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 reception unit that receives a physical downlink control channel (PDCCH) command that includes information relating to transmission of a physical random access channel (PRACH) to a plurality of candidate cells; and a control unit that controls the transmission of the PRACH for each of the plurality of candidate cells. According to one embodiment of the present disclosure, it is possible to appropriately perform PRACH transmission for each candidate cell.

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 Telecommunication 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 (3rd 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] In future wireless communication systems, the application of L1L2-triggered mobility (LTM) is being studied. LTM envisions the following: for a terminal (user terminal, user equipment (UE)), candidate cells are assigned separately from the serving cell, and handover between the serving cell and candidate cells occurs.

[0009] However, it remains unclear how the UE should transmit the Physical Random Access Channel (PRACH) for each candidate cell when multiple candidate cells are configured / indicated. Improper implementation of PRACH transmission for each candidate cell could lead to concerns about degraded communication quality with candidate cells after cell handover.

[0010] This disclosure is made in view of this purpose, and one of its objectives is to provide a terminal, wireless communication method, and base station capable of appropriately performing PRACH transmissions for each candidate cell.

[0011] Methods for solving problems

[0012] The terminal according to one aspect of this disclosure is characterized by having: a receiving unit for receiving a Physical Downlink Control Channel (PDCCH) command containing information related to the transmission of Physical Random Access Channel (PRACH) for a plurality of candidate cells; and a control unit for controlling the transmission of the PRACH for each of the plurality of candidate cells.

[0013] Invention Effects

[0014] According to one method of this disclosure, PRACH transmissions for each candidate cell can be appropriately performed. Attached Figure Description

[0015] Figure 1A This is a diagram illustrating an example of UE movement in Rel.17. Figure 1B This is a diagram illustrating an example of UE movement in Rel.18.

[0016] Figure 2 This is a diagram illustrating an example of the LTM process.

[0017] Figure 3 This is a diagram illustrating an example of comparing L3 handover with LTM in Rel.18.

[0018] Figure 4 This is a diagram illustrating an example of the association between a serving cell and a candidate cell.

[0019] Figure 5A This is a diagram representing the second example of option 2 for candidate cell settings. Figure 5B This is a diagram representing the third example of option 2 for candidate cell settings.

[0020] Figure 6 This is a diagram illustrating example 1 of serving cell handover.

[0021] Figure 7 This is a diagram representing Example 2 of a serving cell handover.

[0022] Figure 8 This is a diagram representing example 3 of a serving cell handover.

[0023] Figure 9 This is a graph showing the timeline of L1L2-triggered mobility (LTM).

[0024] Figure 10 This is a diagram representing a RACH (PDCCH ordered RACH) based on PDCCH indications used for serving cells, with random access response (RAR) monitoring.

[0025] Figure 11 This is a diagram representing a RACH (PDCCH ordered RACH) based on PDCCH indications used for candidate cells without Random Access Response (RAR) monitoring.

[0026] Figure 12 This is a diagram illustrating an example of TA measurement based on the UE.

[0027] Figure 13 This is a diagram showing an example of PRACH transmissions for each candidate cell.

[0028] Figure 14 This is a diagram illustrating an example of the PDCCH command in this disclosure.

[0029] Figure 15 This is a diagram illustrating an example of the schematic structure of a wireless communication system according to one embodiment.

[0030] Figure 16 This is a diagram illustrating an example of the structure of a base station according to one embodiment.

[0031] Figure 17 This is a diagram illustrating an example of the structure of a user terminal according to one embodiment.

[0032] Figure 18 This is a diagram illustrating an example of the hardware structure of a base station and a user terminal according to one embodiment.

[0033] Figure 19 This is a diagram illustrating an example of a vehicle according to one embodiment. Detailed Implementation

[0034] (TCI, Spatial Relations, QCL)

[0035] 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).

[0036] 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.

[0037] 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.

[0038] QCL is an indicator that represents the statistical properties of a signal / channel. For example, it can also mean that, given a QCL relationship between a signal / channel and other signals / channels, it can be assumed that at least one of the following is the same (QCL): Doppler shift, Doppler spread, average delay, delay spread, and spatial parameter (e.g., spatial Rx parameter).

[0039] 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).

[0040] 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:

[0041] QCL Type A (QCL-A): Doppler shift, Doppler spread, average delay, and delay spread.

[0042] QCL Type B (QCL-B): Doppler shift and Doppler extension

[0043] QCL Type C (QCL-C): Doppler shift and average delay

[0044] QCL Type D (QCL-D): Space Reception Parameters.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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))).

[0050] 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).

[0051] 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.

[0052] 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 this RS can also be called the QCL source of QCL type X in TCI state.

[0053] (L1 / L2 inter-cell mobility)

[0054] 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.

[0055] <Scenario 1>

[0056] 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.

[0057] (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.

[0058] (2) The UE performs beam measurement for the TRP corresponding to different PCIs and reports the beam measurement results to the serving cell.

[0059] (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.

[0060] (4) The UE uses the dedicated channel on the TRP corresponding to different PCIs for transmission and reception.

[0061] (5) In the case of multiple TRPs, the UE needs to always cover the serving cell. As with previous systems, the UE needs to use common channels from the serving cell (Broadcast Control Channel (BCCH), Paging Channel (PCH)), etc.

[0062] 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.

[0063] Figure 1A This diagram illustrates an example of UE movement in Rel.17. Imagine the UE moving from PCI#1 cell (serving cell) to PCI#3 cell (additional cell) (overlapping with the serving cell). In this scenario, L1 / L2-based handover to the serving cell is not supported in Rel.17.

[0064] An additional cell is a cell with an additional PCI that differs 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. If the UE moves outside the coverage area of ​​the serving cell, a handover (also known as L3 mobility) is required.

[0065] <Scenario 2>

[0066] 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. Handover creates periods where data communication is impossible due to the need for RRC reconnection, etc. Therefore, by applying L1 / L2 inter-cell mobility that does not require handover, data communication can continue even during serving cell changes. Scenario 2 can also be applied, for example, in Rel. 18. In Scenario 2, for example, the following process is performed.

[0067] (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.

[0068] (2) The UE performs beam measurements for cells using different PCIs and reports the measurement results to the serving cell.

[0069] (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 is also possible to perform prior settings related to the serving cell change. This setting can be performed either together with the setting in (1) or separately.

[0070] (4)Based on the above report, the TCI states of cells with different PCIs can also be activated through L1 / L2 signaling according to the change of the serving cell. The activation of the TCI state and the change of the serving cell can also be performed separately.

[0071] (5)The UE changes the serving cell (the assumption of the serving cell) and starts receiving / sending using the UE-specific channels and TCI states that are pre-set.

[0072] That is, in scenario 2, the serving cell (the assumption of the serving cell in the UE) is updated through L1 / L2 signaling. Scenario 2 can also be applied in Rel.18.

[0073] Figure 1B It is a diagram showing an example of the movement of the UE in Rel.18. In Rel.18, the serving cell is switched through L1 / L2 (e.g., DCI / MAC CE). The UE can receive / send UE-specific channels / public channels between the new serving cell (or, the target serving cell). The UE can also get out of the coverage area of the current serving cell (e.g., Current serving cell).

[0074] <L1L2-triggered mobility (LTM) process>

[0075] Figure 2 It is a diagram showing an example of the LTM process. In addition, L1 / L2 inter-cell mobility and L1L2-triggered mobility (LTM) can also be rewritten with each other. In addition, Figure 2 the process is the process corresponding to the above scenario 2. Hereinafter, Figure 2 each process of

[0076] 1: After the UE is connected to RRC, it sends a MeasurementReport message to the base station (gNB). The gNB decides to use LTM based on the MeasurementReport and starts preparing candidate cells.

[0077] 2: The gNB sends a RRCReconfiguration message containing the LTM candidate cell settings of one or more candidate cells to the UE.

[0078] 3: The UE saves the received LTM candidate cell settings and sends an RRCReconfigurationComplete message to the gNB.

[0079] 4a / 4b: Before receiving the cell handover command, the UE performs DL / UL synchronization with the candidate cell to obtain timing advance (TA).

[0080] 5: The UE performs L1 measurements on the selected candidate cells and sends a low-layer (physical layer, L1) measurement report to the gNB. Alternatively, the UE can also send a measurement report to the gNB before synchronizing with the UL of the candidate cells.

[0081] 6: The gNB decides to execute the cell handover to the target cell and sends a MAC CE containing the candidate configuration index of the target cell to the UE, triggering the cell handover. Thus, the UE's cell configuration is switched to the target cell's configuration.

[0082] 7. When a random access procedure is required during cell handover, the UE performs the random access procedure towards the target cell. Alternatively, the UE can also perform the random access procedure based on a RACH procedure request from the gNB.

[0083] 8: The UE notifies the gNB that the cell handover to the target cell has been completed normally.

[0084] Alternatively, the UE can execute steps 4 to 8 multiple times in preparation for the next LTM cell handover, based on the LTM candidate cell settings received in step 2.

[0085] <Reduced Interruption Time>

[0086] In Rel.18 L1 / L2 inter-cell mobility (e.g., scenario 2 above), the UE can reduce the time without data transmission (interruption time). When applying Rel.18 LTM, compared to the method of handover based on L3 measurement results (L3 handover), the time without data transmission (interruption time) can be reduced. The specific processing for each is explained below.

[0087] Figure 3This diagram illustrates an example comparing L3 handover with LTM in Rel.18. In the L3 handover scenario, firstly, the UE performs L3 measurements and decides to handover based on the results. Then, the UE and the current serving cell perform RRC reset. Next, the UE performs DL synchronization and UL synchronization with the target serving cell. The UE performs L1 measurements / reports for the target serving cell and, upon receiving beam indication, sends initial UL data to the target serving cell. In this case, the UE does not send UL data during the period from the handover decision until the initial UL data is sent (an interruption).

[0088] In the LTM scenario of Rel.18, firstly, the UE performs L3 measurements. Then, the UE, the current serving cell, and the target serving cell perform RRC resets. Next, the UE performs DL synchronization with the target serving cell. Then, the UE performs L1 measurements / reports for both the current and target serving cells and performs UL synchronization. Then, the current serving cell sends an L1 / L2-based (DCI / MAC CE) cell handover command (including beam indication) to the UE. Finally, the UE sends the initial UL data to the target serving cell. In this case, the period from the receipt of the cell handover command to the transmission of this initial UL data is the UL transmission interruption time, but this interruption time is shorter compared to the L3 handover scenario.

[0089] (Setting up multiple candidate cells)

[0090] Figure 4 This 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).

[0091] Regarding the setting of the candidate cell (candidate cell) in the case of changing the serving cell, consider options 1 and 2 as follows.

[0092] <Option 1>

[0093] As with inter-cell mobility in Rel.17, the information in the 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.

[0094] For example, in Rel.17 inter-cell mobility, "mimoParam-r17" is appended under ServingCellConfig to add PCI configuration information. mimoParam-r17 can 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), the same settings as the serving cell can be applied, except for some information.

[0095] <Option 2>

[0096] 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.

[0097] 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) operation.

[0098] Figure 5A This is a diagram representing the first example of option 2 for candidate cell settings. Figure 5A In the example, the common candidate cell pool used for cell handover in the MCG / SCG is applied to the candidate cells. That is, regardless of the frequency band, the candidate cells are treated as a pool (group).

[0099] Figure 5B This is a diagram representing the second example of option 2 for candidate cell settings. Figure 5BIn 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.

[0100] (Signaling used for service cell change instructions)

[0101] This section describes the implicit or explicit signaling used for serving cell change indications.

[0102] [Method 1]

[0103] In Method 1, the implicit signaling used for service cell change indication is described.

[0104] [[Option 1-1]]

[0105] When a specific Control Resource Set (CORESET) (e.g., at least one of CORESET#0, CH5Type0-CSS, or CH6 / CH7 / CH8 CSS) is indicated (activated) via MAC CE along with one or more TCI states associated with a cell having a different PCI from the serving cell (for a specific CORESET, when one or more TCI states associated with a cell having a different PCI from the serving cell are 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.

[0106] 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.

[0107] [[Options 1-2]]

[0108] 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 will be changed to another cell (cell x). That is, this association can also implicitly indicate that the serving cell will be changed to another cell.

[0109] 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.

[0110] [[Options 1-3]]

[0111] When MAC CE activates / deactivates a unified TCI state (e.g., corresponding to the unified TCI framework in Rel.17), and all activated unified TCI states are associated with the same cell x with different PCIs, the UE can also determine to change the serving cell to another cell (cell x). That is, this association can also implicitly indicate changing the serving cell to another cell.

[0112] [Method 2]

[0113] In Method 2, the explicit signaling used for serving cell change indication is described. Method 2 is, for example, applied to Scenario 2 described above.

[0114] [[Option 2-1]]

[0115] The following is an example of a serving cell change instruction. Additionally, the activation / deactivation of a non-serving cell, 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 can also be mutually modified.

[0116] The UE can also receive a new MAC CE for activating / deactivating a non-serving cell and containing at least one of the fields (information) corresponding to the non-serving cell as shown in (1) to (3) below. Upon receiving this MAC CE, the UE can also determine that the serving cell has been changed to another cell (non-serving cell). Furthermore, the UE can also control the transmission and reception of DL / UL signals with the non-serving cell based on this information. In addition, there can 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.

[0117] (1) Service cell ID.

[0118] (2) BWP ID.

[0119] (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).

[0120] As an example of (3), any of (3-1) to (3-5) can also be applied.

[0121] (3-1) PCI (PCI that is used directly). For example, 10 bits are used.

[0122] (3-2) Recreated index (new ID) for non-serving cells. The new ID can also be associated with a portion of the PCI and is only assigned to the serving and non-serving cells that the UE can utilize. The new ID reduces the number of bits compared to the PCI.

[0123] (3-3) CSI report setting ID (CSI-ReportConfigId) (the case where CSI-ReportConfig corresponds to one or more non-serving cells).

[0124] (3-4) CSI Resource Configuration ID (CSI-ResourceConfigId) (CSI-ResourceConfigId corresponds to one or more non-serving cells).

[0125] (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 of three non-serving cells, it is set to "010".

[0126] 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, enabling the identification of the DL beam monitored by the UE 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).

[0127] [[Option 2-2]]

[0128] 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.

[0129] [[Options 2-3]]

[0130] 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.

[0131] 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.

[0132] [Serving Cell Handover Example 1]

[0133] Figure 6 This diagram illustrates Example 1 of serving cell handover. For example, in the serving cell SpCell#0 of the MCG / SCG, if the serving cell is instructed to be changed to candidate cell#0-2 via L1 / L2 signaling, 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 the serving cell is instructed to be changed to candidate cell#2-1 via L1 / L2 signaling, candidate cell#2-1 becomes the new serving cell SCell#2.

[0134] [Serving Cell Handover Example 2]

[0135] The RRC / MAC CE can also set global candidate cell IDs (cell#3,...,8) for each cell group, each band, each FR, and each UE. The UE can also be instructed to hand over the serving cell through this global candidate cell ID.

[0136] Figure 7 This is a diagram illustrating example 2 of a serving cell handover. (Compared to...) Figure 5A Similarly, a pool of multiple candidate cells can be configured, and the serving cell can be switched to any (activated) candidate cell within the pool via L1 / L2 signaling. In this case, the configured candidate cell can become either a SpCell or an SCell based on L1 / L2 signaling.

[0137] The UE can also receive an indication of a change in serving cell (from cell #2-1 to candidate cell #4) via MAC CE / DCI. Then, the indicated candidate cell #4 becomes the SpCell of the new cell group (MCG / SCG).

[0138] [Serving Cell Handover Example 3]

[0139] The RRC / MAC CE can also configure cell groups. The UE can also perform serving cell handover based on cell group handover.

[0140] Figure 8 This diagram illustrates Example 3 of serving cell handover. The UE receives an indication of a change in the cell group with the serving cell (a change to candidate cell group #1) via the MAC CE / DCI. Then, the cells included in the indicated candidate cell group #1 become the new serving cells (SpCell, SCell). For example, candidate cells #0, #1, and #2 included in the indicated candidate cell group #1 become the new SpCell#0, SCell#1, and SCell#2. That is, the serving cell group is switched.

[0141] (Timeline of L1L2-triggered mobility (LTM))

[0142] Figure 9 This is a graph representing the timeline of L1L2-triggered mobility (LTM). LTM and L1 / L2 inter-cell mobility can also be rewritten.

[0143] During UE reconfiguration, the UE receives candidate cell configurations from the NW. UE reconfiguration includes T... RRC T proccesing1 / T proccesing2 T RRC (For example, a maximum of 10ms) is the processing time used for RRC reconfiguration (RRC Reconfiguration) carrying candidate cell settings (candidate configurations). proccesing1 / T proccesing2 (For example, a maximum of 20ms for the same FR and a maximum of 40ms for different FRs) refers to the time allotted for UE processing before and after the cell handover command. This time may include L2 / 3 reconfiguration, RF retuning, baseband retuning, and, if necessary, security updates.

[0144] 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.

[0145] 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.

[0146] UL synchronization includes T IU T RAR T cmd T IU (For example, 15ms) is the indeterminate interruption time when an initial PRACH opportunity (occasion) is obtained in a new cell. T RAR (For example, 4ms) is the RAR latency. T cmd (For example, a maximum of 5ms) is the processing time for L1 / L2 commands (HARQ and paging).

[0147] 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.

[0148] (Pre-scheduled group)

[0149] 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.

[0150] 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.).

[0151] The UE can also apply timing advance (multiple timing advance) to control the timing of UL transmission according to each pre-set Timing Advance Group (TAG).

[0152] When applying multiple timing advances, Timing Advance Groups (TAGs) are supported, categorized by transmission timing. The UE can also be designed to control the UL transmission timing in each TAG by applying the same TA offset (or TA value) to each TAG. That is, the TA offset can also be set independently for each TAG.

[0153] In the case of multiple timing advances, by having the UE independently adjust the transmission timing of the cell belonging to each TAG, the uplink signal reception timing from the UE can be matched in the radio base station even when multiple cells are used.

[0154] 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).

[0155] Furthermore, it is envisioned that in future wireless communication systems, during 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 given cell (or CC) (e.g., multiple TRPs with different PCIs). Alternatively, it is also envisioned that different TRPs corresponding to a given cell will share a common TAG.

[0156] <TA Adjustment Based on Source Cell>

[0157] Figure 10 This diagram illustrates an example of RACH (PDCCH-ordered RACH) based on PDCCH commands, monitored using RAR. Furthermore, in this disclosure, source cell and source cell group can be interchanged. Additionally, candidate cell and candidate cell group can also be interchanged.

[0158] The source cell can also send information related to the configuration of candidate cells (e.g., candidate cell configuration information) to the UE. Furthermore, the source cell can also send PDCCH commands (e.g., DCI format 1_0) used in PRACH triggering to the UE. Candidate cells (e.g., a candidate cell) / Random Access Hour (RO) that can be indicated as the target of PRACH triggering / transmission can also be identified via PDCCH commands (or DCI). To obtain a Timing Advance Group (TAG) / Timing Advance (TA), the UE sends PRACH during the RACH process to the candidate cell based on PDCCH commands.

[0159] Next, the source cell sends a Responding Message (RAR) to the UE for the PRACH. The RAR may also contain information related to the TA (e.g., a TA indication). The RAR (e.g., the PDSCH containing the RAR / the PDCCH that schedules the PDSCH) may also be monitored within a specific search space (e.g., the Common Search Space (CSS)) of a specific cell (e.g., SpCell) in the current serving cell (only within the Distributed Unit (DU)). Then, in the source cell, TA adjustments (e.g., TA maintenance) are performed.

[0160] Next, the source cell sends a cell handover command to the UE. Additionally, the TA information is moved from the source cell to / notified to the target cell. The UE can also control UL transmission based on the acquired TA after the cell handover. For example, if UL synchronization of all candidate cells is not completed after the initial cell handover, the UE can use the initial TA to perform the initial UL transmission.

[0161] Figure 11 This is a diagram illustrating an example of RACH based on PDCCH commands (PDCCH-ordered RACH) without using RAR monitoring. For Figure 11 This is only to explain the relationship with Figure 10 The differences.

[0162] exist Figure 11 In some examples, the PDCCH command used in PRAH triggering can indicate one or more candidate cells (e.g., multiple candidate cells) / random access opportunities as the target of PRACH triggering / transmission. For multiple TAG / TA acquisitions, the UE can also send PRACH during the RACH process to candidate cells based on the PDCCH command. The source cell does not send a PRACH acknowledgment signal (e.g., RAR). The source cell can also use cell handover commands to indicate TA-related information to the UE (e.g., TA indication).

[0163] In this disclosure, RACH without RAR and RACH without RAR monitoring (e.g., RACH without RAR monitoring) can also be rewritten to each other. RACH can also be rewritten as PRACH transmission triggered by a PDCCH command. RACH / PRACH transmission without RAR monitoring can also be rewritten as RACH / PRACH transmission that does not require RAR monitoring, or RACH / PRACH transmission that does not request RAR monitoring.

[0164] <UE-based TA calculation / measurement>

[0165] Figure 12 This diagram illustrates an example of TA measurement based on the UE. The source cell can also send information to the UE regarding the setting of candidate cells (e.g., candidate cell setting information). The UE then determines the candidate cells to be set in the TA measurement. The UE then receives signaling (e.g., MAC CE / DCI) to trigger / grant the UE-based TA measurement. The UE receives DL signals from the source cell and candidate cells at different timings.

[0166] Next, the UE performs TA calculation / measurement. During TA calculation / measurement, the UE can also calculate / measure the differential timing (DL) between the reference cell (e.g., the source cell) and the candidate cell. The UE can also autonomously perform TA calculation / measurement after RRC is configured or after receiving specific signaling. The UE can also perform TA calculation / measurement for cells indicated via higher-layer signaling / physical layer signaling. Additionally, in asynchronous scenarios between the reference cell and the candidate cell, the UE can use the offset parameter set in the RRC configuration. The UE can also stop TA calculation / measurement under certain conditions.

[0167] Next, the source cell can also send a cell handover command to the UE. Furthermore, TA information can be moved from the source cell to / notified to the target cell. The UE can also control UL transmission based on the calculated TA after the cell handover. For example, if UL synchronization of all candidate cells is not completed after the initial cell handover, the UE can use the initial TA to perform the initial UL transmission.

[0168] (analyze)

[0169] Figure 13 This is a diagram illustrating examples of PRACH transmissions for each candidate cell. (As shown in...) Figure 10 , 11As explained, after receiving information related to the setting of candidate cells and a PDCCH command, the UE sends a PRACH to the candidate cells. In this PDCCH command, multiple candidate cells are set. In this case, consider the UE sending PRACH to each of the set candidate cells. For example, the UE sends PRACH to each of cells #1, #2, and #3. Alternatively, the UE can... Figure 10 In that case, receiving RAR after PRACH can also be done as follows: Figure 11 In that case, RAR will not be received after PRACH. Whether or not RAR reception is possible can also be preset to the UE via RRC signaling.

[0170] However, it remains unclear how to transmit PRACH messages for each candidate cell when the UE is configured / indicated with multiple candidate cells. Improper implementation of PRACH transmission for each candidate cell could lead to concerns about degraded communication quality with the candidate cells after cell handover.

[0171] Therefore, the inventors of this invention studied methods for appropriately performing PRACH transmissions for each candidate cell and conceived of an example of this embodiment.

[0172] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, the following embodiments / methods (e.g., various situations) can be used individually or in combination of at least two.

[0173] (Various rewrites, etc.)

[0174] 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".

[0175] In this disclosure, terms such as notification, activation, deactivation, indication (or indication), selection, configuration, update, and determination can be overridden. Similarly, terms such as support, control, ability to control, operation, and ability to operate can also be overridden.

[0176] In this disclosure, Radio Resource Control (RRC), RRC parameters, RRC messages, higher-level parameters, fields, Information Elements (IE), settings, etc., can also be modified interchangeably. In this disclosure, Medium Access Control (MAC) control elements (CE), update commands, activation / deactivation commands, etc., can also be modified interchangeably.

[0177] 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.)

[0178] 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).

[0179] In this disclosure, physical layer signaling may also be, for example, downlink control information (DCI), uplink control information (UCI), etc.

[0180] In this disclosure, the terms cell, PCI, serving cell, SpCell, source serving cell, CC, BWP, BWP within CC, and band domain can be mutually modified. In this disclosure, additional cells, other cells, non-serving cells, cells with different PCIs, candidate cells, candidate serving cells, cells with PCIs different from the current serving cell, other serving cells, target cells, target serving cells, and neighboring cells can also be mutually modified. In this disclosure, handover, change, and update can also be mutually modified. The serving cell can also be modified to the serving cell before or after the handover. LTM applications, cell applications, and cell handover can also be mutually modified. LTM applications, beam applications, and beam switching can also be mutually modified.

[0181] In this disclosure, RACH resources, RA resources, PRACH preamble, timing, RACH timing (RO), PRACH timing, repetition resources, repetition setting resources, resources set for RO / repetition, time instances and frequency instances, time resources and frequency resources, RO / preamble resources, repetition, PRACH resources, time / frequency resources used for PRACH, preamble setting / index, mask setting / index, and PRACH setting can also be overridden.

[0182] In this disclosure, candidate cells and candidate cell groups can be interchanged. The candidate cells in this disclosure can also be candidate cells indicated in the PDCCH command. The PDCCH command and DCI (e.g., DCI format 1_0) can also be interchanged. In this disclosure, RO, RO index, and RO# can also be interchanged.

[0183] (Wireless communication method)

[0184] In this disclosure, it is also permissible if the UE receives a PDCCH command (DCI) containing information (indicators / parameters) separated for each candidate cell / PRACH in relation to the PRACH transmission for each candidate cell. Figure 14 Based on the PDCCH command, the system controls the PRACH transmission for each of the multiple candidate cells. Alternatively, similar to contention-based random access, at least one indication (parameter) can be selected by the UE. The candidate cells in this embodiment can also be candidate cells set / indicated in the PDCCH command. Candidate cells can also be pre-set / indicated via higher-layer signaling (e.g., RRC / MAC CE).

[0185] Alternatively, if at least one of the indications corresponding to multiple candidate cells / PRACHs is common, only one of that common indications may be included in the PDCCH command. This can suppress the increase in the number of bits in the PDCCH.

[0186] <Implementation Method 1.1>

[0187] Implementation method 1.1 (options 1-7) may also be based on the following premise: at least a portion of the information in the PDCCH command related to the PRACH transmission for each candidate cell (e.g., multiple candidate cells) is the same in multiple candidate cells / PRACH transmissions. The information related to PRACH transmission may, for example, include the random access preamble index, SS / PBCH index, PRACH mask index, and information indicating whether the PRACH is an initial transmission or a retransmission.

[0188] Option 1

[0189] The UE does not assume the above premise (that at least part of the information related to the PRACH for each candidate cell is the same in the PDCCH command).

[0190] Option 2

[0191] The UE transmits the same PRACH to multiple candidate cells. This option can also be applied if FR1 is applied, or if at least one of the SS / PBCH index, random access preamble index, or PRACH mask index in the PDCCH command is the same across the PRACH transmissions in each candidate cell. This is because it is possible to transmit a single PRACH to multiple cells.

[0192] In option 2, the range of PRACH that the UE selects (sends, applies) can also be any of the following options 2-1 to 2-3.

[0193] Option 2-1: Same (one) candidate cell / component carrier (CC) / frequency / candidate cell group.

[0194] Option 2-2: The same (one) band field.

[0195] Option 2-3: The same (one) list of CCs (if set via RRC).

[0196] If the UE is able to send PRACH to each candidate cell simultaneously, the following options 3 to 5 can also be applied.

[0197] Option 3

[0198] Alternatively, if the number of candidate cells indicated in the PDCCH command is less than the number of simultaneous PRACH transmissions (maximum number of simultaneous transmissions) indicated in the UE capability information sent by the UE, the UE may simultaneously transmit PRACH to each candidate cell.

[0199] Alternatively, if the number of candidate cells indicated in the PDCCH command is greater than the number of simultaneous PRACH transmissions (maximum number of simultaneous transmissions) indicated in the UE capability information sent by the UE, then option 4 or 5 below shall be applied.

[0200] Option 4

[0201] When the RACH timing (RO) of the PRACH of each candidate cell is different, the UE transmits the PRACH of each candidate cell in the corresponding RO. For example, it is also possible that the UE transmits the PRACH of each candidate cell simultaneously if at least one RO of the PRACH of each candidate cell is different, and the number of PRACHs in the same RO is less than the number of simultaneous PRACH transmissions (maximum number of simultaneous transmissions) indicated in the UE capability information.

[0202] Option 5

[0203] The UE can also prioritize transmitting PRACH corresponding to a specific candidate cell, either indicated / set via DCI / MAC CE / RRC, predefined in the specification, or determined based on the UE's implementation. That is, the UE can also determine which PRACH (the candidate cell to which the transmission destination is) to transmit based on the priority of the candidate cell / PRACH, which has been set / indicated / defined. Priorities can also be set / indicated / defined for each candidate cell group.

[0204] Prioritization for UL transmission, used to determine transmission power when UL is transmitted simultaneously, can also be applied to PRACH transmission for candidate cells.

[0205] Option 5-1: Prioritize sending PRACH to candidate cells in descending order of the values ​​of parameters related to the corresponding candidate cell / PRACH transmission (e.g., random access preamble index, SS / PBCH index, PRACH mask index, candidate cell ID, or candidate cell group ID).

[0206] Option 5-2: Prioritize sending PRACH to candidate cells in ascending order of the values ​​of parameters related to the corresponding candidate cell / PRACH transmission (e.g., random access preamble index, SS / PBCH index, PRACH mask index, or candidate cell ID).

[0207] Option 5-3: The UE prioritizes sending the initial PRACH for the candidate cell (not a retransmission).

[0208] Option 5-4: The UE prioritizes sending retransmitted PRACH messages for candidate cells.

[0209] Option 5

[0210] Option 5'-1: The UE prioritizes sending PRACHs for the candidate cell that is the current Scell ​​(the active Scell).

[0211] Option 5'-2: The UE prioritizes sending PRACH messages from candidate cells that use the same frequency as the serving cell.

[0212] Option 5'-3: The UE prioritizes sending PRACH messages from candidate cells that use frequencies different from the serving cell.

[0213] Option 5'-4: The UE prioritizes sending PRACH messages for candidate cells whose TCI status is activated.

[0214] Alternatively, if the UE can only send PRACH to one candidate cell at the same time (but cannot send PRACH to multiple candidate cells at the same time), then the following options 6 and 7 can be applied.

[0215] Option 6

[0216] When the RACH timing (RO) of the PRACH of each candidate cell is different, the UE sends the PRACH of each candidate cell in the corresponding RO.

[0217] Option 7

[0218] The UE may also prioritize transmitting PRACHs corresponding to specific candidate cells that are indicated / set via DCI / MAC CE / RRC or predefined in the specification. That is, the UE may also decide which PRACH (the candidate cell to which the transmission destination is) to transmit based on the priority of the candidate cells / PRACHs that have been set / indicated / defined. Priorities can also be set / indicated / defined for each candidate cell group.

[0219] When the UE can only transmit PRACH to one candidate cell simultaneously (but cannot transmit PRACH to multiple candidate cells simultaneously), options 5-1 to 5-4 and 5'-1 to 5'-4 can also be applied. Furthermore, the priority for UL transmission used to determine the transmission power when transmitting UL simultaneously can also be applied to PRACH transmission to candidate cells.

[0220] <Implementation Method 1.2>

[0221] Implementation method 1.2 (options 8-13) may also be based on the following premise: all information related to PRACH transmission in the PDCCH command for each candidate cell (e.g., multiple candidate cells) is different for each candidate cell / PRACH. The information related to PRACH transmission may include, for example, a random access preamble index, an SS / PBCH index, a PRACH mask index, and information indicating whether the PRACH is an initial transmission or a retransmission.

[0222] Option 8

[0223] The UE does not assume the above premise (that all the information in the PDCCH command related to the PRACH transmission for each candidate cell is different).

[0224] Alternatively, if the UE is able to send PRACH to each candidate cell simultaneously, the following options 9-11 can be applied.

[0225] Option 9

[0226] Alternatively, if the number of candidate cells indicated in the PDCCH command is less than the number of simultaneous PRACH transmissions (maximum number of simultaneous transmissions) indicated in the UE capability information sent by the UE, the UE may simultaneously transmit PRACH to each candidate cell.

[0227] Alternatively, if the number of candidate cells indicated in the PDCCH command is greater than the number of simultaneous PRACH transmissions (maximum number of simultaneous transmissions) shown in the UE capability information sent by the UE, then option 10 or 11 can be applied.

[0228] Option 10

[0229] The UE transmits the PRACH of each candidate cell in its corresponding RO. In addition, option 10 is based on the premise that all information in the PDCCH command related to the PRACH transmission of each candidate cell is different, therefore, the RO of each candidate cell is also different.

[0230] Option 11

[0231] The UE can also prioritize transmitting PRACH corresponding to specific candidate cells, either indicated / set via DCI / MAC CE / RRC or predefined in the specification / UE implementation. That is, the UE can also determine which PRACH (the candidate cell to which the transmission destination is) to transmit based on the priority of the candidate cells / PRACHs that have been set / indicated / defined. Priorities can also be set / indicated / defined for each candidate cell group.

[0232] The priority for UL transmission, used to determine the transmission power when UL is transmitted simultaneously, can also be applied to PRACH transmission for candidate cells.

[0233] As a specific example of option 11, options 5-1 to 5-4 can also be applied in the same way. In addition, options 5' (5'-1 to 5'-4) can also be applied in the same way.

[0234] Alternatively, when the UE can only send PRACH to one candidate cell at the same time (when it cannot send PRACH to multiple candidate cells at the same time), options 12 and 13 above can be applied.

[0235] Option 12

[0236] The UE transmits the PRACH of each candidate cell in its corresponding RO. In addition, option 10 assumes that all information in the PDCCH command related to the PRACH transmission of each candidate cell is different, so the RO of each candidate cell is also different.

[0237] Option 13

[0238] The UE may also prioritize transmitting PRACHs corresponding to specific candidate cells that are indicated / set via DCI / MAC CE / RRC or predefined in the specification. That is, the UE may also decide which PRACH (the candidate cell to which the transmission destination is) to transmit based on the priority of the candidate cells / PRACHs that have been set / indicated / defined. Priorities can also be set / indicated / defined for each candidate cell group.

[0239] When the UE can only transmit PRACH to one candidate cell simultaneously (but cannot transmit PRACH to multiple candidate cells simultaneously), options 5-1 to 5-4 and 5'-1 to 5'-4 can also be applied. Furthermore, the priority for UL transmission used to determine the transmission power when transmitting UL simultaneously can also be applied to PRACH transmission to candidate cells.

[0240] <Changes>

[0241] The following variations, used to illustrate the changes in this disclosure, may also be combined with at least one of Embodiments 1.1 and 1.2.

[0242] The options in Implementation 1.1 (Options 1-7) can also be used as options in Implementation 1.2. Similarly, the options in Implementation 1.2 (Options 8-13) can also be used as options in Implementation 1.1.

[0243] Implementation 1.1 is described under the premise that at least a portion of the information in the PDCCH command related to the PRACH transmission of each candidate cell is the same, but the options (options 1 to 7) can also be applied without applying this premise. Furthermore, Implementation 1.2 is described under the premise that all the information in the PDCCH command related to the PRACH transmission of each candidate cell is different, but the options (options 8 to 13) can also be applied without applying this premise.

[0244] In this disclosure, it is described under the premise that a PDCCH command contains separate indications (parameters) corresponding to multiple candidate cells / PRACHs. However, it is also possible for a PDCCH command to contain an indication (parameter) corresponding to a candidate cell / PRACH and for the PDCCH command to be sent multiple times. Alternatively, it is possible for a PDCCH command to contain an indication (parameter) corresponding to more than one candidate cell / PRACH and for the PDCCH command to be sent multiple times.

[0245] In this disclosure, PRACH repetition can also be applied. For example, the UE can perform PRACH repetition for each candidate cell. The UE can also determine the number of PRACH repetitions for each candidate cell based on a priority indicated / set via DCI / MAC CE / RRC or predefined in the specification. The priority can also be the same as the priority in options 5 or 11 above.

[0246] The UE can either repeatedly transmit PRACH messages for each candidate cell, or it can transmit PRACH messages for each candidate cell one at a time and then transmit PRACH messages for the next candidate cell. That is, for example, if there are candidate cells #1 and #2, and three repeated transmissions are performed, the UE can transmit PRACH messages in the order of candidate cells #1, #1, #1, #2, #2, #2, or in the order of candidate cells #1, #2, #1, #2, #1, #2.

[0247] Alternatively, if the UE is capable of simultaneously transmitting PRACH to each candidate cell, it can transmit PRACH simultaneously for each candidate cell group. For example, if the maximum number of candidate cells within a candidate cell group is less than the number of simultaneous PRACH transmissions (maximum simultaneous transmissions) shown in the UE capability information transmitted by the UE, the UE can transmit PRACH simultaneously to the candidate cells within the candidate cell group. Alternatively, if the maximum number of candidate cells within a candidate cell group is greater than the number of simultaneous PRACH transmissions (maximum simultaneous transmissions) shown in the UE capability information transmitted by the UE, the UE can apply any one of the above options 4, 5, 5', 10, and 11.

[0248] <Supplement>

[0249] [Information notification to UE]

[0250] 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.

[0251] 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) that is not specified in the existing standard in the MAC subheader.

[0252] 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.

[0253] Furthermore, the notification of any information to the UE in the above embodiments can also be carried out periodically, semi-persistently, or non-periodically.

[0254] [Notification from UE]

[0255] 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.

[0256] In the case where the above notification is made 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.

[0257] In cases where the above notification is sent via UCI, the above notification may also be sent using PUCCH or PUSCH.

[0258] Furthermore, the notification of any information from the UE in the above embodiments can also be carried out periodically, semi-persistently, or non-periodically.

[0259] [Regarding the application of each implementation method]

[0260] 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.

[0261] At least one of the above implementation methods can also be applied only to UEs that have reported a specific UE capability or support that specific UE capability. In addition, "support" and "whether to support" can be rewritten interchangeably.

[0262] This specific UE capability can also represent at least one of the following:

[0263] Supports specific processing / operation / control / information for at least one of the above embodiments;

[0264] PRACH simultaneous transmission count (maximum number of simultaneous transmissions);

[0265] The number of supported candidate cells;

[0266] The number of supported candidate cell groups.

[0267] Furthermore, the aforementioned specific UE capabilities can be applied across the entire frequency (commonly regardless of frequency), or per frequency (e.g., one or a combination of cells, bands, band combinations, BWPs, component carriers, etc.), or per frequency range (e.g., Frequency Range 1 (FR1), FR2, FR3, FR4, FR5, FR2-1, FR2-2), or per subcarrier spacing (SCS), or per feature set (FS) or per component carrier feature set (FSPC).

[0268] Furthermore, the aforementioned specific UE capabilities can be either the ability to apply across all duplex modes (commonly independent of duplex mode) or the capability for each duplex mode (e.g., Time Division Duplex (TDD) and Frequency Division Duplex (FDD)).

[0269] 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 performs the operations of the above-described embodiments) via higher-layer signaling / physical layer signaling. For example, this specific information may be information indicating LTM activation, arbitrary RRC parameters for a specific version (e.g., Rel.18 / 19), etc.

[0270] The UE may also apply operations such as Rel.15 / 16 / 17 if it does not support at least one of the specific UE capabilities mentioned above, or if the specific information mentioned above is not set.

[0271] (Postscript)

[0272] With respect to one embodiment of this disclosure, the following invention is noted.

[0273] [Postscript 1]

[0274] A terminal having:

[0275] The receiving unit receives Physical Downlink Control Channel (PDCCH) commands containing information related to the transmission of Physical Random Access Channel (PRACH) for multiple candidate cells; and

[0276] The control unit controls the transmission of the PRACH for each of the plurality of candidate cells.

[0277] [Appendix 2]

[0278] According to the terminal described in Appendix 1,

[0279] It also has a transmitting unit that transmits the same PRACH to the multiple candidate cells when at least a portion of the information in the PDCCH command is the same in multiple PRACH transmissions.

[0280] [Appendix 3]

[0281] According to the terminal described in Appendix 1 or Appendix 2,

[0282] It also has a transmission unit that, when the number of the plurality of candidate cells is less than the number of simultaneous transmissions of the PRACH shown in the capability information transmitted by the terminal, simultaneously transmits the PRACH to each candidate cell.

[0283] [Appendix 4]

[0284] According to any one of Annexes 1 to 3,

[0285] If the number of candidate cells is greater than the number of simultaneous PRACH transmissions shown in the capability information sent by the terminal, the control unit determines which PRACH to transmit based on the priority of the candidate cells or the PRACH.

[0286] (Wireless communication system)

[0287] 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.

[0288] Figure 15 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).

[0289] 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.

[0290] 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.

[0291] 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))).

[0292] 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.

[0293] 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).

[0294] 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 be equivalent to a frequency band higher than FR2.

[0295] 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.

[0296] 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.

[0297] 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.

[0298] 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.

[0299] User terminal 20 can also be at least one terminal that supports communication methods such as LTE, LTE-A, and 5G.

[0300] 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.

[0301] 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.

[0302] 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.

[0303] 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.

[0304] 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.

[0305] 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.

[0306] 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.

[0307] 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.

[0308] A search space can also correspond to one or more PDCCH candidates equivalent 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.

[0309] The PUCCH can also transmit at least one uplink control information (uplink control information (UCI)) that includes Channel State Information (CSI), delivery confirmation information (e.g., also known as Hybrid Automatic Repeat Request ACK Knowledge (HARQ-ACK), ACK / NACK, etc.), and a scheduling request (SR). The PRACH can also transmit random access preambles used for establishing a connection with the cell.

[0310] 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".

[0311] 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).

[0312] 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.

[0313] 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).

[0314] (Base station)

[0315] Figure 16This 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.

[0316] 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.

[0317] 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.

[0318] 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.

[0319] 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.

[0320] 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.

[0321] 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.

[0322] 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.

[0323] 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.

[0324] 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.

[0325] 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.

[0326] 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.

[0327] 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.

[0328] 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.

[0329] 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.

[0330] 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.

[0331] 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.

[0332] The transmitting and receiving unit 120 can also transmit Physical Downlink Control Channel (PDCCH) commands containing information related to the transmission of the Physical Random Access Channel (PRACH) for multiple candidate cells.

[0333] The control unit 110 can also control the reception of the PRACH for each of the plurality of candidate cells.

[0334] (User terminal)

[0335] Figure 17 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.

[0336] 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.

[0337] 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.

[0338] 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.

[0339] 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.

[0340] 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.

[0341] 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.

[0342] 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.

[0343] 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.

[0344] 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.

[0345] 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.

[0346] Furthermore, the decision to apply DFT processing can be based on the transform precoding settings. For a certain channel (e.g., PUSCH), if transform precoding is enabled, the transmit / receive unit 220 (transmit processing unit 2211) may perform DFT processing as the aforementioned transmission processing in order to transmit the channel using the DFT-s-OFDM waveform. Otherwise, the transmit / receive unit 220 (transmit processing unit 2211) may choose not to perform DFT processing as the aforementioned transmission processing.

[0347] 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.

[0348] 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.

[0349] 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.

[0350] 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.

[0351] 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.

[0352] 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.

[0353] The transmitting and receiving unit 220 can also receive Physical Downlink Control Channel (PDCCH) commands containing information related to the transmission of Physical Random Access Channel (PRACH) for multiple candidate cells.

[0354] The control unit 210 can also control the transmission of the PRACH for each of the plurality of candidate cells.

[0355] The transmitting and receiving unit 220 may also transmit the same PRACH to the multiple candidate cells if at least a portion of the information in the PDCCH command is the same in multiple PRACH transmissions.

[0356] The transmitting and receiving unit 220 may also transmit the PRACH to each candidate cell simultaneously when the number of the plurality of candidate cells is less than the number of simultaneous transmissions of the PRACH shown in the capability information transmitted by the terminal.

[0357] The control unit 210 may also determine the PRACH to be sent based on the priority of the candidate cells or the PRACH when the number of candidate cells is greater than the number of simultaneous PRACHs shown in the capability information sent by the terminal.

[0358] (Hardware structure)

[0359] 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.

[0360] 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.

[0361] 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 18 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.

[0362] 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.

[0363] 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.

[0364] 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.

[0365] 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.

[0366] 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.

[0367] 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.

[0368] 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 (CD-ROM)), digital multifunction disk, Blu-ray disc, removable disk, hard disk drive, smart card, flash memory device (e.g., a card, stick, key drive), stripe, database, server, or at least one other suitable storage medium. Storage device 1003 may also be referred to as an auxiliary storage device.

[0369] 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) can also be implemented by the communication device 1004. The transmit / receive unit 120 (220) can also be implemented by physically or logically separating the transmit unit 120a (220a) and the receive unit 120b (220b).

[0370] 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).

[0371] 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.

[0372] 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.

[0373] (Variation example)

[0374] 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.

[0375] 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).

[0376] 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.

[0377] 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.

[0378] 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.

[0379] 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.

[0380] 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.

[0381] 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.

[0382] 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.

[0383] 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.

[0384] 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.

[0385] 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.

[0386] 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.

[0387] 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.

[0388] 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.

[0389] 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.

[0390] 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.

[0391] 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.

[0392] 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".

[0393] 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.

[0394] 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.

[0395] 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.

[0396] 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.

[0397] 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.

[0398] 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.

[0399] 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.

[0400] 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).

[0401] 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).

[0402] 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).

[0403] 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.

[0404] 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.

[0405] 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).

[0406] 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.

[0407] 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 / symbol / 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.

[0408] 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.

[0409] 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.

[0410] 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.

[0411] 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.

[0412] 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.

[0413] Furthermore, the spatial relationship information identifier (ID) (TCI state ID) and the 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 relationship can also be interchanged.

[0414] 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.

[0415] 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.

[0416] In this disclosure, the situation in which the base station sends information to the terminal can also be modified to describe the situation in which the base station instructs the terminal to perform control / operation based on that information.

[0417] In this disclosure, the terms “Mobile Station (MS)”, “user terminal”, “user equipment (UE)”, and “terminal” are used interchangeably.

[0418] 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.

[0419] 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.

[0420] The term "mobile body" refers to a movable object whose speed is arbitrary, including situations where the body 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.

[0421] 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.

[0422] Figure 19 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.

[0423] 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.

[0424] 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).

[0425] 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.

[0426] The information service unit 59 consists of various devices for providing (outputting) various information such as driving information, traffic information, and entertainment information, including navigation systems, audio systems, speakers, displays, televisions, and radios, as well as one or more ECUs for controlling these devices. The information service unit 59 uses information obtained from external devices via communication modules 60 and the like to provide various information / services (e.g., multimedia information / multimedia services) to the occupants of the vehicle 40.

[0427] 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.

[0428] 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.

[0429] 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.

[0430] 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).

[0431] 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.

[0432] 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).

[0433] 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.

[0434] 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.

[0435] 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.

[0436] In this disclosure, actions 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., consider a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc., but not limited to these), or combinations thereof.

[0437] 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.

[0438] 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, a registered trademark), IEEE 802.16 (WiMAX, a registered trademark), IEEE 802.20, Ultra-Wideband (UWB), Bluetooth, systems utilizing other suitable wireless communication methods, and next-generation systems derived from, extended by, modified by, generated by, or specified based on these methods. Furthermore, multiple systems can be combined (e.g., LTE or LTE-A, or a combination with 5G, etc.) for application.

[0439] 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".

[0440] 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.

[0441] 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.

[0442] 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.

[0443] That is, "judgment (decision)" can also refer to situations in which certain actions are considered as making a "judgment (decision)". Furthermore, "judgment (decision)" can also be rewritten as "assuming", "expecting", "considering", etc. In this disclosure, "judgment (decision)" can also be rewritten interchangeably with the operations described above.

[0444] Furthermore, in this disclosure, "determine / determining" can also be interchanged with "assume / assuming," "expect / expecting," "consider / considering," etc. Additionally, in this disclosure, "not assuming..." can also be interchanged with "assuming not...".

[0445] In this disclosure, "expect" can also be interchanged with "be expected." For example, "expect(s) ..." ("..." can also be expressed using a "that" clause, an indefinite "to", etc.) can 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).

[0446] 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).

[0447] 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.”

[0448] 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.

[0449] 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."

[0450] 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.

[0451] 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.

[0452] 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 the prefix "the i-th" (where i is any integer), are not limited to the positive, comparative, and superlative degrees, and can be interchanged (for example, "highest" can also be interchanged with "the i-th highest").

[0453] In this disclosure, "of", "for", "regarding", "related to", "associated with", etc., can also be rewritten interchangeably.

[0454] In this disclosure, phrases such as "when A, B", "if A, then B", "B upon A", "in response to A", "based on A", "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 after or immediately before). 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.

[0455] In this disclosure, timing, moment, time, time instance, arbitrary time unit (e.g., time slot, sub-time slot, symbol, subframe), period, occasion, resource, etc., can also be overridden.

[0456] 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 physical downlink control channel commands (PDCCH commands) containing information related to physical random access channel (PRACH) transmission for multiple candidate cells; and The control unit controls the transmission of the PRACH for each of the plurality of candidate cells.

2. The terminal according to claim 1, wherein, It also has: A sending unit that, when at least a portion of the information in the PDCCH command is the same in multiple PRACH transmissions, sends the same PRACH to the multiple candidate cells.

3. The terminal according to claim 1, wherein, It also has: A transmitting unit that, when the number of candidate cells is less than the number of simultaneous PRACH transmissions shown in the capability information transmitted by the terminal, simultaneously transmits the PRACH to each candidate cell.

4. The terminal according to claim 1, wherein, If the number of candidate cells is greater than the number of simultaneous PRACH transmissions shown in the capability information sent by the terminal, the control unit determines which PRACH to transmit based on the priority of the candidate cells or the PRACH.

5. A wireless communication method, which is a wireless communication method for a terminal, comprising: The steps of receiving a physical downlink control channel command (PDCCH) containing information related to physical random access channel transmission (PRACH) for multiple candidate cells; and The steps for controlling the transmission of the PRACH for each of the plurality of candidate cells.

6. A base station, comprising: The transmitting unit transmits Physical Downlink Control Channel (PDCCH) commands containing information related to Physical Random Access Channel (PRACH) transmission for multiple candidate cells; and The control unit controls the reception of the PRACH for each of the plurality of candidate cells.

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