Terminal, wireless communication method, and base station

Abstract

The present invention provides terminals, methods, and base stations that enable proper communication even when performing intra-cell or inter-cell mobility. [Solution] In a mobile communication system, a user terminal has a receiving unit that receives cell switching instruction information in intra-cell or inter-cell mobility that supports multiple transmit / receive points (TRPs), and a control unit that determines a timing advance (TA) to be applied to UL transmission based on the cell switching instruction information. The control unit determines a reference cell or reference TRP for deriving the TA based on whether or not a TRP of a specific cell is included in the timing advance group (TAG).

Description

[Technical Field]

[0001] This disclosure relates to terminals, wireless communication methods, and base stations in next-generation mobile communication systems. [Background technology]

[0002] Long Term Evolution (LTE) was specified for Universal Mobile Telecommunications System (UMTS) networks with the aim of achieving even higher data rates and lower latency (Non-Patent Literature 1). Furthermore, LTE-Advanced (3GPP Rel.10-14) was specified for the aim of further increasing capacity and sophistication of LTE (Third Generation Partnership Project (3GPP®) Release (Rel.) 8, 9).

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

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

[0005] Future wireless communication systems (e.g., wireless communication systems beyond Rel.17 / 5G) are expected to control communication using multiple transmit / receive points (e.g., Multi-TRP (MTRP)) in a serving cell, or to control communication based on inter-cell mobility / intra-cell mobility including non-serving cells.

[0006] In this case, it is conceivable that UL transmission control (e.g., implementation of random access procedures (or setting of timing advances)) may be performed for each transmitting / receiving point, or for each serving cell and non-serving cell. However, the problem lies in how a terminal (user terminal, User Equipment (UE)) controls UL transmission (e.g., timing advance control) for multiple transmitting / receiving points (or non-serving cells). If UL transmission to each transmitting / receiving point (or TRP of a serving / non-serving cell) is not properly controlled, the quality of communication may deteriorate.

[0007] This disclosure is made in view of the above, and one of its purposes is to provide a terminal, a wireless communication method, and a base station that can properly communicate even when performing intra-cell or inter-cell mobility. [Means for solving the problem]

[0008] A terminal according to one aspect of the present disclosure includes a receiving unit that receives cell switching instruction information in intra-cell or inter-cell mobility supporting multiple transmit / receive points (TRPs), and a control unit that determines a timing advance (TA) to be applied to UL transmission based on the cell switching instruction information, wherein the control unit determines a reference cell or reference TRP for deriving the TA based on whether or not a TRP of a specific cell is included in a timing advance group (TAG). [Effects of the Invention]

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

[0010] [Figure 1] Figures 1A-1D show an example of a multi-TRP. [Figure 2] Figures 2A and 2B show an example of inter-cell mobility. [Figure 3] Figures 3A and 3B show an example of switching between a serving cell and an additional cell using L1 / L2 signaling. [Figure 4] Figure 4 shows an example of settings 1-3 when candidate cells are supported. [Figure 5] Figures 5A-5C illustrate 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 6] Figure 6 shows an example of a Timing Advance Group (TAG) to which a cell group belongs. [Figure 7] Figure 7 shows an example of a MAC CE for timing advance commands. [Figure 8] Figures 8A and 8B show examples of TAG IDs set for serving cells and candidate cells. [Figure 9]Figs. 9A-9C are diagrams showing application examples of a reference cell according to the first embodiment. [Figure 10] Figs. 10A-10C are diagrams showing application examples of a reference cell according to the first embodiment. [Figure 11] Figs. 11A-11C are diagrams showing application examples of a reference cell according to the second embodiment. [Figure 12] Figs. 12A-12C are diagrams showing application examples of a reference cell according to the second embodiment. [Figure 13] Figs. 13A-13B are diagrams showing application examples of a reference cell according to the third embodiment. [Figure 14] Figs. 14A-14B are diagrams showing application examples of a reference cell according to the third embodiment. [Figure 15] Fig. 15 is a diagram showing an example of a schematic configuration of a wireless communication system according to an embodiment. [Figure 16] Fig. 16 is a diagram showing an example of a configuration of a base station according to an embodiment. [Figure 17] Fig. 17 is a diagram showing an example of a configuration of a user terminal according to an embodiment. [Figure 18] Fig. 18 is a diagram showing an example of a hardware configuration of a base station and a user terminal according to an embodiment. [Figure 19] Fig. 19 is a diagram showing an example of a vehicle according to an embodiment.

Embodiments for Carrying Out the Invention

[0011] (TCI, Spatial Relationship, QCL) In NR, based on the Transmission Configuration Indication state (TCI state), it is considered to control at least one of signal and channel (expressed as signal / channel) in a UE, including at least one of reception processing (e.g., at least one of reception, demapping, demodulation, decoding), and transmission processing (e.g., at least one of transmission, mapping, precoding, modulation, encoding).

[0012] The TCI state may represent the one applied to the downlink signal / channel. The equivalent of the TCI state applied to the 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 AD 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] 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.

[0021] 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).

[0022] 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)).

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

[0024] 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.

[0025] (Multi-TRP) In NR, it is being considered that one or more transmission / reception points (TRPs) (multi-TRPs) will use one or more panels (multi-panels) to perform DL transmissions to the UE. Furthermore, it is being considered that the UE will perform UL transmissions to one or more TRPs.

[0026] Multiple TRPs may correspond to the same cell identifier (Cell Identifier (ID)) or to different cell IDs. This cell ID may be a physical cell ID (e.g., PCI) or a virtual cell ID.

[0027] Figures 1A-1D show examples of multi-TRP scenarios. In these examples, it is assumed, but not limited to, that each TRP can transmit four different beams.

[0028] Figure 1A shows an example of a case where only one TRP (TRP1 in this example) among the multi-TRPs transmits to the UE (this may also be called single-mode or single-TRP). In this case, TRP1 transmits both control signals (PDCCH) and data signals (PDSCH) to the UE.

[0029] In this disclosure, single TRP mode may mean the mode in which multi-TRP(mode) is not set.

[0030] Figure 1B shows an example of a case where only one of the multi-TRPs (TRP1 in this example) transmits control signals to the UE, and that multi-TRP transmits data signals (this may also be called single-master mode). The UE receives each PDSCH transmitted from the multi-TRP based on a single Downlink Control Information (DCI).

[0031] Figure 1C shows an example of a case where each of the multi-TRPs transmits a portion of the control signal to the UE, and the multi-TRP transmits the data signal (this may be called master-slave mode). Part 1 of the control signal (DCI) may be transmitted by TRP1, and part 2 of the control signal (DCI) may be transmitted by TRP2. Part 2 of the control signal may depend on part 1. The UE receives each PDSCH transmitted from the multi-TRP based on these parts of the DCI.

[0032] Figure 1D shows an example of a multi-TRP where each of the multi-TRPs transmits a separate control signal to the UE, and the multi-TRP transmits data signals (this may also be called multi-master mode). TRP1 may transmit a first control signal (DCI), and TRP2 may transmit a second control signal (DCI). The UE receives each PDSCH transmitted from the multi-TRP based on these DCIs.

[0033] When scheduling multiple PDSCHs from a multi-TRP (which may also be called multiple PDSCHs) as shown in Figure 1B using a single DCI, that DCI may be called a single DCI (S-DCI, single PDCCH). Similarly, when scheduling multiple PDSCHs from a multi-TRP (as shown in Figure 1D) using multiple DCIs, these multiple DCIs may be called multiple DCIs (M-DCI, multi-PDCCH (multiple PDCCH)).

[0034] Each TRP in a multi-TRP system may transmit different transport blocks (TBs), code words (CWs), and layers. Alternatively, each TRP in a multi-TRP system may transmit the same TB, CW, and layer.

[0035] Non-Coherent Joint Transmission (NCJT) is being considered as one form of multi-TRP transmission. In NCJT, for example, TRP1 modulates and layers a first codeword and transmits a first PDSCH using a first precode with a first number of layers (e.g., 2 layers). TRP2 modulates and layers a second codeword and transmits a second PDSCH using a second precode with a second number of layers (e.g., 2 layers).

[0036] Furthermore, 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. In other words, a first PDSCH from a first TRP and a second PDSCH from a second TRP may overlap in at least one of the time and frequency resources.

[0037] 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).

[0038] In URLLC for multiple TRPs, support for PDSCH (Transport Block (TB) or Codeword (CW)) repetition spanning multiple TRPs is being considered. Support for repetition schemes (URLLC schemes, e.g., schemes 1, 2a, 2b, 3, 4) spanning multiple TRPs on the frequency domain, layer (spatial) domain, or time domain is being considered. In scheme 1, multiple PDSCHs from multiple TRPs are performed using space division multiplexing (SDM). In schemes 2a and 2b, PDSCHs from multiple TRPs are performed using frequency division multiplexing (FDM). In scheme 2a, the redundant version (RV) is the same for multiple TRPs. In scheme 2b, the RV may be the same or different for multiple TRPs. In schemes 3 and 4, multiple PDSCHs from multiple TRPs are performed using time division multiplexing (TDM). In Scheme 3, multi-PDSCH signals from multi-TRPs are transmitted within a single slot. In Scheme 4, multi-PDSCH signals from multi-TRPs are transmitted within different slots.

[0039] Such multi-TRP scenarios allow for more flexible transmission control using high-quality channels.

[0040] NCJT using multiple TRPs / panels may utilize high ranks. To support ideal and non-ideal backhauls between multiple TRPs, both single DCI (single PDCCH, e.g., Figure 1B) and multi-DCI (multi-PDCCH, e.g., Figure 1D) may be supported. For both single and multi-DCI, the maximum number of TRPs may be 2.

[0041] An extension of the TCI is being considered for single PDCCH designs (primarily for ideal backhaul). Each TCI code point within the DCI may correspond to one or two TCI states. The TCI field size may be the same as that of Rel. 15.

[0042] For PDCCH / CORESET as defined in Rel.15, one TCI state without a CORESET Pool Index (CORESETPoolIndex) (also known as TRP Info) is set for one CORESET.

[0043] Regarding the PDCCH / CORESET enhancements specified in Rel.16, in multi-TRP based on multi-DCI, a CORESET pool index is set for each CORESET.

[0044] (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.

[0045] In inter-cell mobility (e.g., L1 / L2 inter-cell mobility), the UE may receive channels / signals from multiple cells / TRPs (see Figures 2A and 2B).

[0046] Figure 2A 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).

[0047] In this case, the port (e.g., antenna port) / TRP selection may be performed dynamically. The port (e.g., antenna port) / TRP selection may be based on the TCI state 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.

[0048] Figure 2B 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. Here, TRP#1 corresponds to physical cell ID (PCI)#1 and TRP#2 corresponds to PCI#2.

[0049] 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 2B. Here, we show the case where NCJT is performed between TPRs corresponding to different PCIs. Note that the same serving cell settings may be applied / configured for TRP#1 and TRP#2.

[0050] 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.

[0051] 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).

[0052] 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).

[0053] 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).

[0054] 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.”

[0055] In inter-cell mobility, either Scenario 1 or Scenario 2 is possible. In this disclosure, "serving cell" may be interpreted as "TRP within a serving cell." Layer 1 / layer 2 (L1 / L2) and DCI / Medium Access Control Control Element (MAC CE) may be interpreted as mutually interchangeable. In this disclosure, a PCI different from the Physical Cell Identity (PCI) of the current serving cell may simply be referred to as "different PCI." Non-serving cells, cells with different PCIs, candidate cells, and additional cells may be interpreted as mutually interchangeable.

[0056] <Scenario 1> Scenario 1 corresponds to, for example, inter-cell mobility in a multi-TRP. However, Scenario 1 may also be a scenario that does not correspond to inter-cell mobility in a multi-TRP. In Scenario 1, for example, the following steps are taken.

[0057] (1) The UE receives from the serving cell the settings for the SSB for beam measurement of the TRP corresponding to a PCI different from that of the serving cell, and the settings necessary to use wireless resources for data transmission and reception, including resources for a different PCI. (2) The UE performs beam measurements of the TRP corresponding to the different PCIs and reports the beam measurement results to the serving cell. (3) Based on the above report, the Transmission Configuration Indication (TCI) status associated with the TRP corresponding to the different PCI is activated by L1 / L2 signaling from the serving cell. (4) UEs send and receive data using dedicated channels on the TRP that correspond to different PCIs. (5) The UE must always cover the serving cell, including in the case of multi-TRP. The UE must use common channels from the serving cell (such as the Broadcast Control Channel (BCCH) and the Paging Channel (PCH)), as in conventional systems.

[0058] In Scenario 1, when the UE sends and receives signals with the additional cell / TRP (the TRP corresponding to the PCI of the additional cell), the serving cell (the UE's assumption of the serving cell) does not change. In other words, L1 / L2 switching of the serving cell is not supported. The UE sets higher-layer parameters related to the PCI of the non-serving cell from the serving cell. Scenario 1 may be applied, for example, in Rel. 17.

[0059] Figure 3A shows an example of UE movement in Rel.17. It assumes that the UE moves from a PCI#1 cell (serving cell) to a PCI#3 cell (additional cell) (overlapping with the serving cell). In this case, Rel.17 does not support L1 / L2 switching of serving cells.

[0060] An additional cell is a cell with an additional PCI that is different from the PCI of the serving cell. UEs can receive / transmit UE-specific channels from the additional cell. UEs need to be within the serving cell's coverage to receive UE-common channels (e.g., system information / paging / short messages). If a UE moves outside the serving cell's coverage, a cell switch is required, such as through a handover (also called L3 mobility).

[0061] <Scenario 2> In Scenario 2, L1 / L2 cell mobility is applied. With L1 / L2 cell mobility, serving cells can be changed using functions such as beam control without RRC reconfiguration. In other words, transmission and reception with additional cells are possible without handover (or without performing the L3 mobility procedure). Since handover requires RRC reconnection and other factors, resulting in a period of no data communication, applying L1 / L2 cell mobility, which does not require handover, allows data communication to continue even when the serving cell is changed. In Scenario 2, for example, the following procedure is performed.

[0062] (1) The UE receives the SSB settings for a cell with a different PCI (additional cell) from the serving cell for beam measurement / serving cell changes. (2) The UE performs beam measurements of the cell using different PCIs and reports the measurement results to the serving cell. (3) The UE may receive the configuration of cells with different PCIs (serving cell configuration) through upper-layer signaling (e.g., RRC). In other words, pre-configuration regarding serving cell changes may be performed. This configuration may be performed together with the configuration in (1) or separately. (4) Based on the above report, the TCI status of cells with different PCIs may be activated by L1 / L2 signaling in accordance with the change in the serving cell. The activation of the TCI status and the change in the serving cell may be performed separately. (5) The UE changes the serving cell (assumed to be the serving cell) and starts receiving / transmitting using the pre-configured individual UE channel and TCI state.

[0063] In other words, in Scenario 2, the serving cell (the assumed serving cell in the UE) is updated by L1 / L2 signaling. Scenario 2 may be applied in Rel. 18 and later.

[0064] Figure 3B shows an example of UE migration in Rel.18. In Rel.18, serving cells are switched via L1 / L2. UEs can receive / transmit UE-dedicated / common channels to and from the new serving cell. UEs may be outside the coverage of the previous serving cell.

[0065] (Setting candidate cells) In L1 / L2 inter-cell mobility, candidate cells may be set in addition to serving cells. In this disclosure, candidate cells may be read as target cells, additional cells, or additional PCIs. One or more candidate cells (or groups of candidate cells) may be associated separately with each serving cell, or one or more candidate cells (or groups of candidate cells) may be commonly associated with multiple serving cells.

[0066] The configuration of candidate cells (or candidate cell groups) may be set using predetermined higher-layer parameters (e.g., ServingCellConfig) in the same way as the inter-cell beam management (inter-cell BM) of existing systems (e.g., Rel.17 and earlier). Alternatively, the configuration of candidate cells (or candidate cell groups) may reuse the framework for carrier aggregation configuration (e.g., CA configuration framework) or the framework for CHO (Conditional Handover) / CPC (Conditional PSCell Change) configuration.

[0067] Candidate cells (or groups of candidate cells) defined by higher-level layer parameters may be activated / deactivated by MAC CE / DCI instructing the UE.

[0068] For setting candidate cells (or associating them with serving cells), at least one of the following setting examples 1 to 3 may be applied. Here, SpCell#0, SCell#1, and SCell#2 are set as serving cells, and an example of candidate cells / candidate cell groups set separately from the serving cells is shown. Setting examples 1 to 3 below are just examples, and the number of serving cells / candidate cells / candidate cell groups, the association between serving cells and candidate cells, 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.

[0069] [Example Configuration 1] Configuration Example 1 shows that one or more candidate cells are associated with / configured for each serving cell (or the frequency domain corresponding to each serving cell) (see Figure 4). Here, candidate cells #0-1, #0-2, and #0-3 are associated with SpCell#0 (or the frequency domain corresponding to SpCell#0), candidate cell #1-1 is associated with SCell#1 (or the frequency domain corresponding to SCell#1), and candidate cells #2-1 and #2-2 are associated with SCell#2 (or the frequency domain corresponding to SpCell#2). Information regarding these associations may be set / instructed by the base station to the UE via RRC / MAC CE / DCI.

[0070] [Example Configuration 2] Configuration Example 2 shows that candidate cells are associated with / configured for MAC entities / MCG / SCG (see Figure 4). This example shows the case where candidate cells #3-#8 are associated with MAC entities / MCG / SCG. In this case, candidate cells are configured for MAC entities or cell groups (e.g., MCG / SCG), rather than being associated with each individual 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.

[0071] [Example 3] In Configuration Example 3, one or more candidate cell groups are configured (see Figure 4). Each candidate cell group has one or more candidate cells. This example shows the configuration of candidate cell group #1 having candidate cells #0-#2, candidate cell group #2 having candidate cells #0 and #1, and candidate cell group #3 having candidate cell #0. At least one piece of information regarding the configured candidate cell groups and information regarding the candidate cells included in each candidate cell group may be set / instructed by the base station to the UE via RRC / MAC CE / DCI.

[0072] [Switching serving cells] Existing systems (e.g., Rel.17) support L1 beam indication for the TCI status of additional PCIs (or additional cells) (e.g., indication by the TCI status field of the DCI).

[0073] From Rel.18 onward, 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 switch). It is also 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.

[0074] For example, in candidate cell setting example 1, a predetermined candidate cell may be designated as a serving cell (or instructed to switch to a serving cell) via L1 / L2 signaling. Figure 5A 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.

[0075] 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 5B shows a case where candidate cell #4 becomes an MCG / SCG SpCell (SpCell #0 and candidate cell #4 are switched) via L1 / L2 signaling.

[0076] 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 5C 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. Among the candidate cells included in candidate cell group #1 (here, candidate cells #0-#2), a candidate cell associated with SpCell #0 or a candidate cell set in the same frequency domain as SpCell #0 (here, candidate cell #0) may be set as a new SpCell. Alternatively, the candidate cell that becomes an SpCell may be indicated by L1 / L2 signaling.

[0077] (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.

[0078] 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.).

[0079] 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).

[0080] 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.

[0081] 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.

[0082] TAGs (for example, serving cells belonging to the same TAG) may be defined by higher-level parameters. The same timing advance value may be applied to serving cells belonging to the same TAG. The timing advance group containing a 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).

[0083] 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 6). Figure 6 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).

[0084] 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.

[0085] A MAC CE for timing advance commands (TAC MAC CE) may be configured to include a field for the timing advance group index (e.g., TAG ID) and a field for the timing advance command (see Figure 7).

[0086] On the other hand, future wireless communication systems are expected to have cases where one or more TRPs corresponding to a given cell (or CC) are assigned different TAGs (or TAG-IDs). For example, in multi-TRP operations using multi-DCI, it is expected that two TAs (or TAGs) will be supported for UL transmission.

[0087] Alternatively, different TRPs corresponding to a given cell may share a common TAG. Furthermore, a MAC CE for TA commands may apply to only one TRP, or to multiple TRPs.

[0088] Alternatively, different TRPs (Traffic Rate Programs) may use different TAGs for different cells, or they may share a common TAG. For example, in intercell mobility, it is conceivable that UL transmissions could be controlled based on common / different timing advances for serving cells (or serving cell TRPs) and non-serving cells (or non-serving cell TRPs).

[0089] Thus, MIMO versions Rel.18 and later are expected to support two timing advances (TAs) for two TRPs in multi-TRP operation using multiple DCIs.

[0090] If TAGs are set / controlled on a TRP basis, a time alignment timer (e.g., timeAlignmentTimer) may be set for each TRP. The time alignment timer may control the time at which a MAC entity considers a serving cell belonging to an associated TAG to be uplink time aligned. For example, a time alignment timer may be set by the RRC to maintain UL time alignment.

[0091] A time alignment timer (e.g., timeAlignmentTimer) may be maintained for UL time alignment. In Rel.17, a time alignment timer (e.g., timeAlignmentTimer) corresponds to each 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 timer associated with the indicated timing advance group (e.g., TAG).

[0092] 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.

[0093] 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).

[0094] 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.

[0095] For example, if the time alignment timer expires, the following actions (e.g., a predetermined PTAG action / a predetermined STAG action) may be performed.

[0096] [Operation for specified PTAGs] If the time alignment timer is associated with the PTAG, • Flushes (discards) 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.

[0097] [Operation for specified STAG] If a time alignment timer is associated with a STAG, then for all serving cells belonging to that TAG, • Flushes (discards) 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.

[0098] 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 8A and 8B). Figure 8A shows an example of TAG (or TAG ID setting) per cell group in an existing system (e.g., Rel. 17 or earlier), and Figure 8B shows an example of setting a TAG ID for each candidate cell.

[0099] Furthermore, if candidate cells are configured / applied / supported, it is expected that different serving cells / different candidate cells will be associated with the same TAG, as shown in Figure 8B. 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.

[0100] 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).

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] (TA control per TRP / panel) As mentioned above, when using multiple transmission / reception points (e.g., TRPs) / panels for communication, it is also conceivable that timing advance (TA) may be controlled for each TRP / panel.

[0108] In NRs Rel.18 and later, for RACH triggered by PDCCH orders and RACH triggered by UEs, it is conceivable that contention-based random access (CBRA) and contention-free random access (CFRA) will be considered / determined on a TRP basis or a TRP TA (TA per TRP) basis.

[0109] If timing advances can be applied / configured for each TRP (or on a per-TRP basis), the UE controls UL transmissions (e.g., RACH transmissions, etc.) in each TRP based on the timing advance corresponding to each TRP (or the timing advance group to which each TRP belongs).

[0110] Information regarding the TRP corresponding to each serving cell (e.g., TRP index / TRP ID) may be set / instructed to the UE by the base station using RRC / MAC CE / downlink control information. The UE may also receive relevant information regarding the timing advance corresponding to each TRP (e.g., information regarding TA value / timing advance command / time alignment timer, etc.) from the base station.

[0111] Each embodiment of this disclosure may be applied to / supported in at least one of intra-cell multi-TRPs and inter-cell multi-TRPs.

[0112] In a multi-TRP within a cell, multiple TRPs (or the activated TCI states of multiple TRPs) may be associated with the same cell ID. The cell ID may be the physical cell ID (PCI).

[0113] In inter-cell multi-TRP, multiple TRPs (or the activated TCI states of multiple TRPs) may be associated with different cell IDs (e.g., PCIs). For example, in inter-cell multi-TRP, two TRPs may be interpreted as two TRPs each associated with two PCIs.

[0114] If the application / setting of timing advance is supported for each TRP (or per TRP), each TRP may belong to a different TAG. Multiple TRPs in a serving cell (e.g., two TRPs) may each belong to two TAGs. A TAG may contain multiple TRPs from multiple serving cells. All TRPs / serving cells within a TAG apply / maintain the same timing advance (TA) / same time alignment timer.

[0115] In this disclosure, a TAG may contain one or more sub-TAGs. For example, two TRPs of a serving cell may each belong to two sub-TAGs and also to one TAG. A sub-TAG may contain multiple TRPs from multiple serving cells. All TRPs / serving cells within a sub-TAG apply / maintain the same timing advance (TA) / same time alignment timer.

[0116] For example, a TA may be applied to each TRP (or instructions may be given on a TRP TA basis). For example, at least one of the following options may be applied.

[0117] [Option 1] A different TAG-ID may be set for each TRP, and a different MAC CE for TA commands may be set for each TRP. Each TAG may maintain a time alignment timer for UL time alignment.

[0118] [Option 2] Different TRPs may share a TAG. A MAC CE for a TA command may be applied to only one TRP. The UE applies different TAs to other TRPs. For example, the UE may adjust the TA value for other TRPs (e.g., TRP#1) by a TA offset (TA_TRP_offset) based on the TA for TRP#0 (TA_TRP#0).

[0119] In this case, only one time alignment timer may exist for the UL time alignment of multiple TRPs. This may mean that the UL time alignment of multiple TRPs may be maintained or lost simultaneously.

[0120] [Option 3] There may be only one TAG. The MAC CE for the TA command may be applied to multiple serving TRPs for the UE.

[0121] [Option 4] There may be only one TAG. MAC CEs for TA commands received on a TRP / CW / PDSCH / DMRS port group may be applied to the same TRP / CW / PDSCH / DMRS port group of the TAG. Each TRP / CW / PDSCH / DMRS port group of the TAG maintains a time alignment timer for UL time alignment.

[0122] Thus, in Rel.18 and later, it is anticipated that multiple timing advances will be supported in multi-TRP (e.g., multi-TRP using multi-DCI). For example, multiple (e.g., two) timing advances may be supported for multi-TRP using multi-DCI (e.g., two TRPs). Furthermore, the application of multiple timing advances to multi-TRP may be supported in intra-cell / inter-cell multi-DCI multi-TRP scenarios, or in multiple frequency ranges (e.g., FR1 and FR2).

[0123] (Association between TA and candidate cells) In TA (Terminal Adapter) for L1 / L2 cell-to-cell mobility, the association of TA / TAG (Tagnetic Aspect) to candidate cells is being considered in order to obtain the TA of a candidate cell before receiving a cell switching command (L1 / L2 signal (e.g., DCI / MAC CE)). Alt1:TA / TAG is implicitly associated with candidate cells. For example, an association between TA / TAG and TCI status may be set. Alt2: TA / TAG is explicitly associated with candidate cells. For example, TA / TAG may be associated with SSB(s) / TRS(s). This association may be provided as part of the candidate cell settings.

[0124] (UE transmission timing) The UE may have the ability to adapt to changes in the frame timing of the reference cell while connected. The UE's UL frame transmission may occur at a Timing Advance (TA) before the corresponding DL is received from the reference cell. Here, the TA is (NTA +N TA offset )xT C may be derived by. N TA is a predetermined value for TA, and N TA offset ) is an offset with respect to the predetermined value, and T C may be a reference time unit.

[0125] In the serving cell within PTAG, the UE uses the SpCell as the reference cell to derive the UE transmission timing for the cells within PTAG. On the other hand, in the serving cell within STAG, the UE uses any one of the plurality of activated SCell as the reference cell to derive the UE transmission timing for the cells within STAG. The accuracy of the UE's initial transmission timing and the requirements for stepwise timing adjustment may be defined by the specification.

[0126] In the present disclosure, the "reference cell" may mean the "reference cell" in "UL frame transmission is performed at a TA (Timing Advance) before the corresponding DL reception (the first detected path in time) from the reference cell". Also, the "reference TRP" may mean the "reference TRP" in "UL frame transmission is performed at a TA (Timing Advance) before the corresponding DL reception (the first detected path in time) from the reference TRP". That is, the cell and the TRP may be read interchangeably with each other.

[0127] Thus, the UE uses the reference cell / reference TRP to derive the UE transmission timing (i.e., TA) for the cell / TRP within the TAG.

[0128] (In-cell mobility) Starting with Rel.18, it is expected that setting a TA for each TRP will be supported for multi-DCI based multi-TRPs (e.g., mDCI MTRP). Multi-TRPs may support both intra-cell and inter-cell configurations. For example, for a multi-DCI based multi-TRP operation that supports multiple (e.g., two) TAs, setting two Timing Advance Groups (TAGs) belonging to the serving cell will be supported.

[0129] In L1 / L2 inter-cell mobility (for example, L1 / L2 inter-cell mobility), different TAGs may be set for serving cells / candidate cells.

[0130] In L1 / L2 intercell mobility, at least one of intracell multi-TRP (e.g., two TRPs sharing the same PCI) or intercell multi-TRP (e.g., two TRPs having different PCIs (similar to multi-DCI based multi-TRP in Rel. 17 / 18)) may be supported.

[0131] Information regarding the serving cell / candidate cell in which multi-TRP is configured may be set / instructed by the base station to the UE using higher-layer parameters / MAC CE / DCI, etc.

[0132] In the case of intracellular multi-TRP, the two TRPs corresponding to each cell may correspond to two TCI states associated with one PCI. In the case of intercellular multi-TRP, the two TRPs corresponding to different cells may correspond to two TCI states associated with two PCIs.

[0133] For L1 / L2 intercell mobility, the support / configuration of intra-cell and inter-cell multi-TRP, as well as the synchronous / asynchronous configuration, may be specified by the specifications.

[0134] (analysis) As mentioned above, with respect to inter-cell mobility, the existing specifications assume that the serving cell, SpCell / SCell, is used as the reference cell / reference TRP when deriving the TA for UE transmission. In other words, in existing UE operations, only serving cells are subject to TA derivation. On the other hand, future specifications are considering using non-serving cells / candidate cells, not just serving cells, as the reference cell. In other words, extending the existing UE operations related to TA derivation to non-serving cells / candidate cells is being considered.

[0135] However, it remains unclear whether non-serving cells can be used as reference cells. More specifically, it is necessary to clarify whether non-serving cells, unrelated to activated TCI states, can be used as reference cells in L1 / L2 inter-cell mobility.

[0136] Furthermore, in existing UE operation, as mentioned above, the UE uses the activated SCell as the reference cell within the STAG. However, in L1 / L2 cell mobility, there may be cases where no activated SCell exists within the STAG. For example, there may be cases where a serving cell exists but only deactive SCells exist, or where no serving cell exists but only non-serving cells exist as candidate cells. In other words, if there is no active SCell within the STAG, it is not clear which cell the UE will use as the reference cell.

[0137] Furthermore, regarding intra-cell / inter-cell multi-TRPs, for example, if two TRPs (two CORESETPoolIndexes) are set for a given cell, there may be cases where one of the TRPs is not currently associated with any active TCI state. In this case, it is unclear whether that TRP, which is not associated with any active TCI state, can be used as the base TRP for TA derivation.

[0138] Thus, in intra-cell / inter-cell mobility, if the reference cell / reference TRP for TA derivation is not clearly defined, the UE may not be able to properly control the TA, potentially leading to a deterioration in communication quality.

[0139] Therefore, the present inventors focused on the case of non-serving cells / candidate cells in relation to the application of reference cells for TA derivation, and conceived one aspect of this embodiment.

[0140] The embodiments of this disclosure will be described in detail below with reference to the drawings. Each wireless communication method according to the embodiments may be applied individually or in combination.

[0141] (Various substitutions, etc.) 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".

[0142] 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.

[0143] 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.

[0144] 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).

[0145] 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).

[0146] In this disclosure, physical layer signaling may include, for example, Downlink Control Information (DCI) and Uplink Control Information (UCI).

[0147] 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.

[0148] In this disclosure, terms such as index, identifier (ID), indicator, and resource ID may be interpreted interchangeably. In this disclosure, terms such as sequence, list, set, group, cluster, and subset may be interpreted interchangeably.

[0149] In this disclosure, the terms used include: panel, UE panel, panel group, beam, beam group, precoder, Uplink (UL) transmit entity, Transmission / Reception Point (TRP), base station, Spatial Relation Information (SRI), spatial relationship, SRS Resource Indicator (SRI), Control Resource Set (CORESET), Physical Downlink Shared Channel (PDSCH), Codeword (CW), Transport Block (TB), Reference Signal (RS), antenna port (e.g., Demodulation Reference Signal (DMRS) port), antenna port group (e.g., DMRS port group), group (e.g., spatial relationship group, Code Division Multiplexing (CDM) group, reference signal group, CORESET group, Physical Uplink Control Channel (PUCCH) groups, PUCCH resource groups, resources (e.g., reference signal resources, SRS resources), resource sets (e.g., reference signal resource sets), CORESET pools, downlink Transmission Configuration Indication state (TCI state) (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, quasi-co-location (QCL), QCL assumptions, etc., may be interpreted interchangeably.

[0150] 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" may be interpreted as mutually exclusive as "a set of spatial relationship information," "one or more spatial relationship information," etc. TCI state and TCI may be interpreted as mutually exclusive.

[0151] In this disclosure, TRP, CORESETPoolIndex, TRP ID, ID related to TRP, TAG ID, TCI status group, spatial relationship group, QCL source RS group, DL RS group, path loss RS group, and PCI (for inter-cell multi-TRP) may be interpreted as one another.

[0152] In this disclosure, being associated with different TRPs, being associated with different CORESET pool indexes (CORESETPoolIndex), being associated with different TRP IDs, being associated with different TRP IDs, being associated with different TAG IDs, being associated with different TCI state groups, being associated with different spatial relationship groups, being associated with different QCL source RS groups, being associated with different DL RS groups, being associated with different path loss RS groups, and being associated with different PCIs (for inter-cell multi-TRPs) may be interpreted as being associated with each other.

[0153] Each embodiment of this disclosure may be applied to at least one of intra-cell multi-TRP and inter-cell multi-TRP.

[0154] In this disclosure, intra-cell multi-TRP may mean that the activated TCI states of multiple (e.g., two) TRPs are associated with the same PCI.

[0155] In this disclosure, inter-cell multi-TRP may mean that the activated TCI states of multiple (e.g., two) TRPs are associated with different PCIs.

[0156] In this disclosure, in the case of inter-cell multi-TRPs, multiple (e.g., two) TRPs may mean multiple (e.g., two) TRPs associated with multiple (e.g., two) PCIs.

[0157] In this disclosure, non-serving cell, additional cell, candidate cell, and target cell may be interpreted as interchangeable.

[0158] In this disclosure, 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 in which a TA value is indicated / acquired. The reference cell may be defined in the specification or may be set / instructed by the base station to the UE via RRC / MAC CE / DCI.

[0159] In this disclosure, the term "reference TRP" may be interpreted as "reference TRP," "specific TRP," or "reference TRP."

[0160] In this disclosure, the cell switching command (L1 / L2 signal (e.g., DCI / MAC CE)), cell switching instruction information, and cell switching information may be interpreted interchangeably.

[0161] The following embodiments may apply when a RACH procedure is configured / supported for each TRP (or for each serving cell / additional cell / non-serving cell). Alternatively, the following embodiments may apply when a timing advance / timing advance group is configured / supported for each TRP (or for each serving cell / additional cell / non-serving cell).

[0162] 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 (e.g., intra-cell mobility (L1 / L2 intra-cell mobility)). L1 / L2 inter-cell mobility may be interpreted as at least one of cell switching, cell change, and cell modification.

[0163] (Wireless communication method) <First Embodiment> The first embodiment relates to the application of a reference cell for TA derivation in L1 / L2 inter-cell mobility.

[0164] In L1 / L2 inter-cell mobility, if STAG includes candidate cells that are non-serving cells, the UE may determine the reference cell for TA derivation based on at least one of the following options. Figures 9A-9C and 10A-10C show examples of the application of the reference cell according to the first embodiment.

[0165] <Option 1> The UE can use (apply) a non-serving cell as the reference cell in STAG, whether or not the non-serving cell is associated with an activated TCI state (which may also be called an active TCI state) (see Figure 9A).

[0166] <Option 2> The UE cannot use a non-serving cell as the reference cell in STAG, regardless of whether the non-serving cell is associated with an activated TCI state or not (see Figure 9B). In this case, the UE can use an activated SCell as the reference cell in STAG (see Figure 9B).

[0167] <Option 3> If no other activated SCells exist within the STAG, the UE can use a non-serving cell as the base cell in the STAG, regardless of whether or not it is associated with an activated TCI state (see Figure 9C).

[0168] <Option 4> The UE can use a non-serving cell as the reference cell in STAG if the non-serving cell is associated with an activated TCI state (see Figure 10A).

[0169] <Option 4-1> The UE cannot use a non-serving cell as the reference cell in STAG if the non-serving cell is not associated with any activated TCI state (see Figure 10B). In this case, the UE can use an activated SCell as the reference cell in STAG (see Figure 10B).

[0170] <Option 4-2> The UE can use a non-serving cell as the base cell in the STAG if the non-serving cell is not associated with any activated TCI state and there are no other activated SCells in the STAG (see Figure 10C).

[0171] According to the first embodiment described above, the UE can appropriately determine the reference cell for TA derivation in L1 / L2 inter-cell mobility.

[0172] <Second Embodiment> A second embodiment relates to the application of a reference cell for TA derivation in the case of intracellular multi-TRP.

[0173] [Embodiment 2-1] Embodiment 2-1 describes a case in which the PTAG includes the TRP of the SpCell. The UE may determine the reference cell for TA derivation based on at least one of the following options. Figures 11A-11C show an example of the application of the reference cell according to the second embodiment (Embodiment 2-1).

[0174] <Option 1> The UE can use the SpCell / TRP#0 as the reference cell / reference TRP in the PTAG, even if the PTAG contains the SpCell's TRP#0 and that TRP#0 is not associated with any activated TCI state (see Figure 11A).

[0175] <Option 2> If the PTAG contains SpCell's TRP#0 and that TRP#0 is associated with an activated TCI state, the UE can use that SpCell / that TRP#0 as the reference cell / reference TRP in the PTAG.

[0176] <Option 2-1> If the PTAG contains SpCell's TRP#0 and TRP#0 is not associated with any activated TCI state, the UE cannot use that SpCell / TRP#0 as the reference cell / reference TRP in the PTAG (see Figure 11B). In this case, the UE can use an activated SCell (e.g., SCell#1) as the reference cell (see Figure 11B). Alternatively, the UE can use a TRP associated with an activated TCI state in an activated SCell as the reference TRP.

[0177] <Option 2-2> The UE can use the SpCell / TRP#0 as the reference cell / reference TRP in the PTAG if the PTAG contains the SpCell's TRP#0, and that TRP#0 is not associated with any activated TCI state, and there are no other activated SCells / TRPs associated with activated TCI states in the PTAG (only if so) (see Figure 11C).

[0178] [Embodiment 2-2] Embodiment 2-2 specifically describes the case where the STAG includes the SCell's TRP. The UE may determine the reference cell for TA derivation based on at least one of the following options. Figures 12A-12C show examples of the application of the reference cell according to the second embodiment (Embodiment 2-2).

[0179] <Option 1> UE can use SCell#1 / TRP#0 as the reference cell / reference TRP in STAG, even if STAG contains SCell#1TRP#0 and TRP#0 is not associated with any activated TCI state (see Figure 12A).

[0180] <Option 2> If STAG contains SCell#1 and TRP#0, and TRP#0 is associated with an activated TCI state, then UE can use SCell#1 / TRP#0 as the reference cell / reference TRP in STAG.

[0181] <Option 2-1> If the STAG contains SCell#1 with TRP#0, and TRP#0 is not associated with any activated TCI state, the UE cannot use SCell#1 / TRP#0 as the reference cell / reference TRP in the STAG (see Figure 12B). In this case, the UE can use an activated SCell (e.g., SCell#2) as the reference cell (see Figure 12B). Alternatively, the UE can use a TRP associated with an activated TCI state in an activated SCell as the reference TRP.

[0182] <Option 2-2> The UE can use SCell#1 / TRP#0 as the reference cell / reference TRP in the STAG if the STAG contains SCell#1 / TRP#0, and TRP#0 is not associated with any activated TCI state, and there are no other activated SCells / TRPs associated with activated TCI states in the STAG (only in this case) (see Figure 12C).

[0183] According to the second embodiment described above, the UE can appropriately determine the reference cell for TA derivation in the case of multiple TRPs within a cell.

[0184] <Third Embodiment> A third embodiment relates to the application of a reference cell for TA derivation in the case of inter-cell multi-TRP.

[0185] [Embodiment 3-1] Embodiment 3-1 describes a case in which the PTAG includes the TRP of the SpCell. The UE may determine the reference cell for TA derivation based on at least one of the following options. Figures 13A-13B show an example of the application of the reference cell according to the third embodiment (Embodiment 3-1).

[0186] <Option 1> The UE can apply each of the options in Embodiment 2-1 described above if the TRP is associated with the PCI of the serving cell.

[0187] <Option 2> The UE can apply each of the options in Embodiment 2-1 described above if the TRP is associated with a PCI of a non-serving cell. Alternatively, the UE can apply the following options 3-4.

[0188] <Option 3> If TRP#0 is associated with a PCI of a non-serving cell, the UE cannot use that SpCell / TRP#0 as the reference cell / reference TRP in the PTAG, regardless of whether or not that TRP#0 is associated with an activated TCI state (see Figure 13A). In this case, the UE can use an activated SCell (e.g., SCell#1) as the reference cell (see Figure 13A). Alternatively, the UE can use a TRP associated with an activated TCI state in an activated SCell as the reference TRP.

[0189] <Option 4> If TRP#0 is associated with a PCI of a non-serving cell, the UE may use that SpCell / TRP#0 as the reference cell / reference TRP in the PTAG, regardless of whether TRP#0 is associated with an activated TCI state or not, only if there are no other activated SCells / TRPs associated with activated TCI states in the PTAG (see Figure 13B).

[0190] [Embodiment 3-2] Embodiment 3-2 specifically describes the case where the STAG includes the SCell's TRP. The UE may determine the reference cell for TA derivation based on at least one of the following options. Figures 14A-14B show examples of the application of the reference cell according to the third embodiment (Embodiment 3-2).

[0191] <Option 1> The UE can apply each of the options in Embodiment 2-2 described above if the TRP is associated with the PCI of the serving cell.

[0192] <Option 2> The UE may apply each of the options in Embodiment 2-2 described above if the TRP is associated with a PCI of a non-serving cell. Alternatively, the UE may apply the following options 3-4.

[0193] <Option 3> If SCell#1's TRP#0 is associated with a PCI of a non-serving cell, the UE cannot use SCell#1 / TRP#0 as the reference cell / reference TRP in STAG, regardless of whether TRP#0 is associated with an activated TCI state or not (see Figure 14A). In this case, the UE can use an activated SCell (e.g., SCell#2) as the reference cell (see Figure 14A). Alternatively, the UE can use a TRP associated with an activated TCI state in an activated SCell as the reference TRP.

[0194] <Option 4> If SCell#1's TRP#0 is associated with a non-serving cell PCI, the UE can use SCell#1 / TRP#0 as the reference cell / reference TRP in the STAG, regardless of whether TRP#0 is associated with an activated TCI state or not, only if there are no other activated SCells / no TRPs associated with activated TCI states in the STAG (see Figure 14B).

[0195] According to the third embodiment described above, the UE can appropriately determine the reference cell for TA derivation in the case of inter-cell multi-TRP.

[0196] <Fourth Embodiment> A fourth embodiment relates to the extension of the reference cell for TA derivation in L1 / L2 inter-cell mobility and intra-cell / inter-cell multi-TRP mobility.

[0197] [Embodiment 4-1] In serving cells, non-serving cells, and candidate cells within a PTAG, the UE may use a SpCell as a reference cell to derive the UE transmission timing (TA) for cells within the PTAG. Similarly, in serving cells, non-serving cells, and candidate cells within a STAG, the UE may use any of the activated SCells as a reference cell to derive the UE transmission timing (TA) for cells within the STAG. The accuracy of the UE's initial transmission timing and the requirements for stepwise timing adjustments may be defined by the specification.

[0198] [Embodiment 4-2] If no activated SCell exists within STAG, UE may determine the reference cell for TA derivation based on at least one of the following options:

[0199] <Option 1> The UE can use a deactive SCell, which has been set as a candidate cell for L1 / L2 inter-cell mobility, as a reference cell.

[0200] <Option 2> The UE can use non-serving cells that have been set as candidate cells for L1 / L2 inter-cell mobility as reference cells.

[0201] <Option 3> If DL synchronization / UL synchronization is performed with a deactivated SCell / non-serving cell in Option 1 / Option 2, the UE can use that cell as a reference cell.

[0202] <Option 4> If there is an active TCI state associated with a deactive SCell / non-serving cell in Option 1 / Option 2, the UE can use that cell as a reference cell.

[0203] <Option 5> If the UE performs CSI / L1-RSRP / L1-SINR measurements on a deactive SCell / non-serving cell in Option 1 / Option 2, that cell can be used as a reference cell.

[0204] <Option 6> If the UE triggers a RACH procedure on a deactive SCell / non-serving cell in Option 1 / Option 2, or receives a PDCCH order that triggers a RACH procedure, it can use that cell as a reference cell.

[0205] <Option 7> Each serving cell / non-serving cell / candidate cell may send a UL frame at a Timing Advance (TA) prior to the corresponding DL reception (the first detected path in time) from the reference cell. This may mean that one cell does not refer to the DL frame of another cell.

[0206] <Variations> Priorities may be defined for the cell types described in options 1-7 above (active / deactive SCells, non-serving cells, cells with / without DL synchronization / UL synchronization, cells with / without active TCI state, cells with / without measurement, cells with / without RACH trigger, etc.). For example, if there are no high-priority cells in STAG, UE may use a low-priority cell as the reference cell in STAG.

[0207] [Embodiment 4-3] If no cells within the TAG are activated and no TRPs within the TAG are associated with an activated TCI state, the UE is not required to maintain a TA for UL transmission in the TAG.

[0208] According to the fourth embodiment described above, the UE can appropriately determine the reference cell for TA derivation in L1 / L2 inter-cell mobility and intra-cell / inter-cell multi-TRP mobility.

[0209] <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.

[0210] 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.

[0211] 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.

[0212] Furthermore, the notification of any information to the UE in the above-described embodiment may be periodic, semi-persistent, or aperiodic.

[0213] [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.

[0214] 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.

[0215] If the above notice is issued by the UCI, the notice may be sent using PUCCH or PUSCH.

[0216] Furthermore, the notification of any information from the UE in the above-described embodiments may be periodic, semi-persistent, or aperiodic.

[0217] [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.

[0218] At least one of the embodiments described above may apply only to a UE that has reported or supports a particular UE capability.

[0219] The specific UE capability may represent at least one of the following: • To support specific processing / operation / control / information for at least one of the above embodiments. • To support mobility within L1 / L2 cells and mobility between L1 / L2 cells. • Support for TA (Technical Action) per TRP in intra-cell / inter-cell multi-TRP (Track Relay Program) scenarios. • Support for configuring intra-cell multi-TRP / inter-cell multi-TRP for serving cells / non-serving cells. • Support for changing the frame timing of the reference cell.

[0220] 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).

[0221] 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)).

[0222] 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 configure / activate specific information related to the embodiments described above (or to perform the actions of the embodiments described above). For example, such specific information may be information indicating the activation of random access procedures / PRACH transmissions without RAR monitoring, or arbitrary RRC parameters for a particular release (e.g., Rel. 18 / 19).

[0223] 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.

[0224] (Note) With regard to one embodiment of this disclosure (the first embodiment), the following invention is added. [Note 1] A receiving unit that receives cell switching instruction information in inter-cell mobility, The system includes a control unit that determines the timing advance (TA) to be applied to UL transmission based on the cell switching instruction information, The control unit is a terminal that determines a reference cell for deriving the timing advance group (TAG) based on whether or not a candidate cell is included in the TAG. [Note 2] The terminal as described in Appendix 1, wherein the control unit applies the candidate cell as the reference cell in the TAG if the TAG includes the candidate cell. [Note 3] The terminal as described in Appendix 1 or Appendix 2, wherein the control unit applies an activated secondary cell (SCell) within the TAG, or the candidate cell, as the reference cell when the candidate cell is not associated with an active Transmit Setting Instruction (TCI) state. [Note 4] The terminal according to any one of the appendices 1 to 3, wherein the control unit applies the candidate cell as the reference cell in the TAG if the TAG includes the candidate cell, the candidate cell is not associated with an active transmit setting instruction (TCI) state, and there are no activated secondary cells (SCells) in the TAG.

[0225] (Note) With regard to one embodiment of this disclosure (the second and third embodiments), the following inventions are added. [Note 1] A receiving unit that receives cell switching instruction information in intra-cell or inter-cell mobility that supports multiple transmit / receive points (TRPs), The system includes a control unit that determines the timing advance (TA) to be applied to UL transmission based on the cell switching instruction information, The control unit is a terminal that determines a reference cell or reference TRP for deriving the TA based on whether or not the TRP of a specific cell is included in the Timing Advance Group (TAG). [Note 2] The terminal as described in Appendix 1, wherein the control unit applies the specific cell as the reference cell in the TAG, or applies the TRP as the reference TRP in the TAG, when the TAG includes the TRP of the specific cell. [Note 3] The terminal as described in Appendix 1 or Appendix 2, wherein the control unit applies an activated secondary cell (SCell) within the TAG as the reference cell, or applies another TRP associated with an activated TCI state in the SCell as the reference TRP, if the TRP is not associated with an active transmit setting instruction (TCI) state. [Note 4] The terminal according to any one of the appendices 1 to 3, wherein the control unit applies the specific cell as the reference cell in the TAG, or applies the TRP as the reference TRP in the TAG, if the TAG includes the TRP of the specific cell, the TRP is not associated with an active transmit setting instruction (TCI) state, and there are no activated secondary cells (SCells) in the TAG.

[0226] (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.

[0227] Figure 15 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).

[0228] 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.

[0229] 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.

[0230] 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))).

[0231] 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.

[0232] The user terminal 20 may be connected to at least one of the plurality of base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) and dual connectivity (DC) using a plurality of component carriers (CCs).

[0233] Each CC may be included in at least one of the first frequency range (Frequency Range 1 (FR1)) and the second frequency range (Frequency Range 2 (FR2)). The macro cell C1 may be included in FR1, and the small cell C2 may be included in FR2. For example, FR1 may be a frequency band of 6 GHz or less (sub-6 GHz), and FR2 may be a frequency band higher than 24 GHz (above-24 GHz). Note that the frequency bands, definitions, etc. of FR1 and FR2 are not limited to these, and for example, FR1 may correspond to a frequency band higher than FR2.

[0234] Also, the user terminal 20 may communicate using at least one of time division duplex (TDD) and frequency division duplex (FDD) in each CC.

[0235] The plurality of base stations 10 may be connected by wire (e.g., an optical fiber compliant with Common Public Radio Interface (CPRI), an X2 interface, etc.) or wirelessly (e.g., NR communication). For example, when NR communication is used as a backhaul between base stations 11 and 12, the base station 11 corresponding to the upper-level station may be called an Integrated Access Backhaul (IAB) donor, and the base station 12 corresponding to the relay station (relay) may be called an IAB node.

[0236] The base station 10 may be connected to the core network 30 via another base station 10 or directly. The core network 30 may include, for example, at least one of Evolved Packet Core (EPC), 5G Core Network (5GCN), Next Generation Core (NGC), etc.

[0237] The core network 30 may include network functions (NFs) such as, for example, 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), Operation, Administration and Maintenance (Management) (OAM). Note that a single network node may provide multiple functions. Also, communication with an external network (e.g., the Internet) may be performed via the DN.

[0238] The user terminal 20 may be a terminal corresponding to at least one of communication systems such as LTE, LTE-A, 5G, etc.

[0239] 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).

[0240] 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.

[0241] 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.

[0242] 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.

[0243] 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.

[0244] 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.

[0245] 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.

[0246] 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.

[0247] 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.

[0248] 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.

[0249] In this disclosure, downlinks, uplinks, etc., may be expressed without the prefix "link." Also, the prefix "physical" may be omitted from the names of various channels.

[0250] 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.

[0251] 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.

[0252] 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).

[0253] (base station) Figure 16 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.

[0254] 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.

[0255] The control unit 110 controls the entire base station 10. The control unit 110 can consist of a controller, control circuit, etc., as described based on common understanding in the art relating to this disclosure.

[0256] 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.

[0257] 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.

[0258] The transmission / reception unit 120 may be configured as an integrated transmission / reception unit, or may be composed of a transmission unit and a reception unit. The transmission unit may be composed of a transmission processing unit 1211 and an RF unit 122. The reception unit may be composed of a reception processing unit 1212, an RF unit 122, and a measurement unit 123.

[0259] The transmission / reception antenna 130 can be composed of an antenna described based on the common knowledge in the technical field related to the present disclosure, such as an array antenna.

[0260] The transmission / reception unit 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transmission / reception unit 120 may receive the above-mentioned uplink channel, uplink reference signal, etc.

[0261] The transmission / reception unit 120 may form at least one of a transmission beam and a reception beam by using digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc.

[0262] The transmission / reception unit 120 (transmission processing unit 1211) may perform processing of the Packet Data Convergence Protocol (PDCP) layer, processing of the Radio Link Control (RLC) layer (e.g., RLC retransmission control), processing of the Medium Access Control (MAC) layer (e.g., HARQ retransmission control), etc. on, for example, data and control information obtained from the control unit 110, and generate a bit sequence to be transmitted.

[0263] 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.

[0264] 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.

[0265] 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.

[0266] 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.

[0267] 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.

[0268] 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.

[0269] 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.

[0270] The transmitting / receiving unit 120 may transmit cell switching instruction information in inter-cell mobility. The transmitting / receiving unit 120 may receive a UL signal transmitted from a terminal by applying a timing advance (TA) determined based on the cell switching instruction information. The determination of whether a reference cell for deriving the TA is included in a timing advance group (TAG) may be based on whether or not a candidate cell is included.

[0271] The transmitting / receiving unit 120 may transmit cell switching instruction information in intra-cell or inter-cell mobility that supports multiple transmission / receiving points (TRPs). The transmitting / receiving unit 120 may receive UL signals transmitted from a terminal by applying a timing advance (TA) determined based on the cell switching instruction information. The reference cell or reference TRP for deriving the TA may be determined based on whether or not the TRP of a particular cell is included in the timing advance group (TAG).

[0272] (User terminal) Figure 17 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.

[0273] 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.

[0274] 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.

[0275] 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.

[0276] 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.

[0277] 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.

[0278] 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.

[0279] 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.

[0280] 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.

[0281] 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.

[0282] 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.

[0283] 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.

[0284] 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.

[0285] 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.

[0286] 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.

[0287] 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.

[0288] 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.

[0289] 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.

[0290] The transmitting / receiving unit 220 may receive cell switching instruction information in inter-cell mobility. The transmitting / receiving unit 220 may transmit a random access channel (PRACH) based on a first PDCCH order. The MAC CE may include at least one of a field relating to cell switching and a field relating to the TA. The MAC CE may include at least one of a field relating to TA adjustment and an absolute TA command (TAC). The MAC CE may include another field indicating the presence of a field relating to TA instruction.

[0291] The control unit 210 may determine a timing advance (TA) to apply to UL transmission based on the cell switching instruction information. The control unit 210 may determine a reference cell for deriving the TA based on whether or not a candidate cell is included in the timing advance group (TAG). If the candidate cell is included in the TAG, the control unit 210 may apply the candidate cell as the reference cell in the TAG. If the candidate cell is not associated with an active transmit setting instruction (TCI) state, the control unit 210 may apply an activated secondary cell (SCell) in the TAG, or the candidate cell, as the reference cell. If the TAG is included in the candidate cell, the candidate cell is not associated with an active transmit setting instruction (TCI) state, and there are no activated secondary cells (SCells) in the TAG, the control unit 210 may apply the candidate cell as the reference cell in the TAG.

[0292] The transmitting / receiving unit 220 may receive cell switching instruction information in intra-cell or inter-cell mobility that supports multiple transmission / receiving points (TRPs).

[0293] The control unit 210 may determine a timing advance (TA) to apply to UL transmission based on the cell switching instruction information. If the TAG includes the TRP of the specific cell, the control unit 210 may apply the specific cell as the reference cell in the TAG, or apply the TRP as the reference TRP in the TAG. If the TRP is not associated with an active transmit setting instruction (TCI) state, the control unit 210 may apply an activated secondary cell (SCell) in the TAG as the reference cell, or apply the TRP to another TRP associated with an activated TCI state in the SCell as the reference TRP. The control unit 210 may, if the TAG includes the TRP of the specific cell, the TRP is not associated with an active transmit setting instruction (TCI) state, and there are no activated secondary cells (SCells) within the TAG, apply the specific cell as the reference cell in the TAG, or apply the TRP as the reference TRP in the TAG.

[0294] (Hardware configuration) The block diagrams used in the description of the above embodiments show functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may also be realized by combining the above one device or the above multiple devices with software.

[0295] Here, functions include, but are not limited to, judgment, decision, determination, calculation, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission may be called a transmitting unit or transmitter. In all cases, as mentioned above, the method of implementation is not particularly limited.

[0296] For example, a base station, user terminal, etc. in one embodiment of the present disclosure may function as a computer that processes the wireless communication method of the present disclosure. Figure 18 is a diagram showing an example of the hardware configuration of a base station and user terminal according to one embodiment. The base station 10 and user terminal 20 described above may be physically configured as a computer device including a processor 1001, memory 1002, storage 1003, communication device 1004, input device 1005, output device 1006, bus 1007, etc.

[0297] In this disclosure, terms such as apparatus, circuit, device, section, and unit are interchangeable. The hardware configuration of the base station 10 and the user terminal 20 may include one or more of the devices shown in the figure, or it may be configured without some of the devices.

[0298] For example, although only one processor 1001 is shown in the diagram, there may be multiple processors. Furthermore, processing may be performed by one processor, or by two or more processors simultaneously, sequentially, or by other means. Note that processor 1001 may be implemented using one or more chips.

[0299] Each function in the base station 10 and the user terminal 20 is realized, for example, by loading predetermined software (programs) onto hardware such as the processor 1001 and memory 1002, which allows the processor 1001 to perform calculations and control communication via the communication device 1004, or to control at least one of the reading and writing of data in the memory 1002 and storage 1003.

[0300] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may be composed of a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, etc. For example, at least a part of the control unit 110 (210) and the transmitting / receiving unit 120 (220) described above may be implemented by the processor 1001.

[0301] 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.

[0302] 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.

[0303] 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.

[0304] 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).

[0305] 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).

[0306] 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.

[0307] 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.

[0308] (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.

[0309] 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.

[0310] 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.

[0311] 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.

[0312] 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.

[0313] 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.

[0314] 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.

[0315] 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.

[0316] 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.

[0317] Furthermore, if one slot or one mini-slot is referred to as TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit of scheduling. In addition, the number of slots (number of mini-slots) that constitute the minimum time unit of scheduling may be controlled.

[0318] A TTI with a time length of 1 ms may also be called a normal TTI (TTI in 3GPP Rel.8-12), a long TTI, a normal subframe, a long subframe, or a slot. A TTI shorter than a normal TTI may also be called a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini slot, a sub slot, or a slot.

[0319] Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more.

[0320] A Resource Block (RB) is a resource allocation unit in the time domain and frequency domain, and in the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers in an RB may be the same regardless of the neurology, for example, 12. The number of subcarriers in an RB may be determined based on the neurology.

[0321] Furthermore, an RB may contain one or more symbols in the time domain and may have the length of one slot, one minislot, one subframe, or one TTI. Each TTI, subframe, etc., may consist of one or more resource blocks.

[0322] One or more RBs may also be called Physical RBs (PRBs), Sub-Carrier Groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB pairs, etc.

[0323] 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.

[0324] 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.

[0325] 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.

[0326] 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".

[0327] 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.

[0328] 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.

[0329] 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.

[0330] 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.

[0331] 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.

[0332] 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.

[0333] 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).

[0334] 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).

[0335] 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 providing notification of the specified information or by providing notification of other information).

[0336] 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).

[0337] 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.

[0338] 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.

[0339] 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).

[0340] 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.

[0341] 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.

[0342] 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.

[0343] 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.

[0344] 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.

[0345] 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.

[0346] 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.

[0347] 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.

[0348] 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.

[0349] A base station can accommodate one or more (e.g., three) cells. If a base station accommodates multiple cells, the entire coverage area of ​​the base station can be divided into multiple 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.

[0350] 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.

[0351] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0352] 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.

[0353] 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.

[0354] 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.

[0355] 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.

[0356] Figure 19 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.

[0357] 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.

[0358] 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).

[0359] 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.

[0360] 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.

[0361] 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.).

[0362] 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.

[0363] 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.

[0364] 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).

[0365] 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.

[0366] 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).

[0367] 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.

[0368] 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.

[0369] 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.

[0370] 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.

[0371] 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.

[0372] 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).

[0373] 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."

[0374] Any reference to elements using designations such as “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, 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.

[0375] 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.

[0376] 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).

[0377] 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.

[0378] 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…”

[0379] 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).

[0380] The term "maximum transmit power" as used in this disclosure may mean the maximum transmit power, the nominal UE maximum transmit power, or the rated UE maximum transmit power.

[0381] 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.”

[0382] 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).

[0383] 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."

[0384] 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.

[0385] 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.

[0386] 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").

[0387] In this disclosure, "of," "for," "regarding," "related to," and "associated with" may be interpreted as being interchangeable.

[0388] 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.

[0389] 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.

[0390] 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 receiving unit that receives cell switching instruction information in intra-cell or inter-cell mobility that supports multiple transmit / receive points (TRPs), The system includes a control unit that determines the timing advance (TA) to be applied to UL transmission based on the cell switching instruction information, The control unit is a terminal that determines a reference cell or reference TRP for deriving the TA based on whether or not the TRP of a specific cell is included in the Timing Advance Group (TAG).

2. The terminal according to claim 1, wherein the control unit applies the specific cell as the reference cell in the TAG, or applies the TRP as the reference TRP in the TAG, if the TAG includes the TRP of the specific cell.

3. The terminal according to claim 1, wherein the control unit applies an activated secondary cell (SCell) within the TAG as the reference cell if the TRP is not associated with an active transmit configuration instruction (TCI) state, or applies another TRP associated with an activated TCI state in the SCell as the reference TRP.

4. The terminal according to claim 1, wherein the control unit applies the specific cell as the reference cell in the TAG, or applies the TRP as the reference TRP in the TAG, if the TRP is not associated with an active transmit configuration instruction (TCI) state and there are no activated secondary cells (SCell) in the TAG.

5. The steps include receiving cell switching instruction information in intra-cell or inter-cell mobility that supports multiple transmit / receive points (TRPs), The steps include determining the timing advance (TA) to be applied to UL transmission based on the cell switching instruction information, A wireless communication method for a terminal, comprising the step of determining a reference cell or reference TRP for deriving the TA based on whether or not the TRP of a specific cell is included in the Timing Advance Group (TAG).

6. A transmitting unit that transmits cell switching instruction information in intra-cell or inter-cell mobility that supports multiple transmit / receive points (TRPs), The system includes a receiving unit that receives a UL signal transmitted from a terminal by applying a timing advance (TA) determined based on the cell switching instruction information, A base station in which the reference cell or reference TRP for deriving the aforementioned TA is determined based on whether or not the TRP of a specific cell is included in the Timing Advance Group (TAG).

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