Beam management method and device based on multiple transmission and reception points

Abstract

A method of a terminal comprises the steps of: determining the type of the electromagnetic field between the terminal and a first transmission and reception point (TRP) group including a first TRP and one or more second TRP(s); after determining the type of the electromagnetic field, configuring a first beam pair set including transmission beams of the first TRP group and a first reception beam of the terminal; according to the type of the electromagnetic field, comparing the performance of the first reception beam measured on the basis of the first beam pair set with the performance of a second reception beam of the terminal measured on the basis of a second beam pair set including transmission beams of a second TRP group including the one or more second TRP(s) and the second reception beam; and determining whether the first TRP participates in multiple transmission and reception points (mTRP) transmission for the terminal on the basis of the comparison.

Description

Method and device for managing beams based on multiple transmission and reception points

[0001] The present disclosure relates to a beam management technology based on multiple transmission reception points transmission (mTRP), and more particularly, to an mTRP-based beam management technology according to the type of electromagnetic field to which a terminal belongs.

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

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

[0004] In NR communication networks, multiple transmission and reception points (mTRPs) can be proposed, in which a base station communicates with a single terminal using multiple transmission and reception points (TRPs). The electromagnetic field can be classified into a near-field or a far-field depending on the assumed type of radio wave. The physical characteristics of a beam suitable for the far-field (hereinafter referred to as a "far-field beam") and a beam suitable for the near-field (hereinafter referred to as a "near-field beam") can be different. In NR communication networks, the type of electromagnetic field formed between a terminal and TRPs participating in mTRP-based transmission can be considered a far-field.

[0005] In a 6G communication network, the size of an antenna array belonging to a base station may be larger than the size of an antenna array used in an NR communication network, and the frequency band used for communication may be higher than the bandwidth (e.g., FR (frequency range)2) used in the NR communication network. Therefore, among the TRPs participating in mTRP transmission in a 6G communication network, the type of electromagnetic field formed between some TRPs (hereinafter referred to as "first TRPs") and a terminal may be a near-field. In mTRP transmission, the first TRPs may use a near-field beam for communication with the terminal, and other TRPs may use a far-field beam. When different types of beams are used in mTRP transmission, the far-field beam and the near-field beam may interfere. Inter-beam interference may cause a degradation of communication performance. Therefore, when TRPs participating in mTRP transmission in a 6G communication network form different types of electromagnetic fields with a single terminal, a new beam management procedure may need to be defined.

[0006] The purpose of the present disclosure to solve the above problems is to provide a method and device for ~~~ in a communication system.

[0007] According to a first embodiment of the present disclosure for achieving the above object, a method of a terminal includes the steps of: determining a type of an electromagnetic field between a first TRP group including a first transmission and reception point (TRP) and one or more second TRP(s) and the terminal; setting a first beam pair set including transmission beams of the first TRP group and a first reception beam of the terminal after determining the type of the electromagnetic field; performing a comparison between the performance of the first reception beam measured based on the first beam pair set and the performance of the second reception beam measured based on a second beam pair set including transmission beams of a second TRP group including one or more second TRP(s) and a second reception beam of the terminal, according to the type of the electromagnetic field; and determining whether the first TRP participates in mTRP (multiple transmission and reception points) transmission for the terminal based on the comparison, wherein each of the second TRP group and the first TRP group is configured to set an mTRP for the terminal based on each of the second beam pair set and the first beam pair set. Perform the transmission.

[0008] The method of the terminal may further include, before determining the type of the electromagnetic field between the first TRP group and the terminal, a step of receiving first information for determining the type of the electromagnetic field between the first TRP and the terminal, and a step of determining the type of the electromagnetic field between the first TRP and the terminal based on the first information, wherein the first information may include at least one of information on a pattern of PT (phase tracking)-RS (reference signals) received from the first TRP, information on a time interval during which the PT-RSs are transmitted, information on a frequency band used for communication between the first TRP and the terminal, information on a maximum length of an antenna array belonging to the first TRP, information on a distance between the first TRP and the terminal, or an identifier of the first TRP.

[0009] The method of the terminal may further include, before determining the type of the electromagnetic field between the first TRP and the terminal, a step of receiving PT-RSs from the first TRP, and a step of determining a maximum phase difference between PT-RSs received by antenna elements belonging to the terminal based on the PT-RSs, and the type of the electromagnetic field between the first TRP and the terminal may be determined based on the maximum phase difference.

[0010] The method of the terminal may further include, before determining the type of electromagnetic field between the first TRP and the terminal, a step of determining a Rayleigh distance between the first TRP and the terminal based on at least one of the first information or information on a maximum length of an antenna array belonging to the terminal, and the type of the electromagnetic field between the first TRP and the terminal may be determined based on the Rayleigh distance.

[0011] The step of setting the first beam pair set may include the step of transmitting information on the type of an electromagnetic field between the first TRP and the terminal to the first TRP, the step of forming reception beams of the terminal for a transmission beam of the first TRP determined through beam sweeping of the first TRP in response to the information on the type of an electromagnetic field between the first TRP and the terminal, and the step of setting the first beam pair set including a beam pair composed of a reception beam determined based on RSRP values ​​of the reception beams among the reception beams and a transmission beam of the first TRP.

[0012] The step of setting the first beam pair set may include the step of transmitting information on the type of an electromagnetic field between the first TRP and the terminal to the first TRP, the step of forming reception beams of the terminal for transmission beams determined through joint beam adjustment of the first TRP group in response to the information on the type of an electromagnetic field between the first TRP and the terminal, and the step of setting the first beam pair set including a beam pair composed of the first reception beam determined based on RSRP values ​​of the reception beams among the reception beams and the transmission beam of each of the TRPs belonging to the first TRP group.

[0013] The method of the terminal may further include a step of terminating a beam management procedure with the first TRP group when it is determined that the first TRP participates in mTRP transmission for the terminal.

[0014] The method of the terminal may further include a step of transmitting a request to stop signal transmission to the first TRP when it is determined that the first TRP does not participate in mTRP transmission for the terminal.

[0015] The method of the terminal may further include a step of transmitting a transmission beam set recovery request signal to a coordinating TRP among the second TRP group when it is determined that the first TRP does not participate in mTRP transmission for the terminal, and the transmission beam set recovery request signal may be a signal requesting that the first transmission beam set of the second TRP group be changed to a second transmission beam set that was set before the first TRP participated in mTRP transmission.

[0016] The method of the terminal may further include a step of changing the first reception beam of the terminal to the second reception beam of the terminal set before the first TRP group performs mTRP transmission when it is determined that the first TRP does not participate in mTRP transmission for the terminal.

[0017] The method of the terminal may further include a step of performing measurement on at least one of an RSRP value of a combined beam in which beams received from the second TRP group are combined according to a set period based on an mTRP timer set in the terminal or a distance moved by the terminal during the period, and a step of transmitting a participation request message to a coordinating TRP among the second TRP group based on the measurement, wherein the participation request message may be a message requesting that the first TRP participate in mTRP transmission.

[0018] A method of a first transmission and reception point (TRP) according to a first embodiment of the present disclosure for achieving the above object includes the steps of transmitting first information for determining a type of an electromagnetic field between the first TRP and the terminal to a terminal, receiving information on a type of an electromagnetic field between the first TRP and the terminal determined based on the first information from the terminal, and performing beam sweeping using transmission beams that match the type of the electromagnetic field for the terminal in response to the information on the type of the electromagnetic field.

[0019] The method of the first TRP may further include a step of transmitting PT (phase tracking)-RS (reference signals) to the terminal after transmitting the first information, and the first information may include at least one of information on a pattern of the PT-RSs, information on a time period during which the PT-RSs are transmitted, information on a frequency band used for communication between the first TRP and the terminal, information on a maximum length of an antenna array belonging to the first TRP, or an identifier of the first TRP.

[0020] The method of the first TRP may further include a step of receiving RSRP values ​​of the transmission beams formed by the beam sweeping from the terminal, and a step of determining an optimal transmission beam for performing communication with the terminal based on the RSRP values.

[0021] The method of the first TRP may further include the steps of receiving a request to stop signal transmission from the terminal and stopping communication with the terminal in response to the request to stop signal transmission, receiving an mTRP transmission participation request signal from a coordinating TRP among a second TRP group that performs mTRP transmission for the terminal after stopping communication with the terminal, and performing mTRP transmission for the terminal in cooperation with the second TRP group in response to the mTRP transmission participation request signal.

[0022] According to a first embodiment of the present disclosure for achieving the above object, a terminal includes at least one processor, wherein the at least one processor causes the terminal to determine a type of an electromagnetic field between a first TRP group including a first transmission and reception point (TRP) and one or more second TRP(s) and the terminal, and after determining the type of the electromagnetic field, set a first beam pair set including transmission beams of the first TRP group and a first reception beam of the terminal, and perform a comparison between the performance of the first reception beam measured based on the first beam pair set and the performance of the second reception beam measured based on the second beam pair set including transmission beams of a second TRP group including one or more second TRP(s) and a second reception beam of the terminal, based on the type of the electromagnetic field, and determine whether the first TRP participates in mTRP (multiple transmission and reception points) transmission for the terminal based on the comparison, wherein each of the second TRP group and the first TRP group comprises the second beam pair set and mTRP transmission is performed for the terminal based on each of the first beam pair sets.

[0023] The at least one processor may further cause the terminal to receive first information for determining a type of an electromagnetic field between the first TRP and the terminal before determining a type of an electromagnetic field between the first TRP group and the terminal, and to determine a type of an electromagnetic field between the first TRP and the terminal based on the first information, wherein the first information may include at least one of information on a pattern of PT (phase tracking)-RS (reference signals) received from the first TRP, information on a time interval during which the PT-RSs are transmitted, information on a frequency band used for communication between the first TRP and the terminal, information on a maximum length of an antenna array belonging to the first TRP, information on a distance between the first TRP and the terminal, or an identifier of the first TRP.

[0024] The at least one processor may further cause the terminal to receive PT-RSs from the first TRP before determining the type of electromagnetic field between the first TRP and the terminal, and determine a maximum phase difference between PT-RSs received at antenna elements belonging to the terminal based on the PT-RSs, and the type of electromagnetic field between the first TRP and the terminal may be determined based on the maximum phase difference.

[0025] The at least one processor may further cause the terminal to determine a Rayleigh distance between the first TRP and the terminal based on at least one of the first information or information on a maximum length of an antenna array belonging to the terminal before determining a type of an electromagnetic field between the first TRP and the terminal, and the type of the electromagnetic field between the first TRP and the terminal may be determined based on the Rayleigh distance.

[0026] The at least one processor may cause the terminal, when setting the first beam pair set, to transmit information about a type of an electromagnetic field between the first TRP and the terminal to the first TRP, form reception beams of the terminal for a transmission beam of the first TRP determined through beam sweeping of the first TRP in response to the information about the type of an electromagnetic field between the first TRP and the terminal, and set a first beam pair set including a beam pair composed of a reception beam determined based on RSRP values ​​of the reception beams among the reception beams and a transmission beam of the first TRP.

[0027] The at least one processor may cause the terminal, when setting the first beam pair set, to transmit information on a type of an electromagnetic field between the first TRP and the terminal to the first TRP, form reception beams of the terminal for transmission beams determined through joint beam adjustment of the first TRP group in response to the information on the type of an electromagnetic field between the first TRP and the terminal, and set the first beam pair set including a beam pair composed of the first reception beam determined based on RSRP values ​​of the reception beams among the reception beams and the transmission beams of each of the TRPs belonging to the first TRP group.

[0028] If it is determined that the first TRP participates in mTRP transmission for the terminal, the at least one processor may further cause the terminal to terminate a beam management procedure with the first TRP group.

[0029] If it is determined that the first TRP does not participate in mTRP transmission to the terminal, the at least one processor may further cause the terminal to transmit a request to stop signal transmission to the first TRP.

[0030] According to the present disclosure, a terminal can determine the type of electromagnetic field between a candidate TRP (hereinafter referred to as a "first TRP") participating in a multiple transmission and reception points (mTRP) operation and the terminal. Based on the type of electromagnetic field between the first TRP and the terminal, the terminal can determine the type of electromagnetic field between the TRPs (hereinafter referred to as a "second TRP group") that perform mTRP transmission for the terminal and the first TRP group including the first TRP and the terminal as a hybrid field. The terminal can perform beam sweeping using a reception beam for an optimal transmission beam formed through beam sweeping of the first TRP or an optimal transmission beam set formed through joint beam adjustment of the first TRP group according to an mTRP transmission method of the second TRP group (e.g., non-coherent joint transmission (NCJT) or coherent joint transmission (CJT)). The terminal can compare the performance of the terminal's optimal reception beam before the first TRP participates in the mTRP transmission with the performance of the terminal's optimal reception beam after the first TRP participates in the mTRP through the above-described beam sweeping. Based on the comparison of the terminal's optimal reception beam performance, the terminal can determine whether the first TRP participates in the mTRP transmission. Through the above-described procedure, the terminal can prevent inter-beam interference caused by differences in the types of electromagnetic fields between each TRP and the terminal, and can flexibly operate the mTRP transmission.

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

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

[0033] Figure 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

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

[0035] Figure 4b is a block diagram illustrating a first embodiment of a receiving path.

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

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

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

[0039] Figure 8 is a conceptual diagram illustrating a first embodiment of time-frequency resources in a communication system.

[0040] Figure 9 is a conceptual diagram illustrating an example of the type of electromagnetic field formed between TRPs and terminals.

[0041] FIG. 10 is a conceptual diagram illustrating an embodiment of a terminal performing beam sweeping in an mTRP (multiple transmission and reception points) environment.

[0042] Figure 11 is a conceptual diagram illustrating an embodiment of a procedure for excluding some TRPs (transmission and reception points) from among TRPs participating in mTRP transmission.

[0043] FIG. 12a is a flowchart illustrating an embodiment of a beam management procedure between a first TRP and a terminal.

[0044] FIG. 12b is a flowchart illustrating an embodiment of a beam management procedure between a first TRP and a terminal.

[0045] Figure 13 is a flowchart illustrating an embodiment of a beam management procedure between the first TRP group and a terminal.

[0046] Figure 14a is a flowchart illustrating an embodiment of a terminal that operates mTRP transmission.

[0047] Figure 14b is a flowchart illustrating an embodiment of a terminal that operates mTRP transmission.

[0048] Figure 14c is a flowchart illustrating an embodiment of a terminal that operates mTRP transmission.

[0049] This disclosure may be subject to various modifications and various embodiments. Specific embodiments are illustrated and described in detail in the drawings. However, this is not intended to limit the disclosure to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the disclosure.

[0050] While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present disclosure, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component." The term "and / or" may refer to a combination of multiple related items described herein or to any of multiple related items described herein.

[0051] In the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.” Additionally, in the present disclosure, “at least one of A and B” may mean “at least one of A or B” or “at least one of combinations of one or more of A and B.”

[0052] In the present disclosure, (re)transmission may mean “transmission,” “retransmission,” or “transmission and retransmission,” (re)setting may mean “setting,” “resetting,” or “setting and resetting,” (re)connection may mean “connection,” “reconnection,” or “connection and reconnection,” and (re)connection may mean “connection,” “reconnection,” or “connection and reconnection.”

[0053] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0054] The terminology used in this disclosure is only used to describe specific embodiments and is not intended to limit the present disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this disclosure, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0055] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0056] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. In order to facilitate an overall understanding in describing the present disclosure, the same reference numerals will be used for identical components in the drawings, and redundant descriptions of identical components will be omitted. In addition to the embodiments explicitly described in the present disclosure, operations may be performed according to combinations of embodiments, extensions of embodiments, and / or modifications of embodiments. The performance of some operations may be omitted, and the order of operation may be changed.

[0057] In an embodiment, even if a method (e.g., transmitting or receiving a signal) performed by a first communication node among communication nodes is described, a corresponding second communication node can perform a method (e.g., receiving or transmitting a signal) corresponding to the method performed by the first communication node. That is, if an operation of a UE (user equipment) is described, a corresponding base station can perform an operation corresponding to the operation of the UE. Conversely, if an operation of a base station is described, a corresponding UE can perform an operation corresponding to the operation of the base station.

[0058] A base station may be referred to as a NodeB, an evolved NodeB, a gNodeB (next generation node B), a gNB, a device, an apparatus, a node, a communication node, a BTS (base transceiver station), a RRH (radio remote head), a TRP (transmission reception point), a RU (radio unit), an RSU (road side unit), a radio transceiver, an access point, an access node, etc. A UE may be referred to as a terminal, a device, an apparatus, a node, a communication node, an end node, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, an OBU (on-broad unit), etc.

[0059] In the present disclosure, signaling may be at least one of upper layer signaling, MAC signaling, or PHY (physical) signaling. A message used for upper layer signaling may be referred to as an "upper layer message" or an "upper layer signaling message." A message used for MAC signaling may be referred to as a "MAC message" or a "MAC signaling message." A message used for PHY signaling may be referred to as a "PHY message" or a "PHY signaling message." Upper layer signaling may refer to a transmission and reception operation of system information (e.g., a master information block (MIB), a system information block (SIB)) and / or an RRC message. MAC signaling may refer to a transmission and reception operation of a MAC control element (CE). PHY signaling may refer to a transmission and reception operation of control information (e.g., downlink control information (DCI), uplink control information (UCI), sidelink control information (SCI)).

[0060] In the present disclosure, “an operation (e.g., a transmission operation) is set” may mean that “setting information for the operation (e.g., an information element, a parameter)” and / or “information instructing the performance of the operation” is signaled. “An information element (e.g., a parameter) is set” may mean that the information element is signaled. In the present disclosure, “a signal and / or a channel” may mean a signal, a channel, or “a signal and a channel,” and a signal may be used to mean “a signal and / or a channel.”

[0061] The communication network to which the embodiment is applied is not limited to what is described below, and the embodiment may be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, the communication network may be used in the same sense as the communication system.

[0062] Figure 1 is a conceptual diagram illustrating a first embodiment of a communication system.

[0063] Referring to FIG. 1, the communication system (100) may include a plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6). In addition, the communication system (100) may further include a core network (e.g., a serving-gateway (S-GW), a packet data network (PDN)-gateway (P-GW), a mobility management entity (MME)). If the communication system (100) is a 5G communication system (e.g., a new radio (NR) system), the core network may include an access and mobility management function (AMF), a user plane function (UPF), a session management function (SMF), etc.

[0064] A plurality of communication nodes (110 to 130) can support a communication protocol (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.) specified in the 3GPP (3rd generation partnership project) standard. The plurality of communication nodes (110 to 130) may support CDMA (code division multiple access) technology, WCDMA (wideband CDMA) technology, TDMA (time division multiple access) technology, FDMA (frequency division multiple access) technology, OFDM (orthogonal frequency division multiplexing) technology, Filtered OFDM technology, CP (cyclic prefix)-OFDM technology, DFT-s-OFDM (discrete Fourier transform-spread-OFDM) technology, OFDMA (orthogonal frequency division multiple access) technology, SC (single carrier)-FDMA technology, NOMA (non-orthogonal multiple access) technology, GFDM (generalized frequency division multiplexing) technology, FBMC (filter bank multi-carrier) technology, UFMC (universal filtered multi-carrier) technology, SDMA (space division multiple access) technology, etc. Each of the plurality of communication nodes may have the following structure.

[0065] Figure 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

[0066] Referring to FIG. 2, a communication node (200) may include at least one processor (210), a memory (220), and a transmission / reception device (230) that is connected to a network and performs communication. In addition, the communication node (200) may further include an input interface device (240), an output interface device (250), a storage device (260), etc. Each component included in the communication node (200) may be connected by a bus (270) and communicate with each other.

[0067] The processor (210) can execute program commands stored in at least one of the memory (220) and the storage device (260). The processor (210) may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor in which the methods according to embodiments of the present disclosure are performed. Each of the memory (220) and the storage device (260) may be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (220) may be configured with at least one of a read-only memory (ROM) and a random access memory (RAM).

[0068] Referring again to FIG. 1, the communication system (100) may include a plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) and a plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6). Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) may form a macro cell. Each of the fourth base station (120-1) and the fifth base station (120-2) may form a small cell. The fourth base station (120-1), the third terminal (130-3), and the fourth terminal (130-4) may be within the cell coverage of the first base station (110-1). The second terminal (130-2), the fourth terminal (130-4), and the fifth terminal (130-5) may be within the cell coverage of the second base station (110-2). The fifth base station (120-2), the fourth terminal (130-4), the fifth terminal (130-5), and the sixth terminal (130-6) may be within the cell coverage of the third base station (110-3). The first terminal (130-1) may be within the cell coverage of the fourth base station (120-1). The sixth terminal (130-6) may be within the cell coverage of the fifth base station (120-2).

[0069] Here, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be referred to as a NodeB (NB), an evolved NodeB (eNB), a gNB, an advanced base station (ABS), a high reliability-base station (HR-BS), a base transceiver station (BTS), a radio base station, a radio transceiver, an access point, an access node, a radio access station (RAS), a mobile multihop relay-base station (MMR-BS), a relay station (RS), an advanced relay station (ARS), a high reliability-relay station (HR-RS), a home NodeB (HNB), a home eNodeB (HeNB), a road side unit (RSU), a radio remote head (RRH), a transmission point (TP), a transmission and reception point (TRP), etc.

[0070] Each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as a user equipment (UE), terminal equipment (TE), advanced mobile station (AMS), high reliability-mobile station (HR-MS), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, device, on board unit (OBU), etc.

[0071] Meanwhile, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may operate in a different frequency band or may operate in the same frequency band. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to each other via an ideal backhaul link or a non-ideal backhaul link, and may exchange information with each other via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to the core network via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit a signal received from the core network to the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6), and can transmit a signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) to the core network.

[0072] Additionally, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may support MIMO transmission (e.g., single user (SU)-MIMO, multi user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, sidelink communication (e.g., device to device communication (D2D), proximity services (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) can perform an operation corresponding to the base station (110-1, 110-2, 110-3, 120-1, 120-2) and an operation supported by the base station (110-1, 110-2, 110-3, 120-1, 120-2). For example, the second base station (110-2) can transmit a signal to the fourth terminal (130-4) based on the SU-MIMO scheme, and the fourth terminal (130-4) can receive a signal from the second base station (110-2) by the SU-MIMO scheme. Alternatively, the second base station (110-2) can transmit signals to the fourth terminal (130-4) and the fifth terminal (130-5) based on the MU-MIMO method, and each of the fourth terminal (130-4) and the fifth terminal (130-5) can receive signals from the second base station (110-2) based on the MU-MIMO method.

[0073] Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can transmit a signal to the fourth terminal (130-4) based on the CoMP scheme, and the fourth terminal (130-4) can receive a signal from the first base station (110-1), the second base station (110-2), and the third base station (110-3) based on the CoMP scheme. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit and receive a signal with terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) within its cell coverage based on the CA scheme. Each of the first base station (110-1), the second base station (110-2), and the third base station (110-3) can control sidelink communication between the fourth terminal (130-4) and the fifth terminal (130-5), and each of the fourth terminal (130-4) and the fifth terminal (130-5) can perform sidelink communication under the control of the second base station (110-2) and the third base station (110-3), respectively.

[0074] Meanwhile, communication nodes performing communication in a communication network may be configured as follows. The communication node illustrated in Fig. 3 may be a specific embodiment of the communication node illustrated in Fig. 2.

[0075] Figure 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

[0076] Referring to FIG. 3, each of the first communication node (300a) and the second communication node (300b) may be a base station or a UE. The first communication node (300a) may transmit a signal to the second communication node (300b). The transmission processor (311) included in the first communication node (300a) may receive data (e.g., a data unit) from a data source (310). The transmission processor (311) may receive control information from the controller (316). The control information may include at least one of system information, RRC configuration information (e.g., information configured by RRC signaling), MAC control information (e.g., MAC CE), or PHY control information (e.g., DCI, SCI).

[0077] The transmitting processor (311) may perform a processing operation on data (e.g., an encoding operation, a symbol mapping operation, etc.) to generate data symbol(s). The transmitting processor (311) may perform a processing operation on control information (e.g., an encoding operation, a symbol mapping operation, etc.) to generate control symbol(s). In addition, the transmitting processor (311) may generate synchronization / reference symbol(s) for a synchronization signal and / or a reference signal.

[0078] The Tx MIMO processor (312) may perform a spatial processing operation (e.g., a precoding operation) on data symbol(s), control symbol(s), and / or synchronization / reference symbol(s). The output (e.g., a symbol stream) of the Tx MIMO processor (312) may be provided to modulators (MODs) included in the transceivers (313a to 313t). The modulators (MODs) may perform a processing operation on the symbol stream to generate modulation symbols, and may perform an additional processing operation (e.g., an analog conversion operation, an amplification operation, a filtering operation, an upconversion operation) on the modulation symbols to generate signals. The signals generated by the modulators (MODs) of the transceivers (313a to 313t) may be transmitted via the antennas (314a to 314t).

[0079] Signals transmitted by the first communication node (300a) may be received by antennas (364a to 364r) of the second communication node (300b). Signals received by the antennas (364a to 364r) may be provided to demodulators (DEMODs) included in transceivers (363a to 363r). The demodulator (DEMOD) may perform a processing operation (e.g., a filtering operation, an amplification operation, a downconversion operation, a digital conversion operation) on the signal to obtain samples. The demodulator (DEMOD) may perform an additional processing operation on the samples to obtain symbols. The MIMO detector (362) may perform a MIMO detection operation on the symbols. The receiving processor (361) may perform a processing operation (e.g., a deinterleaving operation, a decoding operation) on the symbols. The output of the receiving processor (361) may be provided to a data sink (360) and a controller (366). For example, data may be provided to the data sink (360), and control information may be provided to the controller (366).

[0080] Meanwhile, the second communication node (300b) can transmit a signal to the first communication node (300a). The transmitting processor (368) included in the second communication node (300b) can receive data (e.g., data units) from a data source (367) and perform a processing operation on the data to generate data symbol(s). The transmitting processor (368) can receive control information from the controller (366) and perform a processing operation on the control information to generate control symbol(s). In addition, the transmitting processor (368) can perform a processing operation on a reference signal to generate reference symbol(s).

[0081] The Tx MIMO processor (369) may perform spatial processing operations (e.g., precoding operations) on data symbol(s), control symbol(s), and / or reference symbol(s). The output (e.g., symbol stream) of the Tx MIMO processor (369) may be provided to modulators (MODs) included in the transceivers (363a to 363t). The modulators (MODs) may perform processing operations on the symbol streams to generate modulation symbols, and may perform additional processing operations (e.g., analog conversion operations, amplification operations, filtering operations, upconversion operations) on the modulation symbols to generate signals. The signals generated by the modulators (MODs) of the transceivers (363a to 363t) may be transmitted via the antennas (364a to 364t).

[0082] Signals transmitted by the second communication node (300b) may be received by the antennas (314a to 314r) of the first communication node (300a). The signals received by the antennas (314a to 314r) may be provided to demodulators (DEMODs) included in the transceivers (313a to 313r). The demodulator (DEMOD) may perform a processing operation (e.g., a filtering operation, an amplification operation, a downconversion operation, a digital conversion operation) on the signal to obtain samples. The demodulator (DEMOD) may perform an additional processing operation on the samples to obtain symbols. The MIMO detector (320) may perform a MIMO detection operation on the symbols. The receiving processor (319) may perform a processing operation (e.g., a deinterleaving operation, a decoding operation) on the symbols. The output of the receiving processor (319) may be provided to a data sink (318) and a controller (316). For example, data may be provided to the data sink (318) and control information may be provided to the controller (316).

[0083] Memories (315 and 365) can store data, control information, and / or program code. Scheduler (317) can perform scheduling operations for communication. The processors (311, 312, 319, 361, 368, 369) and controllers (316, 366) illustrated in FIG. 3 may be the processor (210) illustrated in FIG. 2 and may be used to perform the methods described in the present disclosure.

[0084] FIG. 4a is a block diagram illustrating a first embodiment of a transmission path, and FIG. 4b is a block diagram illustrating a first embodiment of a reception path.

[0085] Referring to FIGS. 4A and 4B, a transmission path (410) may be implemented in a communication node that transmits a signal, and a reception path (420) may be implemented in a communication node that receives a signal. The transmission path (410) may include a channel coding and modulation block (411), an S-to-P (serial-to-parallel) block (512), an N IFFT (Inverse Fast Fourier Transform) block (413), a P-to-S (parallel-to-serial) block (414), a CP (cyclic prefix) addition block (415), and an UC (up-converter) (UC) (416). The receiving path (420) may include a DC (down-converter) (421), a CP removal block (422), an S-to-P block (423), an N FFT block (424), a P-to-S block (425), and a channel decoding and demodulation block (426). Here, N may be a natural number.

[0086] In the transmission path (410), information bits may be input to a channel coding and modulation block (411). The channel coding and modulation block (411) may perform a coding operation (e.g., a low-density parity check (LDPC) coding operation, a polar coding operation, etc.) and a modulation operation (e.g., a quadrature phase shift keying (QPSK), a quadrature amplitude modulation (QAM), etc.) on the information bits. The output of the channel coding and modulation block (411) may be a sequence of modulation symbols.

[0087] The S-to-P block (412) can convert modulation symbols in the frequency domain into parallel symbol streams to generate N parallel symbol streams. N can be an IFFT size or an FFT size. The N IFFT block (413) can perform an IFFT operation on the N parallel symbol streams to generate signals in the time domain. The P-to-S block (414) can convert the output (e.g., parallel signals) of the N IFFT block (413) into a serial signal to generate a serial signal.

[0088] The CP addition block (415) can insert a CP into a signal. The UC (416) can up-convert the frequency of the output of the CP addition block (415) to an RF (radio frequency) frequency. Additionally, the output of the CP addition block (415) can be filtered at the baseband before up-conversion.

[0089] A signal transmitted from a transmission path (410) may be input to a reception path (420). An operation in the reception path (420) may be the reverse operation of the operation in the transmission path (410). A DC (421) may down-convert the frequency of the received signal to a baseband frequency. A CP removal block (422) may remove a CP from a signal. The output of the CP removal block (422) may be a serial signal. An S-to-P block (423) may convert the serial signal into parallel signals. An N FFT block (424) may perform an FFT algorithm to generate N parallel signals. A P-to-S block (425) may convert the parallel signals into a sequence of modulation symbols. A channel decoding and demodulation block (426) may perform a demodulation operation on the modulation symbols and perform a decoding operation on the result of the demodulation operation to restore data.

[0090] In FIGS. 4A and 4B , Discrete Fourier Transform (DFT) and Inverse DFT (IDFT) may be used instead of FFT and IFFT. Each of the blocks (e.g., components) in FIGS. 4A and 4B may be implemented by at least one of hardware, software, or firmware. For example, some of the blocks in FIGS. 4A and 4B may be implemented by software, and the remaining blocks may be implemented by hardware or a “combination of hardware and software.” In FIGS. 4A and 4B , a block may be subdivided into multiple blocks, multiple blocks may be integrated into a single block, some blocks may be omitted, and blocks supporting other functions may be added.

[0091] Figure 5 is a conceptual diagram illustrating a first embodiment of a system frame in a communication system.

[0092] Referring to FIG. 5, time resources in a communication system can be divided into frame units. For example, system frames can be set consecutively in the time domain of the communication system. The length of a system frame can be 10 ms (milliseconds). The system frame number (SFN) can be set from #0 to #1023. In this case, 1024 system frames can be repeated in the time domain of the communication system. For example, the SFN of the system frame after system frame #1023 can be #0.

[0093] A system frame may include two half frames. A half frame may be 5 ms long. A half frame located at the beginning of the system frame may be referred to as "half frame #0," and a half frame located at the end of the system frame may be referred to as "half frame #1." A system frame may include 10 subframes. A subframe may be 1 ms long. The 10 subframes within a system frame may be referred to as "subframes #0-9."

[0094] Figure 6 is a conceptual diagram illustrating a first embodiment of a subframe in a communication system.

[0095] Referring to FIG. 6, one subframe may include n slots, where n may be a natural number. Accordingly, one subframe may be composed of one or more slots.

[0096] Figure 7 is a conceptual diagram illustrating a first embodiment of a slot in a communication system.

[0097] Referring to Figure 7, a single slot may include one or more symbols. A single slot illustrated in Figure 7 may include 14 symbols. The length of a slot may vary depending on the number and length of symbols contained in the slot. Alternatively, the length of a slot may vary depending on the numerology.

[0098] In a communication system, the numerology applied to physical signals and channels may be variable. The numerology may be variable to meet various technical requirements of the communication system. In a communication system applying CP (cyclic prefix)-based OFDM waveform technology, the numerology may include subcarrier spacing and CP length (or CP type). Table 1 may be a first embodiment of a method for configuring a numerology for a CP-OFDM-based communication system. At least some of the numerologies in Table 1 may be supported depending on the frequency band in which the communication system operates. In addition, the communication system may additionally support numerologies not listed in Table 1.

[0099]

[0100] When the subcarrier spacing is 15 kHz (e.g., μ=0), the slot length can be 1 ms. In this case, one system frame can contain 10 slots. When the subcarrier spacing is 30 kHz (e.g., μ=1), the slot length can be 0.5 ms. In this case, one system frame can contain 20 slots.

[0101] When the subcarrier spacing is 60 kHz (e.g., μ=2), the slot length can be 0.25 ms. In this case, one system frame can contain 40 slots. When the subcarrier spacing is 120 kHz (e.g., μ=3), the slot length can be 0.125 ms. In this case, one system frame can contain 80 slots. When the subcarrier spacing is 240 kHz (e.g., μ=4), the slot length can be 0.0625 ms. In this case, one system frame can contain 160 slots.

[0102] A symbol may be configured as a downlink (DL) symbol, a flexible (FL) symbol, or an uplink (UL) symbol. A slot consisting solely of DL symbols may be referred to as a "DL slot," a slot consisting solely of FL symbols may be referred to as an "FL slot," and a slot consisting solely of UL symbols may be referred to as a "UL slot."

[0103] The slot format can be semi-statically configured by higher layer signaling (e.g., RRC signaling). Information indicating the semi-static slot format can be included in the system information, and the semi-static slot format can be configured cell-specifically. In addition, the semi-static slot format can be additionally configured for each terminal through terminal-specific higher layer signaling (e.g., RRC signaling). The flexible symbol of the cell-specifically configured slot format can be overridden to a downlink symbol or an uplink symbol by terminal-specific higher layer signaling. In addition, the slot format can be dynamically indicated by physical layer signaling (e.g., a slot format indicator (SFI) included in DCI). The semi-statically configured slot format can be overridden by a dynamically indicated slot format. For example, the semi-statically configured flexible symbol can be overridden to a downlink symbol or an uplink symbol by the SFI.

[0104] The reference signal may be a channel state information-reference signal (CSI-RS), a sounding reference signal (SRS), a demodulation-reference signal (DM-RS), a phase tracking-reference signal (PT-RS), etc. The channel may be a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), etc. In the present disclosure, a control channel may mean a PDCCH, a PUCCH, or a PSCCH, and a data channel may mean a PDSCH, a PUSCH, or a PSSCH.

[0105] Figure 8 is a conceptual diagram illustrating a first embodiment of time-frequency resources in a communication system.

[0106] Referring to FIG. 8, a resource consisting of one symbol (e.g., an OFDM symbol) in the time domain and one subcarrier in the frequency domain may be defined as a "RE (resource element)". Resources consisting of one OFDM symbol in the time domain and K subcarriers in the frequency domain may be defined as a "REG (resource element group)". A REG may include K REs. A REG may be used as a basic unit for resource allocation in the frequency domain. K may be a natural number. For example, K may be 12. N may be a natural number. In the slot illustrated in FIG. 7, N may be 14. N OFDM symbols may be used as a basic unit for resource allocation in the time domain.

[0107] In the present disclosure, RB may mean CRB (common RB). Alternatively, RB may mean PRB or VRB (virtual RB). In a communication system, CRB may mean RB that constitutes a set of consecutive RBs (e.g., a common RB grid) based on a reference frequency (e.g., point A). Carriers and / or bandwidth portions may be arranged on the common RB grid. That is, the carrier and / or bandwidth portions may be composed of CRB(s). RBs or CRBs that constitute the bandwidth portions may be referred to as PRBs, and within the bandwidth portions, the CRB index may be appropriately converted to the PRB index.

[0108] Downlink data can be transmitted via the PDSCH. The base station can transmit PDSCH configuration information (e.g., scheduling information) to the terminal via the PDCCH. The terminal can obtain the PDSCH configuration information by receiving the PDCCH (e.g., downlink control information (DCI)). For example, the PDSCH configuration information can include the MCS (modulation coding scheme) used for transmitting and receiving the PDSCH, time resource information of the PDSCH, frequency resource information of the PDSCH, feedback resource information for the PDSCH, etc. The PDSCH can refer to a radio resource through which downlink data is transmitted and received. Alternatively, the PDSCH can refer to the downlink data itself. The PDCCH can refer to a radio resource through which downlink control information (e.g., DCI) is transmitted and received. Alternatively, the PDCCH can refer to the downlink control information itself.

[0109] A terminal can perform a monitoring operation on the PDCCH to receive a PDSCH transmitted from a base station. The base station can inform the terminal of the configuration information for the PDCCH monitoring operation using a higher layer message (e.g., an RRC (radio resource control) message). The configuration information for the PDCCH monitoring operation can include CORESET (control resource set) information and search space information.

[0110] CORESET information may include PDCCH DMRS (demodulation reference signal) information, PDCCH precoding information, PDCCH occasion information, etc. The PDCCH DMRS may be a DMRS used to demodulate the PDCCH. The PDCCH occasion may be a region where the PDCCH can exist. That is, the PDCCH occasion may be a region where DCI can be transmitted. The PDCCH occasion may be referred to as a PDCCH candidate. The PDCCH occasion information may include time resource information and frequency resource information of the PDCCH occasion. In the time domain, the length of the PDCCH occasion may be indicated in symbol units. In the frequency domain, the size of the PDCCH occasion may be indicated in RB units (e.g., in PRB (physical resource block) units or CRB (common resource block) units).

[0111] The search space information may include a coreset identifier (ID) associated with the search space, a period of PDCCH monitoring, and / or an offset. The period and offset of PDCCH monitoring may each be indicated on a slot-by-slot basis. In addition, the search space information may further include an index of the symbol at which the PDCCH monitoring operation begins.

[0112] A base station can configure a bandwidth part (BWP) for downlink communication. The BWP can be configured differently for each terminal. The base station can inform the terminal of the BWP configuration information using higher layer signaling. The higher layer signaling can mean "transmission operation of system information" and / or "transmission operation of RRC (radio resource control) message." The number of BWPs configured for one terminal can be one or more. The terminal can receive BWP configuration information from the base station and check the BWP(s) configured by the base station based on the BWP configuration information. When multiple BWPs are configured for downlink communication, the base station can activate one or more BWPs among the multiple BWPs. The base station can transmit the configuration information of the activated BWP(s) to the terminal using at least one of higher layer signaling, a medium access control (MAC) control element (CE), or DCI. The base station can perform downlink communication using the activated BWP(s). The terminal can identify the activated BWP(s) by receiving configuration information of the activated BWP(s) from the base station, and perform a downlink reception operation in the activated BWP(s).

[0113] The type of electromagnetic field can be classified into near-field or far-field. The criterion for distinguishing the type of electromagnetic field may be the distance (hereinafter referred to as the “reference distance”) from the transmission source of the signals (e.g., antennas of a base station). The reference distance may be as shown in Mathematical Expression 1 below. In Mathematical Expression 1, R, D, Φ, and λ may represent the reference distance, the maximum length of the antenna array, the maximum allowable phase error, and the wavelength of the signal, respectively. The maximum allowable phase error may represent the maximum phase difference between signals received by or transmitted from antennas belonging to the antenna array.

[0114]

[0115] If the maximum allowable phase error is greater than π / 8, the plane wave assumption may not be established, and if the plane wave assumption is not established, the Fraunhofer approximation may not be applied. The Fraunhofer approximation can be a method of predicting the diffraction pattern of a signal when the signal is assumed to be a plane wave. If the Fraunhofer approximation is not applied, signals received by receivers (e.g., terminals) may not be determined as a linear function for each index of the antennas belonging to the terminal. The Rayleigh distance in Equation 1 may mean a reference distance when the wavelength in Equation 2 is π / 8. When signals transmitted from a base station further than the Rayleigh distance are received by a terminal, the phase difference between the signals received by the terminal may not exceed π / 8. If the phase difference between the signals received by the terminal does not exceed π / 8, the plane wave assumption can be established.

[0116] If the plane wave assumption holds, the terminal can determine the phase values ​​of the received signals as a linear function for each index of the antennas belonging to the terminal. If the plane wave assumption does not hold (for example, if the terminal is in the near field), the terminal cannot determine the phase values ​​of the received signals as a linear function for each index of the antennas belonging to the terminal. If the plane wave assumption does not hold, the phase values ​​of the signals received at the terminal can be determined as a nonlinear function for each index of the antennas belonging to the terminal. If the phase values ​​are determined as a nonlinear function, the factors considered in determining the phase values ​​may be not only the index of each antenna belonging to the terminal, but also the incidence angle of the signals received at the terminal or the distance between the base station and the terminal. Therefore, the design of the beamforming vector for the terminal in the far field may be different from the design of the beamforming vector for the terminal in the near field. Therefore, a beam formed based on the design of a beamforming vector for a terminal belonging to a far field may be referred to as a 'far field beam', and a beam formed based on the design of a beamforming vector for a terminal belonging to a near field may be referred to as a 'near field beam'.

[0117] A hybrid field can be considered as a type of electromagnetic field. In 6G communication networks, due to the increase in operating frequency bandwidth and the increase in the size of antenna arrays, the area considered a far-field in NR communication networks can be considered a near-field. The type of electromagnetic field can be determined between a TRP and a terminal. If the type of electromagnetic field between the terminal and the first TRP is a near-field, and the type of electromagnetic field between the terminal and the second TRP is a far-field, the terminal can form a hybrid field with TRPs including the first TRP and the second TRP. A terminal belonging to the hybrid field can receive both far-field beams and near-field beams from different TRPs.

[0118] In NR communications networks, mTRP (multiple transmission and reception points) operation refers to a technology in which multiple transmission and reception points (TRPs) physically separated from a base station cooperate to communicate with a single terminal. mTRP can prevent QoS (quality of service) degradation and inter-cell interference experienced by terminals located at cell edges. mTRP can also provide additional paths in environments with limited line of sight (LoS).

[0119] Non-coherent joint transmission (NCJT) and coherent joint transmission (CJT) modes can be considered as types of mTRP operation. When performing mTRP operation, which mTRP operation mode is performed can be determined by the environment of the cell to which the TRPs belong, the connectivity of the backhaul link, etc. In the CJT mode, the base station (or network) can coordinate multiple TRPs so that multiple TRPs can cooperate with each other to support a single terminal. In the NCJT mode, each TRP can independently support a terminal. In the NCJT mode, each TRP can independently perform scheduling, precoding matrix selection, modulation scheme selection, or coding scheme selection. Therefore, interference between TRPs may occur.

[0120] In a 6G communication network, base stations and terminals can use higher frequency bands than the FR (frequency range) 2 band of the NR network. In a 6G communication network, the size or length of antenna arrays belonging to base stations and terminals can be increased or lengthened. Therefore, in a 6G communication network, the area considered as the far field in NR communication networks can be considered the near field. The type of electromagnetic field between TRPs performing mTRP transmission and a terminal in an NR communication network can be considered the far field. TRPs performing mTRP transmission in an NR communication network can form far-field beams for the terminal. When a new TRP participates in mTRP transmission in an NR communication network, improved reception performance of the terminal can be guaranteed. However, in a 6G communication network, the types of electromagnetic fields formed between TRPs performing mTRP transmission and a terminal may differ.

[0121] In a 6G communication network, some TRPs performing mTRP transmission may transmit far-field beams to the terminal, while others may transmit near-field beams to the terminal. Interference may occur between the far-field beams and the near-field beams. When multiple TRPs perform mTRP transmission for a single terminal, other TRPs may participate in the mTRP transmission. However, if the type of electromagnetic field associated with the beam formed by the TRP participating in the mTRP transmission differs from the type of electromagnetic field associated with the beam formed by the TRP performing the existing mTRP transmission, the performance of the mTRP operation may be reduced. In a 6G communication network, when a new TRP participates in mTRP transmission, an improvement in the terminal's reception beam performance cannot be guaranteed. Therefore, to operate mTRP operation flexibly, it may be necessary to define procedures for determining whether a new TRP participates in mTRP transmission, procedures for excluding a new TRP from mTRP operation, and procedures for inducing a new TRP to participate in mTRP transmission. Among the above-described procedures, the procedure for determining whether a new TRP participates in mTRP transmission may involve comparing the performance of the terminal's receive beams before and after the new TRP participates in mTRP transmission. Therefore, the procedure for determining whether a new TRP participates in mTRP transmission may include a beam management procedure.

[0122] Hereinafter, the procedures proposed by the present disclosure will be briefly described. Depending on the type of electromagnetic field between one or more TRP(s) performing mTRP transmission for a terminal (hereinafter referred to as "one or more second TRP(s)" or "second TRP group") and the terminal and the type of electromagnetic field between a candidate TRP (e.g., a first TRP) participating in the mTRP transmission and the terminal, the type of electromagnetic field between the TRPs including the second TRP group and the first TRP (hereinafter referred to as "the first TRP group") and the terminal can be determined. The first TRP group can perform mTRP transmission for the terminal through cooperation between the second TRP group and the first TRP. Depending on the type of mTRP operation, the terminal can perform a beam management procedure with the first TRP or the first TRP group.

[0123] The terminal can compare the performance (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), or channel quality indicator (CQI)) between the optimal reception beams of the terminal before and after the first TRP participates. The terminal can determine that the first TRP does not participate in the mTRP transmission by comparing the RSRP values. That is, the first TRP can be excluded from the first TRP group. The second TRP group can set the transmission beam set that was set before the first TRP participated in the mTRP transmission as a new transmission beam set. The terminal can set the reception beam that was set before the first TRP participated in the mTRP transmission as a new reception beam. The terminal can periodically measure the RSRP values ​​of the received beams, and based on the measurement results, can request the candidate TRPs participating in the mTRP transmission to participate in the mTRP transmission. The candidate TRPs participating in the mTRP transmission can be the same TRP as the first TRP, or different TRPs.

[0124] Figure 9 is a conceptual diagram illustrating an example of the type of electromagnetic field formed between TRPs and terminals.

[0125] Referring to FIG. 9, a communication system may include TRPs (910, 920) and a terminal (930). TRP (910) may be one TRP (hereinafter referred to as 'TRP A') of a second TRP group. TRP A may be a coordinating TRP of the second TRP group. The coordinating TRP may be a TRP that performs beam management for beams formed by TRPs, beam adjustment (e.g., phase and / or timing adjustment of beams) so that beams formed by TRPs are aligned, resource allocation for TRPs, or reception of measurement reports from terminals, among the TRPs that perform mTRP transmission. Coordination between TRPs participating in mTRP transmission may be performed by a base station (or network) or by a coordinating TRP, which is one of the TRPs participating in mTRP transmission.

[0126] The type of electromagnetic field between the second TRP group or TRP A and the terminal may be a far-field. The type of electromagnetic field between the first TRP and the terminal may be a near-field. The terminal may simultaneously belong to the far-field formed by the second TRP group and the near-field formed by the first TRP. The type of electromagnetic field between the terminal and the first TRP group, including the second TRP group and the first TRP, may be a mixed field.

[0127] The second TRP group can transmit far-field beams to the terminal. The far-field beams can be steered to a specific angle. However, the far-field beams may not be steered to a specific location. The first TRP can transmit near-field beams to the terminal. The near-field beams can be steered to a specific location as well as a specific angle.

[0128]

[0129] The terminal can obtain information in advance about the type of electromagnetic field between the terminal and the second TRP group that has already performed mTRP transmission for the terminal. The terminal can determine the type of electromagnetic field between the first TRP and the terminal based on the information received from the first TRP. If the type of electromagnetic field between the second TRP group and the terminal is different from the type of electromagnetic field between the first TRP and the terminal, the terminal can determine the type of electromagnetic field between the first TRP group and the terminal as a hybrid field.

[0130] Referring to Table 2, the type of electromagnetic field between the first TRP and the terminal may be determined based on PT (phase tracking)-RS (reference signals) received at the terminal from the first TRP. The first TRP may transmit to the terminal first information including at least one of information on a pattern of PT-RSs, information on a time interval in which the PT-RSs are transmitted, or TRP identifier (e.g., TRP ID) information. The pattern of PT-RSs may refer to a structure in which PT-RSs are repeatedly arranged on a resource grid. The pattern of PT-RSs may include at least one of information on a slot in which the PT-RS is transmitted, information on a symbol index in which the PT-RS is located, information on a period in which the PT-RS is transmitted, or information on a density of PT-RSs in a frequency domain.

[0131] The first TRP may transmit PT-RSs to the terminal after transmitting the first information. If the first TRP and the terminal are in an RRC (radio resource control) connection state, the first TRP may transmit the first information to the terminal via a system information block (SIB), downlink control information (DCI), an RRC reconfiguration message, or other RRC signaling. If the first TRP does not form a serving cell for the terminal, the first TRP may transmit the first information to the terminal via signaling radio bearer (SRB) 3.

[0132] A terminal may receive first information from a first TRP. The terminal may explicitly identify the first TRP from a TRP identifier. Alternatively, the terminal may implicitly identify the first TRP from a correspondence between a control resource set (CORESET) ID and a transmission configuration indication (TCI) state. After receiving the first information, the terminal may receive PT-RSs from the first TRP based on the first information. The terminal may determine the phase of the PT-RSs received by each antenna element belonging to the terminal. The terminal may derive a phase difference between the PT-RSs received by the antenna elements. The terminal may compare the maximum phase difference among the derived phase differences with a threshold for determining the type of an electromagnetic field. If the maximum phase difference is determined to be greater than the threshold, the terminal may determine that the type of the electromagnetic field between the first TRP and the terminal is a near-field.

[0133] The first TRP can define a reference signal corresponding to a near field and a reference signal corresponding to a far field. The reference signal corresponding to the near field and the reference signal corresponding to the far field can be distinguished based on a sequence of the reference signals (e.g., a pseudo-random sequence or a Gold sequence). The first TRP can periodically transmit the reference signal corresponding to the near field and the reference signal corresponding to the far field to the terminal. The terminal can receive the reference signal corresponding to the near field and the reference signal corresponding to the far field, and compare the performance of each reference signal (e.g., reference signal received power (RSRP)). If the performance of the reference signal corresponding to the near field is determined to be better, the terminal can determine the type of the electromagnetic field between the first TRP and the terminal as the near field.

[0134] The terminal can determine the type of electromagnetic field between the first TRP and the terminal based on the Rayleigh distance as well as the maximum phase difference. The first information received by the terminal may further include at least one of information on a frequency band used for communication between the first TRP and the terminal, information on the size of an antenna array belonging to the first TRP, information on the maximum length of an antenna array belonging to the first TRP, or information on the distance between the first TRP and the terminal. The terminal can derive the Rayleigh distance based on the received first information. The terminal can determine that the distance between the first TRP and the terminal is shorter than the Rayleigh distance. The terminal can determine that the type of electromagnetic field between the first TRP and the terminal is a near-field.

[0135]

[0136] Referring to Table 3, the terminal can know in advance that the type of electromagnetic field between the second TRP group and the terminal is a far-field field. The terminal can confirm that the type of electromagnetic field between the first TRP and the terminal is a near-field field through the operations disclosed in the description of Table 2. Therefore, the terminal can determine that the type of electromagnetic field between the first TRP group, which includes the second TRP group and the first TRP, and the terminal is a mixed field.

[0137] If it is determined that the type of electromagnetic field between the first TRP group and the terminal is not a mixed field, the operations derived from Tables 4 to 7 may be performed, and the operations derived from Tables 8 to 11 may not be performed.

[0138] FIG. 10 is a conceptual diagram illustrating an embodiment of a terminal performing beam sweeping in an mTRP (multiple transmission and reception points) environment.

[0139] Referring to FIG. 10, a terminal (1030) performing beam sweeping after the first TRP (1020) participates in mTRP transmission can be identified. Beam sweeping by the terminal (1030) can be performed on transmission beams formed by the first TRP (1020) in the NCJT method. Alternatively, beam sweeping by the terminal (1030) can be performed on transmission beams formed by the first TRP group (1010, 1020) in the CJT method.

[0140] The terminal (1030) can determine the optimal reception beam among the reception beams formed by the terminal through beam sweeping. The terminal (1030) can compare the performance (e.g., RSRP) between the reception beams before and after the first TRP participates in mTRP transmission. The terminal (1030) can determine whether the first TRP (1020) will participate in mTRP transmission by comparing the performance between the reception beams.

[0141]

[0142] Referring to Table 4, the terminal may transmit information on the type of electromagnetic field between the first TRP and the terminal derived through the operations disclosed in the description of Table 2 to the first TRP. The type of electromagnetic field between the first TRP and the terminal may be a near-field.

[0143] When the terminal and the first TRP are in an RRC connection state, the terminal may transmit information on the type of electromagnetic field between the first TRP and the terminal to the first TRP through uplink control information (UCI), a UEAssistanceInformation message, or other RRC signaling. When the terminal is not in an RRC connection state with the first TRP (e.g., in an RRC idle state or an RRC inactive state), the terminal may transmit information on the type of electromagnetic field between the first TRP and the terminal to the first TRP through an SN UEAssistanceInformation message used in Msg 1, Msg A, SRB 3, or other RRC signaling.

[0144]

[0145] When the mTRP transmission method performed for a terminal is NCJT, each TRP can independently support the terminal. Therefore, the first TRP can perform the terminal and beam management procedure independently from the second TRP group. The first TRP can determine the optimal transmission beam through the beam management procedure described above. Before the first TRP performs the terminal and beam management procedure, each TRP belonging to the second TRP group can perform the terminal and beam management procedure to determine the optimal transmission beams. Regardless of whether the first TRP participates in the mTRP transmission, each TRP belonging to the second TRP group can communicate with the terminal through the determined optimal transmission beams.

[0146] Referring to Table 5, the first TRP may perform beam sweeping using transmission beams after receiving information on the type of electromagnetic field between the first TRP and the terminal from the terminal. The first TRP may perform a beam management procedure consistent with the near field. Channel state information (CSI)-reference signals (RSs) and beam index information of each of the transmission beams may be transmitted to the terminal through the transmission beams. The beam index information may be transmitted to the terminal through DCI, media access control (MAC)-control element (CE), an RRC reconfiguration message, or other RRC signaling. The transmission beams may be near-field beams consistent with the information on the type of electromagnetic field received from the terminal. If the type of electromagnetic field between the first TRP and the terminal is the far field, the first TRP may use a beam management procedure used in an NR communication network.

[0147] A terminal that receives transmission beams formed through beam sweeping of a first TRP can measure RSRP values ​​of each of the transmission beams. The terminal can determine transmission beams (e.g., candidate beams) having an RSRP value exceeding a pre-determined RSRP value among the transmission beams. The terminal can transmit identification information (e.g., beam index) for each of the candidate beams and information on the RSRP values ​​of each of the candidate beams to the first TRP. Alternatively, the terminal may not determine the candidate beams, but report beam index information of all transmission beams and RSRP values ​​of all transmission beams to the first TRP. The first TRP can determine an optimal transmission beam among the candidate beams or the transmission beams based on the RSRP values ​​of the candidate beams or the RSRP values ​​of all transmission beams. Since the "first TRP near-field beam #4" among the transmission beams of the first TRP has the largest RSRP value, the "first TRP near-field beam #4" can be determined as the optimal transmission beam.

[0148] The procedure for a terminal to report RSRP values ​​of candidate beams or transmission beams to a first TRP may be as follows. The first TRP may transmit a UEInformationRequest message to the terminal using RRC signaling. The UEInformationRequest message may be a message instructing the terminal to report performance of beams. After receiving the UEInformationRequest message, the terminal may transmit the RSRP values ​​of the candidate beams or the RSRP values ​​of all transmission beams to the first TRP. Alternatively, the first TRP may transmit an SIB including a message instructing the terminal to report performance of beams. After receiving the SIB, the terminal may transmit the RSRP values ​​of the candidate beams or the RSRP values ​​of all transmission beams to the first TRP through a MeasurementReport message or a UEAssistanceInformation message.

[0149]

[0150] When the mTRP transmission method performed for a terminal is CJT, the base station (or network) can coordinate the first TRP group so that the first TRP group can cooperate to support the terminal. Alternatively, the coordinating TRP, which is one of the first TRP groups, can coordinate the other TRPs so that the first TRP group can cooperate to support the terminal.

[0151] Referring to Table 6, the first TRP group can set an optimal transmission beam set including optimal transmission beams for performing mTRP transmission for a terminal through joint beam adjustment. The first TRP group can determine whether to perform information cooperative beam adjustment based on at least one of a delay request set for the terminal or a frequency band allocated to each of the TRPs belonging to the first TRP group. The first TRP group (or joint TRP) can know the delay request set for the terminal in advance. Alternatively, the joint TRP can transmit an instruction to the terminal requesting the terminal to report the delay request set for the terminal through a UEInformationRequest message. The terminal can transmit information about the delay request set for itself to the joint TRP through a UEInformationResponse message in response to the UEInformationRequest message.

[0152] The first TRP group can transmit and receive at least one of information on a CSI-RS transmission timing, information on a CSI-RS transmission pattern (e.g., a structure in which CSI-RSs are arranged on a resource grid), information on the number of candidate beams that can be set for each TRP, or information on a beam switching cycle to and from each other through a backhaul link, a base station (or network) controlling the first TRP group, or at least one of the terminals. When the information is transmitted and received through the terminal, the information can be transmitted and received through DCI or other RRC signaling. The first TRP group or the coordinated TRP can set an optimal transmission beam set (e.g., {TRB B far-field beam #2, 1st TRP near-field beam #3}) including optimal transmission beams for performing mTRP transmission to the terminal based on the transmitted and received information.

[0153]

[0154] Regardless of the mTRP transmission method (e.g., NCJT or CJT) performed on the terminal, the terminal can perform beam sweeping using the terminal's reception beams. The terminal can determine an optimal reception beam through the above-described beam sweeping. Regardless of the mTRP operation method, the terminal can set a beam pair set including the optimal transmission beams of the first TRP group and its own optimal reception beam. An element of the beam pair set can be a beam pair composed of the optimal transmission beam of each of the TRPs belonging to the first TRP group and the optimal reception beam of the terminal. Communication through beamforming can be performed between the first TRP group and the terminal based on the above-described beam pair set.

[0155] The above-described beam sweeping can be performed for the optimal transmission beam of the first TRP disclosed in the description for Table 5. That is, the terminal can sequentially form reception beams in the time domain for the optimal transmission beam of the first TRP. Alternatively, the beam sweeping can be performed for the optimal transmission beam set of the first TRP group disclosed in the description for Table 6. That is, the terminal can sequentially form reception beams in the time domain for the transmission beams included in the optimal transmission beam set of the first TRP group. The terminal can determine the optimal reception beam of the terminal through beam sweeping.

[0156] In the NCJT scheme, the terminal can set a first beam pair set including optimal transmission beams of the first TRP and second TRP groups and optimal reception beams of the terminal. An element of the first beam pair set may be a beam pair composed of an optimal transmission beam of each of the TRPs belonging to the first TRP and second TRP groups and an optimal reception beam of the terminal. In the NCJT scheme, the first TRP groups do not cooperate with each other to perform mTRP transmission to the terminal, but each of the TRPs belonging to the first TRP and second TRP groups can independently perform mTRP transmission to the terminal. Therefore, in the NCJT scheme, the first beam pair set may be regarded as including, as an element, a beam pair composed of each of the optimal transmission beams of the first TRP group including the first TRP and second TRP groups and an optimal reception beam of the terminal. Alternatively, the terminal can set a first beam pair set including, as an element, a beam pair composed of an optimal transmission beam of each of the TRPs belonging to the first TRP group and an optimal reception beam of the terminal in the CJT scheme. Before the terminal performs the operations disclosed in the description of Table 2, the terminal may set a second beam pair set including as elements a beam pair composed of an optimal transmission beam of each of the TRPs belonging to the second TRP group and an optimal reception beam of the terminal.

[0157] Referring to Table 7, the RSRP values ​​of each of the reception beams formed by beam sweeping of the terminal can be confirmed. Among the reception beams disclosed in Table 7, "Terminal Beam #3" has the largest RSPR value, so "Terminal Beam #3" can be determined as the optimal reception beam.

[0158]

[0159] The optimal reception beam disclosed in Table 7 may be a reception beam set under a situation after the first TRP participates in mTRP transmission (e.g., a situation in which the first TRP group performs mTRP transmission to the terminal). The terminal may obtain the RSRP value of the optimal reception beam in advance under a situation before the first TRP participates in mTRP transmission (e.g., a situation in which only the second TRP group performs mTRP transmission to the terminal). The terminal may compare the performance of the reception beams set before and after the first TRP participates in mTRP transmission. The terminal may determine whether the first TRP participates in mTRP transmission through a performance comparison between the reception beams.

[0160] Referring to Table 8, the RSRP value of the terminal's receive beam set before the first TRP participates in the mTRP transmission may be 88 dBm. The RSRP value of the terminal's receive beam set after the first TRP participates in the mTRP transmission may be 83 dBm. It can be confirmed that the performance of the terminal's receive beam deteriorates after the first TRP participates in the mTRP transmission. Therefore, the terminal may determine that the first TRP does not participate in the mTRP transmission.

[0161] Figure 11 is a conceptual diagram illustrating an embodiment of a procedure for excluding some TRPs (transmission and reception points) from among TRPs participating in mTRP transmission.

[0162] Referring to FIG. 11, the terminal (1130) may determine that the first TRP (1120) does not participate in mTRP transmission. The terminal (1130) may transmit a signal transmission suspension request to the first TRP (1120). The first TRP (1120) that receives the signal transmission suspension request may be excluded from the first TRP group (1110, 1120).

[0163]

[0164] Referring to Table 9, the terminal may determine that the first TRP does not participate in the mTRP transmission based on a performance comparison between the terminal's reception beams before and after the first TRP participates in the mTRP. The terminal may exclude the first TRP from the first TRP group. The terminal may transmit a signal transmission stop request (TRPstopRequest) to the first TRP. The first TRP that receives the signal transmission stop request may be excluded from the first TRP group.

[0165] In the CJT method, if the optimal transmission beam set of the second TRP group changes after the first TRP participates in the mTRP (e.g., if the operations derived from Table 6 are performed), the terminal may transmit a transmission beam set recovery request (TRPrestoreRequest) to the second TRP group or to an adjustment TRP (e.g., TRP A) that is one of the TRPs belonging to the second TRP group. TRPstopRequest and TRPrestoreRequest may be newly defined RRC signaling.

[0166] A second TRP group or TRP A that receives a request to restore a set of transmission beams may change the first set of transmission beams set after the first TRP participates in the mTRP transmission to the second set of transmission beams set before the first TRP participates in the mTRP (e.g., before the operations deriving Table 2 are performed). The first set of transmission beams may be a subset of the first set of beams disclosed in the description of Table 7.

[0167] During the process of performing the operations derived from Table 9, the terminal may be in an RRC connection state with each of the TRPs belonging to the first TRP group. Accordingly, the terminal may transmit a TRPstopRequest and / or a TRPrestoreRequest via UCI or UEAssistanceInformation.

[0168]

[0169] Referring to Table 10, the terminal may determine that the first TRP does not participate in the mTRP transmission based on a performance comparison between the terminal's receive beams before and after the first TRP participates in the mTRP. The terminal may change the terminal's optimal receive beam set under a situation after the first TRP participates in the mTRP transmission (e.g., the optimal receive beam set when the first TRP group performs mTRP transmission for the terminal) to the terminal's optimal receive beam set under a situation before the first TRP participates in the mTRP transmission (e.g., the terminal's optimal receive beam set when only the second TRP group performs mTRP transmission for the terminal).

[0170] The terminal can change the "terminal beam #3" set by the operations derived from Table 7 to the "terminal beam #1", which is the terminal's optimal receiving beam set before the operations derived from Table 2 are performed.

[0171]

[0172] In a situation where the first TRP does not perform mTRP transmission, the terminal can cause an mTRP transmission participation candidate TRP (e.g., the first TRP) to participate in the mTRP transmission if a predefined condition is satisfied. The terminal can periodically measure the RSRP value of the combined beam according to a set cycle (e.g., t_{mTRP})) based on an mTRP timer set in the terminal. The combined beam can mean a beam in which beams received from a second TRP group performing mTRP transmission for the terminal are coherently combined at the terminal. The terminal can determine whether the measured RSRP value exceeds a predefined threshold (e.g., δ_{threshold})). If the terminal determines that the measured RSRP value exceeds the predefined threshold, the terminal can transmit an mTRP transmission participation request message to the mTRP transmission participation candidate TRP. The mTRP transmission participation candidate TRP that receives the message can participate in the mTRP transmission for the terminal.

[0173] Whether to transmit a request message for mTRP transmission participation of a terminal may be determined based on the distance moved by the terminal as well as the RSRP value. The second TRP group or the adjusted TRP (e.g., TRP A) may measure the location of the terminal or the distance moved by the terminal according to a predetermined cycle. The second TRP group or the adjusted TRP may determine whether the distance moved by the terminal during the predetermined cycle exceeds a movement distance threshold of the terminal. If it is determined that the distance moved by the terminal exceeds the movement distance threshold of the terminal, the second TRP group or the adjusted TRP may transmit an instruction requesting the terminal to report the RSRP value of the beam received by the terminal. The terminal may report the RSRP value of the combined beam to the second TRP group or the adjusted TRP according to the instruction described above. The second TRP group or the adjusted TRP may determine whether the reported RSRP value exceeds δ_{threshold}. If the RSRP value is determined to exceed δ_{threshold}, the second TRP group or the coordinating TRP may send an mTRP transmission participation request message to the mTRP transmission participation candidate TRP. The mTRP transmission participation candidate TRP that receives the message may participate in the mTRP transmission for the terminal.

[0174] FIG. 12a is a flowchart illustrating an embodiment of a beam management procedure between a first TRP and a terminal.

[0175] The operations derived from Tables 2 to 5 can be applied to the embodiments disclosed in FIGS. 12a and 12b. The operations disclosed in the description of FIG. 12b can be performed after the operations disclosed in the description of FIG. 12a are performed.

[0176] Referring to FIG. 12A, a terminal may receive first information for determining the type of electromagnetic field between a first TRP and the terminal from a first TRP (S1200). After receiving PT-RSs from the first TRP, the terminal may determine the type of electromagnetic field between the terminal and the first TPR based on the first information (S1210). The terminal may determine information on the type of electromagnetic field between the first TRP group and the terminal based on the information on the type of electromagnetic field between the first TRP and the terminal (S1220). The terminal may transmit information on the type of electromagnetic field between the first TRP and the terminal to the first TRP (S1230).

[0177] FIG. 12b is a flowchart illustrating an embodiment of a beam management procedure between a first TRP and a terminal.

[0178] Referring to FIG. 12B, the first TRP may perform beam sweeping using transmission beams that match the type of electromagnetic field between the terminal and the first TRP (S1240). The terminal may measure RSRP values ​​of transmission beams received through beam sweeping, and determine candidate beams among the transmission beams based on the measured RSRP values ​​(S1250). The terminal may transmit a report on the candidate beams to the first TRP (S1260). The first TRP may determine an optimal transmission beam based on the RSRP values ​​included in the report (S1270).

[0179] Figure 13 is a flowchart illustrating an embodiment of a beam management procedure between the first TRP group and a terminal.

[0180] The operations derived from Table 6 can be applied to the embodiment illustrated in Fig. 13.

[0181] Referring to FIG. 13, the first TRP group or the coordinating TRP may transmit a report request regarding the delay request set for the terminal to the terminal (S1300). The terminal receiving the report request may transmit a report regarding the delay request set for the terminal to the first TRP group or the coordinating TRP (S1310).

[0182] The first TRP group or the coordination TRP, which has received a report on the delay request set for the terminal, can determine whether to perform cooperative beam adjustment based on the delay request set for the terminal (S1320). If it is determined that cooperative beam adjustment is to be performed, the first TRP group or the coordination TRP can transmit and receive information for cooperative beam adjustment between the first TRP groups (S1330). The first TRP group or the coordination TRP can set an optimal transmission beam set including optimal transmission beams for performing mTRP transmission for the terminal (S1340).

[0183] Figure 14a is a flowchart illustrating an embodiment of a terminal that operates mTRP transmission.

[0184] The operations derived from Tables 7 to 11 can be applied to the embodiments illustrated in FIGS. 14A to 14C. The operations disclosed in the description of FIG. 14B can be performed after the operations disclosed in the description of FIG. 14A are performed. The operations disclosed in the description of FIG. 14C can be performed after the operations disclosed in the description of FIG. 14B are performed.

[0185] Referring to FIG. 14A, a terminal may perform beam sweeping using reception beams for transmission beams formed by a first TRP group or a first TRP. The terminal may determine an optimal reception beam of the terminal through beam sweeping (S1400) and measure the performance of the optimal reception beam. The terminal may compare the performance of the optimal reception beam of the terminal set under a situation before the first TRP participates in mTRP transmission with the performance of the optimal reception beam of the terminal set under a situation after the first TRP participates in mTRP transmission (S1410). The terminal may determine whether the first TRP participates in mTRP transmission by comparing the performance between the optimal reception beams of the terminal before and after the first TRP participates in mTRP transmission (S1420).

[0186] Figure 14b is a flowchart illustrating an embodiment of a terminal that operates mTRP transmission.

[0187] Referring to FIG. 14B, if it is determined that the first TRP does not participate in mTRP transmission, the terminal may transmit a signal transmission stop request to the first TRP (S1430). If it is determined that the first TRP does not participate in mTRP transmission, the terminal may transmit a transmission beam set recovery request to the second TRP group or a coordinating TRP among the TRPs belonging to the second TRP group (S1440). If it is determined that the first TRP does not participate in mTRP transmission, the terminal may change its optimal reception beam to the optimal reception beam set before the first TRP participated in mTRP (S1450). The order in which the operations S1430, S1440, and S1450 are performed may be interchanged.

[0188] Figure 14c is a flowchart illustrating an embodiment of a terminal that operates mTRP transmission.

[0189] Referring to FIG. 14C, the terminal can measure the performance (e.g., RSRP, RSRQ, or CQI) of a beam (hereinafter referred to as a “combined beam”) in which beams received from a second TRP group that performs mTRP transmission for the terminal are combined in a coordinated manner at the terminal. The terminal can check whether the RSRP of the combined beam exceeds a predefined threshold. If it is confirmed that the RSRP of the combined beam does not exceed the predefined threshold, the terminal can transmit a message to the second TRP group or a coordinating TRP among the TRPs belonging to the second TRP groups, requesting that a TRP, a candidate for mTRP transmission participation, participate in the mTRP transmission performed by the second TRP group. The second TRP group or the coordinating TRP among the TRPs belonging to the second TRP group that received the above-described message can transmit a message to some TRPs among the pre-determined candidate TRPs for mTRP transmission, requesting that they participate in the mTRP transmission.

[0190] The operations of the method according to the present disclosure can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes any type of recording device that stores information readable by a computer system. Furthermore, a computer-readable recording medium can be distributed across network-connected computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0191] Additionally, the computer-readable recording medium may include hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. The program instructions may include not only machine language codes produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter, etc.

[0192] While some aspects of the present disclosure have been described in the context of a device, they may also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described as a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, at least one or more of the most significant method steps may be performed by such a device.

[0193] A programmable logic device (e.g., a field-programmable gate array) may be used to perform some or all of the functions of the methods described in the present disclosure. The field-programmable gate array may operate in conjunction with a microprocessor to perform one of the methods described in the present disclosure. In general, the methods are preferably performed by some hardware device.

[0194] Although the present disclosure has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present disclosure without departing from the spirit and scope of the present disclosure as set forth in the claims below.

Claims

1. As a terminal method, A step of determining a type of electromagnetic field between a first TRP group including a first TRP (transmission and reception point) and one or more second TRP(s) and the terminal; After determining the type of the electromagnetic field, a step of setting a first beam pair set including the transmission beams of the first TRP group and the first reception beam of the terminal; A step of performing a comparison between the performance of the first reception beam measured based on the first beam pair set and the performance of the second reception beam measured based on the second beam pair set including the transmission beams of the second TRP group including the one or more second TRP(s) and the second reception beam of the terminal, depending on the type of the electromagnetic field; and A step of determining whether the first TRP participates in mTRP (multiple transmission and reception points) transmission to the terminal based on the above comparison, Each of the second TRP group and the first TRP group performs mTRP transmission to the terminal based on each of the second beam pair set and the first beam pair set, Terminal method.

2. In claim 1, A step of receiving first information for determining the type of electromagnetic field between the first TRP group and the terminal before determining the type of electromagnetic field between the first TRP group and the terminal; Further comprising a step of determining the type of electromagnetic field between the first TRP and the terminal based on the first information, The first information includes at least one of information on a pattern of PT (phase tracking)-RS (reference signals) received from the first TRP, information on a time interval in which the PT-RSs are transmitted, information on a frequency band used for communication between the first TRP and the terminal, information on a maximum length of an antenna array belonging to the first TRP, information on a distance between the first TRP and the terminal, or an identifier of the first TRP. Terminal method.

3. In claim 2, A step of receiving PT-RSs from the first TRP before determining the type of electromagnetic field between the first TRP and the terminal; Further comprising a step of determining the maximum phase difference between PT-RSs received by antenna elements belonging to the terminal based on the PT-RSs, The type of electromagnetic field between the first TRP and the terminal is determined based on the maximum phase difference. Terminal method.

4. In claim 2, Before determining the type of electromagnetic field between the first TRP and the terminal, the method further includes a step of determining a Rayleigh distance between the first TRP and the terminal based on at least one of the first information or information on the maximum length of an antenna array belonging to the terminal. The type of electromagnetic field between the first TRP and the terminal is determined based on the Rayleigh distance. Terminal method.

5. In claim 2, The step of setting the first beam pair set is: A step of transmitting information on the type of electromagnetic field between the first TRP and the terminal to the first TRP; A step of forming reception beams of the terminal for a transmission beam of the first TRP determined through beam sweeping of the first TRP in response to information on the type of electromagnetic field between the first TRP and the terminal; and A step of setting a first beam pair set including a beam pair composed of a reception beam determined based on RSRP values ​​of the reception beams among the reception beams and a transmission beam of the first TRP, Terminal method.

6. In claim 2, The step of setting the first beam pair set is: A step of transmitting information on the type of electromagnetic field between the first TRP and the terminal to the first TRP; forming reception beams of the terminal for transmission beams determined through joint beam adjustment of the first TRP group in response to information on the type of electromagnetic field between the first TRP and the terminal; and A step of setting the first beam pair set, which includes a beam pair composed of the first reception beam determined based on the RSRP values ​​of the reception beams among the reception beams and the transmission beam of each of the TRPs belonging to the first TRP group, Terminal method.

7. In claim 1, If it is determined that the first TRP participates in mTRP transmission for the terminal, further comprising a step of terminating a beam management procedure with the first TRP group, Terminal method.

8. In claim 1, Further comprising the step of transmitting a request to stop signal transmission to the first TRP when it is determined that the first TRP does not participate in mTRP transmission to the terminal. Terminal method.

9. In claim 1, Further comprising a step of transmitting a transmission beam set recovery request signal to a coordinating TRP among the second TRP group when it is determined that the first TRP does not participate in mTRP transmission for the terminal, The above transmission beam set recovery request signal is a signal requesting that the first transmission beam set of the second TRP group be changed to the second transmission beam set set before the first TRP participates in mTRP transmission. Terminal method.

10. In claim 1, If it is determined that the first TRP does not participate in mTRP transmission for the terminal, further comprising a step of changing the first reception beam of the terminal to the second reception beam of the terminal set before the first TRP group performs mTRP transmission. Terminal method.

11. In claim 8, A step of performing measurement on at least one of the RSRP value of a combined beam in which beams received from the second TRP group are combined according to a set period based on an mTRP timer set in the terminal or a distance moved by the terminal during the period; Further comprising a step of transmitting a participation request message to the adjustment TRP among the second TRP group based on the above measurement, The above participation request message is a message requesting that the first TRP participate in mTRP transmission. Terminal method.

12. As a method of the first TRP (transmission and reception point), A step of transmitting first information to the terminal for determining the type of electromagnetic field between the first TRP and the terminal; A step of receiving information on the type of electromagnetic field between the first TRP and the terminal determined based on the first information from the terminal; and A step of performing beam sweeping using transmission beams corresponding to the type of the electromagnetic field for the terminal in response to information on the type of the electromagnetic field; Method of the 1st TRP.

13. In claim 11, After transmitting the above first information, it further includes a step of transmitting PT (phase tracking)-RS (reference signals) to the terminal, The first information includes at least one of information on the pattern of the PT-RSs, information on the time interval in which the PT-RSs are transmitted, information on the frequency band used for communication between the first TRP and the terminal, information on the maximum length of the antenna array belonging to the first TRP, or an identifier of the first TRP. Method of the 1st TRP.

14. In claim 11, A step of receiving RSRP values ​​of the transmission beams formed by the beam sweeping from the terminal; and Further comprising a step of determining an optimal transmission beam for performing communication with the terminal based on the RSRP values. Method of the 1st TRP.

15. In claim 14, A step of receiving a request to stop signal transmission from the terminal and stopping communication with the terminal according to the request to stop signal transmission; A step of receiving an mTRP transmission participation request signal from a coordinating TRP among the second TRP group performing mTRP transmission to the terminal after stopping communication with the terminal; and Further comprising a step of performing mTRP transmission for the terminal in cooperation with the second TRP group according to the mTRP transmission participation request signal. Method of the 1st TRP.

16. As a terminal, Contains at least one processor, At least one processor of the terminal, Determining the type of electromagnetic field between a first TRP group including a first TRP (transmission and reception point) and one or more second TRP(s) and the terminal; After determining the type of the electromagnetic field, a first beam pair set including the transmission beams of the first TRP group and the first reception beam of the terminal is set; According to the type of the electromagnetic field, a comparison is performed between the performance of the first reception beam measured based on the first beam pair set and the performance of the second reception beam measured based on the second beam pair set including the transmission beams of the second TRP group including the one or more second TRP(s) and the second reception beam of the terminal; and Based on the above comparison, causing the first TRP to determine whether to participate in mTRP (multiple transmission and reception points) transmission to the terminal, Each of the second TRP group and the first TRP group performs mTRP transmission to the terminal based on each of the second beam pair set and the first beam pair set, Terminal.

17. In claim 16, At least one processor of the terminal, If it is determined that the first TRP does not participate in mTRP transmission to the terminal, further causing the first TRP to transmit a request to stop signal transmission, Terminal.

18. In claim 16, At least one processor of the terminal, If it is determined that the first TRP does not participate in the mTRP transmission for the terminal, it further causes a transmission beam set recovery request signal to be transmitted to a coordinating TRP among the second TRP group, The above transmission beam set recovery request signal is a signal requesting that the first transmission beam set of the second TRP group be changed to the second transmission beam set set before the first TRP participates in mTRP transmission. Terminal.

19. In claim 16, At least one processor of the terminal, If it is determined that the first TRP does not participate in the mTRP transmission for the terminal, further causing the first reception beam of the terminal to be changed to the second reception beam of the terminal set before the first TRP group performs the mTRP transmission, Terminal.

20. In claim 17, At least one processor of the terminal, Performing measurement of at least one of the RSRP value of a combined beam in which beams received from the second TRP group are combined according to a set period based on the mTRP timer set in the terminal or the distance moved by the terminal during the period; and Further causing a participation request message to be sent to the adjusting TRP among the second TRP group based on the above measurement, The above participation request message is a message requesting that the first TRP participate in mTRP transmission. Terminal.

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