C".

[0089] In this disclosure, terms such as activate, deactivate, indicate, select, configure, update, and determine may be interpreted interchangeably. In this disclosure, terms such as support, control, controllable, operate, and operable may be interpreted interchangeably.

[0090] In this disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher-layer parameters, information elements (IE), settings, etc., may be interpreted interchangeably. In this disclosure, Medium Access Control elements (MAC Control Element (CE)), update commands, activation / deactivation commands, etc., may be interpreted interchangeably.

[0091] In this disclosure, the upper-layer signaling may be any or a combination thereof, such as Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, and other messages (e.g., messages from the core network, such as positioning protocol messages (e.g., NR Positioning Protocol A (NRPPa) / LTE Positioning Protocol (LPP)) messages).

[0092] In this disclosure, MAC signaling may include, for example, MAC Control Elements (MAC CEs) and MAC Protocol Data Units (PDUs). Broadcast information may include, for example, Master Information Blocks (MIBs), System Information Blocks (SIBs), Remaining Minimum System Information (RMSIs), and Other System Information (OSIs).

[0093] In this disclosure, physical layer signaling may include, for example, Downlink Control Information (DCI) and Uplink Control Information (UCI).

[0094] In the following embodiments, "multiple" and "two" may be interpreted interchangeably. Also, "TAG" and "TAG ID" may be interpreted interchangeably. Furthermore, "cell," "CC," and "carrier" may be interpreted interchangeably. In the following embodiments, "calculate," "calculate," and "get" may be interpreted interchangeably.

[0095] The following description may apply to inter-cell mobility (e.g., L1 / L2 inter-cell mobility) or to communication control other than inter-cell mobility. L1 / L2 inter-cell mobility may be interpreted as at least one of cell switching, cell change, and cell modification.

[0096] (Wireless communication method) <First Embodiment> In the first embodiment, an example of TA acquisition is described when multiple methods for timing advance acquisition (e.g., TA acquisition) of candidate cells are supported.

[0097] In this disclosure, TA acquisition (or TA to be acquired) may mean initial TA (or the first TA to be acquired) or other TA acquisitions. The method of TA acquisition may include at least two of the following, for example, a first method using RACH, a second method using UE-based TA measurement, and a third other method.

[0098] The UE may receive information about the serving cell and information about candidate cells. The information about the serving cell and information about candidate cells may be set / instructed to the UE by the base station via RRC / MAC CE / DCI. The information about the serving cell may include information such as the cell ID to be set as the serving cell. The information about candidate cells may include information such as the cell ID of the candidate cell (e.g., a cell that is a candidate to switch to a serving cell). In this disclosure, a serving cell may be read as a serving cell group, a source cell, or a source cell group.

[0099] Furthermore, the information regarding serving cells / candidate cells may include information regarding the association between serving cells and candidate cells. For example, a candidate cell associated with a given serving cell may be indicated to the UE. Alternatively, the UE may determine the association between serving cells and candidate cells based on the frequency corresponding to the serving cell and the frequency corresponding to the candidate cell.

[0100] The following explanation uses the example of a case where SpCell#0, SCell#1, and SCell#2 are set as serving cells, and candidate cells #1-#6 are set as candidate cells (see Figure 8). However, the setting of serving cells / candidate cells is just one example and is not limited to this.

[0101] [Option 1-1] The TA acquisition method for candidate cells may be set from the base station to the terminal using upper-layer parameters. For example, the TA acquisition method for candidate cells may be set separately for each candidate cell. Alternatively, the TA acquisition method for candidate cells may be set separately for multiple candidate cells (or candidate cell groups / sets of candidate cells). For example, in the case shown in Figure 8, the TA acquisition method may be set separately for each candidate cell #1-#6. Alternatively, a common TA acquisition method may be set for candidate cells #1-#6. Alternatively, the TA acquisition method may be set for some of the candidate cells among candidate cells #1-#6 (for example, candidate cells #1-#3 / candidate cell #4 / candidate cells #5-#6).

[0102] Alternatively, the TA acquisition method for candidate cells may be set separately for each frequency (or frequency range / CC / band). Alternatively, the TA acquisition method for candidate cells may be set separately for each timing advance group (e.g., TAG). Alternatively, the TA acquisition method for candidate cells may be set commonly based on the corresponding serving cell. For example, a common TA acquisition method may be set for one or more candidate cells corresponding to a certain serving cell.

[0103] If UE-based TA measurement is set as the method for obtaining TA for a candidate cell, the UE may perform TA acquisition using at least one of the following options 1-1-1 to 1-1-2.

[0104] 《Option 1-1-1》 The UE may receive / measure DL signals transmitted from at least one cell containing at least one candidate cell, then calculate the TA of the candidate cell, and apply the obtained TA to UL transmission (see Figure 9).

[0105] For example, a UE may calculate the TA of a cell (e.g., a candidate cell) by receiving / measuring DL signals transmitted from at least one cell containing the candidate cell, prior to receiving a cell switch instruction (e.g., a cell switch command). The UE may then apply the calculated TA to a UL transmission (e.g., a UL transmission to a candidate cell instructed to switch to a serving cell by a cell switch command) after receiving a cell switch command for the candidate cell. In this disclosure, a cell switch command may be interpreted as a cell switch instruction. Cell switch instructions / cell switch commands may be transmitted by at least one of DCI and MAC CE.

[0106] This enables UL transmission based on the appropriate TA to cells that have been instructed to switch from candidate cells to serving cells via a cell switching command (or cell switching instruction). Furthermore, by obtaining the candidate cell's TA before receiving the cell switching command, the UE can immediately apply the obtained TA to the UL transmission of that candidate cell after the cell switching.

[0107] 《Option 1-1-2》 After receiving a cell switching command for a candidate cell, the UE may calculate the TA of the candidate cell by receiving / measuring DL signals transmitted from at least one cell that includes the candidate cell to be switched (see Figure 10).

[0108] In this way, by measuring / calculating the TA of candidate cells to be switched to serving cells after receiving a cell switching command, the number of cells for which the UE measures / calculates the TA can be reduced. This suppresses the increase in the load on the UE associated with TA measurement / calculation.

[0109] In addition, in options 1-1-1 / 1-1-2, candidate cells for which TA acquisition should be performed before receiving the cell switching command, or candidate cells for which TA acquisition should be performed after receiving the cell switching command, may be set in the UE. This allows for flexible control over the timing of TA acquisition for each candidate cell.

[0110] [Options 1-2] The UE may determine how to obtain the TA of a candidate cell based on one or more predetermined conditions / rules. For example, the UE may apply a specific TA acquisition method (e.g., UE-based TA measurement) to a candidate cell if it satisfies predetermined conditions / rules.

[0111] For obtaining TA for a given candidate cell, at least one of the following options 1-2-1 to 1-2-2 may be applied.

[0112] 《Option 1-2-1》 A specific TA acquisition method (e.g., UE-based TA measurement) may be applied to some candidate cells (or specific candidate cells). By default, UE may apply UE-based TA measurement to some candidate cells (or specific candidate cells). Note that UE-based TA measurement may be replaced with other TA acquisition methods.

[0113] Some candidate cells (or specific candidate cells) may be candidate cells with specific parameters / conditions / applications configured. For example, some candidate cells (or specific candidate cells) may be candidate cells configured for L1 beam measurement / reporting, and at least one candidate cell having the same frequency as the current serving cell (e.g., SpCell).

[0114] 《Option 1-2-2》 If a cell switch command does not include information about the TA (Time Object), a specific TA acquisition method (e.g., UE-based TA measurement) may be applied to the target candidate cell. Information about the TA may be interpreted as a TA value or a TA value field (e.g., TA value field). For example, if a UE receives a cell switch command for a candidate cell, it may apply UE-based TA measurement to the target candidate cell to which the switch is to be performed.

[0115] The UE may report UE capability information regarding whether or not it supports UE-based TA measurement. Alternatively, the UE may report capability information regarding the maximum number of cells / TAGs on which it can perform TA measurement / calculations for each frequency / MCG / SCG / UE.

[0116] [Variations] Multiple TA acquisition methods may be configured by the RRC. If a TA is indicated / reported, the TA acquisition method associated with the TA may be applied. For example, if multiple TA acquisition methods are configured / supported and PRACH is triggered by a PDCCH order, TA acquisition of candidate cells may be performed based on the PDCCH order. Alternatively, if multiple TA acquisition methods are configured / supported and the UE reports TA values ​​based on UE-based TA measurement, TA acquisition of candidate cells may be performed based on UE-based TA measurement. In this case, UE reporting of TAs for UE-based TA measurement (e.g., explicit reporting) may be required.

[0117] <Second Embodiment> In the second embodiment, an example of measuring the timing difference / TA calculation of DL signals transmitted from multiple cells, including candidate cells, is described.

[0118] The second embodiment may be suitably applied when UE-based TA measurement is applied as the TA acquisition method. Of course, it is not limited to this. The second embodiment may be applied in appropriate combination with the contents described in the first embodiment (for example, in part or in whole).

[0119] When measuring the DL reception timing difference (e.g., DL RX timing difference) between a candidate cell and other cells, a reference cell may be set / defined. The reference cell may be interpreted as a reference cell, specific cell, or reference cell. The reference cell may be, for example, a specific cell or a cell from which a TA value is indicated / acquired. The reference cell may be defined in the specification or set / instructed by the base station to the UE via RRC / MAC CE / DCI. For example, the reference cell may be determined based on at least one of the following options 2-1 to 2-3.

[0120] [Option 2-1] A specific serving cell (e.g., SpCell) among the current serving cells may be applied as a reference cell. In this case, the specific serving cell (e.g., SpCell) may be used as a reference cell for measuring the timing difference of multiple candidate cells (e.g., all candidate cells in the MCG / SCG).

[0121] For example, in a case where SpCell#0, SCell#1, and SCell#2 are set as serving cells and candidate cells #1-#6 are set as candidate cells (see Figure 11), SpCell#0 may be defined / set as the reference cell. In this case, the timing difference between SpCell#0 and candidate cells #1-#6 may be measured using SpCell#0 as the reference cell, and the timing interaction (TA) of each candidate cell #1-#6 may be obtained. Note that the serving cell / candidate cell settings shown in Figure 11 are just an example and are not limited to this.

[0122] Note that a specific serving cell is not limited to SpCells, but may be other serving cells (for example, SCells).

[0123] [Option 2-2] Reference cells may be set / defined for candidate cells for each unit. For example, reference cells may be set / defined for candidate cells for each frequency (or CC, band, frequency range). As an example, each serving cell for each frequency may be set / defined as a reference cell.

[0124] For example, in a case where SpCell#0, SCell#1, and SCell#2 are set as serving cells and candidate cells #1-#6 are set as candidate cells (see Figure 11), the reference cell for candidate cells #1-#3 may be set to SpCell#0, the reference cell for candidate cell #4 may be set to SCell#1, and the reference cell for candidate cells #5-#6 may be set to SCell#2.

[0125] [Options 2-3] The reference cell may be set / defined separately for each candidate cell. Alternatively, the reference cell may be set / defined in common for multiple candidate cells (e.g., all candidate cells, some candidate cells, a set of candidate cells, or a group of candidate cells).

[0126] For example, in a case where SpCell#0, SCell#1, and SCell#2 are set as serving cells and candidate cells #1-#6 are set as candidate cells (see Figure 11), a separate reference cell corresponding to each of candidate cells #1-#6 may be set.

[0127] The reference cell may be selected from among the candidate cells (for example, candidate cells from which TA has been obtained).

[0128] [TA calculation based on DL reception timing difference] The UE may calculate the TA of a candidate cell by considering the reception timing difference (e.g., delta) of the DL signals transmitted from the candidate cell and other cells (e.g., the reference cell). For example, the UE may calculate the candidate cell's TA (e.g., TA_ca) by considering the timing difference (delta) measured in DL reception with the reference cell's TA (e.g., TA_ref). As an example, the candidate cell's TA (e.g., TA_ca) may be obtained as TA_ca = TA_ref + 2 × delta.

[0129] Different parameters may be applied to the TA calculation when the reference cell and candidate cell are synchronized (Figure 12) and when the reference cell and candidate cell are asynchronized (Figure 13). For example, a predetermined parameter (or predetermined offset) may be considered only when the reference cell and candidate cell are asynchronized. The predetermined parameter (or predetermined offset) may be, for example, an offset that takes into account the difference in reception timing due to asynchronous operation.

[0130] A predetermined offset (or timing offset) for DL ​​reception between each candidate cell and the reference cell may be set separately for each candidate cell. In the case of asynchronous cells, the predetermined offset is set to a value other than 0, and in the case of synchronous cells, the predetermined offset may be set to 0 or no predetermined offset may be specified / set.

[0131] The UE may determine the TA of a candidate cell based on the TA of a reference cell, taking into account both a predetermined offset and the measured DL reception timing difference. For example, for asynchronous cells (e.g., when the candidate cell and the reference cell are asynchronous), the UE may calculate the TA of the candidate cell (e.g., TA_ca) by taking into account a predetermined offset, the TA of the reference cell (e.g., TA_ref), and the timing difference (delta) measured by DL reception. As an example, the TA of a candidate cell (e.g., TA_ca) may be obtained as TA_ca = TA_ref - 2 × predetermined offset + 2 × delta (or TA_ca = TA_ref - predetermined offset + 2 × delta).

[0132] UE capability information regarding whether it supports UE-based TA measurement for synchronous / asynchronous interactions between cells may be defined. Additionally, UE capability regarding the number of synchronous / asynchronous cells performing UE-based TA measurement may be defined.

[0133] [Base cell after cell switching command] In TA acquisition, if the reference cell is a serving cell or SpCell, and the serving cell or SpCell is switched / changed by a cell switching command, the reference cell after the cell switch may be determined based on at least one of the following Alt.2-1 to Alt.2-3.

[0134] 《Alt.2-1》 When a cell switching command is received and the current serving cell (e.g., SpCell) is changed, the reference cell does not need to be changed. In this case, the UE may always calculate the TA of candidate cells based on the reference cell set in RRC.

[0135] 《Alt.2-2》 When a cell switch command is received and the current serving cell (e.g., SpCell) is changed, the reference cell may also be changed to the new serving cell (e.g., a new SpCell). In other words, the reference cell may also be changed in accordance with the cell switch. In this case, the UE may recalculate the timing difference / predetermined offset between the candidate cell and the new (or changed) reference cell and apply the new timing difference / predetermined offset to the TA derivation.

[0136] 《Alt.2-3》 When a cell switching command is received and the current serving cell (e.g., SpCell) is changed, the reference cell may be updated by the RRC / MAC CE. In this case, the DL timing difference / predetermined offset between the candidate cell and the new (or changed) reference cell may be updated by the RRC / MAC CE.

[0137] <Third Embodiment> In the third embodiment, an example of UE operation when a cell switching command (for example, a cell switch command) instructs switching to a candidate cell will be described.

[0138] The third embodiment will be described using, but is not limited to, a case where UE-based TA measurement is set as a method for obtaining TA of a candidate cell. It may also be applied to the PRACH of the PDCCH order for a candidate cell for which UE-based TA measurement has been set. The third embodiment may be applied in appropriate combination with the contents (e.g., some or all) described in the first / second embodiment.

[0139] If a cell switch command is sent to a candidate cell that has been configured / determined to perform UE-based TA measurement, the UE may apply at least one of the following options 3-1 to 3-2. The cell switch command may also be sent via MAC CE (e.g., cell switch command MAC CE).

[0140] [Option 3-1] Configurations in which the cell switching command MAC CE does not include information about TA (e.g., TA value) may be supported.

[0141] For example, a UE may expect / assume that the MAC CE cell switching command for a candidate cell does not include a TA value. If the UE has a TA corresponding to the candidate cell (e.g., has calculated / obtained a TA), it may control the transmission of a UL to the candidate cell (e.g., the candidate cell that has been switched to the serving cell) based on that TA (see Figure 14).

[0142] For example, if a UE obtains a TA for a candidate cell through UE-based TA measurement, and receives a cell switching command MAC CE (e.g., a MAC CE that does not include a TA value) for that candidate cell, it may apply the TA obtained by UE-based TA measurement to the UL transmission to the candidate cell after the cell switching.

[0143] Alternatively, if the UE has not obtained the TA for a candidate cell using UE-based TA measurement, and receives a cell switching command MAC CE (e.g., a MAC CE that does not include a TA value) for that candidate cell, it may apply UE-based TA measurement to calculate / obtain the TA corresponding to that candidate cell, and then apply it to the UL transmission to the candidate cell (see Figure 15).

[0144] In MAC CE, there may be separate fields indicating whether a field (for example, the TA value field) exists. For several other fields in the MAC CE cell switching command, there may be separate fields indicating whether each field exists.

[0145] Some of the other fields may include at least one of the following fields: • Fields that instruct the activation / deactivation of serving cells / candidate cells • A field that instructs the activation of the TCI state of the target serving cell / target candidate cell. • Fields indicating the triggered non-periodic CSI-RS resource instruction / CSI-RS resource set ID / CSI reporting setting ID • Field indicating the triggered non-periodic SRS resource set ID

[0146] [Option 3-2] The cell switching command MAC CE may include information about TA (e.g., TA value). In this case, UE may apply at least one of the following options 3-2-1 to 3-2-3.

[0147] 《Option 3-2-1》 The UE may ignore (or not consider) the TA value specified in the cell switching command. In this case, the UE may apply the TA value obtained by UE-based TA measurement (see Figure 16).

[0148] 《Option 3-2-2》 The UE may apply the TA value specified in the cell switching command. If the UE has a TA value calculated / obtained by UE-based TA measurement, it does not have to apply that calculated / obtained TA value.

[0149] Alternatively, the UE may apply the TA value specified in the cell switch command for a predetermined period after receiving the cell switch command. In other words, the UE may not apply the TA value obtained by UE-based TA measurement for a predetermined period after receiving the cell switch command, but may apply the TA value obtained during a period other than the predetermined period. The UE may apply the TA value calculated / obtained by UE-based TA measurement during a period other than the predetermined period. The predetermined period may be defined in the specification, set / instructed to the UE by RRC / MAC CE / DCI, or reported in the UE capability information.

[0150] Alternatively, if the UE has not obtained the TA for a candidate cell through UE-based TA measurement, and receives a cell switching command MAC CE (for example, a MAC CE that does not contain a TA value) for that candidate cell, it may apply the TA value indicated in the cell switching command. In this case, the UE may be controlled not to perform UE-based TA measurement (see Figure 17). In this way, by making UE-based TA measurement unnecessary when the cell switching command MAC CE contains information about the TA, the increase in the load on the UE can be suppressed.

[0151] 《Option 3-2-3》 If a TA value is specified by a cell switching command and a TA value is obtained by UE-based TA measurement, the UE may autonomously decide which TA value to select or combine the two TA values ​​(UE implementation).

[0152] Furthermore, the third embodiment may be applied to PRACH in the PDCCH order as a method for acquiring the TA of a candidate cell. In this case, the cell switching command (or the cell switching command MAC CE) may be interpreted as PRACH in the PDCCH order (or the TA command, the RAR response signal of PRACH).

[0153] <Fourth Embodiment> In the fourth embodiment, an example of how to apply TA values ​​obtained by UE-based TA measurement will be described.

[0154] The TA values ​​obtained by UE-based TA measurement may be applied according to at least one of the following options 4-1 to 4-2.

[0155] [Option 4-1] The TA value obtained by UE-based TA measurement may be used / executed once during the initial TA acquisition (e.g., initial TA acquisition) or when TA reacquisition occurs due to UL asynchronous operation (e.g., UL asyn.). Thereafter, TA updates may be initiated from the network via TAC.

[0156] The initial acquisition of a Time Alignment (TA) may occur, for example, when the first UL (Ultrasound) is sent after a cell switching command. An asynchronous UL may occur when the time alignment timer (e.g., a time alignment timer) expires.

[0157] [Option 4-2] The TA value obtained by UE-based TA measurement may be used / executed for subsequent UL transmissions (e.g., follow-up UL TX) if instructed by the network via MAC CE / DCI.

[0158] <Supplement> [Notification of information to UE] In the embodiments described above, notification of any information from a Network (NW) (e.g., a Base Station (BS)) to a UE (in other words, reception of any information from a BS at the UE) may be performed using physical layer signaling (e.g., DCI), higher layer signaling (e.g., RRC signaling, MAC CE), specific signals / channels (e.g., PDCCH, PDSCH, reference signal), or a combination thereof.

[0159] If the above notification is made by a MAC CE, the MAC CE may be identified by the inclusion of a new Logical Channel ID (LCID) not defined in existing standards in the MAC subheader.

[0160] If the above notification is made by a DCI, the notification may be made by a specific field of the DCI, a Radio Network Temporary Identifier (RNTI) used to scramble the Cyclic Redundancy Check (CRC) bits assigned to the DCI, or the format of the DCI.

[0161] Furthermore, the notification of any information to the UE in the above-described embodiment may be periodic, semi-persistent, or aperiodic.

[0162] [Notification of information from UE] In the embodiments described above, notification of any information from the UE (to the NW) (in other words, transmission / reporting of any information from the UE to the BS) may be performed using physical layer signaling (e.g., UCI), higher layer signaling (e.g., RRC signaling, MAC CE), specific signals / channels (e.g., PUCCH, PUSCH, PRACH, reference signals), or a combination thereof.

[0163] If the above notification is made by a MAC CE, the MAC CE may be identified by the inclusion of a new LCID, not specified in existing standards, in the MAC subheader.

[0164] If the above notice is issued by the UCI, the notice may be sent using PUCCH or PUSCH.

[0165] Furthermore, the notification of any information from the UE in the above-described embodiments may be periodic, semi-persistent, or aperiodic.

[0166] [Regarding the application of each embodiment] At least one of the embodiments described above may be applied if certain conditions are met. These conditions may be specified in a standard or notified to the UE / BS using upper-layer signaling / physical layer signaling.

[0167] At least one of the embodiments described above may apply only to a UE that has reported or supports a particular UE capability.

[0168] The specific UE capability may represent at least one of the following: • To support UE-based TA measurement, • Maximum number of cells / TAGs that can be measured / calculated for each frequency / MCG / SCG / UE. • Support UE-based TA measurement for synchronous / asynchronous cells. • The maximum number of synchronous / asynchronous cells to which UE-based TA measurement can be applied.

[0169] Furthermore, the above-mentioned specific UE capabilities may be capabilities that apply across all frequencies (commonly regardless of frequency), capabilities per frequency (e.g., one or a combination thereof, such as cell, band, band combination, BWP, component carrier, etc.), capabilities per frequency range (e.g., Frequency Range 1 (FR1), FR2, FR3, FR4, FR5, FR2-1, FR2-2), capabilities per subcarrier spacing (SCS), or capabilities per feature set (FS) or feature set per component-carrier (FSPC).

[0170] Furthermore, the specific UE capabilities described above may be capabilities that apply across all duplexing schemes (common to all duplexing schemes), or they may be capabilities specific to each duplexing scheme (e.g., Time Division Duplex (TDD), Frequency Division Duplex (FDD)).

[0171] Furthermore, at least one of the embodiments described above may be applied when the UE is configured / activated / triggered by upper layer signaling / physical layer signaling to perform certain information (or the actions of the embodiments described above) related to the embodiments described above. For example, such certain information may be information indicating the activation of UE-based TA measurement, or arbitrary RRC parameters for a particular release (e.g., Rel. 18 / 19).

[0172] If the UE does not support at least one of the above-mentioned specific UE capabilities or does not have the above-mentioned specific information configured, the behavior of, for example, Rel.15 / 16 may be applied.

[0173] (Note) The following invention is added with respect to one embodiment of this disclosure.

[0174] [Note 1-1] A terminal comprising: a receiving unit that receives information about serving cells and candidate cells; and a control unit that, if multiple methods for obtaining timing advances corresponding to candidate cells are supported, obtains timing advances corresponding to candidate cells using a timing advance acquisition method selected based on at least one of a higher layer parameter and a predetermined rule. [Appendix 1-2] The terminal as described in Appendix 1-1, which, when acquiring a timing advance corresponding to a candidate cell based on a DL signal transmitted from the candidate cell, controls the control unit to acquire a timing advance corresponding to the candidate cell before or after receiving a cell switching command for the candidate cell. [Appendix 1-3] The control unit is a terminal as described in Appendix 1-1 or Appendix 1-2, which applies a timing advance corresponding to the candidate cell obtained based on the DL signal transmitted from the candidate cell when the cell switching command for the candidate cell does not include a timing advance value. [Appendix 1-4] When a timing advance corresponding to the candidate cell is obtained based on the DL signal transmitted from the candidate cell, the control unit applies the obtained timing advance to the first UL transmission sent to the candidate cell after receiving a cell switching command for the candidate cell, as described in any of the terminals in Appendix 1-1 to 1-3.

[0175] [Note 2-1] A terminal comprising: a receiving unit that receives information about one or more candidate cells; and a control unit that acquires a timing advance corresponding to the candidate cell based on the difference in reception timing of DL signals transmitted from a reference cell and the one or more candidate cells, wherein, when multiple candidate cells are set, the reference cell is set in common for the multiple candidate cells or set for each of the multiple candidate cells. [Note 2-2] The control unit is the terminal described in Appendix 2-1, which determines whether a predetermined offset is applied in the calculation of the timing advance corresponding to the candidate cell based on whether the reference cell and the candidate cell are synchronized or asynchronous. [Appendix 2-3] When a cell switching instruction is given for the serving cell that serves as the reference cell, the control unit does not change the reference cell even after the cell switching instruction is given for the terminal as described in Appendix 2-1 or Appendix 2-2. [Appendix 2-4] When a cell switch is instructed for the serving cell that serves as the reference cell, the control unit changes the reference cell even after the cell switch instruction, as described in any of the terminals in Appendix 2-1 to Appendix 2-3.

[0176] (Wireless communication system) The configuration of a wireless communication system according to one embodiment of this disclosure will be described below. In this wireless communication system, communication is performed using any or a combination thereof of the wireless communication methods according to the above embodiments of this disclosure.

[0177] Figure 18 shows an example of a schematic configuration of a wireless communication system according to one embodiment. Wireless communication system 1 (which may also be simply called system 1) may be a system that realizes communication using Long Term Evolution (LTE), 5th generation mobile communication system New Radio (5G NR), etc., as specified by the Third Generation Partnership Project (3GPP).

[0178] Furthermore, the wireless communication system 1 may 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)), and so on.

[0179] In EN-DC, the LTE (E-UTRA) base station (eNB) is the Master Node (MN), and the NR base station (gNB) is the Secondary Node (SN). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

[0180] The wireless communication system 1 may support dual connectivity between multiple base stations within the same RAT (for example, dual connectivity where both MN and SN are NR base stations (gNB) (NR-NR Dual Connectivity (NN-DC))).

[0181] The wireless communication system 1 may include a base station 11 that forms a macrocell C1 with relatively wide coverage, and base stations 12 (12a-12c) located within the macrocell C1 that form a small cell C2 that is narrower than the macrocell C1. User terminals 20 may be located within at least one cell. The arrangement and number of each cell and user terminal 20 are not limited to the configuration shown in the figure. Hereinafter, when base stations 11 and 12 are not distinguished, they will be collectively referred to as base station 10.

[0182] The user terminal 20 may be connected to at least one of the multiple base stations 10. The user terminal 20 may utilize at least one of Carrier Aggregation (CA) using multiple Component Carriers (CC) and Dual Connectivity (DC).

[0183] Each CC may be included in at least one of the first frequency band (Frequency Range 1 (FR1)) and the second frequency band (Frequency Range 2 (FR2)). A macrocell C1 may be included in FR1, and a small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band above 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and for example, FR1 may fall in a frequency band higher than FR2.

[0184] Furthermore, the user terminal 20 may communicate using at least one of the following methods at each CC: Time Division Duplex (TDD) and Frequency Division Duplex (FDD).

[0185] Multiple base stations 10 may be connected by wire (e.g., optical fiber compliant with Common Public Radio Interface (CPRI), X2 interface, etc.) or wireless (e.g., NR communication). For example, if NR communication is used as a backhaul between base stations 11 and 12, base station 11, which is the upstream station, may be called an Integrated Access Backhaul (IAB) donor, and base station 12, which is the relay station, may be called an IAB node.

[0186] Base station 10 may be connected to the core network 30 via other base stations 10 or directly. The core network 30 may include at least one of the following: Evolved Packet Core (EPC), 5G Core Network (5GCN), Next Generation Core (NGC), etc.

[0187] The core network 30 may include network functions (NF) such as User Plane Function (UPF), Access and Mobility Management Function (AMF), Session Management Function (SMF), Unified Data Management (UDM), Application Function (AF), Data Network (DN), Location Management Function (LMF), and Operation, Administration and Maintenance (Management) (OAM). Multiple functions may be provided by a single network node. Furthermore, communication with an external network (e.g., the Internet) may occur via the DN.

[0188] The user terminal 20 may be a terminal that supports at least one of the following communication methods: LTE, LTE-A, 5G, etc.

[0189] In the wireless communication system 1, an orthogonal frequency division multiplexing (OFDM)-based wireless access scheme may be used. 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), etc., may be used in at least one of the downlink (DL) and uplink (UL).

[0190] The wireless access method may also be called a waveform. In wireless communication system 1, other wireless access methods (for example, other single-carrier transmission methods, other multi-carrier transmission methods) may be used for the UL and DL wireless access methods.

[0191] In the wireless communication system 1, a Physical Downlink Shared Channel (PDSCH), a Broadcast Channel (PBCH), or a Physical Downlink Control Channel (PDCCH) may be used as the downlink channel, shared by each user terminal 20.

[0192] Furthermore, in the wireless communication system 1, the uplink channel may include a Physical Uplink Shared Channel (PUSCH), a Physical Uplink Control Channel (PUCCH), a Physical Random Access Channel (PRACH), or the like, all of which are shared by each user terminal 20.

[0193] User data, higher-layer control information, and System Information Blocks (SIBs) are transmitted via PDSCH. User data and higher-layer control information may also be transmitted via PUSCH. Furthermore, Master Information Blocks (MIBs) may be transmitted via PBCH.

[0194] Lower-layer control information may be transmitted by PDCCH. The lower-layer control information may include, for example, Downlink Control Information (DCI) which includes scheduling information for at least one of PDSCH and PUSCH.

[0195] Furthermore, the DCI that schedules PDSCH may be called a DL assignment or DL ​​DCI, and the DCI that schedules PUSCH may be called a UL grant or UL DCI. Furthermore, PDSCH may be interpreted as DL data, and PUSCH may be interpreted as UL data.

[0196] PDCCH detection may utilize a Control Resource Set (CORESET) and a search space. A CORESET corresponds to the resources used to search for DCIs. A search space corresponds to the search area and search method for PDCCH candidates. A single CORESET may be associated with one or more search spaces. The UE may monitor CORESETs associated with a particular search space based on the search space configuration.

[0197] A single search space may correspond to one or more PDCCH candidates corresponding to aggregation levels. One or more search spaces may be referred to as a search space set. In this disclosure, "search space," "search space set," "search space configuration," "search space set configuration," "CORESET," and "CORESET configuration" may be interpreted interchangeably.

[0198] PUCCH may transmit uplink control information (UCI) which includes at least one of the following: channel state information (CSI), delivery acknowledgment (e.g., Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK / NACK, etc.), and scheduling request (SR). PRACH may transmit a random access preamble for establishing a connection with the cell.

[0199] In this disclosure, downlinks, uplinks, etc., may be expressed without the prefix "link." Also, the prefix "physical" may be omitted when describing various channels.

[0200] 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 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.

[0201] 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 SS (PSS, SSS) and PBCH (and DMRS for PBCH) may be called an SS / PBCH block, SS Block (SSB), etc. SS, SSB, etc., may also be called reference signals.

[0202] Furthermore, in the wireless communication system 1, the Uplink Reference Signal (UL-RS) may transmit the Sounding Reference Signal (SRS), Demodulation Reference Signal (DMRS), etc. The DMRS may also be called the User-Specific Reference Signal (UE-specific Reference Signal).

[0203] (base station) Figure 19 shows an example of the configuration of a base station according to one embodiment. The base station 10 includes a control unit 110, a transceiver unit 120, a transceiver antenna 130, and a transmission line interface 140. Note that one or more of the control unit 110, transceiver unit 120, transceiver antenna 130, and transmission line interface 140 may be provided.

[0204] In this example, the functional blocks of the characteristic parts of this 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 part described below may be omitted.

[0205] The control unit 110 controls the entire base station 10. The control unit 110 can be composed of a controller, control circuit, etc., as described based on common understanding in the art relating to this disclosure.

[0206] The control unit 110 may control signal generation, scheduling (e.g., resource allocation, mapping), etc. The control unit 110 may also control transmission and reception, measurement, etc., using the transceiver unit 120, the transceiver antenna 130, and the transmission path interface 140. The control unit 110 may generate data to be transmitted as signals, control information, sequences, etc., and transfer them to the transceiver unit 120. The control unit 110 may also perform call processing of communication channels (setting, releasing, etc.), status management of the base station 10, management of radio resources, etc.

[0207] The transmitting / receiving 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 transmitting / receiving unit 120 can be composed of a transmitter / receiver, RF circuit, baseband circuit, filter, phase shifter, measurement circuit, transmitting / receiving circuit, etc., as described based on common understanding in the art relating to this disclosure.

[0208] The transmitting / receiving unit 120 may be configured as an integrated transmitting / receiving unit, or it may be composed of a transmitting unit and a receiving unit. The transmitting unit may consist of a transmitting processing unit 1211 and an RF unit 122. The receiving unit may consist of a receiving processing unit 1212, an RF unit 122 and a measuring unit 123.

[0209] The transmitting and receiving antenna 130 can be composed of an antenna described based on common understanding in the art relating to this disclosure, such as an array antenna.

[0210] The transmitting / receiving unit 120 may transmit the downlink channel, synchronization signal, downlink reference signal, etc. The transmitting / receiving unit 120 may also receive the uplink channel, uplink reference signal, etc.

[0211] The transmitting / receiving unit 120 may form at least one of the transmitting beam and the receiving beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0212] The transmitting / receiving unit 120 (transmission processing unit 1211) may perform processing on data and control information acquired from the control unit 110, for example, at the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer (e.g., RLC retransmission control), the Medium Access Control (MAC) layer (e.g., HARQ retransmission control), etc., to generate a bit sequence to be transmitted.

[0213] The transmitting / receiving unit 120 (transmission processing unit 1211) may perform transmission processing on the bit sequence to be transmitted, 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, and output a baseband signal.

[0214] The transmitting / receiving unit 120 (RF unit 122) may perform modulation, filtering, amplification, etc., of the baseband signal to the radio frequency band and transmit the signal in the radio frequency band via the transmitting / receiving antenna 130.

[0215] 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.

[0216] The transmitting / receiving unit 120 (receiving processing unit 1212) may apply reception processing to the acquired baseband signal, such as analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (if necessary), filtering, demapping, demodulation, decoding (may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing, to acquire user data, etc.

[0217] The transmitting / receiving unit 120 (measurement unit 123) may perform measurements related to 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 also measure received power (e.g., Reference Signal Received Power (RSRP)), reception 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.

[0218] The transmission path interface 140 may send and receive signals (backhaul signaling) with devices included in the core network 30 (e.g., network nodes providing NF), other base stations 10, etc., and may acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0219] In this disclosure, the transmitting and receiving units of the base station 10 may consist of at least one of a transmitting / receiving unit 120, a transmitting / receiving antenna 130, and a transmission path interface 140.

[0220] The transmitting / receiving unit 120 may transmit information about the serving cell and information about the candidate cell. If multiple methods for obtaining the timing advance corresponding to the candidate cell are supported, the control unit 110 may use higher-layer parameters to instruct a specific method for obtaining the timing advance.

[0221] The transmitting / receiving unit 120 may transmit information about one or more candidate cells to the terminal. The control unit 110 may indicate the reference cell corresponding to one or more candidate cells when the terminal obtains a timing advance corresponding to a candidate cell based on the difference in reception timing of DL signals transmitted from the reference cell and one or more candidate cells, respectively.

[0222] (User terminal) Figure 20 shows an example of the configuration of a user terminal according to one embodiment. The user terminal 20 includes a control unit 210, a transmitting / receiving unit 220, and a transmitting / receiving antenna 230. Note that one or more of the control unit 210, the transmitting / receiving unit 220, and the transmitting / receiving antenna 230 may be provided.

[0223] In this example, the functional blocks of the characteristic parts of this 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 part described below may be omitted.

[0224] The control unit 210 controls the entire user terminal 20. The control unit 210 can be composed of a controller, control circuit, etc., as described based on common understanding in the technical field related to this disclosure.

[0225] The control unit 210 may control signal generation, mapping, etc. The control unit 210 may also control transmission and reception, measurement, etc., using the transmitting / receiving unit 220 and the transmitting / receiving antenna 230. The control unit 210 may generate data to be transmitted as signals, control information, sequences, etc., and transfer them to the transmitting / receiving unit 220.

[0226] The transmitting / receiving unit 220 may include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may include a transmission processing unit 2211 and a reception processing unit 2212. The transmitting / receiving unit 220 can be composed of a transmitter / receiver, RF circuit, baseband circuit, filter, phase shifter, measurement circuit, transmitting / receiving circuit, etc., as described based on common understanding in the art relating to this disclosure.

[0227] The transmitting / receiving unit 220 may be configured as an integrated transmitting / receiving unit, or it may be composed of a transmitting unit and a receiving unit. The transmitting unit may consist of a transmitting processing unit 2211 and an RF unit 222. The receiving unit may consist of a receiving processing unit 2212, an RF unit 222 and a measuring unit 223.

[0228] The transmitting and receiving antenna 230 can be composed of an antenna described based on common understanding in the art relating to this disclosure, such as an array antenna.

[0229] The transmitting / receiving unit 220 may receive the downlink channel, synchronization signal, downlink reference signal, etc. The transmitting / receiving unit 220 may also transmit the uplink channel, uplink reference signal, etc.

[0230] The transmitting / receiving unit 220 may form at least one of the transmitting beam and the receiving beam using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), or the like.

[0231] The transmitting / receiving 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 and control information acquired from the control unit 210, etc., to generate a bit sequence to be transmitted.

[0232] The transmitting / receiving unit 220 (transmission processing unit 2211) may perform transmission processing on the bit sequence to be transmitted, 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, and output a baseband signal.

[0233] Whether or not to apply DFT processing may be based on the transform precoding settings. The transmitting / receiving unit 220 (transmission processing unit 2211) may perform DFT processing as part of the transmission process to transmit a channel (for example, PUSCH) using a DFT-s-OFDM waveform if transform precoding is enabled for that channel, or it may not perform DFT processing as part of the transmission process if transform precoding is not enabled for that channel.

[0234] The transmitting / receiving unit 220 (RF unit 222) may perform modulation, filtering, amplification, etc., of the baseband signal to the radio frequency band and transmit the signal in the radio frequency band via the transmitting / receiving antenna 230.

[0235] On the other hand, the transmitting / receiving unit 220 (RF unit 222) may perform amplification, filtering, demodulation to a baseband signal, etc., on the radio frequency band signal received by the transmitting / receiving antenna 230.

[0236] The transmitting / receiving unit 220 (receiving processing unit 2212) may apply reception processing such as analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filtering, demapping, demodulation, decoding (may include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing to the acquired baseband signal to acquire user data, etc.

[0237] The transmitting / receiving unit 220 (measuring unit 223) may perform measurements related to the received signal. For example, the measuring unit 223 may perform RRM measurement, CSI measurement, etc., based on the received signal. The measuring unit 223 may also 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.

[0238] The measurement unit 223 may derive channel measurements for CSI calculation based on channel measurement resources. Channel measurement resources may be, for example, Non Zero Power (NZP) CSI-RS resources. The measurement unit 223 may also derive interference measurements for CSI calculation based on interference measurement resources. Interference measurement resources may be at least one of the following: an NZP CSI-RS resource for interference measurement, a CSI-Interference Measurement (IM) resource, etc. CSI-IM may also be called CSI-Interference Management (IM), and may be interpreted interchangeably with Zero Power (ZP) CSI-RS. In this disclosure, CSI-RS, NZP CSI-RS, ZP CSI-RS, CSI-IM, CSI-SSB, etc., may be interpreted interchangeably.

[0239] In this disclosure, the transmitting and receiving units of the user terminal 20 may consist of at least one of a transmitting / receiving unit 220 and a transmitting / receiving antenna 230.

[0240] The transmitting / receiving unit 220 may receive information about serving cells and information about candidate cells. If multiple methods for obtaining timing advances corresponding to candidate cells are supported, the control unit 210 may obtain timing advances corresponding to candidate cells using a timing advance acquisition method selected based on at least one of the upper layer parameters and predetermined rules.

[0241] When acquiring a timing advance corresponding to a candidate cell based on a DL signal transmitted from the candidate cell, the control unit 210 may control the system to acquire the timing advance corresponding to the candidate cell before or after receiving a cell switching command for the candidate cell. If the cell switching command for the candidate cell does not include a timing advance value, the control unit 210 may apply the timing advance corresponding to the candidate cell acquired based on the DL signal transmitted from the candidate cell. When acquiring a timing advance corresponding to a candidate cell based on a DL signal transmitted from the candidate cell, the control unit 210 may apply the acquired timing advance to the first UL transmission sent to the candidate cell after receiving a cell switching command for the candidate cell.

[0242] The transmitting / receiving unit 220 may receive information about one or more candidate cells. The control unit 210 may acquire a timing advance corresponding to a candidate cell based on the difference in reception timing of DL signals transmitted from the reference cell and one or more candidate cells, respectively. When multiple candidate cells are set, the reference cell may be set in common for multiple candidate cells, or it may be set for each of the multiple candidate cells.

[0243] The control unit 210 may determine whether to apply a predetermined offset in the calculation of the timing advance corresponding to a candidate cell based on whether the reference cell and the candidate cell are synchronized or asynchronous. If a cell switch is instructed for the serving cell that will be the reference cell, the control unit 210 may control the system so as not to change the reference cell even after the cell switch instruction. If a cell switch is instructed for the serving cell that will be the reference cell, the control unit 210 may control the system so as to change the reference cell even after the cell switch instruction.

[0244] (Hardware configuration) It should be noted that the block diagrams used in the description of the above embodiments show blocks in functional units. These functional blocks (components) are implemented by any combination of at least one of hardware and software. In addition, the method of implementing each functional block is not particularly limited. That is, each functional block may be implemented by using one physically or logically coupled device, or may be implemented by directly or indirectly connecting two or more physically or logically separated devices (e.g., using wired connection, wireless connection, etc.) and using the plurality of devices. A functional block may be implemented by combining software with the one device or the plurality of devices described above.

[0245] Here, functions include, but are not limited to: judging, determining, processing, calculating, computing, deriving, investigating, searching, checking, receiving, transmitting, outputting, accessing, resolving, selecting, choosing, establishing, comparing, assuming, expecting, deeming, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), assigning, and the like. For example, a functional block (component) that enables transmission may be referred to as a transmitting unit, a transmitter, or the like. In any case, as described above, the implementation method is not particularly limited.

[0246] For example, a base station, a user terminal, and the like in one embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. FIG. 21 is a diagram showing an example of a hardware configuration of a base station and a user terminal according to one embodiment. The above-described base station 10 and user terminal 20 may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

[0247] In the present disclosure, terms such as apparatus, circuit, device, section, and unit may be read interchangeably with each other. The hardware configuration of base station 10 and user terminal 20 may be configured to include one or more of each apparatus shown in the figure, or may be configured without including some of the apparatuses.

[0248] For example, although only one processor 1001 is illustrated, there may be a plurality of processors. Further, processing may be executed by one processor, or may be executed by two or more processors simultaneously, sequentially, or using other methods. Note that processor 1001 may be implemented by one or more chips.

[0249] Each function in base station 10 and user terminal 20 is implemented, for example, by loading predetermined software (program) onto hardware such as processor 1001 and memory 1002, whereby processor 1001 performs calculations, controls communication via communication apparatus 1004, and controls at least one of reading and writing of data in memory 1002 and storage 1003.

[0250] For example, processor 1001 operates an operating system to control the entire computer. Processor 1001 may be configured by a Central Processing Unit (CPU) including an interface with peripheral devices, a control unit, an arithmetic unit, registers, and the like. For example, at least part of the above-described control unit 110 (210), transmission / reception unit 120 (220), and the like may be implemented by processor 1001.

[0251] Furthermore, the processor 1001 reads programs (program code), 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 accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. 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 other functional blocks may be implemented similarly.

[0252] Memory 1002 is a computer-readable recording medium and may consist of at least one of the following: Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. Memory 1002 may also be called a register, cache, or main memory. Memory 1002 can store executable programs (program code), software modules, etc., for carrying out a wireless communication method according to one embodiment of this disclosure.

[0253] Storage 1003 is a computer-readable recording medium and may consist of at least one of the following: a flexible disk, a floppy disk, a magneto-optical disk (e.g., a compact disk (Compact Disc ROM (CD-ROM)), a digital multipurpose disk, a Blu-ray disk), a removable disk, a hard disk drive, a smart card, a flash memory device (e.g., a card, stick, key drive), a magnetic stripe, a database, a server, or other suitable storage medium. Storage 1003 may also be called an auxiliary storage device.

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

[0255] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, light-emitting diode (LED) lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

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

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

[0258] (modified version) In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, channel, symbol, and signal (signal or signaling) may be used interchangeably. Also, a signal may be a message. A reference signal may be abbreviated as RS and may be called a pilot, pilot signal, etc., depending on the applicable standard. Also, a component carrier (CC) may be called a cell, frequency carrier, carrier frequency, etc.

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

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

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

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

[0263] Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Wireless frames, subframes, slots, minislots, and symbols may each be referred to by different names. Furthermore, the units of time such as frames, subframes, slots, minislots, and symbols in this disclosure may be interpreted as interchangeable.

[0264] For example, one subframe may be called TTI, multiple consecutive subframes may be called TTI, or one slot or one mini-slot may be called TTI. In other words, at least one of the subframe and TTI may be a subframe (1ms) in existing LTE, a period shorter than 1ms (e.g., 1-13 symbols), or a period longer than 1ms. Note that the unit representing TTI may be called a slot, mini-slot, etc., instead of a subframe.

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

[0266] TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. Given a TTI, the actual time interval (e.g., number of symbols) to which the transport block, code block, code word, etc. are mapped may be shorter than the given TTI.

[0267] Note that when 1 slot or 1 mini-slot is referred to as a TTI, one or more TTIs (i.e., one or more slots or one or more mini-slots) may serve as the minimum time unit for scheduling. The number of slots (the number of mini-slots) constituting the minimum time unit for said scheduling may also be controlled.

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

[0269] Note that a long TTI (e.g., a normal TTI, a subframe, etc.) may alternatively be interpreted as a TTI having a time length exceeding 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may alternatively be interpreted as a TTI having a TTI length less than the TTI length of a long TTI and greater than or equal to 1 ms.

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

[0271] Furthermore, an RB may include one or more symbols in the time domain, and may have a length of 1 slot, 1 mini-slot, 1 subframe or 1 TTI. One TTI, one subframe, or the like may each be constituted by one or more resource blocks.

[0272] One or more RBs may also be called Physical RBs (PRBs), Sub-Carrier Groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB pairs, etc.

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

[0274] A Bandwidth Part (BWP) (also called a partial bandwidth) may represent a subset of consecutive common resource blocks (RBs) for a given neurology in a given carrier. Here, the common RBs may be identified by an index of the RBs relative to the carrier's common reference point. PRBs may be defined and numbered within a BWP.

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

[0276] At least one of the configured BWPs may be active, and the UE does not need to assume that it will send or receive a given signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0277] The structures described above, such as wireless frames, subframes, slots, minislots, and symbols, are merely illustrative examples. For instance, the number of subframes included in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots within a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, and the number of symbols, symbol length, and cyclic prefix (CP) length within a TTI can be varied in various ways.

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

[0279] The names used for parameters and other elements in this disclosure are not restrictive in any way. Furthermore, mathematical formulas and other elements that use these parameters may differ from those expressly disclosed in this disclosure. Various channels (PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, and therefore, the various names assigned to these various channels and information elements are not restrictive in any way.

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

[0281] Furthermore, information, signals, etc., can be output from upper layers to lower layers and from lower layers to upper layers, or to at least one of the two. Information, signals, etc., may also be input and output via multiple network nodes.

[0282] Input and output information and signals may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information and signals may be overwritten, updated, or appended to. Output information and signals may be deleted. Input information and signals may be transmitted to other devices.

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

[0284] Physical layer signaling may also be called Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signals), L1 control information (L1 control signals), etc. RRC signaling may also be called RRC messages, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc. MAC signaling may also be communicated using, for example, MAC Control Element (CE).

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

[0286] The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value represented as true or false, or by a numerical comparison (for example, a comparison with a predetermined value).

[0287] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0288] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or Digital Subscriber Line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0289] The terms “system” and “network” as used in this disclosure may be used interchangeably. “Network” may also mean the equipment included in the network (e.g., base stations).

[0290] In this disclosure, terms such as “precoding,” “precoder,” “weight (precoding weight),” “quasi-co-location (QCL),” “transmission configuration indication state (TCI state),” “spatial relation,” “spatial domain filter,” “transmit power,” “phase rotation,” “antenna port,” “layer,” “number of layers,” “rank,” “resource,” “resource set,” “beam,” “beam width,” “beam angle,” “antenna,” “antenna element,” “panel,” “UE panel,” “transmitting entity,” and “receiving entity” may be used interchangeably.

[0291] In this disclosure, "antenna port" may be interpreted interchangeably with "antenna port for any signal / channel" (e.g., a Demodulation Reference Signal (DMRS) port). In this disclosure, "resource" may be interpreted interchangeably with "resource for any signal / channel" (e.g., a reference signal resource, an SRS resource, etc.). Resources may include time / frequency / code / spatial / power resources. Furthermore, a spatial domain transmit filter may include at least one of a spatial domain transmit filter and a spatial domain receive filter.

[0292] The above group may include, for example, at least one of the following: a spatial relationship group, a code division multiplexing (CDM) group, a reference signal (RS) group, a control resource set (CORESET) group, a PUCCH group, an antenna port group (e.g., a DMRS port group), a layer group, a resource group, a beam group, an antenna group, or a panel group.

[0293] Furthermore, in this disclosure, beam, SRS Resource Indicator (SRI), CORESET, CORESET pool, PDSCH, PUSCH, Codeword (CW), Transport Block (TB), RS, etc., may be interpreted as being interchangeable.

[0294] Furthermore, in this disclosure, TCI state, downlink TCI state (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, joint TCI state, etc., may be interpreted interchangeably.

[0295] Furthermore, in this disclosure, terms such as "QCL," "QCL assumption," "QCL relationship," "QCL type information," "QCL properties," "specific QCL type (e.g., type A, type D) properties," and "specific QCL type (e.g., type A, type D)" may be interpreted as interchangeable.

[0296] In this disclosure, terms such as index, identifier (ID), indicator, indication, and resource ID may be interpreted interchangeably. In this disclosure, terms such as sequence, list, set, group, cluster, subset, etc., may be interpreted interchangeably.

[0297] Furthermore, the spatial relationship information Identifier (ID) (TCI state ID) and spatial relationship information (TCI state) may be interpreted as mutually exclusive. "Spatial relationship information (TCI state)" may be interpreted as mutually exclusive as "a set of spatial relationship information (TCI state)," "one or more spatial relationship information," etc. TCI state and TCI may be interpreted as mutually exclusive. Spatial relationship information and spatial relationship may be interpreted as mutually exclusive.

[0298] In this disclosure, terms such as "Base Station (BS)", "wireless 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", and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0299] A base station can house one or more (e.g., three) cells. If a base station houses multiple cells, the entire coverage area of ​​the base station can be divided into several smaller areas, each of which may also be provided with communication services 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 ​​at least one of the base station and / or base station subsystems that provide communication services in that coverage.

[0300] In this disclosure, the transmission of information by a base station to a terminal may be interpreted as the base station instructing the terminal to perform a control / operation based on said information.

[0301] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0302] A mobile station may also be called 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 appropriate term.

[0303] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a wireless communication device, etc. At least one of the base station and the mobile station may also be a device mounted on a moving object, the moving object itself, etc.

[0304] The term "mobile object" refers to any movable object, regardless of its speed, and naturally includes cases where the mobile object is stationary. Examples of such mobile objects include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and items carried on them. Furthermore, such mobile objects may be autonomously driven objects operating based on operational commands.

[0305] The mobile entity may be a vehicle (e.g., a car, an airplane), an unmanned mobile entity (e.g., a drone, an autonomous vehicle), or a robot (manned or unmanned). At least one of the base station and the mobile station may be a device that does 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.

[0306] Figure 22 shows an example of a vehicle according to one 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, an axle 48, an electronic control unit 49, various sensors (including a current sensor 50, a rotation speed sensor 51, a pneumatic 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.

[0307] The drive unit 41 consists of, for example, at least one of an engine, a motor, or an engine-motor hybrid. The steering unit 42 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels 46 and the rear wheels 47 based on the operation of the steering wheel operated by the user.

[0308] The electronic control unit 49 consists of a microprocessor 61, memory (ROM, RAM) 62, and communication ports (e.g., input / output (IO) ports) 63. Signals from various sensors 50-58 installed in the vehicle are input to the electronic control unit 49. The electronic control unit 49 may also be called an Electronic Control Unit (ECU).

[0309] Signals from various sensors 50-58 include current signals from current sensor 50 for sensing motor current, rotational speed signals of front wheels 46 / rear wheels 47 acquired by rotational speed sensor 51, air pressure signals of front wheels 46 / rear wheels 47 acquired by air pressure sensor 52, vehicle speed signals acquired by vehicle speed sensor 53, acceleration signals acquired by acceleration sensor 54, accelerator pedal depression signal of accelerator pedal 43 acquired by accelerator pedal sensor 55, brake pedal depression signal of brake pedal 44 acquired by brake pedal sensor 56, operation signals of shift lever 45 acquired by shift lever sensor 57, and detection signals for detecting obstacles, vehicles, pedestrians, etc., acquired by object detection sensor 58.

[0310] The information service unit 59 consists of various devices for providing (outputting) various types of information such as driving information, traffic information, and entertainment information, including a car navigation system, audio system, speakers, displays, television, and radio, and one or more ECUs that control these devices. The information service unit 59 uses information acquired from external devices via a communication module 60 or the like to provide various types of information / services (e.g., multimedia information / multimedia services) to the occupants of the vehicle 40.

[0311] The information service unit 59 may include input devices that accept input from the outside (e.g., keyboard, mouse, microphone, switch, button, sensor, touch panel, etc.) and output devices that perform output to the outside (e.g., display, speaker, LED lamp, touch panel, etc.).

[0312] The driver assistance system unit 64 consists of various devices that provide functions to prevent accidents or reduce the driver's workload, 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 Unit (IMU), Inertial Navigation System (INS)), artificial intelligence (AI) chips, and AI processors, as well as one or more ECUs that control these devices. The driver assistance system unit 64 also transmits and receives various information via the communication module 60 to realize driver assistance functions or autonomous driving functions.

[0313] 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 sends and receives data (information) via the communication port 63 to 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, axle 48, the microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49, and various sensors 50-58 provided in the vehicle 40.

[0314] 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 external devices. For example, it can send and receive various types of information to and from external devices 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. Alternatively, the communication module 60 may be, for example, at least one of the base station 10 and the user terminal 20 (it may function as at least one of the base station 10 and the user terminal 20).

[0315] The communication module 60 may transmit at least one of the following to an external device via wireless communication: signals from the various sensors 50-58 input to the electronic control unit 49, information obtained based on said signals, and information based on input from an external source (user) obtained via the information service unit 59. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc., may also be called input units that accept input. For example, the PUSCH transmitted by the communication module 60 may include information based on the above input.

[0316] The communication module 60 receives various information (traffic information, signal information, inter-vehicle information, etc.) transmitted from an external device and displays it on the information service unit 59 installed in the vehicle. The information service unit 59 may also be called an output unit, which outputs information (for example, it outputs information to devices such as displays and speakers based on the PDSCH (or data / information decoded from the PDSCH) received by the communication module 60).

[0317] 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, axle 48, various sensors 50-58, etc., which are provided in the vehicle 40.

[0318] Furthermore, the term "base station" in this disclosure may be interpreted as "user terminal." For example, the various aspects / embodiments of this 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), Vehicle-to-Everything (V2X)). In this case, the user terminal 20 may have the functions that the base station 10 has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "sidelink"). For example, uplink channel and downlink channel may be interpreted as sidelink channel.

[0319] Similarly, the term "user terminal" in this disclosure may be replaced with "base station." In this case, the base station 10 may be configured to have the same functions as the user terminal 20 described above.

[0320] In this disclosure, operations performed by a base station may, in some cases, be performed by its upper node. In a network including one or more network nodes with base stations, it is clear that various operations performed for communication with terminals may be performed by the base station, one or more network nodes other than the base station (for example, a Mobility Management Entity (MME), a Serving Gateway (S-GW), etc., but not limited to these), or a combination thereof.

[0321] Each aspect / embodiment described in this disclosure may be used individually, in combination, or switched between during execution. Furthermore, the processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described in this disclosure may be rearranged in order, provided they are consistent. For example, the methods described in this disclosure present various step elements in an exemplary order and are not limited to that specific order.

[0322] Each aspect / embodiment described in this disclosure includes 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 (where x is, for example, an integer or decimal)), 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®), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), and IEEE This may apply to systems utilizing 802.20, Ultra-WideBand (UWB), Bluetooth®, or other appropriate wireless communication methods, as well as next-generation systems that are extended, modified, created, or defined based on these. It may also apply to combinations of multiple systems (e.g., a combination of LTE or LTE-A and 5G).

[0323] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0324] Any reference to elements using the designations “first,” “second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, the references to the first and second elements do not imply that only two elements may be employed or that the first element must precede the second element in any way.

[0325] The term “determining” as used in this disclosure may encompass a wide variety of actions. For example, “determining” may be considered to include judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiry (e.g., searching in tables, databases, or other data structures), ascertaining, etc.

[0326] Furthermore, "judgment (decision)" may be considered as "judging (deciding)" things like receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory).

[0327] Furthermore, "judgment (decision)" may be considered as "judging (deciding)" something like resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment (decision)" may be considered as "judging (deciding)" something about an action. In this disclosure, "judgment (decision)" may be interpreted interchangeably with the actions described above.

[0328] Furthermore, in this disclosure, “determine / determining” may be interpreted as “assume / assuming,” “expect / expecting,” or “consider / considering.” In addition, in this disclosure, “not assuming that…” may be interpreted as “assuming that…”

[0329] In this disclosure, “expect” may be interpreted as “be expected.” For example, “expect(s) …” (where “...” may be expressed as a that clause, an infinitive, etc.) may be interpreted as “be expected ….” “does not expect …” may be interpreted as “be not expected ….” Furthermore, “An apparatus A is not expected …” may be interpreted as “An apparatus B other than apparatus A does not expect …” (for example, if apparatus A is a UE, apparatus B may be a base station).

[0330] The term "maximum transmit power" as used in this disclosure may mean the maximum value of the transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

[0331] As used in this disclosure, the terms “connected,” “coupled,” and any variations thereof mean any direct or indirect connection or coupling between two or more elements, and may include one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be replaced with “access.”

[0332] In this disclosure, when two elements are connected, they can be considered to be “connected” or “coupled” to each other using one or more wires, cables, printed electrical connections, etc., and, in some non-exclusive and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, or optical domain (both visible and invisible).

[0333] In this 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 "combine" may be interpreted similarly to "different."

[0334] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0335] In this disclosure, if articles are added by translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0336] In this disclosure, terms such as "less than or equal to," "less than," "greater than or equal to," "more than," and "equal to" may be interpreted interchangeably. In addition, in this disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "early," "slow," "wide," and "narrow" may be interpreted interchangeably, not limited to the positive, comparative, and superlative degrees. Furthermore, in this disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "early," "slow," "wide," and "narrow" may be interpreted interchangeably, not limited to the positive, comparative, and superlative degrees, by adding "i-th" (where i is any integer) to the expression (for example, "highest" may be interpreted interchangeably with "i-th highest").

[0337] In this disclosure, "of," "for," "regarding," "related to," and "associated with" may be interpreted as being interchangeable.

[0338] In this disclosure, phrases such as "when A, B", "if A, then B", "B upon A", "B in response to A", "B based on A", "B during / while A", "B before A", "B at (the same time as) / on A", "B after A", "B since A", and "B until A" may be interchangeable. Furthermore, A, B, etc., may be replaced with appropriate expressions such as nouns, gerunds, or regular sentences depending on the context. The time difference between A and B may be approximately 0 (immediately after or immediately before). Additionally, a time offset may be applied to the time when A occurs. For example, "A" may be interpreted as "before / after the time offset when A occurs". The time offset (e.g., one or more symbols / slots) may be predetermined or determined by the UE based on the information provided.

[0339] In this disclosure, timing, time, duration, time instance, any unit of time (e.g., slot, subslot, symbol, subframe), period, occasion, resource, etc., may be interpreted interchangeably.

[0340] Although the invention described herein has been explained in detail above, it will be clear to those skilled in the art that the invention described herein is not limited to the embodiments described herein. The descriptions herein are illustrative and not intended to be restrictive in any way to the invention described herein.

Claims

1. A transmitter that reports the ability to support terminal-based timing advance (TA) measurement, A receiving unit receives a cell switching instruction via the Medium Access Control Control Element (MAC CE) that instructs switching to a candidate cell, A terminal having, if the MAC CE does not include the TA value of the candidate cell, a control unit that applies the TA measured by the terminal-based TA measurement to the uplink (UL) transmission in the candidate cell.

2. The terminal according to claim 1, wherein the MAC CE includes a first field indicating whether the value of TA exists.

3. The terminal according to claim 1, wherein the MAC CE includes a second field that instructs the activation of the Transmit Configuration Instruction (TCI) state of the candidate cell.

4. The terminal according to claim 1, wherein the control unit applies the TA measured by the terminal-based TA measurement to the UL transmission in the candidate cell after the cell switching instruction.

5. A step of reporting the ability to support terminal-based timing advance (TA) measurement, The process involves receiving a cell switching instruction via the Medium Access Control Control Element (MAC CE) that instructs switching to a candidate cell, A wireless communication method for a terminal, comprising the step of applying the TA measured by the terminal-based TA measurement to the uplink (UL) transmission in the candidate cell if the MAC CE does not include the TA value of the candidate cell.

6. A receiving unit that receives an indication of the ability to support terminal-based timing advance (TA) measurement, A transmission unit that sends a cell switching instruction to a candidate cell using the Medium Access Control Control Element (MAC CE), A base station having, if the MAC CE does not include the TA value of the candidate cell, a control unit that instructs the terminal-based TA measurement to measure the TA to be applied to uplink (UL) transmission in the candidate cell.

7. A system having a terminal and a base station, The terminal includes a transmitter that reports its ability to support terminal-based timing advance (TA) measurement, A receiving unit receives a cell switching instruction via the Medium Access Control Control Element (MAC CE) that instructs switching to a candidate cell, The MAC CE includes a control unit that, if the TA value of the candidate cell is not included, applies the TA measured by the terminal-based TA measurement to the uplink (UL) transmission in the candidate cell. The base station includes a receiving unit that receives the aforementioned capability, A transmitting unit that transmits the MAC CE, A system comprising: a control unit that instructs the TA to be measured by the terminal-based TA measurement.

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