Method and device for cross-TRP random access

Abstract

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

Description

Method and device for cross-TRP random access

[0001] The present disclosure relates to random access techniques, and more particularly to techniques for cross-TRP random access in a communication system including one or more transmission and reception points (TRPs).

[0002] Communication networks (e.g., 5G communication networks, 6G communication networks, etc.) are being developed to provide improved communication services compared to existing communication networks (e.g., long term evolution (LTE), advanced LTE-A (LTE-A), etc.). 5G communication networks (e.g., new radio (NR) communication networks) can support frequency bands above 6 GHz as well as frequency bands below 6 GHz. That is, 5G communication networks can support FR1 bands and / or FR2 bands. 5G communication networks can support various communication services and scenarios compared to LTE communication networks. For example, usage scenarios of 5G communication networks can include enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communication (URLLC), massive Machine Type Communication (mMTC), etc.

[0003] Compared to 5G, 6G communication networks can support a wider range of communication services and scenarios. 6G communication networks can meet requirements for ultra-high performance, ultra-high bandwidth, ultra-high space, ultra-high precision, ultra-intelligence, and / or ultra-reliability. 6G communication networks can support diverse and wide frequency bands and be applied to various usage scenarios (e.g., terrestrial communications, non-terrestrial communications, sidelink communications, etc.).

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

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

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

[0007] In mTRP-based communication, the first TRP can transmit a physical downlink control channel (PDCCH) order to the terminal. The terminal can receive the PDCCH order from the first TRP and initiate an RA procedure based on the PDCCH order. In this case, the terminal may need to transmit the RA preamble to a different TRP instead of the first TRP. Specific methods for supporting this operation may be required.

[0008] An object of the present disclosure to solve the above problems is to provide a method and device for cross-TRP random access in a communication system including one or more TRPs (transmission and reception points).

[0009] A method of a UE according to embodiments of the present disclosure for achieving the above object includes the steps of receiving a cross-PDCCH order from a first TRP, identifying a second TRP that is a target of performing an RA procedure based on first indication information included in the cross-PDCCH order, and transmitting a message including an RA preamble to the second TRP, wherein the first TRP and the second TRP are different TRPs.

[0010] The above first instruction information may indicate a TAG ID, and the TAG ID may be set to be associated with a TCI state.

[0011] The above first instruction information may indicate a TCI status for the second TRP.

[0012] The above first instruction information may indicate a dedicated preamble for the RA procedure, a dedicated preamble group to which the dedicated preamble belongs may be set to be associated with a CORESET pool, and the CORESET pool may be set to be associated with a TCI state.

[0013] The above first instruction information may indicate an RO for transmission of the message, an RO group to which the RO belongs may be set to be associated with a CORESET pool, and the CORESET pool may be set to be associated with a TCI state.

[0014] The above first instruction information may indicate a cell ID, and the second TRP may belong to a cell indicated by the cell ID.

[0015] The message including the above RA preamble may be Msg1 in a 4-step RA procedure or MsgA in a 2-step RA procedure.

[0016] The method of the UE may further include the step of receiving a RAR message in response to the message from the first TRP or the second TRP, wherein the RAR message may include TA information for the second TRP.

[0017] The UE may expect to receive the RAR message from one TRP associated with a CORESET pool to which a CORESET with Type 1 CSS set belongs, either from the first TRP or the second TRP.

[0018] The RAR message may further include second indication information indicating a transmission target of the UL grant and Msg3, and the Msg3 may be transmitted to one of the first TRP or the second TRP, which is determined based on the second indication information.

[0019] A method of a base station according to embodiments of the present disclosure for achieving the above object includes the steps of generating a cross-PDCCH order indicating a second TRP that is a target of performing an RA procedure, and transmitting the cross-PDCCH order to a UE through a first TRP, wherein a message including an RA preamble in the RA procedure triggered by the cross-PDCCH order 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.

[0020] The above first instruction information may indicate a TAG ID, and the TAG ID may be set to be associated with a TCI state.

[0021] The above first instruction information may indicate a TCI status for the second TRP.

[0022] The above first instruction information may indicate a dedicated preamble for the RA procedure, a dedicated preamble group to which the dedicated preamble belongs may be set to be associated with a CORESET pool, and the CORESET pool may be set to be associated with a TCI state.

[0023] The above first instruction information may indicate an RO for transmission of the message, an RO group to which the RO belongs may be set to be associated with a CORESET pool, and the CORESET pool may be set to be associated with a TCI state.

[0024] The above first instruction information may indicate a cell ID, and the second TRP may belong to a cell indicated by the cell ID.

[0025] The message including the above RA preamble may be Msg1 in a 4-step RA procedure or MsgA in a 2-step RA procedure.

[0026] According to embodiments of the present disclosure for achieving the above object, a UE includes at least one processor, wherein the at least one processor causes the UE to receive a cross-PDCC order from a first TRP, identify a second TRP that is a target of performing an RA procedure based on first indication information included in the cross-PDCCH order, and transmit 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 a TAG ID for the second TRP, a TCI state for the second TRP, a dedicated preamble for the RA procedure, an RO for transmission of the message, or a cell ID indicating a cell to which the second TRP belongs.

[0028] The at least one processor may further cause the UE to receive a RAR message in response to the message from the first TRP or the second TRP, wherein the RAR message may be received from one of the first TRP or the second TRP associated with a CORESET pool to which a CORESET with type 1 CSS set belongs.

[0029] According to the present disclosure, a terminal can receive a cross-PDCCH (physical downlink control channel) order from a first transmission and reception point (TRP), identify a second TRP that is a target of an RA (random access) procedure based on information included in the cross-PDCCH order, and transmit a message including an RA preamble to the second TRP. Since the second TRP that is a target of the RA procedure can be identified based on information included in the cross-PDCCH order, an RA procedure based on the cross-PDCCH order can be efficiently performed.

[0030] Figure 1 is a conceptual diagram illustrating embodiments of a communication system.

[0031] Figure 2 is a block diagram illustrating embodiments of communication nodes constituting a communication system.

[0032] Figure 3 is a block diagram illustrating embodiments of communication nodes that perform communication.

[0033] Figure 4a is a block diagram illustrating embodiments of a transmission path.

[0034] Figure 4b is a block diagram illustrating embodiments of a receiving path.

[0035] Figure 5 is a conceptual diagram illustrating embodiments of system frames in a communication system.

[0036] Figure 6 is a conceptual diagram illustrating embodiments of subframes in a communication system.

[0037] Figure 7 is a conceptual diagram illustrating embodiments of slots in a communication system.

[0038] Figure 8 is a conceptual diagram illustrating embodiments of time-frequency resources in a communication system.

[0039] Figure 9 is a flowchart illustrating a CFRA procedure based on cross-PDCCH order.

[0040] Figure 10 is a flowchart illustrating a CFRA procedure based on cross-PDCCH order.

[0041] Figures 11 to 15 are flowcharts illustrating a four-step CBRA procedure based on cross-PDCCH order.

[0042] Figure 16 is a flowchart illustrating a 4-step CBRA procedure based on PDCCH order.

[0043] Figures 17 and 18 are flowcharts illustrating a two-step CBRA procedure based on cross-PDCCH order.

[0044] Figure 19 is a flowchart illustrating a two-step CBRA procedure based on PDCCH order.

[0045] This disclosure may be subject to various modifications and various embodiments. Specific embodiments are illustrated and described in detail in the drawings. However, this is not intended to limit the disclosure to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the disclosure.

[0046] While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present disclosure, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component." The term "and / or" may refer to a combination of multiple related items described herein or to any of multiple related items described herein.

[0047] In the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.” Additionally, in the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.”

[0048] In the present disclosure, (re)transmission may mean “transmission,” “retransmission,” or “transmission and retransmission,” (re)setting may mean “setting,” “resetting,” or “setting and resetting,” (re)connection may mean “connection,” “reconnection,” or “connection and reconnection,” and (re)connection may mean “connection,” “reconnection,” or “connection and reconnection.”

[0049] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0050] The terminology used in this disclosure is only used to describe specific embodiments and is not intended to limit the present disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this disclosure, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0051] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0052] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. In order to facilitate an overall understanding in describing the present disclosure, the same reference numerals will be used for identical components in the drawings, and redundant descriptions of identical components will be omitted. In addition to the embodiments explicitly described in the present disclosure, operations may be performed according to combinations of embodiments, extensions of embodiments, and / or modifications of embodiments. The performance of some operations may be omitted, and the order of operation may be changed.

[0053] In an embodiment, even if a method (e.g., transmitting or receiving a signal) performed by a first communication node among communication nodes is described, a corresponding second communication node can perform a method (e.g., receiving or transmitting a signal) corresponding to the method performed by the first communication node. That is, if an operation of a UE (user equipment) is described, a corresponding base station can perform an operation corresponding to the operation of the UE. Conversely, if an operation of a base station is described, a corresponding UE can perform an operation corresponding to the operation of the base station.

[0054] A base station may be referred to as a NodeB, an evolved NodeB, a gNodeB (next generation node B), a gNB, a device, an apparatus, a node, a communication node, a BTS (base transceiver station), a RRH (radio remote head), a TRP (transmission reception point), a RU (radio unit), an RSU (road side unit), a radio transceiver, an access point, an access node, etc. A UE may be referred to as a terminal, a device, an apparatus, a node, a communication node, an end node, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, an OBU (on-broad unit), etc.

[0055] In the present disclosure, signaling may be at least one of upper layer signaling, MAC signaling, or PHY (physical) signaling. A message used for upper layer signaling may be referred to as an "upper layer message" or an "upper layer signaling message." A message used for MAC signaling may be referred to as a "MAC message" or a "MAC signaling message." A message used for PHY signaling may be referred to as a "PHY message" or a "PHY signaling message." Upper layer signaling may refer to a transmission and reception operation of system information (e.g., a master information block (MIB), a system information block (SIB)) and / or a radio resource control (RRC) message. MAC signaling may refer to a transmission and reception operation of a MAC control element (CE). PHY signaling may refer to a transmission and reception operation of control information (e.g., downlink control information (DCI), uplink control information (UCI), sidelink control information (SCI)).

[0056] In the present disclosure, “an operation (e.g., a transmission operation) is set” may mean that “setting information for the operation (e.g., an information element, a parameter)” and / or “information instructing the performance of the operation” is signaled. “An information element (e.g., a parameter) is set” may mean that the information element is signaled. In the present disclosure, “a signal and / or a channel” may mean a signal, a channel, or “a signal and a channel,” and a signal may be used to mean “a signal and / or a channel.”

[0057] The communication network to which the embodiment is applied is not limited to what is described below, and the embodiment may be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, the communication network may be used in the same sense as the communication system.

[0058] Figure 1 is a conceptual diagram illustrating embodiments of a communication system.

[0059] Referring to FIG. 1, the communication system (100) may include a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). In addition, 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), a mobility management entity (MME)). If the communication system (100) is a 5G communication system (e.g., a new radio (NR) system), the core network may include an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), etc.

[0060] A plurality of communication nodes (110 to 130) can support a communication protocol (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.) specified in the 3GPP (3rd generation partnership project) standard. The plurality of communication nodes (110 to 130) may support CDMA (code division multiple access) technology, WCDMA (wideband CDMA) technology, TDMA (time division multiple access) technology, FDMA (frequency division multiple access) technology, OFDM (orthogonal frequency division multiplexing) technology, Filtered OFDM technology, CP (cyclic prefix)-OFDM technology, DFT-s-OFDM (discrete Fourier transform-spread-OFDM) technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier)-FDMA technology, NOMA (non-orthogonal multiple access) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, SDMA (space division multiple access) technology, etc. Each of the plurality of communication nodes may have the following structure.

[0061] Figure 2 is a block diagram illustrating embodiments of communication nodes constituting a communication system.

[0062] Referring to FIG. 2, a communication node (200) may include at least one processor (210), a memory (220), and a transmission / reception device (230) that is connected to a network and performs communication. In addition, the communication node (200) may further include an input interface device (240), an output interface device (250), a storage device (260), etc. Each component included in the communication node (200) may be connected by a bus (270) and communicate with each other.

[0063] The processor (210) can execute program commands stored in at least one of the memory (220) and the storage device (260). The processor (210) may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor in which the methods according to embodiments of the present disclosure are performed. Each of the memory (220) and the storage device (260) may be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (220) may be configured with at least one of a read-only memory (ROM) and a random access memory (RAM).

[0064] Referring again to FIG. 1, the communication system (100) may include a plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) and a plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) may form a macro cell. Each of the fourth base station (120-1) and the fifth base station (120-2) may form a small cell. The fourth base station (120-1), the third terminal (130-3), and the fourth terminal (130-4) may be within the cell coverage of the first base station (110-1). The second terminal (130-2), the fourth terminal (130-4), and the fifth terminal (130-5) may be within the cell coverage of the second base station (110-2). The fifth base station (120-2), the fourth terminal (130-4), the fifth terminal (130-5), and the sixth terminal (130-6) may be within the cell coverage of the third base station (110-3). The first terminal (130-1) may be within the cell coverage of the fourth base station (120-1). The sixth terminal (130-6) may be within the cell coverage of the fifth base station (120-2).

[0065] Here, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be referred to as a NodeB (NB), an evolved NodeB (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 NodeB (HNB), a home eNodeB (HeNB), a road side unit (RSU), a radio remote head (RRH), a transmission point (TP), a transmission and reception point (TRP), etc.

[0066] Each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as a 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] Meanwhile, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may operate in a different frequency band or may operate in the same frequency band. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to each other via an ideal backhaul link or a non-ideal backhaul link, and may exchange information with each other via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to the core network via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit a signal received from the core network to the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6), and can transmit a signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) to the core network.

[0068] Additionally, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may support MIMO transmission (e.g., single user (SU)-MIMO, multi user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, sidelink communication (e.g., device to device communication (D2D), proximity services (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) can perform an operation corresponding to the base station (110-1, 110-2, 110-3, 120-1, 120-2) and an operation supported by the base station (110-1, 110-2, 110-3, 120-1, 120-2). For example, the second base station (110-2) can transmit a signal to the fourth terminal (130-4) based on the SU-MIMO scheme, and the fourth terminal (130-4) can receive a signal from the second base station (110-2) by the SU-MIMO scheme. Alternatively, the second base station (110-2) can transmit signals to the fourth terminal (130-4) and the fifth terminal (130-5) based on the MU-MIMO method, and each of the fourth terminal (130-4) and the fifth terminal (130-5) can receive signals from the second base station (110-2) based on the MU-MIMO method.

[0069] Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can transmit a signal to the fourth terminal (130-4) based on the CoMP scheme, and the fourth terminal (130-4) can receive a signal from the first base station (110-1), the second base station (110-2), and the third base station (110-3) based on the CoMP scheme. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit and receive a signal with terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) within its cell coverage based on the CA scheme. Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can control sidelink communication between the fourth terminal (130-4) and the fifth terminal (130-5), and each of 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] Meanwhile, communication nodes performing communication in a communication network may be configured as follows. The communication node illustrated in Fig. 3 may be a specific embodiment of the communication node illustrated in Fig. 2.

[0071] Figure 3 is a block diagram illustrating embodiments of communication nodes that perform communication.

[0072] Referring to FIG. 3, each of the first communication node (300a) and the second communication node (300b) may be a base station or a UE. The first communication node (300a) may transmit a signal to the second communication node (300b). The transmission processor (311) included in the first communication node (300a) may receive data (e.g., a data unit) from a data source (310). The transmission processor (311) may 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 transmitting processor (311) may perform a processing operation on data (e.g., an encoding operation, a symbol mapping operation, etc.) to generate data symbol(s). The transmitting processor (311) may perform a processing operation on control information (e.g., an encoding operation, a symbol mapping operation, etc.) to generate control symbol(s). In addition, the transmitting processor (311) may generate synchronization / reference symbol(s) for a synchronization signal and / or a reference signal.

[0074] The Tx MIMO processor (312) may perform a spatial processing operation (e.g., a precoding operation) on data symbol(s), control symbol(s), and / or synchronization / reference symbol(s). The output (e.g., a symbol stream) of the Tx MIMO processor (312) may be provided to modulators (MODs) included in the transceivers (313a to 313t). The modulators (MODs) may perform a processing operation on the symbol stream to generate modulation symbols, and may perform an additional processing operation (e.g., an analog conversion operation, an amplification operation, a filtering operation, an upconversion operation) on the modulation symbols to generate signals. The signals generated by the modulators (MODs) of the transceivers (313a to 313t) may be transmitted via the antennas (314a to 314t).

[0075] Signals transmitted by the first communication node (300a) may be received by antennas (364a to 364r) of the second communication node (300b). Signals received by the antennas (364a to 364r) may be provided to demodulators (DEMODs) included in transceivers (363a to 363r). The demodulator (DEMOD) may perform a processing operation (e.g., a filtering operation, an amplification operation, a downconversion operation, a digital conversion operation) on the signal to obtain samples. The demodulator (DEMOD) may perform an additional processing operation on the samples to obtain symbols. The MIMO detector (362) may perform a MIMO detection operation on the symbols. The receiving processor (361) may perform a processing operation (e.g., a deinterleaving operation, a decoding operation) on the symbols. The output of the receiving processor (361) may be provided to a data sink (360) and a controller (366). For example, data may be provided to the data sink (360), and control information may be provided to the controller (366).

[0076] Meanwhile, the second communication node (300b) can transmit a signal 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 a data source (367) and perform a processing operation on the data to generate data symbol(s). The transmitting processor (368) can receive control information from the controller (366) and perform a processing operation on the control information to generate control symbol(s). In addition, the transmitting processor (368) can perform a processing operation on a reference signal to generate reference symbol(s).

[0077] The Tx MIMO processor (369) may perform spatial processing operations (e.g., precoding operations) on data symbol(s), control symbol(s), and / or reference symbol(s). The output (e.g., symbol stream) of the Tx MIMO processor (369) may be provided to modulators (MODs) included in the transceivers (363a to 363t). The modulators (MODs) may perform processing operations on the symbol streams to generate modulation symbols, and may perform additional processing operations (e.g., analog conversion operations, amplification operations, filtering operations, upconversion operations) on the modulation symbols to generate signals. The signals generated by the modulators (MODs) of the transceivers (363a to 363t) may be transmitted via the antennas (364a to 364t).

[0078] Signals transmitted by the second communication node (300b) may be received by the antennas (314a to 314r) of the first communication node (300a). The signals received by the antennas (314a to 314r) may be provided to demodulators (DEMODs) included in the transceivers (313a to 313r). The demodulator (DEMOD) may perform a processing operation (e.g., a filtering operation, an amplification operation, a downconversion operation, a digital conversion operation) on the signal to obtain samples. The demodulator (DEMOD) may perform an additional processing operation on the samples to obtain symbols. The MIMO detector (320) may perform a MIMO detection operation on the symbols. The receiving processor (319) may perform a processing operation (e.g., a deinterleaving operation, a decoding operation) on the symbols. The output of the receiving processor (319) may be provided to a data sink (318) and a controller (316). For example, data may be provided to the data sink (318) and control information may be provided to the controller (316).

[0079] Memories (315 and 365) can store data, control information, and / or program code. Scheduler (317) can perform scheduling operations for communication. The processors (311, 312, 319, 361, 368, 369) and controllers (316, 366) illustrated in FIG. 3 may be the processor (210) illustrated in FIG. 2 and may be used to perform the methods described in the present disclosure.

[0080] FIG. 4a is a block diagram illustrating embodiments of a transmission path, and FIG. 4b is a block diagram illustrating embodiments of a reception path.

[0081] Referring to FIGS. 4A and 4B, a transmission path (410) may be implemented in a communication node that transmits a signal, and a reception path (420) may be implemented in a communication node that receives a signal. The transmission path (410) may include a channel coding and modulation block (411), an S-to-P (serial-to-parallel) block (512), an N IFFT (Inverse Fast Fourier Transform) block (413), a P-to-S (parallel-to-serial) block (414), a CP (cyclic prefix) addition block (415), and an UC (up-converter) (UC) (416). The receiving path (420) may include a DC (down-converter) (421), a CP removal block (422), an S-to-P block (423), an N FFT block (424), a P-to-S block (425), and a channel decoding and demodulation block (426). Here, N may be a natural number.

[0082] In the transmission path (410), information bits may be input to a channel coding and modulation block (411). The channel coding and modulation block (411) may perform a coding operation (e.g., a low-density parity check (LDPC) coding operation, a polar coding operation, etc.) and a modulation operation (e.g., a quadrature phase shift keying (QPSK), a quadrature amplitude modulation (QAM), etc.) on the information bits. The output of the channel coding and modulation block (411) may be a sequence of modulation symbols.

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

[0084] The CP addition block (415) can insert a CP into a signal. The UC (416) can up-convert the frequency of the output of the CP addition block (415) to an RF (radio frequency) frequency. Additionally, the output of the CP addition block (415) can be filtered at the baseband before up-conversion.

[0085] A signal transmitted from a transmission path (410) may be input to a reception path (420). An operation in the reception path (420) may be the reverse operation of the operation in the transmission path (410). A DC (421) may down-convert the frequency of the received signal to a baseband frequency. A CP removal block (422) may remove a CP from a signal. The output of the CP removal block (422) may be a serial signal. An S-to-P block (423) may convert the serial signal into parallel signals. An N FFT block (424) may perform an FFT algorithm to generate N parallel signals. A P-to-S block (425) may convert the parallel signals into a sequence of modulation symbols. A channel decoding and demodulation block (426) may perform a demodulation operation on the modulation symbols and perform a decoding operation on the result of the demodulation operation to restore data.

[0086] In FIGS. 4A and 4B , Discrete Fourier Transform (DFT) and Inverse DFT (IDFT) may be used instead of FFT and IFFT. Each of the blocks (e.g., components) in FIGS. 4A and 4B may be implemented by at least one of hardware, software, or firmware. For example, some of the blocks in FIGS. 4A and 4B may be implemented by software, and the remaining blocks may be implemented by hardware or a “combination of hardware and software.” In FIGS. 4A and 4B , a block may be subdivided into multiple blocks, multiple blocks may be integrated into a single block, some blocks may be omitted, and blocks supporting other functions may be added.

[0087] Figure 5 is a conceptual diagram illustrating embodiments of a system frame in a communication system.

[0088] Referring to FIG. 5, time resources in a communication system can be divided into frame units. For example, system frames can be set consecutively in the time domain of the communication system. The length of a system frame can be 10 ms (milliseconds). The system frame number (SFN) can be set 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 the system frame after system frame #1023 can be #0.

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

[0090] Figure 6 is a conceptual diagram illustrating embodiments of subframes in a communication system.

[0091] Referring to FIG. 6, one subframe may include n slots, where n may be a natural number. Accordingly, one subframe may be composed of one or more slots.

[0092] Figure 7 is a conceptual diagram illustrating embodiments of slots in a communication system.

[0093] Referring to FIG. 7, a single slot may include one or more symbols. A single slot illustrated in FIG. 7 may include 14 symbols. The length of a slot may vary depending on the number and length of symbols contained in the slot. Alternatively, the length of a slot may vary depending on numerology.

[0094] In a communication system, the numerology applied to physical signals and channels may be variable. The numerology may be variable to meet various technical requirements of the communication system. In a communication system applying CP (cyclic prefix)-based OFDM waveform technology, the numerology may include subcarrier spacing and CP length (or CP type). Table 1 may be a first embodiment of a method for configuring a numerology for a CP-OFDM-based communication system. At least some of the numerologies in Table 1 may be supported depending on the frequency band in which the communication system operates. In addition, the communication system may additionally support numerologies not listed in Table 1.

[0095]

[0096] When the subcarrier spacing is 15 kHz (e.g., μ=0), the slot length can be 1 ms. In this case, one system frame can contain 10 slots. When the subcarrier spacing is 30 kHz (e.g., μ=1), the slot length can be 0.5 ms. In this case, one system frame can contain 20 slots.

[0097] When the subcarrier spacing is 60 kHz (e.g., μ=2), the slot length can be 0.25 ms. In this case, one system frame can contain 40 slots. When the subcarrier spacing is 120 kHz (e.g., μ=3), the slot length can be 0.125 ms. In this case, one system frame can contain 80 slots. When the subcarrier spacing is 240 kHz (e.g., μ=4), the slot length can be 0.0625 ms. In this case, one system frame can contain 160 slots.

[0098] A symbol may be configured as a downlink (DL) symbol, a flexible (FL) symbol, or an uplink (UL) symbol. A slot consisting solely of DL symbols may be referred to as a "DL slot," a slot consisting solely of FL symbols may be referred to as an "FL slot," and a slot consisting solely of UL symbols may be referred to as a "UL slot."

[0099] The slot format can be semi-statically configured by 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 cell-specifically. In addition, the semi-static slot format can be additionally configured for each terminal through terminal-specific higher layer signaling (e.g., RRC signaling). The flexible symbol of the cell-specifically configured slot format can be overridden to a downlink symbol or an uplink symbol by terminal-specific higher layer signaling. In addition, the slot format can be dynamically indicated by physical layer signaling (e.g., a slot format indicator (SFI) included in DCI). The semi-statically configured slot format can be overridden by a dynamically indicated slot format. For example, the semi-statically configured flexible symbol can be overridden to a downlink symbol or an uplink symbol by the SFI.

[0100] The reference signal may be a channel state information-reference signal (CSI-RS), a sounding reference signal (SRS), a demodulation-reference signal (DM-RS), a phase tracking-reference signal (PT-RS), etc. The channel may be a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), etc. In the present disclosure, a control channel may mean a PDCCH, a PUCCH, or a PSCCH, and a data channel may mean a PDSCH, a PUSCH, or a PSSCH.

[0101] Figure 8 is a conceptual diagram illustrating embodiments of time-frequency resources in a communication system.

[0102] Referring to FIG. 8, a resource consisting of one symbol (e.g., an OFDM symbol) in the time domain and one subcarrier in the frequency domain may be defined as a "RE (resource element)". Resources consisting of one OFDM symbol in the time domain and K subcarriers in the frequency domain may be defined as a "REG (resource element group)". A REG may include K REs. A REG may be used as a basic unit for resource allocation in the frequency domain. K may be a natural number. For example, K may be 12. N may be a natural number. In the slot illustrated in FIG. 7, N may be 14. N OFDM symbols may be used as a basic unit for resource allocation in the time domain.

[0103] In the present disclosure, RB may mean CRB (common RB). Alternatively, RB may mean PRB or VRB (virtual RB). In a communication system, CRB may mean RB that constitutes a set of consecutive RBs (e.g., a common RB grid) based on a reference frequency (e.g., point A). Carriers and / or bandwidth portions may be arranged on the common RB grid. That is, the carrier and / or bandwidth portions may be composed of CRB(s). RBs or CRBs that constitute the bandwidth portions may be referred to as PRBs, and within the bandwidth portions, the CRB index may be appropriately converted to the PRB index.

[0104] Downlink data can be transmitted via the PDSCH. The base station can transmit PDSCH configuration information (e.g., scheduling information) to the terminal via the PDCCH. The terminal can obtain the PDSCH configuration information by receiving the PDCCH (e.g., downlink control information (DCI)). For example, the PDSCH configuration information can include the MCS (modulation coding scheme) used for transmitting and receiving the PDSCH, time resource information of the PDSCH, frequency resource information of the PDSCH, feedback resource information for the PDSCH, etc. The PDSCH can refer to a radio resource through which downlink data is transmitted and received. Alternatively, the PDSCH can refer to the downlink data itself. The PDCCH can refer to a radio resource through which downlink control information (e.g., DCI) is transmitted and received. Alternatively, the PDCCH can refer to the downlink control information itself.

[0105] A terminal can perform a monitoring operation on the PDCCH to receive a PDSCH transmitted from a base station. The base station can inform the terminal of the configuration information for the PDCCH monitoring operation using a higher layer message (e.g., an RRC (radio resource control) message). The configuration information for the PDCCH monitoring operation can include CORESET (control resource set) information and search space information.

[0106] CORESET information may include PDCCH DMRS (demodulation reference signal) information, PDCCH precoding information, PDCCH occasion information, etc. The PDCCH DMRS may be a DMRS used to demodulate the PDCCH. The PDCCH occasion may be a region where the PDCCH can exist. That is, the PDCCH occasion may be a region where DCI can be transmitted. The PDCCH occasion may be referred to as a PDCCH candidate. The PDCCH occasion information may include time resource information and frequency resource information of the PDCCH occasion. In the time domain, the length of the PDCCH occasion may be indicated in symbol units. In the frequency domain, the size of the PDCCH occasion may be indicated in RB units (e.g., in PRB (physical resource block) units or CRB (common resource block) units).

[0107] The search space information may include a coreset identifier (ID) associated with the search space, a period of PDCCH monitoring, and / or an offset. The period and offset of PDCCH monitoring may each be indicated on a slot-by-slot basis. In addition, the search space information may further include an index of the symbol at which the PDCCH monitoring operation begins.

[0108] A base station can configure a bandwidth part (BWP) for downlink communication. The BWP can be configured differently for each terminal. The base station can inform the terminal of the BWP configuration information using higher layer signaling. The higher layer signaling can mean "transmission operation of system information" and / or "transmission operation of RRC (radio resource control) message." The number of BWPs configured for one terminal can be one or more. The terminal can receive BWP configuration information from the base station and check the BWP(s) configured by the base station based on the BWP configuration information. When multiple BWPs are configured for downlink communication, the base station can activate one or more BWPs among the multiple BWPs. The base station can transmit the configuration information of the activated BWP(s) to the terminal using at least one of higher layer signaling, a medium access control (MAC) control element (CE), or DCI. The base station can perform downlink communication using the activated BWP(s). The terminal can identify the activated BWP(s) by receiving configuration information of the activated BWP(s) from the base station, and perform a downlink reception operation in the activated BWP(s).

[0109] Meanwhile, a communication system (e.g., NR communication system, 5G communication system, 6G communication system) may support usage scenarios such as enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communication (URLLC), and massive Machine Type Communication (mMTC). A communication system (e.g., a communication network) may support transmission and reception point (TRP) technology (e.g., multiple TRP (mTRP) technology and / or single TRP (sTRP) technology). A communication system supporting the TRP technology may be referred to as a TRP system (e.g., mTRP system and / or sTRP system). In the present disclosure, TRP may have a meaning including sTRP and / or mTRP, and TRP may mean sTRP or mTRP depending on the context. TRP may mean an antenna set, an antenna group, and / or an antenna array. A TRP may be associated with a CORESET and / or a beam (e.g., a beam group).

[0110] mTRP technology may fall under the category of MIMO technology. mTRP may have characteristics (e.g., level characteristics) of macrocells, small cells, picocells, and / or femtocells. mTRP can perform data transmission for a single terminal. In a channel (e.g., a link) with uneven channel conditions due to obstacles and / or interference, mTRP can attenuate the effects of the obstacles and / or interference. mTRP can improve the data transmission rate for terminals located at cell edge areas.

[0111] mTRP-based communication can be performed using either coherent joint transmission (CJT) or non-CJT (NCJT) methods. In CJT, the base station can obtain channel information between each mTRP and the terminal and perform preprocessing on the data based on this channel information. In this case, the overhead associated with transmitting channel information may increase, and synchronization constraints between TRPs may arise. In NCJT, the base station may not need to know the channel information between each mTRP and the terminal. mTRPs can transmit data to the terminal without performing preprocessing operations such as phase compensation. The complexity of NCJT may be lower than that of CJT.

[0112] NCJT-based mTRP communication can be performed based on a single DCI scheme or a multiple DCI scheme. In the single DCI scheme, PDSCHs transmitted by an mTRP can be scheduled by a single DCI. A single DCI can be transmitted by one TRP among the mTRPs. In the multiple DCI scheme, the PDSCHs transmitted by each TRP can be scheduled by the DCI transmitted by each TRP. For example, a first PDSCH transmitted by a first TRP can be scheduled by a first DCI transmitted by the first TRP, and a second PDSCH transmitted by a second TRP can be scheduled by a second DCI transmitted by the second TRP. In other words, multiple PDSCHs can be scheduled using multiple DCIs.

[0113] In a single SCI scheme, a terminal can expect to receive PDSCHs transmitted by different TRPs over the same time and frequency resources and across different layers. Alternatively, the terminal can expect to receive PDSCHs transmitted by different TRPs over the same frequency resources and across the same layer but across different time resources (e.g., across different time domains). Alternatively, the terminal can expect to receive PDSCHs transmitted by different TRPs over the same time resources and across the same layer but across different frequency resources (e.g., across different frequency domains).

[0114] In a multi-DCI scheme, scheduling of PDSCHs for each TRP can be performed by a separate DCI. The PDSCHs scheduled by multiple DCIs may fully overlap or partially overlap. Alternatively, the PDSCHs scheduled by multiple DCIs may not overlap. In both single-DCI and multi-DCI schemes, the DCI may include transmission configuration indicator (TCI) status information for the PDSCH.

[0115] The indication / setting of the TCI state for the terminal can be interpreted as the indication / setting of a beam (e.g., a transmit beam and / or a receive beam). In other words, the TCI state can have a meaning corresponding to the beam. From the perspective of DL (downlink) communication, the setting of the TCI state can mean the setting of QCL (quasi co-location). From the perspective of UL (uplink) communication, the setting of the TCI state can mean the setting of a spatial filter. The unified TCI state can indicate (e.g., set) a common beam regardless of DL communication and UL communication. Alternatively, the unified TCI state can indicate (e.g., set) a common beam for each of DL communication and UL communication. The unified TCI can be referred to as UTCI.

[0116] Enhancements (e.g., PDCCH enhancements) may be implemented to improve the reliability and / or robustness of mTRP communications. Deployment scenarios for PDCCH enhancements can be categorized into single frequency network (SFN) and non-SFN scenarios.

[0117] In the SFN scheme, different TRPs or different panels can transmit the same PDCCH using the same resources (e.g., the same time resources, the same frequency resources, and / or the same spatial resources). In other words, all TRPs or all panels can transmit the same PDCCH using the same DMRS configuration, the same DMRS location, and / or the same DMRS sequence. At this time, the TCI states for the reception perspective of the TRPs or panels can be implicitly set differently. The above embodiment can be performed based on multiple TCI states of the CORESET. There may be synchronization constraints for ideal or near-ideal backhaul between TRPs.

[0118] In the NSFN scheme, the PDCCH generated from each TRP can be multiplexed in the time domain and / or frequency domain, and the multiplexed PDCCH can be transmitted to the terminal. The scheme may be an mTRP-based PDCCH repetition scheme. In the NSFN scheme, the same number of bits as the encoded bits transmitted through one PDCCH generated from each TRP can be divided for each TRP, and the bits (e.g., encoded bits) for each TRP can be transmitted through different PDCCH candidates. The scheme may be an sTRP-based PDCCH transmission scheme.

[0119] In the mTRP-based PDCCH repetition scheme, the PDCCH can be repeatedly generated as many times as the number of TRPs, and the PDCCH can be transmitted in the same search space (e.g., search spaces having the same index) within different search space sets having the same number of PDCCH candidates. At this time, the search space sets can exist within the same CORESET or different CORESETs. Since one TCI state can be associated with each CORESET, when the PDCCH is transmitted in different search spaces within the same CORESET, only one TCI state can be indicated (e.g., set) for the PDCCHs transmitted in the different search spaces. In this case, the UE can receive the PDCCH from one TRP at a specific time.

[0120] When a PDCCH is transmitted in the same search space within different CORESETs, the UE can implicitly expect to receive the PDCCH from either the sTRP or the mTRP, depending 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 split as many times as the number of TRPs, and the split PDCCHs can be transmitted on different PDCCH candidates. At this time, the aggregation level and the combined aggregation level can be the same. In the above embodiment, the PDCCH candidates can be assigned to different CORESETs. The payload size for the final distributed PDCCH combination can be the same as the payload size of the PDCCH transmitted in the sTRP. Therefore, in terms of decoding complexity, the sTRP-based PDCCH transmission scheme can be advantageous over the mTRP-based PDCCH repetition scheme.

[0121] A terminal can perform mTRP communication or sTRP communication with a base station. mTRP communication between the terminal and the base station can be performed through an mTRP associated with the base station. sTRP communication between the terminal and the base station can be performed through an sTRP associated with the base station. mTRP communication may be referred to as first TRP communication, and sTRP communication may be referred to as second TRP communication. Alternatively, mTRP communication may be referred to as second TRP communication, and sTRP communication may be referred to as first TRP communication. "The terminal performs first TRP communication with the base station" may mean "the terminal performs mTRP communication or sTRP communication with the base station through one or more TRPs associated with the base station." "The terminal performs second TRP communication with the base station" may mean "the terminal performs sTRP communication or mTRP communication with the base station through one or more TRPs associated with the base station."

[0122] In a communication system, integrated TCI can be supported. A base station can transmit information about a pool (e.g., a list) of TCI states to a terminal using RRC signaling. The terminal can receive information about a pool (e.g., a list) of TCI states through RRC signaling from the base station. The base station can set type information about the TCI state to the terminal. The type information can be a joint DL / UL beam indication or a separate DL / UL beam indication. A joint DL / UL beam indication can be referred to as a 'joint indication or joint type.' An independent DL / UL beam indication can be referred to as an 'independent indication or independent type.'

[0123] When a joint type (e.g., joint indication) is set, TCI states (e.g., one TCI state) for DL ​​and UL may be set. In other words, DL TCI state setting and UL TCI state setting may be the same. The UE may expect that the TCI state indicated by the information element included in the PDSCH configuration information applies to both DL (e.g., DL signal / channel) and UL (e.g., UL signal / channel). The signal / channel may refer to a signal and / or a channel. When an independent type (e.g., independent indication) is set, TCI states for DL ​​and UL may be set respectively. In other words, DL TCI state setting may be distinguished from UL TCI state setting. The UE may expect that the UL TCI state indicated by the information element included in the UL BWP configuration information applies to UL (e.g., UL signal / channel). The UL signal / channel may include a PUSCH, a PUCCH, and / or an SRS.

[0124] After the pool (e.g., pool list) for TCI states is configured (e.g., indicated) by RRC signaling, the base station can use DCI (e.g., DCI signaling) to indicate the TCI state (e.g., application of the TCI state). Due to the constraint of the DCI size (e.g., bits in the DCI field), the base station can preferentially activate candidate TCI state(s) using MAC signaling (e.g., MAC CE signaling). In other words, as many (e.g., maximum number) candidate TCI state(s) as can be indicated (e.g., configured) via DCI can be preferentially activated by MAC CE.

[0125] For the activated candidate TCI state(s), the DCI may contain code points corresponding to a single TCI state or two TCI states, depending on the TCI state type (e.g., joint type or independent type). If the joint type is set, the code points corresponding to a single TCI state may be conveyed by the DCI. If the independent type is set, the code points corresponding to two TCI states may be conveyed by the DCI.

[0126] Meanwhile, intra-cell mTRP or inter-cell mTRP may support an RA procedure based on a cross-PDCCH order. The RA procedure may include a contention-free random access (CFRA) procedure and / or a contention-based random access (CBRA) procedure. In a signaling procedure for a cross-TRP RA, a TCI status indication may be required for transmitting and receiving signals between a UE and a TRP. In the present disclosure, a signal may mean a signal or a channel. In addition, a signal may be used in a comprehensive sense of "signal + channel." In a cross-PDCCH order-based RA procedure, a UE may receive a PDCCH order from a first TRP and transmit an RA preamble to a second TRP based on the PDCCH order. In other words, the UE may perform an RA procedure initiated by the PDCCH order of the first TRP with the second TRP. The PDCCH order for the RA procedure based on the cross-PDCCH order may be referred to as a cross-PDCCH order. In the present disclosure, the PDCCH order may be interpreted as a cross-PDCCH order depending on the context. The RA procedure may be a four-step RA procedure or a two-step RA procedure.

[0127] For an RA procedure between a terminal and a TRP, information about the beam used for communication between the terminal and the TRP (e.g., a TCI status indication) may be indicated (e.g., set) to the terminal before performing the RA procedure. In the RA procedure, signals (e.g., messages) may be transmitted and received through different TRPs. In this case, additional TCI status indication(s) may be required for transmitting and receiving signals. In other words, a signaling method for the TCI status indication may be required for cross-TRP RA operation. In addition to the signaling method for the TCI status indication, a signaling method for other information may be required for cross-TRP operation.

[0128] SSB (synchronization signal block) transmission settings, RO (random access occasion) settings, and / or association settings between SSB and RO (e.g., association settings for beam information) can be configured (e.g., indicated, operated) cell-specifically. Since the above settings are operated cell-specifically, in an mTRP system (e.g., an mTRP communication system), a terminal cannot recognize a TRP that transmitted an SSB. A previous SSB transmission can be performed through a specific TRP, and the terminal can obtain beam configuration information for the RO based on the SSB received through the specific TRP. In the above situation, the terminal can perform a second TRP and an RA procedure based on a cross-PDCCH order received from the first TRP. The cross-PDCCH order can indicate RO information. The cross-PDCCH order may include beam configuration information, and the beam configuration information may be for a specific TRP (e.g., the first TRP) that transmitted the previous SSB, rather than the second TRP that is the target of the RA procedure. In this case, ambiguity regarding beam configuration may arise in the RA procedure. RO may refer to a physical random access channel (PRACH) occasion or a random access channel (RACH) occasion.

[0129] In a signaling procedure for a cross-TRP RA, a signaling method for a TCI status indication may be required for an RA procedure between a terminal and a TRP. The TCI status indication may be used to indicate a TRP that transmits and receives signals (e.g., messages) with the terminal. The TCI status indication may be used to indicate a TRP that performs an RA procedure with the terminal. In the present disclosure, signaling methods for a cross-TRP RA will be described. The signaling methods may include a signaling method for a TCI status indication for a cross-TRP RA.

[0130] Embodiments of the present disclosure may be applied to single DCI-based mTRP communication and / or multi-DCI-based mTRP communication. While embodiments of the present disclosure will be described based on a communication system including two TRPs, embodiments of the present disclosure may also be applied to a communication system including three or more TRPs. In the present disclosure, a TRP that transmits a PDCCH order indicating the initiation (e.g., execution) of an RA procedure may be referred to as TRPx (or a first TRP), and a TRP that is a target of execution of the RA procedure initiated by the PDCCH order may be referred to as TRPy (or a second TRP). TRPy may receive an RA preamble from a terminal and determine (e.g., measure) a timing advance (TA) based on the RA preamble. The TA may be determined at a base station connected to TRPy. TRPx (or the first TRP) and TRPy (or the second TRP) may refer to different TRPs. TRPx and TRPy may be connected to different base stations. Alternatively, TRPx and TRPy may be connected to the same base station. TRPx and TRPy may also refer to the same TRP.

[0131] 1. CFRA procedure based on cross-PDCCH order

[0132] 1.1 Method #1

[0133] Figure 9 is a flowchart illustrating a CFRA procedure based on cross-PDCCH order.

[0134] Referring to FIG. 9, TRPx can transmit a PDCCH order to a terminal (S901). The PDCCH order can be generated at a base station to which TRPx is connected. The base station can transmit the PDCCH order to the terminal through TRPx. The PDCCH order can include at least one of dedicated preamble information or RO information. The PDCCH order can include information indicating a target of an RA procedure (e.g., information indicating TRPy, TCI status indication for TRPy, etc.). The PDCCH order can include information indicating that the PDCCH order is a cross-PDCCH order. The PDCCH order can include information indicating that a cross-TRP RA procedure is initiated.

[0135] The terminal can receive a PDCCH order from TRPx (S901). The terminal can check information (e.g., indication information) included in the PDCCH order, and transmit a message (e.g., Msg1 or MsgA) including an RA preamble to TRPy based on the checked information (S902). For example, the terminal can generate an RA preamble based on dedicated preamble information included in the PDCCH order, and transmit the RA preamble to TRPy in an RO indicated by the RO information included in the PDCCH order. The RA preamble may 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 order.

[0136] Msg1 (or MsgA) may be an RA request message. Transmitting Msg1 (or MsgA) may mean transmitting a dedicated RA preamble in a specific time / frequency resource (e.g., RO). TRPy may receive Msg1 (or MsgA) from a terminal (S902). Upon receiving Msg1 (or MsgA), TRPy may generate Msg2 (or MsgB). Msg2 (or MsgB) may be a random access response (RAR) message. TRPy may determine a TA based on Msg1 (or MsgA), and the TA may be included in Msg2 (or MsgB). The TA may be determined by the base station to which TRPy is connected instead of TRPy. TRPy can transmit Msg2 (or MsgB) to the terminal (S903). In other words, the base station can transmit Msg2 (or MsgB) to the terminal via TRPy.

[0137] The terminal can receive Msg2 (or MsgB) from TRPy (S903). The terminal can check information (e.g., TA) included in Msg2 (or MsgB). The terminal can perform uplink transmission using TA. The uplink transmission can be performed for at least one of TRPx or TRPy. In the present disclosure, Msg1 can be interpreted as MsgA depending on the context, MsgA can be interpreted as Msg1, Msg2 can be interpreted as MsgB depending on the context, and MsgB can be interpreted as Msg2. In other words, the method for the 4-step RA procedure proposed in the present disclosure can be applied to the 2-step RA procedure in the same or similar manner, and the method for the 2-step RA procedure proposed in the present disclosure can be applied to the 4-step RA procedure in the same or similar manner.

[0138] In FIG. 9, the PDCCH order may be transmitted for the purpose of cross-TRP RA. In other words, the PDCCH order of TRPx may be transmitted for the purpose of performing an RA procedure for TRPy. Alternatively, the PDCCH order of TRPx may be transmitted for the purpose of performing an RA procedure for TRPx. The PDCCH order may explicitly or implicitly include information (e.g., indication information) indicating a TRP that is a target of the RA procedure initiated by the PDCCH order. The PDCCH order may include TCI state information for communication with the TRP. When the PDCCH order of TRPx indicates initiation of an RA procedure for TRPy, the PDCCH order may include indication information (e.g., TCI state information) regarding a beam used for the RA procedure (e.g., RA preamble transmission) for TRPy.

[0139] 1.1.1 Instruction Style #1

[0140] A PDCCH order may include a TAG (timing advance group) identifier (ID) (e.g., a TAG ID field) indicating a TRP that is a target of an RA procedure initiated by the PDCCH order. The TAG ID may be set to be associated with a TCI state (e.g., a UL / joint TCI state or a DL / joint TCI state). The UL / joint TCI state may be associated with a CORESET pool index (e.g., CORESETpoolindex). In other words, the TCI state may be associated with a CORESET pool. The TAG ID may be set to be associated with a CORESET (or a CORESET pool to which the CORESET belongs). Since the CORESET pool can be set per TRP (e.g., TCI state), the TRP that is the target of the RA procedure initiated by the PDCCH order can be identified based on the "TAG ID - UL / Joint TCI state association" or the "TAG ID - UL / Joint TCI state - CORESET pool association."

[0141] In other words, the TAG ID included in the PDCCH order can indicate the TRP that is the target of the RA procedure and / or the TCI state used for the RA procedure. The UL / joint TCI state can be set to the UE by signaling from the base station (e.g., RRC signaling). If the UL / joint TCI state is not set, the UE can assume that the TAG ID is associated with the DL / joint TCI state. The reserved bit(s) included in the PDCCH order can be used to indicate the TAG ID. Alternatively, one field (e.g., the FDRA (frequency domain resource allocation) field) or a combination of two or more fields included in the PDCCH order can be used to indicate the TAG ID.

[0142] 1.1.2 Instruction Style #2

[0143] A PDCCH order may include TCI state information (e.g., a TCI field) indicating a TRP that is a target of an RA procedure initiated by the PDCCH order. A TCI state (e.g., a UL / joint TCI state) indicated by the TCI state information may be associated with a TAG ID and / or a CORESET full index. The TCI state information included in the PDCCH order may indicate a TRP that is a target of an RA procedure. The TCI state information included in the PDCCH order may indicate a TCI state used for an RA procedure (e.g., signaling for the RA procedure). Reserved bit(s) included in the PDCCH order may be used to indicate the TCI state. The TCI states may be set to the terminal by RRC signaling of the base station, and one or more of the TCI states set by the RRC signaling may be activated by a MAC CE. The TCI state information included in the PDCCH order may indicate at least one TCI state among one or more TCI states activated by the MAC CE.

[0144] In the RA procedure illustrated in FIG. 9, the terminal may perform uplink communication and / or downlink communication with TRPy. Uplink communication may refer to transmission of Msg1, and downlink communication may refer to reception of Msg2. The terminal may perform TRPy and the RA procedure based on a TCI state indicated by indication method #1 or #2. The TCI state indicated by indication method #1 or #2 may be a joint TCI state or an UL TCI state. The UL TCI state may be paired with a DL TCI state.

[0145] 1.1.3 Instruction Style #3

[0146] A PDCCH order may include a TAG ID and TCI state information to indicate a TRP that is a target of an RA procedure initiated by the PDCCH order. In other words, the TAG ID and TCI state information may be used to indicate a TRP that is a target of an RA procedure. If one TCI state is associated with two or more TAG IDs, a UE may not be able to determine which TAG TA's update is indicated based solely on the TCI state information. In this case, both the TAG ID and the TCI state information may be required to indicate a TRP that is a target of an RA procedure. Identical to or similar to the indication method #1 and / or the indication method #2, the reserved bit(s) included in the PDCCH order may be used to indicate the TAG ID and TCI state information.

[0147] 1.1.4 Instruction Style #4

[0148] Dedicated preamble(s) for the CFRA procedure can be configured per TRP (e.g., 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 can include one or more dedicated preambles (e.g., one or more RA preambles). The base station can signal (e.g., instruct) the terminal to configure the dedicated preamble group #0 associated with CORESET pool #0 and / or the dedicated preamble group #1 associated with CORESET pool #1. 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 the present disclosure, signaling may be at least one of SI (system information) signaling, RRC signaling, MAC CE signaling, or PHY signaling (e.g., DCI).

[0149] The PDCCH order may include information indicating an RA preamble (e.g., a dedicated preamble). The UE may identify the dedicated preamble group to which the RA preamble indicated by the PDCCH order belongs. If the dedicated preamble group to which the RA preamble belongs is dedicated preamble group #0, the UE may perform a CFRA procedure based on the TCI state associated with CORESET pool #0 associated with dedicated preamble group #0. In other words, the UE may perform TRP and CFRA procedures associated with CORESET pool #0 associated with dedicated preamble group #0.

[0150] 1.1.5 Instruction Style #5

[0151] RO(s) (e.g., dedicated RO(s)) for CFRA procedure can be configured per TRP (e.g., TCI state). For example, dedicated RO group #0 associated with CORESET pool #0 can be configured, and dedicated RO group #1 associated with CORESET pool #1 can be configured. Each dedicated RO group can include one or more dedicated ROs. The base station can configure (e.g., instruct) the terminal to configure (e.g., instruct) the terminal to configure the dedicated RO group #0 associated with CORESET pool #0 and / or the dedicated RO group #1 associated with CORESET pool #1 by 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.

[0152] A PDCCH order may include information indicating an RO (e.g., a dedicated RO). The UE may identify the dedicated RO group to which the dedicated RO indicated by the PDCCH order belongs. If the dedicated RO group to which the dedicated RO belongs is dedicated RO group #0, the UE may perform a CFRA procedure based on the TCI status associated with CORESET pool #0 associated with dedicated RO group #0. In other words, the UE may perform TRP and CFRA procedures associated with CORESET pool #0 associated with dedicated RO group #0.

[0153] 1.1.5 Instruction Style #6

[0154] TRPs may belong to different cells. In this case, an inter-cell cross-TRP RA procedure may be performed. TRPs belonging to different cells may have different physical cell identifiers (PCIs). In order to indicate a TRP that is a target of the RA procedure in the above situation, the PDCCH order may include an ID (e.g., a cell ID) associated with the PCI and / or the cell. The ID associated with the PCI and / or the cell may indicate a TRP that is a target of the RA procedure. The UE may perform an RA procedure (e.g., transmit an RA preamble) with a TRP that belongs to a cell having the ID included in the PDCCH order.

[0155] The above ID (e.g., an ID associated with a PCI and / or a cell) may be associated with a PRACH configuration (e.g., a RACH configuration). For example, the PRACH configuration information (e.g., RACH configuration information) may include an ID associated with a PCI and / or a cell, and an RA procedure for TRP(s) indicated by the ID associated with the PCI and / or the cell may be performed based on the PRACH configuration information. The base station may transmit the PRACH configuration information to the terminal. The terminal may receive the PRACH configuration information from the base station and perform the TRP(s) and the RA procedure based on the PRACH configuration information. For example, the terminal may perform the TPR(s) and the RA procedure indicated by the ID included in the PRACH configuration information.

[0156] PRACH configuration information may be associated with one TCI state or two or more TCI states. The base station may instruct (e.g., configure) the association information (e.g., mapping information) between the PRACH configuration information and the TCI state(s) to the terminal through signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal may receive the association information between the PRACH configuration information and the TCI state(s) from the base station, identify the TCI state(s) associated with the PRACH configuration information, and perform TRP(s) and RA procedures based on the identified TCI state(s).

[0157] The base station can set "the mapping relationship between PRACH configuration information - TCI state", "the mapping relationship between PRACH configuration information - TAG ID", and / or "the mapping relationship between PRACH configuration information - TCI state - TAG ID", and can indicate (e.g., set) information of the mapping relationship to the terminal through signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal can receive information of the mapping relationship from the base station. The base station (e.g., a TRP connected to the base station) can transmit a PDDCH order including TCI state information (e.g., a TCI state indication) and / or a TAG ID (e.g., a TAG ID indication) to the terminal. The TCI state information and / or the TAG ID can indicate a TRP that is a target of performing an RA procedure. The terminal can receive the PDCCH order from the base station and check information included in the PDCCH order. The terminal can identify a TRP that is a target of an RA procedure based on TCI status information and / or TAG ID included in a PDCCH order, and can perform the identified TRP and the RA procedure.

[0158] Each of Instruction Schemes #1 to #6 can be applied to a CFRA procedure based on a cross-PDCCH order. A combination of two or more Instruction Schemes #1 to #6 can be applied to a CFRA procedure based on a cross-PDCCH order. Modified and / or extended methods of Instruction Schemes #1 to #6 can be applied to a CFRA procedure based on a cross-PDCCH order.

[0159] Figure 10 is a flowchart illustrating a CFRA procedure based on cross-PDCCH order.

[0160] Referring to FIG. 10, TRPx can transmit a PDCCH order to a terminal (S1001). The PDCCH order can be generated at a base station to which TRPx is connected. The base station can transmit the PDCCH order to the terminal through TRPx. The PDCCH order can include at least one of dedicated preamble information or RO information. The PDCCH order can include information indicating a target of an RA procedure (e.g., information indicating TRPy, TCI status indication for TRPy, etc.). The PDCCH order can include information indicating that the PDCCH order is a cross-PDCCH order. The PDCCH order can include information indicating that a cross-TRP RA procedure is initiated.

[0161] The terminal can receive a PDCCH order from TRPx (S1001). The terminal can check the information included in the PDCCH order, and based on the checked information, transmit Msg1 (or MsgA) including an RA preamble to TRPy (S1002). For example, the terminal can generate an RA preamble based on dedicated preamble information included in the PDCCH order, and transmit the RA preamble to TRPy in an RO indicated by the RO information included in the PDCCH order. The RA preamble can be an RA preamble for Msg1 or MsgA. In other words, the terminal can perform a 4-step RA procedure or a 2-step RA procedure based on the PDCCH order.

[0162] Msg1 may be an RA request message. Transmission of Msg1 may mean transmitting a dedicated RA preamble on a specific time / frequency resource (e.g., RO). TRPy may receive Msg1 (or MsgA) from a terminal (S1002). TRPy, having received Msg1, may generate information necessary for generating Msg2 (or MsgB). Msg2 (or MsgB) may be a RAR message. The information necessary for generating the RAR message may include TA information measured by TRPy. TRPy may determine the TA based on Msg1 received from the terminal and generate TA information including the determined TA. The TA may be determined by a base station connected to TRPy. The information necessary for generating the RAR message may include an RNTI (radio network temporary identifier) ​​determined by TRPy. RNTI can be used for transmission of Msg2.

[0163] Information required for generating a RAR message may be defined as RAR configuration information. TRPy may transmit the RAR configuration information to TRPx (S1003). TRPx may receive the RAR configuration information from TRPy (S1003). S1003 may be a sharing step of RAR configuration information (e.g., TA information). The RAR configuration information may include at least one of TA information, information required for determining TA, RNTI for transmitting Msg2, or information required for determining RNTI for transmitting Msg2. TRPy may determine TA based on Msg1 received from the terminal, and transmit the determined TA information to TRPx in S1003. Alternatively, the TA for the terminal may be determined in TRPx instead of TRPy, and to support the above operation, TRPy may transmit information required for determining TA to TRPx in S1003. TRPy can determine an RNTI based on resource information of the RO in which Msg1 of the terminal is received, and transmit the determined RNTI to TRPx in S1003. Alternatively, the RNTI for transmitting Msg2 can be determined in TRPx instead of TRPy, and to support the above operation, TRPy can transmit information necessary for determining the RNTI to TRPx in S1003.

[0164] TRPx can generate Msg2 (or MsgB) based on the RAR configuration information received from TRPy, and transmit Msg2 to the terminal (S1004). In other words, the base station can transmit Msg2 to the terminal through TRPx. Msg2 can include TA information for the terminal. For example, TRPx can determine TA based on information necessary for determining TA included in RAR configuration information, and can determine RNTI based on information necessary for determining RNTI for transmitting Msg2 included in RAR configuration information. Msg2 can include TA information for TRPx and / or TA information for TRPy. The terminal can receive Msg2 from TRPx, and check information (e.g., TA information) included in Msg2. The terminal can perform uplink communication based on the TA indicated by Msg2.

[0165] In intra-cell mTRP communication, S1003 (e.g., TA sharing operation) may be performed by the base station to which the TRPs are connected. In inter-cell mTRP communication, S1003 (e.g., TA sharing operation) may be performed via an interface between the base stations to which the TRPs are connected. The above-described TA sharing operation may be applied identically or similarly in embodiments of the present disclosure.

[0166] In FIG. 10, a PDCCH order may be transmitted to initiate an RA procedure for a cross-TRP (e.g., TRPy). Alternatively, the PDCCH order may be transmitted to initiate an RA procedure for TRPx. The PDCCH order may include information (e.g., indication information) indicating the TRP (e.g., TRPx or TRPy) that is the target of initiation (e.g., execution) of the RA procedure. The TRP that is the target of initiation of the RA procedure may be explicitly or implicitly indicated by the PDCCH order.

[0167] The PDCCH order may include information indicating a TRP (e.g., TRPx or TRPy) that is a transmission subject of Msg2 (or MsgB). In the embodiment of FIG. 9, the initiation target of an RA procedure (e.g., transmission operation of Msg1) indicated by the PDCCH order may be TRPy, and the transmission subject of Msg2 indicated by the PDCCH order may be TRPy. In the embodiment of FIG. 10, the initiation target of an RA procedure (e.g., transmission operation of Msg1) indicated by the PDCCH order may be TRPy, and the transmission subject of Msg2 indicated by the PDCCH order may be TRPx.

[0168] Each of Instruction Schemes #1 to #6 can be applied to the embodiment of FIG. 10 (e.g., a cross-PDCCH order-based CFRA procedure). A combination of two or more of Instruction Schemes #1 to #6 can be applied to the embodiment of FIG. 10. Modified and / or extended methods for Instruction Schemes #1 to #6 can be applied to the embodiment of FIG. 10.

[0169] In the RA procedure of the embodiment of FIG. 10, the terminal can perform uplink transmission for TRPy. Accordingly, the TCI state indicated by indication method #1 and / or indication method #2 may be a joint / UL TCI state.

[0170] One of the embodiments of FIG. 9 (hereinafter referred to as RA method #1) and FIG. 10 (hereinafter referred to as RA method #2) may be performed in a communication system. When both RA method #1 and RA method #2 are applicable to the communication system, a method of indicating which of RA method #1 and RA method #2 is actually used may be necessary. Which of RA method #1 and RA method #2 is actually used may be determined according to the configuration of a type 1 CSS (common search space) associated with a CORESET pool index. In the RA procedure, a DCI for scheduling transmission of Msg2 (e.g., an RAR message) may be transmitted in the type 1 CSS. Therefore, Msg2 may be transmitted through a TRP associated with the CORESET pool to which the CORESET to which the type 1 CSS is configured belongs. A terminal may expect to receive Msg2 (e.g., an RAR message) from a TRP associated with the CORESET pool to which the type 1 CSS is configured belongs. The RA mode (e.g., RA mode #1 or RA mode #2) can be indicated by a type 1 CSS setting.

[0171] Meanwhile, in a communication system in which TRP #0 and TRP #1 exist, TCI state information for TRP #0 may be associated with CORESET pool #0, and TCI state information for TRP #1 may be associated with CORESET pool #1. The PDCCH (e.g., PDCCH order) of TRP #0 may be transmitted through a CORESET associated with (e.g., belongs to) CORESET pool #0, and the PDCCH of TRP #1 may be transmitted through a CORESET associated with (e.g., belongs to) CORESET pool #1. Each of TRP #0 and TRP #1 may be one of the above-described TRPs TRPx and TRPy. For example, TRP #0 may be TRPx, and TRP #1 may be TRPy. Alternatively, TRP #0 may be TRPy, and TRP #1 may be TRPx.

[0172] In the above situation, if Type 1 CSS is set only in the CORESET associated with CORESET pool #0, RAR messages (e.g., Msg2, MsgB) can be transmitted only via TRP #0. Conversely, if Type 1 CSS is set only in the CORESET associated with CORESET pool #1, RAR messages can be transmitted only via TRP #1. For another example, if Type 1 CSS is set in the CORESETs associated with 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 that transmits the RAR message based on the Type 1 CSS setting, and can expect to receive the RAR message from the identified TRP. The TRP that transmits the RAR message can be determined based on the Type 1 CSS setting. Which of RA method #1 and RA method #2 is actually used can be indicated by the Type 1 CSS setting.

[0173] A TRP for transmitting a PDCCH order (e.g., a cross-PDCCH order) in RA scheme #1 and / or RA scheme #2 may be configured (e.g., indicated). In a communication system where TRP #0 and TRP #1 exist, TCI state information for TRP #0 may be associated with CORESET pool #0, and TCI state information for TRP #1 may be associated with CORESET pool #1. The PDCCH (e.g., PDCCH order) of TRP #0 may be transmitted via a CORESET associated with (e.g., belongs to) CORESET pool #0, and the PDCCH (e.g., PDCCH order) of TRP #1 may be transmitted via a CORESET associated with (e.g., belongs to) CORESET pool #1.

[0174] A CORESET (e.g., a CORESET configuration) capable of transmitting a PDCCH order (e.g., a cross-PDCCH order) can be associated with a specific CORESET pool (e.g., a specific CORESET pool index). The PDCCH order can be interpreted as a cross-PDCCH order depending on the context. For example, the base station can configure that the PDCCH order (e.g., a cross-PDCCH order) is transmitted through CORESET(s) associated with CORESET pool #0, and can instruct the terminal of the configuration through signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal can perform a monitoring operation (e.g., a receiving operation) for the PDCCH order in the CORESET(s) according to the configuration.

[0175] Conversely, the base station may configure that the PDCCH order (e.g., cross-PDCCH order) is transmitted via CORESET(s) associated with CORESET pool #1, and may indicate the configuration to the terminal via signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal may perform a monitoring operation (e.g., receiving operation) for the PDCCH order in the CORESET(s) according to the configuration. As another example, the base station may configure that the PDCCH order (e.g., cross-PDCCH order) is transmitted via CORESET(s) associated with CORESET pool #0 and CORESET pool #1, and may 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 a monitoring operation (e.g., a receiving operation) for the PDCCH order in the CORESET(s) according to the above settings.

[0176] In a communication system, either RA scheme #1 or RA scheme #2 can be used. In a communication system, both RA schemes #1 and #2 can be used, and one RA scheme to be actually used can be indicated to the terminal. The RA scheme used may vary depending on the communication scenario (e.g., communication environment). For example, in an inter-cell mTRP scenario, RA scheme #1 (e.g., the embodiment of FIG. 9) can be applied, and in an intra-cell mTRP scenario, RA scheme #2 (e.g., the embodiment of FIG. 10) can be applied.

[0177] 2. CBRA procedure based on cross-PDCCH order

[0178] A CBRA procedure may be a RA procedure initiated by a terminal. To support a cross-TRP RA procedure, a cross-PDCCH order-based CBRA procedure may be supported (e.g., operated). If a dedicated preamble is not configured in the terminal, the CBRA procedure may be performed instead of the CFRA procedure. The terminal may obtain TA information for a specific TRP by performing the CBRA procedure. To support the above operation, information for performing the RA procedure with a specific TRP may be required. Similar to or identical to the cross-PDCCH order-based CFRA procedure described above, the CBRA procedure may be performed based on a specific triggering signal. Similar to or identical to the cross-PDCCH order-based CFRA procedure described above, the specific triggering signal for the CBRA procedure may be defined as a PDCCH order. The PDCCH order in the cross-PDCCH order-based CBRA procedure may be identical to the PDCCH order in the cross-PDCCH order-based CFRA procedure. Alternatively, in a CBRA procedure based on cross-PDCCH order, the PDCCH order may be a modified or extended form of the PDCCH order in a CFRA procedure based on cross-PDCCH order.

[0179] A PDCCH order for a CBRA procedure based on a cross-PDCCH order may include a TAG ID associated with a specific TRP to indicate TA measurement for the specific TRP. To provide RO information (e.g., RO configuration information) associated with the TRP, the PDCCH order may include RO information. The PDCCH order may include configuration information for an SSB (e.g., an SSB group) transmitted by the TRP. A terminal may receive an SSB based on the configuration information for the SSB and identify an RO associated with the SSB. The RO may be determined based on a measurement result of the SSB. The terminal may receive a PDCCH order from a TRP and perform an RA procedure initiated (e.g., triggered) by the PDCCH order. The terminal may perform a four-step RA procedure or a two-step RA procedure. In the RA procedure, the terminal may transmit Msg1 or MsgA to a TRP that is a target of TA measurement. The PDCCH order may include TCI status information for the RA procedure with the TRP, which is the measurement target of the TA. The TCI status information may be provided to the terminal to indicate information about the beam used for transmitting the RA preamble (e.g., Msg1 or MsgA) in the RA procedure.

[0180] The TAG ID may be associated with a joint / UL TCI state. In this case, the TAG ID and / or TCI state information (e.g., a TCI state indication) may be used to indicate the TRP that is the target of the RA procedure and / or beam information used to transmit the RA preamble to the TRP. The PDCCH order may include the TAG ID and / or TCI state information.

[0181] TCI status information can be explicitly or implicitly indicated by the PDCCH order. In a CBRA procedure based on a cross-PDCCH order, a terminal can perform an RA procedure without performing an SSB reception operation (e.g., a beam sweeping-based SSB reception operation), and can obtain TA information through the RA procedure.

[0182] 2.1 4-Step CBRA Procedure

[0183] Figures 11 to 15 are flowcharts illustrating a four-step CBRA procedure based on cross-PDCCH order.

[0184] Referring to FIGS. 11 to 15, the 4-step CBRA procedure can be triggered (e.g., initiated) by a cross-PDCCH order. The messages transmitted in the 4-step CBRA procedure 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 transmitted and received for contention resolution. The UL grant for Msg3 can be transmitted via Msg2.

[0185] In the embodiment of FIG. 11, TRPx can transmit a PDCCH order to the terminal (S1101). In other words, the base station can transmit the PDCCH order to the terminal via TRPx. The terminal can receive the PDCCH order from TRPx (S1101). The terminal can perform an RA procedure initiated by the PDCCH order with TRPy (S1102, S1103, S1104, S1105). S1102 may be a procedure for transmitting and receiving Msg1 between the terminal and TRPy. In S1102, the terminal can transmit Msg1 to TRPy, and TRPy can receive Msg1 from the terminal. S1103 may be a procedure for transmitting and receiving Msg2 between the terminal and TRPy. At S1103, TRPy can transmit Msg2 to the terminal, and the terminal can receive Msg2 from TRPy. S1104 may be a procedure for transmitting and receiving Msg3 between the terminal and TRPy. At S1104, the terminal can transmit Msg3 to TRPy, and TRPy can receive Msg3 from the terminal. S1105 may be a procedure for transmitting and receiving Msg4 between the terminal and TRPy. At S1105, TRPy can transmit Msg4 to the terminal, and the terminal can receive Msg4 from TRPy.

[0186] In the embodiment of FIG. 12, TRPx can transmit a PDCCH order to the terminal (S1201). In other words, the base station can transmit the PDCCH order to the terminal through TRPx. The terminal can receive the PDCCH order from TRPx (S1201). The terminal can perform an RA procedure initiated by the PDCCH order (S1202, S1204, S1205, S1206). In the RA procedure, the transmission and reception procedure of Msg1 can be performed between the terminal and TRPy, and the transmission and reception procedures of Msg2, Msg3, and Msg4 can be performed between the terminal and TRPx. S1202 can be a transmission and reception procedure of Msg1 between the terminal and TRPy. In S1202, the terminal can transmit Msg1 to TRPy, and TRPy can receive Msg1 from the terminal.

[0187] TRPy, which receives Msg1, can generate information necessary for generating Msg2 (e.g., an RAR message). The information necessary for generating Msg2 can be generated at a base station to which TRPy is connected. The information necessary for generating the RAR message can include TA information measured by TRPy. TRPy can determine TA based on Msg1 received from a terminal and generate TA information including the determined TA. The information necessary for generating the RAR message can include an RNTI determined by TRPy. The information necessary for generating the RAR message can be defined as RAR configuration information. In S1203, TRPy can transmit RAR configuration information to TRPx, and TRPx can receive RAR configuration information from TRPy. S1203 can be a sharing step of RAR configuration information (e.g., TA information). The RAR configuration information may include at least one of TA information, information required for determining TA, RNTI for Msg2 transmission, or information required for determining RNTI for Msg2 transmission. S1203 may be performed identically or similarly to S1003 illustrated in FIG. 10.

[0188] S1204 may be a procedure for transmitting and receiving Msg2 between the terminal and TRPx. In S1204, TRPx may transmit Msg2 to the terminal, and the terminal may receive Msg2 from TRPx. S1205 may be a procedure for transmitting and receiving Msg3 between the terminal and TRPx. In S1205, the terminal may transmit Msg3 to TRPx, and TRPx may receive Msg3 from the terminal. S1206 may be a procedure for transmitting and receiving Msg4 between the terminal and TRPx. In S1206, TRPx may transmit Msg4 to the terminal, and the terminal may receive Msg4 from TRPx.

[0189] The embodiment of FIG. 13 can be performed in the same manner as the embodiment of FIG. 12, except for the transmission and reception procedures of Msg4. S1301, S1302, S1303, S1304, and S1305 can each be performed in the same manner as S1201, S1202, S1203, S1204, and S1205. In S1306, TRPy can transmit Msg4 to the terminal, and the terminal can receive Msg4 from TRPy.

[0190] The embodiment of FIG. 14 can be performed in the same manner as the embodiment of FIG. 12, except for the transmission and reception procedures of Msg3 and Msg4. S1401, S1402, S1403, and S1404 can each be performed in the same manner as S1201, S1202, S1203, and S1204. In S1405, the terminal can transmit Msg3 to TRPy, and TRPy can receive Msg3 from the terminal. In S1406, TRPy can transmit Msg4 to the terminal, and the terminal can receive Msg4 from TRPy.

[0191] The embodiment of FIG. 15 can be performed in the same manner as the embodiment of FIG. 12, except for the transmission and reception procedures of Msg3. S1501, S1502, S1503, S1504, and S1506 can each be performed in the same manner as S1201, S1202, S1203, S1204, and S1206. In S1505, the terminal can transmit Msg3 to TRPy, and TRPy can receive Msg3 from the terminal.

[0192] A 4-step CBRA procedure based on a cross-PDCCH order can be performed based on one of the methods illustrated in FIGS. 11 to 15. A base station can signal to a terminal (e.g., instruct) one of the methods illustrated in FIGS. 11 to 15. The terminal can perform a 4-step CBRA procedure based on a cross-PDCCH order based on the method instructed by the base station. One of the methods illustrated in FIGS. 11 to 15 can be fixed, and the 4-step CBRA procedure based on a cross-PDCCH order can be performed based on the fixed one method. When one of the methods illustrated in FIGS. 11 to 15 is set (e.g., operated), the execution method of the 4-step CBRA procedure based on a cross-PDCCH order can be set as follows.

[0193] In a communication system where TRP #0 and TRP #1 exist, TCI state information for TRP #0 may be associated with CORESET pool #0, and TCI state information for TRP #1 may be associated with CORESET pool #1. A PDCCH (e.g., a PDCCH order) of TRP #0 may be transmitted through a CORESET associated with (e.g., belongs to) CORESET pool #0, and a PDCCH (e.g., a PDCCH order) of TRP #1 may be transmitted through a CORESET associated with (e.g., belongs to) CORESET pool #1.

[0194] Msg1 may be a signaling message transmitted to the TRP, which is the measurement target of the TA. Since the DCI that schedules the RAR message in the RA procedure is transmitted via the Type 1 CSS, the RAR message may be transmitted via the TRP associated with the CORESET pool to which the CORESET in which the Type 1 CSS is configured belongs. If the Type 1 CSS is configured in the CORESET associated with CORESET pool #0, the RAR message may be transmitted via TRP #0. Conversely, if the Type 1 CSS is configured in the CORESET associated with CORESET pool #1, the RAR message may be transmitted via TRP #1. For another example, if the Type 1 CSS is configured in the CORESETs associated with CORESET pool #0 and CORESET pool #1, the RAR message may be transmitted via TRP #0 and / or TRP #1. Since the TRP that can transmit a RAR message is determined based on the settings of the Type 1 CSS, the TRP that transmits Msg2 in the embodiments of FIGS. 11 to 15 can be determined based on the settings of the Type 1 CSS.

[0195] The UL grant for transmitting Msg3 can be transmitted to the terminal via Msg2. In other words, Msg2 transmitted to the terminal can include the UL grant for transmitting Msg3. Msg2 can include the UL grant, TCI status information, and / or TAG ID. The TCI status information and / or TAG ID can be configured to be associated with the UL grant. The UL grant, TCI status information, and / or TAG ID included in Msg2 can be used to indicate the TRP that is the transmission target of Msg3. For example, the TCI status information and / or TAG ID can be associated with the TRP that is the transmission target of Msg3. The terminal can identify the TRP that is the transmission target of Msg3 based on the UL grant, TCI status information, and / or TAG ID included in Msg2, and can transmit Msg3 to the identified TRP.

[0196] The DCI scheduling the transmission of Msg4 may be transmitted on a PDCCH, and the Msg4 may be transmitted on a PDSCH indicated by the DCI. The base station may determine a TRP for transmitting Msg4, and the TRP determined by the base station may transmit the Msg4 to the terminal.

[0197] The TRP for transmitting and receiving Msg1, Msg2, Msg3, and Msg4 can be determined based on configuration information. Based on the configuration information, one of the methods illustrated in FIGS. 11 to 15 can be used.

[0198] In the methods illustrated in FIGS. 11 to 15, TRPs capable of transmitting cross-PDCCH orders may be configured. In a communication system in which TRP #0 and TRP #1 exist, TCI state information for TRP #0 may be associated with CORESET pool #0, and TCI state information for TRP #1 may be associated with CORESET pool #1. The PDCCH (e.g., PDCCH order) of TRP #0 may be transmitted through a CORESET associated with (e.g., belongs to) CORESET pool #0, and the PDCCH (e.g., PDCCH order) of TRP #1 may be transmitted through a CORESET associated with (e.g., belongs to) CORESET pool #1.

[0199] The CORESET through which the cross-PDCCH order is transmitted may be configured to be associated with a specific CORESET pool index. For example, the cross-PDCCH order may be configured to be transmitted in the CORESET(s) associated with CORESET pool #0. Conversely, the cross-PDCCH order may be configured to be transmitted in the CORESET(s) associated with CORESET pool #1. For another example, the cross-PDCCH order may be configured to be transmitted in the CORESET(s) associated with CORESET pools #0 and #1. The base station may configure the CORESET(s) through which the cross-PDCCH order is transmitted, and may transmit information about the configuration to the terminal through signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal may expect to receive the cross-PDCCH order in the CORESET(s) configured by the base station.

[0200] In addition to the methods illustrated in FIGS. 11 to 15, a 4-step CBRA procedure based on PDCCH order can be performed as follows.

[0201] Figure 16 is a flowchart illustrating a 4-step CBRA procedure based on PDCCH order.

[0202] Referring to FIG. 16, TRPx can transmit a PDCCH order to a terminal (S1601). In other words, the base station can transmit the PDCCH order to the terminal via TRPx. The terminal can receive the PDCCH order from TRPx (S1601). In S1601, the PDCCH order can be transmitted to trigger an RA procedure for TRPx. In other words, in the embodiments of FIGS. 11 to 15, the PDCCH order of TRPx is transmitted to trigger an RA procedure for TRPy, but in the embodiment of FIG. 16, the PDCCH order of TRPx can be transmitted to trigger an RA procedure for TRPx.

[0203] The terminal can perform an RA procedure initiated by a PDCCH order with TRPx (S1602, S1603, S1604, S1605). S1602 may be a procedure for transmitting and receiving Msg1 between the terminal and TRPx. In S1602, the terminal can transmit Msg1 to TRPx, and TRPx can receive Msg1 from the terminal. S1603 may be a procedure for transmitting and receiving Msg2 between the terminal and TRPx. In S1603, TRPx can transmit Msg2 to the terminal, and the terminal can receive Msg2 from TRPx. S1604 may be a procedure for transmitting and receiving Msg3 between the terminal and TRPx. In S1604, the terminal can transmit Msg3 to TRPx, and TRPx can receive Msg3 from the terminal. S1605 may be a procedure for transmitting and receiving Msg4 between the terminal and TRPx. In S1605, the TRPx may transmit Msg4 to the terminal, and the terminal may receive Msg4 from the TRPx.

[0204] The RA procedure in FIG. 16 may be performed identically or similarly to the RA procedures illustrated in FIGS. 11 to 15. The RA procedure in FIG. 16 may be a modified RA procedure or an extended RA procedure for the RA procedures illustrated in FIGS. 11 to 15. The RA procedure in FIG. 16 may be performed based on a combination of the RA procedures illustrated in FIGS. 11 to 15.

[0205] An RA procedure with a TRP that has transmitted a PDCCH order and an RA procedure with a TRP different from the TRP that has transmitted a PDCCH order (e.g., a cross-PDCCH order) may both be possible. In this case, the PDCCH order may implicitly or explicitly include information indicating a TRP that is a target of the RA procedure triggered by the PDCCH order. TCI state information for communication with a TRP (e.g., a target of a TA procedure) may be included in the PDCCH order. The TRP that is a target of the RA procedure may be indicated by one of the above-described indication methods #1 to #6. The TRP that is a target of the RA procedure may be indicated by a modified or extended method for the above-described indication methods #1 to #6. The TRP that is a target of the RA procedure may be indicated by a combination of two or more indication methods from the above-described indication methods #1 to #6.

[0206] 2.2 Step 2 CBRA Procedure

[0207] Figures 17 and 18 are flowcharts illustrating a two-step CBRA procedure based on cross-PDCCH order.

[0208] Referring to FIGS. 17 and 18, a two-step CBRA procedure may be triggered (e.g., initiated) by a cross-PDCCH order. Messages transmitted in the two-step CBRA procedure may be referred to as MsgA and MsgB. MsgA may be a message including Msg1 and Msg3 in the four-step RA procedure. In other words, MsgA may include an RA preamble and a PUSCH. MsgB may be a message including Msg2 and Msg4 in the four-step RA procedure. The DCI scheduling the transmission of MsgB may be transmitted on the PDCCH, and MsgB may be transmitted on the PDSCH indicated by the DCI.

[0209] In the embodiment of FIG. 17, TRPx can transmit a PDCCH order to the terminal (S1701). In other words, the base station can transmit the PDCCH order to the terminal via TRPx. The terminal can receive the PDCCH order from TRPx (S1701). The terminal can perform an RA procedure initiated by the PDCCH order with TRPy (S1702, S1703). S1702 may be a procedure for transmitting and receiving MsgA between the terminal and TRPy. In S1702, the terminal can transmit MsgA to TRPy, and TRPy can receive MsgA from the terminal. S1703 may be a procedure for transmitting and receiving MsgB between the terminal and TRPy. In S1703, TRPy can transmit MsgB to the terminal, and the terminal can receive MsgB from TRPy.

[0210] In the embodiment of FIG. 18, TRPx can transmit a PDCCH order to the terminal (S1801). In other words, the base station can transmit the PDCCH order to the terminal through TRPx. The terminal can receive the PDCCH order from TRPx (S1801). The terminal can perform an RA procedure initiated by the PDCCH order (S1802, S1804). In the RA procedure, the transmission and reception procedure of MsgA can be performed between the terminal and TRPy, and the transmission and reception procedure of MsgB can be performed between the terminal and TRPx. S1802 can be a procedure for transmitting and receiving MsgA between the terminal and TRPy. In S1802, the terminal can transmit MsgA to TRPy, and TRPy can receive MsgA from the terminal. TRPy, which has received MsgA, can generate information necessary for generating MsgB. The information required to generate MsgB may include TA information measured by TRPy. TRPy may determine TA based on MsgA received from the terminal and generate TA information including the determined TA. The TA may be determined by the base station to which TRPy is connected. The information required to generate MsgB may include the RNTI determined by TRPy. The RNTI may be determined by the base station to which TRPy is connected.

[0211] Information required for generating MsgB can be defined as RAR configuration information. In S1803, TRPy can transmit RAR configuration information to TRPx, and TRPx can receive RAR configuration information from TRPy. S1803 can be a sharing step of RAR configuration information (e.g., TA information). RAR configuration information can include at least one of TA information, information required for determining TA, RNTI for MsgB transmission, or information required for determining RNTI for MsgB transmission. S1803 can be performed identically or similarly to S1003 illustrated in FIG. 10. In S1804, TRPx can transmit MsgB to a terminal, and the terminal can receive MsgB from TRPx.

[0212] A two-step CBRA procedure based on a cross-PDCCH order can be performed based on one of the methods illustrated in FIGS. 17 and 18 . The base station can signal to a terminal to configure (e.g., instruct) one of the methods illustrated in FIGS. 17 and 18 . The terminal can perform a two-step CBRA procedure based on the method instructed by the base station. One of the methods illustrated in FIGS. 17 and 18 can be fixed, and the two-step CBRA procedure based on a cross-PDCCH order can be performed based on the fixed one method. When one of the methods illustrated in FIGS. 17 and 18 is configured (e.g., operated), the method for performing the two-step CBRA procedure based on the cross-PDCCH order can be configured as follows.

[0213] In a communication system where TRP #0 and TRP #1 exist, TCI state information for TRP #0 may be associated with CORESET pool #0, and TCI state information for TRP #1 may be associated with CORESET pool #1. A PDCCH (e.g., a PDCCH order) of TRP #0 may be transmitted through a CORESET associated with (e.g., belongs to) CORESET pool #0, and a PDCCH (e.g., a PDCCH order) of TRP #1 may be transmitted through a CORESET associated with (e.g., belongs to) CORESET pool #1.

[0214] MsgA may be a signaling message transmitted to a TRP that is a measurement target of a TA. Since the DCI that schedules MsgB in the RA procedure is transmitted via a Type 1 CSS, the MsgB may be transmitted via a TRP associated with a CORESET pool to which the CORESET to which the Type 1 CSS is configured belongs. If the Type 1 CSS is configured in a CORESET associated with CORESET pool #0, MsgB may be transmitted via TRP #0. Conversely, if the Type 1 CSS is configured in a CORESET associated with CORESET pool #1, MsgB may be transmitted via TRP #1. For another example, if the Type 1 CSS is configured in CORESETs associated with CORESET pool #0 and CORESET pool #1, MsgB may be transmitted via TRP #0 and / or TRP #1. Since the TRP that can transmit MsgB is determined based on the settings of Type 1 CSS, in the embodiments of FIGS. 17 and 18, the TRP that transmits MsgB can be determined based on the settings of Type 1 CSS.

[0215] In the methods illustrated in FIGS. 17 and 18, TRPs capable of transmitting cross-PDCCH orders can be configured. In a communication system where TRP #0 and TRP #1 exist, TCI state information for TRP #0 can be associated with CORESET pool #0, and TCI state information for TRP #1 can be associated with CORESET pool #1. The PDCCH (e.g., PDCCH order) of TRP #0 can be transmitted through a CORESET associated with (e.g., belongs to) CORESET pool #0, and the PDCCH (e.g., PDCCH order) of TRP #1 can be transmitted through a CORESET associated with (e.g., belongs to) CORESET pool #1.

[0216] The CORESET through which the cross-PDCCH order is transmitted may be configured to be associated with a specific CORESET pool index. For example, the cross-PDCCH order may be configured to be transmitted in the CORESET(s) associated with CORESET pool #0. Conversely, the cross-PDCCH order may be configured to be transmitted in the CORESET(s) associated with CORESET pool #1. For another example, the cross-PDCCH order may be configured to be transmitted in the CORESET(s) associated with CORESET pools #0 and #1. The base station may configure the CORESET(s) through which the cross-PDCCH order is transmitted, and may transmit information about the configuration to the terminal through signaling (e.g., SI signaling, RRC signaling, MAC CE signaling, and / or PHY signaling). The terminal may expect to receive the cross-PDCCH order in the CORESET(s) configured by the base station.

[0217] In addition to the methods illustrated in FIGS. 17 and 18, a two-step CBRA procedure based on PDCCH order can be performed as follows.

[0218] Figure 19 is a flowchart illustrating a two-step CBRA procedure based on PDCCH order.

[0219] Referring to FIG. 19, TRPx can transmit a PDCCH order to a terminal (S1901). In other words, the base station can transmit a PDCCH order to the terminal via TRPx. The terminal can receive the PDCCH order from TRPx (S1901). In S1901, the PDCCH order can be transmitted to trigger an RA procedure for TRPx. In other words, in the embodiments of FIGS. 17 and 18, the PDCCH order of TRPx is transmitted to trigger an RA procedure for TRPy, but in the embodiment of FIG. 19, the PDCCH order of TRPx can be transmitted to trigger an RA procedure for TRPx.

[0220] The terminal can perform an RA procedure initiated by a PDCCH order with TRPx (S1902, S1903). S1902 may be a procedure for transmitting and receiving MsgA between the terminal and TRPx. In S1902, the terminal can transmit MsgA to TRPx, and TRPx can receive MsgA from the terminal. S1903 may be a procedure for transmitting and receiving MsgB between the terminal and TRPx. In S1903, TRPx can transmit MsgB to the terminal, and the terminal can receive MsgB from TRPx.

[0221] The RA procedure in Fig. 19 may be performed identically or similarly to the RA procedures illustrated in Figs. 17 and 18. The RA procedure in Fig. 19 may be a modified RA procedure or an extended RA procedure for the RA procedures illustrated in Figs. 17 and 18. The RA procedure in Fig. 19 may be performed based on a combination of the RA procedures illustrated in Figs. 17 and 18.

[0222] An RA procedure with a TRP that has transmitted a PDCCH order and an RA procedure with a TRP different from the TRP that has transmitted a PDCCH order (e.g., a cross-PDCCH order) may both be possible. In this case, the PDCCH order may implicitly or explicitly include information indicating a TRP that is a target of the RA procedure triggered by the PDCCH order. TCI state information for communication with a TRP (e.g., a target of a TA procedure) may be included in the PDCCH order. The TRP that is a target of the RA procedure may be indicated by one of the above-described indication methods #1 to #6. The TRP that is a target of the RA procedure may be indicated by a modified or extended method for the above-described indication methods #1 to #6. The TRP that is a target of the RA procedure may be indicated by a combination of two or more indication methods from the above-described indication methods #1 to #6.

[0223] The operations of the method according to the present disclosure can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes any type of recording device that stores information readable by a computer system. Furthermore, a computer-readable recording medium can be distributed across network-connected computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0224] Additionally, the computer-readable recording medium may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. The program instructions may include not only machine language codes produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

[0225] While some aspects of the present disclosure have been described in the context of a device, they may also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described as a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, at least one or more of the most significant method steps may be performed by such a device.

[0226] A programmable logic device (e.g., a field-programmable gate array) may be used to perform some or all of the functions of the methods described in the present disclosure. The field-programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described in the present disclosure. In general, the methods are preferably performed by some hardware device.

[0227] Although the present disclosure has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present disclosure without departing from the spirit and scope of the present disclosure as set forth in the claims below.

Claims

1. As a method of UE (user equipment), A step of receiving a cross-PDCCH (physical downlink control channel) order from a first TRP (transmission and reception point); A step of confirming a second TRP, which is a target of performing a random access (RA) procedure, based on the first indication information included in the above cross-PDCCH order; and A step of transmitting a message including an RA preamble to the second TRP, The above first TRP and the above second TRP are different TRPs. UE's method.

2. In claim 1, The above first instruction information indicates a TAG (timing advance group) ID (identifier), and the TAG ID is set to be associated with a TCI (transmission configuration indicator) state. UE's method.

3. In claim 1, The above first instruction information indicates the TCI status for the above second TRP. UE's method.

4. In claim 1, The above first instruction information indicates a dedicated preamble for the RA procedure, and the dedicated preamble group to which the dedicated preamble belongs is set to be associated with a CORESET (control resource pool) pool, and the CORESET pool is set to be associated with a TCI state. UE's method.

5. In claim 1, The above first instruction information indicates a RO (RACH (random access channel) occasion) for transmission of the message, and the RO group to which the RO belongs is set to be associated with a CORESET pool, and the CORESET pool is set to be associated with a TCI state. UE's method.

6. In claim 1, The above first instruction information indicates a cell ID (identifier), and the second TRP belongs to a cell indicated by the cell ID. UE's method.

7. In claim 1, The above message including the above RA preamble is Msg1 in the 4-step RA procedure or MsgA in the 2-step RA procedure. UE's method.

8. In claim 1, Further comprising a step of receiving a RAR (random access response) message in response to the above message from the first TRP or the second TRP, The RAR message includes TA (timing advance) information for the second TRP. UE's method.

9. In claim 8, The UE expects to receive the RAR message from one of the TRPs associated with the CORESET pool to which the CORESET with type 1 CSS (common search space) set belongs, either the first TRP or the second TRP. UE's method.

10. In claim 8, The above RAR message further includes a UL (uplink) grant and second indication information indicating a transmission target of Msg3, and the Msg3 is transmitted to one TRP among the first TRP or the second TRP, which is determined based on the second indication information. UE's method.

11. As a method of base station, A step of generating a cross-PDCCH (physical downlink control channel) order indicating a second TRP (transmission and reception point) that is a target of performing an RA (random access) procedure; and A step of transmitting the above cross-PDCCH order to a UE (user equipment) through a first TRP, In the RA procedure triggered by the cross-PDCCH order, a message including an RA preamble is transmitted from the UE to the second TRP, wherein the first TRP and the second TRP are different TRPs connected to the base station. Method of base station.

12. In claim 11, The above first instruction information indicates a TAG (timing advance group) ID (identifier), and the TAG ID is set to be associated with a TCI (transmission configuration indicator) state. Method of base station.

13. In claim 11, The above first instruction information indicates the TCI status for the above second TRP. Method of base station.

14. In claim 11, The above first instruction information indicates a dedicated preamble for the RA procedure, and the dedicated preamble group to which the dedicated preamble belongs is set to be associated with a CORESET (control resource pool) pool, and the CORESET pool is set to be associated with a TCI state. Method of base station.

15. In claim 11, The above first instruction information indicates a RO (RACH (random access channel) occasion) for transmission of the message, and the RO group to which the RO belongs is set to be associated with a CORESET pool, and the CORESET pool is set to be associated with a TCI state. Method of base station.

16. In claim 11, The above first instruction information indicates a cell ID (identifier), and the second TRP belongs to a cell indicated by the cell ID. Method of base station.

17. In claim 11, The above message including the above RA preamble is Msg1 in the 4-step RA procedure or MsgA in the 2-step RA procedure. Method of base station.

18. As a UE (user equipment), Contains at least one processor, At least one processor of the UE, Receive a cross-PDCCH (physical downlink control channel) order from a first TRP (transmission and reception point); Identifying a second TRP that is a target of performing a random access (RA) procedure based on the first indication information included in the above cross-PDCCH order; and Causes the second TRP to transmit a message including an RA preamble, The above first TRP and the above second TRP are different TRPs. UE.

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

20. In claim 18, At least one processor of the UE, Further causing a RAR (random access response) message in response to the above message to be received from the first TRP or the second TRP, The above RAR message is received from one TRP associated with a CORESET pool to which a CORESET with a type 1 CSS (common search space) set belongs, either among the first TRP or the second TRP. UE.

Images