Method and apparatus for cross-TRP random access

Abstract

Methods and apparatus for cross-TRP random access are disclosed. The method performed by the UE comprises the steps of: receiving a cross-PDCCH instruction from a first TRP; identifying a second TRP to perform the RA process, the second TRP being identified on the basis of the first indication information included in the cross-PDCCH instruction; and transmitting a message including the RA preamble to a second TRP, wherein the first TRP and the second TRP are different TRPs.

Description

Technical Field

[0001] This invention relates to a random access technique, and more specifically, to a technique for random access across transmitting and receiving points (TRPs) in a communication system comprising one or more TRPs. Background Technology

[0002] Communication networks (e.g., 5G or 6G networks) are being developed to provide enhanced communication services compared to existing networks (e.g., Long Term Evolution (LTE), LTE-Advanced (LTE-A), etc.). 5G networks (e.g., New Radio (NR) networks) can support frequency bands below and above 6 GHz. In other words, 5G networks can support Frequency Area 1 (FR1) and / or FR2 bands. Compared to LTE networks, 5G networks can support a wider range of communication services and scenarios. For example, use cases for 5G networks can include enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communication (URLLC), and massive Machine Type Communication (mMTC).

[0003] Compared to 5G communication networks, 6G communication networks can support a wide variety of communication services and scenarios. 6G communication networks can meet requirements for superior performance, bandwidth, spatial flexibility, precision, intelligence, and / or reliability. 6G communication networks can support multiple wideband frequencies and can be applied to various use cases, such as terrestrial communication, non-terrestrial communication, and sidelink communication.

[0004] On the other hand, multiple transmission and reception points (mTRPs) can be introduced into communication networks (e.g., 5G and / or 6G networks). mTRPs can be geographically separated. Base stations can utilize mTRPs to communicate with terminals. mTRP technology can be used to address quality of service (QoS) degradation at cell edge terminals and / or inter-cell interference. In environments where non-line-of-sight (NLOS) paths are limited, mTRP technology can be used to provide additional communication paths.

[0005] Communication based on mTRP can be performed using either coherent joint transmission (CJT) or non-CJT (NCJT) schemes. In a CJT scheme, mTRP can perform cooperative communication based on a stable backhaul link and provide synchronous communication services to terminals. In an NCJT scheme, mTRP can provide communication services to terminals without cooperation. For example, in an NCJT scheme, mTRP can perform operations such as scheduling, pre-codec matrix selection, and modulation and coding scheme (MCS) determination without cooperation.

[0006] In mTRP-based communication, the terminal can apply timing advance (TA) to each TRP used for uplink transmission. Uplink transmission can refer to the transmission of UL channels / UL signals. The terminal can acquire the TA by performing a random access (RA) procedure. The random access response (RAR) can include a timing advance command (TAC), and the terminal can acquire the TA based on the TAC included in the RAR. Alternatively, the base station can send a medium access control (MAC) control element (CE) including a TAC to the terminal. The terminal can acquire the TA based on the TAC included in the MAC CE received from the base station.

[0007] In mTRP-based communication, the first TRP can send Physical Downlink Control Channel (PDCCH) commands to the terminal. The terminal can receive PDCCH commands from the first TRP and initiate an RA procedure based on the PDCCH commands. In this case, it may be necessary for the terminal to send the RA preamble to another TRP instead of the first TRP. Specific methods are needed to support the above operations. Summary of the Invention

[0008] Technical issues This invention aims to provide methods and apparatus for random access across TRPs in a communication system comprising one or more TRPs.

[0009] Technical solution A method for a user equipment (UE) according to an exemplary embodiment of the present invention to achieve the above objectives may include: receiving a cross-physical downlink control channel (PDCCH) instruction from a first transmitting and receiving point (TRP); identifying a second TRP as the target of a random access (RA) procedure based on first indication information included in the cross-PDCCH instruction; and sending a message including an RA preamble to the second TRP, wherein the first TRP and the second TRP are different TRPs.

[0010] The first indication information can indicate the timing advance group (TAG) identifier (ID), and the TAG ID can be configured to be associated with the transport configuration indicator (TCI) status.

[0011] The first indication information can indicate the TCI status used for the second TRP.

[0012] The first indication information may indicate a dedicated preamble for the RA process, the dedicated preamble to which the dedicated preamble belongs may be configured to be associated with a control resource set (CORESET) pool, and the CORESET pool may be configured to be associated with a TCI state.

[0013] The first indication information can indicate the random access channel (RACH) timing (RO) used for transmitting messages. The RO group to which the RO belongs can be configured to be associated with the CORESET pool, and the CORESET pool can be configured to be associated with the TCI status.

[0014] The first indication information may indicate a cell identifier (ID), and the second TRP may belong to the cell indicated by the cell ID.

[0015] The message including the RA preamble can be Msg1 in a four-step RA process or MsgA in a two-step RA process.

[0016] The method may further include receiving a Random Access Response (RAR) message as a response to a message from a first TRP or a second TRP, wherein the RAR message may include timing advance (TA) information for the second TRP.

[0017] The UE may expect to receive RAR messages from one of the first TRPs or the second TRP, which is associated with a CORESET pool to which a CORESET is configured with a Type 1 Common Search Space (CSS).

[0018] The RAR message may further include uplink (UL) authorization and a second indication information indicating the transmission destination of Msg3, and Msg3 may be sent to a TRP determined based on the second indication information in either the first TRP or the second TRP.

[0019] A method for a base station according to an exemplary embodiment of the present invention to achieve the above objectives may include: generating a cross-Physical Downlink Control Channel (PDCCH) instruction indicating a second Transmit and Receive Point (TRP) as the target of a Random Access (RA) procedure; and sending the cross-PDCCH instruction to a User Equipment (UE) via a first TRP, wherein, during an RA procedure triggered by the cross-PDCCH instruction, a message including an RA preamble is sent from the UE to the second TRP, and the first TRP and the second TRP are different TRPs connected to the base station.

[0020] The first indication information can indicate the timing advance group (TAG) identifier (ID), and the TAG ID can be configured to be associated with the transport configuration indicator (TCI) status.

[0021] The first indication information can indicate the TCI status used for the second TRP.

[0022] The first indication information may indicate a dedicated preamble for the RA process, the dedicated preamble to which the dedicated preamble belongs may be configured to be associated with a control resource set (CORESET) pool, and the CORESET pool may be configured to be associated with a TCI state.

[0023] The first indication information can indicate the random access channel (RACH) timing (RO) used for transmitting messages. The RO group to which the RO belongs can be configured to be associated with the CORESET pool, and the CORESET pool can be configured to be associated with the TCI status.

[0024] The first indication information may indicate a cell identifier (ID), and the second TRP may belong to the cell indicated by the cell ID.

[0025] The message including the RA preamble can be Msg1 in a four-step RA process or MsgA in a two-step RA process.

[0026] A user equipment (UE) according to an exemplary embodiment of the present invention for achieving the above objectives may include at least one processor, wherein the at least one processor may cause the UE to perform: receiving a cross-physical downlink control channel (PDCCH) instruction from a first transmitting and receiving point (TRP); identifying a second TRP as the target of a random access (RA) procedure based on first indication information included in the cross-PDCCH instruction; and sending a message including an RA preamble to the second TRP, wherein the first TRP and the second TRP are different TRPs.

[0027] The first indication information may indicate at least one of the following: a timing advance group (TAG) identifier (ID) for the second TRP, a transmission configuration indicator (TCI) status for the second TRP, a dedicated preamble for the RA procedure, a random access channel (RACH) timing (RO) for message transmission, or a cell identifier (ID) indicating the cell to which the second TRP belongs.

[0028] At least one processor may further cause the UE to perform: receiving a random access response (RAR) message from a first TRP or a second TRP, the random access response (RAR) message being a response to a message, wherein the RAR message may be received from one of the first TRPs or the second TRP, the first TRP being associated with a control resource set (CORESET) pool to which a CORESET configured with a type 1 common search space (CSS) belongs.

[0029] Beneficial effects According to the present invention, a terminal can receive a cross-PDCCH instruction from a first TRP, identify a second TRP as the target of the RA process based on information included in the cross-PDCCH instruction, and send a message including an RA preamble to the second TRP. Since the second TRP as the target of the RA process can be identified based on information included in the cross-PDCCH instruction, the RA process based on the cross-PDCCH instruction can be executed efficiently. Attached Figure Description

[0030] Figure 1 This is a conceptual diagram illustrating an exemplary implementation of a communication system.

[0031] Figure 2 This is a block diagram illustrating an exemplary implementation of a communication node constituting a communication system.

[0032] Figure 3 This is a block diagram illustrating an exemplary implementation of a communication node performing communication.

[0033] Figure 4a This is a block diagram illustrating an exemplary implementation of the transmission path.

[0034] Figure 4b This is a block diagram illustrating an exemplary implementation of the receiving path.

[0035] Figure 5 This is a conceptual diagram illustrating an exemplary implementation of a system frame in a communication system.

[0036] Figure 6 This is a conceptual diagram illustrating an exemplary implementation of a subframe in a communication system.

[0037] Figure 7This is a conceptual diagram illustrating an exemplary implementation of a time slot in a communication system.

[0038] Figure 8 This is a conceptual diagram illustrating an exemplary implementation of time-frequency resources in a communication system.

[0039] Figure 9 This is a sequence diagram illustrating the CFRA process based on the PDCCH instruction.

[0040] Figure 10 This is a sequence diagram illustrating the CFRA process based on the PDCCH instruction.

[0041] Figures 11 to 15 This is a sequence diagram illustrating the four-step CBRA process based on the PDCCH instruction.

[0042] Figure 16 This is a sequence diagram illustrating the four-step CBRA process based on the PDCCH instruction.

[0043] Figure 17 and Figure 18 This is a sequence diagram illustrating a two-step CBRA process based on the PDCCH instruction.

[0044] Figure 19 This is a sequence diagram illustrating a two-step CBRA process based on the PDCCH instruction. Detailed Implementation

[0045] Because the present invention can be modified in various ways and can take many forms, specific exemplary embodiments will be shown in the accompanying drawings and described in detail in the specific embodiments. However, it should be understood that the present invention is not intended to be limited to the specific exemplary embodiments, but rather, the present invention covers all modifications and alternatives that fall within the spirit and scope of the present invention.

[0046] Relational terms such as first, second, etc., may be used to describe various elements, but these elements should not be limited by the terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the invention, a first component may be named a second component, and a second component may similarly be named a first component. The term "and / or" means any one or a combination of a plurality of related and described items.

[0047] In this invention, "at least one of A and B" can mean "at least one of A or B" or "at least one combination of one or more of A and B". Furthermore, "one or more of A and B" can mean "one or more of A or B" or "one or more combinations of one or more of A and B".

[0048] In this invention, “(re)transmission” can mean “transmission”, “retransmission” or “transmission and retransmission”, “(re)configuration” can mean “configuration”, “reconfiguration” or “configuration and reconfiguration”, “(re)connection” can mean “connection”, “reconnection” or “connection and reconnection”, and “(re)access” can mean “access”, “reaccess” or “access and reaccess”.

[0049] When it is said that one component is "connected" or "connected" to another component, it should be understood that the component is directly "connected" or "connected" to the other component, or that another component may be provided between them. Conversely, when it is said that one component is "directly connected" or "directly linked" to another component, it should be understood that no other component is provided between them.

[0050] The terminology used in this invention is for describing specific exemplary embodiments only and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly specifies otherwise. In this invention, terms such as “comprising” or “having” are intended to indicate the presence of features, quantities, steps, operations, components, parts or combinations thereof described in the specification, but it should be understood that these terms do not exclude the presence or addition of one or more features, quantities, steps, operations, components, parts or combinations thereof.

[0051] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms commonly used in dictionaries and already in dictionaries should be interpreted as having the meaning corresponding to their contextual meaning in this field. In this specification, terms are not necessarily interpreted as having a formal meaning unless explicitly defined.

[0052] In the following description, exemplary embodiments of the invention will be described in detail with reference to the accompanying drawings. In order to facilitate a full understanding of the invention, the same reference numerals refer to the same elements throughout the description of the drawings, and repeated descriptions thereof will be omitted. Operations according to the exemplary embodiments explicitly described herein, as well as combinations of exemplary embodiments, extensions of exemplary embodiments, and / or variations of exemplary embodiments, may be performed. Some operations may be omitted, and the sequence of operations may be changed.

[0053] Even when a method (e.g., signal transmission or reception) performed at a first communication node is described in the exemplary embodiment, the corresponding second communication node can also perform a method (e.g., signal reception or transmission) corresponding to the method performed at the first communication node. In other words, when the operation of a user equipment (UE) is described, the corresponding base station can perform an operation corresponding to the operation of the UE. Conversely, when the operation of a base station is described, the corresponding UE can perform an operation corresponding to the operation of the base station.

[0054] Base stations can be referred to using various terms, such as Node B, Evolved Node B, Next Generation Node B (gNodeB), gNB, equipment, device, node, communication node, base transceiver station (BTS), radio remote head (RRH), transmission reception point (TRP), radio unit (RU), roadside unit (RSU), radio transceiver, access point, access node, etc. User equipment (UE) can be referred to using various terms, such as terminal, equipment, device, node, communication node, end node, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, on-board unit (OBU), etc.

[0055] In this invention, signaling can be one or a combination of two or more of higher-layer signaling, MAC signaling, and physical (PHY) signaling. Messages used for higher-layer signaling can be referred to as "higher-layer messages" or "higher-layer signaling messages." Messages used for MAC signaling can be referred to as "MAC messages" or "MAC signaling messages." Messages used for PHY signaling can be referred to as "PHY messages" or "PHY signaling messages." Higher-layer signaling can refer to the operation of sending and receiving system information (e.g., master information block (MIB), system information block (SIB)) and / or RRC messages. MAC signaling can refer to the operation of sending and receiving MAC control elements (CE). PHY signaling can refer to the operation of sending and receiving control information (e.g., downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI)).

[0056] In this invention, "configuration of an operation (e.g., a transmission operation)" can refer to configuration information required for the operation (e.g., information elements, parameters) and / or signaling indicating information for performing the operation. "Configuration of information elements (e.g., parameters)" can refer to signaling of information elements. In this invention, "signal and / or channel" can refer to a signal, a channel, or both, and "signal" can be used to mean "signal and / or channel".

[0057] The communication network using the exemplary embodiments is not limited to the communication network described below, and the exemplary embodiments can be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, "communication network" may be used interchangeably with the term "communication system".

[0058] Figure 1 This is a conceptual diagram illustrating an exemplary implementation of a communication system.

[0059] like Figure 1As shown, the communication system 100 may include multiple communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. Furthermore, the communication system 100 may further include: a core network (e.g., a serving-gateway (S-GW), a packet data network (PDN) gateway (P-GW), and a mobility management entity (MME)). When the communication system 100 is a 5G communication system (e.g., an NR system), the core network may include access and mobility management functions (AMF), user plane functions (UPF), session management functions (SMF), etc.

[0060] Multiple communication nodes 110 to 130 can support the communication protocols specified in the 3rd Generation Partnership Project (3GPP) standard (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.). Multiple communication nodes 110 to 130 can support the following technologies: Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiplexing (OFDM), Filtered OFDM, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Single Carrier FDMA (SC-FDMA), Non-Orthogonal Multiple Access (NOMA), Generalized Frequency Division Multiplexing (GFDM), and Filter Bank Multicarrier. Technologies such as multi-carrier (FBMC), universal filtered multi-carrier (UFMC), and space division multiple access (SDMA) can be used. Each of the multiple communication nodes can have the following structure.

[0061] Figure 2 This is a block diagram illustrating an exemplary implementation of a communication node constituting a communication system.

[0062] like Figure 2As shown, the communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 connected to a network for performing communication. Furthermore, the communication node 200 may further include an input interface device 240, an output interface device 250, and a storage device 260, etc. Each component included in the communication node 200 can communicate with each other when connected via a bus 270.

[0063] Processor 210 can execute programs stored in at least one of memory 220 and storage device 260. Processor 210 can refer to a central processing unit (CPU), graphics processing unit (GPU), or a dedicated processor that executes methods according to embodiments of the present invention thereon. Each of memory 220 and storage device 260 can be constituted by at least one volatile storage medium and a non-volatile storage medium. For example, memory 220 can include at least one of read-only memory (ROM) and random access memory (RAM).

[0064] Refer again Figure 1 The communication system 100 may include multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. The communication system 100 including base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can be referred to as an "access network". Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 can form a macro cell, and each of the fourth base station 120-1 and the fifth base station 120-2 can form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 can all fall within the cell coverage area of ​​the first base station 110-1. Furthermore, the second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 can all fall within the cell coverage area of ​​the second base station 110-2. Additionally, the fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 can all fall within the cell coverage area of ​​the third base station 110-3. Furthermore, the first terminal 130-1 can fall within the cell coverage area of ​​the fourth base station 120-1, and the sixth terminal 130-6 can fall within the cell coverage area of ​​the fifth base station 120-2.

[0065] Here, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can refer to a Node B, an evolved Node B (eNB), a gNB, an advanced base station (ABS), a high-reliability-base station (HR-BS), a base transceiver station (BTS), a radio base station, a radio transceiver, an access point, an access node, a radio access station (RAS), a mobile multihop relay-base station (MMR-BS), a relay station (RS), an advanced relay station (ARS), a high-reliability-relay station (HR-RS), a home Node B (HNB), a home eNode B (HeNB), a roadside unit (RSU), a radio remote head (RRH), or a transmission point. Points (TP), transmission and reception points (TRP), etc.

[0066] Each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can refer to user equipment (UE), terminal equipment (TE), advanced mobile station (AMS), high reliability-mobile station (HR-MS), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, device, on-board unit (OBU), etc.

[0067] On the other hand, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can operate in the same frequency band or different frequency bands. The multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be interconnected via ideal or non-ideal backhaul and exchange information with each other via ideal or non-ideal backhaul. Furthermore, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be connected to the core network via ideal or non-ideal backhaul. Each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can transmit signals received from the core network to the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6, and transmit signals received from the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 to the core network.

[0068] In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can support multiple-input multiple-output (MIMO) transmission (e.g., single-user MIMO, SU-MIMO, multi-user MIMO, MU-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in unlicensed frequency bands, sidelink communication (e.g., device-to-device (D2D) communication, proximity service (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can perform operations corresponding to the following: operations of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and operations supported by the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2. For example, the second base station 110-2 can transmit signals to the fourth terminal 130-4 in SU-MIMO mode, and the fourth terminal 130-4 can receive signals from the second base station 110-2 in SU-MIMO mode. Alternatively, the second base station 110-2 can transmit signals to the fourth terminal 130-4 and the fifth terminal 130-5 in MU-MIMO mode, and the fourth terminal 130-4 and the fifth terminal 130-5 can receive signals from the second base station 110-2 in MU-MIMO mode.

[0069] The first base station 110-1, the second base station 110-2, and the third base station 110-3 can transmit signals to the fourth terminal 130-4 in CoMP mode, and the fourth terminal 130-4 can receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 in CoMP mode. Furthermore, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can exchange signals with the corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 within its cell coverage area in CA mode. Each of base stations 110-1, 110-2 and 110-3 can control the sidelink communication between the fourth terminal 130-4 and the fifth terminal 130-5. Therefore, the fourth terminal 130-4 and the fifth terminal 130-5 can perform sidelink communication under the control of the second base station 110-2 and the third base station 110-3, respectively.

[0070] On the other hand, communication nodes that perform communication in a communication network can be configured as follows. Figure 3 The communication node shown can be Figure 2 The specific exemplary implementation of the communication node shown is illustrated.

[0071] Figure 3 This is a block diagram illustrating an exemplary implementation of a communication node performing communication.

[0072] like Figure 3 As shown, each of the first communication node 300a and the second communication node 300b can be a base station or a UE. The first communication node 300a can transmit signals to the second communication node 300b. The transmission processor 311 included in the first communication node 300a can receive data (e.g., data unit) from the data source 310. The transmission processor 311 can receive control information from the controller 316. The control information may include at least one of system information, RRC configuration information (e.g., information configured by RRC signaling), MAC control information (e.g., MAC CE), or PHY control information (e.g., DCI, SCI).

[0073] The transmitter processor 311 can generate data symbols by performing data processing operations (e.g., encoding operations, symbol mapping operations, etc.). The transmitter processor 311 can generate control symbols by performing control information processing operations (e.g., encoding operations, symbol mapping operations, etc.). Furthermore, the transmitter processor 311 can generate synchronization / reference symbols for synchronization signals and / or reference signals.

[0074] The Tx MIMO processor 312 can perform spatial processing operations (e.g., pre-coding / decoding operations) on data symbols, control symbols, and / or synchronization / reference symbols. The output of the Tx MIMO processor 312 (e.g., a symbol stream) can be provided to a modulator (MOD) included in transceivers 313a to 313t. The modulator can generate modulated symbols by performing processing operations on the symbol stream, and can generate signals by performing additional processing operations on the modulated symbols (e.g., analog-to-digital conversion, amplification, filtering, up-conversion, etc.). The signals generated by the modulators in transceivers 313a to 313t can be transmitted via antennas 314a to 314t.

[0075] The signal transmitted by the first communication node 300a can be received at antennas 364a to 364r of the second communication node 300b. The signals received at antennas 364a to 364r can be provided to a demodulator (DEMOD) included in transceivers 363a to 363r. The demodulator (DEMOD) can obtain samples by performing signal processing operations (e.g., filtering, amplification, down-conversion, digital conversion, etc.). The demodulator can perform additional processing operations on the samples to obtain symbols. MIMO detector 362 can perform MIMO detection operations on the symbols. Receiver processor 361 can perform symbol processing operations (e.g., deinterleaving, decoding, etc.). The output of receiver processor 361 can be provided to data sink 360 and controller 366. For example, data can be provided to data sink 360, and control information can be provided to controller 366.

[0076] On the other hand, the second communication node 300b can send signals to the first communication node 300a. The transmitting processor 368 included in the second communication node 300b can receive data (e.g., data units) from the data source 367 and perform data processing operations to generate data symbols. The transmitting processor 368 can receive control information from the controller 366 and perform control information processing operations to generate control symbols. Furthermore, the transmitting processor 368 can generate reference symbols by performing processing operations on reference signals.

[0077] The Tx MIMO processor 369 can perform spatial processing operations (e.g., pre-coding / decoding operations) on data symbols, control symbols, and / or reference symbols. The output of the Tx MIMO processor 369 (e.g., a symbol stream) can be provided to a modulator (MOD) included in transceivers 363a to 363t. The modulator can generate modulated symbols by performing processing operations on the symbol stream, and can generate signals by performing additional processing operations on the modulated symbols (e.g., analog-to-digital conversion, amplification, filtering, up-conversion). The signals generated by the modulators in transceivers 363a to 363t can be transmitted via antennas 364a to 364t.

[0078] The signal transmitted by the second communication node 300b can be received at antennas 314a to 314r of the first communication node 300a. The signals received at antennas 314a to 314r can be provided to a demodulator (DEMOD) included in transceivers 313a to 313r. The demodulator can obtain samples by performing signal processing operations (e.g., filtering, amplification, down-conversion, digital conversion). The demodulator can perform additional processing operations on the samples to obtain symbols. The MIMO detector 320 can perform MIMO detection operations on the symbols. The receiver processor 319 can perform symbol processing operations (e.g., deinterleaving, decoding, etc.). The output of the receiver processor 319 can be provided to a data sink 318 and a controller 316. For example, data can be provided to the data sink 318, and control information can be provided to the controller 316.

[0079] Memory 315 and memory 365 can store data, control information, and / or program code. Scheduler 317 can perform scheduling operations for communication. Figure 3 The processors 311, 312, 319, 361, 368, and 369 shown, as well as the controllers 316 and 366, can be... Figure 2 The processor 210 shown can be used to perform the methods described in this invention.

[0080] Figure 4a This is a block diagram illustrating an exemplary implementation of the transmission path. Figure 4b This is a block diagram illustrating an exemplary implementation of the receiving path.

[0081] like Figure 4a and Figure 4b As shown, a transmission path 410 can be implemented in the communication node transmitting the signal, and a reception path 420 can be implemented in the communication node receiving the signal. Transmission path 410 may include: a channel coding and modulation block 411, a serial-to-parallel (S-to-P) block 512, an N-point inverse fast Fourier transform (NIFFT) block 413, a parallel-to-serial (P-to-S) block 414, a cyclic prefix (CP) addition block 415, and an up-converter (UC) 416. Reception path 420 may include a down-converter (DC) 421, a CP removal block 422, an S-to-P block 423, an N-point FFT block 424, a P-to-S block 425, and a channel decoding and demodulation block 426. Here, N can be a natural number.

[0082] In the transmission path 410, information bits can be input to the channel coding and modulation block 411. The channel coding and modulation block 411 can perform coding operations on the information bits (e.g., low-density parity check (LDPC) coding, polar coding, etc.) and modulation operations (e.g., Quadrature Phase Shift Keying (OPSK), Quadrature Amplitude Modulation (QAM), etc.). The output of the channel coding and modulation block 411 can be a sequence of modulation symbols.

[0083] S-to-P block 412 can convert frequency-domain modulation symbols into parallel symbol streams to generate N parallel symbol streams. N can be of IFFT size or FFT size. N-point IFFT block 413 can generate a time-domain signal by performing IFFT operations on the N parallel symbol streams. P-to-S block 414 can convert the output of N-point IFFT block 413 (e.g., a parallel signal) into a serial signal to generate a serial signal.

[0084] The CP adder block 415 inserts a CP into the signal. The UC 416 upconverts the frequency of the output of the CP adder block 415 to a radio frequency (RF) frequency. Furthermore, the output of the CP adder block 415 can be filtered in baseband before upconversion.

[0085] The signal transmitted from the transmit path 410 can be input to the receive path 420. The operation in the receive path 420 can be the reverse operation of the operation in the transmit path 410. DC 421 can downconvert the frequency of the received signal to the baseband frequency. CP removal block 422 can remove CP from the signal. The output of CP removal block 422 can be a serial signal. S to P block 423 can convert the serial signal into a parallel signal. N-point FFT block 424 can generate N parallel signals by performing an FFT algorithm. P to S block 425 can convert the parallel signals into a modulation symbol sequence. Channel decoding and demodulation block 426 can perform demodulation operations on the modulation symbols and can recover the data by performing decoding operations on the results of the demodulation operations.

[0086] exist Figure 4a and Figure 4b In this context, the Discrete Fourier Transform (DFT) and the Inverse DFT (IDFT) can be used instead of the FFT and IFFT. Figure 4a and Figure 4bEach of the blocks (e.g., components) in the code can be implemented through at least one of hardware, software, or firmware. For example, Figure 4a and Figure 4b Some blocks can be implemented in software, while others can be implemented in hardware or a combination of hardware and software. Figure 4a and Figure 4b In this system, a block can be subdivided into multiple blocks, multiple blocks can be combined into one block, some blocks can be omitted, and blocks that support other functions can be added.

[0087] Figure 5 This is a conceptual diagram illustrating an exemplary implementation of a system frame in a communication system.

[0088] like Figure 5 As shown, time resources in a communication system can be divided based on frames. For example, system frames in a communication system can be configured consecutively in the time domain. The length of a system frame can be 10 milliseconds (ms). The system frame number (SFN) can be set to one from #0 to #1023. In this case, 1024 system frames can be repeated in the time domain of the communication system. For example, the SFN of a system frame after system frame #1023 can be #0.

[0089] A system frame can include two half-frames. The length of a half-frame can be 5ms. The half-frame located at the beginning of the system frame can be called "half-frame #0," and the half-frame located at the end of the system frame can be called "half-frame #1." A system frame can include 10 subframes. The length of a subframe can be 1ms. The 10 subframes within a system frame can be called subframes #0 to #9.

[0090] Figure 6 This is a conceptual diagram illustrating an exemplary implementation of a subframe in a communication system.

[0091] like Figure 6 As shown, a subframe can include n time slots, where n can be a natural number. Accordingly, a subframe can consist of one or more time slots.

[0092] Figure 7 This is a conceptual diagram illustrating an exemplary implementation of a time slot in a communication system.

[0093] like Figure 7 As shown, a time slot can include one or more symbols. For example, Figure 7 A time slot, as shown, can include 14 symbols. The length of a time slot can vary depending on the number and length of the symbols included. Alternatively, the length of a time slot can vary based on a set of parameters (numerology).

[0094] The parameter set of physical signals and channels applied in a communication system can be variable. The parameter set can be adjusted to meet various technical requirements of the communication system. In a communication system applying OFDM waveform technology based on cyclic prefix (CP), the parameter set may include subcarrier spacing and CP length (or CP type). Table 1 illustrates a first exemplary embodiment of a method for configuring the parameter set of a CP-OFDM-based communication system. Depending on the frequency band in which the communication system operates, at least some of the parameter sets in Table 1 can be supported. Additionally, the communication system can support parameter sets not listed in Table 1.

[0095] [Table 1] When the subcarrier spacing is 15 kHz (e.g., μ=0), the time slot length can be 1 ms. In this case, a system frame can include 10 time slots. When the subcarrier spacing is 30 kHz (e.g., μ=1), the time slot length can be 0.5 ms. In this case, a system frame can include 20 time slots.

[0096] When the subcarrier spacing is 60 kHz (e.g., μ=2), the slot length can be 0.25 ms. In this case, a system frame can include 40 slots. When the subcarrier spacing is 120 kHz (e.g., μ=3), the slot length can be 0.125 ms. In this case, a system frame can include 80 slots. When the subcarrier spacing is 240 kHz (e.g., μ=4), the slot length can be 0.0625 ms. In this case, a system frame can include 160 slots.

[0097] Symbols can be configured as downlink (DL) symbols, flexible (FL) symbols, or uplink (UL) symbols. A time slot consisting only of DL symbols can be called a "DL time slot", a time slot consisting only of FL symbols can be called a "FL time slot", and a time slot consisting only of UL symbols can be called a "UL time slot".

[0098] The slot format can be configured semi-statically via higher-layer signaling (e.g., RRC signaling). Information indicating the semi-static slot format can be included in the system information, and the semi-static slot format can be configured to be cell-specific. Additionally, the semi-static slot format can be further configured for each terminal via terminal-specific higher-layer signaling (e.g., RRC signaling). Flexible symbols in the cell-specific slot format can be overridden as downlink or uplink symbols via terminal-specific higher-layer signaling. Furthermore, the slot format can be dynamically indicated via physical layer signaling (e.g., slot format indicator (SFI) included in the DCI). The semi-statically configured slot format can be overridden by the dynamically indicated slot format. For example, the semi-statically configured flexible symbols can be overridden as downlink or uplink symbols by the SFI.

[0099] Reference signals may include Channel State Information-Reference Signal (CSI-RS), Sounding Reference Signal (SRS), Demodulation-Reference Signal (DM-RS), and Phase Tracking-Reference Signal (PT-RS). Channels may include Physical Broadcast Channel (PBCH), Physical Downlink Control Channel (PDCCH), Physical Downlink Shared Channel (PDSCH), Physical Uplink Control Channel (PUCCH), Physical Uplink Shared Channel (PUSCH), Physical Sidelink Control Channel (PSCCH), and Physical Sidelink Shared Channel (PSSCH). In this invention, the control channel may refer to PDCCH, PUCCH or PSCCH, and the data channel may refer to PDSCH, PUSCH or PSSCH.

[0100] Figure 8 This is a conceptual diagram illustrating an exemplary implementation of time-frequency resources in a communication system.

[0101] like Figure 8 As shown, a resource consisting of one OFDM symbol on the time axis and one subcarrier on the frequency axis can be defined as a "resource element (RE)". A resource consisting of one OFDM symbol on the time axis and K subcarriers on the frequency axis can be defined as a "resource element group (REG)". A REG can include K REs. A REG can be used as the basic unit for resource allocation in the frequency domain. K can be a natural number. For example, K can be 12. N can be a natural number. Figure 7 In the time slot shown, N can be 14. N OFDM symbols can be used as the basic unit for resource allocation in the time domain.

[0102] In this invention, RB can refer to a common RB (CRB). Alternatively, RB can refer to a physical RB (PRB) or a virtual RB (VRB). In a communication system, CRB can refer to an RB that constitutes a set of consecutive RBs (e.g., a common RB grid) based on a reference frequency (e.g., point A). Carrier and / or bandwidth portions can be mapped onto the common RB grid. That is, carrier and / or bandwidth portions can be configured with CRBs. The RB or CRB constituting the bandwidth portion can be referred to as a PRB, and the CRB index can be appropriately converted to a PRB index within the bandwidth portion.

[0103] Downlink data can be transmitted via PDSCH. The base station can send PDSCH configuration information (e.g., scheduling information) to the terminal via PDCCH. The terminal can obtain PDSCH configuration information by receiving PDCCH (e.g., Downlink Control Information (DCI)). For example, PDSCH configuration information may include the modulation and coding scheme (MCS) for PDSCH transmission / reception, PDSCH timing resource information, PDSCH frequency resource information, and PDSCH feedback resource information. PDSCH can refer to the radio resources for transmitting and receiving downlink data. Alternatively, PDSCH can refer to the downlink data itself. PDCCH can refer to the radio resources for transmitting and receiving downlink control information (e.g., DCI). Alternatively, PDCCH can refer to the downlink control information itself.

[0104] The terminal can perform monitoring operations on the PDCCH to receive PDSCH transmitted from the base station. The base station can use higher-layer messages (e.g., Radio Resource Control (RRC) messages) to notify the terminal of configuration information for PDCCH monitoring operations. The configuration information for PDCCH monitoring operations may include Control Resource Set (CORESET) information and search space information.

[0105] CORESET information may include PDCCH demodulation reference signal (DMRS) information, PDCCH pre-coding / decoding information, and PDCCH timing information. The PDCCH DMRS can be the DMRS used for demodulating the PDCCH. PDCCH timing refers to the region where the PDCCH may potentially exist, meaning it is a region where DCI can be transmitted. PDCCH timing can also be called a PDCCH candidate. PDCCH timing information may include time resource information and frequency resource information for the PDCCH timing. In the time domain, the length of the PDCCH timing can be indicated in symbols. In the frequency domain, the size of the PDCCH timing can be indicated in RB units (e.g., PRB units or CRB units).

[0106] Search space information may include a CORESET identifier (ID) associated with the search space, the periodicity of PDCCH monitoring, and / or the offset of PDCCH monitoring. The periodicity and offset of PDCCH monitoring may each be indicated in time slots. Additionally, the search space information may further include an index of the symbol at which the PDCCH monitoring operation began.

[0107] A base station can configure a Bandwidth Part (BWP) for downlink communication. Each terminal can be configured with a different BWP. The base station can use higher-layer signaling to notify the terminal of the BWP configuration information. Higher-layer signaling can refer to the transmission of system information and / or the transmission of RRC messages. A single terminal can have one or more BWPs configured. The terminal can receive BWP configuration information from the base station and identify the configured BWP based on the received configuration information. When multiple BWPs are configured for downlink communication, the base station can activate one or more of the multiple BWPs. The base station can send the configuration information of the activated BWP to the terminal using at least one of higher-layer signaling, a Medium Access Control (MAC) control element (CE), or a DCI. The base station can use the activated BWP to perform downlink communication. The terminal can identify the activated BWP by receiving configuration information from the base station and perform downlink reception operations on the activated BWP.

[0108] On the other hand, communication systems (e.g., NR, 5G, or 6G communication systems) can support use cases such as enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC). Communication systems (e.g., communication networks) can support transmission and reception point (TRP) technologies (e.g., multi-TRP (mTRP) and / or single TRP (sTRP) technologies). Communication systems supporting TRP technologies can be referred to as TRP systems (e.g., mTRP systems and / or sTRP systems). In this invention, "TRP" can have meanings including "sTRP" and / or "mTRP," and depending on the context, "TRP" can refer to either "sTRP" or "mTRP." TRP can refer to an antenna set, antenna group, and / or antenna array. TRP can be associated with CORESET and / or beams (e.g., beam groups).

[0109] mTRP technology can be categorized under MIMO technology. mTRP can possess characteristics of macro cells, small cells, pico cells, and / or femto cells (e.g., cell-level characteristics). mTRP can perform data transmission for terminals. In cases where there are channels with non-uniform channel conditions (e.g., links) due to obstacles and / or interference, mTRP can mitigate the effects caused by obstacles and / or interference. mTRP can improve the data transmission rate of terminals located at the cell edge.

[0110] mTRP-based communication can be performed using either coherent joint transmission (CJT) or non-coherent joint transmission (NCJT). In CJT, the base station knows the channel information between each TRP and the terminal and can perform preprocessing operations on the data based on this information. However, this can increase overhead due to the transmission of channel information and potentially introduce synchronization constraints between TRPs. In NCJT, the base station may not need to know the channel information between each TRP and the terminal. The mTRP can then send data to the terminal without performing preprocessing operations such as phase compensation. The complexity of the NCJT scheme is generally lower than that of the CJT scheme.

[0111] NCJT-based mTRP communication can be performed using either a single DCI scheme or a multi-DCI scheme. In a single DCI scheme, PDSCH transmitted by an mTRP can be scheduled by a single DCI. A single DCI can be transmitted by one TRP of the mTRP. In a multi-DCI scheme, PDSCH transmitted by each TRP can be scheduled using the DCI transmitted by the corresponding TRP. For example, a first PDSCH transmitted by a first TRP can be scheduled using a first DCI transmitted by the first TRP, and a second PDSCH transmitted by a second TRP can be scheduled using a second DCI transmitted by the second TRP. In other words, multiple DCIs can be used to schedule multiple PDSCHs.

[0112] In a single DCI scheme, a terminal may expect to receive PDSCH transmitted by different TRPs through different layers while utilizing the same time and frequency resources. Alternatively, the terminal may expect to receive PDSCH transmitted by different TRPs through different time resources (e.g., different time zones) while utilizing the same frequency resources and the same layer. Alternatively, the terminal may expect to receive PDSCH transmitted by different TRPs through different frequency resources (e.g., different frequency zones) while utilizing the same time resources and the same layer.

[0113] In a multi-DCI scheme, PDSCH scheduling for each TRP can be performed by a separate DCI. PDSCHs scheduled by multiple DCIs can completely or partially overlap. Alternatively, PDSCHs scheduled by multiple DCIs can be non-overlapping. In both single-DCI and multi-DCI schemes, the DCI may include transmission configuration indicator (TCI) status information for PDSCHs.

[0114] The indication / configuration of the TCI state for a terminal can be interpreted as the indication / configuration of a beam (e.g., transmit beam and / or receive beam). In other words, the TCI state can have a meaning corresponding to a beam. From the perspective of downlink (DL) communication, the configuration of the TCI state can refer to the configuration of quasi co-location (QCL). From the perspective of uplink (UL) communication, the configuration of the TCI state can refer to the configuration of a spatial filter. A unified TCI state can indicate (e.g., configure) a common beam, independent of DL and UL communication. Alternatively, a unified TCI state can indicate (e.g., configure) a common beam for each of DL and UL communication. The unified TCI can be referred to as "UTCI".

[0115] To enhance the reliability and / or robustness of mTRP communication, improvements such as PDCCH enhancement can be applied. Deployment scenarios for PDCCH enhancement can be categorized into single-frequency networks (SFN) and non-SFN.

[0116] In the SFN scheme, different TRPs or different panels can utilize the same resources (e.g., the same time resources, the same frequency resources, and / or the same spatial resources) to transmit the same PDCCH. In other words, all TRPs or all panels can utilize the same DMRS configuration, the same DMRS location, and / or the same DMRS sequence to transmit the PDCCH. In this case, from the receiving perspective of the TRP or panel, the TCI states can be implicitly configured differently. The exemplary implementation described above can be performed based on multiple TCI states of CORESET. Synchronization constraints between TRPs for ideal or near-ideal backhaul can exist.

[0117] In the NSFN scheme, the PDCCH generated by the corresponding TRP can be multiplexed in the time and / or frequency domains, and the multiplexed PDCCH can be sent to the terminal. This scheme can be a PDCCH repetition scheme based on mTRP. In the NSFN scheme, the number of encoded bits can be divided between TRPs equal to the number of bits delivered by a PDCCH generated in each TRP, and TRP-specific bits (e.g., encoded bits) can be transmitted through different PDCCH candidates for each TRP. This scheme can correspond to a PDCCH transmission scheme based on sTRP.

[0118] In a mTRP-based PDCCH repetition scheme, PDCCHs can be replicated according to the number of TRPs and can be transmitted within the same search space (e.g., search spaces with the same index) in different search space sets, each with the same number of PDCCH candidates. In this case, the search space sets can exist within the same CORESET or different CORESETs. Since a TCI state can be associated with each CORESET, when PDCCHs are transmitted from different search spaces within the same CORESET, only one TCI state of the PDCCHs transmitted from different search spaces can be indicated (e.g., configured). In this scenario, the terminal can receive one PDCCH from a TRP at a specific time.

[0119] When PDCCHs are transmitted from the same search space within different CORESETs, the terminal implicitly expects to receive PDCCHs from either sTRP or mTRP based on the number of TCI states (e.g., TCI states indicated or configured by the base station). In this case, a single PDCCH can be partitioned into as many PDCCHs as the number of TRPs, and the partitioned PDCCHs can be transmitted in different PDCCH candidates. In this case, the aggregation level and the aggregation level of the combination can be the same. In the exemplary embodiment described above, PDCCH candidates can be assigned to different CORESETs. The payload size of the combination of PDCCHs used for final distribution can be the same as the payload size of the PDCCHs transmitted from sTRP. Accordingly, from the perspective of decoding complexity, the sTRP-based PDCCH transmission scheme can be more advantageous than the mTRP-based PDCCH repetition scheme.

[0120] The terminal can perform mTRP communication or sTRP communication with the base station. mTRP communication between the terminal and the base station can be performed via an mTRP associated with the base station. sTRP communication between the terminal and the base station can be performed via an sTRP associated with the base station. mTRP communication can be referred to as first TRP communication, and sTRP communication can be referred to as second TRP communication. Alternatively, mTRP communication can be referred to as second TRP communication, and sTRP communication can be referred to as first TRP communication. The statement "the terminal performs first TRP communication with the base station" can mean that the terminal performs mTRP communication or sTRP communication with the base station via one or more TRPs associated with the base station. The statement "the terminal performs second TRP communication with the base station" can mean "the terminal performs sTRP communication or mTRP communication with the base station via one or more TRPs associated with the base station."

[0121] In a communication system, a unified TCI framework can be supported. The base station can use RRC signaling to send TCI state pool information (e.g., a pool list) to the terminal. The terminal can receive TCI state pool information (e.g., a pool list) via the base station's RRC signaling. The base station can configure TCI state type information for the terminal. The type information can indicate a combined DL / UL beam indication or a separate DL / UL beam indication. A combined DL / UL beam indication can be referred to as a "combined indication" or "combined type." A separate DL / UL beam indication can be referred to as a "separate indication" or "separate type."

[0122] When configuring a joint type (e.g., joint indication), TCI states for DL ​​and UL can be configured (e.g., a single TCI state). In other words, the DL TCI state configuration and the UL TCI state configuration can be the same. The terminal can expect the TCI state indicated by the information element included in the PDSCH configuration information to be applied to both DL (e.g., DL signal / channel) and UL (e.g., UL signal / channel). The term "signal / channel" can refer to a signal and / or a channel. When configuring a separate type (e.g., separate indication), TCI states for DL ​​and UL can be configured separately. In other words, the DL TCI state configuration can be distinguished from the UL TCI state configuration. The terminal can expect the UL TCI state indicated by the information element included in the UL BWP configuration information to be applied to UL (e.g., UL signal / channel). UL signal / channel can include PUSCH, PUCCH, and / or SRS.

[0123] After configuring (e.g., indicating) a TCI state pool (e.g., a pool list) via RRC signaling, the base station can utilize DCI (e.g., DCI signaling) to indicate TCI states (e.g., the application of TCI states). Due to constraints on the DCI size (e.g., the bits of the DCI field), the base station can preferentially activate candidate TCI states using MAC signaling (e.g., MAC CE signaling). In other words, candidate TCI states can be preferentially activated via MAC CE up to a specific number (e.g., a maximum number) that can be indicated or configured via DCI.

[0124] For an active candidate TCI state, depending on the TCI state type (e.g., combined or separate), the DCI can include code point values ​​corresponding to a single TCI state or two TCI states. When the combined type is configured, the DCI can deliver code point values ​​corresponding to a single TCI state. When the separate type is configured, the DCI can deliver code point values ​​corresponding to two TCI states.

[0125] On the other hand, intra-cell mTRPs or inter-cell mTRPs can support RA procedures based on cross-PDCCH instructions. RA procedures can be classified as contention-free random access (CFRA) procedures and / or contention-based random access (CBRA) procedures. During signaling procedures for cross-TRP RA, indication of the TCI state may be necessary for sending and receiving signals between the terminal and the TRP. In this invention, the term "signal" can refer to either a signal or a channel. Additionally, the term "signal" can be used to encompass "signal + channel". In a cross-PDCCH instruction-based RA procedure, the terminal can receive PDCCH instructions from the first TRP, and based on the PDCCH instructions, the terminal can send an RA preamble to the second TRP. In other words, the terminal can execute an RA procedure initiated by the PDCCH instructions of the first TRP together with the second TRP. PDCCH instructions used for cross-PDCCH instruction-based RA procedures can be referred to as cross-PDCCH instructions. In this invention, depending on the context, a PDCCH instruction can be interpreted as a cross-PDCCH instruction. The RA process can be a four-step RA process or a two-step RA process.

[0126] For the RA procedure between the terminal and the TRP, the terminal may be instructed (e.g., configured) with information about the beam used for communication between the terminal and the TRP (e.g., TCI status indication) before the RA procedure is executed. During the RA procedure, signals (e.g., messages) may be transmitted and received via different TRPs. In this case, the additional TCI status indication may be necessary for signal transmission and reception. In other words, the signaling method for TCI status indication may be necessary for cross-TRP RA operation. Besides the signaling method for TCI status indication, signaling methods for other information may also be necessary for cross-TRP operation.

[0127] Synchronization Signal Block (SSB) transmission configuration, Random Access Timing (RO) configuration, and / or association configuration between SSBs and ROs (e.g., association configuration for beaming information) can be configured in a cell-specific manner (e.g., indicating, operating). Because the configuration operates in a cell-specific manner, in an mTRP system (e.g., an mTRP communication system), the terminal may not be able to identify the TRP transmitting the SSB. Previous SSBs can be transmitted via a specific TRP, and the terminal can obtain beaming configuration information for the RO based on the SSB received via that specific TRP. In the above case, the terminal can perform an RA procedure with a second TRP based on a cross-PDCCH instruction received from a first TRP. The cross-PDCCH instruction can indicate RO information. The cross-PDCCH instruction can include beaming configuration information, and the beaming configuration information can be information about the specific TRP (e.g., the first TRP) used to transmit the previous SSB, rather than information about the second TRP that is the target of the RA procedure. In this case, ambiguity regarding the beaming configuration may occur during the RA procedure. The term "RO" can refer to either a physical random access channel (PRACH) timing or a random access channel (RACH) timing.

[0128] In signaling procedures for cross-TRP RA, a signaling method for TCI status indication may be necessary for the RA procedure between the terminal and the TRP. TCI status indication can be used to indicate the TRP that is sending and receiving signals (e.g., messages) with the terminal. TCI status indication can also be used to indicate the TRP that is performing the RA procedure with the terminal. In this invention, a signaling method for cross-TRP RA will be described. The signaling method may include a signaling method for TCI status indication across TRP RA.

[0129] Exemplary embodiments of the present invention can be applied to mTRP communication based on a single DCI and / or mTRP communication based on multiple DCIs. While exemplary embodiments of the present invention have been described based on a communication system comprising two TRPs, exemplary embodiments of the present invention can also be applied to communication systems comprising three or more TRPs. In the present invention, the TRP transmitting a PDCCH instruction indicating the initiation (e.g., execution) of an RA process can be referred to as TRPx (or the first TRP), and the TRP that is the target of the RA process initiated by the PDCCH instruction can be referred to as TRPy (or the second TRP). TRPy can receive an RA preamble from the terminal and can determine (e.g., measure) the timing advance (TA) based on the RA preamble. The TA can be determined by a base station connected to TRPy. TRPx (or the first TRP) and TRPy (or the second TRP) can refer to different TRPs. TRPx and TRPy can be connected to different base stations. Alternatively, TRPx and TRPy can be connected to the same base station. TRPx and TRPy can also refer to the same TRP.

[0130] 1. CFRA procedure based on PDCCH instructions 1.1 Method #1 Figure 9 This is a sequence diagram illustrating the CFRA process based on the PDCCH instruction.

[0131] like Figure 9 As shown, TRPx can send PDCCH instructions to the terminal (S901). The PDCCH instructions can be generated in the base station connected to TRPx. The base station can send the PDCCH instructions to the terminal via TRPx. The PDCCH instructions may include at least one of dedicated preamble information or RO information. The PDCCH instructions may include information indicating the target of the RA procedure (e.g., information indicating TRPy, TCI status indication for TRPy, etc.). The PDCCH instructions may include information indicating that the PDCCH instruction is a cross-PDCCH instruction. The PDCCH instructions may include information indicating that a cross-TRP RA procedure has been initiated.

[0132] The terminal can receive PDCCH instructions from TRPx (S901). The terminal can identify information included in the PDCCH instructions (e.g., indication information), and based on the identified information, the terminal can send a message including an RA preamble (e.g., Msg1 or MsgA) to TRPy (S902). For example, the terminal can generate an RA preamble based on dedicated preamble information included in the PDCCH instructions, and can send the RA preamble to TRPy in the RO indicated by the RO information included in the PDCCH instructions. The RA preamble can be an RA preamble for Msg1 or MsgA. In other words, the terminal can perform a four-step RA procedure or a two-step RA procedure based on the PDCCH instructions.

[0133] Msg1 (or MsgA) can be an RA request message. The transmission of Msg1 (or MsgA) can refer to the transmission of a dedicated RA preamble in a specific time / frequency resource (e.g., RO). TRPy can receive Msg1 (or MsgA) from the terminal (S902). TRPy can generate Msg2 (or MsgB). Msg2 (or MsgB) can be a Random Access Response (RAR) message. TRPy can determine the TA based on Msg1 (or MsgA), and the TA can be included in Msg2 (or MsgB). The TA can be determined at the base station connected to TRPy, not in TRPy itself. TRPy can send Msg2 (or MsgB) to the terminal (S903). In other words, the base station can send Msg2 (or MsgB) to the terminal via TRPy.

[0134] The terminal can receive Msg2 (or MsgB) from TRPy. The terminal can identify information (e.g., TA) included in Msg2 (or MsgB). The terminal can utilize the TA to perform uplink transmissions. Uplink transmissions can be performed on at least one of TRPx or TRPy. In this invention, depending on the context, Msg1 can be interpreted as MsgA, and MsgA can be interpreted as Msg1. Depending on the context, Msg2 can be interpreted as MsgB, and MsgB can be interpreted as Msg2. In other words, the method proposed for the four-step RA process in this invention can be applied in the same or similar way to the two-step RA process, and the method proposed for the two-step RA process in this invention can be applied in the same or similar way to the four-step RA process.

[0135] exist Figure 9In this context, PDCCH commands can be transmitted for the purpose of cross-TRP RA. In other words, PDCCH commands from TRPx can be transmitted for the purpose of performing an RA procedure on TRPy. Alternatively, PDCCH commands from TRPx can be transmitted for the purpose of performing an RA procedure on TRPx. PDCCH commands may explicitly or implicitly include information (e.g., indication information) indicating the TRP (which is the target of the RA procedure initiated by the PDCCH command). PDCCH commands may include TCI status information for communicating with the TRP. When the PDCCH command of TRPx indicates the initiation of an RA procedure on TRPy, the PDCCH command may include indication information (e.g., TCI status information) for the beam of the RA procedure on TRPy (e.g., RA preamble transmission).

[0136] 1.1.1 Instruction Method #1 The PDCCH instruction may include a timing advance group (TAG) identifier (e.g., a TAG ID field) indicating the TRP (which is the target of the RA process initiated by the PDCCH instruction). The TAG ID can be configured to be associated with a TCI state (e.g., UL / joint TCI state or DL / joint TCI state). The UL / joint TCI state can be associated with a CORESET pool index (e.g., ...). CORESETpoolindex In other words, a TCI state can be associated with a CORESET pool. A TAGID can be configured to be associated with a CORESET (or the CORESET pool to which the CORESET belongs). Since CORESET pools can be configured by TRP (e.g., by TCI state), a TRP that is the target of a RA process initiated by a PDCCH instruction can be identified based on the association between the TAG ID and the UL / joint TCI state, or the association between the TAG ID, the UL / joint TCI state, and the CORESET.

[0137] In other words, the TAG ID included in the PDCCH command can indicate the TRP targeted by the RA procedure and / or the TCI state used for the RA procedure. The UL / joint TCI state can be configured to the terminal via base station signaling (e.g., RRC signaling). When the UL / joint TCI state is not configured, the terminal can assume that the TAG ID is associated with the DL / joint TCI state. Reserved bits included in the PDCCH command can be used to indicate the TAG ID. Alternatively, one field (e.g., the frequency domain resource allocation (FDRA) field) or a combination of two or more fields included in the PDCCH command can be used to indicate the TAG ID.

[0138] 1.1.2 Indication Method #2 The PDCCH instruction may include TCI status information (e.g., a TCI field) indicating the TRP (which is the target of the RA procedure initiated by the PDCCH instruction). The TCI status indicated by the TCI status information (e.g., UL / joint TCI status) may be associated with a TAGID and / or a CORESET pool index. The TCI status information included in the PDCCH instruction may indicate the TRP as the target of the RA procedure. The TCI status information included in the PDCCH instruction may indicate the TCI status used for the RA procedure (e.g., signaling for the RA procedure). Reserved bits included in the PDCCH instruction may be used to indicate the TCI status. The TCI status can be configured to the terminal via RRC signaling from the base station, and one or more TCI states can be activated via MAC CE among the TCI states configured via RRC signaling. The TCI status information included in the PDCCH instruction may indicate at least one of the one or more TCI states activated via MAC CE.

[0139] exist Figure 9 During the RA procedure shown, the terminal can perform uplink and / or downlink communication with TRPy. Uplink communication can refer to the transmission of Msg1, and downlink communication can refer to the reception of Msg2. The terminal can perform the RA procedure with TRPy based on the TCI state indicated by indication method #1 or indication method #2. The TCI state indicated by indication method #1 or indication method #2 can be a combined TCI state or a UL TCI state. The UL TCI state can be paired with the DL TCI state.

[0140] 1.1.3 Indication Method #3 The PDCCH instruction may include a TAG ID and TCI status information to indicate the TRP that is the target of an RA procedure initiated by the PDCCH instruction. In other words, the TAG ID and TCI status information can be used to indicate the TRP that is the target of an RA procedure. When a TCI status is associated with two or more TAG IDs, the terminal may not be able to know which TAG is indicated for TA update based solely on the TCI status information. In this case, both the TAG ID and the TCI status information may be necessary to indicate the TRP that is the target of the RA procedure. Similar to or like indication method #1 and / or indication method #2, reserved bits included in the PDCCH instruction can be used to indicate the TAG ID and TCI status information.

[0141] 1.1.4 Indication Method #4 A dedicated preamble for the CFRA procedure can be configured per TRP (e.g., per TCI state). For example, a dedicated preamble group #0 associated with CORESET pool #0 can be configured, and a dedicated preamble group #1 associated with CORESET pool #1 can be configured. Each dedicated preamble group may include one or more dedicated preambles (e.g., one or more RA preambles). The base station can configure (e.g., indicate) the dedicated preamble group #0 associated with CORESET pool #0 and / or the dedicated preamble group #1 associated with CORESET pool #1 via signaling. The terminal can identify the dedicated preamble group #0 associated with CORESET pool #0 and / or the dedicated preamble group #1 associated with CORESET pool #1 configured by the base station. In this invention, the signaling can be at least one of system information (SI) signaling, RRC signaling, MAC CE signaling, or PHY signaling (e.g., DCI).

[0142] The PDCCH instruction can include information indicating the RA preamble (e.g., a dedicated preamble). The terminal can identify the dedicated preamble group to which the RA preamble indicated by the PDCCH instruction belongs. When the dedicated preamble group to which the RA preamble belongs is dedicated preamble group #0, the terminal can perform the CFRA procedure based on the TCI state associated with CORESET pool #0 (which is associated with dedicated preamble group #0). In other words, the terminal can perform the CFRA procedure with the TRP associated with CORESET pool #0 (which is associated with dedicated preamble group #0).

[0143] 1.1.5 Instruction Method #5 ROs (e.g., dedicated ROs) for the CFRA procedure can be configured per TRP (e.g., per TCI state). For example, a dedicated RO group #0 associated with CORESET pool #0 can be configured, and a dedicated RO group #1 associated with CORESET pool #1 can be configured. Each dedicated RO group may include one or more dedicated ROs. The base station can configure (e.g., indicate) the dedicated RO group #0 associated with CORESET pool #0 and / or the dedicated RO group #1 associated with CORESET pool #1 to the terminal via signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal can identify the dedicated RO group #0 associated with CORESET pool #0 and / or the dedicated RO group #1 associated with CORESET pool #1 configured by the base station.

[0144] The PDCCH instruction can include information indicating a RO (e.g., a dedicated RO). The terminal can identify the dedicated RO group to which the dedicated RO indicated by the PDCCH instruction belongs. When the dedicated RO group to which the dedicated RO belongs is dedicated RO group #0, the terminal can perform the CFRA procedure based on the TCI state associated with CORESET pool #0 (which is associated with dedicated RO group #0). In other words, the terminal can perform the CFRA procedure with the TRP associated with CORESET pool #0 (which is associated with dedicated RO group #0).

[0145] 1.1.5 Instruction Method #6 TRPs can belong to different cells. In this case, an inter-cell cross-TRP RA procedure can be performed. TRPs belonging to different cells can have different physical cell identifiers (PCIs). To indicate the TRP that is the target of the RA procedure in the above case, the PDCCH instruction can include the PCI and / or the cell-associated ID (e.g., cell ID). The PCI and / or the cell-associated ID can indicate the TRP that is the target of the RA procedure. The terminal can perform an RA procedure (e.g., RA preamble transmission operation) with a TRP belonging to a cell that has an ID included in the PDCCH instruction.

[0146] An ID (e.g., a PCI and / or a cell-associated ID) can be associated with a PRACH configuration (e.g., a RACH configuration). For example, PRACH configuration information (e.g., RACH configuration information) may include a PCI and / or a cell-associated ID, and a RA procedure can be performed on a TRP indicated by the PCI and / or the cell-associated ID based on the PRACH configuration information. The base station can send the PRACH configuration information to the terminal. The terminal can receive the PRACH configuration information from the base station and can perform a RA procedure with a TRP based on the PRACH configuration information. For example, the terminal can perform a RA procedure with a TRP indicated by an ID included in the PRACH configuration information.

[0147] PRACH configuration information can be associated with one TCI state or two or more TCI states. The base station can indicate (e.g., configure) the association information (e.g., mapping information) between the PRACH configuration information and TCI states to the terminal via signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal can receive the association information between the PRACH configuration information and TCI states from the base station, identify the TCI states associated with the PRACH configuration information, and perform the RA procedure based on the identified TCI states and TRP.

[0148] The base station can configure the mapping relationship between PRACH configuration information and TCI status, the mapping relationship between PRACH configuration information and TAG ID, and / or the mapping relationship between PRACH configuration information, TCI status, and TAG ID. It can also indicate (e.g., configure) information about the mapping relationship to the terminal via signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal can receive information about the mapping relationship from the base station. The base station (e.g., a TRP connected to the base station) can send a PDCCH command to the terminal including TCI status information (e.g., TCI status indication) and / or TAG ID (e.g., TAG ID indication). The TCI status information and / or TAG ID can indicate the TRP as the target of the RA procedure. The terminal can receive the PDCCH command from the base station and can identify the information included in the PDCCH command. The terminal can identify the TRP as the target of the RA procedure based on the TCI status information and / or TAG ID included in the PDCCH command and can perform the RA procedure with the identified TRP.

[0149] Each of instruction methods #1 to #6 can be applied to a CFRA procedure based on cross-PDCCH instructions. A combination of two or more of instruction methods #1 to #6 can be applied to a CFRA procedure based on cross-PDCCH instructions. Modified and / or extended methods of instruction methods #1 to #6 can be applied to a CFRA procedure based on cross-PDCCH instructions.

[0150] Figure 10 This is a sequence diagram illustrating the CFRA process based on the PDCCH instruction.

[0151] like Figure 10 As shown, TRPx can send PDCCH instructions to the terminal (S1001). The PDCCH instructions can be generated in the base station connected to TRPx. The base station can send the PDCCH instructions to the terminal via TRPx. The PDCCH instructions may include at least one of dedicated preamble information or RO information. The PDCCH instructions may include information indicating the target of the RA procedure (e.g., information indicating TRPy, TCI status indication for TRPy, etc.). The PDCCH instructions may include information indicating that the PDCCH instruction is a cross-PDCCH instruction. The PDCCH instructions may include information indicating that a cross-TRP RA procedure has been initiated.

[0152] The terminal can receive PDCCH instructions from TRPx (S1001). The terminal can identify information included in the PDCCH instructions (e.g., indication information), and based on the identified information, the terminal can send a message including an RA preamble (e.g., Msg1 or MsgA) to TRPy (S1002). For example, the terminal can generate an RA preamble based on dedicated preamble information included in the PDCCH instructions, and can send the RA preamble to TRPy in the RO indicated by the RO information included in the PDCCH instructions. The RA preamble can be an RA preamble for Msg1 or MsgA. In other words, the terminal can perform a four-step RA procedure or a two-step RA procedure based on the PDCCH instructions.

[0153] Msg1 (or MsgA) can be a RA request message. The transmission of Msg1 (or MsgA) can refer to the transmission of a dedicated RA preamble in a specific time / frequency resource (e.g., RO). TRPy can receive Msg1 (or MsgA) from the terminal (S1002). TRPy receiving Msg1 can generate the information needed to generate Msg2 (or MsgB). Msg2 (or MsgB) can be a RAR message. The information needed to generate the RAR message can include information about the TA measured by TRPy. TRPy can determine the TA based on Msg1 received from the terminal and can generate TA information including the determined TA. The TA can be determined by a base station connected to TRPy. The information needed to generate the RAR message can include a radionetwork temporary identifier (RNTI) determined by TRPy. The RNTI can be used for the transmission of Msg2.

[0154] The information required to generate a RAR message can be defined as RAR configuration information. TRPy can send RAR configuration information to TRPx (S1003). TRPx can receive RAR configuration information from TRPy (S1003). Step S1003 can be a sharing step of RAR configuration information (e.g., TA information). RAR configuration information may include at least one of TA information, information required to determine the TA, RNTI for the transmission of Msg2, or information required to determine the RNTI for the transmission of Msg2. TRPy can determine the TA based on Msg1 received from the terminal, and can send information about the determined TA to TRPx in step S1003. Alternatively, the TA for the terminal can be determined in TRPx instead of TRPy, and to support the above operations, TRPy can send the information required to determine the TA to TRPx in step S1003. TRPy can determine the RNTI based on the resource information of the RO of the receiving terminal's Msg1, and can send the determined RNTI to TRPx in step S1003. Alternatively, the RNTI for the transmission of Msg2 can be determined in TRPx instead of TRPy, and to support the above operation, TRPy can send the information required for the determination of the RNTI to TRPx in step S1003.

[0155] TRPx can generate Msg2 (or MsgB) based on RAR configuration information received from TRPy, and can send Msg2 to the terminal (S1004). In other words, the base station can send Msg2 to the terminal via TRPx. Msg2 may include TA information for the terminal. For example, TRPx may determine the TA based on information included in the RAR configuration information that is necessary for determining the TA, and may determine the RNTI based on information included in the RAR configuration information that is necessary for determining the RNTI for transmitting Msg2. Msg2 may include TA information for TRPx and / or TA information for TRPy. The terminal can receive Msg2 from TRPx and can identify the information included in Msg2 (e.g., TA information). The terminal can perform uplink communication based on the TA indicated by Msg2.

[0156] In intra-cell mTRP communication, step S1003 (e.g., TA sharing operation) can be performed by a base station connected to the TRP. In inter-cell mTRP communication, step S1003 (e.g., TA sharing operation) can be performed through the interface between base stations connected to the TRP. The TA sharing operation described above can be applied in the same or similar way to exemplary embodiments of the present invention.

[0157] exist Figure 10In this context, a PDCCH instruction can be transmitted to initiate a cross-TRP RA procedure (e.g., an RA procedure for TRPy). Alternatively, a PDCCH instruction can be transmitted to initiate a TRPx RA procedure. The PDCCH instruction may include information (e.g., indication information) indicating the TRP (e.g., TRPx or TRPy) to which the RA procedure is initiated (e.g., executed). The TRP to which the RA procedure is initiated may be explicitly or implicitly indicated by the PDCCH instruction.

[0158] The PDCCH instruction may include information indicating the TRP (e.g., TRPx or TRPy) of the transport entity that is Msg2 (or MsgB). Figure 9 In an exemplary implementation, the target of the RA procedure (e.g., the transmission operation of Msg1) indicated by the PDCCH instruction can be TRPy, and the transmission entity of Msg2 indicated by the PDCCH instruction can be TRPy. Figure 10 In an exemplary implementation, the target of the RA procedure (e.g., the transmission operation of Msg1) indicated by the PDCCH instruction may be TRPy, and the transmission entity of Msg2 indicated by the PDCCH instruction may be TRPx.

[0159] Instruction methods #1 to #6 can each be applied to Figure 10 Exemplary implementations (e.g., CFRA procedures based on PDCCH instructions). Combinations of two or more of the instruction methods #1 to #6 can be applied. Figure 10 Exemplary implementations. Modified and / or extended methods of methods #1 to #6 can be applied. Figure 10 Exemplary implementations.

[0160] exist Figure 10 In the RA process of the exemplary implementation, the terminal can perform uplink transmissions for TRPy. Therefore, the TCI state indicated by indication method #1 or indication method #2 can be a combined / UL TCI state.

[0161] exist Figure 9 Exemplary implementations (hereinafter referred to as RA method #1) and Figure 10An exemplary implementation (hereinafter referred to as RA method #2) can be performed in a communication system. When both RA method #1 and RA method #2 are applicable to the communication system, it may be necessary to indicate the method actually used in RA method #1 and RA method #2. The method actually used in RA method #1 and RA method #2 can be determined based on the configuration of the Type 1 common search space (CSS) associated with the CORESET pool index. The DCI scheduling Msg2 (e.g., a RAR message) during the RA process can be transmitted in the Type 1 CSS. Therefore, Msg2 can be transmitted via the TRP associated with the CORESET pool to which the CORESET with the Type 1 CSS belongs. The terminal can expect to receive Msg2 (e.g., a RAR message) from the TRP associated with the CORESET pool to which the CORESET with the Type 1 CSS belongs. The RA method (e.g., RA method #1 or RA method #2) can be indicated by the Type 1 CSS configuration.

[0162] On the other hand, in a communication system where TRP#0 and TRP#1 exist, the TCI status information for TRP#0 can be associated with CORESET pool #0, and the TCI status information for TRP#1 can be associated with CORESET pool #1. The PDCCH (e.g., PDCCH instruction) of TRP#0 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #0), and the PDCCH of TRP#1 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #1). Each of TRP#0 and TRP#1 can be one of the TRPs described above, TRPx and TRPy. For example, TRP#0 can be TRPx, and TRP#1 can be TRPy. Alternatively, TRP#0 can be TRPy, and TRP#1 can be TRPx.

[0163] In the above scenario, when Type 1 CSS is configured only in the CORESET associated with CORESET pool #0, RAR messages (e.g., Msg2 or MsgB) can be transmitted via TRP #0 only. Conversely, when Type 1 CSS is configured only in the CORESET associated with CORESET pool #1, RAR messages can be transmitted via TRP #1 only. In another example, when Type 1 CSS is configured in CORESETs associated with both CORESET pool #0 and CORESET pool #1, RAR messages can be transmitted via TRP #0 and / or TRP #1. The terminal can identify the TRP transmitting the RAR messages based on the Type 1 CSS configuration and can expect to receive RAR messages from the identified TRP. The TRP transmitting the RAR messages can be determined based on the Type 1 CSS configuration. The actual method used in RA method #1 and RA method #2 can be indicated by the Type 1 CSS configuration.

[0164] In RA method #1 and / or RA method #2, a TRP for transmitting PDCCH instructions (e.g., across PDCCH instructions) can be configured (e.g., indicated). In a communication system where TRP #0 and TRP #1 exist, TCI status information for TRP #0 can be associated with CORESET pool #0, and TCI status information for TRP #1 can be associated with CORESET pool #1. PDCCH (e.g., PDCCH instructions) of TRP #0 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #0), and PDCCH (e.g., PDCCH instructions) of TRP #1 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #1).

[0165] A CORESET (e.g., a CORESET configuration) capable of transmitting PDCCH instructions (e.g., across PDCCH instructions) can be associated with a specific CORESET pool (e.g., a specific CORESET pool index). Depending on the context, a PDCCH instruction can be interpreted as a cross-PDCCH instruction. For example, a base station can be configured to transmit PDCCH instructions (e.g., across PDCCH instructions) through a CORESET associated with CORESET pool #0, and can indicate the configuration to the terminal via signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal can perform monitoring operations (e.g., receiving operations) on the PDCCH instructions in the CORESET according to the configuration.

[0166] Conversely, the base station can be configured to transmit PDCCH instructions (e.g., across PDCCH instructions) through a CORESET associated with CORESET pool #1, and can indicate the configuration to the terminal via signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal can perform monitoring operations (e.g., receiving operations) on the PDCCH instructions in the CORESET according to the configuration. In another example, the base station can be configured to transmit PDCCH instructions (e.g., across PDCCH instructions) through CORESETs associated with CORESET pools #0 and #1, and can indicate the configuration to the terminal via signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal can perform monitoring operations (e.g., receiving operations) on the PDCCH instructions in the CORESET according to the configuration.

[0167] RA method #1 or RA method #2 can be used in the communication system. Both RA method #1 and RA method #2 can be used in the communication system, and a terminal can be instructed to use the actual RA method. The RA method used can vary depending on the communication scenario (e.g., the communication environment). For example, in an inter-cell mTRP scenario, RA method #1 (e.g., ...) can be applied. Figure 9 (Exemplary implementation), and in inter-cell mTRP scenarios, RA method #2 can be applied (e.g., Figure 10 (Exemplary implementation).

[0168] 2. CBRA procedure based on PDCCH instructions A CBRA procedure can be an RA procedure initiated by the terminal. To support cross-TRP RA procedures, a CBRA procedure based on cross-PDCCH instructions can be supported (e.g., operation). When a dedicated preamble is not configured to the terminal, a CBRA procedure can be executed instead of a CFRA procedure. The terminal can obtain TA information for a specific TRP by executing a CBRA procedure. Information may be needed to execute an RA procedure with a specific TRP to support the above operation. Similar to or similar to the CFRA procedure based on cross-PDCCH instructions described above, a CBRA procedure can be executed based on a specific trigger signal. Similar to or similar to the CFRA procedure based on cross-PDCCH instructions described above, the specific trigger signal used for the CBRA procedure can be defined as a PDCCH instruction. The PDCCH instruction in a CBRA procedure based on cross-PDCCH instructions can be the same as the PDCCH instruction in a CFRA procedure based on cross-PDCCH instructions. Alternatively, the PDCCH instruction in a CBRA procedure based on cross-PDCCH instructions can be a modified or extended form of the PDCCH instruction in a CFRA procedure based on cross-PDCCH instructions.

[0169] The PDCCH instruction used for a CBRA procedure based on cross-PDCCH instructions may include a TAGID associated with a specific TRP to indicate a measurement for the TA of that specific TRP. To provide information about the RO associated with the TRP (e.g., RO configuration information), the PDCCH instruction may include RO information. The PDCCH instruction may include configuration information of SSBs (e.g., SSB groups) transmitted by the TRP. The terminal can receive SSBs based on the SSB configuration information and can identify the ROs associated with the SSBs. The ROs can be determined based on the measurement results of the SSBs. The terminal can receive PDCCH instructions from the TRP and can execute an RA procedure initiated (e.g., triggered) by the PDCCH instruction. The terminal can execute a four-step RA procedure or a two-step RA procedure. During the RA procedure, the terminal may send Msg1 or MsgA to the TRP that is the measurement target of the TA. The PDCCH instruction may include TCI status information for the RA procedure with the TRP that is the measurement target of the TA. TCI status information can be provided to the terminal to indicate information about the beam used for the transmission of the RA preamble (e.g., Msg1 or MsgA) during the RA process.

[0170] A TAG ID can be associated with a joint / UL TCI status. In this case, the TAG ID and / or TCI status information (e.g., TCI status indication) can be used to indicate the TRP as the target of the RA procedure and / or information about the beam used to send the RA preamble to the TRP. PDCCH instructions may include the TAG ID and / or TCI status information.

[0171] TCI status information can be explicitly or implicitly indicated by PDCCH instructions. During a CBRA procedure based on cross-PDCCH instructions, the terminal can perform the RA procedure without performing SSB reception operations (e.g., beam-scan-based SSB reception operations) and can obtain TA information through the RA procedure.

[0172] 2.1 Four-Step CBRA Process Figures 11 to 15 This is a sequence diagram illustrating the four-step CBRA process based on the PDCCH instruction.

[0173] like Figures 11 to 15 As shown, the four-step CBRA process can be triggered (e.g., initiated) by a cross-PDCCH instruction. The messages transmitted during the four-step CBRA process can be referred to as Msg1, Msg2, Msg3, and Msg4. Msg1 can be a message including an RA preamble. Msg2 can be a RAR message. Msg3 and Msg4 can be messages sent and received for contention resolution. UL authorization for Msg3 can be transmitted via Msg2.

[0174] exist Figure 11 In an exemplary implementation, TRPx can send a PDCCH command to the terminal (S1101). In other words, the base station can send a PDCCH command to the terminal via TRPx. The terminal can receive the PDCCH command from TRPx (S1101). The terminal can perform the RA procedure initiated by the PDCCH command with TRPy (S1102, S1103, S1104, S1105). Step S1102 can be the process of sending and receiving Msg1 between the terminal and TRPy. In step S1102, the terminal can send Msg1 to TRPy, and TRPy can receive Msg1 from the terminal. Step S1103 can be the process of sending and receiving Msg2 between the terminal and TRPy. In step S1103, TRPy can send Msg2 to the terminal, and the terminal can receive Msg2 from TRPy. Step S1104 can be the process of sending and receiving Msg3 between the terminal and TRPy. In step S1104, the terminal can send Msg3 to TRPy, and TRPy can receive Msg3 from the terminal. Step S1105 can be the process of sending and receiving Msg4 between the terminal and TRPy. In step S1105, TRPy can send Msg4 to the terminal, and the terminal can receive Msg4 from TRPy.

[0175] exist Figure 12 In an exemplary implementation, TRPx can send a PDCCH command to the terminal (S1201). In other words, the base station can send a PDCCH command to the terminal via TRPx. The terminal can receive the PDCCH command from TRPx (S1201). The terminal can execute the RA procedure initiated by the PDCCH command (S1202, S1204, S1205, S1206). During the RA procedure, the transmission and reception of Msg1 can be performed between the terminal and TRPy, and the transmission and reception of Msg2, Msg3, and Msg4 can be performed between the terminal and TRPx. Step S1202 can be the transmission and reception of Msg1 between the terminal and TRPy. In step S1202, the terminal can send Msg1 to TRPy, and TRPy can receive Msg1 from the terminal.

[0176] The TRPy receiving Msg1 can generate the information required for generating Msg2 (e.g., a RAR message). The information required for generating Msg2 can be generated at a base station connected to the TRPy. The information required for generating the RAR message can include information about the TA measured by the TRPy. The TRPy can determine the TA based on Msg1 received from the terminal and can generate TA information including the determined TA. The information required for generating the RAR message can include the RNTI determined by the TRPy. The information required for generating the RAR message can be defined as RAR configuration information. In step S1203, the TRPy can send the RAR configuration information to the TRPx, and the TRPx can receive the RAR configuration information from the TRPy. Step S1203 can be a sharing step for RAR configuration information (e.g., TA information). The RAR configuration information can include at least one of TA information, information required for determining the TA, an RNTI for the transmission of Msg2, or information required for determining the RNTI for the transmission of Msg2. Step S1203 can be combined with... Figure 10 The steps S1003 shown are performed in the same or similar manner.

[0177] Step S1204 can be the process of sending and receiving Msg2 between the terminal and TRPx. In step S1204, TRPx can send Msg2 to the terminal, and the terminal can receive Msg2 from TRPx. Step S1205 can be the process of sending and receiving Msg3 between the terminal and TRPx. In step S1205, the terminal can send Msg3 to TRPx, and TRPx can receive Msg3 from the terminal. Step S1206 can be the process of sending and receiving Msg4 between the terminal and TRPx. In step S1206, TRPx can send Msg4 to the terminal, and the terminal can receive Msg4 from TRPx.

[0178] Besides the sending and receiving process of Msg4, Figure 13 Exemplary implementations can be compared with Figure 12 The exemplary implementation is performed in the same manner. Steps S1301, S1302, S1303, S1304, and S1305 can be performed in the same manner as steps S1201, S1202, S1203, S1204, and S1205, respectively. In step S1306, TRPy can send Msg4 to the terminal, and the terminal can receive Msg4 from TRPy.

[0179] Besides the sending and receiving processes of Msg3 and Msg4, Figure 14 Exemplary implementations can be compared with Figure 12The exemplary implementation is performed in the same manner. Steps S1401, S1402, S1403, and S1404 can be performed in the same manner as steps S1201, S1202, S1203, and S1204, respectively. In step S1405, the terminal can send Msg3 to TRPy, and TRPy can receive Msg3 from the terminal. In step S1406, TRPy can send Msg4 to the terminal, and the terminal can receive Msg4 from TRPy.

[0180] Besides the sending and receiving process of Msg3, Figure 15 Exemplary implementations can be compared with Figure 12 The exemplary implementation is performed in the same manner. Steps S1501, S1502, S1503, S1504, and S1506 can be performed in the same manner as steps S1201, S1202, S1203, S1204, and S1206, respectively. In step S1505, the terminal can send Msg3 to TRPy, and TRPy can receive Msg3 from the terminal.

[0181] The four-step CBRA process based on cross-PDCCH instructions can be based on Figures 11 to 15 One of the methods is used to execute this. The base station can configure (e.g., instruct) the terminal via signaling. Figures 11 to 15 One method is as follows. The terminal can perform a four-step CBRA procedure based on cross-PDCCH instructions, according to a method indicated by the base station. This can be fixed. Figures 11 to 15 One method, and can be based on a fixed approach to execute a four-step CBRA process based on PDCCH instructions. When configured (e.g., operating). Figures 11 to 15 One approach is to configure the execution method of the four-step CBRA procedure based on the PDCCH instruction as follows.

[0182] In a communication system where TRP#0 and TRP#1 exist, the TCI status information for TRP#0 can be associated with CORESET pool #0, and the TCI status information for TRP#1 can be associated with CORESET pool #1. The PDCCH (e.g., PDCCH instructions) of TRP#0 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #0), and the PDCCH (e.g., PDCCH instructions) of TRP#1 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #1).

[0183] Msg1 can be a signaling message sent to the TRP that is the measurement target of the TA. Since the DCI that schedules RAR messages during the RA process transmits via Type 1 CSS, RAR messages can be transmitted via the TRP associated with the CORESET pool to which the CORESET configured with Type 1 CSS belongs. When Type 1 CSS is configured in a CORESET associated with CORESET pool #0, RAR messages can be transmitted via TRP #0. When Type 1 CSS is configured in a CORESET associated with CORESET pool #1, RAR messages can be transmitted via TRP #1. For another example, when Type 1 CSS is configured in CORESETs associated with both CORESET pool #0 and CORESET pool #1, RAR messages can be transmitted via TRP #0 and / or TRP #1. Since the TRP capable of transmitting RAR messages can be determined based on the configuration of Type 1 CSS, the TRP in which the RAR message can be transmitted can be determined based on the configuration of Type 1 CSS. Figures 11 to 15 In an exemplary implementation, the TRP of Msg2 is transmitted.

[0184] A UL authorization for the transmission of Msg3 can be sent to the terminal via Msg2. In other words, Msg2 sent to the terminal may include a UL authorization for the transmission of Msg3. Msg2 may include a UL authorization, TCI status information, and / or a TAG ID. The TCI status information and / or TAG ID may be configured to be associated with the UL authorization. The UL authorization, TCI status information, and / or TAG ID included in Msg2 may be used to indicate the TRP that is the transmission target of Msg3. For example, the TCI status information and / or TAG ID may be associated with a TRP that is the transmission target of Msg3. The terminal may identify the TRP that is the transmission target of Msg3 based on the UL authorization, TCI status information, and / or TAG ID included in Msg2, and may send Msg3 to the identified TRP.

[0185] The DCI that schedules the transmission of Msg4 can be transmitted on the PDCCH, and Msg4 can be transmitted on the PDSCH indicated by the DCI. The base station can determine the TRP for transmitting Msg4, and the TRP determined by the base station can be used to send Msg4 to the terminal.

[0186] The TRP for sending and receiving each of Msg1, Msg2, Msg3, and Msg4 can be determined based on configuration information. This configuration information can be used to... Figures 11 to 15 One of the methods shown.

[0187] exist Figures 11 to 15In the method shown, a TRP capable of transmitting PDCCH instructions can be configured. In a communication system where TRP#0 and TRP#1 exist, the TCI status information for TRP#0 can be associated with CORESET pool #0, and the TCI status information for TRP#1 can be associated with CORESET pool #1. The PDCCH (e.g., PDCCH instructions) of TRP#0 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #0), and the PDCCH (e.g., PDCCH instructions) of TRP#1 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #1).

[0188] A core set for transmitting cross-PDCCH instructions can be configured to be associated with a specific core set pool index. For example, the transmission of cross-PDCCH instructions in a core set associated with core set pool #0 can be configured. Conversely, the transmission of cross-PDCCH instructions in a core set associated with core set pool #1 can be configured. In another example, the transmission of cross-PDCCH instructions in core sets associated with both core set pools #0 and #1 can be configured. The base station can configure core sets for transmitting cross-PDCCH instructions and can send information about the configuration to the terminal via signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal can expect to receive cross-PDCCH instructions in the core sets configured by the base station.

[0189] Apart from Figures 11 to 15 In addition to the method shown, a four-step CBRA procedure based on the PDCCH instruction can be performed as follows.

[0190] Figure 16 This is a sequence diagram illustrating the four-step CBRA process based on the PDCCH instruction.

[0191] like Figure 16 As shown, TRPx can send PDCCH commands to the terminal (S1601). In other words, the base station can send PDCCH commands to the terminal via TRPx. The terminal can receive PDCCH commands from TRPx (S1601). In step S1601, PDCCH commands can be transmitted to trigger the RA procedure for TRPx. In other words, in Figures 11 to 15 In an exemplary implementation, the PDCCH command for TRPx is transmitted to trigger the RA procedure for TRPy, but in Figure 16 In an exemplary implementation, a PDCCH instruction for TRPx can be transmitted to trigger the RA process for TRPx.

[0192] The terminal can execute the RA procedure initiated by the PDCCH instruction with TRPx (S1602, S1603, S1604, S1605). Step S1602 can be the process of sending and receiving Msg1 between the terminal and TRPx. In step S1602, the terminal can send Msg1 to TRPx, and TRPx can receive Msg1 from the terminal. Step S1603 can be the process of sending and receiving Msg2 between the terminal and TRPx. In step S1603, TRPx can send Msg2 to the terminal, and the terminal can receive Msg2 from TRPx. Step S1604 can be the process of sending and receiving Msg3 between the terminal and TRPx. In step S1604, the terminal can send Msg3 to TRPx, and TRPx can receive Msg3 from the terminal. Step S1605 can be the process of sending and receiving Msg4 between the terminal and TRPx. In step S1605, TRPx can send Msg4 to the terminal, and the terminal can receive Msg4 from TRPx.

[0193] Figure 16 The RA process in [the context] can be related to Figures 11 to 15 The RA process shown is performed in the same or similar manner. Figure 16 The RA process in the context can be for Figures 11 to 15 The RA process shown is a modified RA process or an extended RA process. Figure 16 The RA process in the middle can be based on Figures 11 to 15 The RA process shown is executed in combination.

[0194] The RA process can be either the same as the TRP that transmits the PDCCH command, or the RA process of another TRP that is different from the TRP that transmits the PDCCH command (e.g., across PDCCH commands). In this case, the PDCCH command may implicitly or explicitly include information indicating the TRP (which is the target of the RA process triggered by the PDCCH command). TCI status information for communicating with the TRP (e.g., the target of the TA process) may be included in the PDCCH command. The TRP that is the target of the RA process can be indicated by one of the indication methods #1 to #6 described above. The TRP that is the target of the RA process can be indicated by a modified or extended method of the indication methods #1 to #6 described above. The TRP that is the target of the RA process can be indicated by a combination of two or more of the indication methods #1 to #6 described above.

[0195] 2.2 Two-step CBRA process Figure 17 and Figure 18 This is a sequence diagram illustrating a two-step CBRA process based on the PDCCH instruction.

[0196] like Figure 17 and Figure 18 As shown, a two-step CBRA process can be triggered (e.g., initiated) by a cross-PDCCH instruction. The messages transmitted during a two-step CBRA process can be referred to as MsgA and MsgB. MsgA can be messages that include Msg1 and Msg3 in a four-step RA process. In other words, MsgA can include the RA preamble and PUSCH. MsgB can be messages that include Msg2 and Msg4 in a four-step RA process. The DCI scheduling the transmission of MsgB can be transmitted on the PDCCH, and MsgB can be transmitted on the PDSCH indicated by the DCI.

[0197] exist Figure 17 In an exemplary implementation, TRPx can send a PDCCH command to the terminal (S1701). In other words, the base station can send a PDCCH command to the terminal via TRPx. The terminal can receive the PDCCH command from TRPx (S1701). The terminal can perform an RA procedure initiated by the PDCCH command with TRPy (S1702, S1703). Step S1702 can be a process of sending and receiving MsgA between the terminal and TRPy. In step S1702, the terminal can send MsgA to TRPy, and TRPy can receive MsgA from the terminal. Step S1703 can be a process of sending and receiving MsgB between the terminal and TRPy. In step S1703, TRPy can send MsgB to the terminal, and the terminal can receive MsgB from TRPy.

[0198] exist Figure 18In an exemplary implementation, TRPx can send a PDCCH command to the terminal (S1801). In other words, the base station can send a PDCCH command to the terminal via TRPx. The terminal can receive the PDCCH command from TRPx (S1801). The terminal can execute the RA procedure initiated by the PDCCH command (S1802, S1804). During the RA procedure, the transmission and reception of MsgA can be performed between the terminal and TRPy, and the transmission and reception of MsgB can be performed between the terminal and TRPx. Step S1802 can be the transmission and reception of MsgA between the terminal and TRPy. In step S1802, the terminal can send MsgA to TRPy, and TRPy can receive MsgA from the terminal. TRPy, which receives MsgA, can generate the information required for the generation of MsgB. The information required for the generation of MsgB can include information about the TA measured by TRPy. TRPy can determine the TA based on the MsgA received from the terminal and can generate TA information including the determined TA. The TA can be determined in the base station connected to TRPy. The information required for MsgB generation may include the RNTI determined by TRPy. The RNTI can be determined in the base station connected to TRPy.

[0199] The information required for generating MsgB can be defined as RAR configuration information. In step S1803, TRPy can send RAR configuration information to TRPx, and TRPx can receive RAR configuration information from TRPy. Step S1803 can be a sharing step of RAR configuration information (e.g., TA information). RAR configuration information may include at least one of TA information, information required to determine the TA, RNTI for the transmission of MsgB, or information required to determine the RNTI for the transmission of MsgB. S1803 can be combined with... Figure 10 Step S1003 shown is performed in the same or similar manner. In step S1804, TRPx can send MsgB to the terminal, and the terminal can receive MsgB from TRPx.

[0200] A two-step CBRA process based on cross-PDCCH instructions can be based on Figure 17 and Figure 18 One of the methods is used to execute this. The base station can configure (e.g., instruct) the terminal via signaling. Figure 17 and Figure 18 One method is as follows. The terminal can perform a two-step CBRA procedure based on cross-PDCCH instructions instructed by the base station. This can be fixed. Figure 17 and Figure 18 One method, and can be used to perform a two-step CBRA procedure based on cross-PDCCH instructions using a fixed approach. When configured (e.g., operating). Figure 17 and Figure 18 One approach is to configure a two-step CBRA procedure based on cross-PDCCH instructions as follows.

[0201] In a communication system where TRP#0 and TRP#1 exist, the TCI status information for TRP#0 can be associated with CORESET pool #0, and the TCI status information for TRP#1 can be associated with CORESET pool #1. The PDCCH (e.g., PDCCH instructions) of TRP#0 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #0), and the PDCCH (e.g., PDCCH instructions) of TRP#1 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #1).

[0202] MsgA can be a signaling message sent to the TRP that is the measurement target of the TA. Since the DCI scheduling MsgB during the RA process is transmitted via Type 1 CSS, MsgB can be transmitted via the TRP associated with the CORESET pool to which the CORESET configured with Type 1 CSS belongs. When Type 1 CSS is configured in a CORESET associated with CORESET pool #0, MsgB can be transmitted via TRP #0. Conversely, when Type 1 CSS is configured in a CORESET associated with CORESET pool #1, MsgB can be transmitted via TRP #1. In another example, when Type 1 CSS is configured in CORESETs associated with both CORESET pool #0 and CORESET pool #1, MsgB can be transmitted via TRP #0 and / or TRP #1. Since the TRP capable of transmitting MsgB can be determined based on the configuration of Type 1 CSS, the TRP for transmitting MsgB can be determined based on the configuration of Type 1 CSS. Figure 17 and Figure 18 In an exemplary implementation, the TRP for transmitting MsgB is shown.

[0203] exist Figure 17 and Figure 18In the method shown, a TRP capable of transmitting PDCCH instructions can be configured. In a communication system where TRP#0 and TRP#1 exist, the TCI status information for TRP#0 can be associated with CORESET pool #0, and the TCI status information for TRP#1 can be associated with CORESET pool #1. The PDCCH (e.g., PDCCH instructions) of TRP#0 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #0), and the PDCCH (e.g., PDCCH instructions) of TRP#1 can be transmitted through a CORESET associated with (e.g., belonging to CORESET pool #1).

[0204] A core set for transmitting cross-PDCCH instructions can be configured to be associated with a specific core set pool index. For example, the transmission of cross-PDCCH instructions in a core set associated with core set pool #0 can be configured. Conversely, the transmission of cross-PDCCH instructions in a core set associated with core set pool #1 can be configured. In another example, the transmission of cross-PDCCH instructions in core sets associated with both core set pools #0 and #1 can be configured. The base station can configure core sets for transmitting cross-PDCCH instructions and can send information about the configuration to the terminal via signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal can expect to receive cross-PDCCH instructions in the core sets configured by the base station.

[0205] Apart from Figure 17 and Figure 18 In addition to the method shown, a two-step CBRA procedure based on the PDCCH instruction can be performed as follows.

[0206] Figure 19 This is a sequence diagram illustrating a two-step CBRA process based on the PDCCH instruction.

[0207] like Figure 19 As shown, TRPx can send PDCCH commands to the terminal (S1901). In other words, the base station can send PDCCH commands to the terminal via TRPx. The terminal can receive PDCCH commands from TRPx (S1901). In step S1901, PDCCH commands can be transmitted to trigger the RA procedure for TRPx. In other words, in Figure 17 and Figure 18 In an exemplary implementation, the PDCCH command for TRPx is transmitted to trigger the RA procedure for TRPy, but in Figure 19In an exemplary implementation, a PDCCH instruction for TRPx can be transmitted to trigger the RA process for TRPx.

[0208] The terminal can execute the RA procedure initiated by the PDCCH instruction with TRPx (S1902, S1903). Step S1902 can be the process of sending and receiving MsgA between the terminal and TRPx. In step S1902, the terminal can send MsgA to TRPx, and TRPx can receive MsgA from the terminal. Step S1903 can be the process of sending and receiving MsgB between the terminal and TRPx. In step S1903, TRPx can send MsgB to the terminal, and the terminal can receive MsgB from TRPx.

[0209] Figure 19 The RA process in [the context] can be related to Figure 17 and Figure 18 The RA process shown is performed in the same or similar manner. Figure 19 The RA process in the context can be for Figure 17 and Figure 18 The RA process shown is a modified RA process or an extended RA process. Figure 19 The RA process in the middle can be based on Figure 17 and Figure 18 The RA process shown is executed in combination.

[0210] The RA process can be either the same as the TRP that transmits the PDCCH command, or the RA process of another TRP that is different from the TRP that transmits the PDCCH command (e.g., across PDCCH commands). In this case, the PDCCH command may implicitly or explicitly include information indicating the TRP (which is the target of the RA process triggered by the PDCCH command). TCI status information for communicating with the TRP (e.g., the target of the TA process) may be included in the PDCCH command. The TRP that is the target of the RA process can be indicated by one of the indication methods #1 to #6 described above. The TRP that is the target of the RA process can be indicated by a modified or extended method of the indication methods #1 to #6 described above. The TRP that is the target of the RA process can be indicated by a combination of two or more of the indication methods #1 to #6 described above.

[0211] The operation of the method according to an exemplary embodiment of the present invention can be implemented as a computer-readable program or code in a computer-readable recording medium. The computer-readable recording medium may include all types of recording means storing data readable by a computer system. Furthermore, the computer-readable recording medium may store and execute programs or code that may be distributed across computer systems connected via a network and read in a distributed manner by a computer.

[0212] Computer-readable recording media may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, or flash memory. Program instructions may include not only machine language code created by a compiler, but also high-level language code that can be executed by a computer using an interpreter.

[0213] Although some aspects of the invention have been described in the context of the apparatus, these aspects may refer to the corresponding description according to the method, and blocks or devices may correspond to steps or features of the method. Similarly, aspects described in the context of the method may be represented as features of corresponding blocks or items or corresponding devices. Some or all steps of the method may be performed by (or using) hardware devices such as microprocessors, programmable computers, or electronic circuits. In some embodiments, one or more of the most important steps of the method may be performed by such devices.

[0214] In some exemplary embodiments, programmable logic devices, such as field-programmable gate arrays (FPGAs), can be used to perform some or all of the functions of the methods described herein. In some exemplary embodiments, FPGAs can be operated with a microprocessor to perform one of the methods described herein. Typically, the methods are preferably performed by specific hardware means.

[0215] The description of this invention is merely exemplary in nature, and therefore variations thereof without departing from the spirit of the invention are intended to be within its scope. Such variations should not be considered as departing from the spirit and scope of the invention. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope defined by the appended claims.

Claims

1. A method of a user equipment (UE), comprising: receiving a cross-physical downlink control channel (PDCCH) instruction from a first transmission and reception point (TRP); identifying a second TRP as a target of a random access (RA) procedure based on first indication information included in the cross-PDCCH instruction; and transmitting a message including a RA preamble to the second TRP, wherein the first TRP and the second TRP are different TRPs.

2. The method of claim 1, wherein, The first indication information indicates a timing advance group (TAG) identifier (ID), and the TAG ID is configured to be associated with a transmission configuration indicator (TCI) state.

3. The method of claim 1, wherein, The first indication information indicates a TCI state for the second TRP.

4. The method of claim 1, wherein, The first indication information indicates a dedicated preamble for the RA procedure, a dedicated preamble group to which the dedicated preamble belongs is configured to be associated with a control resource set (CORESET) pool, and the CORESET pool is configured to be associated with a TCI state.

5. The method of claim 1, wherein, The first indication information indicates a random access channel (RACH) occasion (RO) for transmitting the message, a RO group to which the RO belongs is configured to be associated with a CORESET pool, and the CORESET pool is configured to be associated with a TCI state.

6. The method of claim 1, wherein, The first indication information indicates a cell identifier (ID), and the second TRP belongs to a cell indicated by the cell ID.

7. The method of claim 1, wherein, The message including the RA preamble is a Msg1 in a four-step RA procedure or a MsgA in a two-step RA procedure.

8. The method of claim 1, further comprising receiving, from the first TRP or the second TRP, a random access response (RAR) message as a response to the message, wherein, The RAR message includes timing advance (TA) information for the second TRP.

9. The method of claim 8, wherein, The UE expects to receive the RAR message from one of the first TRP or the second TRP associated with a CORESET pool to which a CORESET configured with a type 1 common search space (CSS) belongs.

10. The method of claim 8, wherein, The RAR message further includes an uplink (UL) grant and second indication information indicating a transmission target of a Msg3, and the Msg3 is transmitted to one of the first TRP or the second TRP determined based on the second indication information. 11.A method of a base station, comprising: generating a cross-physical downlink control channel (PDCCH) instruction indicating a second transmission and reception point (TRP) as a target of a random access (RA) procedure; and transmitting the cross-PDCCH instruction to a user equipment (UE) via a first TRP, wherein in the RA procedure triggered by the cross-PDCCH instruction, a message including a RA preamble is transmitted from the UE to the second TRP, and the first TRP and the second TRP are different TRPs connected to the base station.

12. The method of claim 11, wherein, The first indication information indicates a timing advance group (TAG) identifier (ID), and the TAG ID is configured to be associated with a transmission configuration indicator (TCI) state.

13. The method of claim 11, wherein, The first indication information indicates a TCI state for the second TRP.

14. The method of claim 11, wherein, The first indication information indicates a dedicated preamble for the RA procedure, a dedicated preamble group to which the dedicated preamble belongs is configured to be associated with a control resource set (CORESET) pool, and the CORESET pool is configured to be associated with a TCI state.

15. The method of claim 11, wherein, The first indication information indicates a random access channel (RACH) occasion (RO) for transmission of the message, the RO belongs to a RO group configured to be associated with a CORESET pool, and the CORESET pool is configured to be associated with a TCI state.

16. The method of claim 11, wherein, The first indication information indicates a cell identifier (ID), and the second TRP belongs to a cell indicated by the cell ID.

17. The method of claim 11, wherein, The message including the RA preamble is a Msg1 in a four-step RA procedure or a MsgA in a two-step RA procedure.

18. A user equipment (UE) comprising at least one processor, wherein, The at least one processor causes the UE to perform: receiving, from a first transmission and reception point (TRP), a cross-physical downlink control channel (PDCCH) instruction; identifying, based on first indication information included in the cross-PDCCH instruction, a second TRP that is a target of a random access (RA) procedure; and transmitting, to the second TRP, a message including an RA preamble, wherein the first TRP and the second TRP are different TRPs.

19. The UE of claim 18, wherein, The first indication information indicates at least one of: a timing advance group (TAG) identifier (ID) for the second TRP, a transmission configuration indicator (TCI) state for the second TRP, a dedicated preamble for the RA procedure, a random access channel (RACH) occasion (RO) for transmission of the message, or a cell identifier (ID) indicating a cell to which the second TRP belongs.

20. The UE of claim 18, wherein, The at least one processor further causes the UE to perform: receiving, from the first TRP or the second TRP, a random access response (RAR) message that is a response to the message, wherein the RAR message is received from one of the first TRP or the second TRP that is associated with a control resource set (CORESET) pool to which a CORESET configured with a type 1 common search space (CSS) belongs.

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