Method and device for updating TCI state in multi-TRP communication

Abstract

Disclosed are a method and device for updating a TCI state in multi-TRP communication. A method performed by a UE according to the present disclosure comprises the steps of: receiving, from a first TRP, DCI including PDSCH scheduling information, a TCI field, and a TCI selection field; updating a TCI state for one of the first TRP and a second TRP on the basis of the TCI field and the configuration of the TCI selection field; and receiving a PDSCH according to the PDSCH scheduling information from the first TRP and the second TRP on the basis of the updated TCI state and the existing TCI state.

Description

Method and device for updating TCI status in multi-TRP communication

[0001] The present disclosure relates to communication technology, and more particularly, to a technology for updating a transmission configuration indicator (TCI) state in a communication system including multiple transmission and reception points (TRPs).

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

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

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

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

[0006] In mTRP communication, transmission configuration indicator (TCI) status updates can be performed for all mTRPs. Depending on the communication situation, a TCI status update for one mTRP may be required. However, mTRP communication currently does not support TCI status updates for a single TRP, making it impossible to perform TCI status updates that take communication conditions into account. Therefore, methods for updating the TCI status for a single TRP in mTRP communication are needed.

[0007] The purpose of the present disclosure to solve the above problems is to provide a method and device for updating a transmission configuration indicator (TCI) state in a communication system including multiple transmission and reception points (TRPs).

[0008] According to embodiments of the present disclosure for achieving the above object, a method of a UE (user equipment) includes the steps of receiving DCI (downlink control information) including PDSCH (physical downlink shared channel) scheduling information, a transmission configuration indicator (TCI) field, and a TCI selection field from a first transmission and reception point (TRP), performing a TCI state update for one of the first TRP and a second TRP based on settings of the TCI field and the TCI selection field, and receiving a PDSCH according to the PDSCH scheduling information from the first TRP and the second TRP based on the updated TCI state and the existing TCI state.

[0009] The step of performing an update of a TCI state for the above one TRP may include a step of updating a first TCI state among two TCI states to a TCI state indicated by the TCI field when the TCI selection field is set to a first value, and a step of updating a second TCI state among two TCI states to a TCI state indicated by the TCI field when the TCI selection field is set to a second value.

[0010] The method may further include a step of receiving a message including information indicating enablement or disablement of use of the DCI indicating a beam change before receiving the DCI, wherein when use of the DCI indicating a beam change is enabled, an update of a TCI state for the one TRP may be performed based on information included in the DCI, and when use of the DCI indicating a beam change is disabled, an update of a TCI state for both the first TRP and the second TRP may be performed based on information included in the DCI.

[0011] The DCI may further include a beam change indicator, and when the beam change indicator is set to a first value, an update of the TCI state for both the first TRP and the second TRP may be performed, and when the beam change indicator is set to a second value, an update of the TCI state for the one TRP may be performed.

[0012] When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates one TCI state among the two TCI states, the update of the TCI state for the one TRP can be performed based on the one TCI state indicated by the TCI selection field.

[0013] When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates a first TCI state among the two TCI states, a previous TCI state corresponding to the first TCI state can be updated to the first TCI state indicated by the TCI selection field.

[0014] When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates a second TCI state among the two TCI states, a previous TCI state corresponding to the second TCI state can be updated to the second TCI state indicated by the TCI selection field.

[0015] That the DCI includes the beam change information can be indicated to the UE by signaling.

[0016] Existing fields included in the above DCI can be reused for the beam change indicator.

[0017] According to embodiments of the present disclosure for achieving the above object, a method of a UE includes the steps of receiving, from a first TRP, DCI including PUSCH scheduling information, a TCI field, and a sounding reference signal resource indicator (SRI) indicating at least one TCI state, performing an update of a TCI state for one of the first TRP and a second TRP based on a setting of the TCI field and the SRI, and transmitting a PUSCH according to the PUSCH scheduling information to the first TRP and the second TRP based on the updated TCI state and the existing TCI state.

[0018] The step of updating the TCI state for the above one TRP may include the step of updating a first TCI state among the two TCI states to a TCI state indicated by the TCI field when the SRI is set to a first value, and the step of updating a second TCI state among the two TCI states to a TCI state indicated by the TCI field when the SRI is set to a second value.

[0019] The method may further include receiving a message including information indicating enabling or disabling use of the DCI indicating a beam change before receiving the DCI, wherein when use of the DCI indicating a beam change is enabled, an update of a TCI state for the one TRP may be performed based on information included in the DCI, and when use of the DCI indicating a beam change is disabled, an update of a TCI state for both the first TRP and the second TRP may be performed based on information included in the DCI.

[0020] That the DCI includes the TCI field can be indicated to the UE by signaling.

[0021] According to embodiments of the present disclosure for achieving the above object, a UE includes at least one processor, wherein the at least one processor causes the UE to receive DCI including PDSCH scheduling information, a TCI field, and a TCI selection field from a first TRP, update a TCI state for one of the first TRP and the second TRP based on settings of the TCI field and the TCI selection field, and receive a PDSCH according to the PDSCH scheduling information from the first TRP and the second TRP based on the updated TCI state and the existing TCI state.

[0022] In the step of performing an update of a TCI state for the one TRP, the at least one processor may cause the UE to update a first TCI state among the two TCI states to a TCI state indicated by the TCI field when the TCI selection field is set to a first value, and to update a second TCI state among the two TCI states to a TCI state indicated by the TCI field when the TCI selection field is set to a second value.

[0023] The at least one processor may further cause the UE to receive a message including information indicating enabling or disabling use of the DCI indicating a beam change before reception of the DCI, wherein when use of the DCI indicating a beam change is enabled, an update of a TCI state for the one TRP may be performed based on information included in the DCI, and when use of the DCI indicating a beam change is disabled, an update of a TCI state for both the first TRP and the second TRP may be performed based on information included in the DCI.

[0024] The DCI may further include a beam change indicator, and when the beam change indicator is set to a first value, an update of the TCI state for both the first TRP and the second TRP may be performed, and when the beam change indicator is set to a second value, an update of the TCI state for the one TRP may be performed.

[0025] When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates one TCI state among the two TCI states, the update of the TCI state for the one TRP can be performed based on the one TCI state indicated by the TCI selection field.

[0026] When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates a first TCI state among the two TCI states, a previous TCI state corresponding to the first TCI state can be updated to the first TCI state indicated by the TCI selection field.

[0027] When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates a second TCI state among the two TCI states, a previous TCI state corresponding to the second TCI state can be updated to the second TCI state indicated by the TCI selection field.

[0028] According to the present disclosure, in a procedure for transmitting and receiving a physical downlink shared channel (PDSCH) according to mTRP (multiple transmission and reception points) communication based on a single DCI (downlink control information), a terminal can update a transmission configuration indicator (TCI) state for one of a first TRP and a second TRP based on information included in DL (downlink) DCI, and can receive a PDSCH from the first TRP and the second TRP based on the updated TCI state and an existing TCI state. In a procedure for transmitting and receiving a physical uplink shared channel (PUSCH) according to mTRP communication based on a single DCI, the terminal can update a TCI state for one of the first TRP and the second TRP based on information included in UL (uplink) DCI, and can transmit a PUSCH to the first TRP and the second TRP based on the updated TCI state and an existing TCI state. Therefore, in mTRP communication, the TCI status for one TRP can be updated, which can improve communication performance.

[0029] Figure 1 is a conceptual diagram illustrating embodiments of a communication system.

[0030] Figure 2 is a block diagram illustrating embodiments of communication nodes constituting a communication system.

[0031] Figure 3 is a block diagram illustrating embodiments of communication nodes that perform communication.

[0032] Figure 4a is a block diagram illustrating embodiments of a transmission path.

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

[0034] Figure 5 is a conceptual diagram illustrating embodiments of system frames in a communication system.

[0035] Figure 6 is a conceptual diagram illustrating embodiments of subframes in a communication system.

[0036] Figure 7 is a conceptual diagram illustrating embodiments of slots in a communication system.

[0037] Figure 8 is a conceptual diagram illustrating embodiments of time-frequency resources in a communication system.

[0038] FIG. 9 is a flowchart illustrating embodiments of a beam change method for one TRP in a PDSCH transmission / reception procedure according to single DCI-based mTRP communication.

[0039] FIG. 10 is a flowchart illustrating embodiments of a beam change method for one TRP in a PUSCH transmission / reception procedure according to single DCI-based mTRP communication.

[0040] 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.

[0041] 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.

[0042] 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.”

[0043] 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.”

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] In the present disclosure, signaling may be at least one of upper layer signaling, MAC signaling, or PHY (physical) signaling. A message used for upper layer signaling may be referred to as an "upper layer message" or an "upper layer signaling message." A message used for MAC signaling may be referred to as a "MAC message" or a "MAC signaling message." A message used for PHY signaling may be referred to as a "PHY message" or a "PHY signaling message." Upper layer signaling may refer to a transmission and reception operation of system information (e.g., a master information block (MIB), a system information block (SIB)) and / or a radio resource control (RRC) message. MAC signaling may refer to a transmission and reception operation of a MAC control element (CE). PHY signaling may refer to a transmission and reception operation of control information (e.g., downlink control information (DCI), uplink control information (UCI), sidelink control information (SCI)).

[0051] 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.”

[0052] The communication networks to which the embodiments are applied are not limited to those described below, and the embodiments may be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, the term "communication network" may be used interchangeably with the term "communication system."

[0053] Figure 1 is a conceptual diagram illustrating embodiments of a communication system.

[0054] 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.

[0055] A plurality of communication nodes (110 to 130) can support a communication protocol specified in the 3rd generation partnership project (3GPP) standard (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.). 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.

[0056] Figure 2 is a block diagram illustrating embodiments of communication nodes constituting a communication system.

[0057] 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.

[0058] 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).

[0059] 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).

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] Figure 3 is a block diagram illustrating embodiments of communication nodes that perform communication.

[0067] 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).

[0068] 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.

[0069] 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).

[0070] 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).

[0071] 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).

[0072] 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).

[0073] 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).

[0074] 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.

[0075] FIG. 4a is a block diagram illustrating embodiments of a transmission path, and FIG. 4b is a block diagram illustrating embodiments of a reception path.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] Figure 5 is a conceptual diagram illustrating embodiments of a system frame in a communication system.

[0083] 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.

[0084] 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."

[0085] Figure 6 is a conceptual diagram illustrating embodiments of subframes in a communication system.

[0086] 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.

[0087] Figure 7 is a conceptual diagram illustrating embodiments of slots in a communication system.

[0088] Referring to FIG. 7, a single slot may include one or more symbols. A single slot illustrated in FIG. 7 may include 14 symbols. The length of a slot may vary depending on the number and length of symbols contained in the slot. Alternatively, the length of a slot may vary depending on numerology.

[0089] 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.

[0090]

[0091] 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.

[0092] 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.

[0093] 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."

[0094] 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.

[0095] 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.

[0096] Figure 8 is a conceptual diagram illustrating embodiments of time-frequency resources in a communication system.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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).

[0102] The search space information may include a coreset identifier (ID) associated with the search space, a period of PDCCH monitoring, and / or an offset. Each of the PDCCH monitoring period and offset may 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.

[0103] 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).

[0104] Meanwhile, a communication system (e.g., NR communication system, 5G communication system, 6G communication system) may support usage scenarios such as enhanced Mobile BroadBand (eMBB), Ultra Reliable Low Latency Communication (URLLC), and massive Machine Type Communication (mMTC). A communication system (e.g., a communication network) may support transmission and reception point (TRP) technology (e.g., multiple TRP (mTRP) technology and / or single TRP (sTRP) technology). A communication system supporting the TRP technology may be referred to as a TRP system (e.g., mTRP system and / or sTRP system). In the present disclosure, TRP may have a meaning including sTRP and / or mTRP, and TRP may mean sTRP or mTRP depending on the context. TRP may mean an antenna set, an antenna group, and / or an antenna array. A TRP may be associated with a CORESET and / or a beam (e.g., a beam group).

[0105] mTRP technology may fall under the category of MIMO technology. mTRP may have characteristics (e.g., level characteristics) of macrocells, small cells, picocells, and / or femtocells. mTRP can perform data transmission for a single terminal. In a channel (e.g., a link) with uneven channel conditions due to obstacles and / or interference, mTRP can attenuate the effects of the obstacles and / or interference. mTRP can improve the data transmission rate for terminals located at cell edge areas.

[0106] mTRP-based communication can be performed using either coherent joint transmission (CJT) or non-CJT (NCJT) methods. In CJT, the base station can obtain channel information between each mTRP and the terminal and perform preprocessing on the data based on this channel information. In this case, the overhead associated with transmitting channel information may increase, and synchronization constraints between TRPs may arise. In NCJT, the base station may not need to know the channel information between each mTRP and the terminal. mTRPs can transmit data to the terminal without performing preprocessing operations such as phase compensation. The complexity of NCJT may be lower than that of CJT.

[0107] NCJT-based mTRP communication can be performed based on a single DCI scheme or a multiple DCI scheme. In the single DCI scheme, PDSCHs transmitted by an mTRP can be scheduled by a single DCI. A single DCI can be transmitted by one TRP among the mTRPs. In the multiple DCI scheme, the PDSCHs transmitted by each TRP can be scheduled by the DCI transmitted by each TRP. For example, a first PDSCH transmitted by a first TRP can be scheduled by a first DCI transmitted by the first TRP, and a second PDSCH transmitted by a second TRP can be scheduled by a second DCI transmitted by the second TRP. In other words, multiple PDSCHs can be scheduled using multiple DCIs.

[0108] In a single SCI scheme, a terminal can expect to receive PDSCHs transmitted by different TRPs over the same time and frequency resources and across different layers. Alternatively, the terminal can expect to receive PDSCHs transmitted by different TRPs over the same frequency resources and across the same layer but across different time resources (e.g., across different time domains). Alternatively, the terminal can expect to receive PDSCHs transmitted by different TRPs over the same time resources and across the same layer but across different frequency resources (e.g., across different frequency domains).

[0109] In a multi-DCI scheme, scheduling of PDSCHs for each TRP can be performed by a separate DCI. The PDSCHs scheduled by multiple DCIs may fully overlap or partially overlap. Alternatively, the PDSCHs scheduled by multiple DCIs may not overlap. In both single-DCI and multi-DCI schemes, the DCI may include transmission configuration indicator (TCI) status information for the PDSCH.

[0110] The indication / setting of the TCI state for a terminal may be interpreted as the indication / setting of a beam (e.g., a transmit beam and / or a receive beam). In other words, the TCI state may have a meaning corresponding to the beam. From the perspective of DL (downlink) communication, the setting of the TCI state may mean the setting of QCL (quasi co-location). From the perspective of UL (uplink) communication, the setting of the TCI state may mean the setting of a spatial filter. The unified TCI state may indicate (e.g., set) a common beam regardless of DL communication and UL communication. Alternatively, the unified TCI state may indicate (e.g., set) a common beam for each of DL communication and UL communication. The unified TCI may be referred to as UTCI.

[0111] Enhancements (e.g., PDCCH enhancements) may be implemented to improve the reliability and / or robustness of mTRP communications. Deployment scenarios for PDCCH enhancements can be categorized into single frequency network (SFN) and non-SFN scenarios.

[0112] In the SFN scheme, different TRPs or different panels can transmit the same PDCCH using the same resources (e.g., the same time resources, the same frequency resources, and / or the same spatial resources). In other words, all TRPs or all panels can transmit the same PDCCH using the same DMRS configuration, the same DMRS location, and / or the same DMRS sequence. At this time, the TCI states for the reception perspective of the TRPs or panels can be implicitly set differently. The above embodiment can be performed based on multiple TCI states of the CORESET. There may be synchronization constraints for ideal or near-ideal backhaul between TRPs.

[0113] In the NSFN scheme, the PDCCH generated from each TRP can be multiplexed in the time domain and / or frequency domain, and the multiplexed PDCCH can be transmitted to the terminal. The scheme may be an mTRP-based PDCCH repetition scheme. In the NSFN scheme, the same number of bits as the encoded bits transmitted through one PDCCH generated from each TRP can be divided for each TRP, and the bits (e.g., encoded bits) for each TRP can be transmitted through different PDCCH candidates. The scheme may be an sTRP-based PDCCH transmission scheme.

[0114] In the mTRP-based PDCCH repetition scheme, the PDCCH can be repeatedly generated as many times as the number of TRPs, and the PDCCH can be transmitted in the same search space (e.g., search spaces having the same index) within different search space sets having the same number of PDCCH candidates. At this time, the search space sets can exist within the same CORESET or different CORESETs. Since one TCI state can be associated with each CORESET, when the PDCCH is transmitted in different search spaces within the same CORESET, only one TCI state can be indicated (e.g., set) for the PDCCHs transmitted in the different search spaces. In this case, the UE can receive the PDCCH from one TRP at a specific time.

[0115] When a PDCCH is transmitted in the same search space within different CORESETs, the UE can implicitly expect to receive the PDCCH from either the sTRP or the mTRP, depending on the number of TCI states (e.g., TCI states indicated or configured by the base station). In this case, a single PDCCH can be split as many times as the number of TRPs, and the split PDCCHs can be transmitted on different PDCCH candidates. At this time, the aggregation level and the combined aggregation level can be the same. In the above embodiment, the PDCCH candidates can be assigned to different CORESETs. The payload size for the final distributed PDCCH combination can be the same as the payload size of the PDCCH transmitted in the sTRP. Therefore, in terms of decoding complexity, the sTRP-based PDCCH transmission scheme can be advantageous over the mTRP-based PDCCH repetition scheme.

[0116] A terminal can perform mTRP communication or sTRP communication with a base station. mTRP communication between the terminal and the base station can be performed through an mTRP associated with the base station. sTRP communication between the terminal and the base station can be performed through an sTRP associated with the base station. mTRP communication may be referred to as first TRP communication, and sTRP communication may be referred to as second TRP communication. Alternatively, mTRP communication may be referred to as second TRP communication, and sTRP communication may be referred to as first TRP communication. "The terminal performs first TRP communication with the base station" may mean "the terminal performs mTRP communication or sTRP communication with the base station through one or more TRPs associated with the base station." "The terminal performs second TRP communication with the base station" may mean "the terminal performs sTRP communication or mTRP communication with the base station through one or more TRPs associated with the base station."

[0117] In a communication system, integrated TCI can be supported. A base station can transmit information about a pool (e.g., a list) of TCI states to a terminal using RRC signaling. The terminal can receive information about a pool (e.g., a list) of TCI states through RRC signaling from the base station. The base station can set type information about the TCI state to the terminal. The type information can be a joint DL / UL beam indication or a separate DL / UL beam indication. A joint DL / UL beam indication can be referred to as a 'joint indication or joint type.' An independent DL / UL beam indication can be referred to as an 'independent indication or independent type.'

[0118] When a joint type (e.g., joint indication) is set, TCI states (e.g., one TCI state) for DL ​​and UL may be set. In other words, DL TCI state setting and UL TCI state setting may be the same. The UE may expect that the TCI state indicated by the information element included in the PDSCH configuration information applies to both DL (e.g., DL signal / channel) and UL (e.g., UL signal / channel). The signal / channel may refer to a signal and / or a channel. When an independent type (e.g., independent indication) is set, TCI states for DL ​​and UL may be set respectively. In other words, DL TCI state setting may be distinguished from UL TCI state setting. The UE may expect that the UL TCI state indicated by the information element included in the UL BWP configuration information applies to UL (e.g., UL signal / channel). The UL signal / channel may include a PUSCH, a PUCCH, and / or an SRS.

[0119] After the pool (e.g., pool list) for TCI states is configured (e.g., indicated) by RRC signaling, the base station can use DCI (e.g., DCI signaling) to indicate the TCI state (e.g., application of the TCI state). Due to the constraint of the DCI size (e.g., bits in the DCI field), the base station can preferentially activate candidate TCI state(s) using MAC signaling (e.g., MAC CE signaling). In other words, as many (e.g., maximum number) candidate TCI state(s) as can be indicated (e.g., configured) via DCI can be preferentially activated by MAC CE.

[0120] For the activated candidate TCI state(s), the DCI may contain code points corresponding to a single TCI state or two TCI states, depending on the TCI state type (e.g., joint type or independent type). If the joint type is set, the code points corresponding to a single TCI state may be conveyed by the DCI. If the independent type is set, the code points corresponding to two TCI states may be conveyed by the DCI.

[0121] Meanwhile, when an integrated TCI state is used, the number of combinations of TCI states activated by MAC CE among the TCI states set by RRC signaling can be eight. A combination of TCI states may be referred to as a TCI state combination. A TCI state combination may be a joint TCI state or a DL / UL TCI state applied to two TRPs. Even when only a beam change for one TRP is required in a single DCI-based mTRP operation, a TCI state for the mTRP (e.g., two TRPs) may be indicated to the UE. When eight TCI state combinations are used, a limitation in the beam change procedure for one TRP in mTRP communication may occur due to the insufficient number of TCI state combinations. An efficient method for beam changing for one TRP in a single DCI-based mTRP communication is needed.

[0122] When an integrated TCI state is used, eight TCI state combinations can be configured / activated by RRC signaling and MAC CE. One of the eight TCI state combinations can be indicated by a TCI field included in the DCI. The size of the TCI field can be 3 bits. The TCI field can indicate two joint TCI states or two DL / UL TCI states. The two TCI states indicated by the TCI field can mean TCI states to be applied to DL and / or UL for two TRPs. In the present disclosure, a TCI state can be interpreted as a joint TCI state, a joint / DL TCI state, a joint / UL TCI state, a DL TCI state, a UL TCI state, or a DL / UL TCI state depending on the context.

[0123] When a combination of TCI states for two TRPs is always indicated, and only a beam (e.g., TCI state) change is required for one TRP in a single DCI-based mTRP communication, the beam change operation for one TRP may not be performed. In other words, the indication of a combination of TCI states for two TRPs may result in restrictions on various beam configurations for one TRP. When eight TCI state combinations are used, mapping various beams for one TRP in mTRP communication may not be possible. Methods are needed to efficiently change the beam for one TRP in a single DCI-based mTRP communication. A beam may have the same meaning as a TCI state.

[0124] [Example #1] Method for changing a beam (e.g., TCI state) for one TRP in a PDSCH transmission / reception procedure according to mTRP communication based on a single DCI

[0125] DCI can schedule PDSCH transmission. DCI that schedules PDSCH transmission can be referred to as scheduling DCI or DL ​​DCI. DCI can be interpreted as scheduling DCI or DL ​​DCI depending on the context. DL DCI can be DCI format 1_0, DCI format 1_1, DCI format 1_2, or DCI format 1_3. DL DCI can include TCI status information (e.g., TCI field and / or TCI selection field).

[0126] The TCI field included in the DL DCI can indicate two TCI states (e.g., two joint TCI states or two DL / UL TCI states). The DL DCI can include a TCI selection field, and the size of the TCI selection field can be 2 bits. The TCI selection field set to 00 can indicate that the first indicated TCI is applied for PDSCH reception (e.g., PDSCH transmission). The TCI selection field set to 01 can indicate that the second indicated TCI is applied for PDSCH reception (e.g., PDSCH transmission). The TCI selection field set to 10 can indicate that all indicated TCIs (e.g., the first indicated TCI and the second indicated TCI) are applied for PDSCH reception (e.g., PDSCH transmission).

[0127] DL DCI may include a beam change indicator, and the size of the beam change indicator may be 1 bit. The beam change indicator may be interpreted as a TCI update indicator. Based on the beam change indicator, the TCI field, and / or the TCI selection field included in the DL DCI, a beam change (e.g., a TCI status update) for one TRP may be indicated. A beam change indicator set to a first value (e.g., 0) may indicate that a beam change operation (e.g., a TCI update operation) for one TRP is not performed. A beam change indicator set to a second value (e.g., 1) may indicate that a beam change operation (e.g., a TCI update operation) for one TRP is performed.

[0128] When the beam change indicator is set to the first value, the terminal can perform a PDSCH reception operation (e.g., a conventional PDSCH reception operation) based on the TCI state(s) indicated by the TCI field and / or the TCI selection field included in the DL DCI. In other words, the terminal can interpret the TCI state(s) indicated by the TCI field and / or the TCI selection field included in the DL DCI as the TCI state(s) for the mTRP, and can receive the PDSCH from the mTRP. The TCI states for the mTRP can be updated based on the TCI field and / or the TCI selection field, and the terminal can receive the PDSCH from the mTRP based on the updated TCI states.

[0129] When the beam change indication is set to the second value, the terminal can interpret the TCI state(s) indicated by the TCI field and / or the TCI selection field included in the DL DCI as the TCI state(s) for one TRP. In other words, the terminal can interpret the TCI state(s) indicated by the TCI field and / or the TCI selection field included in the DL DCI as indicating a beam change for one TRP. For example, when the TCI field indicates two TCI states and the TCI selection field indicates a first indicated TCI state among the two indicated TCI states, the terminal can update the previous TCI state corresponding to the first indicated TCI state to the TCI state indicated by the TCI field and / or the TCI selection field, and maintain the mTRP operation. In other words, the terminal can perform mTRP communication based on the updated TCI state and the existing TCI state. For another example, if the TCI field indicates two TCI states and the TCI selection field indicates a second indicated TCI state among the two indicated TCI states, the terminal can update the previous TCI state corresponding to the second indicated TCI state to the TCI state indicated by the TCI field and / or the TCI selection field, and maintain the mTRP operation. In other words, the terminal can perform mTRP communication based on the updated TCI state and the existing TCI state.

[0130] Based on the above-described method, in the reception procedure of a PDSCH scheduled by DL DCI, only a beam for one TRP can be changed, and the mTRP operation can be maintained. For two TCI states set in the reception procedure of a previous PDSCH, if the TCI selection field is set to 00, the terminal can update the first TCI state among the two TCI states to the first indicated TCI state among the two TCI states indicated by the TCI field, and perform a PDSCH reception operation based on the updated TCI state and the existing TCI state (e.g., a TCI state that has not been updated). For two TCI states set in the reception procedure of the previous PDSCH, if the TCI selection field is set to 01, the terminal can update the second TCI state among the two TCI states to the second indicated TCI state among the two TCI states indicated by the TCI field, and perform a PDSCH reception operation based on the updated TCI state and the existing TCI state (e.g., a TCI state that has not been updated). The existing settings for the remaining TCI states that have not been updated can be maintained. Therefore, a beam change operation (e.g., a TCI update operation) for one TRP can be performed.

[0131] If the TCI field indicates two TCI states, the TCI selection field is set to 10 or 11, and the beam change indicator is set to a first value (e.g., 0), the terminal can interpret the indication (e.g., setting) according to the TCI field, the TCI selection field, and the beam change indicator as a beam change indication for two TRPs. In this case, the terminal can update all existing TCI states to the TCI states indicated by the TCI field and maintain the mTRP operation.

[0132] A beam change for a TRP may be indicated by an RRC message and / or a MAC CE instead of a DL DCI. In this case, the DL DCI may not include a beam change indicator, and the RRC message and / or the MAC CE may indicate (e.g., configure) that the DL DCI is a DL DCI for a beam change for a TRP. In other words, the RRC message and / or the MAC CE may include information indicating that the use of the DL DCI indicating a beam change for a TRP is enabled or disabled. When the use of the DL DCI indicating a beam change for a TRP is enabled, the UE may change the beam for the TRP based on an indication of the TCI field and / or the TCI selection field included in the DL DCI. When the use of DL DCI indicating a beam change for a TRP is disabled, the terminal may change the beam for the mTRP based on the indication of the TCI field and / or the TCI selection field included in the DL DCI. Even in the above-described situation, the DL DCI may include a beam change indicator, and the update of the TCI status for the TRP(s) may be performed taking into account the beam change indicator.

[0133] The field for the beam change indicator may not be newly defined in the DL DCI. Existing fields included in the DL DCI (e.g., redundancy version (RV) field, new data indicator (NDI) field, MCS field, etc.) may be used (e.g., reused) to indicate a beam change for a TRP. The existing fields included in the DL DCI may implicitly indicate that the DL DCI is a DL DCI for a beam change (e.g., TCI status update) for a TRP. In other words, the beam change indicator may not be defined in the DL DCI.

[0134] A field for a beam change indicator in DL DCI may not be newly defined, and a TCI selection field having a size of 1 bit may be defined in DL DCI. The TCI selection field having a size of 1 bit may have the same or similar function as the beam change indicator. In other words, the TCI selection field having a size of 1 bit may indicate whether to perform a beam change operation for one TRP. Whether the DL DCI includes a beam change indicator, whether the DL DCI does not include a TCI selection field, whether the DL DCI includes a TCI selection field having a size of 1 bit, or whether the DL DCI includes a TCI selection field having a size of 2 bits may be indicated (e.g., configured) to the terminal by signaling (e.g., RRC signaling, MAC signaling).

[0135] A DL DCI including a TCI selection field having a size of 1 bit can indicate a beam change for one TRP. For two TCI states configured in a previous PDSCH reception procedure, if the TCI selection field having a size of 1 bit is set to 0, the terminal can update the first TCI state among the two TCI states to the first indicated TCI state among the two TCI states indicated by the TCI field, and perform a PDSCH reception operation based on the updated TCI state and the existing TCI state. For two TCI states configured in a previous PDSCH reception procedure, if the TCI selection field having a size of 1 bit is set to 1, the terminal can update the second TCI state among the two TCI states to the second indicated TCI state among the two TCI states indicated by the TCI field, and perform a PDSCH reception operation based on the updated TCI state and the existing TCI state. The existing configurations for the remaining TCI states that have not been updated can be maintained. Therefore, a beam change operation (e.g., an update operation of the TCI state) for one TRP can be performed.

[0136] In the above-described methods, a new indicator may be used instead of the TCI selection field having a size of 1 bit, and the size of the new indicator may be 1 bit. In this case, the TCI selection field may not be set in the DL DCI. The beam change for a TRP may be indicated by an RRC message and / or a MAC CE instead of the DL DCI. The RRC message and / or the MAC CE may indicate the beam change based on the TCI state setting for a specific TRP or mTRP. The above-described methods may also be applied when the size of the TCI field included in the DL DCI is changed.

[0137] The above-described methods can be modified or extended in various ways. A combination of the above-described methods can be used. For example, the TCI field in the DL DCI can be concatenated with other field(s), and the size of the TCI field can be increased using reserved bits. As the size of the TCI field increases, the number of TCI state combinations set / activated by the RRC message and MAC CE can increase. A change in the TCI field included in the DL DCI can be indicated (e.g., set) by the RRC message and / or the MAC CE. A bit (e.g., a field) indicating that the TCI field has a changed format can be added to the DL DCI.

[0138] When two TCI states are indicated by the TCI field, information (e.g., an indicator) indicating a beam change for a specific TRP may be included in the DL DCI. The TCI selection field may not be used to indicate a beam change for one TRP. In this case, a new field indicating a beam change for one TRP may be defined. Alternatively, an existing field in the DL DCI may be used to indicate a beam change for one TRP. The new field (or the existing field) may indicate a first TCI state or a second TCI state. The first TCI state may correspond to one of the two TCI states indicated by the TCI field (e.g., a first indicated TCI state), and the second TCI state may correspond to one of the two TCI states indicated by the TCI field (e.g., a second indicated TCI state). Based on the TCI field and the field indicating the TCI state to be updated (e.g., an indicator having a size of 1 bit or more), a beam change operation (e.g., an update operation of the TCI state) for one TRP in mTRP communication can be performed.

[0139] FIG. 9 is a flowchart illustrating embodiments of a beam change method for a single TRP in a PDSCH transmission / reception procedure according to single DCI-based mTRP communication. The embodiments illustrated in FIG. 9 can be performed based on the aforementioned embodiment #1.

[0140] Referring to FIG. 9, a first TRP may generate DL DCI including at least one of PDSCH scheduling information, a TCI field, a TCI selection field, a beam change indicator, or a 1-bit indicator (S910). The DL DCI may be generated by a base station connected to the first TRP, and the DL DCI may be shared with a second TRP performing mTRP communication. The DL DCI may include other information (e.g., MCS, RV, NDI, HARQ process number, etc.) in addition to the above-described information. The DL DCI may include information according to the above-described embodiment #1. The DL DCI generated in S910 may be a DL DCI indicating a beam change. If the use of a DL DCI indicating a beam change (e.g., an update of a TCI state) is enabled (e.g., permitted) by upper layer signaling, the first TRP may generate a DL DCI indicating a beam change.

[0141] In S920, the first TRP may transmit DL DCI to the terminal, and the terminal may receive the DL DCI from the first TRP. In single DCI-based mTRP communication, the DL DCI may be transmitted by one TRP. The terminal may check information included in the DL DCI. The terminal may update a TCI state (e.g., beam) for one of the first TRP and the second TRP based on information included in the DL DCI (e.g., a TCI field, a TCI selection field, a beam change indicator, and / or a 1-bit indicator) (S930). If the use of a DL DCI indicating a beam change is enabled (e.g., permitted) by upper layer signaling, the terminal may update the TCI state for one TRP based on the information included in the DL DCI. The terminal may update the TCI state for one TRP based on the method(s) according to the above-described embodiment #1. The first TRP and / or the second TRP may expect the TCI status for one TRP to be updated at the terminal. If the use of DL DCI indicating beam changes is disabled by higher-layer signaling, the terminal may update the TCI status for both the first TRP and the second TRP based on the information contained in the DL DCI.

[0142] In S940 and S950, the terminal may receive PDSCH from the first TRP and the second TRP based on the updated TCI state and the existing TCI state (i.e., the non-updated TCI state). PDSCH reception may be performed based on PDSCH scheduling information included in the DL DCI. For example, if the TCI state for the first TRP is updated, the terminal may receive PDSCH from the first TRP based on the updated TCI state (S940). If the TCI state for the second TRP is not updated, the terminal may receive PDSCH from the second TRP based on the existing TCI state (S950). In another example, if the TCI state for the first TRP is not updated, the terminal may receive PDSCH from the first TRP based on the existing TCI state (S940). If the TCI state for the second TRP is updated, the terminal may receive PDSCH from the second TRP based on the updated TCI state (S950).

[0143] In S940, if the TCI state for the first TRP is updated, the first TRP can transmit the PDSCH based on the updated TCI state, and if the TCI state for the first TRP is not updated, the first TRP can transmit the PDSCH based on the existing TCI state. In S950, if the TCI state for the second TRP is updated, the second TRP can transmit the PDSCH based on the updated TCI state, and if the TCI state for the second TRP is not updated, the second TRP can transmit the PDSCH based on the existing TCI state.

[0144] [Example #2] Method for changing a beam (e.g., TCI state) for one TRP in a PUSCH transmission / reception procedure according to single DCI-based mTRP communication

[0145] DCI can schedule PUSCH transmission. DCI for scheduling PUSCH transmission can be referred to as scheduling DCI or UL DCI. DCI can be interpreted as scheduling DCI or UL DCI depending on the context. UL DCI can be DCI format 0_0, DCI format 0_1, DCI format 0_2, or DCI format 0_3. Two TCI states (e.g., two joint / UL TCI states) can be indicated by MAC CE and / or DCI. DCI for scheduling PUSCH can include SRI (SRS resource indicator), and the size of SRI can be 2 bits. SRI can mean SRS resource set indicator. SRI can have the same or similar function as TCI selection field. In other words, SRI included in UL DCI can be used as TCI selection field for updating TCI state. An SRI set to 00 may indicate that the first TCI state (e.g., the first indicated TCI state) is applied for PUSCH transmission. An SRI set to 01 may indicate that the second TCI state (e.g., the second indicated TCI state) is applied for PUSCH transmission. An SRI set to 10 or 11 may indicate that two TCI states (e.g., the first indicated TCI state and the second indicated TCI state) are applied for PUSCH transmission.

[0146] The TCI state can be a joint / UL TCI state. The DL DCI indicating the two TCI states can be in a DCI format that includes a TCI field (e.g., DCI format 1_1 or DCI format 1_2). If the UL DCI does not include a TCI field, the two TCI states can be indicated by a DL DCI received before receiving the UL DCI.

[0147] In a PUSCH transmission / reception procedure according to mTRP communication, for a beam change operation (e.g., an update operation of a TCI state) for a TRP, the UL DCI including scheduling information of the PUSCH may include a TCI field. For the efficiency of the UL beam change, the UL DCI may include a TCI field. The TCI field included in the UL DCI may indicate new TCI states in the beam change procedure, and the SRI included in the UL DCI may indicate one or more TCI states among the TCI states indicated by the TCI field.

[0148] The RRC message and / or the MAC CE may indicate whether the UL DCI includes a TCI field. In other words, the RRC message and / or the MAC CE may indicate enabling or disabling the use of the UL DCI including the TCI field. "Enabling the use of the UL DCI including the TCI field" may mean "enabling the use of the UL DCI for beam switching." "Disabling the use of the UL DCI including the TCI field" may mean "disabling the use of the UL DCI for beam switching." Alternatively, an indicator indicating the presence or absence of a TCI field in the UL DCI may be included in the UL DCI, and the size of the indicator may be 1 bit. The TCI field included in the UL DCI may be operated in the same manner as the TCI field included in the DL DCI. For example, the size of the TCI field included in the UL DCI may be 3 bits. The mapping of code points to TCI fields included in UL DCI may be identical to the mapping of code points to TCI fields included in DL DCI.

[0149] When UL DCI includes a TCI field, the terminal may determine that beam changing operation for one TRP is supported in mTRP communication. When the TCI field included in the UL DCI indicates two TCI states and the SRI indicates a first indicated TCI state among the two indicated TCI states, the terminal may update a previous TCI state corresponding to the first indicated TCI state to a TCI state indicated by the TCI field and / or SRI, and maintain the mTRP operation. The terminal may perform mTRP communication based on the updated TCI state and the previous TCI state (e.g., a TCI state that has not been updated). For another example, if a TCI field included in UL DCI indicates two TCI states and an SRI indicates a second indicated TCI state among the two indicated TCI states, the terminal may update a previous TCI state corresponding to the second indicated TCI state to a TCI state indicated by the TCI field and / or SRI, and maintain mTRP operation. The terminal may perform mTRP communication based on the updated TCI state and the previous TCI state (e.g., a TCI state that has not been updated).

[0150] Based on the above-described method, in the transmission procedure of the PDSCH scheduled by the UL DCI, only the beam for one TRP can be changed, and the mTRP operation can be maintained. For the two TCI states set in the transmission procedure of the previous PUSCH, if the SRI is set to 00, the terminal can update the first TCI state among the two TCI states to the first indicated TCI state among the two TCI states indicated by the TCI field, and perform the PUSCH transmission operation based on the updated TCI state and the existing TCI state. For the two TCI states set in the transmission procedure of the previous PUSCH, if the SRI is set to 01, the terminal can update the second TCI state among the two TCI states to the second indicated TCI state among the two TCI states indicated by the TCI field, and perform the PUSCH transmission operation based on the updated TCI state and the existing TCI state. The existing configurations for the remaining TCI states that have not been updated can be maintained. Therefore, a beam change operation (e.g., an update operation of the TCI state) for one TRP can be performed.

[0151] In the above-described method, the SRI included in the UL DCI may not be used. Information indicating the first or second TCI state (e.g., an indicator with a size of 1 bit or more) may be defined, and the information may be included in the UL DCI. The configuration of fields within the UL DCI may be indicated by an RRC message and / or a MAC CE.

[0152] UL DCI including an indicator having a size of 1 bit (hereinafter referred to as “1-bit indicator”) may indicate a beam change (e.g., TCI update) for one TRP. The 1-bit indicator may mean a beam change indicator. For two TCI states set in a previous PUSCH transmission procedure, if the 1-bit indicator is set to 0, the UE may update the first TCI state among the two TCI states to the first indicated TCI state among the two TCI states indicated by the TCI field, and may perform a PUSCH transmission operation based on the updated TCI state and the existing TCI state. For two TCI states set in a previous PDSCH reception procedure, if the 1-bit indicator is set to 1, the UE may update the second TCI state among the two TCI states to the second indicated TCI state among the two TCI states indicated by the TCI field, and may perform a PUSCH transmission operation based on the updated TCI state and the existing TCI state. The existing settings for the remaining TCI states that have not been updated can be maintained. Therefore, a beam change operation (e.g., an update operation of the TCI state) for a single TRP can be performed.

[0153] When an update to the first or second TCI state is indicated by the SRI, the UE may perform a PUSCH transmission based on the SRI and the transmit precoding matrix indicator (TPMI) corresponding to the TCI state to be updated. The SRIs and TPMIs corresponding to the remaining TCI states that have not been updated may not be used. In other words, the SRIs and TPMIs corresponding to the remaining TCI states that have not been updated may be reserved. A UL DCI may include one SRI and one TPMI.

[0154] The above-described methods can be applied even when the size of the TCI field included in the UL DCI changes. The above-described methods can be modified or extended in various ways. A combination of the above-described methods can be used. For example, the TCI field included in the UL DCI can be operated independently from the TCI field included in the DL DCI. In other words, the TCI field included in the UL DCI can be a new field different from the TCI field included in the DL DCI. The UL DCI can include a TCI update field instead of the TCI field. The TCI update field can indicate two TCI states. The TCI state mapped to the code point of the TCI update field can be set by an RRC message and / or a MAC CE. The TCI update field can be a field indicating the setting of one or more TCI states.

[0155] As with the TCI field included in DL DCI, TCI states for two TRPs can be mapped to the TCI update field. One or more TCI states can be mapped to the TCI update field without mapping to a specific TRP. The TCI update field can be used for beam switching purposes. The TCI update field can indicate a specific set of TCI state candidates. A beam switching operation for a TRP based on the TCI update field can be performed as follows.

[0156] The TCI update field included in the UL DCI can indicate two TCI states. For the two TCI states set in the transmission procedure of the previous PUSCH, if the SRI is set to 00, the UE can update the first TCI state among the two TCI states to the first indicated TCI state among the two TCI states indicated by the TCI update field, and perform a PUSCH transmission operation based on the updated TCI state and the existing TCI state. For the two TCI states set in the transmission procedure of the previous PUSCH, if the SRI is set to 01, the UE can update the second TCI state among the two TCI states to the second indicated TCI state among the two TCI states indicated by the TCI update field, and perform a PDSCH reception operation based on the updated TCI state and the existing TCI state. The existing configurations for the remaining TCI states that have not been updated can be maintained. Therefore, a beam change operation for one TRP can be performed.

[0157] Instead of SRI, a 1-bit indicator indicating beam change for one TRP may be used. The 1-bit indicator may be included in UL DCI. For two TCI states configured in a previous PUSCH transmission procedure, if the 1-bit indicator is set to 0, the UE may update the first TCI state among the two TCI states to the first indicated TCI state among the two TCI states indicated by the TCI update field, and perform a PUSCH transmission operation based on the updated TCI state and the existing TCI state. For two TCI states configured in a previous PDSCH reception procedure, if the 1-bit indicator is set to 1, the UE may update the second TCI state among the two TCI states to the second indicated TCI state among the two TCI states indicated by the TCI update field, and perform a PUSCH transmission operation based on the updated TCI state and the existing TCI state. The existing configurations for the remaining TCI states that have not been updated may be maintained. Therefore, beam changing operations can be performed for one TRP.

[0158] When the TCI Update field indicates only one TCI state, the terminal can update the TCI state for a specific TRP based on the indicated TCI state. The specific TRP can be indicated by the SRI or a 1-bit indicator.

[0159] In a PUSCH transmission procedure based on single DCI-based mTRP communication, for beam changes for a TRP, the UL DCI may include a TCI field or a TCI update field indicating the TCI status. An SRI or a new indicator may be used to indicate a beam update for a specific TRP.

[0160] FIG. 10 is a flowchart illustrating embodiments of a beam change method for a single TRP in a PUSCH transmission / reception procedure based on single DCI-based mTRP communication. The embodiments illustrated in FIG. 10 can be performed based on the aforementioned embodiment #2.

[0161] Referring to FIG. 10, a first TRP may generate UL DCI including at least one of PUSCH scheduling information, a TCI field, an SRI, a TCI update field, a TCI selection field, or a 1-bit indicator (e.g., a beam change indicator) (S1010). The UL DCI may be generated by a base station connected to the first TRP, and the UL DCI may be shared with a second TRP that performs mTRP communication. The UL DCI may include other information (e.g., MCS, RV, NDI, HARQ process number, etc.) in addition to the above-described information. The UL DCI may include information according to the above-described embodiment #2. The UL DCI generated in S1010 may be a UL DCI indicating a beam change. If the use of the UL DCI indicating a beam change is enabled (e.g., permitted) by higher layer signaling, the first TRP may generate the UL DCI indicating a beam change.

[0162] In S1020, the first TRP may transmit UL DCI to the terminal, and the terminal may receive the UL DCI from the first TRP. In single DCI-based mTRP communication, UL DCI may be transmitted by one TRP. The terminal may check information included in the UL DCI. The terminal may update a TCI state (e.g., beam) for one of the first TRP and the second TRP based on information included in the UL DCI (e.g., TCI field, SRI, TCI update field, TCI selection field, and / or 1-bit indicator) (S1030). If the use of UL DCI indicating a beam change by upper layer signaling is enabled (e.g., permitted), the terminal may update the TCI state for one TRP based on the information included in the UL DCI. The terminal may update the TCI state for one TRP based on the method(s) according to the above-described embodiment #2. The first TRP and / or the second TRP may expect the TCI status for one TRP to be updated at the terminal. If the use of UL DCI indicating beam changes via higher-layer signaling is disabled, the terminal may update the TCI status for both the first TRP and the second TRP based on the information contained in the UL DCI.

[0163] In S1040 and S1050, the terminal may transmit the PUSCH to the first TRP and the second TRP based on the updated TCI state and the existing TCI state (i.e., the non-updated TCI state). The PUSCH transmission may be performed based on the PUSCH scheduling information included in the UL DCI. For example, if the TCI state for the first TRP is updated, the terminal may transmit the PUSCH to the first TRP based on the updated TCI state (S1040). If the TCI state for the second TRP is not updated, the terminal may transmit the PUSCH to the second TRP based on the existing TCI state (S1050). For another example, if the TCI state for the first TRP is not updated, the terminal may transmit the PUSCH to the first TRP based on the existing TCI state (S1040). If the TCI status for the second TRP is updated, the terminal can transmit a PUSCH to the second TRP based on the updated TCI status (S1050).

[0164] In S1040, if the TCI state for the first TRP is updated, the first TRP can receive the PUSCH based on the updated TCI state, and if the TCI state for the first TRP is not updated, the first TRP can receive the PUSCH based on the existing TCI state. In S1050, if the TCI state for the second TRP is updated, the second TRP can receive the PUSCH based on the updated TCI state, and if the TCI state for the second TRP is not updated, the second TRP can receive the PUSCH based on the existing TCI state.

[0165] 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.

[0166] 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.

[0167] 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.

[0168] 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.

[0169] Although the present disclosure has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present disclosure without departing from the spirit and scope of the present disclosure as set forth in the claims below.

Claims

1. As a method of UE (user equipment), A step of receiving DCI (downlink control information) including PDSCH (physical downlink shared channel) scheduling information, a TCI (transmission configuration indicator) field, and a TCI selection field from a first TRP (transmission and reception point); A step of performing an update of a TCI status for one of the first TRP and the second TRP based on the setting of the TCI field and the TCI selection field; and A step of receiving a PDSCH according to the PDSCH scheduling information from the first TRP and the second TRP based on the updated TCI state and the existing TCI state, UE's method.

2. In claim 1, The step of performing an update of the TCI status for the above one TRP is: Including the step of updating a first TCI state among the two TCI states to a TCI state indicated by the TCI field when the TCI selection field is set to a first value, and updating a second TCI state among the two TCI states to a TCI state indicated by the TCI field when the TCI selection field is set to a second value. UE's method.

3. In claim 1, Further comprising the step of receiving a message including information indicating enable or disable of use of the DCI indicating beam change prior to reception of the DCI, If the use of the DCI indicating a beam change is enabled, an update of the TCI state for the one TRP is performed based on the information included in the DCI, and if the use of the DCI indicating a beam change is disabled, an update of the TCI state for both the first TRP and the second TRP is performed based on the information included in the DCI. UE's method.

4. In claim 1, The DCI further includes a beam change indicator, and when the beam change indicator is set to a first value, an update of the TCI state for both the first TRP and the second TRP is performed, and when the beam change indicator is set to a second value, an update of the TCI state for the one TRP is performed. UE's method.

5. In claim 4, When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates one TCI state among the two TCI states, the update of the TCI state for the one TRP is performed based on the one TCI state indicated by the TCI selection field. UE's method.

6. In claim 4, When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates a first TCI state among the two TCI states, the previous TCI state corresponding to the first TCI state is updated to the first TCI state indicated by the TCI selection field. UE's method.

7. In claim 4, When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates a second TCI state among the two TCI states, the previous TCI state corresponding to the second TCI state is updated to the second TCI state indicated by the TCI selection field. UE's method.

8. In claim 4, The above DCI includes the beam change information, which is indicated to the UE by signaling. UE's method.

9. In claim 4, The existing fields included in the above DCI are reused for the beam change indicator. UE's method.

10. As a method of UE (user equipment), A step of receiving DCI (downlink control information) including PUSCH (physical uplink shared channel) scheduling information, a TCI (transmission configuration indicator) field, and an SRI (sounding reference signal resource indicator) indicating at least one TCI state from a first TRP (transmission and reception point); A step of performing an update of a TCI status for one of the first TRP and the second TRP based on the setting of the TCI field and the SRI; and A step of transmitting a PUSCH according to the PUSCH scheduling information to the first TRP and the second TRP based on the updated TCI state and the existing TCI state, UE's method.

11. In claim 10, The step of performing an update of the TCI status for the above one TRP is: Including the step of updating a first TCI state among the two TCI states to a TCI state indicated by the TCI field when the SRI is set to a first value, and updating a second TCI state among the two TCI states to a TCI state indicated by the TCI field when the SRI is set to a second value. UE's method.

12. In claim 10, Further comprising the step of receiving a message including information indicating enable or disable of use of the DCI indicating beam change prior to reception of the DCI, If the use of the DCI indicating a beam change is enabled, an update of the TCI state for the one TRP is performed based on the information included in the DCI, and if the use of the DCI indicating a beam change is disabled, an update of the TCI state for both the first TRP and the second TRP is performed based on the information included in the DCI. UE's method.

13. In claim 10, The above DCI including the TCI field is indicated to the UE by signaling, UE's method.

14. As a UE (user equipment), Contains at least one processor, At least one processor of the UE, Receive DCI (downlink control information) including PDSCH (physical downlink shared channel) scheduling information, a TCI (transmission configuration indicator) field, and a TCI selection field from a first TRP (transmission and reception point); Performing an update of a TCI status for one of the first TRP and the second TRP based on the settings of the above TCI field and the above TCI selection field; and Causing to receive a PDSCH according to the PDSCH scheduling information from the first TRP and the second TRP based on the updated TCI state and the existing TCI state. UE.

15. In claim 14, In the step of performing an update of the TCI status for the above one TRP, the at least one processor is configured to cause the UE to: When the TCI selection field is set to a first value, the first TCI state among the two TCI states is updated to the TCI state indicated by the TCI field, and when the TCI selection field is set to a second value, the second TCI state among the two TCI states is updated to the TCI state indicated by the TCI field. UE.

16. In claim 14, At least one processor of the UE, Further causing a message to be received including information indicating enable or disable use of said DCI to instruct beam change prior to reception of said DCI, If the use of the DCI indicating a beam change is enabled, an update of the TCI state for the one TRP is performed based on the information included in the DCI, and if the use of the DCI indicating a beam change is disabled, an update of the TCI state for both the first TRP and the second TRP is performed based on the information included in the DCI. UE.

17. In claim 14, The DCI further includes a beam change indicator, and when the beam change indicator is set to a first value, an update of the TCI state for both the first TRP and the second TRP is performed, and when the beam change indicator is set to a second value, an update of the TCI state for the one TRP is performed. UE.

18. In claim 17, When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates one TCI state among the two TCI states, the update of the TCI state for the one TRP is performed based on the one TCI state indicated by the TCI selection field. UE.

19. In claim 17, When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates a first TCI state among the two TCI states, the previous TCI state corresponding to the first TCI state is updated to the first TCI state indicated by the TCI selection field. UE.

20. In claim 17, When the beam change indicator is set to the second value, the TCI field indicates two TCI states, and the TCI selection field indicates a second TCI state among the two TCI states, the previous TCI state corresponding to the second TCI state is updated to the second TCI state indicated by the TCI selection field. UE.

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