Method and apparatus relating to timing advance in wireless communication system

Abstract

According to an embodiment of the present disclosure, a method performed by a user equipment comprises the steps of: receiving configuration information related to a plurality of control resource sets (CORESETs); receiving configuration information related to a timing advance group (TAG); and releasing the configuration related to the uplink transmission based on expiration of the time alignment timer related to the TAG. The TAG comprises i) a first TAG related to the first CORESET pool index and ii) a second TAG related to the second CORESET pool index, the time alignment timers comprise i) a first time alignment timer related to the first TAG and ii) a second time alignment timer related to the second TAG, and configuration related to uplink transmission is released based on expiration of the first time alignment timer.

Description

Technical Field

[0001] The present disclosure relates to methods and apparatus related to timing advance in a wireless communication system. Background Art

[0002] A mobile communication system has been developed to provide voice services while ensuring user activities. Mobile communication systems have expanded their services from voice to data. The current rapid growth of data services is consuming resources, and users' demand for higher data rate services has led to a demand for more advanced mobile communication systems.

[0003] The requirements for the next generation of mobile communication systems must be able to meet the processing of explosive data services, the sharp increase in the transmission rate per user, the significant increase in the number of connected devices, and the support of very low end-to-end latency and high energy efficiency. To this end, a variety of technologies have been studied, such as dual connectivity, massive multiple-input multiple-output (MIMO), in-band full-duplex, non-orthogonal multiple access (NOMA), ultra-wideband support, and device networking.

[0004] In the existing LTE and NR standards, in the uplink timing advance configuration / indication, a single timing advance (TA) value is supported for a timing advance group (TAG) to which a specific cell or cell group belongs.

[0005] In an environment where there is a large difference in distance between the UE and different TRPs, multi-DCI-based multiple transmission and reception point (M-DCI-based M-TRP) operation can be performed. In this case, propagation delay differences, slot boundary differences, and inter-UE panel delay differences may occur between target TRPs for uplink transmission within a CC / BWP. In particular, this phenomenon may occur to a greater extent in non-ideal backhaul operations where no coordination is performed between TRPs.

[0006] As described above, in order to compensate for the timing differences or delays that occur between TRPs, it is necessary to determine the uplink timing differently for each TRP. To this end, an operation of connecting TAGs / TCI states corresponding to unified TCIs (e.g., joint TCI states, separate TCI states (DL TCI states or UL TCI states)) has been agreed upon. Summary of the invention

[0007] Technical issues

[0008] When using time alignment timers associated with multiple TAGs, uplink time alignment management operations may be ambiguous according to existing schemes. For example, an operation of releasing UL / DL configuration (e.g., a release operation of PUCCH / SRS and a clearing operation of DL assignment, UL grant, and PUSCH resources) is performed based on the expiration of a time alignment timer associated with a TAG (PTAG). At this time, it is unclear whether the operation is performed based on the expiration of any one of the multiple timers (e.g., i) the expiration of each timer, ii) the expiration of a specific timer among the multiple timers, or iii) the expiration of all timers).

[0009] Furthermore, since releasing all UL configurations (eg, PUCCH configurations) will disable HARQ-ACK transmission for DL ​​reception (from all serving cells), if this release operation is performed frequently, it will affect DL operations as well as UL operations.

[0010] The purpose of the present disclosure is to propose a method to resolve the ambiguity of operations related to the expiration of the time alignment timer in managing TRP-specific TAs and minimize the impact of such operations on UL / DL.

[0011] When the RSRP of the SSB corresponding to the SSB index indicated based on the DCI associated with the PDCCH order is less than or equal to the set threshold, the UE selects a random SSB (SSB index) and then sends a random access preamble based on the SSB index. Such an operation may not be efficient in obtaining / managing a TRP-specific TA. As an example, it may be assumed that the time alignment timer for a TA (e.g., the first TA) associated with TRP 1 (e.g., the first CORESET pool index) expires. Because the UE randomly selects any one of a plurality of SSB indexes, an SSB index associated with TRP 2 (or the DL transmission beam of TRP 2) may be selected. In this case, it may be difficult to obtain the TA for TRP 1, or an inaccurate TA may be obtained.

[0012] Another object of the present disclosure is to propose a method for solving this problem.

[0013] The technical objectives of the present disclosure are not limited to the aforementioned technical objectives, and a person of ordinary skill in the art will obviously appreciate other technical objectives not mentioned above from the following description.

[0014] Technical Solution

[0015] A method performed by a user equipment in a wireless communication system according to an embodiment of the present disclosure includes: receiving configuration information related to multiple control resource sets (CORESETs), receiving configuration information related to a timing advance group (TAG), and releasing the configuration related to uplink transmission based on the expiration of a time alignment timer related to the TAG.

[0016] A CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information.

[0017] The TAG includes i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index.

[0018] The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG.

[0019] A configuration related to uplink transmission is released based on expiration of the first time alignment timer.

[0020] The configuration related to uplink transmission may be related to at least one of i) a physical uplink control channel (PUCCH) and / or ii) a sounding reference signal (SRS).

[0021] Based on expiration of the first time alignment timer, the PUCCH for i) all serving cells or ii) serving cells belonging to the first TAG may be released.

[0022] Based on expiration of the first time alignment timer, the SRS for i) all serving cells or ii) serving cells belonging to the first TAG may be released.

[0023] Based on the first time alignment timer expiration,

[0024] At least one of i) configured downlink assignments, ii) configured uplink grants, and / or iii) physical uplink shared channel (PUSCH) resources may be cleared for all serving cells or serving cells belonging to the first TAG.

[0025] PUSCH resources may be associated with semi-persistent CSI reporting.

[0026] Based on the first time alignment timer expiration,

[0027] Uplink transmission except for random access preamble transmission and MsgA transmission may not be performed on all serving cells or serving cells belonging to the first TAG.

[0028] The method may further include receiving downlink control information (DCI) and sending a random access preamble.

[0029] The DCI may include information related to the Physical Downlink Control Channel (PDCCH) sequence. The random access procedure may be initiated by the PDCCH sequence.

[0030] The DCI may include a synchronization signal / physical broadcast channel block index (SSB index) associated with the PDCCH sequence.

[0031] The SSB index associated with the PDCCH order may be included in i) a first SSB group associated with the first CORESET pool index, or ii) a second SSB group associated with the second CORESET pool index.

[0032] The reference signal received power (RSRP) of the SSB based on the SSB index associated with the PDCCH order is greater than the RSRP threshold,

[0033] The random access preamble may be sent based on an SSB index associated with the PDCCH order.

[0034] The SSB based on the SSB index associated with the PDCCH order may be associated with at least one contention free random access (CFRA) resource.

[0035] According to the reference signal received power (RSRP) of the SSB based on the SSB index associated with the PDCCH order being equal to or less than the RSRP threshold,

[0036] The random access preamble may be sent based on an SSB index within a first SSB group or a second SSB group to which an SSB index associated with a PDCCH order belongs.

[0037] An SSB based on an SSB index within the first SSB group or the second SSB group may be associated with at least one contention-based random access (CBRA) resource.

[0038] A second TA associated with a second TAG may be determined based on i) a first TA associated with the first TAG and ii) an offset value.

[0039] The method may further include receiving a timing advance command.

[0040] The timing advance command may be associated with the first TAG or the second TAG.

[0041] For a specific serving cell in which one CORESET pool index is configured among the serving cells belonging to the first TAG and the second TAG:

[0042] A timing advance (TA) for uplink timing may be determined as a specific TA.

[0043] The specific TA may be i) a first TA associated with a first TAG or ii) a TA configured for a specific serving cell.

[0044] A user equipment operating in a wireless communication system according to another embodiment of the present disclosure includes one or more transceivers, one or more processors, and one or more memories, which are operably connected to the one or more processors and store instructions for configuring the one or more processors to perform operations based on execution by the one or more processors.

[0045] The operations include receiving configuration information associated with a plurality of control resource sets (CORESETs), receiving configuration information associated with a timing advance group (TAG), and releasing configuration associated with uplink transmission based on expiration of a time alignment timer associated with the TAG.

[0046] A CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information.

[0047] The TAG includes i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index.

[0048] The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG.

[0049] A configuration related to uplink transmission is released based on expiration of the first time alignment timer.

[0050] A device according to another embodiment of the present disclosure includes: one or more memories; and one or more processors functionally connected to the one or more memories.

[0051] The one or more memories include instructions for configuring the one or more processors to perform operations based on execution by the one or more processors, and

[0052] The operation includes receiving configuration information related to a plurality of control resource sets (CORESETs), receiving configuration information related to a timing advance group (TAG), and releasing configuration related to uplink transmission based on expiration of a time alignment timer related to the TAG.

[0053] A CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information.

[0054] The TAG includes i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index.

[0055] The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG.

[0056] A configuration related to uplink transmission is released based on expiration of the first time alignment timer.

[0057] One or more non-transitory computer-readable media according to another embodiment of the present disclosure store one or more instructions.

[0058] One or more instructions executable by one or more processors configure the one or more processors to perform operations.

[0059] The operation includes receiving configuration information related to a plurality of control resource sets (CORESETs), receiving configuration information related to a timing advance group (TAG), and releasing configuration related to uplink transmission based on expiration of a time alignment timer related to the TAG.

[0060] A CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information.

[0061] The TAG includes i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index.

[0062] The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG.

[0063] A configuration related to uplink transmission is released based on expiration of the first time alignment timer.

[0064] A method performed by a base station in a wireless communication system according to another embodiment of the present invention includes: sending configuration information related to a plurality of control resource sets (CORESETs), and sending configuration information related to a timing advance group (TAG).

[0065] A CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information.

[0066] Based on the expiration of the time alignment timer associated with the TAG, the configuration associated with uplink transmission except for the random access preamble and MsgA is released.

[0067] The TAG includes i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index.

[0068] The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG.

[0069] A configuration related to uplink transmission is released based on expiration of the first time alignment timer.

[0070] A base station operating in a wireless communication system according to another embodiment of the present disclosure includes one or more transceivers, one or more processors, and one or more memories, wherein the one or more memories are operably connected to the one or more processors and store instructions that configure the one or more processors to perform operations based on execution by the one or more processors.

[0071] The operation includes: sending configuration information related to a plurality of control resource sets (CORESETs) and sending configuration information related to a timing advance group (TAG).

[0072] A CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information.

[0073] Based on the expiration of the time alignment timer associated with the TAG, the configuration associated with uplink transmission except for the random access preamble and MsgA is released.

[0074] The TAG includes i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index.

[0075] The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG.

[0076] A configuration related to uplink transmission is released based on expiration of the first time alignment timer.

[0077] Beneficial Effects

[0078] According to an embodiment of the present disclosure, based on the expiration of a timer associated with a first CORESET pool index among a plurality of time alignment timers, a release operation upon expiration of a time alignment timer is performed in a limited manner.

[0079] Therefore, it is possible to resolve the ambiguity about what operation should be performed when one of the multiple time alignment timers expires. In addition, it is possible to prevent the reliability of UL / DL operation from being degraded due to frequent occurrence of UL configuration release operations and unnecessary increase in signaling overhead due to UL reconfiguration of each serving cell.

[0080] According to an embodiment of the present disclosure, based on the RSRP of the SSB indicated by the SSB index related to the PDCCH order being less than or equal to the RSRP threshold, a random access preamble is sent based on the SSB index within the first SSB group or the second SSB group to which the SSB index related to the PDCCH order belongs.

[0081] Therefore, even if the RSRP of the SSB corresponding to the indicated SSB index related to the PDCCH order is less than or equal to the RSRP threshold for utilizing the CFRA resource, RACH transmission can be performed based on the SSB index to obtain a TRP-specific TA value. In other words, the problem of the existing solution that a TRP-specific TA cannot be obtained when utilizing a random SSB index due to the RSRP of the SSB based on the indicated SSB index can be solved.

[0082] Effects that can be obtained from the present disclosure are not limited to the above-mentioned effects, and other technical effects that are not mentioned can be clearly understood by those skilled in the art to which the present disclosure belongs from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] Figure 1 A MAC RAR according to an embodiment of the present disclosure is illustrated.

[0084] Figure 2 A timing advance command MAC CE according to an embodiment of the present disclosure is illustrated.

[0085] Figure 3 is a flowchart illustrating a method performed by a UE in a wireless communication system according to an embodiment of the present disclosure.

[0086] Figure 4 is a flowchart illustrating a method performed by a base station in a wireless communication system according to another embodiment of the present disclosure.

[0087] Figure 5 The configurations of a first device and a second device according to an embodiment of the present disclosure are illustrated. DETAILED DESCRIPTION

[0088] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Figure 1The detailed description disclosed above is intended to describe exemplary embodiments of the present disclosure, rather than to describe the only embodiment for performing the present disclosure. The following detailed description includes details to provide a complete understanding of the present disclosure. However, those skilled in the art will appreciate that the present disclosure may be performed without the details.

[0089] In some cases, in order to prevent the concepts of the present disclosure from being unclear, known structures or devices may be omitted, or may be shown in the form of a block diagram focusing on the core functions of each structure and device.

[0090] In the following, downlink (DL) refers to communication from a base station to a terminal, and uplink (UL) refers to communication from a terminal to a base station. In the downlink, the transmitter may be part of a base station, and the receiver may be part of a terminal. In the uplink, the transmitter may be part of a terminal, and the receiver may be part of a base station. The base station may be expressed as a first communication device, and the terminal may be expressed as a second communication device. The following terms may be used instead of a base station (BS), including: fixed station, Node B (Node B), evolved Node B (eNB), next generation Node B (gNB), base transceiver system (BTS), access point (AP), network (5G network), AI system, road side unit (RSU), vehicle, robot, unmanned aerial vehicle (UAV), AR (augmented reality) device, VR (virtual reality) device, and the like. In addition, the terminal may be fixed or mobile and may be replaced by the following terms, including: user equipment (UE), mobile station (MS), user terminal (UT), mobile subscriber station (MSS), subscriber station (SS), advanced mobile station (AMS), wireless terminal (WT), machine type communication (MTC) device, machine-to-machine (M2M) device and device-to-device (D2D) device, vehicle, robot, AI module, unmanned aerial vehicle (UAV), AR (augmented reality) device, VR (virtual reality) device, etc.

[0091] Multiple transmit / receive point (M-TRP) related operations

[0092] The M-TRP transmission scheme in which M TRPs transmit data to one user equipment (UE) can be divided into two main types, eMBB M-TRP transmission, which is a scheme for increasing the transmission rate, and URLLC M-TRP transmission, which is a scheme for increasing the reception success rate and reducing the delay.

[0093] MTRP transmission based on SDCI or MDCI

[0094] From the perspective of downlink control information (DCI) transmission, the M-TRP (multi-TRP) transmission scheme can be classified into: i) an M-TRP transmission scheme based on multiple DCI (M-DCI), in which each TRP transmits different DCI, and ii) an M-TRP transmission scheme based on single DCI (S-DCI), in which one TRP transmits DCI.

[0095] R16 NR MTRP sent

[0096] The R16 NR standard supports S-DCI-based MTRP PDSCH and M-DCI-based MTRP PDSCH transmission schemes.

[0097] R16 MTRP PDSCH based on M-DCI

[0098] M-DCI-based MTRP PDSCH transmission is a way that each TRP schedules and transmits PDSCH via DCI. That is, TRP1 transmits PDSCH 1 via DCI 1, and TRP 2 transmits PDSCH 2 via DCI 2. When PDSCH 1 and PDSCH 2 overlap on the same frequency-time resource, the two PDSCHs are received by the same RE, thereby improving resource efficiency and increasing transmission capacity. To this end, the R16 standard has introduced a CORESET pool, which is a group of multiple CORESETs, and TRP 1 transmits PDCCH through a CORESET belonging to CORESET pool 0, and the PDSCH scheduled by the corresponding PDCCH is also transmitted by TRP 1. TRP 2 transmits PDCCH through a CORESET belonging to CORESET pool 1, and the PDSCH scheduled by the corresponding PDCCH is also transmitted by TRP 2. For PUSCH, a specific TRP can schedule the transmission of PUSCH to the UE through a CORESET belonging to each CORESET pool. For PUCCH, TRP 1 schedules part of the PUCCH resources to receive UCI, and TRP 2 schedules the remaining PUCCH resources to receive UCI. For PUSCH or PUCCH, the channels scheduled / used by each TRP are TDMed with each other and do not overlap. Therefore, an increase in transmission capacity cannot be expected, but the UE is able to independently transmit PUSCH / PUCCH to each of TRP 1 and TRP 2.

[0099] In addition, the UE may identify the PUSCH (or PUCCH) scheduled by the DCI received via different CORESETs (or CORESETs belonging to different CORESET groups) as the PUSCH (or PUCCH) sent to different TRPs, or identify the PUSCH (or PUCCH) of different TRPs. The scheme of UL transmissions (e.g., PUSCH / PUCCH) sent to different TRPs can also be applied to UL transmissions (e.g., PUSCH / PUCCH) sent to different panels belonging to the same TRP.

[0100] The CORESET group ID (or the COERSET pool index having the same meaning) described / mentioned in the present disclosure may represent the index / identification information (e.g., ID) and the like for distinguishing the CORESET of each TRP / panel. In addition, the CORESET group may be a group / union of CORESETs for distinguishing the CORESET of each TRP / panel classified by the index / identification information (e.g., ID) / CORESET group ID and the like. For example, the CORESET group ID may be specific index information defined in the CORESET configuration. For example, the CORESET group may be configured / indicated / defined by the index defined for each CORESET in the CORESET configuration. And / or, the CORESET group ID may represent the index / identification information / indicator and the like for distinguishing / identifying the configured CORESET associated with each TRP / panel, and the CORESET group ID described / mentioned in the present disclosure may be replaced and expressed with the specific index / specific identification information / specific indicator and the like for distinguishing / identifying the configured CORESET associated with each TRP / panel. The CORESET group ID, i.e., a specific index / specific identification information / specific indicator for distinguishing / identifying a configured / related CORESET to each TRP / panel, may be configured / indicated via higher layer signaling (e.g., RRC signaling) / L2 signaling (e.g., MAC-CE) / L1 signaling (e.g., DCI), etc. For example, it may be configured / indicated that PDCCH detection for each TRP / panel is performed in units of the corresponding CORESET group, and / or it may be configured / indicated that uplink control information (e.g., CSI, HARQ-A / N, SR) and / or uplink physical channel resources (e.g., PUCCH / PRACH / SRS resources) are managed / controlled separately for each TRP / panel in units of the corresponding CORESET group, and / or the HARQ A / N (processing / retransmission) of PDSCH / PUSCH, etc. scheduled for each TRP / panel may be managed in units of the corresponding CORESET group.

[0101] For example, a higher layer parameter ControlResourceSet IE (information element) is used to configure a time / frequency control resource set (CORESET). For example, a control resource set (CORESET) may be associated with detection and reception of downlink control information. The ControlResourceSet IE may include a CORESET-related ID (e.g., controlResourceSetID) / an index of a CORESET pool of a CORESET (e.g., CORESETPoolIndex) / a time / frequency resource configuration of a CORESET / TCI information associated with a CORESET, etc. For example, an index of a CORESET pool (e.g., CORESETPoolIndex) may be set to 0 or 1. In the description, a CORESET group may correspond to a CORESET pool, and a CORESET group ID may correspond to a CORESET pool index (e.g., CORESETPoolIndex). The ControlResourceSet (i.e., CORESET) may be configured via higher layer signaling (e.g., RRC).

[0102] Timing Advance (TA) Related Processes

[0103] The uplink frame number i from the user equipment (UE) shall start before the start of the corresponding downlink frame at the UE .

[0104] and The relevant uplink timing (eg, uplink frame) may be based on Table 1 below.

[0105] [Table 1]

[0106]

[0107] In Table 1, Can be based on N TA and N TA,offset Calculate / determine. TA and N TA,offset Can be configured / applied as follows.

[0108] N TA : 1) via Random Access Response (RAR), and 2) via Timing Advance Command (MAC-CE)

[0109] N TA,offset : 1) configure a specific value for each serving cell and 2) apply the predefined value appropriately to the serving cell based on duplex mode / FR

[0110] The following describes the above configuration / application in detail TA,offset and NTA method.

[0111] N TA,offset

[0112] Case 1) Each serving cell is configured with a specific value

[0113] For example, the UE may receive information including information about N TA,offset The configuration information may be received based on RRC signaling, and the following Table 2 shows the configuration information.

[0114] [Table 2]

[0115]

[0116] Case 2) Method of appropriately applying predefined values ​​based on duplex mode / FR to serving cell

[0117] For example, the UE can set N based on the duplex mode (TDD / FDD) / FR. TA,offset The predefined value of N is appropriately applied to the serving cell. TA,offset The value of .

[0118] [Table 3]

[0119]

[0120] N TA

[0121] Case 1) Method configured via Random Access Response (RAR)

[0122] For example, in a random access procedure (e.g., a 2-step RACH procedure or a 4-step RACH procedure), the UE may receive a RAR from the base station. The NTA may be determined / configured based on the RAR. Specifically, the RAR may include a timing advance command. The timing advance command indicates an index value (e.g., index value TA) related to the timing adjustment. The NTA may be determined based on the index value (see Table 5 below). The RAR may be based on the MAC RAR. Figure 1 Describe this.

[0123] Figure 1 A MAC RAR according to an embodiment of the present disclosure is illustrated.

[0124] refer to Figure 1 , MAC RAR may include a reserved bit (R), a timing advance command, a UL grant, and a temporary C-RNTI. The following Table 4 shows the MAC payload of MAC RAR.

[0125] [Table 4]

[0126]

[0127] Table 5 below shows the transmission timing adjustment based on the timing advance command.

[0128] [Table 5]

[0129]

[0130] Case 2) Configuration via Timing Advance Command (MAC-CE)

[0131] For example, NTA may be determined / configured based on MAC-CE. Specifically, NTA may be determined based on a timing advance command MAC CE. The timing advance command MAC CE may include a timing advance command. Since determining NTA based on the timing advance command is the same as described in Case 1, repeated description is omitted (see Table 5). Figure 2 Describe the Timing Advance Command MAC CE.

[0132] Figure 2 A timing advance command MAC CE according to an embodiment of the present disclosure is illustrated.

[0133] refer to Figure 2 , the timing advance command MAC CE may include a TAG ID and a timing advance command. Table 6 below shows the payload of the timing advance command MAC CE.

[0134] [Table 6]

[0135]

[0136] Timing Advance Group (TAG)

[0137] A timing advance group (TAG) refers to a group of serving cells using the same timing advance value. Table 7 below shows the definition of a TAG and configuration information related to the TAG.

[0138] [Table 7]

[0139]

[0140]

[0141]

[0142] process

[0143] Uplink time alignment can be performed based on Table 8.

[0144] [Table 8]

[0145]

[0146]

[0147]

[0148] The above contents (multiple TRPs and timing advance, etc.) can be applied in combination with the methods proposed in this specification, which will be described later, or can be supplemented to clarify the technical features of the methods proposed in this specification. The methods described below are classified only for the convenience of explanation, and some components of one method can be replaced with some components of another method, or can be applied in combination with each other.

[0149] Hereinafter, i) a method in which a base station configures / indicates multi-TA for a specific CC / BWP in uplink transmission of a terminal, and ii) a method in which a terminal requests / acquires multi-TA will be described, and subsequent terminal operations will be proposed.

[0150] According to the 3GPP standard up to NR Rel-17, the timing advance (TA) configuration of the UE uplink transmission of the base station can be performed via higher layer signaling to compensate for the propagation delay between the base station and the UE. In addition, the TA of a specific cell can be separately configured / managed through the concept / definition of a timing advance group (TAG).

[0151] So far, there is no method to support multiple TA values ​​within a specific cell. However, considering the scenario where the distances of different target TRPs to the UE vary greatly when M-TRP UL is transmitted, enhancements will be performed to be able to set / indicate multiple (two) TA values ​​in a specific CC / BWP.

[0152] In this case, it is necessary to discuss how the base station configures / indicates multiple TA values ​​to the UE or / and how to perform the connection relationship between multiple TA values ​​and UE UL channels / RS. As described in Rel-18 MIMO WID Target (RP-213598) in Table 9 below, the configuration of TA values ​​for M-TRP operation based on multi-DCI (M-DCI) is considered.

[0153] [Table 9]

[0154]

[0155] Here, TA (TA value) can be based on Figure 2 and the contents described in the above timing advance (TA) related process.

[0156] In the RAN1 and RAN2 standards before Rel-18, the base station is based on N TA and N TA,offsetThe base station can set N based on i) RAR MAC CE or ii) TA command MAC CE. TA . In addition, the base station can configure up to four TAGs for the UE for a specific cell or cell combination using the concept of a timing advance group (TAG). The base station can perform update / management on the NTA value for each TAG. In other words, the NTA value related to the uplink timing of the UE can be determined / set based on the RAR MAC CE / TA command MAC CE for each TAG.

[0157] In Rel-18 MIMO, to support different TA values ​​for UEs based on target TRP, i) the base station can set N in a specific CC / BWP. TA (or / and N TA,offset ) two TRP specific values, or ii) the base station can configure separate parameters (e.g. N TA,TRP1 and / or N TA,TRP2 ), so that in addition to N TA or / and N TA,offset In addition to the TRP value, a TRP-specific TA offset value is also configured / allocated. In method ii), when calculating the existing TA value of the UE, the TA offset may need to be additionally subtracted / added due to separate parameters. Hereinafter, the two TA values ​​managed by methods i) or / and ii) may be represented as TA1 (or the first TA) and TA2 (or the second TA). In this case, the two TA values ​​may correspond to two TAGs. For example, TA1 corresponding to TRP1 may be associated with TAG 1, and TA2 corresponding to TRP2 may be associated with TAG 2.

[0158] As described in the WID, the scenario that supports two TA values ​​is M-DCI-based M-TRP operation. In M-DCI-based M-TRP operation, each TRP can be classified based on the CORESET pool index associated with the CORESET present in the BWP. Based on the CORESET pool index, each TRP can be classified as i) a TRP that performs DL transmission (i.e., PDCCH, PDSCH), or / and ii) a target TRP for UL transmission. For example, CORESET 0 and 1 set to CORESET pool index 0 can correspond to TRP 1, and CORESET 2 and 3 set to CORESET pool index 1 can correspond to TRP 2.

[0159] In the unified TCI framework introduced in Rel-17 MIMO, a base station may dynamically indicate a specific reference RS to be used as a common beam for a DL / UL reception (Rx) / transmission (Tx) beam of a UE using a DL / UL joint TCI state and / or a DL / UL separate TCI state.

[0160] The DL / UL joint TCI state may be based on the joint TCI state configured for UL and DL operations. When the unifiedTCI-StateType of the serving cell is set to "joint", the joint TCI state may be configured based on the dl-OrJointTCI-StateList.

[0161] DL / UL separate TCI state can be based on DL TCI state and / or UL TCI state. When unifiedTCI-StateType of the serving cell is set to "separate", DL TCI state can be configured based on dl-OrJointTCI-StateList and UL TCI state can be configured based on ul-TCI-ToAddModList.

[0162] The TCI state (e.g., joint / DL TCI state) may be indicated / configured based on the dl-OrJoint-TCIStateList in the PDSCH-config. The dl-OrJoint-TCIStateList may i) provide a list of up to 128 TCI states (explicitlist→dl-OrJointTCI-StateToAddModList) or ii) indicate the serving cell and (DL / UL) BWP where the TCI state list (dl-OrJointTCI-StateToAddModList) is defined (unifiedTCI-StateRef→ServingCellAndBWP-Id). The TCI state (e.g., joint / DL TCI state) may provide a reference RS for quasi-co-location of DM-RS for PDSCH, DM-RS for PDCCH, and CSI-RS. The TCI state (e.g., joint TCI state) may provide a reference RS for determining uplink (UL) Tx spatial filters for PUSCH based on dynamic grant, PUSCH based on configured grant, and PUCCH resources and SRS.

[0163] The UL TCI state can be indicated / configured via ul-TCI-StateList in BWPUplinkDedicated. ul-TCI-StateList can i) provide a list of up to 64 UL TCI states (explicitlist→ul-TCI-ToAddModList), or ii) indicate the serving cell and UL BWP, where the UL TCI state applicable to the UL BWP is defined (unifiedTCI-StateRef→ServingCellAndBWP-Id).

[0164] The Rx / Tx beam of the DL / UL channel / RS that is not a common beam target may be configured as follows: The TCI state of the unified TCI framework may be configured for each channel / RS based on RRC and MAC CE signaling.

[0165] Until Rel-17, standardization was performed only when M / N, which is the number of DL / UL common beams to be supported in the unified TCI framework (the number of DL / UL TCI states), was M / N = 1. In other words, the unified TCI framework does not support M-TRP. Specifically, in a serving cell where two CORESET pool indexes are set (the value of coresetPoolIndex is more than one), unifiedTCI-StateType is not set.

[0166] Here, M / N represents the number of DL common beams (M) and / or the number of UL common beams (N). For example, M / N = 1 may mean that the number of DL common beams (DL TCI state) and / or the number of UL common beams (UL TCI state) is 1. For example, M / N = 1 may mean that the number of DL and UL common beams (joint TCI state) is 1.

[0167] If M / N > 1 is supported in Rel-18, two or more TCI states can have a connection relationship with the source / target TRP.

[0168] Specifically, in the M-TRP operation based on M-DCI, two or more TCI states corresponding to M / N > 1 may have a connection relationship with the CORESET pool index. As described above, the two TA values ​​of multiple TRPs may be configured / indicated in the same manner as the existing standard through higher layer signaling (eg, MAC CE).

[0169] In the case of a UE (UE after Rel-17) supporting unified TCI applied to FR 2, multiple TA values ​​may be connected / corresponded to two or more TCI states corresponding to M / N>1. For example, when M / N=2 or / and N=2, the first configured / indicated (first / lowest) TCI state may correspond to TA1 (e.g., TAG 1 or TA1 of TAG 1), and the second configured / indicated (second / second lowest) TCI state may correspond to TA2 (e.g., TAG 2 or TA2 of TAG 2).

[0170] Specifically, a specific payload may be included / added / defined in the MAC CE to configure / allocate / activate a TA value corresponding to each of two or more TCI states of M / N> 1. For example, a payload for allocating a target TCI state (group) for each TA value (e.g., TA1 and TA2) may be present in a MAC CE message for configuring two TA values.

[0171] The protocol for multiple TA values ​​is shown in Table 10 below.

[0172] [Table 10]

[0173]

[0174]

[0175]

[0176] The operations / methods / terms according to the embodiments of the present disclosure described below may be based on Table 10. For example, the operations / methods / terms according to the embodiments of the present disclosure described below may be interpreted / changed / applied based on Table 10.

[0177] For example, multiple TA values ​​may mean multiple timing advance groups (TAGs) or multiple TAG IDs. One TA value may mean one TAG (TAG ID).

[0178] For example, multiple TA values ​​can represent TA values ​​corresponding to multiple TAGs (multiple TAG IDs). One TA value can represent the TA value of one TAG (TAG ID) (in Table 1).

[0179] In a TCI state configuration (TCI state pool) of a unified TCI, two TRP-specific TA values ​​(e.g., two TAGs or TAs corresponding to two TAGs) may be connected / correspond to a specific TCI state (group). When two TA values ​​are connected / correspond to two TCI states with M / N>1, the UE may perform UL transmission using the TRP-specific TA value connected to each TCI state in UL transmission using each TCI state. For example, the timing of UL transmission based on a first TCI state may be determined based on a TA associated with the first TCI state (e.g., a first TAG or a first TA of a first TAG), and the timing of UL transmission based on a second TCI state may be determined based on a TA associated with the second TCI state (e.g., a second TAG or a second TA of a second TAG).

[0180] However, even if unified TCI is supported by the UE, the reference RS of UL spatialRelationInfo or / and UL TCI cannot be applied to FR 1 (frequency range 1). For example, the UE capability of spatialRelationInfo of the UE may be defined as shown in Table 11 below.

[0181] [Table 11]

[0182]

[0183] Referring to Table 11, FR1 does not support the spatial relationship of PUCCH and SRS (eg, UE operation in FR1).

[0184] Therefore, for FR1, when the base station configures / indicates two TA values ​​using the unified TCI framework, there may be ambiguity in UE operation.

[0185] The present disclosure describes i) a method for a BS to send multi-TA configuration / indication of a specific CC / BWP for uplink of a UE (especially FR1) (as described above), and ii) a method for a UE to request / acquire multi-TA, and proposes subsequent UE operations.

[0186] In the present disclosure, “ / ” may be interpreted as “and”, “or” or “and / or” based on the context.

[0187] Proposal 1

[0188] The UE may receive a unified TCI configuration corresponding to M / N > 1 (in FR1 operation). For example, the UE may receive configuration information of two or more unified TCI states from a base station (BS). The two or more unified TCI states may include at least one of: i) two or more joint TCI states, ii) two or more DL TCI states, and / or iii) two or more UL TCI states.

[0189] When two CORESET pool indexes within a CC / BWP are configured by the base station for the UE to perform M-TRP operation based on M-DCI, UL-related TCI states (e.g., DL / UL joint TCI states and / or DL / UL separate TCI states) connected to / corresponding to each of the two CORESET pool indexes may be configured / indicated. For example, the UE may receive configuration information of a plurality of CORESETs from the base station. A CORESET based on two CORESET pool indexes may be configured based on the configuration information. The UE may receive information indicating two UL-related TCI states (e.g., two joint TCI states or two UL TCI states) connected to / corresponding to / associated with the two CORESET pool indexes from the base station. Information indicating two UL-related TCI states may be received based on at least one of a DCI, a MAC CE, or an RRC message.

[0190] The two TRP-specific TA values ​​may be connected / correspond to two UL-related TCI states. In addition, the power control parameter set configured to each of the two UL-related TCI states may be used as the power control parameter set for each target TRP in an M-TRP UL transmission (e.g., M-TRP PUSCH / PUCCH repetition) (for S-DCI-based M-TRP operation).

[0191] Specifically, since UL spatialRelationInfo (UL TCI) information is not applicable in FR1, the TCI status for configuring / indicating two TA / PC parameter sets may be configured / used as follows.

[0192] The reference RS corresponding to QCL Type-D or / and UL spatialRelationInfo (UL TCI) may not be configured to both TCI states. For example, in each TCI state, the reference signal field (in QCL-Info) may not exist. For example, the UE may not expect to configure the reference signal field (in QCL-Info) in each TCI state.

[0193] If the reference RS corresponding to QCL type-D or / and UL spatialRelationInfo (UL TCI) is configured as two TCI states, the UE can skip / ignore / override the reference RS and perform UL transmission only using TA / PC information corresponding to each target TRP (e.g., first / second TCI or CORESET pool index 0 / 1).

[0194] As described above, the UE may determine TA / PC information corresponding to each target TRP (e.g., each of the two target TRPs) based on two TCI states. The UE may perform UL transmission for each target TRP based on the TA information / PC information. The UL transmission timing (e.g., uplink frame) of each target TRP may be determined based on the TA information (e.g., TAG or TA value of the TAG). The UL transmission power of each target TRP may be determined based on the PC information (e.g., one or more PC parameters).

[0195] The TCI state can be configured / indicated via RRC, MAC CE or / and DCI in the same manner as the existing Rel-17 operation. If the TCI state is indicated via DCI, the base station may use i) DL ( / UL) grant DCI, or ii) DL ( / UL) grant DCI without data scheduling. The base station may dynamically indicate the TCI state of each target TRP through the TCI field of the DCI. For example, if TCI indication via DCI as described above is performed in a CORESET with a specific CORESET pool index, the UE may use the corresponding TCI to receive / send a DL / UL channel / RS connected / corresponding to the CORESET pool index.

[0196] In this case, according to the Rel-17 standard, in the TCI indication via the grant DCI without data scheduling, the UE can send an Ack ( / Nack) after receiving the DCI (via PUCCH and / or PUSCH) (e.g., using an ACK / NACK mechanism similar to the SPS PDSCH release with both type 1 and type 2 HARQ-ACK codebooks).

[0197] If the above operation is performed in FR1 (ie, via TCI indication of grant DCI without data scheduling), the UE may skip Ack ( / Nack) transmission. Skipping Ack ( / Nack) transmission considers the following technical issues.

[0198] In Rel-17, the base station checks whether the UE has received the TCI state including beam information (e.g., reference RS) well for the UE's reception / transmission indicated via DCI. Thereafter, the base station can use the Tx / Rx beam of the base station corresponding to the indicated TCI information in subsequent DL / UL transmission / reception. On the other hand, the TCI state indication that does not include the UE's Tx / Rx beam information allows the base station to configure / indicate two TAs (e.g., two TAGs or two TAs corresponding to two TAGs) and two PCs (e.g., two parameter sets). Whether the TA / PC indication is successfully sent can be determined by the UE's subsequent transmission. Specifically, after the base station receives the UE's subsequent UL transmission, it can be determined whether the TA / PC indication of the previous DCI has been successfully sent to the UE, and the UE has performed UL transmission based on the indication.

[0199] Accordingly, the UE may skip sending the Ack ( / Nack) for the TCI status indication in FR1 (the TCI status indication does not include the UE's Tx / Rx beam information).

[0200] In addition, since Rx / Tx beam indication is performed dynamically in the existing Rel-17 unified TCI framework, concepts such as beam application time (BAT) have been defined to determine at which time the UE should perform the change of the corresponding Rx / Tx beam starting from the time of DCI reception. For example, the beamAppTime parameter can be set based on PDSCH-config. The beamAppTime parameter indicates the first time slot to which the unified TCI indicated by DCI is applied. The beamAppTime parameter can indicate the number of symbols (Y) (e.g., n1, n2, n4, n7, n14, n28, n42, n56, n70, n84, n98, n112, n224, n336). The first time slot can be a time slot of at least Y symbols after the last acknowledgment (Ack) symbol of the joint or separate DL / UL beam indication.

[0201] As described above, when the unified TCI framework is used to configure / indicate TA / PC, BAT can be used as a setting value for the time when ULTA / PC should be applied. Alternatively / and, since the TCI state is independent of the beam application, the UE may not expect to configure BAT or may expect the BAT value to be set to 0. As a specific example, it can be assumed that the unified TCI state of FR1 is indicated by DCI (e.g., DL granted DCI, UL granted DCI, DCI without DL grant, or DCI without UL grant). Since the indicated unified TCI state is independent of the beam application, the transmission of HARQ-ACK information of the DCI can be skipped. Since the transmission of HARQ-ACK information is skipped, the time (e.g., symbol, time slot, subframe, or frame) at which the indicated unified TCI state is applied cannot be determined by the beamAppTime parameter. In this case, even if the beamAppTime parameter is configured, the UE may not use the beamAppTime parameter. In other words, the UE may ignore the beamAppTime parameter. For example, the time (e.g., symbol, time slot, subframe, or frame) at which the indicated unified TCI state is applied can be determined without applying the beamAppTime parameter. For example, the time of the unified TCI state indicated by the application can be determined regardless of the beamAppTime parameter.

[0202] Proposal 2

[0203] For two TRP-specific TA values ​​or / and two TRP-specific PC parameter sets, the base station can configure separate parameters. Specifically, (in FR1 operation) two TRP-specific TA values ​​or / and two TRP-specific PC parameter sets can be configured / connected / correspond to separately configured parameters.

[0204] The separate parameters may include TRP specific TA values. In this case, the parameters may be configured as i) or ii) below.

[0205] i) A single parameter including both the first TA value and the second TA value may be configured.

[0206] ii) Two parameters may be configured. The first parameter may include a first TA value, and the second parameter may include a second TA value.

[0207] The separate parameters may include a TRP specific PC parameter set. In this case, the parameters may be configured as per i) or ii) below.

[0208] i) A single parameter including a first PC parameter set and a second PC parameter set may be configured.

[0209] ii) Two parameters may be configured. The first parameter may include a first PC parameter set, and the second parameter may include a second PC parameter set.

[0210] In i), a specific CORESET pool index may be connected to / correspond to a specific TA value or / and a specific PC parameter set in a single parameter. For example, CORESET pool index 0 may be connected to a first TA value / first PC parameter set, and CORESET pool index 1 may be connected to a second TA value / second PC parameter set.

[0211] In ii), a specific CORESET pool index may be connected to / correspond to a specific parameter of the two parameters. For example, CORESET pool index 0 may be connected to the first parameter, and CORESET pool index 1 may be connected to the second parameter.

[0212] As described above, the first TA value / first PC parameter set and the second TA value / second PC parameter set may be configured as specific parameters and may be connected to a specific CORESET pool index. When transmitting UL associated with / corresponding to a specific CORESET pool index, the UE may perform UL transmission by utilizing a TRP-specific TA value or / and a TRP-specific PC parameter set connected to the corresponding CORESET pool index.

[0213] For more flexible configuration, the TRP-specific TA value or / and two TRP-specific PC parameter sets corresponding to the above two TA values ​​may be configured / connected / mapped / updated in each CORESET (group) configuration. Therefore, the UE is able to perform UL transmission by utilizing the TRP-specific TA value or / and TRP-specific PC parameter set configured for the corresponding CORESET when performing UL transmission related to a specific CORESET (group).

[0214] In the above embodiment, the expression “(a specific parameter and another parameter) may be connected / correspond” may mean that the specific parameter and another parameter can be associated via RRC / MAC CE / DCI signaling.

[0215] Unless the embodiments of Proposal 1 and Proposal 2 are mutually exclusive, the embodiments of Proposal 1 and the embodiments of Proposal 2 can be combined and applied to UE / BS operations. For example, the operation of configuring a unified TCI (Proposal 1) and the operation of configuring separate parameters (Proposal 2) cannot be combined, but other embodiments can be combined and applied. Specifically, the embodiments of Proposal 1 and the embodiments of Proposal 2 related to two TRP-specific TA values ​​(two TRP-specific PC parameter sets) can be combined and applied to UE / BS operations.

[0216] Multi-TA acquisition

[0217] In order to configure the above-mentioned multiple TA values, it is necessary to determine how the BS will request / acquire multiple TA values. Hereinafter, a method for BS / UE to acquire multiple TA values ​​and a terminal operation are proposed. Specifically, Proposal 3 below proposes a method for UE to perform two TA acquisition without RACH enhancement and a method for configuring TA in the BS, and Proposal 4 proposes a method for UE to perform two TA acquisition through RACH enhancement and a method for configuring TA in the BS.

[0218] Hereinafter, a first TA or a second TA connected / corresponding to a specific CORESET pool index may mean a first TA or / and a second TA connected / corresponding to a first TCI state or / and a second TCI state (for common beam operation in a unified TCI framework).

[0219] Hereinafter, the first TA and the second TA may mean the first / second TA value managed for configuring two TRP specific TA values ​​within a specific TAG (i.e., one TAG). Alternatively, the first TA and the second TA may mean the first TA value and the second TA value managed corresponding to different TAGs (first TAG and second TAG) for the same CC (set).

[0220] Proposal 3

[0221] Hereinafter, a method of performing two-TA acquisition and a method of configuring a TA in a BS without RACH boosting will be described.

[0222] Proposal 3-1

[0223] The UE may perform RACH transmission using a single (and / or primary / first) TA in a RACH transmission process including initial access (e.g., RACH in PDCCH order, RACH transmitted when a TA timer expires, etc.). The BS may measure the first / second TA by receiving a subsequent SRS of the UE. That is, a method of configuring / indicating an implicit / explicit connection / correspondence relationship between a specific SRS resource (set) and a specific CORESET pool index is proposed.

[0224] For the aperiodic SRS resource (set) corresponding to dynamic scheduling, the following operations may be performed: the UE may receive an SRS triggering DCI in a CORESET with a specific CORESET pool index. At this time, the aperiodic SRS resource (set) sent by the UE may be connected / corresponding to the specific CORESET pool index.

[0225] For the periodic / semi-persistent SRS resource(s) sent by the UE via RRC / MAC CE signaling, the following operations may be performed. The BS may (explicitly) configure / connect / correspond to the associated CORESET pool index for a specific SRS resource(s). In this way, the UE / BS may know which CORESET pool index a specific SRS resource(s) is connected / corresponds to.

[0226] Therefore, the BS / UE can understand that the specific P / SP / AP SRS resource (set) sent by the UE is associated / corresponds to a specific CORESET pool index. In other words, the BS can identify the CORESET pool index associated / corresponds to the specific P / SP / AP SRS resource (set) sent by the UE. The BS can measure the first TA or / and the second TA through the SRS sent by the UE.

[0227] According to an embodiment, the first ( / primary) TA may be acquired through an existing RACH procedure. The second TA may be acquired through an SRS associated with CORESET pool index 1 as described above.

[0228] Proposal 3-2

[0229] The BS may measure the first TA or / and the second TA connected / corresponding to a specific CORESET pool index through Proposal 3-1. The BS may configure / indicate a TRP specific TA value (ie, the first / second TA) by utilizing the enhanced RAR MAC CE format or / and the enhanced TA command MAC CE.

[0230] As an example, the BS may configure the target CORESET pool index in the enhanced MAC CE format. Thus, the TA value associated with / corresponding to the corresponding CORESET pool index may be configured / indicated. As a specific example, the enhanced MAC CE format may include a field indicating the target CORESET pool index.

[0231] As an example, the BS may configure the first / second TCI corresponding to M / N>1 as a target for TRP-specific common beam operation in the enhanced MAC CE format. In this way, the TA value associated / corresponding to the first / second TCI may be configured / indicated. As a specific example, the enhanced MAC CE format may include a field indicating a target TCI (e.g., a first TCI state or a second TCI state).

[0232] As an example, the BS may configure a specific joint and / or separate UL TCI state index as a target in the enhanced MAC CE format. In this way, the TA value to be applied to the corresponding TCI state may be configured / indicated. Specifically, the TA value in the MAC CE format for configuring / indicating the second TA value may be configured / specified / indicated to have a TA granularity or / and value range that is different from the first TA value in the same MAC CE format. This is because in M-TRP operation, the difference in UL TA values ​​for different TRPs may differ from the DL timing reference by the CP length or more. The granularity of the second TA value (when the same number of bits as the first TA value is used) can be represented by a step size that is slightly larger than the first TA value. The value range of the second TA value (when the same number of bits as the first TA value is used) can be represented by a value range that is slightly larger than the first TA value.

[0233] As described above, the BS may configure / indicate the first / second TA for a specific target CORESET pool index / target common TCI / target TCI state. In the transmission of the UL channel / RS (especially the SRS in Proposal 3-1) associated with the target CORESET pool index / target common TCI / target TCI state, the BS may perform uplink transmission by applying the configured / indicated first / second TA value.

[0234] The BS can perform update / activation of the TRP-specific TA value based on measuring the UE's TRP-specific SRS transmission based on Proposal 3-1 after configuring / indicating the TRP-specific TA through Proposal 3-2.

[0235] Proposal 4

[0236] Hereinafter, a method of performing two TA acquisition and a method of configuring a TA in a BS without RACH boosting will be described.

[0237] Proposal 4-1

[0238] A method may be considered to support TRP-specific RACH transmission for TRP-specific TA measurements.

[0239] The BS may perform grouping on the SSBs (SS / PBCH blocks) used by the UE for RACH transmission. The BS may associate / correspond a specific SSB group with a specific CORESET pool index. For example, SSBs corresponding to SSB indexes 0 to 31 may be connected to / correspond to CORESET pool index 0, and SSBs corresponding to SSB indexes 32 to 64 may be connected to / correspond to CORESET pool index 1. Here, the SSB index may be an SS / PBCH index of an SS / PBCH block.

[0240] Based on the grouping, the BS may configure / instruct to utilize a specific SSB index when configuring / instructing to send a RACH (of PDCCH order) to the UE. RACH may mean a random access preamble. For example, the BS may send a DCI (e.g., DCI format 1_0) containing information related to the PDCCH order to the UE. The random access procedure is initiated by the PDCCH order. The UE sends a random access preamble to the BS. Information related to the PDCCH order may include an SS / PBCH index. The SS / PBCH index may be connected to / associated with a specific CORESET pool index, and a random access preamble may be sent based on the SS / PBCH index.

[0241] By having the UE send a RACH corresponding to an SSB (based on a specific SSB index), the BS can measure a TRP specific TA associated / corresponding to each CORESET pool index by utilizing the RACH.

[0242] According to an embodiment, multiple RACH transmissions may be indicated / scheduled to the UE via a single PDCCH (e.g., a single DCI) so that when the BS indicates (PDCCH-sequential) RACH transmission, the UE may send a RACH associated with each CORESET pool index. As a specific example, a single DCI may include information related to the PDCCH sequence. At this time, the information related to the PDCCH sequence may include two SS / PBCH indexes. The UE may send two random access preambles to the BS based on the two SS / PBCH indexes. In this way, overhead / delay may be reduced through a single PDCCH transmission, and the UE may be instructed to send all RACHs sent to each TRP. The BS may perform TA measurements for each TRP at a time.

[0243] According to an embodiment, the connection / correspondence between a specific SSB group and a specific CORESET pool index can be configured / defined / specified by connecting / corresponding to a specific CORESET pool index and a PRACH preamble index / RACH timing / PRACH mask index. Specifically, a DCI related to a PDCCH order (e.g., DCI format 1_0) may include a random access preamble index, an SS / PBCH index, and a PRACH mask index. When the value of the random access preamble index is not zero, the PRACH mask index indicates a RACH timing associated with the SS / PBCH indicated by the SS / PBCH index. A specific CORESET pool index may be configured to be connected / corresponding to at least one of a PRACH preamble index, a PRACH mask index, or a RACH timing.

[0244] In addition, if a connection / correspondence relationship between a specific SSB group and a specific CORESET pool index is defined / configured, the following operations may be performed. The BS may schedule RACH transmission of the UE according to the PDCCH order through the CORESET with the specific CORSET pool index. At this time, the UE may perform RACH transmission corresponding to the SSB connected / corresponding to the specific CORESET pool index (or may force such RACH transmission) (even if there is no SSB index indication in the corresponding PDCCH). In other words, the UE may perform RACH transmission based on the CORESET pool index of the CORESET for which the DCI (related to the PDCCH order) is received.

[0245] The RACH transmission in the above proposal 4-1 cannot be used for RACH transmission at the time of initial access.

[0246] Even if the UE performs TRP-specific RACH transmission as described above, since the UE performs all operations based on a specific SSB in the RA process, the TA value is not changed during UL transmission in the RA process. That is, the UE performs UL transmission by utilizing the same TA value. The RA process may include a 4-step RACH process and / or a 2-step RACH process. For example, a 4-step RACH process (e.g., contention-based RACH) may include operations of sending message 1 (preamble), receiving message 2 (RAR), sending message 3 (PUSCH), and receiving message 4 (contention resolution). For example, a 2-step RACH procedure may include operations of sending Msg A (preamble and PUSCH) and receiving Msg B (RAR).

[0247] Proposal 4-2

[0248] Hereinafter, a method for managing a TRP-specific TA timer will be described.

[0249] According to the existing TA maintenance operation, when the timer corresponding to the primary timing advance group (PTAG) expires due to timeAlignmentTimer (per TAG), the UE can release UL transmission and send RACH. This embodiment proposes a method for managing timeAlignmentTimer corresponding to the TA timer as TRP-specific.

[0250] The UE may manage up to two TA timers corresponding to CORESET pool indexes 0 and 1 or / and the first and second TA values ​​within a single TAG. Here, the two corresponding timers may be timers configured for different TAGs for different TRPs.

[0251] According to the existing operation, when the TA timer expires, the UE sends a RACH corresponding to a random SSB (e.g., an SSB based on one of the SSB indexes). On the other hand, according to this embodiment, when the TA timer associated with / corresponding to a specific CORESET pool index or / and a specific first / second TA value expires, the UE may send a RACH based on the CORESET pool index associated with / corresponding to the expired TA timer. That is, a RACH corresponding to the SSB connected with / corresponding to the corresponding CORESET pool index may be sent.

[0252] By such operation, when the TA value corresponding to the TRP expires, the UE can send a RACH for a specific TRP. The BS can measure the TA value of the UE from the corresponding TRP and configure / indicate / update the TRP-specific TA value to the UE (as in Proposal 3-2).

[0253] In addition, it can be assumed that in the existing operation, when the timer corresponding to the PTAG expires, a UL out-of-sync (OOS) operation is performed, but in the case where two TRP-specific timers corresponding to the first and second TAs are managed respectively as in the above-mentioned Proposal 4-2, one timer expires and the other timer does not expire. In this case, the UE may not need to perform all predefined UL OOS operations (e.g., not perform an RRC release operation, etc.). If both timers expire, all predefined UL OOS operations may need to be performed.

[0254] Proposal 4-3

[0255] Hereinafter, a method for a BS to send a RAR corresponding to a TRP-specific RACH transmission will be described.

[0256] According to the above proposals 4-1 or / and 4-2, the specific RACH transmission of the UE corresponds to a specific SSB. According to the correspondence between the SSB index and the CORESET pool index, the specific RACH transmission and the specific CORESET pool index naturally have a corresponding relationship. A method is proposed in which the BS sends the RAR as TRP-specific for the TRP-specific RACH transmission of the UE.

[0257] The BS may receive a specific RACH corresponding to a specific CORESET pool index, and the BS may send a RAR of the corresponding RACH to the UE based on a portion of the CORESETs in the CORESET with the specific CORESET pool index. For example, the portion of the CORESET may be the CORESET with the lowest index in the CORESET configured with the corresponding CORESET pool index.

[0258] In the existing standard operation, the UE may receive the configuration of the type 1-PDCCH common search space (CSS) set for receiving the RAR from the BS. Specifically, the type 1-PDCCH CSS set may be configured based on the ra-searchspace of the PDCCH-ConfigCommon IE. For example, the RAR may be received based on the PDCCH candidates in the monitoring search space set (SS set).

[0259] Proposal 4-3 proposes a method that enables the UE to receive TRP-specific RARs through a separate UE-specific search space (USS) set in addition to the Type 1-PDCCH CSS set.

[0260] According to an embodiment, a method of connecting / configuring a CORESET to receive separate USS sets and TRP-specific RARs may be considered. Each USS set may be connected / corresponding to a CORESET with a different CORESET pool index.

[0261] According to an embodiment, the BS may transmit a RAR for a RACH for first / primary (and / or corresponding to CORESET pool index 0) TA value measurement through an existing type-1-PDCCH CSS set. According to an embodiment, the BS may transmit a RAR for a RACH for first / primary (and / or corresponding to CORESET pool index 1) TA value measurement through an existing type-1-PDCCH CSS set. When a USS set is used for TRP-specific RAR reception as described above, a separate RNTI for TRP-specific RAR reception may be configured in the UE.

[0262] According to an embodiment, the UE may receive a TRP-specific RAR based on the configuration of multiple CSS sets (eg, configuration of two CSS sets considering two TRPs). Each USS set may be connected / corresponding to a CORESET with a different CORESET pool index.

[0263] The MAC CE format sent via such a TRP-specific RAR may include all configurations / indications of multiple TA values ​​within a specific CC / BWP, as described in Proposal 3-2 above. Alternatively, the MAC CE format sent via a TRP-specific RAR may only include configurations / indications of TA values ​​associated / corresponding to the CORESET pool index through which the RAR is sent.

[0264] For the TA value associated / corresponding to a specific CORESET pool index indicated by the MAC CE format, the UE may specify / define the DL timing reference based on the reception of the RAR (UL grant DCI) sent in the CORESET with the corresponding CORESET pool index. The UE may apply the TA value indicated from the corresponding DL timing reference. In the case of M-TRP in a non-ideal backhaul scenario based on M-DCI (e.g., a scenario where there is no coordination between TRPs), the DL timing references between TRPs may be significantly different. In this case, the BS may indicate to the UE the appropriate TRP-specific TA value for each DL timing reference of each TRP through the above operations.

[0265] Proposal 5

[0266] Proposal 5 describes additional embodiments related to Proposal 4. Specifically, in the following, i) embodiments regarding timers associated with two TAs in Proposal 4-2, and ii) embodiments regarding RAR corresponding to TRP-specific RACH transmission of Proposal 4-1 and corresponding RACH transmission of Proposal 4-3 will be examined in turn.

[0267] Proposal 5-1

[0268] Hereinafter, a method for managing timers associated with two TAs will be described.

[0269] In the above-mentioned Proposal 4-2, a method for managing a TA for each TRP (TRP-specific TA) in a UE-specific CC / BWP in an M-TRP environment based on M-DCI is proposed. Specifically, according to Proposal 2, a timer associated with each TA is managed separately. A method different from the operation of the above-mentioned Proposal 4-2 may be considered.

[0270] Specifically, according to Proposal 5-1, when the timer of a specific TA value (eg, the first TA value) among two TA values ​​expires, the above-mentioned UL OOS operation may be performed. In addition, this embodiment may assume / consider at least one of the following technical matters.

[0271] Among multiple TRPs, there may be a master TRP (eg, a CORESET pool with CORESET pool index 0) that transmits system information. For example, a specific TA value may be associated with the master TRP (CORESET pool index 0).

[0272] 2) The second TA value of the second TRP (ie, the CORESET pool with a CORESET pool index of 1) may be managed by an offset value relative to the first TA value of the first TRP (ie, the CORESET pool with a CORESET pool index of 0).

[0273] Only one TA-related timer may be configured in the UE. For example, a timer (ie, timeAlignmentTimer) may be configured only for the first TA value. In this case, UL OOS operation may be performed based on the expiration of the configured timer.

[0274] A timer associated with each TA may be configured in the UE. That is, a timer associated with multiple TAs may be configured in the UE. For example, timers (i.e., first and second timeAlignmentTimers) may be configured for the first TA value and the second TA, respectively. In this case, a UL OOS operation may be performed based on the expiration of the configured specific timer (first timeAlignmentTimer or second timeAlignmentTimer). The UL OOS operation may be based on an operation performed when a timer associated with a PTAG (or STAG) expires. For example, the UL OOS operation may include an action performed when the timeAlignmentTimer in Table 8 expires.

[0275] When the timer for a specific TA value (e.g., the first TA value) expires, the UE may perform a release operation on all UL channels / RSs (of CC / BWP associated with the corresponding TA value (or associated with the corresponding TAG)). More specifically, the UE may perform a release operation and a clear operation based on Table 8. Based on the expiration of the above timer, the UE may i) release the PUCCH and SRS, and ii) clear the configured downlink assignment, the configured uplink grant, and the PUSCH resources (e.g., the PUSCH resources used for semi-persistent CSI reporting). In addition, the UE may perform a RACH transmission to facilitate updating the expired TA value.

[0276] This proposal can be applied to both the case where the first TA and the second TA are managed in one TAG and the case where the first TA and the second TA are managed in two different TAGs.

[0277] Proposal 5-2

[0278] In the following, additional embodiments related to 1) TRP-specific RACH transmission operation and 2) RAR MAC CE or / and Timing Advance Command (TAC) MAC CE corresponding to RACH transmission will be examined.

[0279] In the above-mentioned proposal 4-1, a method of performing TRP-specific (CORESET pool-specific) RACH transmission by grouping SSBs is proposed. In this case, TRP-specific RACH transmission can be performed using a specific SSB index in RACH transmission configured by a higher layer (such as MIB) and RACH transmission ordered by PDCCH, and the same operation can be performed when CFRA (Contention-Free Random Access) transmission is (optionally) configured / indicated in both RACH transmission methods.

[0280] Meanwhile, when CFRA transmission (in PDCCH order) is configured / indicated according to the existing scheme, CFRA resources or CBRA resources may be used. Hereinafter, the details will be explained.

[0281] [1] Based on the RSRP of the SSB based on the SSB index configured / indicated for RACH transmission (e.g., based on the SSB index indicated by DCI related to the PDCCH order) being greater than a certain threshold (e.g., rsrp-ThresholdSSB), a RACH (or RA preamble) may be sent based on the configured / indicated SSB index. More specifically, a RACH (or RA preamble) may be sent based on a contention-free random access (CRFA) resource associated with the configured / indicated SSB index.

[0282] [2] Based on the RSRP of the SSB of the SSB configured / indicated for RACH transmission (e.g., based on the SSB index indicated by the DCI related to the PDCCH order) being less than or equal to a specific threshold (e.g., rsrp-ThresholdSSB), the CBRA resources may be sent based on a fallback operation. The UE may select any SSB. The RACH (or RA preamble) may be sent based on the selected SSB. More specifically, the RACH (or RA preamble) may be sent based on contention-based random access (CBRA) resources associated with the selected SSB. In the case of the existing scheme, it may be difficult to obtain a TRP-specific TA because the RACH transmission is performed based on any SSB. For example, another TA other than the TA for which the timer has expired may be obtained from the RACH transmission. In this case, TRP-specific TA management is not efficient.

[0283] According to an embodiment, the operations of [1] and [2] can be widely applied to Proposal 4-1 to solve the above-mentioned problem. Specifically, when CFRA transmission is configured / indicated (in RACH transmission configured by a higher layer and RACH transmission ordered by PDCCH), the UE can operate as follows.

[0284] [1] Based on the RSRP of the SSB corresponding to the configured / indicated SSB index being greater than a certain threshold, the UE can operate in the same manner as the existing scheme. That is, RACH (or RA preamble) can be sent based on the configured / indicated SSB index.

[0285] [2] Based on the RSRP of the SSB corresponding to the configured / indicated SSB index being less than or equal to a specific threshold, the UE may operate differently from the existing scheme. That is, instead of performing RACH transmission by selecting an arbitrary SSB, the UE may perform RACH (or RA preamble) transmission based on a specific SSB index. The specific SSB index may be one of the SSB indexes within the SSB group to which the configured / indicated SSB index belongs. Specifically, the UE may select an arbitrary SSB (SSB index) whose SSB group includes / corresponds to the configured / indicated SSB index, and perform RACH transmission based on the selected SSB index. The RACH (or RA preamble) may be sent based on a contention-based random access (CBRA) resource associated with the selected SSB within the SSB group including / corresponding to the configured / indicated SSB index.

[0286] According to the above-described embodiment, the following effects can be derived.

[0287] Even when CFRA-related operation ([1]) falls back to CBRA-related operation ([2]) through RSRP-related operation, the UE can perform RACH transmission for a specific SSB group (connected / corresponding to a specific CORESET pool index) as intended by the original BS. Through RACH transmission, the BS can obtain a TA value corresponding to the desired TRP. That is, even when the RSRP of the SSB corresponding to the SSB index related to the PDCCH order is less than or equal to the threshold for utilizing CFRA resources, RACH transmission can be performed based on the SSB index to obtain a TRP-specific TA value other than any SSB index.

[0288] According to an embodiment, the following operations may be considered with respect to RAR for RACH transmission (RACH transmission based on a specific SSB index belonging to a specific SSB group).

[0289] As an example, the RAR for RACH transmission related to a specific SSB group can be transmitted / received using a specific (same for each TRP) RNTI in a specific CSS set like the existing scheme. In other words, when the BS (UE) receives (transmits) a RACH related to a specific SSB group, a RAR based on a specific RNTI in a specific CSS set can be transmitted (received).

[0290] As an example, a RAR for RACH transmission associated with a specific SSB group may be transmitted / received in a CORESET (SS set) where a CORESET pool index associated with the group is configured as in Proposal 4-3. In other words, when a BS (UE) receives (transmits) a RACH associated with a specific SSB group, a RAR may be transmitted (received) in a CORESET (or SS set of a CORESET) in which a CORESET pool index associated with the group is configured.

[0291] According to an embodiment, for indication of a TA associated / corresponding to each TRP (CORESET pool index) as described in Proposal 4-3 (eg, indication of two TAs associated with two CORESET pool indexes), a method of indicating a TA value for each TRP may be considered.

[0292] Regarding the operation according to the embodiment, the following technical matters are considered. In the case of a non-ideal backhaul scenario assuming a main scenario of an M-TRP based on M-DCI, dynamic level coordination between two TRPs is not performed in RAR MAC CE and / or timing advance command (TAC) MAC CE transmission. Therefore, it is necessary to indicate the TA value for each TRP. In the following, the details will be explained.

[0293] As an example, two TAs within a single TAG situation can be assumed. In this case, the following operations can be performed.

[0294] TA value indication / update may be performed on the TA value in the target TAG based on the RAR MAC CE or / and TAC MAC CE associated with each CORESET pool index.

[0295] The TA value in the target TAG may be a TA value associated / corresponding to the corresponding CORESET pool index. Alternatively, the TA value in the target TAG may be a TA value of a sub-TAG (or TASG (TA subgroup)) associated / corresponding to the corresponding CORESET pool index. TA value indication / update may be performed only on the TA value.

[0296] As an example, two TAs within two TAGs may be assumed. That is, different TAs may be assumed to be based on different TAGs. In this case, the following operations may be performed.

[0297] TA value indication / update may be performed on a TA value corresponding to a TAG associated with a corresponding pool index based on a RAR MAC CE or / and a TAC MAC CE associated with each CORESET pool index.

[0298] In the first example (two TAs within a single TAG case) among the above examples, when there is a CC / BWP with a single CORESET pool configured within a CC / BWP group (or serving cell group) constituting the TAG, ambiguity occurs in UE operation as to which TA value among the two TA values ​​within the TAG should be used for UL transmission. In this case, at least one of the following operations i) and / or ii) may be performed.

[0299] i) When there is a single pool, the UE may assume the index of the pool to be 0. The UE may utilize the TA value associated with CORESET pool index 0 or the first TA value.

[0300] ii) The UE may utilize a set TA value. Specifically, the first TA value or the second TA value to be utilized in this case may be defined / set / indicated in advance or by the BS.

[0301] In two TAs within two TAG cases as a second example, when a single CORESET pool is configured for a specific CC / BWP (or specific serving cell) among the cross CC / BWP (or cross serving cell) forming the CC / BWP combination of the first TAG and the CC / BWP combination (serving cell combination) forming the second TAG, ambiguity arises in UE operation as to which TA value among the TA values ​​of the two TAGs should be used for UL transmission. In this case, at least one of the following operations i) and / or ii) may be performed.

[0302] i) When there is a single pool, the UE may assume the index of the pool to be 0. The UE may utilize the TA value corresponding to the TAG associated with the CORESET pool index 0, or may use the TA value corresponding to the first TAG.

[0303] ii) The UE may utilize the configured TA value. Specifically, the first or second TAG to be utilized in this case may be defined / set / indicated in advance or by the BS.

[0304] iii) In BS / UE configuration, it may be mandatory that the first TAG and the second TAG include the same CC / BWP combination.

[0305] In the description, the TAC MAC CE may include both an absolute TAC and a relative TAC by an offset value.

[0306] The embodiments of the above proposals 1 to 5 are applicable to the M-TRP environment based on intra-cell M-DCI and the M-TRP environment based on inter-cell M-DCI. That is, the operation of performing SSB grouping by CORESET pool index to achieve TRP-specific RACH transmission in schemes 4 and 5 can be extended to the operation of performing TRP (CORESET pool index or cell)-specific RACH transmission by dividing SSB into two groups based on the following i) and ii).

[0307] i) SSB group of the serving cell (in inter-cell M-DCI operation)

[0308] ii) Inter-cell SSB groups configured for non-serving cells (neighboring cells)

[0309] In addition, the TRP-specific RAR and / or TRP-specific TAC MAC CE operations in Scheme 4 and Scheme 5 can also be widely used in the M-TRP environment based on inter-cell M-DCI.

[0310] The embodiments of Proposals 3 and 5 may be applied to BS / UE operations in combination with the embodiments of Proposal 1 and the embodiments of Proposal 2, as long as these embodiments are not mutually exclusive. For example, an operation of performing two TA acquisitions without RACH enhancement (Proposal 3) and an operation of performing two TA acquisitions with RACH enhancement (Proposals 4 and 5) may not be combined, but other embodiments may be combined and applied. Specifically, the embodiment of Proposal 3 and the embodiments of Proposals 4 and 5 associated with two TRP-specific TA values ​​may be combined and applied to UE / BS operations.

[0311] Hereinafter, the signaling process based on the above embodiment will be described in detail.

[0312] An example of UE (or BS) operation based on at least one of the above-described embodiments (eg, at least one of Proposals 1 to 5) is as follows.

[0313] 1) The UE receives (sends) unified TCI-related configuration information and / or TRP-specific TA / PC-related configuration information.

[0314] The configuration information can be based on the content in schemes 1 to 5.

[0315] The UE transmits (receives) SRS or / and RACH based on scheme 3 or scheme 5 according to the BS configuration.

[0316] The BS may receive SRS or / and RACH and measure a TRP-specific TA, and then configure / indicate a TRP-specific TA value to the UE through (RAR or / and TA command) MAC CE based on Scheme 3 or Scheme 5.

[0317] 2) The UE receives (sends) a message for scheduling TRP-specific UL transmissions.

[0318] The above message may be based on at least one of the first PDCCH (first DCI) and / or the second PDCCH (first DCI).

[0319] The message may be associated with a specific CORESET pool index or / and a specific CORESET (group).

[0320] 3) The UE uses the TRP-specific TA / PC configuration information to send (receive) UL channels / RS based on this message.

[0321] The UL channel / RS may be based on at least one of SRS, PUSCH, PUCCH, or a random access preamble, and UL channel / RS transmission may be performed based on the contents of Proposals 1 to 5.

[0322] 4) The UE can manage the TRP-specific TA timer based on the contents of Proposals 4 and 5.

[0323] The UE / BS operations are only examples, and each operation (or step) is not required, and operations related to uplink transmission using the UE's TRP-specific TA / PC according to the above embodiments may be omitted or added depending on the UE / BS implementation.

[0324] In terms of implementation, the operation of the BS / UE in the above-mentioned embodiment (for example, the operation related to uplink transmission using a TRP-specific TA / PC of the UE based on at least one of Proposals 1 to 5) may be performed as described below. Figure 5 The devices (e.g., 5 and 110) are processed.

[0325] In addition, the operation of the BS / UE according to the above-mentioned embodiment (for example, the operation related to uplink transmission using a TRP-specific TA / PC of the terminal based on at least one of Proposals 1 to 5) can be used to drive at least one processor (for example, Figure 5 110 and 210) in the form of instructions / programs (e.g., instructions or executable code) stored in a memory (e.g., Figure 5 140 and 204).

[0326] In the following, reference will be made to Figure 3 and Figure 4 The above embodiments are described in detail with respect to the operations of the UE and the BS. The methods to be described below are distinguished only for convenience, and it goes without saying that some components of any one method may be replaced with some components of another method, or may be applied in combination with each other.

[0327] Figure 3 is a flowchart for describing a method performed by a UE in a wireless communication system according to an embodiment of the present disclosure.

[0328] refer to Figure 3 According to an embodiment of the present disclosure, a method performed by a UE in a wireless communication system includes a step of receiving configuration information related to a CORESET (S310), a step of receiving configuration information related to a TAG (S320), and a step of releasing configuration related to uplink transmission (S330).

[0329] In S310 , the UE receives configuration information related to a plurality of control resource sets (CORESETs) from the BS.

[0330] Based on the configuration information, a CORESET based on a first CORESET pool index and a second CORESET pool index (eg, a first CORESET and a second CORESET) may be configured. In other words, based on the configuration information, a CORESET based on two different control resource set (CORESET) pool indexes may be configured.

[0331] In S320, the UE receives configuration information related to a timing advance group (TAG) from the BS. The configuration information related to the TAG may be configuration information (eg, TAG-Config) based on Table 7 above.

[0332] In S330 , the UE releases the configuration related to uplink transmission based on expiration of the time alignment timer related to the TAG.

[0333] For example, based on the expiration of the time alignment timer, the UE may perform operations based on Table 8 above.

[0334] As an example, the UE may i) release the configuration related to uplink transmission (eg, PUCCH / SRS) and ii) clear the configured downlink assignment, configured uplink grant and / or PUSCH resources.

[0335] As an example, the UE may not perform uplink transmission except for random access preamble transmission and MsgA transmission.

[0336] According to an embodiment, the TAG may include i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index. An embodiment may be based on Proposal 5-1.

[0337] The time alignment timer may include i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG.

[0338] The configuration related to the uplink transmission may be released based on expiration of the first time alignment timer.

[0339] According to an embodiment, the configuration related to uplink transmission may be related to at least one of i) a physical uplink control channel (PUCCH) and / or ii) a sounding reference signal (SRS). This embodiment may be based on proposal 5-1.

[0340] For example, the first TAG may be a primary timing advance group (PTAG) or a secondary timing advance group (STAG). (1) When the first TAG is a PTAG, PUCCH and / or SRS for all serving cells may be released. (2) When the first TAG is a STAG, PUCCH and / or SRS for the serving cell may be released.

[0341] However, regardless of the type (PTAG / STAG) of the TAG (ie, the first TAG) associated with the expired time alignment timer, the above-mentioned release operation based on (1) and (2) may be performed. Hereinafter, the details will be explained.

[0342] As an example, based on the expiration of the first time alignment timer, the PUCCH for i) all serving cells or ii) serving cells belonging to the first TAG may be released.

[0343] As an example, based on the first time alignment timer having expired, the SRS for i) all serving cells or ii) serving cells belonging to the first TAG may be released.

[0344] As an example, based on the expiration of the first time alignment timer, the PUCCH and SRS for i) all serving cells or ii) serving cells belonging to the first TAG may be released.

[0345] According to an embodiment, based on the expiration of the first time alignment timer, at least one of i) a configured downlink assignment, ii) a configured uplink grant, and / or iii) a physical uplink shared channel (PUSCH) resource is cleared. This embodiment may be based on Proposal 5-1. The PUSCH resource may be associated with a semi-persistent CSI report. The serving cell performing the above clearing operation may be the same as the serving cell performing the above release operation.

[0346] As an example, based on the type of the first TAG (PTAG or STAG), a clearing operation may be performed on i) all serving cells (eg, the first TAG is PTAG) or ii) serving cells belonging to the first TAG (eg, the first TAG is STAG).

[0347] As an example, (ie, regardless of the type of the first TAG), the clearing operation may be performed on i) all serving cells or ii) serving cells belonging to the first TAG.

[0348] As an example, based on the expiration of the first time alignment timer,

[0349] At least one of i) configured downlink assignments, ii) configured uplink grants, and / or iii) physical uplink shared channel (PUSCH) resources may be cleared for all serving cells or serving cells belonging to the first TAG.

[0350] According to an embodiment, based on the expiration of the first time alignment timer, uplink transmission other than random access preamble transmission and MsgA transmission may not be performed. At this time, the serving cell on which UL transmission is not performed may be the same as the serving cell on which the above release / clearing operation is performed.

[0351] As an example, based on expiration of the first time alignment timer, uplink transmission except for random access preamble transmission and MsgA transmission may not be performed on all serving cells or serving cells belonging to the first TAG.

[0352] As an example, the serving cell may vary based on the type of the first TAG. Specifically, based on the expiration of the first time alignment timer, uplink transmission other than random access preamble transmission and MsgA transmission may not be performed for all serving cells (e.g., when the first TAG is a PTAG) or serving cells belonging to the first TAG (e.g., when the first TAG is a STAG). According to an embodiment, a second TA associated with a second TAG may be determined based on i) a first TA associated with the first TAG and ii) an offset value. This embodiment may be based on Proposal 5-1.

[0353] According to an embodiment, the method may further include a DCI receiving step and a random access preamble sending step. The DCI receiving step and the random access preamble sending step may be performed after S330.

[0354] In the DCI reception step, the UE receives Downlink Control Information (DCI) from the BS.

[0355] The DCI may include information related to the physical downlink control channel (PDCCH) order. The DCI may include a synchronization signal / physical broadcast channel block index (SSB index) related to the PDCCH order. Here, the SSB index may be an SS / PBCH index of the SS / PBCH block.

[0356] The SSB index associated with the PDCCH order may be included in i) a first SSB group associated with a first CORESET pool index and ii) a second SSB group associated with a second CORESET pool index.

[0357] Each SSB group may be based on the group of Proposal 4-1 above. For example, the first SSB group may include one or more first SSBs belonging to SSB indexes 0 to 31, and the second SSB group may include one or more second SSBs belonging to SSB indexes 32 to 63.

[0358] For example, the DCI may be DCI format 1_0. DCI format 1_0 may include an SS / PBCH index field. The SS / PBCH index field may indicate an SS / PBCH (or SSB index) used to determine a RACH timing for PRACH transmission (ie, random access preamble transmission).

[0359] The random access procedure may be initiated by the PDCCH sequence. As an example, the random access procedure may be initiated by the PDCCH sequence to establish a timing advance for a timing advance group. That is, a DCI related to the PDCCH sequence may be sent from the BS to the UE.

[0360] As an example, the random access procedure may be a type 1 random access procedure (4-step RA) or a type 2 random access procedure (2-step RA).

[0361] The type 1 random access procedure may include sending a random access preamble (Msg1) on a physical random access channel (PRACH), receiving a random access response (RAR) (Msg2), sending a PUSCH scheduled by a UL grant of the RAR (Msg3), and sending a PDSCH for contention resolution (Msg4). When the random access procedure is contention-free random access (CFRA), the Msg3 transmission and Msg4 reception operations are omitted.

[0362] The type 2 random access procedure may include sending a random access preamble and a PUSCH (MsgA) and receiving a RAR (MsgB).

[0363] In the random access preamble transmission step, the UE transmits a random access preamble to the BS. The random access preamble may be transmitted based on a random access procedure (e.g., 4-step RA or 2-step RA) sequentially initiated through the PDCCH. As an example, the random access preamble may be based on Msg1 of a type 1 random access procedure or MsgA of a type 2 random access procedure.

[0364] According to an embodiment, the random access preamble may be transmitted based on an SSB index related to the PDCCH order or a specific SSB index. This embodiment may be based on Proposal 5-2.

[0365] As an example, according to a reference signal received power (RSRP) of an SSB based on an SSB index associated with a PDCCH order being greater than an RSRP threshold,

[0366] The random access preamble may be sent based on an SSB index associated with the PDCCH order.

[0367] The SSBs based on the SSB index associated with the PDCCH order may be associated with contention-free random access (CFRA) resources.

[0368] As an example, according to a reference signal received power (RSRP) of an SSB based on an SSB index associated with a PDCCH order being less than or equal to an RSRP threshold,

[0369] The random access preamble may be sent based on an SSB index within a first SSB group or a second SSB group to which an SSB index associated with a PDCCH order belongs.

[0370] An SSB based on an SSB index within the first SSB group or the second SSB group may be associated with a contention-based random access (CBRA) resource.

[0371] According to an embodiment, the method may further include a timing advance command receiving step. In the timing advance command receiving step, the UE receives a timing advance command from the BS. The timing advance command receiving step may be performed after S330.

[0372] As an example, the timing advance MAC CE may be based on a medium access control element (MAC CE) (e.g., a timing advance MAC CE, Figure 2 ) or MAC RAR ( Figure 1 ) receives the timing advance command.

[0373] According to an embodiment, the timing advance command may be associated with the first TAG or the second TAG. This embodiment may be based on Proposal 5-2.

[0374] For a specific serving cell with a CORESET pool index configured among serving cells (eg CC / BWP) belonging to the first TAG and the second TAG,

[0375] A timing advance (TA) used for uplink timing may be determined as a specific TA.

[0376] The specific TA may be i) a first TA associated with the first TAG or ii) a TA configured for a specific serving cell. The TA configured for a specific serving cell may be configured / defined by the BS or in advance as a first TA associated with the first TAG or a second TA associated with the second TAG.

[0377] According to an embodiment, the timing advance command indicates an index associated with the timing adjustment (see Figure 1 , Table 4 and Table 5). The index related to the timing adjustment may refer to the index value T of Table 4 and Table 5. A The N used to calculate the timing advance (TA) may be indicated based on an index associated with the timing adjustment. TA .

[0378] TA can refer to Table 1 . The TA may be a TRP-specific TA (e.g., a first TA or a second TA). Specifically, the TA may be associated with a first timing advance group (TAG) or a second timing advance group (TAG). The first TAG (or first TAG ID) may be associated with a first CORESET pool index, and the second TAG (or second TAG ID) may be associated with a second CORESET pool index.

[0379] Based on the operations of S310 to S330 above, the DCI receiving step, the random access preamble sending step and the timing advance command receiving step can be performed by Figure 5 For example, the UE 200 may control one or more transceivers 230 and / or one or more memories 240 so as to perform operations based on the above-mentioned operations S310 to S330, the DCI receiving step, the random access preamble sending step, and the timing advance command receiving step.

[0380] Hereinafter, the following embodiments will be specifically described with respect to the operation of the BS.

[0381] S410 to S420, the DCI transmission step, the random access preamble reception step, and the timing advance command transmission step described below correspond to Figure 3 S310 to S330, DCI receiving step, random access preamble sending step and timing advance command receiving step described in the above. By taking into account the corresponding relationship, redundant explanations are omitted. That is, the specific description of the BS operation described below can be used Figure 3 should be replaced with the description / example that corresponds to that operation.

[0382] As an example, Figure 3 The description / embodiment of S310 to S330 may additionally be applied to the BS operations of S410 and S420 described below.

[0383] As an example, the description / embodiment of the DCI receiving step, the random access preamble sending step, and the timing advance command receiving step can be additionally applied to the BS operations of the DCI sending step, the random access preamble receiving step, and the timing advance command sending step described below.

[0384] Figure 4is a flowchart for describing a method performed by a BS in a wireless communication system according to another embodiment of the present disclosure.

[0385] refer to Figure 4 , a method performed by a BS in a wireless communication system according to another embodiment of the present disclosure includes a step of transmitting configuration information related to a CORESET ( S410 ) and a step of transmitting configuration information related to a TAG ( S420 ).

[0386] In S410 , the BS sends configuration information related to a plurality of control resource sets (CORESETs) to the UE.

[0387] In S420, the BS sends configuration information related to a timing advance group (TAG) to the UE. At this time, the configuration related to uplink transmission of the UE may be released based on expiration of a time alignment timer related to the TAG.

[0388] According to an embodiment, the method may further include a DCI transmission step and a random access preamble reception step. The DCI transmission step and the random access preamble reception step may be performed after S420.

[0389] In the DCI transmission step, the BS transmits Downlink Control Information (DCI) to the UE.

[0390] In the random access preamble reception step, the BS receives a random access preamble from the UE.

[0391] According to an embodiment, the method may further include a timing advance command sending step. In the timing advance command sending step, the BS sends a timing advance command to the UE. The timing advance command sending step may be performed after S420.

[0392] The above-mentioned operations based on S410 and S420, the DCI sending step, the random access preamble receiving step and the timing advance command sending step can be performed by Figure 5 For example, the BS 100 may control one or more transceivers 130 and / or one or more memories 140 so as to perform operations based on the above-mentioned operations of S410 and S420, the DCI transmission step, the random access preamble reception step, and the timing advance command transmission step.

[0393] Reference below Figure 5 A device to which an embodiment of the present disclosure is applicable (a device that implements a method / operation according to an embodiment of the present disclosure) is described.

[0394] Figure 5 The configurations of a first device and a second device according to an embodiment of the present disclosure are illustrated.

[0395] The first device 100 may include a processor 110 , an antenna unit 120 , a transceiver 130 , and a memory 140 .

[0396] The processor 110 may perform baseband-related signal processing, and includes a higher layer processing unit 111 and a physical layer processing unit 115. The higher layer processing unit 111 may process operations of a MAC layer, an RRC layer, or a higher layer. The physical layer processing unit 115 may process operations of a PHY layer. For example, if the first device 100 is a base station (BS) device in base station-UE communication, the physical layer processing unit 115 may perform uplink received signal processing, downlink transmitted signal processing, etc. For example, if the first device 100 is a first UE device in inter-UE communication, the physical layer processing unit 115 may perform downlink received signal processing, uplink transmitted signal processing, side link transmitted signal processing, etc. In addition to performing baseband-related signal processing, the processor 110 may also control the overall operation of the first device 100.

[0397] The antenna unit 120 may include one or more physical antennas, and if the antenna unit 120 includes multiple antennas, MIMO transmission / reception is supported. The transceiver 130 may include a radio frequency (RF) transmitter and an RF receiver. The memory 140 may store information processed by the processor 110 and software, an operating system, and applications related to the operation of the first device 100. The memory 140 may also include components such as a buffer.

[0398] The processor 110 of the first device 100 may be configured to implement operations of the BS in BS-UE communication (or operations of the first UE device in inter-UE communication) in the embodiments described in the present disclosure.

[0399] The second device 200 may include a processor 210 , an antenna unit 220 , a transceiver 230 , and a memory 240 .

[0400] The processor 210 may perform baseband-related signal processing and include a higher layer processing unit 211 and a physical layer processing unit 215. The higher layer processing unit 211 may process operations of a MAC layer, an RRC layer, or a higher layer. The physical layer processing unit 215 may process operations of a PHY layer. For example, if the second device 200 is a UE device in BS-UE communication, the physical layer processing unit 215 may perform downlink received signal processing, uplink transmitted signal processing, etc. For example, if the second device 200 is a second UE device in inter-UE communication, the physical layer processing unit 215 may perform downlink received signal processing, uplink transmitted signal processing, side link received signal processing, etc. In addition to performing baseband-related signal processing, the processor 210 may also control the overall operation of the second device 210.

[0401] The antenna unit 220 may include one or more physical antennas, and if the antenna unit 220 includes multiple antennas, MIMO transmission / reception is supported. The transceiver 230 may include an RF transmitter and an RF receiver. The memory 240 may store information processed by the processor 210 and software, an operating system, and applications related to the operation of the second device 200. The memory 240 may also include components such as a buffer.

[0402] The processor 210 of the second device 200 may be configured to implement the operation of the UE in the BS-UE communication (or the operation of the second UE device in the inter-UE communication) in the embodiments described in the present disclosure.

[0403] The description of the BS and the UE in BS-UE communication (or the first UE device and the second UE device in inter-UE communication) in the examples of the present disclosure can be equally applied to the operations of the first device 100 and the second device 200, and redundant description is omitted.

[0404] The wireless communication technology implemented in the devices 100 and 200 according to the present disclosure may include, in addition to LTE, NR, and 6G, a narrowband Internet of Things (NB-IoT) for low-power communication. For example, the NB-IoT technology may be an example of a low-power wide area network (LPWAN) technology and may be implemented in standards such as LTE Cat NB1 and / or LTE Cat NB2. The NB-IoT technology is not limited to the above names.

[0405] Additionally or alternatively, the wireless communication technology implemented in the devices 100 and 200 according to the present disclosure may perform communication based on the LTE-M technology. For example, the LTE-M technology may be an example of an LPWAN technology and may be referred to as various names such as enhanced machine type communication (eMTC). For example, the LTE-M technology may be implemented in at least one of various standards, such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-bandwidth limited), 5) LTE-MTC, 6) LTE machine type communication, and / or 7) LTE M, and is not limited to the above names.

[0406] Additionally or alternatively, in consideration of low power, the wireless communication technology implemented in the devices 100 and 200 according to the present disclosure may include at least one of ZigBee, Bluetooth, and a low power wide area network (LPWAN), and is not limited to the above names. For example, ZigBee technology may generate a PAN (Personal Area Network) related to small / low power digital communication based on various standards such as IEEE 802.15.4, and may be referred to by various names.

Claims

1. A method performed by a user equipment in a wireless communication system, the method comprising: Receiving configuration information related to a plurality of control resource sets (CORESETs), wherein a CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information; receiving configuration information related to a timing advance group (TAG); as well as Based on the expiration of a time alignment timer associated with the TAG, releasing the configuration associated with uplink transmission, The TAG includes i) a first TAG associated with a first CORESET pool index, and ii) a second TAG associated with a second CORESET pool index, The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG, and Wherein, based on the expiration of the first time alignment timer, the configuration related to the uplink transmission is released.

2. The method according to claim 1, wherein: The configuration associated with the uplink transmission is associated with at least one of i) a physical uplink control channel (PUCCH) and / or ii) a sounding reference signal (SRS).

3. The method according to claim 2, wherein: Based on expiration of the first time alignment timer, the PUCCH for i) all serving cells or ii) serving cells belonging to the first TAG is released.

4. The method according to claim 2, wherein: Based on expiration of the first time alignment timer, the SRS for i) all serving cells or ii) the serving cells belonging to the first TAG is released.

5. The method according to claim 1, wherein: Based on expiration of the first time alignment timer, at least one of i) configured downlink assignments, ii) configured uplink grants and / or iii) physical uplink shared channel (PUSCH) resources is cleared for all serving cells or the serving cells belonging to the first TAG.

6. The method according to claim 5, wherein: The PUSCH resource is associated with semi-persistent CSI reporting.

7. The method according to claim 1, wherein: Based on expiration of the first time alignment timer, uplink transmission other than random access preamble transmission and MsgA transmission is not performed on all serving cells or the serving cells belonging to the first TAG.

8. The method according to claim 1, further comprising: receiving downlink control information (DCI), wherein the DCI includes information related to a physical downlink control channel (PDCCH) sequence, and a random access procedure is initiated through the PDCCH sequence; and Send a random access preamble, The DCI includes a synchronization signal / physical broadcast channel block index (SSB index) associated with the PDCCH sequence, and The SSB index associated with the PDCCH sequence is included in i) a first SSB group associated with the first CORESET pool index or ii) a second SSB group associated with the second CORESET pool index.

9. The method according to claim 8, wherein: Based on a reference signal received power (RSRP) of an SSB of the SSB index associated with the PDCCH order being greater than an RSRP threshold, the random access preamble is sent based on the SSB index associated with the PDCCH order.

10. The method according to claim 9, wherein: The SSBs based on the SSB index associated with the PDCCH order are associated with at least one contention free random access (CFRA) resource.

11. The method according to claim 8, wherein: According to the reference signal received power (RSRP) of the SSB based on the SSB index associated with the PDCCH order being equal to or less than an RSRP threshold, the random access preamble is sent based on the SSB index within the first SSB group or the second SSB group to which the SSB index associated with the PDCCH order belongs.

12. The method according to claim 11, wherein: The SSB based on the SSB index within the first SSB group or the second SSB group is associated with at least one contention-based random access (CBRA) resource.

13. The method according to claim 1, wherein: A second TA associated with the second TAG is determined based on i) a first TA associated with the first TAG and ii) an offset value.

14. The method according to claim 1, further comprising: Receiving a timing advance command, The timing advance command is related to the first TAG or the second TAG.

15. The method according to claim 14, wherein: For a specific serving cell in which one CORESET pool index is configured among the serving cells belonging to the first TAG and the second TAG: The timing advance (TA) used for uplink timing is determined to be a specific TA.

16. The method according to claim 15, wherein: The specific TA is i) a first TA related to the first TAG or ii) a TA configured for the specific serving cell.

17. A user equipment operating in a wireless communication system, comprising: one or more transceivers; one or more processors; as well as one or more memories operably connected to the one or more processors and storing instructions that configure the one or more processors to perform operations based on execution by the one or more processors, The operations include: Receiving configuration information related to a plurality of control resource sets (CORESETs), wherein a CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information; receiving configuration information associated with a timing advance group (TAG); and Based on the expiration of the time alignment timer associated with the TAG, releasing the configuration associated with uplink transmission except for the random access preamble and MsgA, The TAG includes i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index, The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG, and Wherein, based on the expiration of the first time alignment timer, the configuration related to the uplink transmission is released.

18. An apparatus comprising: one or more memories and one or more processors, the one or more processors being functionally connected to the one or more memories, wherein the one or more memories include instructions for configuring the one or more processors to perform operations based on execution by the one or more processors, and The operations include: receiving configuration information related to a plurality of control resource sets (CORESETs), wherein a CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information, receiving configuration information related to a Timing Advance Group (TAG), and Based on the expiration of the time alignment timer associated with the TAG, releasing the configuration associated with uplink transmission except for the random access preamble and MsgA, The TAG includes i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index, The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG, and Wherein, based on the expiration of the first time alignment timer, the configuration related to the uplink transmission is released.

19. One or more non-transitory computer-readable media storing one or more instructions, in, The one or more instructions executable by one or more processors configure the one or more processors to perform operations, and The operations include: receiving configuration information related to a plurality of control resource sets (CORESETs), wherein a CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information, receiving configuration information related to a Timing Advance Group (TAG), and Based on the expiration of the time alignment timer associated with the TAG, releasing the configuration associated with uplink transmission except for the random access preamble and MsgA, The TAG includes i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index, The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG, and Wherein, based on the expiration of the first time alignment timer, the configuration related to the uplink transmission is released.

20. A method performed by a base station in a wireless communication system, the method comprising: Sending configuration information related to a plurality of control resource sets (CORESETs), wherein a CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information; and Send configuration information related to the timing advance group (TAG), wherein, based on the expiration of the time alignment timer associated with the TAG, the configuration associated with uplink transmission other than the random access preamble and MsgA is released, The TAG includes i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index, The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG, and Wherein, based on the expiration of the first time alignment timer, the configuration related to the uplink transmission is released.

21. A base station operating in a wireless communication system, comprising: one or more transceivers; one or more processors; as well as one or more memories operably connected to the one or more processors and storing instructions that configure the one or more processors to perform operations based on execution by the one or more processors, The operations include: Sending configuration information related to a plurality of control resource sets (CORESETs), wherein a CORESET based on two different control resource set (CORESET) pool indexes is configured based on the configuration information; and Send configuration information related to the timing advance group (TAG), wherein, based on the expiration of the time alignment timer associated with the TAG, the configuration associated with uplink transmission other than the random access preamble and MsgA is released, The TAG includes i) a first TAG associated with a first CORESET pool index and ii) a second TAG associated with a second CORESET pool index, The time alignment timer includes i) a first time alignment timer associated with the first TAG and ii) a second time alignment timer associated with the second TAG, and Wherein, based on the expiration of the first time alignment timer, the configuration related to the uplink transmission is released.

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