Method and apparatus for resource allocation at multiple transmission and reception points in wireless communication system

Abstract

A method of a UE according to an embodiment of the present invention may comprise the steps of: transmitting a preamble signal to each of two or more TRPs; receiving first information including an RP value obtained by measuring a preamble signal in each of the two or more TRPs and a propagation delay time of the preamble signal from each of the two or more TRPs; determining, based on first information received from each of the two or more TRPs, a first communication group including TRPs capable of communicating; selecting a reference TRP in the first communication group; and transmitting, to the reference TRP, first information received from one or more TRPs other than the reference TRP among the TRPs capable of communication.

Description

Technical Field

[0001] The present invention relates to an enhanced communication technology, and more particularly, to a technique for resource allocation in a multiple transmission and reception points (MTRPs) environment. Background Art

[0002] Communication networks (e.g., 5G communication networks or 6G communication networks) are being developed to provide enhanced communication services compared to existing communication networks (e.g., long term evolution (LTE), LTE-Advanced (LTE-A), etc.). A 5G communication network (e.g., a New Radio (NR) communication network) can support frequency bands below 6 GHz and above 6 GHz. In other words, a 5G communication network can support Frequency Range 1 (FR1) bands and / or FR2 bands. Compared to an LTE communication network, a 5G communication network can support various communication services and scenarios. For example, the usage scenarios of a 5G communication network can include enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communication (URLLC), massive Machine Type Communication (mMTC), etc.

[0003] Compared to a 5G communication network, a 6G communication network can support a wide variety of communication services and scenarios. A 6G communication network can meet the requirements of super performance, super bandwidth, super space, super precision, super intelligence, and / or super reliability. A 6G communication network can support multiple wide frequency bands and can be applied to various usage scenarios, such as terrestrial communication, non-terrestrial communication, sidelink communication, etc.

[0004] On the other hand, in 5G NR, the Multiple Transmission and Reception Point (MTRP) technology refers to the technology in which a base station (e.g., gNB) communicates with a terminal using multiple physically separated TRPs. The MTRP technology can solve problems such as the degradation of the quality of service (QoS) of terminals located at the cell edge far from the base station, and the inter-cell interference caused by signals from base stations in different cells. In addition, the MTRP technology can provide additional communication paths for terminals located in non-line-of-sight (NLOS) paths (e.g., those in the millimeter wave band).

[0005] In the MTRP technology, TRPs can be deployed at various positions within the coverage area of a specific base station. In other words, multiple TRPs can be installed at different positions within a single base station. Therefore, a single terminal can communicate with two or more TRPs. In this case, a method for selecting TRPs and allocating resources to the selected TRPs is required. Summary of the Invention

[0006] Technical Problem

[0007] The present invention is dedicated to providing a method and apparatus for TRP selection and resource allocation in an MTRP environment of a communication system.

[0008] Technical Solution

[0009] A method for a user equipment (UE) for achieving the above object according to a first exemplary embodiment of the present invention may include: transmitting a preamble signal to each of two or more transmission and reception points (TRPs); receiving first information from each of the two or more TRPs, the first information including the propagation delay of the preamble signal and the received power (RP) value measured at each of the two or more TRPs; determining a first communication group including TRPs capable of communication based on the first information received from each of the two or more TRPs; selecting a reference TRP within the first communication group; transmitting the first information received from one or more TRPs other than the reference TRP among the TRPs capable of communication included in the first communication group to the reference TRP; and receiving a timing advance (TA) value to be used for uplink communication with the TRPs capable of communication included in the first communication group from the reference TRP.

[0010] The first information received from each of the two or more TRPs may further include an identifier (ID) of the TRP that transmitted the first information.

[0011] The method may further include: sending second information to all TRPs that have received the first information, the second information including information about a reference TRP and one or more TRPs included in a first communication group.

[0012] Each of the communicable TRPs included in the first communication group may be a TRP having a propagation delay less than a preset threshold.

[0013] The preset threshold may be determined based on the UE's capability information.

[0014] The reference TRP may be the TRP having the highest RP value among the communicable TRPs within the first communication group.

[0015] Each of the communicable TRPs included in the first communication group may be a TRP having an RP value equal to or greater than the preset threshold.

[0016] The reference TRP may be the TRP having the minimum propagation delay among the communicable TRPs within the first communication group.

[0017] The method may further include: receiving, from the reference TRP, a command and third information indicating to send the third information to at least one TRP included in the first communication group; and sending the third information to at least one TRP included in the first communication group, wherein the third information includes at least one of a TRP identifier, a parameter set, a subcarrier spacing (SCS), or a cyclic prefix (CP).

[0018] A method of a first base station for achieving the above object according to an exemplary embodiment of the present invention may include: receiving a preamble signal from a user equipment (UE) via a transmit and receive point (TRP) connected to the first base station; measuring a propagation delay and a received power (RP) of the preamble signal; sending, via the TRP, first information including the measured propagation delay and RP to the UE; receiving second information including information about at least one other TRP and information about propagation delay and RP sent by the at least one other TRP to the UE; determining a timing advance (TA) value and third information to be used for communicating with the UE based on the first information and the second information corresponding to the at least one other TRP; and sending the TA value to the UE via the TRP, wherein the third information includes at least one of a parameter set, a subcarrier spacing (SCS), or a cyclic prefix (CP) to be used by at least one other TRP for communicating with the UE.

[0019] The method may further include: receiving, from the UE, information about a first communication group including at least one other TRP capable of communicating with the UE.

[0020] The method may further include: sending third information to a TRP included in a first communication group or to a second base station connected to the TRP included in the first communication group.

[0021] The method may further include: sending third information and first instruction information to a UE, where the first instruction information is information indicating to send the third information to a TRP included in the first communication group.

[0022] A user equipment (UE) for achieving the above object according to an exemplary embodiment of the present invention may include at least one processor, where the at least one processor may cause the UE to perform: sending a preamble signal to each of two or more transmit and receive points (TRPs); receiving first information from each of the two or more TRPs, the first information including a propagation delay of the preamble signal and a received power (RP) value measured at each of the two or more TRPs; determining a first communication group including TRPs capable of communication based on the first information received from each of the two or more TRPs; selecting a reference TRP within the first communication group; sending the first information received from one or more TRPs other than the reference TRP among the TRPs capable of communication included in the first communication group to the reference TRP; and receiving a timing advance (TA) value to be used for uplink communication with the TRPs capable of communication included in the first communication group from the reference TRP.

[0023] The first information received from each of the two or more TRPs may further include an identifier (ID) of the TRP that sent the first information.

[0024] The at least one processor may further cause the UE to perform: sending second information to all the TRPs that have received the first information, the second information including information about the reference TRP and one or more TRPs included in the first communication group.

[0025] Each of the TRPs capable of communication included in the first communication group may be a TRP having a propagation delay less than a preset threshold.

[0026] The preset threshold may be determined based on the capability information of the UE, and the reference TRP may be the TRP having the highest RP value among the TRPs capable of communication within the first communication group.

[0027] Each of the TRPs capable of communication included in the first communication group may be a TRP having an RP value equal to or greater than the preset threshold, and the reference TRP may be the TRP having the minimum propagation delay among the TRPs capable of communication within the first communication group.

[0028] At least one processor may cause the UE to perform: receiving, from a reference TRP, a command indicating to send third information to at least one TRP included in a first communication group and the third information; and sending the third information to at least one TRP included in the first communication group, where the third information includes at least one of a TRP identifier, a parameter set, a subcarrier spacing (SCS), or a cyclic prefix (CP).

[0029] Advantageous Effects

[0030] According to the present invention, in an MTRP environment, there is an advantage of being able to perform uplink transmission to multiple TRPs using a single timing advance (TA) value without inter-symbol interference (ISI). Additionally, in an MTRP environment, communication efficiency can be improved by allowing the parameter set, subcarrier spacing (SCS), and cyclic prefix (CP) of each TRP to be determined based on the TA value at the reference TRP and / or the base station associated with the reference TRP. Furthermore, in the case where a TRP does not have a backhaul connection, there is an advantage of being able to send such information to a communicating TRP other than the reference TRP via the UE as a medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a conceptual diagram showing a first exemplary embodiment of a communication system.

[0032] Figure 2 is a block diagram showing a first exemplary embodiment of a communication node constituting a communication system.

[0033] Figure 3 is a block diagram showing a first exemplary embodiment of a communication node performing communication.

[0034] Figure 4a is a block diagram showing a first exemplary embodiment of a transmission path.

[0035] Figure 4b is a block diagram showing a first exemplary embodiment of a reception path.

[0036] Figure 5 is a conceptual diagram showing a first exemplary embodiment of a system frame in a communication system.

[0037] Figure 6 is a conceptual diagram showing a first exemplary embodiment of a subframe in a communication system.

[0038] Figure 7 is a conceptual diagram showing a first exemplary embodiment of a time slot in a communication system.

[0039] Figure 8 is a conceptual diagram showing a first exemplary embodiment of a time-frequency resource in a communication system.

[0040] Figure 9a is a conceptual diagram showing downlink reception timing and uplink transmission timing based on a reference TRP and TA configuration according to the current NR technical specification in a 5G NR MTRP environment.

[0041] Figure 9b is a conceptual diagram showing uplink transmission timing and expected uplink transmission timing based on a reference TRP and TA configuration according to the current NR technical specification in a 5G NR MTRP environment.

[0042] Figure 10 is a sequence diagram showing the process of a UE sending a PRACH preamble to multiple TRPs.

[0043] Figure 11 is a sequence diagram showing the situation where multiple TRPs provide propagation delay and RSRP values to a UE.

[0044] Figure 12 is a sequence diagram showing the process of a UE determining a communication TRP and a reference TRP.

[0045] Figure 13 is a sequence diagram showing the situation where a UE sends information about the determined communication TRP and reference TRP to all TRPs to which the PRACH preamble has been sent.

[0046] Figure 14 is a sequence diagram showing the situation where a UE sends the identifier and propagation delay value of a communication TRP other than the reference TRP to the reference TRP.

[0047] Figure 15 is a sequence diagram showing the situation where a reference TRP determines information about resources to be used between the reference TRP and the UE and information about resources to be used between communication TRPs other than the reference TRP and the UE.

[0048] Figure 16 is a sequence diagram showing the situation where a reference TRP sends information about allocated resources to other communication TRPs and the UE.

[0049] Figure 17 is a timing diagram showing the situation where a reference TRP sends, via the UE, information about resources to be used by a communication TRP for communicating with the UE to other communication TRPs.

[0050] Figure 18 is a conceptual diagram showing the operation flow of the overall combination based on an exemplary embodiment of the present invention.

[0051] Figure 19It is a sequence diagram showing the situation of using all exemplary embodiments to determine resources for communicating with a UE in the case where there is a backhaul between TRPs.

[0052] Figure 20 It is a sequence diagram showing the situation of using all exemplary embodiments to determine resources for communicating with a UE in an environment where there is no backhaul between TRPs. Detailed Description

[0053] Since the present invention can be modified in various ways and can have various forms, specific exemplary embodiments will be shown in the drawings and described in detail in the detailed description. However, it should be understood that it is not intended to limit the present invention to the specific exemplary embodiments, but on the contrary, the present invention covers all modifications and alternative forms falling within the spirit and scope of the present invention.

[0054] Relational terms such as first, second, etc. may be used to describe various elements, but these elements should not be limited by the terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and the second component may be similarly named the first component. The term "and / or" means any one or combination of a plurality of related and described matters.

[0055] In the present invention, "at least one of A and B" may refer to "at least one of A or B" or "at least one of a combination of one or more of A and B". In addition, "one or more of A and B" may refer to "one or more of A or B" or "one or more of a combination of one or more of A and B".

[0056] In the present invention, "(re)transmission" may refer to "transmission", "retransmission" or "transmission and retransmission", "(re)configuration" may refer to "configuration", "reconfiguration" or "configuration and reconfiguration", "(re)connection" may refer to "connection", "reconnection" or "connection and reconnection", and "(re)access" may refer to "access", "reaccess" or "access and reaccess".

[0057] When it is mentioned that a certain component is "coupled" or "connected" to another component, it should be understood that the certain component is directly "coupled" or "connected" to the other component, or additional components may be provided between them. On the contrary, when it is mentioned that a certain component is "directly coupled" or "directly connected" to another component, it should be understood that no additional components are provided between them.

[0058] The terms used in the present invention are only for describing specific exemplary embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In the present invention, terms such as "comprising" or "having" are intended to indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification. However, it should be understood that these terms do not preclude the presence or addition of one or more features, numbers, steps, operations, components, parts, or combinations thereof.

[0059] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms commonly used in a dictionary and already in the dictionary should be interpreted as having a meaning that matches the contextual meaning in the art. In this specification, terms are not necessarily to be interpreted as having a formal meaning unless explicitly defined.

[0060] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing the present invention, for the sake of a comprehensive understanding of the present invention, the same reference numerals refer to the same elements throughout the description of the drawings, and repeated descriptions thereof will be omitted. Operations according to the explicitly described exemplary embodiments of the present invention, combinations of exemplary embodiments, extensions of exemplary embodiments, and / or variant forms of exemplary embodiments can be performed. Some operations may be omitted, and the order of operations may be changed.

[0061] Even when describing a method (e.g., transmission or reception of a signal) performed at a first communication node in a communication node in an exemplary embodiment, the corresponding second communication node may perform a method corresponding to the method performed at the first communication node (e.g., reception or transmission of a signal). That is, when describing the operation of a user equipment (UE), the corresponding base station may perform an operation corresponding to the operation of the UE. Conversely, when describing the operation of a base station, the corresponding UE may perform an operation corresponding to the operation of the base station.

[0062] A base station can be referred to by various terms, such as Node B, evolved Node B, next-generation Node B (gNodeB), gNB, device, apparatus, node, communication node, base transceiver station (BTS), radio remote head (RRH), transmission reception point (TRP), radio unit (RU), roadside unit (RSU), radio transceiver, access point, access node, etc. A user equipment (UE) can be referred to by various terms, such as terminal, device, apparatus, node, communication node, end node, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, on-board unit (OBU), etc.

[0063] In the present invention, the signaling can be one of higher-layer signaling, MAC signaling, and physical (PHY) signaling, or a combination of two or more of them. A message for higher-layer signaling can be called a "higher-layer message" or a "higher-layer signaling message". A message for MAC signaling can be called a "MAC message" or a "MAC signaling message". A message for PHY signaling can be called a "PHY message" or a "PHY signaling message". Higher-layer signaling can refer to the operation of sending and receiving system information (e.g., master information block (MIB), system information block (SIB)) and / or RRC messages. MAC signaling can refer to the operation of sending and receiving MAC control elements (CE). PHY signaling can refer to the operation of sending and receiving control information (e.g., downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI)).

[0064] In the present invention, the "configuration of an operation (e.g., a transmission operation)" can refer to the configuration information (e.g., information element, parameter) required for the operation and / or the signaling indicating the information for performing the operation. The "configuration of an information element (e.g., a parameter)" can refer to the signaling of the information element. In the present invention, "signal and / or channel" can refer to a signal, a channel, or both a signal and a channel, and "signal" can be used to mean "signal and / or channel".

[0065] The communication network of the exemplary implementation is not limited to the communication network described below, and the exemplary implementation can be applied to various communication networks (e.g., 4G communication network, 5G communication network, and / or 6G communication network). Herein, the term "communication network" can be used interchangeably with the term "communication system".

[0066] Figure 1 It is a conceptual diagram showing a first exemplary implementation of a communication system.

[0067] As Figure 1 shown, 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, and 130-6. Additionally, the communication system 100 may further include: a core network (e.g., serving gateway (S-GW), packet data network (PDN) gateway (P-GW), mobility management entity (MME)). When the communication system 100 is 5G communication (e.g., NR system), the core network may include access and mobility management function (AMF), user plane function (UPF), session management function (SMF), etc.

[0068] Multiple communication nodes 110 to 130 may support communication protocols specified in the 3rd generation partnership project (3GPP) standards (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.). The multiple communication nodes 110 to 130 may support the following technologies: code division multiple access (CDMA) technology, wideband CDMA (WCDMA) technology, time division multiple access (TDMA) technology, frequency division multiple access (FDMA) technology, orthogonal frequency division multiplexing (OFDM) technology, filtered OFDM technology, cyclic prefix OFDM (CP-OFDM) technology, discrete Fourier transform spread OFDM (DFT-s-OFDM) technology, orthogonal frequency division multiple access (OFDMA) technology, single carrier FDMA (SC-FDMA) technology, non-orthogonal multiple access (NOMA) technology, generalized frequency division multiplexing (GFDM) technology, filter bank multi-carrier (FBMC) technology, universal filtered multi-carrier (UFMC) technology, space division multiple access (SDMA) technology, etc. Each of the multiple communication nodes may have the following structure.

[0069] Figure 2 It is a block diagram showing a first exemplary embodiment of a communication node constituting a communication system.

[0070] As Figure 2As shown, the communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 connected to a network for performing communication. 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 can communicate with each other when connected via a bus 270.

[0071] The processor 210 may execute a program 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 on which a method according to an embodiment of the present invention is executed. Each of the memory 220 and the storage device 260 may be constituted by at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may include at least one of a read-only memory (ROM) and a random access memory (RAM).

[0072] Referring again to Figure 1 , the communication system 100 may include a plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and a plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. The communication system 100 including the base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and the terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 may be referred to as an "access network". Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell, and 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 belong to the cell coverage area of the first base station 110-1. In addition, the second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the cell coverage area of the second base station 110-2. In addition, the fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong to the cell coverage area of the third base station 110-3. In addition, the first terminal 130-1 may belong to the cell coverage area of the fourth base station 120-1, and the sixth terminal 130-6 may belong to the cell coverage area of the fifth base station 120-2.

[0073] Here, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can refer to a Node-B, evolved Node-B (eNB), gNB, advanced base station (ABS), high-reliability base station (HR-BS), base transceiver station (BTS), radio base station, radio transceiver, access point, access node, radio access station (RAS), mobile multihop relay-base station (MMR-BS), relay station (RS), advanced relay station (ARS), high-reliability relay station (HR-RS), home NodeB (HNB), home eNodeB (HeNB), road side unit (RSU), radio remote head (RRH), transmission point (TP), transmission and reception point (TRP), etc.

[0074] Each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can refer to 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.

[0075] On the other hand, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can operate in the same frequency band or different frequency bands. The plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be connected to each other via ideal backhaul or non-ideal backhaul and exchange information with each other via ideal or non-ideal backhaul. In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be connected to the core network via ideal or non-ideal backhaul. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can send the signals received from the core network to the corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6, and send the signals received from the corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 to the core network.

[0076] In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may support multiple-input multiple-output (MIMO) transmission (e.g., single-user MIMO (SU-MIMO), multi-user MIMO (MU-MIMO), massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, sidelink communication (e.g., device-to-device (D2D) communication, proximity service (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 may perform operations corresponding to the following: operations of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and operations supported by the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2. For example, the second base station 110-2 may send a signal to the fourth terminal 130-4 in an SU-MIMO manner, and the fourth terminal 130-4 may receive the signal from the second base station 110-2 in an SU-MIMO manner. Alternatively, the second base station 110-2 may send a signal to the fourth terminal 130-4 and the fifth terminal 130-5 in an MU-MIMO manner, and the fourth terminal 130-4 and the fifth terminal 130-5 may receive the signal from the second base station 110-2 in an MU-MIMO manner.

[0077] The first base station 110-1, the second base station 110-2, and the third base station 110-3 may send a signal to the fourth terminal 130-4 in a CoMP transmission manner, and the fourth terminal 130-4 may receive the signal from the first base station 110-1, the second base station 110-2, and the third base station 110-3 in a CoMP manner. In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may exchange signals with the corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 belonging to its cell coverage area in a CA manner. Each of the base stations 110-1, 110-2, and 110-3 may control the sidelink communication between the fourth terminal 130-4 and the fifth terminal 130-5, so that the fourth terminal 130-4 and the fifth terminal 130-5 may perform sidelink communication under the control of the second base station 110-2 and the third base station 110-3, respectively.

[0078] On the other hand, a communication node that performs communication in a communication network may be configured as follows. Figure 3 The illustrated communication node may be Figure 2 a specific exemplary embodiment of the illustrated communication node.

[0079] Figure 3 is a block diagram showing a first exemplary embodiment of a communication node that performs communication.

[0080] As Figure 3 shown, 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 send a signal to the second communication node 300b. A 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 a 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).

[0081] The transmission processor 311 may generate data symbols by performing processing operations on the data (e.g., encoding operations, symbol mapping operations, etc.). The transmission processor 311 may generate control symbols by performing processing operations on the control information (e.g., encoding operations, symbol mapping operations, etc.). In addition, the transmission processor 311 may generate synchronization / reference symbols for synchronization signals and / or reference signals.

[0082] A Tx MIMO processor 312 may perform spatial processing operations (e.g., precoding operations) on the data symbols, control symbols, and / or synchronization / reference symbols. The output of the Tx MIMO processor 312 (e.g., a symbol stream) may be provided to a modulator (MOD) included in transceivers 313a to 313t. The modulator may generate modulated symbols by performing processing operations on the symbol stream, and may generate a signal by performing additional processing operations on the modulated symbols (e.g., analog conversion operations, amplification operations, filtering operations, upconversion operations, etc.). The signals generated by the modulators of the transceivers 313a to 313t may be transmitted through antennas 314a to 314t.

[0083] The signal transmitted by the first communication node 300a can be received at antennas 364a to 364r of the second communication node 300b. The signals received at antennas 364a to 364r can be provided to a demodulator (DEMOD) included in transceivers 363a to 363r. The demodulator (DEMOD) can obtain samples by performing processing operations on the signals (e.g., filtering operations, amplification operations, down-conversion operations, digital conversion operations, etc.). The demodulator can perform additional processing operations on the samples to obtain symbols. The MIMO detector 362 can perform MIMO detection operations on the symbols. The receive processor 361 can perform processing operations on the symbols (e.g., deinterleaving operations, decoding operations, etc.). The output of the receive processor 361 can be provided to the data sink 360 and the controller 366. For example, data can be provided to the data sink 360, and control information can be provided to the controller 366.

[0084] On the other hand, the second communication node 300b can transmit a signal to the first communication node 300a. The transmit processor 368 included in the second communication node 300b can receive data (e.g., data units) from the data source 367 and perform processing operations on the data to generate data symbols. The transmit processor 368 can receive control information from the controller 366 and perform processing operations on the control information to generate control symbols. In addition, the transmit processor 368 can generate reference symbols by performing processing operations on reference signals.

[0085] The Tx MIMO processor 369 can perform spatial processing operations (e.g., precoding operations) on the data symbols, control symbols, and / or reference symbols. The output of the Tx MIMO processor 369 (e.g., symbol stream) can be provided to a modulator (MOD) included in transceivers 363a to 363t. The modulator can generate modulated symbols by performing processing operations on the symbol stream and can generate signals by performing additional processing operations on the modulated symbols (e.g., analog conversion operations, amplification operations, filtering operations, up-conversion operations). The signals generated by the modulators of transceivers 363a to 363t can be transmitted through antennas 364a to 364t.

[0086] The signal transmitted by the second communication node 300b can be received at the antennas 314a to 314r of the first communication node 300a. The signals received at the antennas 314a to 314r can be provided to the demodulators (DEMOD) included in the transceivers 313a to 313r. The demodulator can obtain samples by performing processing operations on the signals (e.g., filtering operation, amplification operation, down-conversion operation, digital conversion operation). The demodulator can perform additional processing operations on the samples to obtain symbols. The MIMO detector 320 can perform MIMO detection operations on the symbols. The receive processor 319 can perform processing operations on the symbols (e.g., deinterleaving operation, decoding operation, etc.). The output of the receive processor 319 can be provided to the data sink 318 and the controller 316. For example, data can be provided to the data sink 318, and control information can be provided to the controller 316.

[0087] The memories 315 and 365 can store data, control information, and / or program code. The scheduler 317 can perform scheduling operations for communication. Figure 3 The illustrated processors 311, 312, 319, 361, 368, and 369, and the controllers 316 and 366 can be Figure 2 the illustrated processor 210, and can be used to execute the methods described in the present invention.

[0088] Figure 4a is a block diagram showing a first exemplary embodiment of the transmission path, Figure 4b is a block diagram showing a first exemplary embodiment of the reception path.

[0089] As Figure 4a and Figure 4bAs shown, a transmission path 410 can be implemented in a communication node that transmits a signal, and a reception path 420 can be implemented in a communication node that receives a signal. The transmission path 410 can include: a channel coding and modulation block 411, a serial-to-parallel (S-to-P) block 512, an N-point inverse fast Fourier transform (N-point IFFT) block 413, a parallel-to-serial (P-to-S) block 414, a cyclic prefix (CP) addition block 415, and an up-converter (UC) 416. The reception path 420 can include a down-converter (DC) 421, a CP removal block 422, an S-to-P block 423, an N-point FFT block 424, a P-to-S block 425, and a channel decoding and demodulation block 426. Here, N can be a natural number.

[0090] In the transmission path 410, information bits can be input to the channel coding and modulation block 411. The channel coding and modulation block 411 can perform encoding / decoding operations on the information bits (e.g., low-density parity check (LDPC) encoding / decoding operations, polar encoding / decoding operations, etc.) and modulation operations (e.g., Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (QAM), etc.). The output of the channel coding and modulation block 411 can be a sequence of modulated symbols.

[0091] The S-to-P block 412 can convert the frequency-domain modulated symbols into a parallel symbol stream to generate N parallel symbol streams. N can be the IFFT size or the FFT size. The N-point IFFT block 413 can generate a time-domain signal by performing an IFFT operation on the N parallel symbol streams. The P-to-S block 414 can convert the output of the N-point IFFT block 413 (e.g., the parallel signal) into a serial signal to generate a serial signal.

[0092] The CP addition block 415 can insert a CP into the signal. The UC 416 can up-convert the frequency of the output of the CP addition block 415 to a radio frequency (RF) frequency. In addition, the output of the CP addition block 415 can be filtered in the baseband before up-conversion.

[0093] The signal transmitted from the transmission path 410 can be input to the reception path 420. The operations in the reception path 420 can be the opposite operations of those in the transmission path 410. The DC 421 can down-convert the frequency of the received signal to the baseband frequency. The CP removal block 422 can remove the CP from the signal. The output of the CP removal block 422 can be a serial signal. The S-to-P block 423 can convert the serial signal into a parallel signal. The N-point FFT block 424 can generate N parallel signals by performing the FFT algorithm. The P-to-S block 425 can convert the parallel signal into a modulated symbol sequence. The channel decoding and demodulation block 426 can perform the demodulation operation on the modulated symbols and can recover the data by performing the decoding operation on the result of the demodulation operation.

[0094] In Figure 4a and Figure 4b the discrete Fourier transform (DFT) and the inverse DFT (IDFT) can be used instead of the FFT and the IFFT. Figure 4a and Figure 4b each of the blocks (e.g., components) in Figure 4a and Figure 4b can be implemented by at least one of hardware, software, or firmware. For example, Figure 4a and Figure 4b some of the blocks in

[0095] Figure 5 can be implemented by software, and other blocks can be implemented by hardware or a combination of hardware and software. In

[0096] As Figure 5 shown, the time resources in the communication system can be divided on a frame basis. For example, the system frame of the communication system can be configured continuously in the time domain. The length of the system frame can be 10 milliseconds (ms). The system frame number (SFN) can be set to one of #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.

[0097] A system frame may include two half - frames. The length of a half - frame may be 5 ms. The half - frame located at the start region of the system frame may be referred to as "half - frame #0", and the half - frame located at the end region of the system frame may be referred to as "half - frame #1". A system frame may include 10 sub - frames. The length of a sub - frame may be 1 ms. The 10 sub - frames within a system frame may be referred to as sub - frame #0 to sub - frame #9.

[0098] Figure 6 is a conceptual diagram showing a first exemplary embodiment of a sub - frame in a communication system.

[0099] As Figure 6 shown, a sub - frame may include n time slots, where n may be a natural number. Accordingly, a sub - frame may be composed of one or more time slots.

[0100] Figure 7 is a conceptual diagram showing a first exemplary embodiment of a time slot in a communication system.

[0101] As Figure 7 shown, a time slot may include one or more symbols. For example, Figure 7 a time slot shown in may include 14 symbols. The length of a time slot may vary according to the number of symbols included in the time slot and the length of the symbols. Alternatively, the length of a time slot may vary according to the numerology.

[0102] The numerology applied to physical signals and channels in a communication system may be variable. The numerology may be adjusted to meet various technical requirements of the communication system. In a communication system applying OFDM waveform technology based on cyclic prefix (CP), the numerology may include sub - carrier spacing and CP length (or CP type). Table 1 may show a first exemplary embodiment of a method for configuring the numerology of a CP - OFDM - based communication system. Depending on the frequency band of the communication system operation, at least some of the numerologies in Table 1 may be supported. Additionally, the communication system may support numerologies not listed in Table 1.

[0103] [Table 1]

[0104]

[0105] When the sub - carrier spacing is 15 kHz (e.g., μ = 0), the length of a time slot may be 1 ms. In this case, a system frame may include 10 time slots. When the sub - carrier spacing is 30 kHz (e.g., μ = 1), the length of a time slot may be 0.5 ms. In this case, a system frame may include 20 time slots.

[0106] When the subcarrier spacing is 60 kHz (e.g., μ = 2), the length of a time slot can be 0.25 ms. In this case, one system frame can include 40 time slots. When the subcarrier spacing is 120 kHz (e.g., μ = 3), the length of a time slot can be 0.125 ms. In this case, one system frame can include 80 time slots. When the subcarrier spacing is 240 kHz (e.g., μ = 4), the length of a time slot can be 0.0625 ms. In this case, one system frame can include 160 time slots.

[0107] Symbols can be configured as downlink (DL) symbols, flexible (FL) symbols, or uplink (UL) symbols. A time slot consisting only of DL symbols can be referred to as a "DL time slot", a time slot consisting only of FL symbols can be referred to as an "FL time slot", and a time slot consisting only of UL symbols can be referred to as a "UL time slot".

[0108] The time slot format can be configured semi-statically by higher layer signaling (e.g., RRC signaling). Information indicating the semi-static time slot format can be included in the system information, and the semi-static time slot format can be configured specific to a cell. Additionally, the semi-static time slot format can be further configured for each terminal by terminal-specific higher layer signaling (e.g., RRC signaling). Flexible symbols in the cell-specific time slot format can be overwritten as downlink symbols or uplink symbols by terminal-specific higher layer signaling. Furthermore, the time slot format can be dynamically indicated by physical layer signaling (e.g., the slot format indicator (SFI) included in DCI). The semi-statically configured time slot format can be overwritten by the dynamically indicated time slot format. For example, a semi-statically configured flexible symbol can be overwritten as a downlink symbol or an uplink symbol by the SFI.

[0109] Reference signals may include Channel State Information-Reference Signal (CSI-RS), Sounding Reference Signal (SRS), Demodulation-Reference Signal (DM-RS), and Phase Tracking-Reference Signal (PT-RS). Channels may include Physical Broadcast Channel (PBCH), Physical Downlink Control Channel (PDCCH), Physical Downlink Shared Channel (PDSCH), Physical Uplink Control Channel (PUCCH), Physical Uplink Shared Channel (PUSCH), Physical Sidelink Control Channel (PSCCH), and Physical Sidelink Shared Channel (PSSCH). In the present invention, the control channel may refer to PDCCH, PUCCH, or PSCCH, and the data channel may refer to PDSCH, PUSCH, or PSSCH.

[0110] Figure 8 is a conceptual diagram showing a first exemplary embodiment of time-frequency resources in a communication system.

[0111] As Figure 8 shown, a resource composed of one OFDM symbol on the time axis and one subcarrier on the frequency axis may be defined as a "resource element (RE)". A resource composed of one OFDM symbol on the time axis and K subcarriers on the frequency axis may be defined as a "resource element group (REG)". The REG may include K REs. The 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 Figure 7 the shown time slot, N may be 14. N OFDM symbols may be used as a basic unit for resource allocation in the time domain.

[0112] In the present invention, an RB may refer to a common RB (CRB). Alternatively, an RB may refer to a physical RB (PRB) or a virtual RB (VRB). In a communication system, a CRB may refer to an RB that forms a set of consecutive RBs (e.g., a common RB grid) based on a reference frequency (e.g., point A). A carrier and / or a bandwidth part may be mapped onto the common RB grid. That is, a carrier and / or a bandwidth part may be configured with CRBs. The RBs or CRBs that form a bandwidth part may be referred to as PRBs, and the CRB index may be appropriately converted into a PRB index within the bandwidth part.

[0113] Downlink data may be transmitted through the PDSCH. The base station may send the configuration information (e.g., scheduling information) of the PDSCH to the terminal through the PDCCH. The terminal may obtain the configuration information of the PDSCH by receiving the PDCCH (e.g., Downlink Control Information (DCI)). For example, the configuration information of the PDSCH may include a Modulation Coding Scheme (MCS) for transmission / reception of the PDSCH, time resource information of the PDSCH, frequency resource information of the PDSCH, and feedback resource information of the PDSCH. The PDSCH may refer to a radio resource for transmitting and receiving downlink data. Alternatively, the PDSCH may refer to the downlink data itself. The PDCCH may refer to a radio resource for transmitting and receiving downlink control information (e.g., DCI). Alternatively, the PDCCH may refer to the downlink control information itself.

[0114] The terminal may perform a monitoring operation on the PDCCH to receive the PDSCH sent from the base station. The base station may notify the terminal of the configuration information for the PDCCH monitoring operation by using a high-layer message (e.g., a Radio Resource Control (RRC) message). The configuration information for the PDCCH monitoring operation may include Control Resource Set (CORESET) information and search space information.

[0115] CORESET information may include PDCCH DMRS information, PDCCH pre - encoding and decoding information, PDCCH timing information, etc. PDCCH DMRS may be the DMRS for demodulating the PDCCH. The PDCCH timing refers to the area where the PDCCH may potentially exist, which means it is the area where DCI can be transmitted. The PDCCH timing may also be referred to as a PDCCH candidate. The PDCCH timing information may include time resource information and frequency resource information for the PDCCH timing. In the time domain, the length of the PDCCH timing may be indicated in units of symbols. In the frequency domain, the size of the PDCCH timing may be indicated in RB units (e.g., in PRB units or CRB units).

[0116] Search space information may include a CORESET identifier (ID) associated with the search space, the periodicity of PDCCH monitoring, and / or the offset of PDCCH monitoring. The periodicity and offset of PDCCH monitoring may each be indicated in units of time slots. Additionally, the search space information may further include the index of the symbol at which the PDCCH monitoring operation starts.

[0117] The base station may configure a Bandwidth Part (BWP) for downlink communication. The BWP may be configured differently for each terminal. The base station may use high - layer signaling to notify the terminal of the BWP configuration information. High - layer signaling may refer to the transmission operation of system information and / or the transmission operation of RRC messages. The number of BWPs configured for a single terminal may be one or more. The terminal may receive the BWP configuration information from the base station and identify the configured BWP based on the received configuration information. When multiple BWPs are configured for downlink communication, the base station may activate one or more of the multiple BWPs. The base station may send the configuration information of the activated BWP to the terminal using at least one of high - layer signaling, Medium Access Control (MAC) control element (CE), or DCI. The base station may use the activated BWP to perform downlink communication. The terminal may identify the activated BWP by receiving the configuration information from the base station and perform downlink reception operations on the activated BWP.

[0118] In 5G NR, the multiple transmission and reception point (MTRP) technology refers to the technology in which a base station (e.g., gNB) communicates with a terminal by using multiple physically separated transmission reception points (TRPs). The MTRP technology can solve problems such as the degradation of the Quality-of-Service (QoS) experienced by terminals located at positions far from the base station (such as at the cell edge), and the inter-cell interference caused by signals received from base stations in different cells. In addition, the MTRP technology can provide an additional communication path for terminals located in a non-line of sight (NLOS) path (such as in the millimeter wave band).

[0119] According to the current 5G NR technical specifications, the MTRP technology is divided into a coherent joint transmission (CJT) scheme and a non-coherent joint transmission (NCJT) scheme. In the CJT scheme, the TRPs can cooperate with each other in a synchronous manner to support the terminal. In contrast, in the NCJT scheme, multiple TRPs support the terminal when determining the scheduling, pre-coded decoding matrix, modulation, and encoding and decoding schemes, without cooperation between the TRPs.

[0120] When a terminal receives signals from multiple TRPs or transmits signals to multiple TRPs, not only can a high transmission rate be achieved, but also the communication reliability can be improved. However, when a terminal communicates with multiple TRPs, a problem may occur in which the signal arrival time varies for each communication link between the terminal and each TRP.

[0121] When considering the communication between a base station and a terminal, the base station determines the timing advance (TA) value for synchronizing the uplink communication from the terminal. The base station can set the TA value based on the delay required for communicating with the terminal, and can provide the set TA value to the terminal. Accordingly, the terminal pre-transmits the uplink signal by the TA value assigned by the base station, thereby compensating for the propagation delay between the base station and the terminal.

[0122] In a multi-TRP environment, a terminal can communicate with two or more TRPs. In this case, the distances between the terminal and the respective TRPs can be different. In other words, the propagation delays between the terminal and each TRP can be different. However, since the 5G NR technical specification defines only a single TA for the terminal, the terminal needs to use the single TA to send signals to all TRPs. In this case, the TA value used for uplink transmission from the terminal to a specific TRP may be appropriate, but the TA value may not be appropriate for uplink transmission to other TRPs. In other words, due to the differences in propagation delays, signals simultaneously sent by the terminal to multiple TRPs may cause interference with the signals received from different TRPs at the base station. That is, from the perspective of the base station, due to the differences in propagation delays in the signals sent by the same terminal to different TRPs, inter-symbol interference (ISI) may occur.

[0123] ISI refers to the phenomenon where one symbol affects another due to the time delay caused by multipath fading. This phenomenon may occur when the delay of the orthogonal frequency division multiplexing (OFDM) signal sent by the terminal exceeds the length of the cyclic prefix (CP) of the OFDM signal, resulting in interference in the signal received at the base station.

[0124] According to the technical specifications of LTE TS 36.213 and 5G NR TS 38.213, in a coordinated multipoint (CoMP) environment, the TA is defined based on the primary cell (PCell) in the cell communicating with the terminal. This problem is solved by ensuring that the terminal does not communicate with the cell where the signal sent by the terminal based on the defined TA arrives outside the expected symbol timing.

[0125] However, in a 5G NR or 6G communication system, compared with conventional 5G NR, a wider frequency band is expected to be used, including the unlicensed millimeter wave band and the terahertz band. Accordingly, it is desirable to utilize more flexible numerology, subcarrier spacing (SCS), and CP. Generally, when a higher frequency band is used, a wider SCS and a shorter CP length are allocated. Therefore, when the terminal selects a TRP for communication based on the TA, SCS, and CP assigned by the reference TRP, as in current 5G NR, the number of TRPs available for communication may become limited. In addition, in an MTRP environment, when TRPs that do not meet the conditions according to the current technical specification are excluded from communication, there is a problem of reduced transmission rate.

[0126] Therefore, in a 6G terahertz communication system that requires high transmission rates, ultra-low latency, and highly reliable communication, the existing method of selecting a reference TRP and requiring all TRPs to use the same TA, SCS, and CP as the reference TRP is not appropriate. Therefore, it is necessary to define a communication TRP selection method, a resource allocation scheme, and the parameters required thereof that take into account the propagation delay of multiple TRPs that can be used to communicate with the terminal.

[0127] Before describing the method according to the present invention, an overview of the timing adjustment related technology described in the 3GPP technical specifications is provided.

[0128] Section 4.2.3 of 3GPP technical specification TS 36.213 describes the transmission timing adjustment. The general overview is as follows:

[0129] When receiving a timing advance command or a timing adjustment indication for a timing advance group (TAG) including the primary cell or the PSCell, the UE can adjust the uplink transmission timing of the PUCCH, PUSCH, and SRS for the primary cell or the PSCell based on the received timing advance command or timing adjustment indication.

[0130] When the secondary cell and the primary cell belong to the same TAG, the uplink transmission timing of the PUSCH and SRS for the secondary cell is the same as the uplink transmission timing of the primary cell. When the primary cell within the TAG uses frame structure type 1 and the secondary cell within the same TAG uses frame structure type 2 or frame structure type 3, the UE can assume N TA ≥ 624.

[0131] When the UE is configured with an SCG, if the secondary cell and the PSCell belong to the same TAG, the uplink transmission timing of the PUSCH and SRS for the secondary cell that is not the PSCell is the same as the uplink transmission timing of the PSCell.

[0132] When receiving a timing advance command or a timing adjustment indication for a TAG that does not include the primary cell or the PSCell, and all serving cells within the TAG use the same frame structure type, the UE may need to adjust the uplink transmission timing of the PUSCH and SRS for all secondary cells within the TAG based on the received same timing advance command, or adjust the uplink transmission time of the PUSCH and SRS for all secondary cells within the TAG based on the received same timing adjustment indication.

[0133] When receiving a timing advance command or a timing adjustment indication for a TAG that does not include the primary cell or the PSCell, if the serving cell within the TAG uses a different frame structure type compared to other serving cells within the same TAG, the UE may need to adjust the uplink transmission timing of the PUSCH and SRS for all secondary cells within the TAG based on the received timing advance command or timing adjustment indication, using N TAoffset = 624, regardless of the frame structure type of the serving cell. Here, the uplink transmission timing for the PUSCH and SRS is the same for all secondary cells within the TAG.

[0134] Subsequently, a method for determining the TA value is described, but the detailed content is omitted.

[0135] In addition, Section 4.2 of 3GPP TS 38.213 describes the transmission timing adjustment as follows. A general overview is provided as follows:

[0136] The UE may be configured with an N TA,offset value, which is the timing advance offset for the serving cell by means of n-TimingAdvanceOffset for the serving cell. If the UE does not receive the n-TimingAdvanceOffset for the serving cell, the UE may determine the default N TA,offset value as the timing advance offset for the serving cell as described in 3GPP TS 38.133.

[0137] When the UE is configured with two uplink carriers for the serving cell, the same timing advance offset value, i.e., N TA,offset is applied to both carriers.

[0138] When receiving a timing advance command for the TAG, the UE may adjust the uplink transmission timing of the PUSCH, SRS, and PUCCH for all serving cells within the TAG based on the received timing advance command and N TA,offset , expecting N TA,offset to be the same for all serving cells within the TAG. Here, the uplink transmission timing for the PUSCH, SRS, and PUCCH is the same for all serving cells within the TAG.

[0139] Since the details disclosed in the TS document can be referenced in the corresponding technical specification, further content is omitted.

[0140] 5G NR supports communication processes that utilize MTRP to improve the performance and efficiency of MIMO. In MTRP technology, the selection between CJT and NCJT schemes can be determined based on the environment of the cell where the TRP is located and the backhaul link connectivity. The selection between these two schemes can determine whether multiple TRPs cooperate to support the terminal in the CJT scheme, or whether each TRP independently supports the terminal in the NCJT scheme. Various problems caused by simultaneous communication between multiple TRPs and a terminal in the MTRP environment have been discussed, among which there may be a problem of ISI occurring at the TRP with a relatively large propagation delay due to the difference in propagation delays between the terminal and the corresponding TRP. In the currently proposed 5G NR, this problem is solved by configuring the terminal to communicate using the TA corresponding to the propagation delay with the reference TRP. Additionally, when using the corresponding TA, the terminal is prevented from communicating with the TRP whose signal it sends does not reach within the CP length.

[0141] Figure 9a is a conceptual diagram showing the downlink reception timing and uplink transmission timing configured based on the reference TRP and TA in the 5G NR MTRP environment according to the current NR technical specification.

[0142] Figure 9a Shows a case where four TRPs can be used to communicate with a UE, and these TRPs are described as the first TRP, the second TRP, the third TRP, and the fourth TRP. In this case, it is assumed that the reference TRP is the first TRP. Here, the reference TRP may refer to the TRP that sets the TA value for the UL communication of the UE. Generally, the reference TRP may be the TRP with the best channel conditions for the UE. The TRP with the best channel conditions may be the TRP closest to the UE. For ease of description, Figure 9a assume a scenario where the distance from the UE to each TRP increases sequentially from the first TRP to the fourth TRP. In other words, the distance between the UE and the first TRP is the shortest, while the distance between the UE and the fourth TRP is the longest. Figure 9a Each of the first to fourth TRPs shown can be a TRP capable of communicating with the UE.

[0143] Each of the first to fourth TRPs can send the first OFDM symbol 910 at the time T0 set as the reference time, and sequentially send the second OFDM symbol 920. The OFDM symbols sent from the TRP can have the same form. For example, as is well known, the second OFDM symbol 920 can be composed of a CP 921 and a data symbol 922.

[0144] When all four TRPs send OFDM symbols to the UE at time T0, the time for the UE to receive DL data from each TRP can vary according to the distance between the UE and each TRP. In other words, based on the distance between the UE and each TRP, the UE can receive OFDM symbols sent by each TRP with different propagation delays. Assume the reference TRP is Figure 9a the first TRP in

[0145] When the first to fourth TRPs send OFDM symbols with the same CP length, according to the DL reception timing 930 at the UE, the UE can receive the OFDM symbol sent by the first TRP at time T0 after a delay of the first propagation delay time 931. Additionally, the UE can receive the OFDM symbol sent by the second TRP at time T0 after a delay of the second propagation delay time 932. Similarly, the UE can receive the OFDM symbol sent by the third TRP at time T0 after the third propagation delay time 933, and receive the OFDM symbol sent by the fourth TRP at time T0 after the fourth propagation delay time 934. In the following description, the first propagation delay time 931 is referred to as τ TRP1 , the second propagation delay time 932 is referred to as τ TRO2 , the third propagation delay time 933 is referred to as τ TRP3 , and the fourth propagation delay time 934 is referred to as τ TRP4 .

[0146] As described above, in 5G NR, the TA value is determined as a single value based on the reference TRP. In other words, according to the 5G NR technical specification, a single TA value can be set based on the distance between the first TRP and the UE. Therefore, the TA values for the first to fourth TRPs can be determined based on the first propagation delay time 931 of τ TRP1 . The TA value can be determined based on N TA,offset , the timing advance offset for the serving cell, which, as described above, is set by n-TimingAdvanceOffset signaled from the serving cell. The same TA value can be set for the corresponding TRP.

[0147] When the same TA value based on the first propagation delay time 931 is set for the first to fourth TRPs as described above, the uplink transmission can occur at a time earlier than T0 by the TA value 941, as shown in the "UL transmission timing 940" at the UE.

[0148] Figure 9bIt is a conceptual diagram showing uplink transmission timing and expected uplink transmission timing configured based on a reference TRP and TA in a 5G NR MTRP environment according to the current NR technical specification.

[0149] As referenced Figure 9a described, the UL transmission timing 940 at the UE can be determined based on the first propagation delay time 931 of the reference TRP which is the first TRP. Thus, for each TRP, the UL reception timing 950 at each TRP can be different. This assumes the same scenario as Figure 9a where the distance between the UE and the first TRP is the shortest and the distances increase in the order of the second TRP, the third TRP, and the fourth TRP. In this case, since the first TRP is the reference TRP and the TA value is determined based on the first propagation delay time 931 between the first TRP and the UE, ideally, the OFDM symbol transmitted by the UE can be received at the reference time T0.

[0150] However, depending on the distance, each of the second TRP to the fourth TRP can receive the signal at a time later than T0 which is the reference time. When the second TRP receives the first OFDM symbol from the UE and then receives the second OFDM symbol, the second TRP can receive the second OFDM symbol within the CP duration of the second OFDM symbol of the first TRP. However, in the case of the third TRP and the fourth TRP, the first OFDM symbol can be received even after the CP duration of the second OFDM symbol of the first TRP. Accordingly, in the case of the third TRP, the data symbol of the second OFDM symbol of the first TRP is received within the reception interval of the first OFDM symbol, resulting in an ISI occurrence duration 951. The ISI occurrence duration 952 can also occur in the case of the fourth TRP.

[0151] From the perspective of each TRP, the UL transmission timing 960 at the UE is presented as follows. From the perspective of the first TRP, the UE transmits the OFDM symbol earlier by TA 941. From the perspective of the second TRP, the UE transmits the OFDM symbol later than TA 941 but still within the CP duration. However, from the perspective of the third TRP and the fourth TRP, the UE transmits the OFDM symbol significantly later than TA941, that is, at a time exceeding the CP duration. Thus, the ISI occurrence durations 951 and 952 can occur in the case of the third TRP and the fourth TRP.

[0152] According to the current LTE and NR technical specifications, as described above, a TRP with a relatively large propagation delay, such as Figure 9bThe third TRP and the fourth TRP in [the context] do not continue to communicate with the UE due to the occurrence of ISI. According to the solutions provided by the current LTE and NR technical specifications for solving the ISI problem caused by propagation delay differences, when the reference TRP uses a parameter set with a wider SCS for communicating with the UE, the CP length becomes shorter, thus limiting the number of TRPs available for communicating with the UE. In other words, the number of TRPs that can be utilized in the MTRP environment can be restricted.

[0153] In future 6G communication systems, using a wider range of frequency bands, such as unlicensed millimeter wave bands or terahertz bands, is expected to support more flexible parameter sets. If, as is currently the case, in both 5G NR and future 6G communication systems, TRPs are selected and resources are allocated only based on the propagation delay of the reference TRP, the number of TRPs that can communicate with the UE can be restricted, as described above. The limitation in the number of TRPs may lead to the problem that a wireless communication system (such as 6G) may not be able to achieve ultra-high capacity, ultra-low latency, and large-scale connection communication services.

[0154] Therefore, the present invention proposes a method for maximizing the number of communication links with TRPs not only in a 6G communication environment using a more flexible parameter set than current 5G NR but also in a 5G NR environment where multiple TRPs are intended to support a single UE. In other words, the present invention proposes methods for selecting the allocation of TRPs and parameter sets, SCS, CP, and TA, which enable the UE to establish communication links with as many TRPs as possible. To this end, the present invention described below can consider the propagation delays of multiple TRPs.

[0155] The present invention defines a propagation delay threshold that the UE can support in the MTRP environment, thereby enabling the selection of TRPs available for communication and the reference TRP. Additionally, the present invention describes a method in which the UE delivers information about the propagation delay with the TRP, and the UE can communicate with the TRP via the backhaul between TRPs (e.g., in the CJT scheme) or via the UE itself (e.g., in the NCJT scheme).

[0156] According to the present invention described below, a scenario can be considered where four TRPs (e.g., TRP A, TRP B, TRP C, and TRP D) are intended to support a single UE in the MTRP NCJT environment, where the TRPs support the UE without cooperation between the TRPs. The number of TRPs is not limited to four, and the present invention can also be applied to cases where three or fewer TRPs or five or more TRPs communicate with the UE. However, for ease of description, the following description assumes the case where four TRPs communicate with the UE.

[0157] When a total of four TRPs attempt to communicate with the UE, the UE sends a PRACH preamble to each of all the TRPs, and each TRP measures the propagation delay and the reference signal received power (RSRP) of the PRACH preamble sent by the terminal. Each TRP sends information about the measured propagation delay and RSRP value of the PRACH preamble to the terminal. The present invention proposes a method in which the terminal selects the TRPs available for communication and further selects a reference TRP based on the received information, and the reference TRP allocates a parameter set, SCS, and CP and TA of the terminal based on the information about the propagation delays of the other TRPs. Since the terminal can only support one parameter set, which means only support one SCS, all the TRPs connected to the terminal need to be allocated the same parameter set, that is, the same SCS and CP. Accordingly, the present invention proposes a method in which the reference TRP determines the parameter set, SCS, CP, and TA values by considering the communication environment between the terminal and the other TRPs, so that all the TRPs are allocated the same parameter set, SCS, CP, and TA.

[0158] First, an overview of the operation according to the present invention described below is provided. As previously mentioned, when a total of four TRPs attempt to communicate with the terminal, the UE can send a PRACH preamble to each of all the TRPs. In response, each of all the TRPs can measure the propagation delay and RSRP of the PRACH preamble sent by the UE. Each of all the TRPs can send information about the measured propagation delay and RSRP value of the PRACH preamble to the UE. The UE can select the TRPs available for communication and the reference TRP based on the information received from the TRPs. According to an exemplary embodiment of the present invention, the reference TRP can allocate a parameter set, SCS, and CP and TA of the UE based on the information about the propagation delays of the other TRPs. Since the UE can only support one parameter set, which means only support one SCS, all the TRPs connected to the UE need to be allocated the same parameter set, that is, the same SCS and CP. Accordingly, the present invention proposes a method in which the reference TRP determines the parameter set, SCS, CP, and TA values by considering the communication environment between the UE and the other TRPs, so that all the TRPs are allocated the same parameter set, SCS, CP, and TA.

[0159] The process according to the present invention described below may include steps (1) to (6) proposed below, and the methods for performing these steps are described. Steps (1) to (6) described below are as follows.

[0160] (1) The UE transmits a PRACH preamble to each of all the TRPs to which it attempts to communicate, and measures the propagation delay and RSRP of each PRACH preamble of all the TRPs.

[0161] (2) Each of all the TRPs transmits to the UE information on the propagation delay and RSRP of the PRACH preamble transmitted by the UE.

[0162] (3) The UE selects a TRP for communication and a reference TRP based on the propagation delay and RSRP received from all the TRPs.

[0163] (4) The UE delivers to the reference TRP information on the propagation delay of the selected TRP for communication.

[0164] (5) The reference TRP sets the TA value to be assigned to the UE, and the parameter set, SCS, and CP value to be used by all the TRPs based on the information on the propagation delay of all the selected TRPs.

[0165] (6) In the environments of both CJT and NCJT, the reference TRP delivers the TA value to the UE, and delivers to the other selected TRPs information on the parameter set, SCS, and CP value to be assigned to each selected TRP.

[0166] The above steps (1) to (6) can all be executed, or some steps can be omitted. In addition, steps (1) to (6) can be appropriately modified or adjusted based on the scheme described below.

[0167] In addition, when executing the above steps (1) to (6), if the TRP operates in the CJT environment, the TRP can exchange information via the backhaul. If the TRP operates in the NCJT environment, the UE can relay the information. Even in the NCJT environment, a backhaul can be optionally formed so that information exchange between TRPs can be achieved in some cases.

[0168] In the present invention described below, the transmission scheme may vary depending on whether the reference TRP and other communication TRPs that are not the reference TRP are connected to the same base station or different base stations. If the reference TRP and other communication TRPs that are not the reference TRP are connected to the same base station, both the reference TRP and the communication TRPs that are not the reference TRP may utilize the radio resource control (RRC) transmission scheme. On the other hand, if the reference TRP and other communication TRPs that are not the reference TRP are connected to different base stations, since the UE can establish an RRC connection with only one base station, assuming that the UE is in an RRC connection state with the base station connected to the reference TRP, the UE can be considered to be in a multi-connection state with the base station connected to the communication TRP that is not the reference TRP via signaling radio bearer 3 (SRB3). The UE and the base station connected to the communication TRP that is not the reference TRP can send and receive information such as secondary node (SN) RRC reconfiguration, SN RRC reconfiguration complete, SN measurement report, and SN UE assistance information via SRB3.

[0169] [A] Process for selecting communication TRP and reference TRP in an MTRP environment

[0170] The present invention describes a resource allocation method considering propagation delay in an MTRP environment where four TRPs (e.g., TRP A, TRP B, TRP C, and TRP D) attempt to support a single UE. As described above, if the propagation delay between the UE and the TRP exceeds the CP length of the OFDM symbol used for communication by the UE, the signal transmitted by the UE may overlap with another OFDM symbol, resulting in ISI. The present invention first describes the process by which the UE selects the communication TRP and the reference TRP. Specifically, the UE can define the propagation delay based on the set of parameters that it itself can support, and can select the communication TRP and the reference TRP based on the propagation delay and the RSRP value received from the corresponding TRP.

[0171] Figure 10 It is a sequence diagram showing the process by which the UE sends PRACH preambles to multiple TRPs.

[0172] Figure 10 Shows as the execution of Figure 10UE 1001 for the operation entity and four different TRPs 1011, 1012, 1013, and 1014. As described above, multiple TRPs may include two or more TRPs, and it should be noted that only four TRPs are shown for ease of description. Each of UE 1001 and TRPs 1011, 1012, 1013, and 1014 may include Figure 2 at least a portion of the components exemplified in Figure 3 . Additionally, when applying the MIMO scheme, it may include Figure 4a and / or Figure 4b at least a portion of the components in Figures 2 to 4b . When assuming a system that transmits OFDM symbols, it may include

[0173] Before referring to Figure 10 , it is assumed that UE 1001 has received synchronization signal blocks (SSBs) from all TRPs 1011, 1012, 1013, and 1014. Therefore, UE 1001 can know all the TRPs with which it can communicate.

[0174] As Figure 10As shown, at step S1000, UE 1001 may send a PRACH preamble to TRP A 1011. When UE 1001 sends a PRACH preamble to TRP A 1011, UE 1001 may know the RACH opportunity of TRP A 1011. Additionally, at step S1002, UE 1001 may send a PRACH preamble to TRP B 1012. When UE 1001 sends a PRACH preamble to TRP B 1012, UE 1001 may know the RACH opportunity of TRP B 1012. In the same way, at step S1004, UE 1001 may send a PRACH preamble to TRP C 1013, and at step S1006, UE 1001 may send a PRACH preamble to TRP D 1014. Therefore, when UE 1001 sends PRACH preambles to TRP C 1013 and TRP D 1014, UE 1001 may know the RACH opportunities of TRP C 1013 and TRP D 1014.

[0175] The RACH opportunities of TRPs 1011, 1012, 1013, and 1014 may be the same time. UE 1001 may configure different RACH opportunities for TRPs 1011, 1012, 1013, and 1014 to prevent preamble conflicts between TRPs 1011, 1012, 1013, and 1014. For example, different RACH opportunities for each TRP may be configured by using the identifier (ID) of each TRP.

[0176] As another example, when UE 1001 can utilize multiple panels, that is, when UE 1001 has multiple panels and can use them, UE 1001 may allocate different panels to TRPs to distinguish preambles between TRPs 1011, 1012, 1013, and 1014 based on the corresponding panels. More specifically, when UE 1001 has multiple panels, UE 1001 may use the orthogonality between panels to prevent PRACH preamble conflicts between TRPs by setting preamble indexes separately for each panel. In this case, steps S1000 to S1006 may also be performed simultaneously.

[0177] In addition, the UE 1001 can send PRACH preambles corresponding to each TRP. For example, the UE 1001 can send the UE PRACH preamble A to the TRP A 1011, the UE PRACH preamble B to the TRP B 1012, the UE PRACH preamble C to the TRP C 1013, and the UE PRACH preamble D to the TRP D 1014. In this case, the RACH procedure can be executed according to a two-step procedure or a four-step procedure. When the RACH procedure is a four-step procedure, the UE PRACH preamble can be sent in the form of "Message 1 (Msg1)", and when the RACH procedure is a two-step procedure, the UE PRACH preamble can be sent in the form of "Message A (MsgA)".

[0178] Accordingly, at step S1000, the TRP A 1011 can receive the PRACH preamble from the UE 1001, at step S1002, the TRP B 1012 can receive the PRACH preamble from the UE 1001, at step S1004, the TRP C 1013 can receive the PRACH preamble from the UE 1001, and at step S1006, the TRP D 1014 can receive the PRACH preamble from the UE 1001.

[0179] At step S1000, the TRP A 1011 can measure the PRACH preamble received from the UE 1001. The measurement of the PRACH preamble can include measuring the propagation delay of the PRACH preamble and the RSRP value of the PRACH preamble. In addition, at step S1002, the TRP B 1012 can measure the propagation delay of the PRACH preamble received from the UE 1001 and the RSRP value of the PRACH preamble. In the same way, at step S1004, the TRP C 1013 can measure the propagation delay of the PRACH preamble received from the UE 1001 and the RSRP value, and at step S1006, the TRP D 1014 can measure the propagation delay of the PRACH preamble received from the UE 1001 and the RSRP value. When the propagation delay and the RSRP value measured at the TRP A 1011 to the TRP D 1014 are shown in a table, an example as shown in Table 2 below can be given.

[0180] [Table 2]

[0181] Propagation delay RSRP value UE PRACH preamble A PD_A RSRP_95 UE PRACH preamble B PD_B RSRP_90 UE PRACH preamble C PD_C RSRP_85 UE PRACH preamble D PD_D RSRP_89

[0182] In Table 2, the PRACH preamble sent from UE 1001 to TRP A 1011 is UE PRACH preamble A. Therefore, the propagation delay measured at TRP A 1011 after receiving UE PRACH preamble A can be expressed as PD_A, and the RSRP value of UE PRACH preamble A can be RSRP_95. In Table 2, the PRACH preamble sent from UE 1001 to TRP B 1012 is UE PRACH preamble B, and the propagation delay measured at TRP B 1012 after receiving UE PRACH preamble B can be expressed as PD_B, while the RSRP value of UE PRACH preamble B can be RSRP_90. Additionally, in Table 2, the PRACH preamble sent from UE 1001 to TRP C 1013 is UE PRACH preamble C, and the propagation delay measured at TRP C 1013 after receiving UE PRACH preamble C can be expressed as PD_C, while the RSRP value of UE PRACH preamble C can be RSRP_85. In the same way, in Table 2, the PRACH preamble sent from UE 1001 to TRP D 1014 is UE PRACH preamble D, and the propagation delay measured at TRP D 1014 after receiving UE PRACH preamble D can be expressed as PD_D, while the RSRP value of UE PRACH preamble D can be RSRP_89.

[0183] Through the above Figure 10 process, each of the TRPs 1011, 1012, 1013, and 1014 that can communicate with UE 1001 can utilize the UE PRACH preamble sent by UE 1001 to obtain the propagation delay and RSRP value. Hereinafter, the process of each of the TRPs 1011, 1012, 1013, and 1014 delivering the value (or information) obtained for UE 1001 will be described.

[0184] On the other hand, when a PRACH preamble is received at each of TRPs 1011 to 1014, each TRP can notify the base station to which it is connected of the reception of the PRACH preamble.

[0185] Figure 11 is a sequence diagram showing a case where multiple TRPs provide the propagation delay and RSRP value to the UE.

[0186] Figure 11 shows UE 1001 and four different TRPs 1011, 1012, 1013, and 1014 as entities that perform Figure 11 the operations. At Figure 11In it, the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 use the same reference numerals as those described in Figure 10 . In other words, the configurations of the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 as entities that perform the operations in Figure 11 can be the same as those described in Figure 10 . Additionally, the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 as entities that perform the operations in Figure 11 can be in a state where the operations in Figure 10 have been pre-executed.

[0187] As shown in Figure 11 , at step S1100, the TRP A 1011 can send information about its TRP ID, RSRP value, and propagation delay to the UE 1001. Here, the TRP ID can be TRP ID_A, which is the ID of the TRP A 1011. Additionally, the information about the RSRP value and propagation delay sent by the TRP A 1011 at step S1100 can be the information obtained in the process of Figure 10 . In other words, the RSRP value sent by the TRP A 1011 can be RSRP_95, and the propagation delay can be PD_A, as exemplified in Table 2. Therefore, the UE 1001 can receive information about the TRP ID, RSRP, and propagation delay from the TRP A 1011.

[0188] At step S1102, the TRP B 1012 can send information about its TRP ID, RSRP value, and propagation delay to the UE 1001. Here, the TRP ID can be TRP ID_B, which is the ID of the TRP B 1012. Additionally, the information about the RSRP value and propagation delay sent by the TRP B 1012 at step S1102 can be the information obtained in the process of Figure 10 . For example, the RSRP value sent by the TRP B 1012 can be RSRP_90, and the propagation delay can be PD_B, as exemplified in Table 2. Therefore, the UE 1001 can receive information about the TRP ID, RSRP, and propagation delay from the TRP B 1012.

[0189] Additionally, at step S1104, the TRP C 1013 can send information about its TRP ID, RSRP, and propagation delay to the UE 1001. Here, the TRP ID can be TRP ID_C, which is the ID of the TRP C 1013. Additionally, the information about the RSRP and propagation delay sent by the TRP C 1013 at step S1104 can be the information obtained in the process of Figure 10The information obtained during the process. For example, the RSRP value sent by TRP C 1013 can be RSRP_85, and the propagation delay can be PD_C, as shown in the example in Table 2. Therefore, UE 1001 can receive information about the TRP ID, RSRP, and propagation delay from TRP C 1013.

[0190] In the same way, in step S1106, TRP D 1014 can send information about its TRP ID, RSRP, and propagation delay to UE 1001. Here, the TRP ID can be TRP ID_D, which is the ID of TRP D 1014. Additionally, the information about RSRP and propagation delay sent by TRP D 1014 in step S1106 can be the information obtained during Figure 10 the process. For example, the RSRP value sent by TRP D 1014 can be RSRP_89, and the propagation delay can be PD_D, as shown in the example in Table 2. Therefore, UE 1001 can receive information about the TRP ID, RSRP, and propagation delay from TRP D 1014.

[0191] Based on the above description, an example of the information sent by each of TRP 1011, 1012, 1013, and 1014 to UE 1001 can be provided as shown in Table 3 below.

[0192] [Table 3]

[0193]

[0194]

[0195] Meanwhile, in each of steps S1100 to S1106, the TRP ID can be omitted. When UE 1001 has obtained the IDs of all TRP 1011, 1012, 1013, and 1014 through the SSBs received from TRP1011, 1012, 1013, and 1014 respectively, the TRP ID can be omitted. In another example, even when UE 1001 has obtained the IDs of all TRP 1011, 1012, 1013, and 1014 through the SSB, the TRP ID can still be included to allow UE 1001 to be able to identify from which TRP it receives the information about RSRP and propagation delay delivery.

[0196] In yet another example, when UE 1001 can identify each of TRP 1011, 1012, 1013, and 1014 by pairing or linking the UE PRACH preamble with the transmit beam and receive beam or by matching the panel with the TRP, the TRP ID can be omitted.

[0197] The transmission of the RSRP value and propagation delay from each of TRPs 1011, 1012, 1013, and 1014 to UE 1001 can be performed via a base station connected to TRPs 1011, 1012, 1013, and 1014.

[0198] UE 1001 can comprehensively utilize all the TRP IDs of TRPs 1011, 1012, 1013, and 1014, as well as the propagation delay and RSRP value of the PRACH preamble obtained through the Figure 11 process to select a TRP for communication and further select a reference TRP in subsequent processes. A more detailed description will be provided with reference to the subsequent drawings.

[0199] In the Figure 11 process, when UE 1001 is in the RRC connected state with the base station connected to the TRP intended for communication, the corresponding TRP can send information about its TRP ID and the propagation delay and RSRP value of the PRACH preamble to UE 1001 through SIB, downlink control information (DCI), or MAC-CE. In another example, since UE 1001 has sent a UE PRACH preamble through Msg1 or MsgA in the Figure 10 process, UE 1001 can receive information about the TRP ID and the propagation delay and RSRP value of the PRACH preamble from the corresponding TRP through Msg2 or MsgB. In yet another example, when UE 1001 is in the RRC connected state with the base station connected to the TRP, UE 1001 can receive information about the TRP ID and the propagation delay and RSRP value of the PRACH preamble through new RRC signaling. Additionally, when the base station in the RRC connected state with UE 1001 provides information about an instruction to report a communication TRP and a reference TRP to UE 1001, the base station can send such information to UE 1001 through a UE information request in the RRC signaling.

[0200] When the TRP is connected to a base station other than the base station with which UE 1001 is in the RRC connected state, the TRP can send information about the TRP ID and the propagation delay and RSRP value of the PRACH preamble to UE 1001 through SRB3 signaling. In another example, when the TRP is connected to a base station other than the base station with which UE 1001 is in the RRC connected state, the TRP can send information about the TRP ID and the propagation delay and RSRP value of the PRACH preamble to UE 1001 through SIB or DCI.

[0201] In the aboveFigure 10 and Figure 11 In the process of, it has been described that UE 1001 sends a PRACH preamble to each of TRPs 1011, 1012, 1013, and 1014, and receives information about the TRP ID, the propagation delay of the PRACH preamble, and the RSRP value from each of TRPs 1011, 1012, 1013, and 1014 through a response such as Msg2 or MsgB or through various types of signaling. However, the process by which UE 1001 receives information about the TRP ID, the propagation delay of the PRACH preamble, and the RSRP value from each of TRPs 1011, 1012, 1013, and 1014 can also be performed using other schemes. For example, UE 1001 can obtain the RSRP value by receiving the SSB broadcast by each of TRPs 1011, 1012, 1013, and 1014 and measuring the RSRP of the received SSB for each of TRPs 1011, 1012, 1013, and 1014.

[0202] In addition, the present invention contemplates an environment with a minimum delay spread in an expected future 6G environment. However, in an environment with significant multipath propagation, all TRPs can additionally send information about their respective delay spreads, as well as information about the TRP ID, propagation delay, and RSRP, to the UE.

[0203] The process described above Figure 11 does not consider the conflict scenario between UEs, that is, the preamble conflict in the contention-based random access process. However, the present invention may further include a process in which when the preamble sent by a UE in the contention-based random access process conflicts with the preamble sent by another UE, the preamble is retransmitted once or n times (where n is an integer equal to or greater than 2).

[0204] In addition, when random access is not successfully performed within a predetermined number of attempts due to a conflict between UEs, UE 1001 and / or the corresponding TRP can set the TA value by using the propagation delay (i.e., TA value) obtained from a previous operation, even if it may be somewhat inaccurate.

[0205] Information related to the TA value described in the present invention can be sent as the measured propagation delay value itself. In another example, information related to the TA value described in the present invention can be sent as a specific index value that matches the TA value quantized based on a predetermined resolution. In this case, the index that matches the TA value can be the index corresponding to the quantized TA value with the minimum error relative to the actual TA value. In another example, the index that matches the TA value can be the minimum value among the values greater than the quantized TA value, which are classified based on the resolution. The relationship between the TA value and the resolution in the quantization process can be shown in a figure.

[0206] On the other hand, operations performed at a higher layer in the process described in Figure 12 , such as operations performed at the MAC layer or the RRC layer, can all be performed under the control of the base station. Therefore, the TRPs 1011, 1012, 1013, and 1014 can perform operations of sending or receiving corresponding information under the control of the base station. Additionally, when necessary, the control entity for all or part of the operations performed at the physical layer can also be the base station connected to the corresponding TRPs 1011, 1012, 1013, and 1014.

[0207] Figure 12 is a sequence diagram showing the process by which the UE determines the communication TRP and the reference TRP.

[0208] Figure 12 shows the UE 1001 and four different TRPs 1011, 1012, 1013, and 1014 as entities performing the operations of Figure 12 . In Figure 12 , the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 use the same reference numerals as those described in Figure 10 and Figure 11 . In other words, the configurations of the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 as entities performing the operations of Figure 12 can be the same as the configurations described in Figure 10 and Figure 11 . Additionally, the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 as entities performing the operations of Figure 12 can be in a state where the operations of Figure 10 and / or Figure 11 have been pre-executed. In the following description of the operations of Figure 12 , for ease of description, it is assumed that the operations of Figure 10 and / or Figure 11 have been performed.

[0209] As Figure 12As shown, at step S1200, the UE 1001 may select a TRP for communication (hereinafter referred to as "communication TRP") and a reference TRP based on the information received from the TRP A 1011, TRP B 1012, TRP C 1013, and TRP D 1014. In other words, the communication TRP and the reference TRP may be determined based on the information received from the TRP 1011, 1012, 1013, and 1014 regarding the propagation delay and RSRP value of the preamble. According to Figure 11 Table 3 of

[0210] In the present invention, the propagation delay threshold PD th may be set to determine the communication TRP. The propagation delay threshold may represent the maximum allowable propagation delay set by the UE 1001. In other words, the UE 1001 may not perform communication with a TRP having a propagation delay longer than the propagation delay threshold. Therefore, a TRP having a propagation delay exceeding the propagation delay threshold may be excluded from the communication TRP.

[0211] The propagation delay threshold according to the present invention may be (pre)-configured by one of two schemes. When the UE 1001 autonomously sets the propagation delay threshold, the UE 1001 may set the CP corresponding to the parameter set with the minimum SCS supported by the UE 1001 as the propagation delay threshold. In other words, the propagation delay threshold may be determined based on the capability information of the UE 1001.

[0212] In another example, the propagation delay threshold may be set by determining the maximum allowable CP according to the delay requirement of the UE 1001 or the higher layer of the UE 1001 and setting the propagation delay threshold based on the determined maximum CP.

[0213] When the propagation delay threshold is set by the base station connected to UE 1001, the base station can determine the maximum allowable CP by considering the latency requirements demanded by the network or the frequency bands supported by the network, and set the propagation delay threshold according to the determined maximum CP. Even in this case, the base station can also consider the capability information of UE 1001 received from UE 1001 when determining the propagation delay threshold. When setting the propagation delay threshold, the base station can send information about the propagation delay threshold to UE 1001 via a specific TRP. In this case, the propagation delay threshold can be pre-delivered to UE 1001 through the MeasConfig of the RRC reconfiguration message.

[0214] As shown in Table 4 below, an example can be given where, based on the propagation delay obtained through the Figures 10 to 11 process, the TRPs that satisfy the propagation delay threshold for UE 1001 are determined as TRP A 1011, TRP B 1012, and TRP C 1013.

[0215] [Table 4]

[0216] TRP Propagation delay RSRP value TRP A (TRP ID_A) <![CDATA[PD_A < PD th > RSRP_95 TRP B (TRP ID_B) <![CDATA[PD_B < PD th > RSRP_90 TRP C (TRP ID_C) <![CDATA[PD_C < PD th > RSRP_85 TRP D (TRP ID_D) <![CDATA[PD th <PD_D]]> RSRP_89

[0217] As shown in the example in Table 4, the propagation delay PD_D between TRP D 1014 and UE 1001 is greater than the propagation delay threshold PD th , however, the propagation delays PD_A, PD_B, and PD_C of TRP A 1011, TRP B 1012, and TRP C 1013 are less than the propagation delay threshold PD th . Therefore, UE 1001 can determine TRP A 1011, TRP B 1012, and TRP C 1013 as the communication TRPs.

[0218] In addition, when determining the reference TRP, UE 1001 can select one of the communication TRPs as the reference TRP, and the communication TRPs are TRP A 1011, TRP B 1012, and TRP C 1013. Various methods can be used to determine the reference TRP. However, since the present invention only describes the selection process based on the propagation delay and the RSRP value, the following description focuses on the method using the RSRP value. However, the present invention is not limited to only using the RSRP value when determining the reference TRP, and other factors such as the TRP load and the required quality of the transmitted data can also be considered.

[0219] The UE 1001 may configure the TRP with the highest RSRP among the communication TRPs (i.e., TRP A 1011, TRP B 1012, and TRP C 1013) as the reference TRP. According to the example in Table 3, the RSRP value received from TRP A 1011 is RSRP_95, the RSRP value received from TRP B 1012 is RSRP_90, and the RSRP value received from TRP C 1013 is RSRP_85. Therefore, the UE 1001 may determine TRP A 1011 with the highest RSRP value as the reference TRP.

[0220] In Figure 12 it has been described the process of setting a propagation delay threshold, determining a communication TRP based on the propagation delay threshold, and subsequently determining a reference TRP based on the RSRP value. Conversely, an RSRP threshold may also be utilized to determine a communication TRP, and then a reference TRP may be selected based on the propagation delay.

[0221] Figure 13 is a sequence diagram showing the case where the UE sends information about the determined communication TRP and reference TRP to all TRPs that have sent PRACH preambles.

[0222] Figure 13 shows the UE 1001 and four different TRPs 1011, 1012, 1013, and 1014 as entities performing the Figure 13 operation. In Figure 13 the UE 1001 and TRPs 1011, 1012, 1013, and 1014 use the same reference numerals as those described in Figures 10 to 12 . In other words, the configurations of the UE 1001 and TRPs 1011, 1012, 1013, and 1014 as entities performing the Figure 13 operation may be the same as those described in Figures 10 to 12 . Additionally, the UE 1001 and TRPs 1011, 1012, 1013, and 1014 as entities performing the Figure 13 operation may be in a state where the Figures 10 to 12 operation has been pre-executed. In the following description of the Figure 13 operation, for ease of description, it is assumed that the Figures 10 to 12 operation has been executed, or at least the Figure 12 operation has been completed.

[0223] As Figure 13As shown, the UE 1001 may be in a state where the communication TRP and the reference TRP have been determined based on the propagation delay and RSRP values of the PRACH preambles received from all the TRPs 1011, 1012, 1013, and 1014 and according to a specific criterion. Additionally, Figure 13 the process in Figure 13 may not correspond to the process of the number of TRPs through which the network set represented by the TRP communicates with the UE, but rather to the process where the UE itself selects the communication TRP and the reference TRP from the perspective of the UE and sends the information about the communication TRP and the reference TRP to all the TRPs 1011, 1012, 1013, and 1014 to which the PRACH preamble has been sent.

[0224] In step S1300, the UE 1001 may send the information about the communication TRP and the reference TRP determined by the UE 1001 to the TRP A 1011. Here, one of the uplink control information (UCI), UE assistance information, or SRB3 UE assistance information may be used to send the information about the communication TRP and the reference TRP. In another example, if an RRC message is defined to send the information about the communication TRP and the reference TRP, the information about the communication TRP and the reference TRP may be sent through the RRC message. If the UE 1001 receives a UE information request message requesting the information about the communication TRP and the reference TRP from the base station in the process described previously Figure 11 then the UE 1001 may send the obtained information about the communication TRP and the reference TRP through a UE information response message in response to the UE information request message.

[0225] In another example, if the base station to which the TRP A 1011 is connected is not in an RRC connection state with the UE 1001, the UE 1001 may perform a secondary node addition process with the TRP A 1011 and then send the information about the communication TRP and the reference TRP determined by the UE 1001 through the SRB3 UE assistance information. In this case, if the SRB3 signaling is defined to send the information about the communication TRP and the reference TRP, the information may be sent through the SRB3 signaling.

[0226] In step S1302, the UE 1001 may send the information about the communication TRP and the reference TRP determined by the UE 1001 to the TRP B 1012. In this case, one of the methods described in step S1300 may be used to send the information about the communication TRP and the reference TRP.

[0227] In step S1304, UE 1001 may send information about the communication TRP and the reference TRP determined by UE 1001 to TRP C 1013. Similarly, one of the methods described in step S1300 may be used to send information about the communication TRP and the reference TRP.

[0228] In the same way, in step S1306, UE 1001 may send information about the communication TRP and the reference TRP determined by UE 1001 to TRP D 1014. Here, one of the methods described in step S1300 may be used to send information about the communication TRP and the reference TRP.

[0229] An example of the information sent by UE 1001 to all TRPs 1011, 1012, 1013, and 1014 based on the above process may be provided as shown in Table 5 below.

[0230] [Table 5]

[0231]

[0232] As shown in Table 5, UE 1001 may send information about the TRP ID of the communication TRP and the ID of the reference TRP to all TRPs 1011, 1012, 1013, and 1014.

[0233] On the other hand, in the Figure 13 operation shown, TRP D 1014 may be a TRP that is not configured as the communication TRP in Figure 12 . In this case, UE 1001 may not perform step S1306. In other words, UE 1001 may not send information about the communication TRP and the reference TRP to TRP D 1014.

[0234] In another example, instead of performing step S1306, UE 1001 may notify TRP D 1014 that TRP D 1014 is not a communication TRP.

[0235] When each of TRPs 1011, 1012, 1013, and 1014 receives information about the communication TRP and the reference TRP from UE 1001, each of TRPs 1011, 1012, 1013, and 1014 may provide the corresponding information to the base station to which it is connected. Additionally, in Figure 13Operations performed at a higher layer in the processes described in , such as operations performed at the MAC layer or the RRC layer, can all be performed under the control of the base station. Correspondingly, the TRPs 1011, 1012, 1013, and 1014 can perform operations of transmitting or receiving corresponding information under the control of the base station. Additionally, when necessary, the control entity for all or part of the operations performed at the physical layer can also be the base station connected to the corresponding TRPs 1011, 1012, 1013, and 1014.

[0236] Figures 10 to 13 The processes described in can correspond to the process in which the UE 1001 selects, from the perspective of the UE, the TRP with which the UE 1001 intends to communicate. Through these processes, in a 5G NR MTRP environment, it is possible to prevent limitations on the number of TRPs communicating with the UE that may occur when selecting a communication TRP based on the CP of the parameter set allocated to the UE from the perspective of the TRP. In other words, according to an exemplary embodiment of the present invention, the UE 1001 can determine the communication TRP and the reference TRP based on the propagation delay threshold of the UE 1001 and the propagation delay values received from the corresponding TRPs. According to another exemplary embodiment of the present invention, the UE 1001 can determine the communication TRP and the reference TRP based on the RSRP values received from the corresponding TRPs in response to the PRACH preamble transmitted by the UE 1001 and a predetermined RSRP threshold.

[0237] Figures 10 to 13 The processes described in can be used as prerequisite processes for the reference TRP to allocate parameter sets, SCSs, CPs, and TA values to other communication TRPs, thereby ensuring that the TRPs are allocated common parameter sets, SCSs, and CPs.

[0238] In addition, the present invention considers both the in-cell environment where each TRP is connected to the same base station and the inter-cell environment where each TRP is connected to different base stations. Furthermore, according to the present invention, TA configuration can be supported for the RACH process only in the in-cell environment using the methods described in the present invention. However, in a general RRC connected state, regardless of the network structure, these methods can support both the in-cell and inter-cell environments.

[0239] [B] Resource Allocation Method Based on Propagation Delay in an MTRP Environment

[0240] In an MTRP environment, due to differences in propagation delays between multiple TRPs, the number of TRPs with which a single UE can communicate may be limited. The process of selecting a reference TRP considering the propagation delays between the UE and two or more TRPs has been described above. Hereinafter, a method for allocating parameter sets, SCSs, and CPs when considering the propagation delays between the reference TRP, the communication TRP, and the UE will be described.

[0241] According to the current NR technical specifications, a UE can support only one parameter set, that is, a single SCS. Therefore, in order to allocate a common parameter set, SCS, and CP to all TRPs, the reference TRP can send the necessary information to allow the same parameter set, SCS, CP, and TA values as the reference TRP to be allocated to other communicating TRPs. Conversely, according to Figures 10 to 13 the present invention described in

[0242] In the exemplary embodiments described below, each TRP can obtain information about the reference TRP and the communicating TRPs through the process described in Part [A]. Therefore, a method and process will be described in which, based on or independent of the process described in Part [A], the parameter set, SCS, CP, and TA values for the reference TRP are determined according to specific rules for communicating with the UE, the parameter set, SCS, CP, and TA values for other communicating TRPs are determined, and the determined values are sent to other TRPs and / or the UE.

[0243] Specifically, the present invention described below describes the situation in an MTRP environment where information exchange between TRPs occurs via the backhaul formed between the TRPs or via the backhaul formed between the base stations connected to the TRPs. In addition, the situation where there is no backhaul between TRPs or the case where information transmission via the backhaul is not feasible due to various reasons is also considered.

[0244] Figure 14 is a sequence diagram showing the case where the UE sends the identifiers and propagation delay values of communicating TRPs other than the reference TRP to the reference TRP.

[0245] Figure 14 shows the UE 1001 and four different TRPs 1011, 1012, 1013, and 1014 as entities performing the Figure 14 operations. In Figure 14 , the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 use the same reference numerals as those described in Figures 10 to 12 . In other words, the configuration of the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 as entities performing the Figure 14 operations can be the same as the configuration described in Figures 10 to 13 . In addition, the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 as entities performing the Figure 14 operations can be in a state where Figures 10 to 13The status of the operation. In Figure 14 In the following description of the operation of Figures 10 to 13 , for ease of description, it is assumed that the operation of Figure 13 has been performed, or at least

[0246] In step S1400, the UE 1001 may send information about the IDs of communication TRPs other than the reference TRP and the propagation delay between the UE 1001 and the communication TRPs other than the reference TRP to the reference TRP which is the TRP A1011. In this case, based on the above description, the communication TRPs other than the reference TRP may be the TRP B 1012 and the TRP C 1013. Accordingly, in step S1400, the UE 1001 may send the TRP ID_B and the PD_B to the TRP A 1011, where the TRP ID_B is an identifier indicating the TRP B 1012, and the PD_B is the propagation delay between the TRP B 1012 and the UE 1001. Additionally, through the same message or a different message, the UE 1001 may send the TRP ID_C and the PD_C to the TRP A 1011, where the TRP ID_C is an identifier indicating the TRP C 1013, and the PD_C is the propagation delay between the TRP C 1013 and the UE 1001.

[0247] The reason why the message sent by the UE 1001 to the reference TRP (TRP A 1011) in step S1400 includes information about only two TRPs is based on the previously described method. In other words, this is because in Figure 12 the process described in

[0248] the TRP C has not been configured as a communication TRP. If the TRP C is a communication TRP, the UE 1001 may send the information of the TRP C to the reference TRP together or separately through another message. In other words, if the number of communication TRPs other than the reference TRP is one, the UE 1001 may send the information of only one TRP, and if the number of communication TRPs is two or more, the UE 1001 may send the information of all communication TRPs to the reference TRP. Figure 14 When the UE and the base station (TRP A 1011) connected to the reference TRP are in the RRC connected state in

[0249] [Table 6]

[0250]

[0251] If the base station sends a UE information request message before the Figure 14 process, indicating that UE 1001 reports information on the TRP ID and propagation delay of communication TRPs other than the reference TRP, then UE 1001 may send, in response to the UE information request message, information on the TRP ID and propagation delay of communication TRPs other than the reference TRP through a UE information response message.

[0252] If the base station to which UE 1001 is connected to the reference TRP (TRP A 1011) is not in the RRC connected state, then UE 1001 may perform a secondary node addition process with the TRP, and then send information on the TRP ID and propagation delay of communication TRPs other than the reference TRP through SRB3 UE assistance information or newly defined SRB3 signaling.

[0253] If the base station to which UE 1001 is connected to the reference TRP (TRP A 1011) is not in the RRC connected state, then UE1001 may perform a secondary node addition process with the TRP, and then send information on the TRP ID and propagation delay of communication TRPs other than the reference TRP through SRB3 UE assistance information or a newly defined SRB3 signaling message.

[0254] On the other hand, operations performed at a higher layer in the Figure 14 process described, such as operations performed at the MAC layer or the RRC layer, may all be performed under the control of the base station. Accordingly, the reference TRP (TRP A 1011) may provide the received information to the base station or process the information under the control of the base station.

[0255] Figure 15 is a sequence diagram showing the case where the reference TRP determines information on resources to be used between the reference TRP and the UE, and information on resources to be used between communication TRPs other than the reference TRP and the UE.

[0256] Figure 15 shows UE 1001 and four different TRPs 1011, 1012, 1013, and 1014 as entities performing the Figure 15 operations. In Figure 15 , UE 1001 and TRPs 1011, 1012, 1013, and 1014 use the same reference numerals as those described in Figures 10 to 14 . In other words, as entities performing the Figure 15The configuration of the operating entities of UE 1001 and TRPs 1011, 1012, 1013 and 1014 can be Figures 10 to 14 In addition, as an implementation Figure 15 The UE 1001 and TRPs 1011, 1012, 1013 and 1014 of the entity of the operation may be in a state where the operation has been pre-executed. Figures 10 to 14 The status of the operation. Figure 15 In the following description of the operation, for ease of description, it is assumed that Figures 10 to 14 However, even if only some of the aforementioned operations are performed, Figure 15 For example, when only the process for acquiring the propagation delay with the UE by reference to the TRP is performed, or when the reference TRP has acquired both the information about the propagation delay between the reference TRP and the UE and the information about the propagation delay between the communication TRP other than the reference TRP and the UE, it is possible to apply Figure 15 .

[0257] like Figure 15 As shown, at step S1500, the reference TRP (TRP A 1011) can determine the maximum propagation delay and the minimum propagation delay using the propagation delays of the communication TRPs (which are TRP A 1011, TRP B 1012, and TRP C 1013). Then, TRP A 1011 can calculate the difference between the maximum propagation delay and the minimum propagation delay. Using the calculated difference, TRP A 1011 can allocate a CP to be used by the communication TRP, and allocate a parameter set and SCS corresponding to the CP. Then, TRP A 1011 can determine the TA value for UE 1001 using the minimum propagation delay value.

[0258] To describe this in more detail, it may be assumed that the propagation delay PD_A between TRP A 1011 and UE 1001, the propagation delay PD_B between TRP B 1012 and UE 1001, and the propagation delay PD_C between TRP C 1013 and UE 1001 have the following relationship.

[0259] Assumption: PD_A <PD_B<PD_C

[0260] When determining CP, TRP A 1011 as a reference TRP can ensure that the CP length CP_μ is longer than the difference between PD_C and PD_A so that ISI caused by propagation delay does not occur at any communication TRP. This can be expressed mathematically as shown in the following equation.

[0261] [Equation 1]

[0262] CPμ ≥ PD_C - PD_A

[0263] Based on the determined CP length CP_μ as described above, a parameter set (μ), an SCS value (SCS_μ), and a TA value can be allocated such that the TA value corresponds to the same TA_μ as PD_A.

[0264] If there are two or more CPs that satisfy the difference between the maximum propagation delay and the minimum propagation delay, the reference TRP (TRP A 1011) can allocate the parameter set, SCS, and CP values among the two or more CPs by considering other conditions such as the latency requirements of the UE 1011 and the RSRP.

[0265] For example, the parameter set, SCS, and CP can be allocated based on the latency requirements. If the latency requirements for the service provided to the UE 1001 are higher, a parameter set with a wider SCS and CP can be allocated to allocate a wider frequency band.

[0266] As another example, the parameter set, SCS, and CP values can be allocated based on the RSRP. If the RSRP of the signal to be sent to the UE 1001 is low, a lower frequency band needs to be allocated to reduce the signal path loss, and a parameter set corresponding to the lower frequency band, as well as the corresponding SCS and CP, can be allocated.

[0267] Based on the above method, the information allocated by the reference TRP (TRP A 1011) for communication with the UE 1001 can be as exemplified in Table 7 below.

[0268] [Table 7]

[0269]

[0270] Figure 15 The resource allocation operation described in can be interpreted as a process of allocating resources by considering the propagation delays of all TRPs communicating with the UE 1001 in addition to the reference TRP to solve the problems in traditional 5G NR, where the number of TRPs with which the UE 1001 can communicate is limited due to the differences in the propagation delays between TRPs.

[0271] According to the Figure 15 process as described above, the parameter set, SCS, CP values, and TA values allocated by the reference TRP (TRP A 1011) for the communication TRPs 1011, 1012, and 1013 can be used by the corresponding communication TRPs 1012 and 1013 to communicate with the UE 1001 in subsequent processes. A more detailed description of this will be provided with reference to the following drawings.

[0272] In addition, the exemplary embodiments of the present invention as described above have been considered in an environment with almost no delay spread in anticipation of the future 6G environment. However, in an environment with significant multipath effects, the CP can be additionally allocated based on the information about the delay spread transmitted during the process of Figure 11 to utilize the propagation delay and delay spread of the corresponding TRP and prevent the occurrence of ISI.

[0273] On the other hand, operations performed at a higher layer during the process described in Figure 15 , such as operations performed at the MAC layer or RRC layer, can all be performed under the control of the base station. Accordingly, the reference TRP (TRP A 1011) can send the corresponding information to the base station under the control of the base station. In addition, the operation of step S1500 can actually be performed at the base station connected to TRP A 1011. It should be noted that, for ease of description, Figure 15 an example where TRP A 1011 performs these operations is provided.

[0274] Figure 16 is a sequence diagram showing a case where the reference TRP sends information about the allocated resources to other communication TRPs and UEs.

[0275] Figure 16 shows the UE 1001 and four different TRPs 1011, 1012, 1013, and 1014 as entities performing the operations of Figure 16 . In Figure 16 , the UE 1001 and TRPs 1011, 1012, 1013, and 1014 use the same reference numerals as those described in Figures 10 to 15 . In other words, the configurations of the UE 1001 and TRPs 1011, 1012, 1013, and 1014 as entities performing the operations of Figure 16 can have the same configurations as those described in Figures 10 to 15 . In addition, the UE 1001 and TRPs 1011, 1012, 1013, and 1014 as entities performing the operations of Figure 16 can be in a state where the operations of Figures 10 to 15 have been performed. In the following description of the operations of Figure 16 , for ease of description, the description will be provided assuming that the operations of Figures 10 to 15 have been performed. However, when only some of the previously described operations have been performed, the operations of Figure 16 can also be performed. For example, when only the operations of Figure 15 and their necessary processes have been performed, the operations of Figure 16 can be performed. In addition, in the description of Figure 16When it is assumed that there is a backhaul between TRP A 1011 and TRP B 1012, and there is also a backhaul between TRP A 1011 and TRP C 1013.

[0276] In step S1600, the reference TRP (TRP A 1011) can send the TA value TA_μ to the UE 1001. In this case, the TA value can be the TA value determined based on Figure 15 the description. As another example, the TA value can be determined by TRP A 1011 itself without Figure 15 the process, or by another method independent of Figure 15 . As yet another example, the TA value can be determined by the base station connected to the reference TRP (TRP A 1011). Accordingly, in step S1600, the UE 1001 can receive the TA value TA_μ from TRP A 1011. When receiving the TA value, the UE 1001 can determine the UL transmission timing based on the TA value, as described in Figure 9a and Figure 9b .

[0277] If the UE 1001 is in the RRC connected state with the base station connected to the reference TRP (TRP A 1011), then in step S1600, TRP A 1011 can send the information about TA to the UE 1001 through SIB, DCI or MAC-CE. As another example, if a new RRC signaling message is defined for sending the information about TA, or if a new SRB3 signaling message is defined, then the information about TA can be sent through the new RRC signaling message or the new SRB3 signaling message.

[0278] If the UE 1001 is not in the RRC connected state with the base station connected to the reference TRP (TRP A 1011), then TRPA1011 can send the information about TA through SIB, DCI or MAC-CE, or if a new SRB3 signaling message is defined for sending the information about TA, then the information about TA can be sent to the UE 1001 through the new SRB signaling message.

[0279] In step S1602, the reference TRP (TRP A 1011) can send the parameter set, SCS and CP to be used by the communication TRP (TRP B1012) to the TRP B 1012. In this case, the reference TRP (TRP A 1011) can configure and send the identifier (TRP ID_B) of the communication TRP (TRP B 1012) and the information. In addition, the information about the parameter set, SCS and CP can be sent via the backhaul between TRP A 1011 and TRP B 1012.

[0280] In step S1604, the reference TRP (TRP A 1011) may send a parameter set, SCS, and CP to be used by another communication TRP (TRP C 1013) to the TRP C 1013. In this case, the reference TRP (TRP A 1011) may configure and send the identifier (TRP ID_C) of the communication TRP (TRP C 1013) and information. Additionally, information regarding the parameter set, SCS, and CP may be sent via the backhaul between the TRP A 1011 and the TRP C 1013.

[0281] Here, the information regarding the parameter set, SCS, and CP sent from the TRP A 1011 to the TRP B 1012 in step S1602 and the information regarding the parameter set, SCS, and CP sent from the TRP A 1011 to the TRP C 1013 in step S1604 may be Figure 15 the same as the information described in. In other words, the information sent from the TRP A 1011 to the TRP B 1012 in step S1602 and the information sent from the TRP A 1011 to the TRP C 1013 in step S1604 may be exactly the same. Specifically, the parameter set μ, SCS value SCS_μ, and CP value CP_μ sent in steps S1602 and S1604 may correspond to the example values in Table 7 above.

[0282] Accordingly, in step S1602, the TRP B 1012 may receive the parameter set μ, SCS value SCS_μ, and CP value CP_μ from the TRP A 1011, and in step S1604, the TRP C 1013 may receive the same values from the TRP A 1011. Then, when communicating with the UE1001, the TRP B 1012 and the TRP C 1013 may utilize the values received from the reference TRP (TRP A 1011) to allocate necessary resources for communication.

[0283] The information sent from the TRP A 1011 to the UE 1001 in step S1600 and the information sent from the TRP A 1011 in steps S1602 and S1604 may be exemplified as shown in Table 8 below.

[0284] [Table 8]

[0285]

[0286] On the other hand, in Figure 16Operations performed at higher layers in the processes described in, such as operations performed at the MAC layer or the RRC layer, can all be performed under the control of the base station. Accordingly, transmission control with reference to the TRP (TRP A 1011) can be performed by the base station connected to TRP A 1011. In addition, the communication TRPs 1012 and 1013 that receive information from TRP A 1011 can provide the received information to the corresponding base stations connected to the TRPs. If a specific TRP is connected to the same base station, the base station can independently process the information even if TRP A 1011 does not send information to the corresponding TRP.

[0287] Figure 17 is a timing diagram showing a case where a reference TRP transmits information about resources to be used for communication with a UE to other communication TRPs via the UE.

[0288] Figure 17 shows the UE 1001 and four different TRPs 1011, 1012, 1013, and 1014 as entities that perform the Figure 17 operations. In Figure 17 , the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 use the same reference numerals as those described in Figures 10 to 16 . In other words, the configurations of the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 as entities that perform the Figure 17 operations can have the same configurations as those described in Figures 10 to 16 . In addition, the UE 1001 and the TRPs 1011, 1012, 1013, and 1014 as entities that perform the Figure 17 operations can be in a state where the Figures 10 to 15 operations have been performed. In the following description of the Figure 17 operations, for ease of description, the description will be provided assuming that the Figures 10 to 15 operations have been performed. However, when only some of the previously described operations have been performed, the Figure 17 operations can also be performed. For example, when only the Figure 15 operations and their necessary processes have been performed, the Figure 17 operations can be performed.

[0289] On the other hand, different from Figure 16 , Figure 17 assumes an environment where there is no backhaul between TRP A 1011 and TRP B 1012, and no backhaul between TRP A 1011 and TRP C 1013. In addition, the following Figure 17The operations can also be applied to the cases where there is a backhaul between TRP A 1011 and TRP B 1012 but it cannot be used, and where there is a backhaul between TRP A 1011 and TRP C 1013 but it cannot be used. Here, the backhaul can include not only the backhaul between TRPs but also the backhaul between a TRP and the connected base station.

[0290] In step S1700, the reference TRP (TRP A 1011) can send information about the resources to be used for the communication between UE 1001 and other communication TRPs (TRP B 1012 and TRP C 1013) (including the parameter set, SCS, and CP), and the TA value TA_μ to be used by UE 1001. In this case, the parameter set, SCS, CP, and TA value to be used by UE 1001 can be determined based on Figure 15 the description.

[0291] On the other hand, the TA value can be determined by the reference TRP (TRP A 1011) itself without performing Figure 15 the process, or by another method independent of Figure 15 . As another example, the TA value can be determined by the base station connected to the reference TRP (TRP A 1011). Accordingly, in step S1600, UE 1001 can receive information about the parameter set, SCS, and CP, and the TA value TA_μ from TRP A 1001. When receiving the TA value, UE 1001 can determine the UL transmission timing based on the TA value, as described in Figure 9a and Figure 9b .

[0292] If UE 1001 is in the RRC connected state with the base station connected to the reference TRP (TRP A 1011), then in step S1600, TRP A 1011 can send information about the parameter set, SCS, and CP, and TA information to UE 1001 through SIB, DCI, or MAC-CE. As another example, if a new RRC signaling message is defined for sending TA information, or if a new SRB3 signaling message is defined for sending TA information, then the TA information can be sent through the new RRC signaling message or the new SRB3 signaling message.

[0293] If UE 1001 is not in the RRC connected state with the base station connected to the reference TRP (TRP A 1011), then TRP A 1011 can send TA information through SIB, DCI, or MAC-CE, or if a new SRB3 signaling message is defined for sending TA information, then the TA information can be sent to UE 1001 through the new SRB signaling message.

[0294] In step S1702, the UE 1001 may send information about the parameter set, SCS, and CP to be used by another communication TRP (TRP B 1012). In this case, the information about the parameter set, SCS, and CP may be the information sent from TRP A 1011 to the UE 1001 in step S1700. Additionally, the UE 1001 may send the identifier of TRP B 1012, TRP ID_B, along with the information about the parameter set, SCS, and CP to indicate the recipient of the information. Accordingly, TRP B 1012 may receive the information about the parameter set, SCS, and CP from the UE 1001. TRP B 1012 may use the received information about the parameter set, SCS, and CP for resource allocation for communicating with the UE 1001.

[0295] In step S1704, the UE 1001 may send information about the parameter set, SCS, and CP to be used by another communication TRP (TRP C 1013). In this case, the information about the parameter set, SCS, and CP may be the information sent from TRP A 1011 to the UE 1001 in step S1700. Additionally, the UE 1001 may send the identifier of TRP C 1013, TRP ID_C, along with the information about the parameter set, SCS, and CP to indicate the recipient of the information. Accordingly, in step S1704, TRP C 1013 may receive the information about the parameter set, SCS, and CP from the UE 1001. TRP C 1013 may use the received information about the parameter set, SCS, and CP for resource allocation for communicating with the UE 1001.

[0296] The operations in steps S1702 and S1704 above may correspond to Figure 16 Compared with the operation where the reference TRP (TRP A 1011) sends information about the parameter set, SCS, and CP to be used for communicating with the UE 1001 to other communication TRPs (TRP B 1012 and TRP C 1013) via the backhaul.

[0297] When the UE 1001 sends information about the parameter set, SCS, and CP received from the TRP A 1011, together with their TRP IDs, to the TRP B 1012 and the TRP C 1013, the transmission scheme may vary according to the RRC connection status between each of the base stations connected to the TRP B 1012 and the TRP C 1013 and the UE 1001. If the base station connected to the communicating TRP is in the RRC connected state with the UE 1001, the UE 1001 may use one of UCI, UE capability information, or SRB3 UE assistance information in step S1702 and / or step S1704 to send information about the parameter set, SCS, and CP. As another example, if there is a newly defined RRC signaling message or a newly defined SRB3 signaling message that allows the UE to be able to send information about the parameter set, SCS, and CP to the TRP, and if the base station connected to the communicating TRP is in the RRC connected state with the UE 1001, the UE 1001 may use the newly defined RRC signaling message or the newly defined SRB3 signaling message to send information about the parameter set, SCS, and CP to the communicating TRP.

[0298] On the other hand, if the base station connected to the communicating TRP is not in the RRC connected state with the UE 1001, the UE 1001 may send information about the parameter set, SCS, and CP to the communicating TRP in step S1702 and / or step S1704 via the SRB3 UE assistance information or the newly defined SRB3 signaling message for sending information about the parameter set, SCS, and CP.

[0299] As described above, the transmission of the information according to the present invention may be exemplified in Table 9 below.

[0300] [Table 9]

[0301]

[0302] In addition, in Figure 17 the example, the communicating TRPs 1011, 1012, and 1013 may all be TRPs connected to different base stations. If the base station connected to the TRP B 1012 is the same as the base station connected to the TRP A 1011, the base station may not need to send information to the TRP B 1012. Accordingly, the information for transmission in "TRP A→UE→TRP B" exemplified in Table 9 may not be provided to the UE 1001. Similarly, if the base station connected to the TRP C 1013 is also the same as the base station connected to the TRP A 1011, the information for transmission in "TRP A→UE→TRP C" may not be provided to the UE 1001 either. As Figure 17In the example, both TRP B 1012 and TRP C 1013 can be TRPs connected to a base station different from TRP A 1011.

[0303] On the other hand, the control of the operation of TRP A 1011 to send information in step S1700 can actually be executed by the base station connected to TRP A 1011. Additionally, TRP B 1012 and TRP C 1013 can provide the received information to the corresponding base stations to which they are connected. By doing so, the base stations connected to the corresponding TRPs can perform the necessary operations or controls accordingly.

[0304] In addition, the above Figures 10 to 17 process can be combined as a whole, partially combined, or combined with other exemplary embodiments not described in the present invention for application.

[0305] Figure 18 is a conceptual diagram showing the operation flow of the overall combination of exemplary embodiments based on the present invention.

[0306] As Figure 18 shown, in step S1810, each of all TRPs can measure the propagation delay and RSRP of the preamble sent by the UE, and provide the measured values to the UE. In other words, the UE can send a UE PRACH preamble to each of all TRPs capable of receiving SSB, and each of all TRPs can receive the UE PRACH preamble sent by the UE and measure the propagation delay and RSRP of the preamble. The measurement operations so far can follow the same process as the Figure 10 exemplary embodiment described in. Accordingly, at least a part of the operations described in Figure 10 can be used for the specific operations related to the measurement process in step S1810.

[0307] Additionally, in step S1810, each of all TRPs that have received the UE PRACH preamble can send the measured propagation delay and RSRP values of the preamble together with its TRP ID to the UE. The operation of providing the measured information to the UE can correspond to the Figure 11 exemplary embodiment described in. Accordingly, at least a part of the operations described in Figure 13 can be used for the specific operations of all TRPs to send the measured information to the UE in step S1810.

[0308] Accordingly, in step S1810, the UE can receive information on the propagation delay value and RSRP value of the preamble from all TRPs.

[0309] In step S1820, the UE may configure (or determine) the communication TRP and the reference TRP based on the propagation delay values and RSRP values received from all TRPs. The operation in step S1820 may correspond to Figure 12 the exemplary implementation described in Figure 13 and at least a part of the operations described in

[0310] In step S1830, the UE may deliver information about the communication TRP and the reference TRP to all TRPs. The operation in step S1830 may correspond to Figure 13 the exemplary implementation described in Figure 13 and at least a part of the operations described in

[0311] In step S1840, the UE may send information about the propagation delay of other communication TRPs to the reference TRP. Accordingly, at least a part of the operations described in Figure 14 may be used for the specific operation in step S1840.

[0312] In step S1850, the reference TRP may determine the parameter set, SCS, and CP to be used by the reference TRP and other communication TRPs. Additionally, the reference TRP may determine the TA value to be used for communication with the UE. Accordingly, at least a part of the operations described in Figure 15 may be used for the specific operation in step S1850.

[0313] Step S1860 may correspond to the case where there is a backhaul between TRPs. Accordingly, in step S1860, the reference TRP may deliver information about the determined parameter set, SCS, and CP to other communication TRPs via the backhaul. Additionally, the reference TRP may send information about the determined TA value to the UE. At least a part of the operations described in Figure 16 may be used for the specific operation in step S1860.

[0314] Step S1870 may correspond to the case where there is no backhaul between TRPs, or the backhaul cannot be used even if there is a backhaul. Accordingly, in step S1870, the reference TRP may instruct the UE to deliver information about the parameter set, SCS, and CP to other communication TRPs via the UE. Additionally, the reference TRP may deliver information about the determined TA value to the UE. At least a part of the operations described in Figure 17 may be used for the specific operation in step S1870.

[0315] On the other hand, in Figures 10 to 18In an exemplary embodiment, a set of parameters for resource allocation, and the determination of the SCS, CP, and TA values have been described under the assumption that the determination is performed by the TRP. However, this determination may also be performed by the base station, and the determined information may then be delivered to each TRP. When the base station determines the parameter set, SCS, CP, and TA values, an additional process may be performed, in which the TRP reports the received measurement values to the base station and receives the determined values from the base station.

[0316] Figure 19 is a sequence diagram showing the case of determining resources for communicating with a UE using all exemplary embodiments in the case where there is a backhaul between TRPs.

[0317] In Figure 19 , UE 1001 and four different TRPs 1011, 1012, 1013, and 1014 are exemplified as entities performing operations, and since all these entities are described in the present invention, they may perform the same configurations and operations as previously described.

[0318] In steps S1900a and S1900b, UE 1001 may send a UE PRACH preamble to each of all TRPs 1011 to 1014 capable of receiving an SSB. Steps S1900a and S1900b may correspond to the process in which UE 1001 sends a UE PRACH preamble to each of all TRPs 1011 to 1014, as Figure 10 described.

[0319] In steps S1902a and S1902b, each of all TRPs 1011 to 1014 that has received the UE PRACH preamble may send its identifier, and the RSRP value and propagation delay value of the received preamble, to UE 1001. Steps S1902a and S1902b may correspond to the process in which each of all TRPs 1011 to 1014 sends the measured information to UE 1001, as Figure 11 described.

[0320] In step S1904, UE 1001 may determine a communication TRP and a reference TRP based on the received propagation delay value and RSRP value. Step S1904 may correspond to the process Figure 12 described, in which the communication TRP is determined based on the received propagation delay value and the reference TRP is determined among the communication TRPs, or the communication TRP is determined based on the received RSRP value and the reference TRP is determined among the communication TRPs.

[0321] In steps S1906a and S1906b, the UE 1001 may notify all the TRPs 1011 to 1014 of the communication TRP and the reference TRP. If a specific TRP (e.g., TRP D 1014) is not a communication TRP, the specific TRP may be notified that it is not a communication TRP, or it may be configured not to notify the TRPs that are not communication TRPs of the information about the communication TRP and the reference TRP. Steps S1906a and S1906b may correspond to Figure 13 the same operations described in

[0322] In step S1908, the UE 1001 may send the TRP IDs of TRP B 1012 and TRP C 1013, which are communication TRPs but not reference TRPs, together with the information about the propagation delay between each TRP and the UE 1001, to the reference TRP 1011. Step S1908 may correspond to the same operations as described in Figure 14

[0323] In step S1910, the reference TRP (TRP A 1011) may determine the parameter set, SCS, and CP, and determine the TA value for the UE 1001. The operations in step S1910 may correspond to the same operations as described in Figure 15

[0324] In step S1912, the reference TRP (TRP A 1011) may deliver the TA value to the UE 1001. Then, in step S1914, the reference TRP (TRP A 1011) may send the information about the parameter set, SCS, and CP to TRP B 1012 and TRP C 1013, which are not reference TRPs, via the backhaul. Steps S1912 and S1914 may correspond to the same operations as described in Figure 16

[0325] Figure 20 is a sequence diagram showing the case of determining the resources for communicating with the UE using all the exemplary embodiments in an environment where there is no backhaul between the TRPs.

[0326] In Figure 20 , the UE 1001 and four different TRPs 1011, 1012, 1013, and 1014 are exemplified as the entities performing operations, and since all these entities are described in the present invention, they may perform the same configurations and operations as previously described.

[0327] Steps S2000a and S2000b may correspond to Figure 19 steps S1900a and S1900b described in Figure 19 ​​​The steps S1902a and S1902b described in Figure 19 The step S1904 described in Figure 19 The steps S1906a and S1906b described in Figure 19 The step S1908 described in Figure 19 The step S1910 described in

[0328] In step S2012, since there is no backhaul link between the reference TRP (TRP A 1011) and other communication TRPs 1012 and 1013, the reference TRP may send information about the parameter set, SCS, and CP to the UE 1001 for transmission to other communication TRPs. In this case, TRP A 1011 may instruct the UE 1001 to send information to other communication TRPs. Additionally, TRP A1011 may send information about the TA value to be used by the UE 1001.

[0329] In step S2014, the UE 1001 may send the information about the parameter set, SCS, and CP received from the reference TRP (TRP A1011) to TRP B 1012 and TRP C 1013 which are not the reference TRP. Steps S2012 and S2014 may correspond to the same operation as described in Figure 17

[0330] On the other hand, the method described in Figures 10 to 20 may correspond to the case of using the same frequency band, i.e., the control resource sets (CORESETs) used by all TRPs are the same. If different TRPs use different CORESETs, different TA values may be used for each TRP group or for each TRP individually.

[0331] The operations of the method according to an exemplary embodiment of the present invention may be implemented as a computer-readable program or code in a computer-readable recording medium. The computer-readable recording medium may include all types of recording devices storing data readable by a computer system. In addition, the computer-readable recording medium may store and execute programs or codes, which may be distributed in computer systems connected through a network and read by a computer in a distributed manner.

[0332] ​A computer-readable recording medium may include a hardware device specifically configured to store and execute program instructions, such as ROM, RAM, or flash memory. Program instructions may include not only machine language code created by a compiler, but also high-level language code executable by a computer using an interpreter.

[0333] Although some aspects of the present invention have been described in the context of an apparatus, these aspects may indicate corresponding descriptions according to the method, and a block or apparatus may correspond to a step or a feature of a step of the method. Similarly, aspects described in the context of a method may be represented as features of a corresponding block or item or a corresponding apparatus. Some or all steps of a method may be performed by (or using) a hardware device such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most important steps of a method may be performed by such a device.

[0334] In some exemplary embodiments, a programmable logic device such as a field-programmable gate array may be used to perform some or all of the functions of the methods described herein. In some exemplary embodiments, a field-programmable gate array may be operated with a microprocessor to perform one of the methods described herein. Generally, a method is preferably performed by a specific hardware device.

[0335] The description of the present invention is merely exemplary in nature, and thus variations that do not depart from the essence of the present invention are intended to be within the scope of the present invention. Such variations should not be regarded as departing from the spirit and scope of the present invention. Accordingly, those of ordinary skill in the art will understand that various changes in form and detail may be made without departing from the spirit and scope defined by the appended claims.

Claims

1. A method of a user equipment (UE), comprising: Sending a preamble signal to each of two or more transmit and receive points (TRPs); Receiving first information from each of the two or more TRPs, the first information including the propagation delay of the preamble signal and the received power (RP) value measured at each of the two or more TRPs; Determining a first communication group including the TRPs capable of communication based on the first information received from each of the two or more TRPs; Selecting a reference TRP within the first communication group; Sending the first information received from one or more TRPs other than the reference TRP among the TRPs capable of communication included in the first communication group to the reference TRP; And Receiving a timing advance (TA) value to be used for uplink communication with the TRPs capable of communication included in the first communication group from the reference TRP.

2. The method according to claim 1, wherein The first information received from each of the two or more TRPs further includes: the identifier (ID) of the TRP that sent the first information.

3. The method according to claim 1, further comprising: Sending second information to all the TRPs that have received the first information, the second information including information about the reference TRP and one or more TRPs included in the first communication group.

4. The method according to claim 1, wherein Each of the TRPs capable of communication included in the first communication group is a TRP having a propagation delay less than a preset threshold.

5. The method according to claim 4, wherein The preset threshold is determined based on the capability information of the UE.

6. The method according to claim 4, wherein, The reference TRP is the TRP having the highest RP value among the TRPs capable of communication within the first communication group.

7. The method according to claim 1, wherein Each of the TRPs capable of communication included in the first communication group is a TRP having an RP value equal to or greater than the preset threshold.

8. The method according to claim 7, wherein The reference TRP is the TRP having the minimum propagation delay among the TRPs capable of communication within the first communication group.

9. The method according to claim 1, further comprising: Receiving a command and third information indicating to send third information to at least one TRP included in the first communication group from the reference TRP; And Sending the third information to at least one TRP included in the first communication group, wherein the third information includes at least one of a TRP identifier, a parameter set, a subcarrier spacing (SCS), or a cyclic prefix (CP).

10. A method of a first base station, comprising: Receiving a preamble signal from a user equipment (UE) via a transmit and receive point (TRP) connected to the first base station; Measuring the propagation delay and received power (RP) of the preamble signal; Sending first information including the measured propagation delay and RP to the UE via the TRP; Receiving second information, the second information including information about at least one other TRP and information about the propagation delay and RP sent to the UE by the at least one other TRP; Determining a timing advance (TA) value and third information to be used for communication with the UE based on the first information and the second information corresponding to the at least one other TRP; And Sending the TA value to the UE via the TRP, The third information includes at least one of a parameter set, a subcarrier spacing (SCS), or a cyclic prefix (CP) to be used by at least one other TRP for communicating with the UE.

11. The method according to claim 10, further comprising: Receive, from the UE, information about a first communication group including at least one other TRP capable of communicating with the UE.

12. The method according to claim 11, further comprising: Send the third information to a TRP included in the first communication group or to a second base station connected to the TRP included in the first communication group.

13. The method according to claim 11, further comprising: Send the third information and first instruction information to the UE, wherein the first instruction information is information indicating to send the third information to a TRP included in the first communication group.

14. A user equipment (UE) includes at least one processor, wherein, The at least one processor causes the UE to perform: Send a preamble signal to each of two or more transmit and receive points (TRPs); Receive first information from each of the two or more TRPs, the first information including a propagation delay of the preamble signal and a received power (RP) value measured at each of the two or more TRPs; Based on the first information received from each of the two or more TRPs, determine a first communication group including TRPs capable of communicating; Select a reference TRP within the first communication group; Send the first information received from one or more TRPs other than the reference TRP among the TRPs capable of communicating included in the first communication group to the reference TRP; And Receive a timing advance (TA) value to be used for uplink communication with the TRPs capable of communicating included in the first communication group from the reference TRP.

15. The UE according to claim 14, wherein, The first information received from each of the two or more TRPs further includes an identifier (ID) of the TRP that sent the first information.

16. The UE according to claim 14, wherein, The at least one processor further causes the UE to perform: Send second information including information about the reference TRP and one or more TRPs included in the first communication group to all TRPs that have received the first information.

17. The UE according to claim 14, wherein, Each of the TRPs capable of communicating included in the first communication group is a TRP having a propagation delay less than a preset threshold.

18. The UE according to claim 17, wherein The preset threshold is determined based on the UE's capability information, and the reference TRP is the TRP having the highest RP value among the TRPs capable of communicating within the first communication group.

19. The UE according to claim 15, wherein Each of the TRPs capable of communicating included in the first communication group is a TRP having an RP value equal to or greater than the preset threshold, and the reference TRP is the TRP having the minimum propagation delay among the TRPs capable of communicating within the first communication group.

20. The UE according to claim 15, wherein The at least one processor causes the UE to perform: Receive a command indicating to send the third information to at least one TRP included in the first communication group and the third information from the reference TRP; and Send the third information to at least one TRP included in the first communication group, wherein the third information includes at least one of a TRP identifier, a parameter set, a subcarrier spacing (SCS), or a cyclic prefix (CP).

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