Method and apparatus for indicating TCI status in communication system

Abstract

The invention discloses a method and a device for indicating a TCI state in a communication system. The method of the UE comprises the steps of: receiving DCI from at least one of a first TRP and a second TRP, the DCI including scheduling information of a PDSCH, a TCI field, and a TCI selection field; determining at least one TCI state for receiving the PDSCH based on a rule of a code point 11 of the TCI selection field and one or more TCI states indicated by the TCI field; and receiving a PDSCH from at least one of the first TRP and the second TRP based on the at least one TCI state.

Description

Technical Field

[0001] This invention relates to communication enhancement technology, and more specifically, to a technology for indicating the state of a transmission configuration indicator (TCI) in a communication system. Background Technology

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

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

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

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

[0006] In a communication network, a base station can indicate (e.g., configure) the Transmission Configuration Indicator (TCI) status for each Transmission Protocol Reference (TRP) to the terminal. In some cases, the TCI status may be ambiguous. In such situations, the terminal may not be able to accurately identify the TCI status used to receive the downlink channel, and consequently, downlink channel reception performance may degrade. Summary of the Invention

[0007] Technical issues

[0008] The present invention aims to provide a method and apparatus for indicating TCI status in a communication system.

[0009] Technical solutions

[0010] To achieve the above objectives, according to an exemplary embodiment of the present invention, a method for a user equipment (UE) is provided, comprising the following steps: receiving downlink control information (DCI) from at least one TRP of a first transmission and reception point (TRP) or a second TRP, the DCI including scheduling information of a physical downlink shared channel (PDSCH), a transmission configuration indicator (TCI) field, and a TCI selection field; determining at least one TCI state for receiving the PDSCH based on one or more TCI states indicated by the TCI field and the rule of code point 11 of the TCI selection field; and receiving the PDSCH from at least one TRP of the first TRP or the second TRP based on the at least one TCI state, wherein the TCI selection field is set to code point 00, code point 01, code point 10, or code point 11, and each of the code point 00, code point 01, code point 10, or code point 11 indicates a different TCI state application rule.

[0011] It can be that when the one or more TCI states indicated by the TCI field are {TCI state #n, none}, the UE receives a first PDSCH from the first TRP based on the TCI state #n, and the UE receives a second PDSCH from the second TRP based on the default TCI state determined by the rule of the code point 11, where n is a natural number.

[0012] The default TCI state can be a TCI state for receiving a previous PDSCH, a TCI state for receiving a previous physical downlink control channel (PDCCH), a TCI state for monitoring a control resource set (CORESET: control resource set) with the lowest control resource set identifier (CORESETidentifier (ID)), or a TCI state mapped to the lowest code point in the TCI state list.

[0013] The rule for code point 11 may be to change or maintain the TCI state used for receiving PDSCH during repeated PDSCH events.

[0014] It could be that the default TCI state is applied during the first PDSCH timing within the quasi-co-location (QCL) constraint time starting from the DCI reception time, and the TCI state applied during the second PDSCH timing after the QCL constraint time is either maintained as the default TCI state or changed to another TCI state according to the rule of the code point 11.

[0015] The UE method may further include the following steps: transmitting UE capability information to at least one of the first TRP or the second TRP, the UE capability information including information indicating whether the UE supports changing the TCI state for receiving PDSCH during repeated PDSCH timings, and when the UE supports changing the TCI state during repeated PDSCH timings, the rule of code point 11 changes the TCI state for receiving PDSCH during repeated PDSCH timings.

[0016] The rule for code point 11 may be to ignore one or more TCI states indicated by the TCI field.

[0017] It could be that, when the indication ignores the one or more TCI states indicated by the TCI field, the at least one TCI state is a TCI state for receiving a previous downlink (DL) channel, a TCI state for receiving the DCI, a TCI state for monitoring a CORESET associated with the DCI, or a TCI state for receiving random access (RA) messages during the initial access process.

[0018] It could be that the code point 11 of the TCI selection field indicates switching between multi-TRP communication and single-TRP communication, and that after receiving the PDSCH, the mTRP communication is switched to sTRP communication or the sTRP communication is switched to mTRP communication based on the code point 11.

[0019] It could be that the code point 11 of the TCI selection field indicates the priority between the beam application time and the QCL constraint time, and when the beam application time has a higher priority, the one or more TCI states indicated by the TCI field are applied after the beam application time, and when the QCL constraint time has a higher priority, the one or more TCI states indicated by the TCI field are applied after the QCL constraint time.

[0020] To achieve the above objectives, according to an exemplary embodiment of the present invention, a user equipment (UE) is provided, comprising at least one processor, the at least one processor causing the UE to perform the following operations: receiving downlink control information (DCI) from at least one TRP of a first transport receiving point (TRP) or a second TRP, the DCI including scheduling information of a physical downlink shared channel (PDSCH), a transport configuration indicator (TCI) field, and a TCI selection field; determining at least one TCI state for receiving the PDSCH based on one or more TCI states indicated by the TCI field and a rule of code point 11 of the TCI selection field; and receiving the PDSCH from at least one TRP of the first TRP or the second TRP based on the at least one TCI state, wherein the TCI selection field is set to code point 00, code point 01, code point 10, or code point 11, and each of the code point 00, the code point 01, the code point 10, or the code point 11 indicates a different TCI state application rule.

[0021] It can be that when the one or more TCI states indicated by the TCI field are {TCI state #n, none}, the UE receives a first PDSCH from the first TRP based on the TCI state #n, and the UE receives a second PDSCH from the second TRP based on the default TCI state determined by the rule of the code point 11, where n is a natural number.

[0022] The default TCI state can be the TCI state used to receive the previous PDSCH, the TCI state used to receive the previous physical downlink control channel (PDCCH), the TCI state used to monitor the control resource set (CORESET) with the lowest CORESET identifier (ID), or the TCI state in the TCI state list mapped to the lowest code point.

[0023] The rule for code point 11 may be to change or maintain the TCI state used for receiving PDSCH during repeated PDSCH events.

[0024] It could be that the default TCI state is applied during the first PDSCH timing within the quasi-co-location (QCL) constraint time starting from the DCI reception time, and the TCI state applied during the second PDSCH timing after the QCL constraint time is maintained as the default TCI state or changed to another TCI state by the rule of the code point 11.

[0025] Alternatively, the at least one processor may cause the UE to further perform the following operations: transmit UE capability information to at least one of the first TRP or the second TRP, the UE capability information including information indicating whether the UE supports changing the TCI state for receiving the PDSCH during repeated PDSCH timings, and when the UE supports changing the TCI state during repeated PDSCH timings, the rule of code point 11 changes the TCI state for receiving the PDSCH during the repeated PDSCH timings.

[0026] The rule for code point 11 may be to ignore one or more TCI states indicated by the TCI field.

[0027] It could be that, when the indication ignores the one or more TCI states indicated by the TCI field, the at least one TCI state is a TCI state for receiving a previous downlink (DL) channel, a TCI state for receiving the DCI, a TCI state for monitoring a CORESET associated with the DCI, or a TCI state for receiving random access (RA) messages during initial access.

[0028] It could be that the code point 11 of the TCI selection field indicates switching between multiple transmit receiver point (mTRP) communication and single transmit receiver point (sTRP) communication, and that after receiving the PDSCH, the mTRP communication is switched to the sTRP communication or the sTRP communication is switched to the mTRP communication based on the code point 11.

[0029] It could be that the code point 11 of the TCI selection field indicates the priority between the beam application time and the QCL constraint time, and when the beam application time has a higher priority, the one or more TCI states indicated by the TCI field are applied after the beam application time, and when the QCL constraint time has a higher priority, the one or more TCI states indicated by the TCI field are applied after the QCL constraint time.

[0030] Invention Effects

[0031] According to the present invention, the downlink control information (DCI) used for scheduling the physical downlink shared channel (PDSCH) can not only indicate the application with a unified TCI state after the beam application time (BAT), but also indicate the TCI state for the scheduled PDSCH. The base station can dynamically indicate the TCI state of the PDSCH to the terminal based on the channel conditions between the base station and the terminal and / or the usage scenario. According to the above method, the problem of ambiguous TCI state in the terminal can be solved, and the terminal can perform reception operations based on the TCI state. Attached Figure Description

[0032] Figure 1 This is a conceptual diagram illustrating an embodiment of a communication system.

[0033] Figure 2 This is a block diagram illustrating an embodiment of a communication node constituting a communication system.

[0034] Figure 3 This is a block diagram illustrating an embodiment of a communication node performing communication.

[0035] Figure 4a This is a block diagram illustrating an embodiment of the transmission path.

[0036] Figure 4b This is a block diagram illustrating an embodiment of the receiving path.

[0037] Figure 5 This is a conceptual diagram illustrating an embodiment of a system frame in a communication system.

[0038] Figure 6 This is a conceptual diagram illustrating an embodiment of a subframe in a communication system.

[0039] Figure 7 This is a conceptual diagram illustrating an embodiment of a time slot in a communication system.

[0040] Figure 8 This is a conceptual diagram illustrating an embodiment of a time-frequency resource in a communication system.

[0041] Figure 9 This is a conceptual diagram illustrating a method for indicating the unified TCI state.

[0042] Figure 10 This is a conceptual diagram illustrating an embodiment of a method for applying TCI states in PDSCH retransmission.

[0043] Figure 11a and Figure 11b This is a conceptual diagram illustrating an embodiment of a method for configuring the TCI state based on the code points of the TCI selection field. Detailed Implementation

[0044] This invention can be modified in various ways and has multiple embodiments; therefore, specific embodiments will be shown in the accompanying drawings and described in detail. However, it should be understood that this invention is not intended to be limited to the specific embodiments, and that it encompasses all modifications, equivalents, and alternatives falling within the inventive concept and scope.

[0045] Relational terms such as "first," "second," etc., may be used to describe various elements, but elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of the invention, a first component may be named a second component, and similarly, a second component may be named a first component. The term "and / or" refers to any one or a combination of the plurality of related descriptions.

[0046] In this invention, "at least one of A and B" can refer to "at least one of A or B" or "at least one of a combination of one or more A and B". Furthermore, "one or more of A and B" can refer to "one or more of A or B" or "one or more of a combination of one or more A and B".

[0047] In this invention, "(re)transmit" can mean "transmit", "retransmit", or "transmit and retransmit", "(re)configure" can mean "configure", "reconfigure", or "configure and reconfigure", "(re)connect" can mean "connect", "reconnect", or "connect and reconnect", and "(re)access" can mean "access", "reaccess", or "access and reaccess".

[0048] When a component is said to be "coupled to" or "connected to" another component, it should be understood as the component being directly "coupled" or "connected" to the other component, or it could also mean that there are other components between them. Conversely, when a component is said to be "directly coupled to" or "directly connected to" another component, it should be understood as the absence of other components between them.

[0049] The terminology used in this invention is for describing specific embodiments only and is not intended to limit the invention. Unless the context clearly specifies otherwise, singular expressions also include plural expressions. In this invention, terms such as "comprising" or "having" are intended to indicate the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification. It should be understood that these terms do not exclude the presence or addition of one or more features, numbers, steps, operations, components, parts, or combinations thereof.

[0050] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms commonly used and included in dictionaries shall be understood to have meanings appropriate to the context of this art. In this specification, unless explicitly defined, terms should not be interpreted as having ideal or overly formal meanings.

[0051] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. To facilitate a comprehensive understanding of the invention, the same reference numerals are used to refer to the same elements in the drawings, and repeated descriptions are omitted. The operations shown in the embodiments explicitly described in the invention, as well as combinations of embodiments, extensions of embodiments, and / or variations of embodiments, can be performed. Certain operations may be omitted, and the order of operations may be changed.

[0052] Even if the embodiments describe a method (e.g., signal transmission or reception) performed at a first communication node, a corresponding method (e.g., signal reception or transmission) can also be performed at a corresponding second communication node. In other words, when describing the operation of a user equipment (UE), its corresponding base station can perform an operation corresponding to that UE's operation. Conversely, when describing the operation of a base station, the corresponding UE can perform an operation corresponding to the base station's operation.

[0053] Base stations can be referred to using various terms, such as Node B (NB), Evolved Node B (eNB), Next Generation Node B (gNB), gNB, device, apparatus, node, communication node, base transceiver station (BTS), radio remote head (RRH), transmission reception point (TRP), radio unit (RU), roadside unit (RSU), transceiver, access point, access node, etc. User equipment (UE) can be referred to using various terms, such as terminal, device, apparatus, node, communication node, end node, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, on-board unit (OBU), etc.

[0054] In this invention, signaling can be one or a combination of two or more of higher-layer signaling, media access control (MAC) signaling, and physical layer (PHY) signaling. Messages used for higher-layer signaling may be referred to as "high-layer messages" or "high-layer signaling messages." Messages used for MAC signaling may be referred to as "MAC messages" or "MAC signaling messages." Messages used for PHY signaling may be referred to as "PHY messages" or "PHY signaling messages." Higher-layer signaling can refer to the operation of transmitting and receiving system information (e.g., master information block (MIB), system information block (SIB)) and / or radio resource control (RRC) messages. MAC signaling can refer to the operation of transmitting and receiving MAC control element (CE). PHY signaling can refer to the operation of transmitting and receiving control information (e.g., downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI)).

[0055] In this invention, "configuration of an operation (e.g., a transmission operation)" can refer to "configuration information required for the operation (e.g., information elements, parameters)" and / or "information instructing the execution of the operation" as signaling. "Configuration of an information element (e.g., parameters)" can refer to that information element as signaling. In this invention, "signal and / or channel" can refer to "signal," "channel," or "signal and channel," and "signal" can be used to represent "signal and / or channel."

[0056] The communication networks used in the embodiments are not limited to those described below, and the embodiments can be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, "communication network" can be used interchangeably with the term "communication system".

[0057] Figure 1 This is a conceptual diagram illustrating an embodiment of a communication system.

[0058] like Figure 1As shown, the communication system 100 may include multiple communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. Furthermore, the communication system 100 may also include a core network (e.g., a servicing gateway (S-GW), a packet data network gateway (P-GW), and a mobility management entity (MME). When the communication system 100 is a 5G communication system (e.g., an NR (new radio) system), the core network may include access and mobility management functions (AMF), user plane functions (UPF), session management functions (SMF), etc.

[0059] Multiple communication nodes 110 to 130 can support communication protocols (e.g., LTE communication protocol, LTE-A communication protocol, NR communication protocol, etc.) specified in the 3rd generation partnership project (3GPP) standard. Multiple communication nodes (110 to 130) can support Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiplexing (OFDM), Filtered Orthogonal Frequency Division Multiplexing (OFDM), Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM), Discrete Fourier Transform-Spread-OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), and Non-Orthogonal Multiple Access (NOMA). Multiple communication nodes can have the following structures: generalized frequency division multiplexing (GFDM), filter bank multi-carrier (FBMC), universal filtered multi-carrier (UFMC), and space division multiple access (SDMA).

[0060] Figure 2 This is a block diagram illustrating an embodiment of a communication node constituting a communication system.

[0061] like Figure 2As shown, the communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 connected to a network for communication. Additionally, the communication node 200 may also include an input interface device 240, an output interface device 250, a storage device 260, etc. The various components included in the communication node 200 can be connected and communicate with each other via a bus 270.

[0062] Processor 210 can execute a program stored in at least one of memory 220 and storage device 260. Processor 210 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor for performing methods according to embodiments of the present invention. Both memory 220 and storage device 260 may be constructed from at least one of volatile storage media and non-volatile storage media. For example, memory 220 may be constructed from at least one of read-only memory (ROM) and random access memory (RAM).

[0063] Refer again Figure 1 The communication system 100 may include multiple base stations 110-1, 110-2, 110-3, 120-1, 120-2 and multiple 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 can constitute a macro cell. Each of the fourth base station 120-1 and the fifth base station 120-2 can constitute a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 can 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 can 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 are all within the cell coverage area of ​​the third base station 110-3. The first terminal 130-1 is within the cell coverage area of ​​the fourth base station 120-1. The sixth terminal 130-6 is within the cell coverage area of ​​the fifth base station 120-2.

[0064] Here, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can refer to a Node B (NB), an Evolved Node B (eNB), a Next Generation Node B (gNB), an Advanced Base Station (ABS), a High Reliability Base Station (HR-BS), a Base Transceiver Station (BTS), a Radio Base Station, a Radio Transceiver, an Access Point, an Access Node, a Radio Access Station (RAS), a Mobile Multihop Relay Base Station (MMR-BS), a Relay Station (RS), an Advanced Relay Station (ARS), a High Reliability Relay Station (HR-RS), a Home Node B (HNB), and a Home Evolved Node B (HeNB). B) Roadside Unit (RSU), Remote Radio Head (RRH), Transmission Point (TP), Transmission Receiver Point (TRP), etc.

[0065] Each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can refer to User Equipment (UE), Terminal Equipment (TE), Advanced Mobile Station (AMS), High Reliability Mobile Station (HR-MS), Terminal, Access Terminal, Mobile Terminal, Station, Subscriber Station, Mobile Station, Portable Subscriber Station, Node, Equipment, On-Board Unit (OBU), etc.

[0066] Furthermore, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can operate in the same or different frequency bands. Each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be interconnected via an ideal backhaul link or a non-ideal backhaul link, and exchange information with each other through these links. Additionally, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be connected to the core network via an ideal backhaul link or a non-ideal backhaul link. Each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can transmit signals received from the core network to the corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6, and can also transmit signals received from the corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 to the core network.

[0067] In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can support multi-input multi-output (MIMO) transmission (e.g., single-user MIMO, multi-user MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, unlicensed band transmission, sidechain communication (e.g., device-to-device (D2D) communication, proximity services (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can perform operations corresponding to the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2, as well as operations supported by the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2. For example, the second base station 110-2 can transmit signals to the fourth terminal 130-4 using SU-MIMO, and the fourth terminal 130-4 can receive signals from the second base station 110-2 using SU-MIMO. Alternatively, the second base station 110-2 can transmit signals to the fourth terminal 130-4 and the fifth terminal 130-5 using MU-MIMO, and the fourth terminal 130-4 and the fifth terminal 130-5 can receive signals from the second base station 110-2 using MU-MIMO.

[0068] Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 can transmit signals to the fourth terminal 130-4 using the CoMP transmission method, and the fourth terminal 130-4 can receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 using the CoMP method. Furthermore, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can exchange signals with corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 within its cell coverage area using the CA method. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 can control the sidechain communication between the fourth terminal 130-4 and the fifth terminal 130-5. Furthermore, each of the fourth terminal 130-4 and the fifth terminal 130-5 can perform sidechain communication under the control of the second base station 110-2 and the third base station 110-3, respectively.

[0069] In addition, communication nodes that perform communication in a communication network can be configured as follows. Figure 3 The communication node shown can be Figure 2 A specific embodiment of the communication node shown.

[0070] Figure 3 This is a block diagram illustrating an embodiment of a communication node performing communication.

[0071] like Figure 3 As shown, each of the first communication node 300a and the second communication node 300b can be a base station or a UE. The first communication node 300a can transmit signals to the second communication node 300b. The transmission processor 311 included in the first communication node 300a can receive data (e.g., data unit) from the data source 310. The transmission processor 311 can receive control information from the controller 316. The control information may include at least one of system information, RRC configuration information (e.g., information configured by RRC signaling), MAC control information (e.g., MAC CE), or PHY control information (e.g., DCI, SCI).

[0072] The transmission processor 311 can generate data symbols by performing processing operations on data (e.g., encoding operations, symbol mapping operations, etc.). The transmission processor 311 can also generate control symbols by performing processing operations on control information (e.g., encoding operations, symbol mapping operations, etc.). Furthermore, the transmission processor 311 can also generate synchronization / reference symbols for synchronization signals and / or reference signals.

[0073] The Tx MIMO processor 312 can perform spatial processing operations (e.g., precoding operations) on data symbols, control symbols, and / or synchronization / reference symbols. The output of the Tx MIMO processor 312 (e.g., a symbol stream) can be provided to modulators (MODs) included in transceivers 313a to 313t. The modulator can generate modulated symbols by performing processing operations on the symbol stream, and can generate signals by performing additional processing operations (e.g., analog-to-digital conversion, amplification, filtering, up-conversion, etc.) on the modulated symbols. The signals generated by the modulators of transceivers 313a to 313t can be transmitted via antennas 314a to 314t.

[0074] Signals transmitted through the first communication node 300a can be received by antennas 364a to 364r of the second communication node 300b. The signals received by antennas 364a to 364r can be provided to demodulators (DEMODs) included in transceivers 363a to 363r. The demodulators (DEMODs) can acquire samples by performing processing operations on the signals (e.g., filtering, amplification, down-conversion, digital conversion, etc.). The demodulators (DEMODs) can perform additional processing operations on the samples to acquire symbols. MIMO detector 362 can perform MIMO detection operations on the symbols. Receiver processor 361 can perform processing operations on the symbols (e.g., deinterleaving, decoding, etc.). The output of receiver processor 361 can be provided to data sink 360 and controller 366. For example, data can be provided to data sink 360 and control information can be provided to controller 366.

[0075] On the other hand, the second communication node 300b can transmit signals to the first communication node 300a. The transmission processor 368 included in the second communication node 300b can receive data (e.g., data units) from the data source 367 and perform processing operations on the data to generate data symbols. The transmission processor 368 can receive control information from the controller 366 and perform processing operations on the control information to generate control symbols. Furthermore, the transmission processor 368 can generate reference symbols by performing processing operations on reference signals.

[0076] The Tx MIMO processor 369 can perform spatial processing operations (e.g., precoding operations) on data symbols, control symbols, and / or reference symbols. The output of the Tx MIMO processor 369 (e.g., a symbol stream) can be provided to modulators (MODs) included in transceivers 363a to 363t. The modulators (MODs) can generate modulated symbols by performing processing operations on the symbol stream, and can generate signals by performing additional processing operations (e.g., analog-to-digital conversion, amplification, filtering, up-conversion) on the modulated symbols. The signals generated by the modulators of transceivers 363a to 363t can be transmitted via antennas 364a to 364t.

[0077] Signals transmitted through the second communication node 300b can be received by antennas 314a to 314r of the first communication node 300a. The signals received by antennas 314a to 314r can be provided to demodulators (DEMODs) included in transceivers 313a to 313r. The demodulators (DEMODs) can acquire samples by performing processing operations on the signals (e.g., filtering, amplification, down-conversion, digital conversion). The demodulators (DEMODs) can perform additional processing operations on the samples to acquire symbols. The MIMO detector 320 can perform MIMO detection operations on the symbols. The receiver processor 319 can perform processing operations on the symbols (e.g., deinterleaving, decoding, etc.). The output of the receiver processor 319 can be provided to the data sink 318 and the controller 316. For example, data can be provided to the data sink 318 and control information can be provided to the controller 316.

[0078] Memory 315 and 365 can store data, control information, and / or program code. Scheduler 317 can perform scheduling operations for communication. Figure 3 The processors 311, 312, 319, 361, 368, 369 and controllers 316, 366 shown can be Figure 2 The processor 210 shown can be used to perform the methods described in this invention.

[0079] Figure 4a This is a block diagram illustrating an embodiment of the transmission path. Figure 4b This is a block diagram illustrating an embodiment of the receiving path.

[0080] like Figure 4a and Figure 4bAs shown, a transmission path 410 can be implemented in the communication node transmitting the signal, and a receiving path 420 can be implemented in the communication node receiving the signal. The transmission path 410 may include a channel coding and modulation module 411, a serial-to-parallel (S-to-P) conversion module 412, an N-point inverse fast Fourier transform (NIFFT) module 413, a parallel-to-serial (P-to-S) conversion module 414, a cyclic prefix (CP) addition module 415, and an up-converter (UC) 416. The receiving path 420 may include a down-converter (DC) 421, a CP removal module 422, an S-to-P module 423, an N-point FFT module 424, a P-to-S module 425, and a channel decoding and demodulation module 426. Here, N can be a natural number.

[0081] In transmission path 410, information bits can be input to channel coding and modulation module 411. Channel coding and modulation module 411 can perform coding operations (e.g., low-density parity check (LDPC) coding, polarization coding, etc.) and modulation operations (e.g., quadrature phase shift keying (QPSK), quadrature amplitude modulation (QAM), etc.) on the information bits. The output of channel coding and modulation module 411 can be a sequence of modulation symbols.

[0082] S-to-P module 412 can convert frequency-domain modulation symbols into parallel symbol streams, thereby generating N parallel symbol streams. N can be the number of IFFT points or FFT points. N-point IFFT module 413 can generate a time-domain signal by performing IFFT operations on the N parallel symbol streams. P-to-S module 414 can convert the output of N-point IFFT module 413 (e.g., a parallel signal) into a serial signal, thereby generating a serial signal.

[0083] The CP insertion module 415 inserts a CP signal into the signal. The UC 416 upconverts the output frequency of the CP insertion module 415 to a radio frequency (RF) frequency. Furthermore, baseband filtering can be performed on the output of the CP insertion module 415 before the upconversion operation.

[0084] The signal transmitted in transmission path 410 can be input to receiving path 420. Operations in receiving path 420 can be the inverse of operations in transmission path 410. DC 421 can down-convert the received signal frequency to the baseband frequency. CP removal module 422 can remove CP from the signal. The output of CP removal module 422 can be a serial signal. S-to-P module 423 can convert the serial signal into a parallel signal. N-point FFT module 424 can generate N parallel signals by executing an FFT algorithm. P-to-S module 425 can convert the parallel signals into a modulation symbol sequence. Channel decoding and demodulation module 426 can perform demodulation operations on the modulation symbols and recover the data by performing decoding operations on the demodulation results.

[0085] exist Figure 4a and Figure 4b In this context, the Discrete Fourier Transform (DFT) and the Inverse Discrete Fourier Transform (IDFT) can be used instead of the FFT and IFFT. Figure 4a and Figure 4b Each module (e.g., component) can be implemented through at least one of hardware, software, or firmware. For example, Figure 4a and Figure 4b Some modules can be implemented in software, while others can be implemented in hardware or a combination of hardware and software. Figure 4a and Figure 4b In this system, a module can be subdivided into multiple modules, multiple blocks can be integrated into one module, some modules can be omitted, and modules that support other functions can be added.

[0086] Figure 5 This is a conceptual diagram illustrating an embodiment of a system frame in a communication system.

[0087] like Figure 5 As shown, time resources in a communication system can be divided in units of frames. For example, system frames can be configured continuously in the time domain of the communication system. The length of a system frame is 10 milliseconds (ms). The system frame number (SFN) can be set to one of #0 to #1023. In this case, 1024 system frames can repeat in the time domain of the communication system. For example, the SFN of a system frame after system frame #1023 might be #0.

[0088] A system frame can include two half-frames. Each half-frame is 5ms long. The half-frame located at the beginning of the system frame is designated "half-frame #0," and the half-frame located at the end of the system frame is designated "half-frame #1." A system frame can include 10 subframes. Each subframe is 1ms long. The 10 subframes within a system frame are designated "subframes #0-#9."

[0089] Figure 6 This is a conceptual diagram illustrating an embodiment of a subframe in a communication system.

[0090] like Figure 6 As shown, a subframe can include n time slots, where n can be a natural number. Accordingly, a subframe can consist of one or more time slots.

[0091] Figure 7 This is a conceptual diagram illustrating an embodiment of a time slot in a communication system.

[0092] like Figure 7 As shown, a time slot can include one or more symbols. For example, Figure 7 A time slot, as shown, can include 14 symbols. The length of a time slot can vary depending on the number of symbols included and the length of the symbols. Alternatively, the length of a time slot can vary based on a set of parameters (numerology).

[0093] The parameter set applied to the physical signals and channels in a communication system is variable. The parameter set can be adjusted to meet various technical requirements of the communication system. In a communication system applying OFDM waveform technology based on cyclic prefix (CP), the parameter set may include subcarrier spacing and CP length (or CP type). Table 1 shows an embodiment of a method for configuring the parameter set of a CP-OFDM-based communication system. At least some of the parameter sets in Table 1 can be supported depending on the frequency band in which the communication system operates. Furthermore, the communication system may also support parameter sets not listed in Table 1.

[0094] [Table 1]

[0095]

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

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

[0098] Symbols can be configured as downlink (DL) symbols, flexible (FL) symbols, or uplink (UL) symbols. A time slot consisting only of DL symbols can be called a "DL time slot", a time slot consisting only of FL symbols can be called a "FL time slot", and a time slot consisting only of UL symbols can be called a "UL time slot".

[0099] The time slot format can be semi-statically configured via higher-layer signaling (e.g., RRC signaling). System information may include indications of the semi-static time slot format, and the semi-static time slot format can be configured for cell-specific use. Furthermore, the semi-static time slot format can be configured for each terminal via terminal-specific higher-layer signaling (e.g., RRC signaling). Flexible symbols in the cell-specific time slot format can be overridden as downlink or uplink symbols via terminal-specific higher-layer signaling. Additionally, the time slot format can be dynamically indicated via physical layer signaling (e.g., the slot format indicator (SFI) included in the DCI). The dynamically indicated time slot format can override the semi-statically configured time slot format. For example, the SFI can overridden the semi-statically configured flexible symbols as downlink or uplink symbols.

[0100] Reference signals may include Channel State Information-Reference Signal (CSI-RS), Sounding Reference Signal (SRS), Demodulation-Reference Signal (DM-RS), and Phase Tracking-Reference Signal (PT-RS). Channels may include Physical Broadcast Channel (PBCH), Physical Downlink Control Channel (PDCCH), Physical Downlink Shared Channel (PDSCH), Physical Uplink Control Channel (PUCCH), Physical Uplink Shared Channel (PUSCH), Physical Sidelink Control Channel (PSCCH), and Physical Sidelink Shared Channel (PSSCH). In this invention, the control channel may refer to PDCCH, PUCCH, or PSCCH, and the data channel may refer to PDSCH, PUSCH, or PSSCH.

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

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

[0103] In this invention, a resource block (RB) can refer to a common resource block (CRB). Alternatively, a resource block can refer to a physical resource block (PRB) or a virtual resource block (VRB). In a communication system, a CRB can refer to an RB that constitutes a set of consecutive RBs (e.g., a common RB grid) based on a reference frequency (e.g., point A). Carrier and / or bandwidth portions can be configured onto the common RB grid. That is, carrier and / or bandwidth portions can be constituted by CRBs. The RB or CRB constituting the bandwidth portion can be referred to as a PRB, and CRB indices can be appropriately converted to PRB indices within the bandwidth portion.

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

[0105] The terminal can perform PDCCH monitoring operations to receive PDSCH transmitted by the base station. The base station can use higher-layer messages (e.g., Radio Resource Control (RRC) messages) to inform the terminal of configuration information for PDCCH monitoring operations. The configuration information for PDCCH monitoring operations may include Control Resource Set (CORESET) information and search space information.

[0106] CORESET information may include PDCCH DMRS (demodulation reference signal) information, PDCCH precoding information, PDCCH timing information, etc. PDCCH DMRS can be the DMRS used for demodulating PDCCH. PDCCH timing refers to the region where PDCCH may exist. That is, PDCCH timing can be a region capable of transmitting DCI. PDCCH timing can also be referred to as PDCCH candidate. PDCCH timing information may include time resource information and frequency resource information used for PDCCH timing. In the time domain, the length of PDCCH timing can be indicated in symbol units. In the frequency domain, the size of PDCCH timing can be indicated in RB units (e.g., in PRB or CRB units).

[0107] Search space information may include the control resource set identifier (CORESET ID) associated with the search space, the PDCCH monitoring period, and / or the PDCCH monitoring offset. Both the PDCCH monitoring period and offset can be indicated in time slots. Additionally, the search space information may include the symbol index at which the PDCCH monitoring operation began.

[0108] The base station can configure a Bandwidth Part (BWP) for downlink communication. Each terminal's BWP configuration can be unique. The base station can use higher-layer signaling to inform the terminal of the BWP configuration information. Higher-layer signaling can refer to "system information transmission operations" and / or "RRC message transmission operations." A single terminal can have one or more BWPs configured. The terminal can receive BWP configuration information from the base station and identify the configured BWPs based on the received BWP configuration information. When multiple BWPs are configured for downlink communication, the base station can activate one or more BWPs from among them. The base station can use at least one of higher-layer signaling, a Medium Access Control (MAC) control unit (CE), or a Digital Interchange Control (DCI) to transmit the activated BWP configuration information to the terminal. The base station can use the activated BWP to perform downlink communication. The terminal can identify the activated BWP by receiving the activated BWP configuration information from the base station and perform downlink reception operations within the activated BWP.

[0109] Meanwhile, communication systems (e.g., NR communication systems, 5G communication systems, 6G communication systems) can support use cases such as enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine-type communication (mMTC). Communication systems (e.g., communication networks) can support transmit-receive point (TRP) technologies (e.g., mTRP technology and / or sTRP technology). Communication systems supporting TRP technology can be referred to as TRP systems (e.g., mTRP systems and / or sTRP systems). In this invention, "TRP" has the meaning of including "sTRP" and / or "mTRP," and "TRP" may refer to "sTRP" or "mTRP" depending on the context. TRP can refer to an antenna set, antenna group, and / or antenna array. TRP can be associated with a control resource set (CORESET) and / or a beam (e.g., a beam group).

[0110] mTRP technology can be classified as a MIMO technology. mTRP can possess characteristics of macro cells, small cells, pico cells, and / or femto cells (e.g., cell-level characteristics). mTRP can perform data transmission for a terminal. When channel (e.g., link) states are inconsistent due to obstacles and / or interference, mTRP can mitigate the effects of obstacles and / or interference. mTRP can improve the data transmission rate of terminals located at the cell edge.

[0111] Communication based on mTRPs can be performed using either Coherent Joint Transport (CJT) or Non-Coherent Joint Transport (NCJT) schemes. In the CJT scheme, the base station knows the channel information between each mTRP and the terminal, and can perform preprocessing operations on the data based on this channel information. In this case, the overhead caused by the transmission of channel information may increase, and synchronization constraints between TRPs may arise. In the NCJT scheme, the base station does not need to know the channel information between each mTRP and the terminal. The mTRPs can transmit data to the terminal without performing preprocessing operations such as phase compensation. The complexity of the NCJT scheme is likely lower than that of the CJT scheme.

[0112] NCJT-based mTRP communication can be performed using either a single-DCI or multi-DCI scheme. In a single-DCI scheme, PDSCH transmitted via an mTRP can be scheduled by a single DCI. A single DCI can be transmitted through one TRP within the mTRP. In a multi-DCI scheme, PDSCH transmitted by each TRP can be scheduled by DCIs transmitted through each of the aforementioned TRPs. 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 DCIs can be used to schedule multiple PDSCHs.

[0113] In a single-DCI scheme, a terminal can expect to receive PDSCH transmitted by different TRPs using the same time and frequency resources but through different layers. Alternatively, a terminal can expect to receive PDSCH transmitted by different TRPs using the same frequency resources and the same layer but through different time resources (e.g., different time zones). Or, a terminal can expect to receive PDSCH transmitted by different TRPs using the same time resources and the same layer but through different frequency resources (e.g., different frequency zones).

[0114] In a multi-DCI scheme, PDSCH scheduling for each TRP can be performed by an individual DCI. PDSCHs scheduled by multiple DCIs can completely or partially overlap. Alternatively, PDSCHs scheduled by multiple DCIs can not overlap. In both single-DCI and multi-DCI schemes, the DCI can include Transport Configuration Indicator (TCI) status information for PDSCHs.

[0115] The indication / configuration of a terminal's TCI state can be interpreted as the indication / configuration of a beam (e.g., transmit beam and / or receive beam). In other words, the TCI state can have a meaning corresponding to a beam. From the perspective of downlink (DL) communication, the TCI state configuration can refer to the configuration of the QCL (Quadruple Address Colocation). From the perspective of uplink (UL) communication, the TCI state configuration can refer to the configuration of the spatial filter. A unified TCI state can indicate (e.g., configure) a common beam, unaffected by DL and UL communication. Alternatively, a unified TCI state can indicate (e.g., configure) a common beam used separately for DL ​​and UL communication. A unified TCI can be referred to as "UTCI".

[0116] To enhance the reliability and / or robustness of mTRP communication, improvements such as PDCCH enhancement can be employed. PDCCH enhancement deployment scenarios can be categorized into single-frequency networks (SFN) and non-SFN networks (NSFN).

[0117] In the SFN scheme, different TRPs or different panels can use the same resources (e.g., the same time resources, the same frequency resources, and / or the same spatial resources) to transmit the same PDCCH. In other words, all TRPs or all panels can use the same DMRS configuration, the same DMRS location, and / or the same DMRS sequence to transmit PDCCH. In this case, from the perspective of the TRP or panel receiving, the TCI states may be configured to be different by default. The above embodiments can be implemented based on multiple TCI states of CORESET. There may be synchronization constraints between TRPs for ideal backhaul or near-ideal backhaul.

[0118] In the NSFN scheme, PDCCHs generated by each TRP can be multiplexed in the time and / or frequency domains, and the multiplexed PDCCHs can be transmitted to the terminal. This scheme can be a PDCCH repetition scheme based on mTRP. In the NSFN scheme, the same number of bits as the coded bits transmitted through a PDCCH generated by each TRP can be allocated according to each TRP, and the bits (e.g., coded bits) of each TRP can be transmitted through different PDCCH candidates. This scheme can correspond to a PDCCH transmission scheme based on sTRP.

[0119] In a mTRP-based PDCCH repetition scheme, the PDCCH can be replicated according to the number of TRPs, and the PDCCH can be transmitted within the same search space (e.g., search spaces with the same index) in different search space sets (each search space set has the same number of PDCCH candidates). In this case, the search space sets can exist in the same CORESET or different CORESETs. Since each CORESET may correspond to a TCI state, when transmitting PDCCH from different search spaces within the same CORESET, only one TCI state of the PDCCH transmitted in the different search spaces can be indicated (e.g., configured). In this case, the terminal can receive a PDCCH from a TRP at a specific time.

[0120] When PDCCHs are transmitted within the same search space in different CORESETs, the terminal may default to expecting to receive PDCCHs from sTRP or mTRP based on the number of TCI states (e.g., TCI states indicated or configured by the base station). In this case, a single PDCCH can be divided into multiple PDCCHs equal to the number of TRPs, and the divided PDCCHs can be transmitted in different PDCCH candidates. In this case, the aggregation level and the combined aggregation level can be the same. In the above embodiment, PDCCH candidates can be assigned to different CORESETs. The payload size of the finally assigned PDCCH combination can be the same as the payload size of the PDCCH transmitted from sTRP. Accordingly, for decoding complexity, the sTRP-based PDCCH transmission scheme may be more advantageous than the mTRP-based PDCCH repetition scheme.

[0121] In communication systems, DCI formats 1_0, 1_1, and / or 1_2 can be used for PDSCH scheduling. Different DCI formats can be used depending on the purpose. DCI format 1_0 may correspond to fallback DCI. DCI format 1_0 may be small in size and may support limited functionality. DCI format 1_0 can be used in situations where information exchange between the terminal and the base station is incomplete, such as the initial attach procedure and / or RRC reconfiguration procedure. Because it is a situation where "correct beam configuration cannot be performed between the terminal and the base station" or "correct beam configuration is not required between the terminal and the base station," DCI format 1_0 may not include fields for unified TCI state configuration.

[0122] DCI formats 1_1 and 1_2 correspond to non-backoff DCI. DCI formats 1_1 and 1_2 can be used to improve reliability. DCI formats 1_1 and 1_2 can include not only PDSCH resource configuration information but also configuration information (e.g., TCI configuration or TCI field) for terminal beams (e.g., receive beams). DCI formats 1_1 and 1_2 for scheduling PDSCH can extend a unified DCI framework for mTRP. Fields in the DCI (e.g., TCI field or TCI selection field) can be used to indicate code points mapped to a list of TCI statuses indicated (e.g., configured) via MACCE. The TCI field in the DCI is 3 bits in size. An additional field for PDSCH receive beam configuration, which is 2 bits in size, can be included in the DCI. This additional field can be referred to as the TCI selection field.

[0123] Additional fields (e.g., additional bits) are allocated for the following reasons. In sTRP communication, there may be no switching between sTRP and mTRP communication. Regarding beam selection for sTRP communication, the terminal can use a beam (e.g., an updated beam) configured based on the TCI state mapped to a code point indicated (e.g., configured) by the DCI (e.g., the TCI field included in the DCI) to transmit and receive data. The TCI state can be applied after the beam application time (BAT). BAT can refer to the beam application time. In this invention, a beam can refer to a transmit beam and / or a receive beam. In mTRP communication, switching between sTRP and mTRP communication may be necessary. The TCI state indicated (e.g., configured) by the DCI can be applied to all channels. Unlike the above scheme, a scheme for dynamically controlling the TCI state may be needed. The TCI state can be applied in a channel-specific manner. For this reason, additional fields (e.g., 2 bits) can be allocated to the DCI.

[0124] For a PDSCH (e.g., a PDSCH scheduled by the DCI) that satisfies a specific duration (e.g., a threshold) interval from the PDCCH (e.g., the PDCCH resource receiving the aforementioned DCI), the terminal can expect to configure the receive beam of the PDSCH using the TCI state indicated by the DCI. This specific duration (e.g., the threshold) can be timeDurationForQCL. If the PDSCH does not satisfy the specific duration (e.g., the threshold), or if the PDSCH satisfies the specific duration (e.g., the threshold) but no TCI state is indicated (e.g., configured), the terminal can configure the receive beam of the PDSCH to be the same as the receive beam of the PDCCH, and can expect to use the configured receive beam to receive the PDSCH. "PDSCH satisfies a specific duration" can refer to "the case where the PDSCH is received after the specific duration." "PDSCH does not satisfy a specific duration" can refer to "the case where the PDSCH is received within the specific duration."

[0125] In situations where the duration of beam configuration cannot be guaranteed (e.g., a specific duration has not yet ended) or where the TCI state is not indicated (e.g., configured), the terminal can expect to use the default beam to receive the PDSCH. The default beam can be the receive beam of the PDCCH. In extensions to the unified TCI state framework for mTRP communication, it may be necessary for the base station and / or the terminal to operate based on a specific duration (e.g., a threshold).

[0126] Regarding the extension of the unified TCI state framework for mTRP communication, DCI may include 3 bits for configuring the TCI state of sTRP communication, plus additional bits (e.g., 2 bits). These additional bits may be bits used for mTRP communication.

[0127] Figure 9 This is a conceptual diagram illustrating a method for indicating the unified TCI state.

[0128] like Figure 9 As shown, the terminal can communicate with two TRPs (e.g., TRP#1 and TRP#2). Before the DCI indicates the TCI state, the terminal can receive the DL channels of TRP#1 and TRP#2 based on the DL state or a combination of TCI states. The terminal can receive the DL channel of TRP#1 using a receive beam configuration based on TCI#3 or TCI state. The terminal can receive the DL channel of TRP#2 using a receive beam configuration based on TCI#7 or TCI state. Thereafter, the base station can transmit a DCI including a field (e.g., a TCI field) indicating the code point corresponding to {TCI #1, None}. This DCI can be transmitted to the terminal via at least one of the TRPs, TRP#1 or TRP#2, connected to the base station. The terminal can receive the DCI from the base station and identify the information (e.g., fields) included in the DCI. The terminal can identify a field whose code point corresponds to {TCI #1, None} indicated by the DCI.

[0129] In this scenario, the terminal may not expect to receive PDSCH from TRP#2. In other words, with the DCI indicating {TCI#1, None}, the TCI state of TRP#2 may be ambiguous, and the terminal may not expect to receive PDSCH from TRP#2. Alternatively, the terminal may expect to receive PDSCH from TRP#2 using TCI#7, previously used for PDSCH reception. To resolve this ambiguity, the DCI may include additional fields (e.g., a TCI selection field). The TCI selection field is 2 bits in size. A TCI selection field can be introduced to switch between mTRP and sTRP communication.

[0130] The 2-bit TCI selection field can indicate four code points (00, 01, 10, 11). Among these four code points, the definitions of three code points are shown in Table 2 below.

[0131] [Table 2]

[0132]

[0133] It may be necessary to define the remaining code points (e.g., 11) of the TCI selection field, and it may be necessary to define the operation of the terminal and / or base station based on the remaining code points (e.g., 11) of the TCI selection field. Embodiments of the present invention are applicable not only to DCI formats 1_1 and 1_2, but also to all DCI formats. For example, embodiments of the present invention can be applied to all DCI formats that can be used for TCI state configuration.

[0134] [Method #1: Code point 11 of the TCI selection field indicates the default beam when the TCI status is "None"]

[0135] exist Figure 9 In some embodiments, code point 10 of the TCI selection field may not support a TCI state that does not indicate TRP #2, such as {TCI #1, None}. When the TCI field indicates (e.g., is configured) a list of TCI states with the TCI state set to "None", it may be necessary to define the terminal operation for the TRP corresponding to the TCI state configured as "None". In other words, to perform a receive operation corresponding to a TRP with the TCI state set to "None", it may be necessary to define the beam used by the terminal (e.g., which TCI state). This beam may be the CORESET beam associated with a previous PDCCH reception, or the beam used for PDSCH reception during the initial access phase.

[0136] When the default beam configuration is not applied, code point 11 of the TCI selection field can indicate the TCI state configuration. For example, the base station can use a TCI field included in the DCI (e.g., a 3-bit TCI field) to indicate (e.g., configure) {TCI #1, None} for {TRP#1, TRP#2} to the terminal. In this scenario, when the TCI selection field included in the DCI indicates code point 10, the terminal can expect to receive PDSCH#1 from TRP#1 using TCI#1, and the terminal can expect to receive PDSCH#2 from TRP#2 using the CORESET beam (e.g., the receive beam) associated with the previous DCI (e.g., the previous PDCCH). This operation can be performed when the TCI state is indicated as "None" (e.g., "None" state) and the terminal's beam configuration is consistent with the CORESET beam (e.g., the receive beam). PDSCH#1 and PDSCH#2 can be the same PDSCH or different PDSCHs.

[0137] For example, a base station can use the TCI field included in the DCI (e.g., a 3-bit TCI field) to indicate (e.g., configure) to the terminal {TCI #1, None} for {TRP#1, TRP#2}. In this scenario, when the TCI selection field included in the DCI indicates code point 11, the terminal can expect to receive PDSCH#1 from TRP#1 using TCI#1 (e.g., unified TCI#1), and the terminal can expect to receive PDSCH#2 from TRP#2 using a candidate default beam (e.g., default beam or default TCI state). The candidate default beam (e.g., default beam, default TCI) can be the receive beam of the PDSCH during the initial access process or the receive beam of a previous PDSCH. In other words, the candidate default beam (e.g., default beam, default receive beam, default TCI state) can be the receive beam used to receive RA messages (e.g., msg2, msg4, msgB) during the initial access process. The receive beam can have a meaning corresponding to the TCI state. The default beam can refer to the default TCI state.

[0138] The TCI state order and / or mapping of code point 11 in the TCI selection field can be the same as the TCI state order and / or mapping of other code points in the TCI selection field (e.g., code point 00, code point 01, and / or code point 10). Code point 11 in the TCI selection field can indicate that, when the TCI state is indicated as "none" (e.g., "no" state), the terminal applies a different TCI state than a predefined method (e.g., a conventional method) (e.g., a receive beam with a different TCI state).

[0139] For example, the TCI field included in the DCI can indicate {None, TCI#3} for {TRP#1, TRP#2} (e.g., code point #7 mapped to {None, TCI#3} in the TCI state list for {TRP#1, TRP#2} (e.g., code point 110)), and the TCI selection field included in the aforementioned DCI can indicate code point 00. In this scenario, the receive beams of the PDSCH transmitted by both TRPs can both follow the "None" state. The terminal can configure (e.g., determine, select) the receive beams in the "None" state based on predefined rules (e.g., configuration). For example, a terminal may select the receive beam in the "None" state from the following: (1) the beam used to receive the PDSCH (e.g., previous PDSCH) for each TRP (e.g., receive beam, TCI state); (2) the beam used to receive the PDCCH (e.g., previous PDCCH) for each TRP (e.g., receive beam, TCI state); (3) the receive beam used to monitor the CORESET with the lowest control resource set identifier (CORESET ID) (e.g., TCI state); or (4) the TCI state mapped to the lowest code point in the TCI state list (e.g., receive beam of TCI state). The method of selecting the receive beam based on (1), (2), (3), or (4) above can be a basic method (e.g., configuration method) for the terminal to select the receive beam.

[0140] When the TCI selection field is configured as code point 11, the terminal can select (e.g., configure) the receive beam in the "none" state (e.g., "none" value, "none") based on different rules. When the TCI selection field is configured as code point 00, 01, or 10, and the TCI state is in the "none" state (e.g., "none" value, "none"), the terminal can select (e.g., configure) the receive beam based on one of the methods in (1) to (4). When the TCI selection field is configured as code point 11, and the TCI state is in the "none" state (e.g., "none" value, "none"), the terminal can select (e.g., configure) the receive beam according to the remaining methods other than those selected in (1) to (4).

[0141] [Method #2: Code point 11 of the TCI selection field can be used as a dynamic switch (on / off) indicator for repeating PDSCH]

[0142] In the NCJT scheme, PDSCH scheduling for mTRPs can be performed through a single DCI. In this case, to improve the reliability of PDSCH transmission and / or avoid interference, PDSCH retransmission can be supported. Each TRP can retransmit PDSCH in different resources. These different resources can be different resources in the time domain (e.g., time resources according to tdmSchemeA or inter-slot TDM) and / or different resources in the frequency domain (e.g., frequency resources according to fdmSchemeA or fdmSchemeB).

[0143] Code point 11 in the TCI selection field can be used as an indicator to indicate whether the PDSCH receive beam (e.g., TCI state) is maintained or changed during repeated PDSCH events (e.g., repeated PDSCH resources). A QCL constraint time (e.g., threshold, timeDurationForQCL) for applying QCL can be defined between the PDCCH and PDSCH. Based on the QCL constraint time, "whether to apply the TCI state indicated by the DCI" and / or "the configuration method of the terminal's default receive beam" may vary. The default receive beam can be applied to the reception of PDSCH received within the QCL constraint time starting from the reception of the PDCCH. The default receive beam can refer to the default TCI state. The default receive beam may not be applied to the reception of PDSCH after the QCL constraint time starting from the reception of the PDCCH. The QCL constraint time may include the time required to process delays and beam scanning (e.g., beam switching, beam changes) during PDCCH reception. The QCL constraint time can be determined based on terminal capabilities. The base station can inform the terminal of the QCL constraint time information via signaling. The signaling may include at least one of SI signaling, RRC signaling, MAC signaling, or PHY signaling.

[0144] Figure 10 This is a conceptual diagram illustrating an embodiment of a method for applying TCI states in PDSCH retransmission.

[0145] like Figure 10As shown, PDSCH opportunities can be multiplexed in the time domain. TRP#1 can repeatedly transmit PDSCH within a PDSCH opportunity (e.g., PDSCH #1). When all PDSCH opportunities exist within the QCL constraint time starting from the DCI (e.g., PDCCH) reception time, the terminal can expect to receive PDSCH using the default receive beam (e.g., default TCI) in all PDSCH opportunities. When "PDSCH retransmission is scheduled by the DCI, some PDSCH opportunities exist within the QCL constraint time starting from the DCI reception time, while the remaining PDSCH opportunities exist after the QCL constraint time starting from the DCI reception time," the terminal can expect to receive PDSCH using the default receive beam (e.g., default TCI) in some PDSCH opportunities existing within the QCL constraint time, and the terminal can expect to receive PDSCH using a receive beam according to predefined rules (e.g., the default receive beam or a receive beam according to the TCI state indicated by the DCI) in some PDSCH opportunities existing after the QCL constraint time. In other words, the TCI state indicated by the DCI can be applied to PDSCH reception during a PDSCH timing that exists after the QCL constraint time starting from the DCI reception time.

[0146] The base station can expect to use the default receive beam (e.g., default TCI) to transmit PDSCH within the QCL constraint time. Among the multiple PDSCH opportunities, some may exist after the QCL constraint time. In some PDSCH opportunities existing after the QCL constraint time, the terminal can expect to receive PDSCH using the default receive beam (rather than using the TCI state indicated by the DCI). Alternatively, in some PDSCH opportunities existing after the QCL constraint time, the terminal can expect to receive PDSCH using the TCI state indicated by the DCI.

[0147] The above operations may lead to performance degradation, which can be avoided by using the TCI selection field included in the DCI. Code point 11 of the TCI selection field indicates whether beam scanning (or beam switching, beam change, TCI modification) based on QCL constraint time (e.g., threshold, timeDurationForQCL) is allowed. When the TCI selection field is configured to code point 00, 01, or 10, the terminal can expect to receive the PDSCH using a fixed receive beam (e.g., fixed TCI state), unaffected by the QCL constraint time. When the TCI selection field is configured to code point 11, the terminal can expect to receive the PDSCH using either the "receive beam based on the TCI state indicated by the DCI after the QCL constraint time from the DCI reception time" or the default receive beam. The base station can expect to transmit the PDSCH using either the "transmit beam based on the TCI state indicated by the DCI after the QCL constraint time from the DCI transmission time" or the default transmission beam.

[0148] The application of the TCI state of each TRP to the PDSCH can be based on the rules of the code point "00", "01", "10", or "11" in the TCI selection field. The code point "11" in the TCI selection field can follow the rules of one of the TCI selection field code points "00", "01", or "10". For example, the code point "11" in the TCI selection field can follow the rules of the TCI selection field code point "00". In this case, the terminal can receive the PDSCH from both TRPs based on the first of the two indicated TCI states. The terminal can receive the PDSCH within the QCL constraint time using either the default receive beam or the receive beam according to the TCI state (e.g., the TCI state indicated by the DCI), and the terminal can receive the PDSCH after the QCL constraint time using the receive beam according to the TCI state indicated by the DCI (or the default receive beam).

[0149] The code point "11" in the TCI selection field can follow the rule of one of the code points "00", "01", or "10" in the TCI selection field, and the code point "11" in the TCI selection field can mean that beam scanning is allowed after the QCL constraint time (e.g., beam switching, beam change, TCI change). Alternatively, the code points "00", "01", and / or "10" in the TCI selection field mean that beam scanning is allowed after the QCL constraint time, and the code point "11" in the TCI selection field means that beam scanning is prohibited after the QCL constraint time.

[0150] The terminal can generate a UE capability report, which includes information indicating whether beam scanning (e.g., TCI state change) is supported during PDSCH retransmissions (e.g., retransmission PDSCH timing), and the terminal can transmit the UE capability report to the base station. The UE capability report can be transmitted to the base station via TRP. The base station can receive the UE capability report from the terminal and identify the information included in the UE capability report (e.g., information elements). Based on whether the terminal supports beam scanning during PDSCH retransmissions, the base station can use code point 11 of the TCI selection field to allow or prohibit beam scanning after the QCL constraint time. When the terminal supports beam scanning during PDSCH retransmissions, the rule of code point 11 of the TCI selection field transmitted by the base station can be to allow beam scanning after the QCL constraint time. When the terminal does not support beam scanning during PDSCH retransmissions, the rule of code point 11 of the TCI selection field transmitted by the base station can be to prohibit beam scanning after the QCL constraint time.

[0151] The above embodiments can be similarly applied to BAT (beamAppTime). The terminal can apply the TCI state indicated by DCI after BAT. The DL channel (e.g., PDSCH) may exist within BAT, while the UL channel (e.g., PUSCH) may exist after BAT. Alternatively, the UL channel (e.g., PUSCH) may exist within BAT, while the DL channel (e.g., PDSCH) may exist after BAT. In this case, code point 11 of the TCI selection field can indicate whether beam scanning (e.g., beam switching, beam change, TCI state) is allowed after BAT.

[0152] [Method #3: Code point 11 of the TCI selection field can be used as an indicator of whether the TCI status indicated by the DCI (e.g., the DCI used for PDSCH scheduling) is ignored (e.g., configuration)]

[0153] In method #1 and / or method #2, the receive beam of the PDSCH can be configured based on the TCI state indicated by the DCI that schedules the PDSCH. The DCI may include PDSCH scheduling information, a TCI field, and / or a TCI selection field. Additionally, the DCI may include other fields (e.g., other information elements). The base station and / or terminal can anticipate applying the TCI state indicated by the DCI after the time required for beam alignment (e.g., BAT). The TCI selection field (e.g., a 2-bit TCI selection field) can be used for dynamic beam configuration of the PDSCH present within the BAT.

[0154] Since the TCI field is 3 bits in size, using a 2-bit TCI selection field to configure the PDSCH receive beam may affect the PDSCH's receive performance. Terminal overhead may increase when using a 2-bit TCI selection field to configure the PDSCH receive beam.

[0155] The receive beam of the PDSCH can be configured to be the receive beam of the previous PDSCH or the previous DL channel, instead of being configured to be the TCI selection field included in the DCI of the scheduled PDSCH described above. Code point 11 of the TCI selection field can indicate: "Configure the receive beam of the PDSCH to be the receive beam of the previous PDSCH or the previous DL channel, instead of being configured to be the TCI selection field included in the DCI of the scheduled PDSCH described above."

[0156] A DCI may include a TCI field and a TCI selection field, and the code points “00”, “01”, and / or “10” of the TCI selection field may be associated with the TCI state (e.g., the application rules of the TCI state) as described above. The code point “11” of the TCI selection field may indicate that the TCI field is ignored (e.g., a TCI field included in the same DCI as the TCI selection field).

[0157] Figure 11a and Figure 11b This is a conceptual diagram illustrating an embodiment of a method for configuring TCI states based on TCI selection field code points.

[0158] like Figure 11a and Figure 11b As shown, the base station can transmit a DCI including a TCI field and a TCI selection field. This DCI may further include PDSCH scheduling information. The base station's DCI can be transmitted to the terminal via TRP#1 and / or TRP#2. The TCI field can indicate (e.g., configure) {TCI state #1, TCI state #3} to the terminal. Figure 11a In this embodiment, the code point of the TCI selection field can be "00". Figure 11b In one embodiment, the code point of the TCI selection field can be "11".

[0159] exist Figure 11a In this embodiment, since the TCI selection field is set to code point "00", the terminal can receive the PDSCH of all TRPs (e.g., TRP#1 and TRP#2) based on the first TCI state (e.g., TCI state #1) in {TCI state #1, TCI state #3} indicated by the TCI field. Figure 11bIn this embodiment, since the TCI selection field is set to code point "11", the terminal can ignore {TCI state #1, TCI state #3} indicated by the TCI field, and the terminal can expect to receive the PDSCH based on the TCI state used to receive the previous PDSCH and / or the previous DL channel. For example, the terminal can receive PDSCH #1 of TRP #1 based on TCI state #3, and receive PDSCH #2 of TRP #2 based on TCI state #7.

[0160] exist Figure 11b In this embodiment, the terminal may use a beam configuration for receiving the DL channel of each TRP before receiving the DCI (e.g., PDCCH), a beam configuration for receiving the DCI, or a beam configuration for monitoring the CORESET associated with the DCI to receive the PDSCH scheduled by the DCI. The receive beam used to receive the PDSCH may be the receive beam used to receive msg2, msg4, or msgB during the initial access procedure (e.g., random access (RA) procedure).

[0161] When the DCI includes a TCI field and a TCI selection field, and the TCI selection field is configured as code point 11, the terminal can ignore the TCI field included in the DCI. In other words, regardless of how the TCI field is configured, the terminal can use the receive beam (e.g., TCI state) for receiving previous DL channels, the receive beam (e.g., TCI state) for receiving the DCI, the receive beam (e.g., TCI state) for monitoring the CORESET associated with the DCI, or the receive beam (e.g., TCI state) for receiving messages (e.g., msg2, msg4, msgB) during the initial access process to receive the PDSCH.

[0162] [Method #4: The code point "11" in the TCI selection field can be used as an indicator to switch between mTRP and sTRP communication]

[0163] DCI may include PDSCH scheduling information, a TCI field, and / or a TCI selection field. The code point "11" in the TCI selection field indicates that, after a PDSCH transmission scheduled by DCI, the communication switches from mTRP to sTRP or from sTRP to mTRP for other DL communications and / or other UL communications.

[0164] The list of TCI states mapped to code points in the TCI field indicates a single TCI state. In this case, based on code point "11" in the TCI selection field, transmission and reception operations for a TRP associated with an unconfigured TCI state may not be expected. Alternatively, based on code point "11" in the TCI selection field, transmission and reception operations for a TRP associated with a configured TCI state may be expected. The terminal can receive the PDSCH based on the TCI state according to the rules of code points "00", "01", or "10" in the TCI selection field included in the DCI. Upon receiving the PDSCH scheduled by the DCI, the terminal can expect a switch from mTRP communication to sTRP communication or a switch from sTRP communication to mTRP communication.

[0165] The switching condition can be the difference between the active TCI state list and the current TCI state list indicated by the DCI. In the case of "assuming a unified TCI state configured as a union type, the TCI field is configured as 011, the TCI state list indicated by the DCI scheduling PDSCH is {TCI #1, None}, and the active TCI state list before the DCI is {TCI#3, TCI#4}", the terminal can expect to receive multiple PDSCHs and expect to switch from mTRP communication to sTRP communication after receiving multiple PDSCHs. Conversely, in the above embodiment, the terminal can expect to switch from sTRP communication to mTRP communication.

[0166] [Method #5: The code point "11" in the TCI selection field can indicate the priority between BAT and QCL constraint time (timeDurationForQCL), or the code point "11" in the TCI selection field can indicate whether to follow BAT or QCL constraint time.]

[0167] The relationship between BAT and QCL constraint time (timeDurationForQCL) can be as follows: BAT can be a value applicable not only to PDSCH but also to other physical channels. TimeDurationForQCL can be a constraint time specific to PDSCH. Whether the receive beam (e.g., beam configuration, TCI state) associated with the TCI selection field of the PDSCH is applied depends on timeDurationForQCL. PDSCH scheduled by DCI can be allocated before or after BAT. When the priority of QCL constraint time is higher than that of BAT, QCL constraint time can be applied. In this case, the TCI state indicated by the TCI field can be applied after QCL constraint time. When the priority of BAT is higher than that of QCL constraint time, BAT can be applied. In this case, the TCI state indicated by the TCI field can be applied after BAT.

[0168] When the code point "00", "01", or "10" of the TCI selection field satisfies timeDurationForQCL (regardless of the BAT setting), the TCI state configured (e.g., indicated) by the DCI can be assumed to be applied. The code point "11" of the TCI selection field can indicate that, if both BAT and timeDurationForQCL are satisfied, the TCI state configured (e.g., indicated) by the DCI is applied. The relationship between the TCI states of multiple PDSCHs scheduled by the DCI can follow the rules of the code points "00", "01", or "10" of the TCI selection field. "Satisfying timeDurationForQCL" may mean "timeDurationForQCL has ended". "The code point of the TCI selection field satisfies timeDurationForQCL" may mean "the code point of this TCI selection field is applied after timeDurationForQCL has ended". "Satisfying BAT" may mean "BAT has ended". "The code point of the TCI selection field satisfies BAT" may mean "the code point of the TCI selection field is applied after BAT has ended".

[0169] PDSCH can be configured when the code point "00", "01", or "10" of the TCI selection field satisfies the minimum value of BAT and timeDurationForQCL. When the application of TCI status configuration configured (e.g., indicated) by DCI for PDSCH is allowed, the code point "11" of the TCI selection field can indicate: "Apply TCI status for PDSCH resources that exist after the PDCCH based on the larger value of BAT and timeDurationForQCL (e.g., after the resource indicated by the PDCCH)."

[0170] Embodiments of the present invention can be applied to PDCCHs (e.g., DCI) that include PUSCH scheduling information. In other words, embodiments of the present invention can be applied to the application of fields in the DCI format that include PUSCH scheduling information, and / or the configuration of PUSCH transmission beams (e.g., spatial filters, TCI states). In embodiments of the present invention, DCI can be interpreted as UCI.

[0171] Embodiments of the present invention can be applied based on the interval between the PDCCH that schedules the PDSCH and the PDSCH scheduled by the PDCCH. In embodiments of the present invention, the function can be applied to the beam application time (e.g., BAT) required for beam alignment between the base station and the terminal.

[0172] Embodiments of the present invention can be performed based on the TCI selection field and / or other fields in the DCI. Embodiments of the present invention can be implemented using signaling other than the DCI (e.g., SI signaling, RRC signaling, MAC signaling). Embodiments of the present invention can be applied to communications using N TRPs and / or N panels. N can be a natural number equal to or greater than 2.

[0173] The operation of the method according to the invention can be implemented as a computer-readable program or code in a computer-readable recording medium. The computer-readable recording medium may include various recording means for storing data readable by a computer system. Furthermore, the computer-readable recording medium may store and execute programs or code distributed across computer systems connected via a network, and readable by computers in a distributed manner.

[0174] Computer-readable recording media may include hardware devices specifically configured for storing and executing program commands, such as ROM, RAM, or flash memory. Program commands may include not only machine language code generated by a compiler, but also high-level language code executed by a computer through an interpreter.

[0175] Although certain aspects of the invention have been described in the context of an apparatus, these may also represent a description of a corresponding method, wherein a module or apparatus may correspond to a step or feature of a method step. Similarly, aspects described in the context of a method may be expressed as features of a corresponding module or item or a corresponding apparatus. Some or all of the steps of a method may be performed by (or by using) hardware devices such as microprocessors, programmable computers, or electronic circuits. In some embodiments, one or more key steps of the method may be performed by such devices.

[0176] In some embodiments, programmable logic devices such as field-programmable gate arrays (FPGAs) may be used to perform some or all of the functions of the methods described herein. In some embodiments, the FPGA may work in conjunction with a microprocessor to perform one of the methods described herein. Generally, these methods are preferably performed by specific hardware devices.

[0177] The present invention has been described above with reference to preferred embodiments, but those skilled in the art should understand that various modifications and alterations can be made to the form and scope of the present invention without departing from the technical concept and scope defined by the appended claims.

Claims

1. A method for a user equipment (UE), in, Includes the following steps: Downlink control information (DCI) is received from at least one of the first transmission receiving point (TRP) or the second TRP, the DCI including scheduling information for the physical downlink shared channel (PDSCH), a transmission configuration indicator (TCI) field, and a TCI selection field; Based on the rules of one or more TCI states indicated by the TCI field and code point 11 of the TCI selection field, at least one TCI state for receiving the PDSCH is determined; and Based on the at least one TCI state, the PDSCH is received from at least one of the first TRP or the second TRP. The TCI selection field is set to code point 00, code point 01, code point 10 or code point 11, and each of the code points 00, 01, 10 or 11 indicates a different TCI state application rule.

2. The method for the UE according to claim 1, wherein, When the one or more TCI states indicated by the TCI field are {TCI state #n, none}, the UE receives a first PDSCH from the first TRP based on the TCI state #n, and the UE receives a second PDSCH from the second TRP based on the default TCI state determined by the rule of the code point 11. n is a natural number.

3. The method for the UE according to claim 2, wherein, The default TCI state is the TCI state used to receive the previous PDSCH, the TCI state used to receive the previous Physical Downlink Control Channel (PDCCH), the TCI state used to monitor the Control Resource Set (CORESET) with the lowest Control Resource Set Identifier (CORESET ID), or the TCI state mapped to the lowest code point in the TCI state list.

4. The method for the UE according to claim 1, wherein, The rule for code point 11 is to change or maintain the TCI state used to receive the PDSCH during repeated PDSCH events.

5. The method for the UE according to claim 4, wherein, The default TCI state is applied during the first PDSCH timing within the quasi-co-location (QCL) constraint time starting from the DCI reception time, and the TCI state applied during the second PDSCH timing after the QCL constraint time is either maintained as the default TCI state or changed to another TCI state according to the rules of the code point 11.

6. The method for the UE according to claim 4, wherein, It also includes the following steps: UE capability information is transmitted to at least one of the first TRP or the second TRP. The UE capability information includes information indicating whether the UE supports changing the TCI state for receiving the PDSCH during repeated PDSCH events. Furthermore, when the UE supports changing the TCI state during the repeated PDSCH timing, the rule of code point 11 changes the TCI state used for receiving the PDSCH during the repeated PDSCH timing.

7. The method for the UE according to claim 1, wherein, The rule for code point 11 is to ignore the one or more TCI states indicated by the TCI field.

8. The method for the UE according to claim 7, wherein, When the indication ignores the one or more TCI states indicated by the TCI field, the at least one TCI state is a TCI state for receiving a previous downlink (DL) channel, a TCI state for receiving the DCI, a TCI state for monitoring a CORESET associated with the DCI, or a TCI state for receiving random access (RA) messages during initial access.

9. The method for the UE according to claim 1, wherein, The code point 11 of the TCI selection field indicates switching between multiple transmit receiver point (mTRP) communication and single transmit receiver point (sTRP) communication, and after receiving the PDSCH, the mTRP communication is switched to the sTRP communication or the sTRP communication is switched to the mTRP communication based on the code point 11.

10. The method for the UE according to claim 1, wherein, The code point 11 of the TCI selection field indicates the priority between beam application time and QCL constraint time, and, When the beam application time has a higher priority, the one or more TCI states indicated by the TCI field are applied after the beam application time. When the QCL constraint time has a higher priority, the one or more TCI states indicated by the TCI field are applied after the QCL constraint time.

11. A user equipment (UE), wherein, The user equipment includes at least one processor. The at least one processor causes the UE to perform the following operations: Downlink control information (DCI) is received from at least one of the first transmission receiving point (TRP) or the second TRP, the DCI including scheduling information for the physical downlink shared channel (PDSCH), a transmission configuration indicator (TCI) field, and a TCI selection field; Based on the rules of one or more TCI states indicated by the TCI field and code point 11 of the TCI selection field, at least one TCI state for receiving the PDSCH is determined. as well as Based on the at least one TCI state, the PDSCH is received from at least one of the first TRP or the second TRP. The TCI selection field is set to code point 00, code point 01, code point 10 or code point 11, and each of the code points 00, 01, 10 or 11 indicates a different TCI state application rule.

12. The UE according to claim 11, wherein, When the one or more TCI states indicated by the TCI field are {TCI state #n, none}, the UE receives a first PDSCH from the first TRP based on the TCI state #n, and the UE receives a second PDSCH from the second TRP based on the default TCI state determined by the rule of the code point 11. n is a natural number.

13. The UE according to claim 12, wherein, The default TCI state is the TCI state used to receive the previous PDSCH, the TCI state used to receive the previous Physical Downlink Control Channel (PDCCH), the TCI state used to monitor the Control Resource Set (CORESET) with the lowest Control Resource Set Identifier (CORESET ID), or the TCI state mapped to the lowest code point in the TCI state list.

14. The UE according to claim 11, wherein, The rule for code point 11 is to change or maintain the TCI state used to receive the PDSCH during repeated PDSCH events.

15. The UE according to claim 14, wherein, The default TCI state is applied during the first PDSCH timing within the quasi-co-location (QCL) constraint time starting from the DCI reception time, and the TCI state applied during the second PDSCH timing after the QCL constraint time is either maintained as the default TCI state or changed to another TCI state according to the rules of the code point 11.

16. The UE according to claim 14, wherein, The at least one processor causes the UE to further perform the following operations: transmit UE capability information to at least one of the first TRP or the second TRP, the UE capability information including information indicating whether the UE supports changing the TCI state for receiving the PDSCH during repeated PDSCH timings. Furthermore, when the UE supports changing the TCI state during the repeated PDSCH timing, the rule of code point 11 changes the TCI state used for receiving the PDSCH during the repeated PDSCH timing.

17. The UE according to claim 11, wherein, The rule for code point 11 is to ignore the one or more TCI states indicated by the TCI field.

18. The UE according to claim 17, wherein, When the indication ignores the one or more TCI states indicated by the TCI field, the at least one TCI state is a TCI state for receiving a previous downlink (DL) channel, a TCI state for receiving the DCI, a TCI state for monitoring a CORESET associated with the DCI, or a TCI state for receiving random access (RA) messages during initial access.

19. The UE according to claim 11, wherein, The code point 11 of the TCI selection field indicates switching between multiple transmit receiver point (mTRP) communication and single transmit receiver point (sTRP) communication, and after receiving the PDSCH, the mTRP communication is switched to the sTRP communication or the sTRP communication is switched to the mTRP communication based on the code point 11.

20. The UE according to claim 11, wherein, The code point 11 of the TCI selection field indicates the priority between beam application time and QCL constraint time, and, When the beam application time has a higher priority, the one or more TCI states indicated by the TCI field are applied after the beam application time. When the QCL constraint time has a higher priority, the one or more TCI states indicated by the TCI field are applied after the QCL constraint time.

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