Terminal, wireless communication method, and base station

Abstract

A terminal according to one embodiment of the present disclosure is characterized by being provided with: a receiving unit that receives a Medium Access Control Control Element (MAC CE) related to cell handover; and a control unit that determines, on the basis of information included in the MAC CE, a timing advance (TA) to be applied to UL transmission, the MAC CE including at least one of a field related to cell handover and a field related to the TA. According to one embodiment of the present disclosure, communication can be appropriately controlled even when inter-cell mobility is performed.

Description

Technical Field

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

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

[0003] The development of successor systems to LTE is also underway (e.g., also known as the 5th generation mobile communication system (5G), 5G+ (plus), the 6th generation mobile communication system (6G), New Radio (NR), 3GPP Rel.15 and later, etc.).

[0004] Existing technical documents

[0005] Non-patent literature

[0006] Non-patent document 1: 3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Envisioning future wireless communication systems (e.g., Rel.16 / 5G and beyond) where communication is controlled based on inter-cell mobility including non-serving cells, or by inter-cell mobility utilizing multiple transmit / receive points (e.g., Multi-TRP (MTRP)). Within inter-cell mobility, it is also envisioned that candidate cells are designated independently of the serving cell, and that handover / switching between the serving cell and candidate cells is performed.

[0009] However, when applying inter-cell mobility (e.g., handover between serving and candidate cells), how to control UL transmission (e.g., timing advance control) becomes a problem. For example, it is envisioned that supporting random access procedures without a Random Access Response (RAR) could be used as a method for obtaining timing advance. Furthermore, methods for obtaining timing advance include UE-based TA measurement and SRS-based TA measurement.

[0010] On the other hand, it is unclear how the base station should instruct the TA (Temporal Response) to the UE. Without proper advance indication of timing, inter-cell mobility cannot be adequately achieved, raising concerns about degraded communication quality.

[0011] This disclosure is made in view of the points involved, and one of its objectives is to provide terminals, wireless communication methods and base stations that can be appropriately controlled even when conducting inter-cell mobility.

[0012] Methods for solving problems

[0013] The terminal according to one aspect of this disclosure is characterized by having: a receiving unit for receiving a Medium Access Control Element (MAC CE) related to cell handover; and a control unit for determining a timing advance (TA) to be applied to UL transmission based on information contained in the MAC CE, wherein the MAC CE contains at least one of a field related to cell handover and a field related to the TA.

[0014] The effects of the invention

[0015] According to one aspect of this disclosure, communication can be appropriately controlled even when inter-cell mobility is being performed. Attached Figure Description

[0016] Figure 1A This is a diagram illustrating an example of UE movement in Rel.17. Figure 1BThis is a diagram illustrating an example of UE movement in Rel.18.

[0017] Figure 2 This is a diagram illustrating an example of the association between serving cells and candidate cells.

[0018] Figure 3A This is a diagram representing the second example of option 2 for candidate cell settings. Figure 3B This is a diagram representing the third example of option 2 for candidate cell settings.

[0019] Figure 4 This is a diagram illustrating example 1 of a serving cell handover.

[0020] Figure 5 This is a diagram representing Example 2 of serving cell handover.

[0021] Figure 6 This is a diagram representing example 3 of a serving cell handover.

[0022] Figure 7 This is a diagram representing an example of a timing advance group (TAG) to which a cell belongs within a cell group.

[0023] Figure 8 This is a diagram illustrating an example of a MAC CE used to execute timed advance commands.

[0024] Figure 9 This is another example of a MAC CE used to represent a timed advance command.

[0025] Figure 10 This diagram illustrates an example of TAG settings when TAG IDs are associated with candidate cells.

[0026] Figure 11 This is a diagram that represents an overview of L1L2-triggered mobility (LTM).

[0027] Figure 12 It is a diagram representing a RACH (PDCCH ordered RACH) based on PDCCH indications used for serving cells, with random access response (RAR) monitoring.

[0028] Figure 13 It is a diagram representing a RACH (PDCCH ordered RACH) based on PDCCH indications used for candidate cells without Random Access Response (RAR) monitoring.

[0029] Figure 14 This is a diagram illustrating an example of the MAC CE according to the first embodiment.

[0030] Figure 15 This is a diagram illustrating an example of the MAC CE according to the first embodiment.

[0031] Figure 16 This is a diagram illustrating an example of the MAC CE according to the first embodiment.

[0032] Figure 17 This is a diagram illustrating an example of the MAC CE according to the first embodiment.

[0033] Figures 18A-18C This is a diagram showing a variation of the MAC CE according to the first embodiment.

[0034] Figures 19A-19C This is a diagram showing a variation of the MAC CE according to the first embodiment.

[0035] Figure 20 This is a diagram illustrating an example of the schematic structure of a wireless communication system according to one embodiment.

[0036] Figure 21 This is a diagram illustrating an example of the structure of a base station according to one embodiment.

[0037] Figure 22 This is a diagram illustrating an example of the structure of a user terminal according to one embodiment.

[0038] Figure 23 This is a diagram illustrating an example of the hardware structure of a base station and a user terminal according to one embodiment.

[0039] Figure 24 This is a diagram illustrating an example of a vehicle according to one embodiment. Detailed Implementation

[0040] (TCI, Spatial Relations, QCL)

[0041] In NR, research is being conducted on the reception processing (e.g., at least one of receiving, demapping, demodulation, and decoding) and transmission processing (e.g., at least one of transmitting, mapping, precoding, modulation, and encoding) of at least one of control signals and channels (referred to as signal / channel) in the UE based on the Transmission Configuration Indication state (TCI state).

[0042] TCI states can also represent the TCI states of signals / channels applied to the downlink. The equivalent TCI states of signals / channels applied to the uplink can also be described as spatial relations.

[0043] The so-called TCI status is information related to the quasi-co-location (QCL) of a signal / channel, and can also be referred to as spatial reception parameters, spatial relation information, etc. The TCI status can also be set for the UE on a per-channel or per-signal basis.

[0044] QCL is an indicator of the statistical properties of a signal / channel. For example, it can also mean that when a signal / channel has a QCL relationship with other signals / channels, it can be assumed that at least one of the following is the same among these different signals / channels: Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (e.g., spatial Rx parameter) (with regard to at least one of them being the QCL).

[0045] Additionally, the spatial reception parameters may also correspond to the UE's receive beam (e.g., receive analog beam), and the beam may also be determined based on the spatial QCL. The QCL (or at least one element of the QCL) in this disclosure may also be rewritten as sQCL (spatial QCL).

[0046] A QCL can also be defined with multiple types (QCL types). For example, four QCL types, or types AD, can be set, where the parameters (or parameter sets) that can be assumed to be the same are different. These parameters (also called QCL parameters) are represented as follows:

[0047] • QCL Type A (QCL-A): Doppler shift, Doppler spread, average delay, and delay spread.

[0048] • QCL Type B (QCL-B): Doppler shift and Doppler extension,

[0049] • QCL Type C (QCL-C): Doppler shift and average delay,

[0050] • QCL Type D (QCL-D): Spatial reception parameters.

[0051] The assumption that a UE envisions a relationship between a Control Resource Set (CORESET), channel, or reference signal and other CORESETs, channels, or reference signals in a specific QCL (e.g., QCL type D) is called a QCL assumption.

[0052] The UE may also determine at least one of the transmit beam (Tx beam) and receive beam (Rx beam) of the signal / channel based on the TCI state or QCL assumption of the signal / channel.

[0053] The TCI state can also be, for example, information related to the QCL between the target channel (in other words, the reference signal (RS) used by the channel) and other signals (e.g., other RSs). The TCI state can also be set (indicated) by higher-layer signaling, physical-layer signaling, or a combination thereof.

[0054] In addition, the channel / signal that becomes the application object in the TCI state can also be called the target channel / reference signal (target channel / RS), or simply the target, etc. The other signals mentioned above can also be called reference RS, source RS, or simply reference, etc.

[0055] The channel that is set (specified) to TCI state or spatial relationship can be, for example, at least one of the following: downlink shared channel (Physical Downlink Shared Channel (PDSCH))), downlink control channel (Physical Downlink Control Channel (PDCCH))), uplink shared channel (Physical Uplink Shared Channel (PUSCH))), and uplink control channel (Physical Uplink Control Channel (PUCCH))).

[0056] Furthermore, the RS that is related to the channel as QCL can be at least one of the following: a Synchronization Signal Block (SSB), a Channel State Information Reference Signal (CSI-RS), a Measurement Reference Signal (Sounding Reference Signal (SRS)), a Tracking CSI-RS (also known as a Tracking Reference Signal (TRS)), a QCL Detection Reference Signal (also known as a QRS), or a DeModulation Reference Signal (DMRS).

[0057] An SSB is a block of signals that includes at least one Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a broadcast channel (Physical Broadcast Channel (PBCH)). An SSB can also be referred to as an SS / PBCH block.

[0058] The RS of QCL type X in TCI state can also refer to the RS that is in a relationship of QCL type X with a certain channel / signal (DMRS), and the RS can also be called the QCL source of QCL type X in TCI state.

[0059] (L1 / L2 inter-cell mobility)

[0060] As described above, the study investigates UL transmission of a UE to one or more cells / TRPs. As a procedure in this case, consider scenario 1 or scenario 2 below. Additionally, in this disclosure, the serving cell can also be rewritten as the TRP within the serving cell. Layer 1 / Layer 2 (L1 / L2) and the DCI / Medium Access Control Element (MAC CE) can also be rewritten. In this disclosure, a PCI that differs from the physical cell ID (Physical Cell Identity (PCI)) of the current serving cell is sometimes abbreviated as "different PCI". Non-serving cells, cells with different PCIs, and additional cells can also be rewritten.

[0061] <Scenario 1>

[0062] Scenario 1 could be a scenario that corresponds to inter-cell mobility in multi-TRP, but it could also be a scenario that does not correspond to inter-cell mobility in multi-TRP.

[0063] (1) UE receives from the serving cell: the setting of the SSB for beam measurement of the TRP corresponding to a different PCI from the serving cell, and the settings required for using radio resources for data transmission and reception, including resources of different PCIs.

[0064] (2) The UE performs beam measurement for the TRP corresponding to different PCIs and reports the beam measurement results to the serving cell.

[0065] (3) Based on the above report, the Transmission Configuration Indication (TCI) status associated with the TRP corresponding to different PCIs is activated by L1 / L2 signaling from the serving cell.

[0066] (4) The UE uses the dedicated channel on the TRP corresponding to different PCIs for transmission and reception.

[0067] (5) The UE needs to always cover the serving cell, including in the case of multiple TRPs. Similar to previous systems, the UE needs to use common channels from the serving cell (Broadcast Control Channel (BCCH), Paging Channel (PCH)), etc.

[0068] In Scenario 1, when the UE transmits and receives signals with the additional cell / TRP (the TRP corresponding to the PCI of the additional cell), the serving cell (the assumption of the serving cell in the UE) is not changed. The UE can also have higher-layer parameters associated with the PCI of a non-serving cell set from the serving cell. Scenario 1 can also be applied in Rel. 17, for example.

[0069] Figure 1A This diagram illustrates an example of UE movement in Rel.17. Suppose the UE moves from a cell with PCI#1 (serving cell) to a cell with PCI#3 (additional cell) (overlapping with the serving cell). In this case, in Rel.17, the serving cell will not be handed over via L1 / L2. An additional cell is a cell with an additional PCI different from the serving cell. The UE can receive / transmit UE-dedicated channels from the additional cell. For the UE to receive UE-common channels (e.g., system information / paging / SMS), it needs to be within the coverage area of ​​the serving cell.

[0070] <Scenario 2>

[0071] In Scenario 2, L1 / L2 inter-cell mobility is applied. With L1 / L2 inter-cell mobility, serving cell changes can be performed using functions such as beam control without RRC resetting. In other words, transmission and reception with the additional cell can be performed without handover. Since periods of data communication disruption occur due to the need for RRC reconnection for handover, data communication can continue even during serving cell changes by applying L1 / L2 inter-cell mobility that does not require handover. Scenario 2 can also be applied, for example, in Rel. 18. In Scenario 2, for example, the following process is performed.

[0072] (1) In order to change the beam measurement / serving cell, the UE receives the SSB settings of the cell (additional cell) with different PCI from the serving cell.

[0073] (2) The UE performs beam measurements for cells using different PCIs and reports the measurement results to the serving cell.

[0074] (3) The UE can also receive the settings (serving cell settings) of cells with different PCIs through higher-layer signaling (e.g., RRC). That is, it can also make advance settings related to serving cell changes. This setting can be made together with the setting in (1) or separately.

[0075] (4) Based on the above report, the TCI status of cells with different PCIs can also be activated via L1 / L2 signaling according to the change of the serving cell. The activation of the TCI status and the change of the serving cell can also be carried out separately.

[0076] (5) The UE changes its serving cell (the concept of the serving cell) and uses a pre-set UE-specific channel and TCI state to start receiving / transmitting.

[0077] In other words, in Scenario 2, the serving cell (the intended serving cell in the UE) is updated via L1 / L2 signaling. Scenario 2 can also be applied in Rel.18.

[0078] Figure 1B This diagram illustrates an example of UE movement in Rel.18. In Rel.18, the serving cell is handed over via L1 / L2. The UE can receive / transmit UE-dedicated channels / common channels between the new serving cell and the new serving cell. The UE can also leave the coverage area of ​​its previous serving cell.

[0079] (Setting up multiple candidate cells)

[0080] Figure 2This diagram illustrates an example of the association between a serving cell and candidate cells. Let SpCell#0, SCell#1, or SCell#2 be the serving cell. SpCell refers to a special cell (including the primary cell (PCell) and the primary / secondary cell (PSCell)). SCell refers to the secondary cell. SpCell#0 is associated with candidate cells #0-1, #0-2, and #0-3. SCell#1 is associated with candidate cell #1-1. SCell#2 is associated with candidate cells #2-1 and #2-2. Thus, a serving cell can also be associated with more than one candidate cell (candidate serving cell).

[0081] Regarding the setting of candidate cells (candidate cells) in the case of becoming a changed serving cell, consider options 1 and 2 as follows.

[0082] <Option 1>

[0083] As with inter-cell mobility in Rel.17, the information in ServingCellConfig can also include information related to multiple candidate cells. In this case, multiple candidate cells need to share the same PDCCH / PDSCH / UL settings as the serving cell.

[0084] For example, in Rel.17 inter-cell mobility, "mimoParam-r17" is appended under ServingCellConfig, adding PCI configuration information. mimoParam-r17 may also contain additionalPCI-ToAddModList-r17, which is a list of additional SSBs with PCIs different from the serving cell's PCI. In candidate cells (additional cells, cells with additional PCIs), some information may be applied, but the same settings as the serving cell may also be used.

[0085] <Option 2>

[0086] Multiple candidate cells can also be assigned complete settings corresponding to each cell (e.g., ServingCellConfig), or the carrier aggregation (CA) configuration framework can be reused to associate them with each serving cell. That is, candidate cells can also be assigned different settings instead of sharing configuration information with the serving cell. Because the UE is provided with complete settings for each candidate cell, it is able to communicate appropriately with the candidate cells.

[0087] Within the CA (Cell Controller) configuration framework, SpCells can be configured for each cell group, and multiple SCells can be added. Alternatively, by reusing the CA framework, serving cells can be configured for each cell group based on L1 / L2 inter-cell mobility, and multiple candidate cells can be configured. Candidate cells can also be activated / deactivated via MAC CE (Machine-Assisted Cell Execution). Alternatively, the TCI (Tracking Control Information) information corresponding to the candidate cells can be activated / deactivated via MAC CE, thereby activating / deactivating the candidate cells. This method is considered beneficial for reducing the complexity of UE (User Equipment) operations.

[0088] Figure 3A This is a diagram representing the first example of option 2 for candidate cell settings. Figure 3A In the example, the common candidate cell pool used for cell handover in the MCG / SCG is applied to the candidate cells. That is, the candidate cells are treated as a pool (group) regardless of the frequency band.

[0089] Figure 3B This is a diagram representing the second example of option 2 for candidate cell settings. Figure 3B In this example, multiple cell groups are configured, enabling cell group handover via L1 / L2 signaling. Candidate cells are configured for each cell group, and the configuration for each group includes the indexes of the corresponding SpCell and SCell.

[0090] (Signaling used for service cell change instructions)

[0091] This section describes the implicit or explicit signaling used for serving cell change indications.

[0092] [Method 1]

[0093] In Method 1, the implicit signaling used for service cell change indication is described.

[0094] [[Option 1-1]]

[0095] When a specific Control Resource Set (CORESET) (e.g., at least one of CORESET#0, CH5Type0-CSS, or CH6 / CH7 / CH8 CSS) and more than one TCI state associated with a cell with a PCI different from the serving cell's PCI are indicated (activated) via MAC CE (for a specific CORESET, the case where more than one TCI state associated with a cell with a PCI different from the serving cell's PCI is indicated / activated via MAC CE), the UE can also determine to change the serving cell to another cell (cell x, a cell with a different PCI). That is, this activation can also implicitly indicate changing the serving cell to another cell.

[0096] In this case, the UE can also update the beam of other CORESET IDs, other CORESETs using CH6 / CH7 / CH8, or other CORESETs using CSS to the same TCI state as the activated TCI state mentioned above.

[0097] [[Options 1-2]]

[0098] When MAC CE activates / deactivates the TCI state of PDSCH, if all the TCI states activated by MAC CE are associated with the same cell x that has a PCI different from the serving cell's PCI, the UE can also determine that the serving cell has been changed to another cell (cell x). That is, this association can also implicitly indicate that the serving cell has been changed to another cell.

[0099] When this option is applied, if the NW (base station) does not change the serving cell, the MAC CE needs to include the TCI state associated with other cells (e.g., the current serving cell or a cell with a second different PCI) when activating the TCI state of the PDSCH associated with a cell with a different PCI.

[0100] [[Options 1-3]]

[0101] MAC CE activates / deactivates unified TCI states (e.g., corresponding to the unified TCI framework in Rel.17). When all activated unified TCI states are associated with the same cell x with different PCIs, the UE can also determine that the serving cell has been changed to another cell (cell x). That is, this association can also implicitly indicate that the serving cell has been changed to another cell.

[0102] [Method 2]

[0103] In Method 2, the explicit signaling used for serving cell change indication is described. Method 2 is applied, for example, in Scenario 2 described above.

[0104] [[Option 2-1]]

[0105] The following is an example of a serving cell change instruction. Additionally, the activation / deactivation of non-serving cells, changes to the serving cell, and sending / receiving data with other cells (non-serving cells) that have a physical cell ID different from the serving cell's physical cell ID can also be mutually modified.

[0106] The UE may also receive a new MAC CE for activating / deactivating a non-serving cell, containing at least one of the fields (1) to (3) below corresponding to the non-serving cell. Upon receiving this MAC CE, the UE may also determine that the serving cell has been changed to another cell (non-serving cell). Furthermore, the UE may control the transmission and reception of DL / UL signals with the non-serving cell based on this information. In addition, there may be one or more non-serving cells. In the example shown below, a MAC CE containing multiple fields representing multiple non-serving cell indices is applied.

[0107] (1) Service cell ID.

[0108] (2) BWP ID.

[0109] (3) The non-serving cell ID used for activation. The non-serving cell ID can also be replaced with any information corresponding to the non-serving cell (that can identify the non-serving cell).

[0110] As an example of (3), any of (3-1) to (3-5) can also be applied.

[0111] (3-1) PCI (PCI that is used directly). For example, 10 bits are used.

[0112] (3-2) Re-indexing of non-serving cells (new ID). The new ID can also be associated with a portion of the PCI and is set only for the serving and non-serving cells used by the UE. The new ID reduces the number of bits compared to the PCI.

[0113] (3-3) CSI report setting ID (CSI-ReportConfigId) (the case where CSI-ReportConfig corresponds to one or more non-serving cells).

[0114] (3-4) CSI Resource Configuration ID (CSI-ResourceConfigId) (CSI-ResourceConfigId corresponds to one or more non-serving cells).

[0115] (3-5) shows the bitmap for the activation / deactivation of each non-serving cell. The size (number of bits) of the bitmap can also be the same as the number of non-serving cells set on the CC. For example, in the case of activating the second non-serving cell out of 3 non-serving cells, it is set to "010".

[0116] At least one of the information contained in the MAC CE can also be included in the DCI. Alternatively, at least one of the serving cells activated via the MAC CE can also be indicated via the DCI. The MAC CE / DCI can also include a field indicating the TCI status / SSB / CSI-RS from a cell with a different PCI, so that the UE can identify the monitored DL beam on the target cell (the changed serving cell). The UE can also use the TCI status / SSB / CSI-RS to generate and send a beam report (CSI report).

[0117] [[Option 2-2]]

[0118] The UE can also receive a MAC CE with a new 1-bit field "C" appended to the existing MAC CE. This field indicates whether a change of serving cell is being performed. The UE can also receive this MAC CE and determine whether to change the serving cell to another cell based on this field.

[0119] [[Options 2-3]]

[0120] For MAC CE in option 2-2, the fields representing the serving cell index / PCI / other ID (such as the new ID in option 2-1 above) and the TCI status / SSB / CSI-RS of the target cell (the changed serving cell) can also be included in MAC CE.

[0121] In this way, the indication for serving cell change is indicated via MAC CE / DCI, so the UE can make appropriate changes to the serving cell.

[0122] [Serving Cell Handover Example 1]

[0123] Figure 4This diagram illustrates Example 1 of serving cell handover. For example, in the serving cell SpCell#0 of the MCG / SCG, if it is instructed via L1 / L2 signaling to change the serving cell to candidate cell #0-2, then candidate cell #0-2 becomes the new serving cell SpCell#0. Similarly, for example, in the serving cell SCell#2 of the MCG / SCG, if it is instructed via L1 / L2 signaling to change the serving cell to candidate cell #2-1, then candidate cell #2-1 becomes the new serving cell SCell#2.

[0124] [Serving Cell Handover Example 2]

[0125] The RRC / MAC CE can set global candidate cell IDs (cell#0, ..., 5) for each cell group, each band, each FR, and each UE. The UE can also be instructed to hand over the serving cell using this global candidate cell ID.

[0126] Figure 5 This is a diagram illustrating example 2 of serving cell handover. (Compared to...) Figure 3A Similarly, by setting up a pool of multiple candidate cells, the serving cell can be switched to any (activated) candidate cell within the pool via L1 / L2 signaling. In this case, the set candidate cell can become either a SpCell or an SCell based on L1 / L2 signaling.

[0127] The UE can also receive indications of changes to the serving cell (from cell #2-1 to candidate cell 4) via MAC CE / DCI. Furthermore, the indicated candidate cell #4 becomes the SpCell of the new cell group.

[0128] [Serving Cell Handover Example 3]

[0129] The RRC / MAC CE can set global candidate cell IDs (cell#0-1, #0-1, ..., 2-2) for each cell group, each frequency band, each FR, and each UE. The UE can also be instructed to hand over the serving cell through this global candidate cell ID.

[0130] Figure 6 This diagram illustrates Example 3 of serving cell handover. The UE receives an indication of a change in serving cell (from cell #2-0 to cell #2-1) via MAC CE / DCI. The indicated cell #2-1 becomes the SpCell of the new cell group. Furthermore, cells in the same cell group as the indicated cell #2-1 (cell #0-0, cell #1-0) become Scell ​​#1 and Scell ​​#2, respectively. In other words, the serving cell group is switched.

[0131] (Pre-scheduled group)

[0132] When using multiple TRPs, situations arise where the distance between the UE and each TRP differs. Multiple TRPs can also be contained within the same cell (e.g., a serving cell). Alternatively, one of the multiple TRPs can be equivalent to the serving cell, while the others can be equivalent to non-serving cells. In this case, it is also assumed that the distance between each TRP and the UE will differ.

[0133] In existing systems, the transmission timing of UL (Uplink) channels and / or UL signals (UL channels / signals) is adjusted through Timing Advance (TA). The reception timing of UL channels / signals from different User Terminals (UEs) is adjusted at the radio base station (also known as the Transmission and Reception Point (TRP), gNB, etc.).

[0134] The UE can also apply timing advance (multiple timing advance) according to each pre-set Timing Advance Group (TAG) to perform timing control of UL transmission.

[0135] In applications with multiple timing advances, Timing Advance Groups (TAGs) categorized by transmission timing are supported. The UE envisions applying the same TA offset (or TA value) to each TAG to control the UL transmission timing within each TAG. That is, the TA offset can also be set independently for each TAG.

[0136] When multiple timing advances are applied, the UE can independently adjust the transmission timing of the cell belonging to each TAG, so that the uplink signal reception timing from the UE can be aligned in the radio base station even when multiple cells are used.

[0137] TAGs (e.g., serving cells belonging to the same TAG) can also be set via higher-layer parameters. The same timing advance value can also be applied to serving cells belonging to the same TAG (e.g., serving cells with a set UL). Alternatively, the timing advance group of the SpCell containing the MAC entity can be called the primary timing advance group (PTAG), and other TAGs can be called secondary timing advance groups (STAG). Furthermore, the maximum number of TAGs can also be X per cell group (e.g., MCG / SCG) (e.g., X=4).

[0138] In existing systems (e.g., Rel.16 NR), a maximum of 4 tags are supported per cell group (e.g., MCG / SCG) (see reference). Figure 7 ).exist Figure 7 The text indicates that for a cell group containing SpCell and SCell#1~#4, three tags are set. Here, the following situation is shown: SpCell and SCell#1 belong to the first tag (PTAG or TAG#0), SCell#2 and SCell#3 belong to the second tag (TAG#1), and SCell#4 belongs to the third tag (TAG#2).

[0139] Timing advance command (TA command) can also be notified to the UE via MAC control elements (e.g., MAC CE). A TA command is a command representing the transmission timing value of the uplink channel and is contained within the MAC control element. The TA command (TAC) is signaled from the radio base station to the UE at the MAC layer. The UE controls specific timers (e.g., TA timers) based on the receipt of the TA command.

[0140] The MAC CE used for the advance timing command can also be a structure that includes fields for the advance timing group index (e.g., TAG ID) and fields for the advance timing command (see reference). Figure 8 The MAC CE can also be composed of an octet (=8 bits).

[0141] The TAG ID field can also consist of 2 bits, for example. The TAG ID field can also be used to indicate the TAG ID of a TAG that has been assigned an address. The Timing Advance Command field can also consist of 6 bits, for example. The TAC field can also represent the index value T of the amount / value (relative amount / relative value) of timing adjustments that must be applied to the MAC entity for control. A (0, 1, 2...63). Figure 8 The MAC CE used for the timing advance command shown can also be called TAC MACCE.

[0142] Figure 9 This is a diagram illustrating other examples of MAC CE used for timed advance commands. Figure 9 The MAC CE shown can also be called an absolute TAC MAC CE. A MAC CE can also consist of two octets (=16 bits). Specifically, the MAC CE can also include a field for reserved bits (R bit field) and a field for timing advance commands (TAC field). The R bit field (R=0) can, for example, consist of 4 bits. The TAC field can also span two octets, for example, consisting of 12 bits. Figure 8Similarly, Figure 9 The TAC field can also represent the index value of the actual TA (absolute quantity / absolute value) that must be applied to control the MAC entity. Furthermore, the absolute TAC MAC CE may not contain this value. Figure 8 The TAG ID field shown.

[0143] Figure 8 The MAC CE shown can also be used after the initial access has been established. Alternatively, it can also be... Figure 9 The MAC CE shown is used only during initial access and is included in RAR, etc. The fields included in the MAC CE used for the aforementioned timing advance command can also be referred to as TA-related fields. Figure 8 The TAC field shown can also be called the TA adjustment field / field used to indicate TA adjustment / field related to TA adjustment. Figure 9 The TAC field shown can also be called an absolute TAC field / a field used to indicate an absolute TAC.

[0144] Parameters corresponding to each TAG ID can also be set via higher-level parameters. For example, parameters such as the time alignment timer (e.g., timeAlignmentTimer) corresponding to each TAG ID can also be set. Alternatively, for each serving cell, the TAG ID can also be set via higher-level parameters (e.g., the tag-ID contained in ServingCellConfig). Furthermore, after being set via higher-level parameters, the TAG ID / parameters can be updated via MAC CE.

[0145] The time alignment timer can also be maintained for UL time alignment. In Rel.17, the time alignment timer is set / associated per TAG. When the UE receives a MAC CE (e.g., TAC MAC CE) for a timing advance command, it starts or restarts the time alignment timer associated with the indicated timing advance group (e.g., TAG).

[0146] The MAC entity receives TAC MAC CE and maintains a specific value (N) between itself and the indicated TAG. TA In the case of ), the application advances the timing command for the indicated TAG, or starts or restarts the time-aligned timer associated with the indicated TAG. Specific value (N) TA It can also be a timed advance between DL and UL.

[0147] Operations when the time alignment timer expires can also be defined separately in PTAG and STAG. Alternatively, the timing advance group (TAG) of the SpCell containing the MAC entity can be called the primary timing advance group (PTAG), and other TAGs can be called secondary timing advance groups (STAG).

[0148] For example, in Rel.17, it is also possible to support: applying a specific PTAG operation when the timer corresponding to PTAG expires, and applying a specific STAG operation when the timer corresponding to STAG expires.

[0149] For example, the following operations can also be performed when the time alignment timer expires (e.g., specific PTAG operation / specific STAG operation).

[0150] [Specific PTAG operations]

[0151] When the time alignment timer is associated with the PTAG

[0152] • Flush all HARQ buffers for all serving cells.

[0153] • If configured, notify the RRC to release the PUCCH to all serving cells.

[0154] • If configured, notify the RRC to release the SRS.

[0155] • Clear all set DL assignments and set UL assignments.

[0156] • Clear the PUSCH resource used for semi-persistent CSI reporting.

[0157] • Make all running time alignment timers expire.

[0158] • Maintain N for all tags TA .

[0159] [Specific STAG operations]

[0160] When a time alignment timer is associated with a STAG, for all serving cells belonging to that TAG,

[0161] • Refresh all HARQ buffers.

[0162] • If configured, notify the RRC to release the PUCCH.

[0163] • If configured, notify the RRC to release the SRS.

[0164] • Clear all assigned DL and UL values.

[0165] • Clear the PUSCH resource used for semi-persistent CSI reporting.

[0166] • Maintain the N of this TAG TA .

[0167] (Control based on UL transmission in advance at a set time)

[0168] In future wireless communication systems, it is envisioned that, in inter-cell mobility, UL transmission will be controlled based on timing advance for both the serving cell (or the serving cell's TRP) and non-serving / additional cells (or the non-serving / additional cell's TRP). Alternatively, it is envisioned that in future wireless communication systems, different TAGs (or TAG-IDs) will be assigned to more than one TRP corresponding to a cell (or CC) (e.g., multiple TRPs with different PCIs). Furthermore, it is envisioned that different TRPs corresponding to a cell will share a common TAG.

[0169] Figure 10 This is a diagram illustrating an example of TAG settings for different cells (or TRPs) within a PCI.

[0170] It is also envisioned that each CC can be configured with a maximum of M PCIs (e.g., serving cell + candidate cells associated with the serving cell), and for the maximum of M PCIs, a maximum of N (e.g., N≤M) TAGs can be configured. In this case, one or more PCIs can also be associated with a TAG.

[0171] Alternatively, within a cell group of up to S serving cells (or, for a maximum of S serving cells), one or more PCIs can be associated with a single TAG. In this case, a maximum of T TAGs can be assigned based on one PCI per CC (Case 1). That is, a maximum of T×N TAGs can also be assigned to a maximum of M×S cells. Or, a maximum of U TAGs can also be assigned to a maximum of M×S cells (Case 2).

[0172] Thus, when candidate cells are set / applied / supported, different serving cells / different candidate cells are envisioned to be associated with the same TAG. The TAG of a candidate cell can be indicated by the base station or determined by the UE based on the obtained candidate cell TAG.

[0173] Furthermore, for UL transmission of candidate cells (e.g., candidate cells with handover to serving cell indication), the UE considers the TA corresponding to the candidate cell when performing UL transmission. When considering the TA of the candidate cell, the UE generates the need to acquire the TA of the candidate cell (e.g., TA acquisition of candidate cells).

[0174] For candidate cell TA acquisition, several TA acquisition methods are considered, including TA acquisition utilizing RACH (e.g., RACH-based solutions) and TA acquisition not utilizing RACH (RACH-less solutions). The TA acquisition method can also be rewritten with respect to the TA acquisition scheme, TA acquisition type, or TA acquisition process. In this disclosure, the acquisition of TA, the measurement of TA, the calculation of TA, the determination of TA, and the decision of TA can also be rewritten interchangeably.

[0175] For example, a UE can also send a RACH (e.g., a PDCCH orderered RACH) to a candidate cell, which is indicated / triggered via the PDCCH, thereby obtaining the candidate cell's TA. Information related to the candidate cell's TA (e.g., the TA value) can also be included in the RACH's response signal (e.g., a RAR). The RAR can be sent from either the serving cell or the candidate cell. Alternatively, the candidate cell's TA can be obtained using a UE-triggered RACH or a RACH triggered by the network via higher layers. The PDCCH command can also be triggered only by the source cell (or, the serving cell).

[0176] Alternatively, the UE can also send signals other than RACH to the candidate cell to obtain the TA of the candidate cell. Information related to the TA of the candidate cell (e.g., TA value) can also be indicated to the UE from the base station. As a signal other than RACH, SRS (SRS-based TA measurement) can also be applied, for example.

[0177] Alternatively, the UE may measure / calculate / obtain the TA for a candidate cell based on DL signals (e.g., downlink reference signals) transmitted from each cell (e.g., candidate cell / serving cell). The method by which the UE obtains the TA for a candidate cell based on DL signals transmitted from more than one cell can also be referred to as UE-based TA measurement (e.g., UE-based TA measurement).

[0178] In UE-based TA measurements, the downlink reference signal can also be a specific DL signal (e.g., a synchronization signal block (e.g., SSB) / CSI-RS, etc.). For example, the UE can also measure the timing difference / difference of the received DL signals from multiple cells (or two cells) to obtain the TA of a candidate cell.

[0179] A reference cell (e.g., the serving cell) may also be included among multiple cells. In this case, the UE may also 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.

[0180] (An overview of L1L2-triggered mobility (LTM))

[0181] Figure 11 This is a diagram illustrating the general overview of L1L2-triggered mobility (LTM). LTM and L1 / L2 inter-cell mobility can also be rewritten interchangeably. During UE reconfiguration, the UE receives candidate cell configurations from the NW. UE reconfiguration includes T... RRC T proccesing1 / Tproccesing2 T RRC (For example, a maximum of 10ms) is the processing time for RRC reconfiguration (RRC reconfiguration) to carry candidate cell settings (candidate configurations). proccesing1 / Tproccesing2 (For example, the maximum usage time for the same FR is 20ms, and the maximum usage time for different FRs is 40ms) represents the time used for UE processing before and after the cell handover command. This includes situations such as L2 / 3 reconfiguration, RF retuning, baseband retuning, and security updates if necessary.

[0182] DL synchronization includes T search T Δ T margin T search(For example, 0ms when the cell is known, and a maximum of 60ms when the cell is unknown) is the time required to search for the target cell. Δ This is the time used for fine-grained tracking and acquisition of all timing information. T margin (For example, a maximum of 2ms) is the time used for post-processing of SSB and CSI-RS.

[0183] L1 measurement includes T meas (SMTC cycle (e.g., 20ms)). T meas It is the measurement delay from the appearance of the target to the cell handover command.

[0184] UL synchronization includes T IU T RAR T cmd T IU (For example, a maximum of 15ms) is the indeterminate interruption time when an initial PRACH opportunity (occasion) is obtained in a new cell. T RAR (For example, a maximum of 4ms) is the RAR latency. T cmd (For example, a maximum of 5ms) is the processing time for L1 / L2 commands (HARQ and paging).

[0185] T cmd The T after that first-data It is the time when the UE performs its initial DL reception / UL transmission on the indicator beam of the target cell after RAR.

[0186] Figure 12 This is a diagram representing a RACH (PDCCH ordered RACH) based on PDCCH instructions used for serving cells, with Random Access Response (RAR) monitoring. Additionally, in this disclosure, source cell and source cell group can be interchanged. Furthermore, candidate cell and candidate cell group can also be interchanged.

[0187] The source cell sends candidate cell settings to the UE. Then, the source cell sends a RACH indication (PDCCH order) based on PDCCH (e.g., including DCI format 1_0) to the UE. Additionally, a candidate cell is indicated in this indication because parallel RAR is more complex. Then, for TAG / TA acquisition, the UE sends the PRACH during the RACH process to the candidate cell.

[0188] Next, the source cell sends a RAR (TA Instruction) to the UE. In this case, since only one Common Search Space (CSS) is set, the RAR is monitored on the SpCell (only within the Distributed Unit (DU)). Furthermore, the UE can also transmit and receive within its current serving cell. Then, TA adjustment is performed in the source cell.

[0189] Next, the source cell sends a cell handover command to the UE. At this point, the TA information can be moved from the source cell to the target cell. In this case, after the initial cell handover, it is possible that not all candidate cells have completed UL synchronization. The UE uses the initial TA to perform the initial UL transmission.

[0190] Figure 13 This is a diagram representing a RACH (PDCCH ordered RACH) based on PDCCH indications used for candidate cells, without Random Access Response (RAR) monitoring. For Figure 13 This is only to explain the relationship with Figure 12 Differences. Figure 13 In the example, multiple candidate cells can be indicated in the PDCCH-based RACH indication (PDCCH order). The UE can also send the PRACH during the RACH process to the candidate cells for multiple TAG / TA acquisitions. Furthermore, the source cell does not send the RAR, but sends the TA indication in the cell handover command.

[0191] In this disclosure, a RACH without RAR can also be rewritten with a RACH without RAR monitoring (e.g., RACH without RAR monitoring). A RACH can also be rewritten with a PRACH transmission triggered by a PDCCH command. A RACH / PRACH transmission without RAR monitoring can also be rewritten with a RACH / PRACH transmission that does not require RAR monitoring, or a RACH / PRACH transmission that does not require RAR monitoring.

[0192] (analyze)

[0193] However, as mentioned above, when the timing advance (TA) for a candidate cell is indicated within the cell handover command, it is unclear how the NW (base station) indicates the TA to the UE. In this case, as mentioned above, the method for obtaining the TA indication (cell handover command) for the candidate cell can be any of the following: PRACH transmission triggered by a PDCCH command without RAR monitoring, UE-based TA measurement, or SRS-based TA measurement.

[0194] If the TA is not properly instructed to the UE, inter-cell mobility cannot be properly performed, and there is a concern about the deterioration of communication quality.

[0195] Therefore, the inventors of this invention studied the MAC CE structure for cell handover commands for candidate cells and came up with an example of this embodiment.

[0196] The embodiments disclosed herein will now be described in detail with reference to the accompanying drawings. Furthermore, the following methods (e.g., various scenarios) can be applied individually or in combination of at least two.

[0197] (Various rewrites, etc.)

[0198] In this disclosure, "A / B" and "at least one of A and B" may be rewritten as each other. In addition, in this disclosure, "A / B / C" may also mean "at least one of A, B and C".

[0199] In this disclosure, the terms "activate," "deactivate," "indicate," "select," "configure," "update," and "determine" can be overridden. Similarly, the terms "support," "control," "capable of control," "operate," and "capable of operation" can also be overridden.

[0200] In this disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher-level parameters, information elements (IEs), settings, etc., can also be modified interchangeably. In this disclosure, Medium Access Control (MAC) control elements (CEs), update commands, activation / deactivation commands, etc., can also be modified interchangeably.

[0201] In this disclosure, higher-layer signaling may be, for example, any one or a combination of Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, other messages (e.g., positioning protocol messages (e.g., NR Positioning Protocol A (NRPPa) / LTE Positioning Protocol (LPP) messages, messages from the core network), etc.)

[0202] In this disclosure, MAC signaling may also use, for example, a MAC Control Element (MACCE) or a MAC Protocol Data Unit (PDU). Broadcast information may also be, for example, a Master Information Block (MIB), a System Information Block (SIB), a Minimum System Information (Remaining Minimum System Information (RMSI)), or Other System Information (OSI).

[0203] In this disclosure, physical layer signaling may also be, for example, downlink control information (DCI), uplink control information (UCI), etc.

[0204] In the following implementations, "multiple" and "two" can be interchanged. Furthermore, "TAG" and "TAGID" can also be interchanged. Additionally, "cell," "CC," and "carrier" can also be interchanged. In the following implementations, "calculate," "derive," and "obtain" can also be interchanged.

[0205] The following description can be applied to inter-cell mobility (e.g., L1 / L2 inter-cell mobility) as well as to communication control outside of inter-cell mobility. L1 / L2 inter-cell mobility can also be rewritten with at least one of cell handover, cell switch, and cell change.

[0206] (Wireless communication method)

[0207] <First Implementation>

[0208] In the first embodiment, the MAC CE (cell handover command MAC CE) structure for cell handover commands for candidate cells will be described.

[0209] In this disclosure, the method for obtaining the TA indication can also be applied to at least one of PRACH transmission triggered by a PDCCH command, UE-based TA measurement, and SRS-based TA measurement.

[0210] The UE can also receive a Medium Access Control Element (MAC CE) containing at least one of the following: the ID of the serving cell after handover, the TCI status associated with that cell, the ID of the serving cell before handover, the TAG ID, and the Timing Advance Command (TAC). Based on the information contained in the MAC CE, the UE can perform cell handover. Furthermore, the UE can also determine the indication / application of the TA based on the information contained in the MAC CE (specifically, the TAG ID, TAC, etc.). This MAC CE can also be referred to as the Cell Handover Command MAC CE.

[0211] [TA's proposed scenario]

[0212] The UE can also envision the following options based on the candidate cell category set via higher-layer signaling, and the indication / application of the TA within the received MAC CE.

[0213] <The case where the candidate cell is set as the current serving cell via higher-level signaling>

[0214] •Opt1: The UE always assumes that the MAC CE (cell handover command MAC CE) for the candidate cell does not contain fields related to TA.

[0215] Opt2: The UE always assumes that the MAC CE (cell handover command MAC CE) for the candidate cell includes fields related to TA adjustment (e.g., a 6-bit TAC field).

[0216] Opt3: The UE always assumes that the MAC CE (cell handover command MAC CE) for the candidate cell includes a field for indicating the absolute TAC (e.g., a 12-bit absolute TAC field).

[0217] • Opt4: At least one of the following is indicated by this MAC CE: the presence (absence) of the TAC field, the exact meaning / definition of the TAC field, and the size of the TAC field. Additionally, OptC-1 / C-2 / C-3 (Opt4-1~Opt4-3) described later can also be applied to Opt4.

[0218] • Opt4-4: The cell handover command MAC CE can also indicate the presence of the TAC field. For example, the presence of this field can also mean that the TA is indicated / applied through the field associated with the TA adjustment (the 6-bit TAC field).

[0219] <The case where the candidate cell set via higher-level signaling is not the current serving cell (different from the current serving cell)>

[0220] • OptA: The UE always assumes that the MAC CE (cell handover command MAC CE) for the candidate cell does not contain fields related to TA.

[0221] • OptB: The UE always assumes that the MAC CE (cell handover command MAC CE) for the candidate cell includes a field for indicating the absolute TAC (e.g., a 12-bit absolute TAC field).

[0222] • OptC: At least one of the following is indicated by this MAC CE: the presence (absence) of the TAC field, the exact meaning / definition of the TAC field, and the size of the TAC field. Additionally, OptC-1 / C-2 / C-3 (Opt4-1~Opt4-3) can also be applied for Opt4.

[0223] • OptC-1: The cell handover command MAC CE can also indicate the presence of the TAC field. For example, the presence of this field can also mean that the TA is indicated / applied through the field used to indicate the absolute TAC (the 12-bit absolute TAC field).

[0224] OptC-2: The cell handover command MAC CE can also indicate whether the TAC field is a 6-bit TA adjustment field / a 12-bit absolute TAC field.

[0225] OptC-3: The cell handover command MAC CE can also represent the following three statuses.

[0226] (1) The TAC field does not exist.

[0227] (2) The TAC field exists, and the TAC field is a 12-bit absolute TAC field.

[0228] (3) The TAC field exists, and the TAC field is a 6-bit TA adjustment field.

[0229] In addition, each state in (1) to (3) can also be represented by 1-bit / 2-bit information (the I_TA field described later).

[0230] The above options can be indicated / set via higher-layer / physical-layer signaling, predefined by specifications, or reported by the UE capability. Furthermore, these settings can also be updated via higher-layer / physical-layer signaling.

[0231] The TA-related fields mentioned above can always be included in a MAC CE, or they can be included only under specific options. The TAC field can be included in a single MAC CE, or it can be included separately (on a per-MAC CE basis). That is, the TAC field can also be notified through another MAC CE.

[0232] In this disclosure, fields related to TA are included in the MAC CE, and TA is indicated by the MAC CE and can be interchanged. Furthermore, TA adjustment, TA adjustment, and TAG ID can also be interchanged. Additionally, absolute TAC, absolute TAC, and TAGID can also be interchanged.

[0233] [Field structure of the new MAC CE]

[0234] Next, the specific field structure of the cell handover command MAC CE will be explained. The fields within this MAC CE can be broadly categorized as follows:

[0235] • Fields used to indicate cell handover (fields related to cell handover)

[0236] • Fields used to indicate TA (fields related to TA).

[0237] The following items may also be used as fields for indicating cell handover. The MAC CE of this embodiment is not limited to the following items, and may further include at least one field shown in the serving cell change indication described above.

[0238] • Target cell ID (the ID of the serving cell after the handover).

[0239] • TCI status / SSB / CSI-RS associated with the target cell. These are used to inform the UE of either the DL beam or the DL / UL beam on the target cell.

[0240] • Target cell's UL beam / TCI status / spatial relationship / SSB / CSI-RS / SRS. These are used to enable the UE to identify the UL beam on the target cell.

[0241] • Source serving cell ID (the ID of the serving cell before the handover), or cell group ID containing the source serving cell (the ID of the cell group containing the serving cell before the handover).

[0242] •CAT (e.g., contained in CellAppTime_r18 set via RRC).

[0243] The UE can also be instructed to hand over multiple serving cells based on a single MAC CE. For example, multiple sets of the same fields as those listed above can also exist in this MAC CE.

[0244] • A bitmap indicating which source serving cell requires cell handover (1 bit is set for each serving cell or for each cell group ID corresponding to the source serving cell).

[0245] • Indicates at least one of the following fields for each source serving cell to which the cell handover is indicated: the target cell ID to be handed over, DL / joint TCI status / beam, UL TCI status / beam, and CAT.

[0246] The following items can also be applied as fields used to indicate TA.

[0247] ·TAG ID.

[0248] • Timing Advance Command (Adj.) used for adjustment (that is, TA adjustment field).

[0249] • Absolute TAC (Timing Advance Command (Abs.)) (that is, absolute TAC field).

[0250] Figures 14 to 17 This diagram illustrates an example of the MAC CE (cell handover command MAC CE) according to the first embodiment. Figures 14 to 17 In the diagram, the upper half of the fields related to cell handover are common. However, the lower half, with its one- or two-octet fields (related to TA), differs across diagrams. Specifically, in... Figure 14 The example shown is an example of a TA adjustment field. Figure 15 The example shown is an absolute TAC field. Figure 16 The example shown is a TA adjustment field that does not contain a TAG ID. Figure 17 An example of an absolute TAC field containing the TAG ID is shown. Additionally, in the following diagram, R can also represent a reserved bit (R=0).

[0251] like Figures 14 to 17 As shown in the fields related to cell handover, C0~C7 correspond to the source serving cell. For C0~C7, if it is "1", it means that a cell handover of the corresponding source serving cell will be performed; if it is "0", it means that a cell handover of the corresponding source serving cell will not be performed.

[0252] The Target Cell ID field is set to the ID of the target cell corresponding to the source serving cell (cells marked "1" in C0-C7) where the handover is taking place. The TCI state field is set to the ID of the TCI state corresponding to the source serving cell (cells marked "1" in C0-C7) where the handover is taking place. The size (number) of the Target Cell ID and TCI state fields is determined by the number of cells marked "1" in C0-C7 (and is variable).

[0253] The size of the Target Cell ID can also be set to a fixed size according to the specification or RRC settings. The target cell list (the PCI list of target cells) can also be set via RRC. Furthermore, the 4-bit cell ID of the MAC CE can also represent one of the target cells in the list (e.g., 16 cells) set via RRC.

[0254] like Figure 14 As shown, fields related to TA can also include, for example, a TAG ID field (e.g., 2 bits) and a TAC field (e.g., 6 bits). This field can also be combined with... Figure 8 The fields shown in the TAC MAC CE are the same. As mentioned above, this field can also be used after the initial access is established.

[0255] After initial access, the UE pre-identifies the absolute value of the TA for candidate cells. Therefore, for the value of the TA that should be applied, only the amount of adjustment (differential value) needs to be notified, for example, the TAC field can also be notified with a smaller number of 6 bits. On the other hand, the UE needs to identify the candidate cell (TAG) to which the TA is applied (which is not identified during handover), so it is preferable to be notified of the TAGID.

[0256] like Figure 15 As shown, fields related to TA can also include absolute TAC fields. This field can also be related to... Figure 9 The fields shown are the same for the absolute TAC MAC CE. For example, this field can also consist of 12 bits spanning two octets. As mentioned above, this field can also be used only during initial access.

[0257] During initial access, the UE pre-identifies which candidate cell to apply TA to. That is, the cell to which the TA is applied can also be the cell to which the connection was initially established. Therefore, in Figure 15In some cases, the TAG ID field may be omitted. That is, the UE identifies the common cell group (TAG) of the TA. On the other hand, the UE needs to identify the value of the TA to be applied (which was not identified during initial access), and therefore is preferably notified of an absolute TAC field representing the absolute value of the TA. Therefore, the absolute TAC field can also consist of 12 bits, which is larger than the 6-bit TAC field representing the amount of adjustment.

[0258] In addition, such as Figure 16 As shown, fields related to TA can also contain only a 6-bit TAC field. In this case, Figure 14 The TAG ID field shown can also be replaced with reserved bits. For example, it is also envisioned that the UE has identified the candidate cell (TAG) for applying TA in advance. Therefore, the TAG ID field may not necessarily be notified.

[0259] In addition, such as Figure 17 As shown, fields related to TA can also include a TAGID field in addition to the absolute TAC field. In this case, Figure 15 The amount of 3 bits in the 4-bit reserved bits shown can also be replaced with the TAGID field. For example, it is also envisioned that the UE does not recognize the TAG during initial access. In this case, the TAG ID can also be notified.

[0260] Thus, according to Figures 14-17 The example shown shows that, depending on the application scenario, the number of bits used for TA indication (the choice of which TA indication field should be notified) can be adjusted, thereby reducing the number of additional bits and appropriately controlling cell handover / TA indication.

[0261] [Transformation]

[0262] Figures 18A-18C ,as well as Figures 19A-19C These are diagrams illustrating variations of the MAC CE according to the first embodiment. In each of Figures 18 and 19, the fields related to TA are as described above. Figures 14-17 The fields are the same, therefore the explanation is omitted. That is, for Figures 18-19, the fields related to cell handover are the same as... Figures 14-17 They are different. Therefore, the main focus will be on explaining the differences.

[0263] For example, in Figures 14-17In the MAC CE, the fields related to cell handover are set to include the ID of each source serving cell, such as C0~C7. On the other hand, the target cell ID (corresponding to the first (1st)) is common in the source serving cell IDs (C0~C3), and the target cell ID (corresponding to the second (2nd)) is common in the source serving cell IDs (C4~C7). That is to say, the source serving cell ID may not necessarily be notified.

[0264] Therefore, as shown in Figures 18-19, the fields related to cell handover can also be configured to contain only the target cell ID, excluding the source serving cell ID. Specifically, in each of Figures 18-19, the first octet can, for example, contain a 2-bit UL BWP ID, a 2-bit DL BWP ID, and a 4-bit target cell ID. Thus, by configuring the representative target cell ID at the beginning (the first octet), the UE can appropriately identify the subsequent TA indication field within the (same) MAC CE after decoding the target cell ID in the MAC CE.

[0265] In addition, such as Figure 18C , Figures 19A-19C As shown, it may also include an I_TA field that indicates other indications related to TA. The I_TA field may be included within fields related to cell handover or within fields related to TA.

[0266] For example, Figure 18C The I_TA field can also indicate the presence (or absence) of the TA adjustment field. Figure 19A The I_TA field can also indicate the presence (absence) of the absolute TAC field. Figure 19B The I_TA field can also indicate the presence (existence) of the TA adjustment field / the presence (existence) of the absolute TAC field. Figure 19C The I_TA field can also indicate the presence (existence or absence) of the TA adjustment field / the presence (existence or absence) of the absolute TAC field / the presence (existence or absence) of the fields related to TA.

[0267] In addition, such as Figure 19B as well as Figure 19C As shown, the TA adjustment field and the absolute TAC field can also be included in the same MAC CE.

[0268] In this disclosure, the configuration, order, and number of bits of each field in MAC CE can be changed as appropriate.

[0269] According to the first embodiment described above, the UE can appropriately control the application of timing advance during cell handover.

[0270] <Supplement>

[0271] [Information notification to UE]

[0272] The notification of any information from the Network (NW) (e.g., Base Station (BS)) to the UE in the above-described embodiments (in other words, the reception of any information from the BS in the UE) can also 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 signals), or combinations thereof.

[0273] In the case where the above notification is made via MAC CE, the MAC CE can also be identified by including a new Logical Channel ID (LCID) in the MAC subheader that is not specified in the existing standard.

[0274] When the above notification is made through a DCI, the notification can also be made through specific fields of the DCI, the Radio Network Temporary Identifier (RNTI) used in the scrambling of the Cyclic Redundancy Check (CRC) bits assigned to the DCI, the format of the DCI, etc.

[0275] Furthermore, the notification of any information to the UE in the above embodiments can also be carried out periodically, semi-persistently, or non-periodically.

[0276] [Notification from UE]

[0277] The notification of any information from the UE (to the NW) in the above embodiments (in other words, the transmission / reporting of any information from the UE to the BS) can also be performed using physical layer signaling (e.g., UCI), higher layer signaling (e.g., RRC signaling, MACCE), specific signals / channels (e.g., PUCCH, PUSCH, PRACH, reference signals), or combinations thereof.

[0278] In the case where the above notification is delivered via MAC CE, the MAC CE can also be identified by including a new LCID in the MAC sub-header that is not specified in the existing standard.

[0279] In cases where the above notification is sent via UCI, the above notification may also be sent using PUCCH or PUSCH.

[0280] Furthermore, the notification of any information from the UE in the above embodiments can also be carried out periodically, semi-persistently, or non-periodically.

[0281] [Regarding the application of each implementation method]

[0282] At least one of the above-described implementation methods can also be applied under certain conditions. These specific conditions can be specified in the standard or communicated to the UE / BS using higher-layer signaling / physical layer signaling.

[0283] At least one of the above implementation methods may also be applied only to UEs that have reported a specific UE capability or support that specific UE capability.

[0284] This specific UE capability can also represent at least one of the following:

[0285] • Supports specific processing / operation / control / information for at least one of the above implementations (e.g., random access procedure / PRACH transmission without RAR monitoring).

[0286] • Supports methods for obtaining TA indications (e.g., PRACH transmission triggered by PDCCH command, UE-based TA measurement, SRS-based TA measurement).

[0287] • Supports receiving MAC CE commands for cell handover to candidate cells.

[0288] Furthermore, the aforementioned specific UE capabilities can be capabilities applied across the entire frequency range (commonly independent of frequency), capabilities for each frequency (e.g., one or a combination of cells, bands, band combinations, BWPs, component carriers, etc.), capabilities for each frequency range (e.g., Frequency Range 1 (FR1)), FR2, FR3, FR4, FR5, FR2-1, FR2-2), capabilities for each subcarrier spacing (SCS) or capabilities for each feature set (FS) or feature set per component-carrier (FSPC)

[0289] Furthermore, the aforementioned specific UE capabilities can be either capabilities that apply to all duplex modes (commonly regardless of the duplex mode) or capabilities that apply to each duplex mode (e.g., Time Division Duplex (TDD) and Frequency Division Duplex (FDD)).

[0290] Furthermore, at least one of the above-described embodiments can also be applied when the UE is set / activated / triggered by specific information associated with the above-described embodiments (or the operation of the above-described embodiments is performed) via higher-layer signaling / physical layer signaling. For example, this specific information may be information indicating activation of a random access procedure / PRACH transmission without RAR monitoring, arbitrary RRC parameters for a specific version (e.g., Rel. 18 / 19), etc.

[0291] The UE may also apply, for example, Rel.15 / 16 operations if it does not support at least one of the above-mentioned specific UE capabilities or if the above-mentioned specific information is not set.

[0292] (Postscript)

[0293] With respect to one embodiment of this disclosure, the following invention is noted.

[0294] [Appendix 1]

[0295] The terminal has:

[0296] The receiving unit receives the Medium Access Control Element (MAC CE) related to cell handover; and

[0297] The control unit determines the timing advance (TA) to be applied to UL transmission based on the information contained in the MAC CE.

[0298] The MAC CE includes at least one field related to cell handover and a field related to the TA.

[0299] [Appendix 2]

[0300] The terminal described in Appendix 1,

[0301] The control unit determines the TA based on the category of the candidate cell set through higher-layer signaling.

[0302] [Appendix 3]

[0303] The terminal described in Appendix 1 or Appendix 2,

[0304] The MAC CE includes at least one field related to TA adjustment and one field related to absolute TA command (TAC).

[0305] [Appendix 4]

[0306] The terminal described in any one of Appendix 1 to Appendix 3,

[0307] The MAC CE includes additional fields indicating the presence of fields related to the TA indication.

[0308] (Wireless communication system)

[0309] The structure of a wireless communication system according to one embodiment of this disclosure will now be described. In this wireless communication system, communication is performed using any one or a combination of the wireless communication methods according to the above embodiments of this disclosure.

[0310] Figure 20 This is a diagram illustrating an example of the schematic structure of a wireless communication system according to one embodiment. The wireless communication system 1 (also referred to simply as System 1) may also be a system that uses Long Term Evolution (LTE) or 5th generation mobile communication system New Radio (5GNR) as standardized by the Third Generation Partnership Project (3GPP).

[0311] Furthermore, the wireless communication system 1 can also support dual connectivity between multiple radio access technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC can also include dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), dual connectivity between NR and LTE (NR-E-UTRA Dual Connectivity (NE-DC)), etc.

[0312] 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.

[0313] Wireless communication system 1 can also support dual connectivity between multiple base stations within the same RAT (e.g., MN and SN are dual connectivity between NR base stations (gNB) (NR-NR Dual Connectivity (NN-DC))).

[0314] The wireless communication system 1 may also include a base station 11 forming a macro cell C1 with a relatively wide coverage area, and a base station 12 (12a-12c) configured within the macro cell C1 and forming a small cell C2 narrower than the macro cell C1. The user terminal 20 may also be located within at least one cell. The configuration and number of each cell and the user terminal 20 are not limited to the arrangement shown in the figure. Hereinafter, without distinguishing between base stations 11 and 12, they will be collectively referred to as base station 10.

[0315] User terminal 20 may also connect to at least one of multiple base stations 10. User terminal 20 may also utilize at least one of carrier aggregation (CA) using multiple component carriers (CC) and dual connectivity (DC).

[0316] Each CC can also be included in at least one of the first frequency band (Frequency Range 1 (FR1)) and the second frequency band (Frequency Range 2 (FR2)). Macro cell C1 can also be included in FR1, and small cell C2 can also be included in FR2. For example, FR1 can also be a frequency band below 6 GHz (sub-6 GHz), and FR2 can also be a frequency band above 24 GHz (above-24 GHz). In addition, the frequency bands, definitions, etc. of FR1 and FR2 are not limited to these; for example, FR1 can also correspond to a frequency band higher than FR2.

[0317] In addition, user terminal 20 can also use at least one of Time Division Duplex (TDD) and Frequency Division Duplex (FDD) to communicate in each CC.

[0318] Multiple base stations 10 can also be connected via wired (e.g., fiber optic, X2 interface, etc. based on Common Public Radio Interface (CPRI)) or wireless (e.g., NR communication). For example, when NR communication between base stations 11 and 12 is used as a backhaul, base station 11, which is equivalent to a host station, can also be referred to as an Integrated Access Backhaul (IAB) donor, and base station 12, which is equivalent to a relay station, can also be referred to as an IAB node.

[0319] Base station 10 may also be connected to core network 30 via other base stations 10 or directly. Core network 30 may include, for example, at least one of Evolved Packet Core (EPC), 5G Core Network (5GCN), Next Generation Core (NGC), etc.

[0320] The core network 30 may also include, for example, user plane functions (UPF), access and mobility management functions (AMF), session management functions (SMF), unified data management (UDM), application functions (AF), data network (DN), location management functions (LMF), and network functions (NF) such as operation, administration and maintenance (OAM). Alternatively, multiple functions can be provided through a single network node. Furthermore, communication with external networks (e.g., the Internet) can also be achieved via the DN.

[0321] User terminal 20 can also be a terminal that supports at least one of the following communication methods: LTE, LTE-A, 5G, etc.

[0322] In wireless communication system 1, wireless access methods based on Orthogonal Frequency Division Multiplexing (OFDM) can also be used. For example, in at least one of the downlink (DL) and uplink (UL) links, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), and Single Carrier Frequency Division Multiple Access (SC-FDMA) can also be used.

[0323] The wireless access method can also be referred to as a waveform. In addition, in the wireless communication system 1, other wireless access methods (e.g., other single-carrier transmission methods, other multi-carrier transmission methods) can also be used in the wireless access methods of UL and DL.

[0324] In the wireless communication system 1, the downlink channel can also be a shared downlink channel (Physical Downlink Shared Channel (PDSCH)), a broadcast channel (Physical Broadcast Channel (PBCH)), or a downlink control channel (Physical Downlink Control Channel (PDCCH)) shared by each user terminal 20.

[0325] In addition, in the wireless communication system 1, the uplink channel can also be the shared uplink channel (Physical Uplink Shared Channel (PUSCH)), the uplink control channel (Physical Uplink Control Channel (PUCCH)), the random access channel (Physical Random Access Channel (PRACH)) shared by each user terminal 20, etc.

[0326] User data, high-level control information, and System Information Blocks (SIBs) are transmitted via the PDSCH. User data and high-level control information can also be transmitted via the PUSCH. In addition, Master Information Blocks (MIBs) can also be transmitted via the PBCH.

[0327] Lower-layer control information can also be transmitted via PDCCH. This lower-layer control information may include, for example, downlink control information (DCI), which includes scheduling information for at least one of PDSCH and PUSCH.

[0328] Additionally, the DCI that schedules PDSCH can also be called DL allocation, DL DCI, etc., and the DCI that schedules PUSCH can also be called UL authorization, UL DCI, etc. Furthermore, PDSCH can be rewritten as DL data, and PUSCH can be rewritten as UL data.

[0329] In PDCCH detection, a Control Resource Set (CORESET) and a search space can also be utilized. A CORESET corresponds to the resources used to search for DCIs. The search space corresponds to the search area and search method for PDCCH candidates. A CORESET can also be associated with one or more search spaces. The UE can also monitor CORESETs associated with a specific search space based on search space settings.

[0330] A search space can also correspond to a PDCCH candidate corresponding to one or more aggregation levels. One or more search spaces can also be referred to as a search space set. In addition, the terms "search space", "search space set", "search space setting", "search space set setting", "CORESET", and "CORESET setting" in this disclosure can be rewritten interchangeably.

[0331] The PUCCH can also transmit uplink control information (uplink control information (UCI)) that includes at least one of the following: Channel State Information (CSI), delivery confirmation information (e.g., also known as Hybrid Automatic Repeat Request ACK Knowledge (HARQ-ACK), ACK / NACK, etc.), and Scheduling Request (SR). The PRACH can also transmit random access preambles used for establishing connections with the cell.

[0332] In addition, in this disclosure, downlink, uplink, etc., may be described without the word "link". Furthermore, various channels may be described without the word "physical".

[0333] In wireless communication system 1, synchronization signals (SS) and downlink reference signals (DL-RS) can also be transmitted. In wireless communication system 1, DL-RS can also transmit cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), demodulation reference signals (DMRS), positioning reference signals (PRS), and phase tracking reference signals (PTRS).

[0334] Synchronization signals can be, for example, at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). A signal block containing SS (PSS, SSS) and PBCH (and DMRS for PBCH) can also be called an SS / PBCH block, SS block (SSB), etc. In addition, SS, SSB, etc. can also be called reference signals.

[0335] Furthermore, in wireless communication system 1, the uplink reference signal (UL-RS) can also transmit measurement reference signals (sounding reference signals (SRS)) and demodulation reference signals (DMRS). Additionally, DMRS can also be referred to as user terminal-specific reference signals (UE-specific reference signals).

[0336] (Base station)

[0337] Figure 21 This diagram illustrates an example of the structure of a base station according to one embodiment. The base station 10 includes a control unit 110, a transmit / receive unit 120, a transmit / receive antenna 130, and a transmission path interface (transmission line interface) 140. Alternatively, the control unit 110, the transmit / receive unit 120, the transmit / receive antenna 130, and the transmission path interface 140 may each be provided in more than one manner.

[0338] Furthermore, while this example primarily illustrates the functional blocks of the characteristic portions of this embodiment, it can also be envisioned that the base station 10 also possesses other functional blocks required for wireless communication. Some of the processing of each unit described below may also be omitted.

[0339] The control unit 110 performs overall control of the base station 10. The control unit 110 can be composed of a controller, control circuit, etc., which are described based on common knowledge in the art to which this disclosure pertains.

[0340] The control unit 110 can also control signal generation and scheduling (e.g., resource allocation, mapping). The control unit 110 can also control transmission, reception, and measurement using the transmit / receive unit 120, transmit / receive antenna 130, and transmission path interface 140. The control unit 110 can also generate data, control information, sequences, etc., to be transmitted as signals and forward them to the transmit / receive unit 120. The control unit 110 can also perform call processing (setting, releasing, etc.) of the communication channel, status management of the base station 10, and management of wireless resources.

[0341] The transmitting / receiving unit 120 may also include a baseband unit 121, a radio frequency (RF) unit 122, and a measurement unit 123. The baseband unit 121 may also include a transmitting processing unit 1211 and a receiving processing unit 1212. The transmitting / receiving unit 120 may be composed of transmitters / receivers, RF circuits, baseband circuits, filters, phase shifters, measurement circuits, transmitting / receiving circuits, etc., as described based on common knowledge in the art to which this disclosure pertains.

[0342] The transmitting and receiving unit 120 can be configured as a single integrated transmitting and receiving unit, or it can be composed of a transmitting unit and a receiving unit. The transmitting unit can also be composed of a transmitting processing unit 1211 and an RF unit 122. The receiving unit can also be composed of a receiving processing unit 1212, an RF unit 122, and a measurement unit 123.

[0343] The transmitting and receiving antenna 130 can be constructed from an antenna, such as an array antenna, as described based on common knowledge in the art to which this disclosure pertains.

[0344] The transmitting / receiving unit 120 can also transmit the aforementioned downlink channel, synchronization signal, downlink reference signal, etc. The transmitting / receiving unit 120 can also receive the aforementioned uplink channel, uplink reference signal, etc.

[0345] The transmitting and receiving unit 120 may also use digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc., to form at least one of the transmitting beam and the receiving beam.

[0346] The transmitting and receiving unit 120 (transmitting processing unit 1211) may, for example, perform processing at the Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer (e.g., RLC retransmission control), and Medium Access Control (MAC) layer (e.g., HARQ retransmission control) on the data and control information obtained from the control unit 110, and generate a bit string to be transmitted.

[0347] The transmitting and receiving unit 120 (transmitting processing unit 1211) can also perform transmission processing such as channel coding (which may also include error correction coding), modulation, mapping, filter processing (filtering processing), Discrete Fourier Transform (DFT) processing (as needed), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion on the bit string to be transmitted, and output the baseband signal.

[0348] The transmitting and receiving unit 120 (RF unit 122) can also perform modulation, filtering, amplification, etc. on the baseband signal to the wireless frequency band, and transmit the wireless frequency band signal through the transmitting and receiving antenna 130.

[0349] On the other hand, the transmitting and receiving unit 120 (RF unit 122) can also amplify, filter, and demodulate the signals of the wireless frequency band received through the transmitting and receiving antenna 130 into the baseband signal.

[0350] The transmitting and receiving unit 120 (receiving and processing unit 1212) can also perform receiving and processing on the acquired baseband signal, including analog-to-digital conversion, Fast Fourier Transform (FFT) processing, Inverse Discrete Fourier Transform (IDFT) processing (as needed), filter processing, demapping, demodulation, decoding (which may also include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing, to acquire user data, etc.

[0351] The transmitting / receiving unit 120 (measurement unit 123) can also perform measurements related to the received signal. For example, the measurement unit 123 can also perform radio resource management (RRM) measurements, channel state information (CSI) measurements, etc., based on the received signal. The measurement unit 123 can also measure received power (e.g., Reference Signal Received Power (RSRP)), received quality (e.g., Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)), signal strength (e.g., Received Signal Strength Indicator (RSSI)), propagation path information (e.g., CSI), etc. The measurement results can also be output to the control unit 110.

[0352] The transmission path interface 140 can also transmit and receive signals (backhaul signaling) between the device included in the core network 30 (e.g., the network node providing the NF), other base stations 10, etc., and can also acquire and transmit user data (user plane data), control plane data, etc. for the user terminal 20.

[0353] In addition, the transmitting unit and receiving unit of the base station 10 in this disclosure may also be composed of at least one of a transmitting / receiving unit 120, a transmitting / receiving antenna 130, and a transmission path interface 140.

[0354] The transmitting and receiving unit 120 can also transmit a Medium Access Control Element (MAC CE) related to cell handover. The transmitting and receiving unit 120 can also receive a UL signal transmitted from the terminal based on a timing advance (TA) determined by the application terminal according to the information contained in the MAC CE.

[0355] The control unit 110 may also, in the case of a random access process that is configured to not have a PRACH response signal (RAR) under monitoring, indicate at least one of the following based on the presence or absence of a second PDCCH command or delivery confirmation message during a specific period: success or failure of PRACH, or retransmission of PRACH.

[0356] (User terminal)

[0357] Figure 22 This diagram illustrates an example of the structure 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. Alternatively, the control unit 210, the transmitting / receiving unit 220, and the transmitting / receiving antenna 230 may each be provided as one or more.

[0358] Furthermore, while this example primarily illustrates the functional blocks of the characteristic portions of this embodiment, it is also conceivable that the user terminal 20 may also have other functional blocks required for wireless communication. Some of the processing of each unit described below may also be omitted.

[0359] The control unit 210 performs overall control of the user terminal 20. The control unit 210 can be composed of a controller, control circuit, etc., which are described based on common knowledge in the technical field to which this disclosure pertains.

[0360] The control unit 210 can also control signal generation, mapping, etc. The control unit 210 can also control transmission, reception, measurement, etc., using the transmission / reception unit 220 and the transmission / reception antenna 230. The control unit 210 can also generate data, control information, sequences, etc., to be transmitted as signals and forward them to the transmission / reception unit 220.

[0361] The transmitting / receiving unit 220 may also include a baseband unit 221, an RF unit 222, and a measurement unit 223. The baseband unit 221 may also include a transmitting processing unit 2211 and a receiving processing unit 2212. The transmitting / receiving unit 220 may be composed of a transmitter / receiver, RF circuit, baseband circuit, filter, phase shifter, measurement circuit, transmitting / receiving circuit, etc., as described based on common knowledge in the art to which this disclosure pertains.

[0362] The transmitting and receiving unit 220 can be configured as a single integrated transmitting and receiving unit, or it can be composed of a transmitting unit and a receiving unit. The transmitting unit can also be composed of a transmitting processing unit 2211 and an RF unit 222. The receiving unit can also be composed of a receiving processing unit 2212, an RF unit 222, and a measurement unit 223.

[0363] The transmitting and receiving antenna 230 can be constructed from an antenna, such as an array antenna, as described based on common knowledge in the art to which this disclosure pertains.

[0364] The transmitting / receiving unit 220 can also receive the downlink channel, synchronization signal, downlink reference signal, etc., mentioned above. The transmitting / receiving unit 220 can also transmit the uplink channel, uplink reference signal, etc., mentioned above.

[0365] The transmitting and receiving unit 220 may also use digital beamforming (e.g., precoding), analog beamforming (e.g., phase rotation), etc., to form at least one of the transmitting beam and the receiving beam.

[0366] The transmitting and receiving unit 220 (transmitting processing unit 2211) may, for example, perform PDCP layer processing, RLC layer processing (e.g., RLC retransmission control), MAC layer processing (e.g., HARQ retransmission control) on the data and control information obtained from the control unit 210, and generate the bit string to be transmitted.

[0367] The transmitting and receiving unit 220 (transmitting processing unit 2211) can also perform channel coding (which may include error correction coding), modulation, mapping, filter processing, DFT processing (as needed), IFFT processing, precoding, digital-to-analog conversion and other transmission processing on the bit string to be transmitted, and output the baseband signal.

[0368] Furthermore, whether or not to apply DFT processing can be based on the settings of transform precoding. For a certain channel (e.g., PUSCH), if transform precoding is enabled, the transmit / receive unit 220 (transmit processing unit 2211) can perform DFT processing as described above in order to transmit the channel using the DFT-s-OFDM waveform. If not, the transmit / receive unit 220 (transmit processing unit 2211) can perform the above transmission processing without performing DFT processing.

[0369] The transmitting and receiving unit 220 (RF unit 222) can also perform modulation, filtering, amplification, etc. on the baseband signal to the wireless frequency band, and transmit the wireless frequency band signal through the transmitting and receiving antenna 230.

[0370] On the other hand, the transmitting and receiving unit 220 (RF unit 222) can also amplify, filter, demodulate, etc., the signals of the wireless frequency band received by the transmitting and receiving antenna 230.

[0371] The transmitting and receiving unit 220 (receiving and processing unit 2212) can also perform receiving and processing on the acquired baseband signal, such as analog-to-digital conversion, FFT processing, IDFT processing (as needed), filter processing, demapping, demodulation, decoding (which may also include error correction decoding), MAC layer processing, RLC layer processing, and PDCP layer processing, to acquire user data.

[0372] The transmitting / receiving unit 220 (measurement unit 223) can also perform measurements related to the received signal. For example, the measurement unit 223 can also perform RRM measurements, CSI measurements, etc., based on the received signal. The measurement unit 223 can 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 can also be output to the control unit 210.

[0373] Additionally, the measurement unit 223 can also derive channel measurements for CSI calculation based on channel measurement resources. Channel measurement resources can be, for example, non-zero power (NZP) CSI-RS resources. Furthermore, the measurement unit 223 can also derive interference measurements for CSI calculation based on interference measurement resources. Interference measurement resources can be at least one of NZP CSI-RS resources for interference measurement, CSI-Interference Measurement (IM) resources, etc. Additionally, CSI-IM can also be referred to as CSI-Interference Management (IM), and can be interchanged with zero power (ZP) CSI-RS. Furthermore, in this disclosure, CSI-RS, NZPCSI-RS, ZP CSI-RS, CSI-IM, CSI-SSB, etc., can also be interchanged.

[0374] Alternatively, the transmitting and receiving units of the user terminal 20 in this disclosure may also be composed of at least one transmitting / receiving unit 220 and transmitting / receiving antenna 230.

[0375] The transmitting / receiving unit 220 can also receive a Medium Access Control Element (MAC CE) related to cell handover. The transmitting / receiving unit 220 can also transmit a Random Access Channel (PRACH) based on a first PDCCH command. The MAC CE may also include at least one field related to cell handover and at least one field related to the TA. The MAC CE may also include at least one field related to TA adjustment and at least one field related to an absolute TA command (TAC). The MAC CE may also include other fields indicating the presence of fields related to TA indication.

[0376] The control unit 210 can also determine the timing advance (TA) applied to UL transmission based on the information contained in the MAC CE. The control unit 210 can also determine the TA based on the category of candidate cells set by higher-layer signaling.

[0377] (Hardware structure)

[0378] Furthermore, the block diagrams used in the description of the above embodiments illustrate functional units. These functional blocks (structural units) are implemented through any combination of at least one of hardware and software. Moreover, the implementation method of each functional block is not particularly limited. That is, each functional block can be implemented using a single device that is physically or logically combined, or it can be implemented by directly or indirectly (e.g., using wired, wireless, etc.) connecting two or more physically or logically separate devices. A functional block can also be implemented by combining the aforementioned single device or multiple devices with software.

[0379] Here, the functions include judgment, decision, determination, calculation, calculation, processing, export, investigation, search, confirmation, receiving, sending, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, regard as, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning, but are not limited to these. For example, a functional block (structural unit) that implements the sending function can also be called a transmitting unit, transmitter, etc. Each of these, as described above, is not particularly limited in its implementation method.

[0380] For example, in one embodiment of this disclosure, the base station, user terminal, etc., can also function as a computer for processing the wireless communication method of this disclosure. Figure 23 This diagram illustrates an example of the hardware structure of a base station and a user terminal according to one embodiment. The base station 10 and the user terminal 20 described above can also be physically configured as a computer device including a processor 1001, a memory 1002, a storage device 1003, a communication device 1004, an input device 1005, an output device 1006, and a bus 1007.

[0381] Furthermore, in this disclosure, terms such as apparatus, circuit, device, section, and unit can be interchanged. The hardware structure of base station 10 and user terminal 20 can be configured to include one or more of the apparatuses shown in the figures, or it can be configured not to include any of the apparatuses.

[0382] For example, only one processor 1001 is shown, but there can be multiple processors. Furthermore, processing can be performed by one processor, or simultaneously, sequentially, or by two or more processors using other methods. Additionally, processor 1001 can be implemented using more than one chip.

[0383] Regarding the functions in base station 10 and user terminal 20, for example, by reading specific software (programs) into hardware such as processor 1001 and memory 1002, so that processor 1001 performs calculations and controls communication via communication device 1004, or by controlling at least one of reading and writing data in memory 1002 and storage device 1003.

[0384] The processor 1001 enables the operating system to operate and control the computer as a whole. The processor 1001 may also be a central processing unit (CPU) that includes interfaces with peripheral devices, control devices, arithmetic devices, registers, etc. For example, at least a portion of the control unit 110 (210), the transmit / receive unit 120 (220), etc., described above may also be implemented by the processor 1001.

[0385] 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 performs various processes accordingly. As a program, a program that causes the computer to perform at least a portion of the operations described in the above embodiments can be used. For example, the control unit 110 (210) can also be implemented by a control program stored in the memory 1002 and operated in the processor 1001; similar implementations can be made for other functional blocks.

[0386] The memory 1002 may also be a computer-readable recording medium, such as being composed of at least one of a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), or other suitable storage media. The memory 1002 may also be referred to as a register, cache, main memory (main storage device), etc. The memory 1002 is capable of storing executable programs (program code), software modules, etc., for implementing the wireless communication method according to an embodiment of this disclosure.

[0387] Storage device 1003 may also be a computer-readable recording medium, such as a flexible disc, floppy disk, optical disk (e.g., a compact disc ROM), digital multifunction disk, Blu-ray disc, removable disk, hard disk drive, smart card, flash memory device (e.g., a card, stick, key drive), magnetic stripe, database, server, or at least one other suitable storage medium. Storage device 1003 may also be referred to as an auxiliary storage device.

[0388] The communication device 1004 is hardware (transmitting and receiving device) used for communication between computers via at least one of a wired network and a wireless network. It is also referred to as a network device, network controller, network interface card (NIC), communication module, etc. To implement at least one of, for example, Frequency Division Duplex (FDD) and Time Division Duplex (TDD), the communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. For example, the aforementioned transmit / receive unit 120 (220) and transmit / receive antenna 130 (230) may also be implemented by the communication device 1004. The transmit / receive unit 120 (220) may also be implemented by physically or logically separating the transmit unit 120a (220a) and the receive unit 120b (220b).

[0389] Input device 1005 is an input device that receives input from external sources (e.g., keyboard, mouse, microphone, switch, button, sensor, etc.). Output device 1006 is an output device that performs output to external sources (e.g., display, speaker, light-emitting diode (LED) lamp, etc.). Alternatively, input device 1005 and output device 1006 can also be an integrated structure (e.g., a touch panel).

[0390] Furthermore, the processor 1001, memory 1002, and other devices are connected via a bus 1007 for communicating information. The bus 1007 can be configured as a single bus or as different buses between the devices.

[0391] Furthermore, the base station 10 and the user terminal 20 can also be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA), and can also use this hardware to implement part or all of the functional blocks. For example, the processor 1001 can also be implemented using at least one of these hardware components.

[0392] (Variation example)

[0393] Furthermore, the terms described in this disclosure, as well as those necessary for understanding this disclosure, may be replaced with terms that have the same or similar meanings. For example, channel, symbol, and signal (signal or signaling) may be interchanged. Additionally, a signal may also be a message. A reference signal can also be abbreviated as RS, and may be referred to as pilot, pilot signal, etc., depending on the applied standard. Furthermore, a component carrier (CC) may also be referred to as cell, frequency carrier, carrier frequency, etc.

[0394] A radio frame can also be composed of one or more periods (frames) in the time domain. Each of these periods (frames) that constitute a radio frame can also be called a subframe. Furthermore, a subframe can also be composed of one or more time slots in the time domain. A subframe can also be a fixed time length (e.g., 1 ms) independent of the parameter set (numerology).

[0395] Here, the parameter set can also be communication parameters applied in at least one of the transmission and reception of a signal or channel. For example, the parameter set can also represent 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 structure, specific filtering processing performed by the transmitter and receiver in the frequency domain, and specific windowing processing performed by the transmitter and receiver in the time domain.

[0396] In the time domain, a time slot can also be composed of one or more symbols (Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.). In addition, a time slot can also be a time unit based on a set of parameters.

[0397] A time slot can also contain multiple mini-time slots. Each mini-time slot can also consist of one or more symbols in the time domain. Furthermore, a mini-time slot can also be called a sub-time slot. A mini-time slot can also consist of fewer symbols than a time slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a mini-time slot can also be called PDSCH (PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using mini-time slots can also be called PDSCH (PUSCH) mapping type B.

[0398] Radio frames, subframes, time slots, mini-time slots, and symbols all represent time units for transmitting signals. Radio frames, subframes, time slots, mini-time slots, and symbols can also use their respective other names. Furthermore, the time units such as frames, subframes, time slots, mini-time slots, and symbols in this disclosure can be interchanged.

[0399] For example, a subframe can also be called a TTI, multiple consecutive subframes can also be called a TTI, and a time slot or a mini-time slot can also be called a TTI. That is, at least one of a subframe and a TTI can be a subframe in existing LTE (1ms), a period shorter than 1ms (e.g., 1-13 symbols), or a period longer than 1ms. In addition, the unit representing TTI may not be called a subframe, but rather a time slot, mini-time slot, etc.

[0400] Here, TTI refers, for example, to the smallest unit of time for scheduling in wireless communication. For instance, in an LTE system, the base station schedules radio resources (frequency bandwidth, transmit power, etc., available to each user terminal) in TTI units. However, the definition of TTI is not limited to this.

[0401] TTI can also be a unit of time for transmitting channel-coded data packets (transmission blocks), code blocks, codewords, etc., and can also be a unit of processing such as scheduling and link adaptation. In addition, when a TTI is given, the actual time interval (e.g., the number of symbols) mapped to transmission blocks, code blocks, codewords, etc. can be shorter than the TTI.

[0402] Additionally, where a time slot or a mini-time slot is referred to as a TTI, more than one TTI (i.e., more than one time slot or more than one mini-time slot) can also serve as the minimum time unit for scheduling. Furthermore, the number of time slots (mini-time slots) constituting the minimum time unit of the schedule can also be controlled.

[0403] A TTI with a duration of 1ms can also be referred to as a normal TTI (TTI in 3GPPRel.8-12), a standard TTI, a long TTI, a normal subframe, a standard subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI can also be referred to as a shortened TTI, a short TTI, a partial TTI (partial or fractional TTI), a shortened subframe, a short subframe, a mini time slot, a sub-time slot, a time slot, etc.

[0404] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) can also be rewritten as a TTI with a duration of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) can also be rewritten as a TTI with a duration of less than a long TTI but more than 1 ms.

[0405] A resource block (RB) is a unit of resource allocation in both the time and frequency domains. In the frequency domain, it can also contain one or more consecutive subcarriers. The number of subcarriers in an RB can be the same regardless of the parameter set, for example, it can be 12. The number of subcarriers in an RB can also be determined based on the parameter set.

[0406] Furthermore, an RB can contain one or more symbols in the time domain, and can also be a time slot, a mini-time slot, a subframe, or the length of a TTI. A TTI, a subframe, etc., can also be composed of one or more resource blocks.

[0407] In addition, one or more RBs can also be referred to as Physical Resource Blocks (PRBs), Sub-Carrier Groups (SCGs), Resource Element Groups (REGs), PRB pairs, RB pairs, etc.

[0408] In addition, a resource block can also consist of one or more resource elements (REs). For example, an RE can also be a radio resource area consisting of a subcarrier and a symbol.

[0409] The Bandwidth Part (BWP) (also referred to as partial bandwidth, etc.) can also represent a subset of consecutive common resource blocks (RBs) used for a certain parameter set in a certain carrier. Here, common RBs can also be determined by the index of RBs based on the common reference point of the carrier. PRBs can also be defined in a BWP and appended with numbers within that BWP.

[0410] A BWP can also include a UL BWP (the BWP used by UL) and a DL BWP (the BWP used by DL). For a UE, one or more BWPs can also be set within a single carrier.

[0411] At least one of the configured BWPs can be active, and the UE may not intend to transmit or receive specific signals / channels outside of the active BWPs. Additionally, terms such as "cell" and "carrier" in this disclosure may be replaced with "BWP".

[0412] Furthermore, the structures described above, such as radio frames, subframes, time slots, mini-time slots, and symbols, are merely illustrative. For example, the number of subframes contained in a radio frame, the number of time slots in each subframe or radio frame, the number of mini-time slots contained within a time slot, the number of symbols and RBs contained in a time slot or mini-time slot, the number of subcarriers contained in an RB, and the number of symbols in a TTI, symbol length, and cyclic prefix (CP) length can be varied in many ways.

[0413] Furthermore, the information, parameters, etc., described in this disclosure can be represented by absolute values, relative values ​​with respect to a specific value, or other corresponding information. For example, wireless resources can also be indicated by a specific index.

[0414] In this disclosure, the names used for parameters, etc., are not limiting names in any respect. Furthermore, the mathematical expressions, etc., using these parameters may differ from those explicitly disclosed in this disclosure. Various channels (PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name; therefore, the various names assigned to these various channels and information elements are not limiting names in any respect.

[0415] The information, signals, etc., described in this disclosure can also be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc., which may be mentioned throughout the above description, can also be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination thereof.

[0416] Furthermore, information, signals, etc., can be output in at least one of the following directions: from higher level (upper layer) to lower level (lower layer), and from lower layer to higher level. Information, signals, etc., can also be input and output via multiple network nodes.

[0417] Input and output information, signals, etc., can be stored in a specific location (e.g., memory) or managed using a management table. Input and output information, signals, etc., can be overwritten, updated, or appended. Output information, signals, etc., can also be deleted. Input information, signals, etc., can also be sent to other devices.

[0418] The notification of information is not limited to the methods / implementations described in this disclosure, and may also be carried out by other methods. For example, the notification of information in this disclosure may also be implemented by physical layer signaling (e.g., downlink control information (DCI), uplink control information (UCI), etc.), higher layer signaling (e.g., radio resource control (RRC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB) etc.), medium access control (MAC) signaling), other signals, or combinations thereof.

[0419] In addition, physical layer signaling can also be referred to as Layer 1 / Layer 2 (L1 / L2) control information (L1 / L2 control signals), L1 control information (L1 control signals), etc. Furthermore, RRC signaling can also be referred to as RRC messages, such as RRC connection setup messages, RRC connection reconfiguration messages, etc. Additionally, MAC signaling can also be notified using, for example, the MAC control element (CE).

[0420] Furthermore, notification of specific information (e.g., a notification of “is X”) is not limited to explicit notification, but can also be implicit (e.g., by not providing that specific information, or by providing other information).

[0421] The determination can be made by a value represented by a single bit (0 or 1), by a true or false value (boolean), or by a numerical comparison (e.g., a comparison with a specific value).

[0422] Whether software is called software, firmware, middleware, microcode, hardware description language, or any other name, it should be broadly interpreted to refer to instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0423] Furthermore, software, instructions, and information can also be sent and received via a transmission medium. For example, when software is sent from a website, server, or other remote source using at least one of wired technologies (coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL) etc.) and wireless technologies (infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0424] The terms “system” and “network” as used in this disclosure are interchangeable. “Network” may also mean devices included in a network (e.g., base stations).

[0425] In this disclosure, the terms “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”, “beamwidth”, “beam angle”, “antenna”, “antenna element”, “panel”, “UE panel”, “transmitting entity”, and “receiving entity” are used interchangeably.

[0426] Furthermore, in this disclosure, the antenna port can also be rewritten with an antenna port used for any signal / channel (e.g., a DeModulation Reference Signal (DMRS) port). In this disclosure, resources can also be rewritten with resources used for any signal / channel (e.g., reference signal resources, SRS resources, etc.). Additionally, resources can also include time / frequency / code / space / power resources. Moreover, the spatial domain transmission filter can also include at least one of a spatial domain transmission filter and a spatial domain reception filter.

[0427] The aforementioned groups may include, for example, at least one of the following: spatial relation group, code division multiplexing (CDM) group, reference signal (RS) group, control resource set (CORESET) group, PUCCH group, antenna port group (e.g., DMRS port group), layer group, resource group, beam group, antenna group, panel group, etc.

[0428] Furthermore, in this disclosure, beam, SRS Resource Indicator (SRI), CORESET, CORESET pool, PDSCH, PUSCH, Codeword (CW), Transport Block (TB), RS, etc., can also be rewritten to each other.

[0429] Furthermore, in this disclosure, the TCI state, downlink TCI state (DL TCI state), uplink TCI state (UL TCI state), unified TCI state, common TCI state, and joint TCI state can also be rewritten to each other.

[0430] Furthermore, in this disclosure, terms such as "QCL", "QCL concept", "QCL relationship", "QCL type information", "QCL property (QCLproperty / properties)", "specific QCL type (e.g., type A, type D) property", and "specific QCL type (e.g., type A, type D)" can be rewritten interchangeably.

[0431] In this disclosure, indexes, identifiers (IDs), indicators, indications, resource IDs, etc., can be interchanged. Sequences, lists, sets, groups, clusters, subsets, etc., can also be interchanged.

[0432] Furthermore, the spatial relationship information Identifier (ID) (TCI state ID) and spatial relationship information (TCI state) can be interchanged. "Spatial relationship information (TCI state)" can also be interchanged with "a set of spatial relationship information (TCI states)," "one or more spatial relationship information," etc. TCI state and TCI can also be interchanged. Spatial relationship information and spatial relationships can also be interchanged.

[0433] In this disclosure, the terms "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" are used interchangeably. There are also instances where the terms macro cell, small cell, femtocell, and picocell are used to refer to a base station.

[0434] A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, its overall coverage area can be divided into several smaller areas, each of which can also provide communication services through a base station subsystem (e.g., a small indoor base station (Remote Radio Head (RRH))). Terms such as "cell" or "sector" refer to a portion or all of the coverage area of ​​at least one of the base station and base station subsystem providing communication services within that coverage area.

[0435] In this disclosure, the act of a base station sending information to a terminal can also be rewritten in relation to the act of the base station instructing the terminal to perform control / operation based on that information.

[0436] In this disclosure, the terms “Mobile Station (MS)”, “user terminal”, “user equipment (UE)”, and “terminal” are used interchangeably.

[0437] There are also instances where mobile stations are referred to as subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless terminals, remote terminals, handsets, user agents, mobile clients, clients, or several other appropriate terms.

[0438] At least one of the base station and the mobile station can also be referred to as a transmitting device, a receiving device, a wireless communication device, etc. Additionally, at least one of the base station and the mobile station can also be a device mounted on a moving object, the moving object itself, etc.

[0439] The term "mobile body" refers to a movable object whose speed is arbitrary, including when the object is stationary. Examples of such mobile bodies include vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships (ships and other watercraft), airplanes, rockets, artificial satellites, drones, multicopters, quadcopters, hot air balloons, and objects carried on them, but are not limited to these. Furthermore, the mobile body can also be a mobile body that moves autonomously based on operational commands.

[0440] The mobile entity can be a means of transportation (e.g., a vehicle, an airplane, etc.), a mobile entity moving in an unmanned manner (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanized or unmanned). Additionally, at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station can also be an Internet of Things (IoT) device such as a sensor.

[0441] Figure 24 This is a diagram illustrating 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 speed sensor 51, a 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.

[0442] The drive unit 41 is comprised of at least one of an engine, a motor, or a combination of an engine and a motor. The steering unit 42 is configured to include at least a steering wheel (also called a steering handle) that steers at least one of the front wheels 46 and the rear wheels 47 based on operation of the steering wheel by the user.

[0443] The electronic control unit 49 consists of a microprocessor 61, a memory (ROM, RAM) 62, and a communication port (e.g., an input / output (IO) port) 63). Signals from various sensors 50-58 present in the vehicle are input to the electronic control unit 49. The electronic control unit 49 can also be referred to as an electronic control unit (ECU).

[0444] The signals from various sensors 50-58 include the following: current signal from current sensor 50 sensing the current of the motor; rotational speed signal of front wheel 46 / rear wheel 47 obtained by speed sensor 51; air pressure signal of front wheel 46 / rear wheel 47 obtained by air pressure sensor 52; vehicle speed signal obtained by vehicle speed sensor 53; acceleration signal obtained by acceleration sensor 54; accelerator pedal 43 depress amount signal obtained by accelerator pedal sensor 55; brake pedal 44 depress amount signal obtained by brake pedal sensor 56; shift lever 45 operation signal obtained by shift lever sensor 57; and detection signal obtained by object detection sensor 58 for detecting obstacles, vehicles, pedestrians, etc.

[0445] The information service unit 59 comprises various devices such as a navigation system, audio system, speakers, display, television, and radio, used to provide (output) various information such as driving information, traffic information, and entertainment information, and one or more ECUs that control these devices. The information service unit 59 uses information obtained from external devices via the communication module 60, etc., to provide various information / services (e.g., multimedia information / multimedia services) to the occupants of the vehicle 40.

[0446] The information service unit 59 may include input devices (e.g., keyboard, mouse, microphone, switch, button, sensor, touch panel, etc.) that accept input from the outside, and output devices (e.g., display, speaker, LED light, touch panel, etc.) that implement output to the outside.

[0447] The driver assistance system unit 64 comprises various devices used to provide functions for preventing accidents or reducing the driver's workload, such as millimeter-wave radar, light detection and ranging (LiDAR), cameras, positioning detectors (e.g., Global Navigation Satellite System (GNSS), map information (e.g., High Definition (HD) maps, Autonomous Vehicle (AV) maps), gyroscope systems (e.g., Inertial Measurement Unit (IMU), Inertial Navigation System (INS)), artificial intelligence (AI) chips, and AI processors, and one or more ECUs that control these devices. Furthermore, the driver assistance system unit 64 sends and receives various information via communication module 60 to realize driver assistance functions or autonomous driving functions.

[0448] The communication module 60 can communicate with the microprocessor 61 and the structural elements of the vehicle 40 via the communication port 63. For example, the communication module 60 sends and receives data (information) with the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, gear shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, microprocessor 61 and memory (ROM, RAM) 62 in the electronic control unit 49 of the vehicle 40, and various sensors 50-58 via the communication port 63.

[0449] The communication module 60 can be controlled by the microprocessor 61 of the electronic control unit 49 and is a communication device capable of communicating with external devices. For example, it can transmit and receive various types of information with external devices via wireless communication. The communication module 60 can be located both inside and outside the electronic control unit 49. The external device can be, for example, the aforementioned base station 10, user terminal 20, etc. Furthermore, the communication module 60 can be, for example, at least one of the aforementioned base station 10 and user terminal 20 (or it can function as at least one of the base station 10 and user terminal 20).

[0450] The communication module 60 can also wirelessly transmit at least one of the signals input to the electronic control unit 49 from the various sensors 50-58 described above, the information obtained based on these signals, and the information based on input from an external (user) source obtained via the information service unit 59 to an external device. The electronic control unit 49, the various sensors 50-58, the information service unit 59, etc., can also be referred to as input units that receive input. For example, the PUSCH transmitted via the communication module 60 can also contain information based on the aforementioned inputs.

[0451] The communication module 60 receives various information (traffic information, signal information, workshop information, etc.) sent from external devices and displays it on the vehicle's information service unit 59. The information service unit 59 can also be referred to as an output unit that outputs information (for example, outputs information to devices such as displays and speakers based on the PDSCH received by the communication module 60 (or the data / information decoded from the PDSCH).

[0452] Furthermore, the communication module 60 stores various types of information received from external devices into a memory 62 that can be utilized by the microprocessor 61. Based on the information stored in the memory 62, the microprocessor 61 can also control the drive unit 41, steering unit 42, accelerator pedal 43, brake pedal 44, gear shift lever 45, left and right front wheels 46, left and right rear wheels 47, axles 48, and various sensors 50-58, etc., of the vehicle 40.

[0453] Furthermore, the base station in this disclosure can also be rewritten as a user terminal. For example, various methods / implementations of this disclosure can be applied to structures where communication between the base station and the user terminal is replaced by communication between multiple user terminals (e.g., also referred to as device-to-device (D2D) or vehicle-to-everything (V2X)). In this case, it can also be configured such that the user terminal 20 has the functions of the base station 10 described above. In addition, terms such as "uplink" and "downlink" can be rewritten as terms corresponding to inter-terminal communication (e.g., "sidelink"). For example, uplink channel, downlink channel, etc., can also be rewritten as sidelink channel.

[0454] Similarly, the user terminal in this disclosure can also be rewritten as a base station. In this case, it can also be configured such that the base station 10 has the functions of the user terminal 20 described above.

[0455] In this disclosure, operations are assumed to be performed by the base station, and sometimes, depending on the circumstances, by its upper node. In a network containing one or more network nodes having a base station, the various operations performed for communication with a terminal can obviously be performed by the base station, one or more network nodes other than the base station (e.g., considering a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc., but not limited to these), or combinations thereof.

[0456] The various methods / implementations described in this disclosure can be used individually or in combination, and can be switched as needed during execution. Furthermore, the processing procedures, timing sequences, flowcharts, etc., of the various methods / implementations described in this disclosure can be rearranged as long as they do not contradict each other. For example, for the method described in this disclosure, the illustrated order is used to indicate various steps, but the order in which they are indicated is not limited.

[0457] The various methods / implementations described in this disclosure can also be applied to 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 a decimal)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New Radio Access (NX), Futuregeneration Radio Access (FX), Global System for Mobile Communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE This includes 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-Wideband (UWB)), Bluetooth (registered trademark), systems utilizing other suitable wireless communication methods, and next-generation systems derived from, modified, generated, or specified based on these methods. Furthermore, multiple systems can be combined (e.g., LTE or LTE-A, combinations with 5G, etc.) for application.

[0458] As used in this disclosure, the term "based on" does not mean "based on only" unless otherwise specified. In other words, the term "based on" means both "based on only" and "based on at least".

[0459] Any reference to an element using the designations "first," "second," etc., as used in this disclosure does not comprehensively limit the quantity or order of these elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Therefore, reference to the first and second elements does not imply that only two elements may be used, or that the first element must take precedence over the second element in some form.

[0460] The term "determining" as used in this disclosure can encompass a wide variety of operations. For example, "determining" can also refer to judging, calculating, computing, processing, deriving, investigating, looking up (search, inquiry) (e.g., searching in a table, database or other data structure), and ascertaining.

[0461] In addition, "judgment (decision)" can also refer to receiving (e.g., receiving information), transmitting (e.g., sending information), inputting, outputting, accessing (e.g., accessing data in memory), etc., as situations where "judgment (decision)" is performed.

[0462] Furthermore, "judgment (decision)" can also refer to situations where resolving, selecting, choosing, establishing, or comparing are considered as making a "judgment (decision)". That is, "judgment (decision)" can also refer to certain operations as making a "judgment (decision)". In this disclosure, "judgment (decision)" can also be rewritten in relation to the operations described above.

[0463] Furthermore, in this disclosure, "determine / determining" can also be interchanged with "assume / assuming," "expect / expecting," "consider / considering," etc. Additionally, in this disclosure, "not assuming to proceed..." can also be interchanged with "assuming not to proceed..."

[0464] In this disclosure, "expect" can also be interchanged with "be expected." For example, "expect(s) ..." (where "..." can also be expressed using a that clause, to infinitive, etc.) can also be interchanged with "be expected ...." "Does not expect..." can also be interchanged with "be not expected...". Furthermore, "An apparatus A is not expected..." can also be interchanged with "Apparatus B other than apparatus A does not expect..." (for example, if apparatus A is a UE, apparatus B can also be a base station).

[0465] The term "maximum transmit power" as used in this disclosure may refer to the maximum value of the transmit power, the nominal maximum transmit power (the nominal UE maximum transmit power), or the rated maximum transmit power (the rated UE maximum transmit power).

[0466] As used in this disclosure, the terms “connected,” “coupled,” or all variations thereof, refer to all direct or indirect connections or combinations between two or more elements, and can include cases where there is one or more intermediate elements between two mutually “connected” or “coupled” elements. The connections or combinations between elements can be physical, logical, or a combination thereof. For example, “connection” can also be rewritten as “access.”

[0467] In this disclosure, when two elements are connected, it is possible to consider using more than one wire, cable, printed electrical connection, etc. to be "connected" or "combined" with each other, and as several non-limiting and non-exclusive examples, to use electromagnetic energy with wavelengths having wireless frequency domain, microwave region, light (both visible and invisible) region to be "connected" or "combined" with each other.

[0468] In this disclosure, the term "A is different from B" can also mean "A and B are different from each other." Additionally, the term can also mean "A and B are each different from C." Terms such as "separate" and "combined" can also be interpreted in the same way as "different."

[0469] When the terms "include," "including," and variations thereof are used in this disclosure, these terms, like the term "comprising," mean inclusive. Furthermore, the term "or" as used in this disclosure does not mean XOR.

[0470] In this disclosure, for example, in cases where articles are added through translation, such as a, an, and the in English, the disclosure may also include cases where the noun following these articles is in a plural form.

[0471] In this disclosure, words such as "below," "less than," "above," "more than," and "equal to" can be interchanged. Furthermore, in this disclosure, words meaning "good," "bad," "large," "small," "high," "low," "early," "slow," "wide," and "narrow," etc., are not limited to the positive, comparative, and superlative degrees, and can be interchanged. Additionally, in this disclosure, words meaning "good," "bad," "large," "small," "high," "low," "early," "slow," "wide," and "narrow," etc., as expressions with "i" appended (i being any integer), are not limited to the positive, comparative, and superlative degrees, and can be interchanged (for example, "highest" can also be interchanged with "i-th highest").

[0472] In this disclosure, "of", "for", "regarding", "related to", "associated with", etc., can also be rewritten interchangeably.

[0473] In this disclosure, phrases such as "when A, B", "if A, then B", "B upon A", "B in response to A", "based on A", "B during / while A", "before A", "at the same time as / on A", "after A", "since A", and "until A" can be rewritten interchangeably. Furthermore, A and B can be replaced with nouns, gerunds, or ordinary sentences, depending on the context. Additionally, the time difference between A and B can be approximately 0 (immediately following or immediately preceding). Moreover, a time offset can be applied to the time A occurs. For example, "A" can be rewritten interchangeably with "before / after the time offset of A". This time offset (e.g., more than one symbol / slot) can be predetermined or determined by the UE based on the information it is notified of.

[0474] In this disclosure, timing, moment, time, time instance, arbitrary time unit (e.g., time slot, sub-time slot, symbol, subframe), period, opportunity, resource, etc., can also be overridden.

[0475] The inventions disclosed herein have been described in detail above. However, it will be apparent to those skilled in the art that the inventions disclosed herein are not limited to the embodiments described herein. The description herein is for illustrative purposes only and is not intended to limit the inventions disclosed herein in any way.

Claims

1. A terminal, comprising: The receiving unit receives the Media Access Control (MAC) CE element related to cell handover; and The control unit, based on the information contained in the MAC CE, determines the timing advance TA to be applied to the UL transmission. The MAC CE includes at least one of the fields related to cell handover and the fields related to the TA.

2. The terminal according to claim 1, wherein, The control unit determines the TA based on the category of the candidate cell set through higher-layer signaling.

3. The terminal according to claim 1, wherein, The MAC CE includes at least one of the fields related to TA adjustment and the field related to the absolute TA command TAC.

4. The terminal according to claim 1, wherein, The MAC CE includes additional fields indicating the presence of fields related to the TA indication.

5. A wireless communication method for a terminal, comprising: The steps for receiving the Media Access Control (MAC) CE element related to cell handover; and Based on the information contained in the MAC CE, determine the step for the timing advance TA applied to the UL transmission. The MAC CE includes at least one of the fields related to cell handover and the fields related to the TA.

6. A base station, comprising: The transmitting unit transmits the Media Access Control (MAC) CE element related to cell handover; and The receiving unit receives the UL signal sent from the terminal by the application terminal based on the timing advance TA determined by the application terminal according to the information contained in the MAC CE. The MAC CE includes at least one of the fields related to cell handover and the fields related to the TA.

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