TRP switching application method and device

Abstract

Methods and apparatus for application TRP handover are disclosed. The method of the UE comprises the steps of: performing a first TRP communication with a base station; receiving a first indication of a TRP handover operation from the base station; determining the application time of the TRP switching operation based on the first indication; performing a TRP switching operation from the first TRP communication to the second TRP communication at the application time; and performing the second TRP communication with the base station.

Description

Technical Field

[0001] This disclosure relates to enhanced communication technologies, and more specifically, to technologies for applying transmit-receive point (TRP) switching in a communication system. Background Technology

[0002] Communication networks (e.g., 5G or 6G) are being developed to provide enhanced communication services compared to existing networks (e.g., Long Term Evolution (LTE), LEA-Advanced (LTE-A), etc.). 5G networks (e.g., New Radio (NR) networks) can support both sub-6 GHz and above 6 GHz frequency bands. In other words, 5G networks can support Frequency Area 1 (FR1) and / or FR2 bands. Compared to LTE networks, 5G networks can support a wider range of communication services and scenarios. For example, use cases for 5G networks can include enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), massive machine-type communication (mMTC), etc.

[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 ultra-high performance, ultra-wide bandwidth, ultra-spatial capabilities, ultra-high precision, ultra-intelligent operation, and / or ultra-high reliability. 6G communication networks can support diverse wideband frequencies and can be applied to various use cases, such as terrestrial communication, non-terrestrial communication, and sidelink communication.

[0004] On the other hand, multiple transmit / receive points (mTRPs) can be introduced in communication networks (e.g., 5G and / or 6G networks). mTRPs can be geographically separated. Base stations can use mTRPs to communicate with terminals. mTRP technology can be used to address quality of service (QoS) degradation issues at cell edge terminals and / or inter-cell interference problems. 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 a Coherent Joint Transport (CJT) scheme or a non-CJT (NCJT) scheme. In the CJT scheme, mTRP can perform cooperative communication based on a stable backhaul link, and can 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 communication networks, TRP handover operations may be required between mTRP communication and single TRP (sTRP) communication. A TRP handover operation can refer to a switch from mTRP communication to sTRP communication, and / or a switch from sTRP communication to mTRP communication. Signaling methods are required for TRP handover operations. When a TRP handover operation is indicated, the application time of the TRP handover operation needs to be clearly defined. Summary of the Invention

[0007] Technical issues

[0008] This disclosure aims to provide a method and apparatus for applying switching operations between a single TRP and multiple TRPs in a communication system.

[0009] Technical solution

[0010] According to an exemplary embodiment of the present disclosure, a method for a user equipment (UE) to achieve the above-described objectives may include: performing a first transmit-receive point (TRP) communication with a base station; receiving a first indication of a TRP handover operation from the base station; determining an application time for the TRP handover operation based on the first indication; performing a TRP handover operation from the first TRP communication to the second TRP communication during the application time; and performing a second TRP communication with the base station, wherein when the first TRP communication is a multi-TRP (mTRP) communication, the second TRP communication is a single-TRP (sTRP) communication, and when the first TRP communication is an sTRP communication, the second TRP communication is an mTRP communication.

[0011] The above method may further include: receiving information about the TRP handover gap from the base station, wherein the application time is after the TRP handover gap starting from the first indicated reception time.

[0012] The application time can be after the UE sends its response to the first indication to the base station.

[0013] A second TRP communication can be performed after the TRP handover operation is executed until a second indication of the TRP handover operation or a Transport Configuration Indicator (TCI) status update indication is received.

[0014] The above method may further include: receiving information about the duration of the TRP handover from the base station, wherein the second TRP communication following the TRP handover operation is performed during the TRP handover duration.

[0015] The above method may further include: receiving repeat configuration information for TRP handover operation from a base station, wherein the second TRP communication following the TRP handover operation is performed during the repeat duration indicated by the repeat configuration information.

[0016] The above method may further include: receiving a TCI status update indication from a base station; and updating the TCI status for one or more TRPs performing the second TRP communication, wherein the TCI status of the remaining TRPs among the plurality of TRPs performing the first TRP communication, other than the one or more TRPs mentioned above, is not updated.

[0017] The above method may further include: receiving TCI status information from a base station, wherein the application time is after the beam application time of the TCI status information.

[0018] According to an exemplary embodiment of the present disclosure, a method for a base station to achieve the above-described objectives may include: performing a first transmit-receive point (TRP) communication with a user equipment (UE); sending a first indication of a TRP handover operation to the UE; determining an application time for the TRP handover operation based on the first indication; performing a TRP handover operation from the first TRP communication to the second TRP communication during the application time; and performing a second TRP communication with the UE, wherein when the first TRP communication is a multi-TRP (mTRP) communication, the second TRP communication is a single-TRP (sTRP) communication, and when the first TRP communication is an sTRP communication, the second TRP communication is an mTRP communication.

[0019] The above method may further include: sending information about the TRP handover gap to the UE, wherein the application time is after the TRP handover gap starting from the first indicated reception time.

[0020] The application time can be after the base station receives the response to the first indication from the UE.

[0021] A second TRP communication can be performed after the TRP handover operation is executed until a second indication of the TRP handover operation or a Transport Configuration Indicator (TCI) status update indication is received.

[0022] The above method may further include: sending information about the TRP handover duration to the UE, wherein the second TRP communication following the TRP handover operation is performed during the TRP handover duration.

[0023] The above method may further include: sending repeat configuration information for TRP handover operation to the UE, wherein the second TRP communication after the TRP handover operation is performed during the repeat duration indicated by the repeat configuration information.

[0024] The above method may further include: sending TCI status information to the UE, wherein the application time is after the beam application time of the TCI status information.

[0025] According to an exemplary embodiment of the present disclosure, a user equipment (UE) for achieving the above objectives may include at least one processor, wherein the at least one processor may cause the UE to perform the following operations: communicate with a base station to a first transmit-receive point (TRP); receive a first indication of a TRP handover operation from the base station; determine an application time for the TRP handover operation based on the first indication; perform a TRP handover operation from the first TRP communication to the second TRP communication during the application time; and communicate with the base station to perform a second TRP communication, wherein when the first TRP communication is a multi-TRP (mTRP) communication, the second TRP communication is a single-TRP (sTRP) communication, and when the first TRP communication is an sTRP communication, the second TRP communication is an mTRP communication.

[0026] At least one processor may also cause the UE to perform the following operation: receive information from the base station about the TRP handover gap, wherein the application time is after the TRP handover gap from the first indicated reception time.

[0027] A second TRP communication can be performed after the TRP handover operation is executed until a second indication of the TRP handover operation or a Transport Configuration Indicator (TCI) status update indication is received.

[0028] At least one processor may also enable the UE to perform the following operations: receive information from the base station about the duration of the TRP handover, wherein a second TRP communication following the TRP handover operation is performed during the TRP handover duration.

[0029] At least one processor may also enable the UE to perform the following operations: receive repeat configuration information from the base station for a TRP handover operation, wherein a second TRP communication following the TRP handover operation is performed during the repeat duration indicated by the repeat configuration information.

[0030] Beneficial effects

[0031] According to this disclosure, the base station and / or terminal can switch TRP communication based on an indication of a TRP handover operation. In this case, mTRP communication can be switched to sTRP communication. Alternatively, sTRP communication can be switched to mTRP communication. The application time of the TRP handover operation can be determined based on pre-configured rules. In other words, the application time of the TRP handover operation can be predefined between the base station and the terminal. The base station and / or terminal can perform the TRP handover operation at the application time. Therefore, the ambiguity regarding the application time of the TRP handover operation at the base station and / or terminal can be resolved. Attached Figure Description

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

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

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

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

[0036] Figure 4B This is a block diagram illustrating a first exemplary embodiment of the receiving path.

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

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

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

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

[0041] Figure 9A This is a timing diagram showing the application time of the TRP switching operation.

[0042] Figure 9B This is a timing diagram showing the application time of the TRP switching operation.

[0043] Figure 10 This is a timing diagram illustrating an exemplary embodiment of a communication method based on a Type 1 TRP switching operation.

[0044] Figure 11 This is a timing diagram illustrating an exemplary embodiment of a communication method based on a type 2 TRP switching operation. Detailed Implementation

[0045] Because this disclosure can be modified in various ways and has multiple forms, specific exemplary embodiments will be shown in the accompanying drawings and described in detail in the detailed description. However, it should be understood that this disclosure is not intended to be limited to the specific exemplary embodiments, but rather, this disclosure is intended to cover all modifications and alternatives that fall within the spirit and scope of this disclosure.

[0046] Relational terms such as "first," "second," etc., may be used to describe various elements, but these 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 this disclosure, a first component may be referred to as a second component, and a second component may similarly be referred to as a first component. The term "and / or" refers to any one or a combination of multiple related described items.

[0047] In this disclosure, "at least one of A and B" can mean "at least one of A or B" or "at least one of a combination of one or more of A and B". Furthermore, "one or more of A and B" can mean "one or more of A or B" or "one or more of a combination of one or more of A and B".

[0048] In this disclosure, “(re)transmission” can mean “transmission”, “retransmission” or “transmission and retransmission”, “(re)configuration” can mean “configuration”, “reconfiguration” or “configuration and reconfiguration”, “(re)connection” can mean “connection”, “reconnection” or “connection and reconnection”, and “(re)access” can mean “access”, “reaccess” or “access and reaccess”.

[0049] When it is said that one component is "coupled" or "connected" to another component, it should be understood as one component being directly "coupled" or "connected" to the other component, or that there may be another component between them. Conversely, when it is said that one component is "directly coupled" or "directly connected" to another component, it should be understood as that there is no other component between them.

[0050] The terminology used in this disclosure is for describing specific exemplary embodiments only and is not intended to limit the disclosure. Unless the context clearly specifies otherwise, singular expressions include plural expressions as well. In this disclosure, 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, but it should be understood that these terms do not preclude the presence or addition of one or more features, numbers, steps, operations, components, parts, or combinations thereof.

[0051] 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 disclosure pertains. Terms that are commonly used and included in dictionaries shall be understood to have the meaning appropriate to the context in this art. In this specification, terms are not necessarily construed as having a formal meaning unless explicitly defined.

[0052] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In describing the present disclosure, for ease of overall understanding, similar reference numerals denote similar elements throughout the description of the drawings, and repeated descriptions thereof are omitted. Operations according to the exemplary embodiments explicitly described in this disclosure, as well as combinations of exemplary embodiments, extensions of exemplary embodiments, and / or variations of exemplary embodiments, can be performed. Certain operations may be omitted, and the order of operations may be changed.

[0053] Even when an exemplary embodiment describes a method (e.g., transmitting or receiving a signal) to be executed at a first communication node, the corresponding second communication node can also execute a method (e.g., receiving or transmitting a signal) corresponding to the method executed at the first communication node. In other words, when describing the operation of a user equipment (UE), its corresponding base station can execute an operation corresponding to the UE operation. Conversely, when describing the operation of a base station, the corresponding UE can execute an operation corresponding to the base station operation.

[0054] Base stations can be referred to using various terms, such as NodeB, evolved NodeB, next-generation NodeB (gNodeB), gNB, equipment, device, node, communication node, base transceiver station (BTS), radio remote head (RRH), transmit / receive point (TRP), radio unit (RU), roadside unit (RSU), radio transceiver, access point, access node, etc. User equipment (UE) can be referred to using various terms, such as terminal, equipment, device, node, communication node, terminal node, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, on-board unit (OBU), etc.

[0055] In this disclosure, signaling can be one or a combination of higher-layer signaling, MAC signaling, and physical (PHY) signaling. Messages used for higher-layer signaling can be referred to as "high-layer messages" or "high-layer signaling messages." Messages used for MAC signaling can be referred to as "MAC messages" or "MAC signaling messages." Messages used for PHY signaling can be referred to as "PHY messages" or "PHY signaling messages." Higher-layer signaling can refer to the operation of sending and receiving system information (e.g., Master Information Block (MIB), System Information Block (SIB)) and / or RRC messages. MAC signaling can refer to the operation of sending and receiving MAC control unit (CE). PHY signaling can refer to the operation of sending and receiving control information (e.g., downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI)).

[0056] In this disclosure, "configuration of an operation (e.g., a transmission operation)" can refer to configuration information (e.g., cells, parameters) required for the operation and / or signaling indicating information for performing the operation. "Configuration of cells (e.g., parameters)" can refer to signaling of cells. In this disclosure, "signal and / or channel" can refer to a signal, a channel, or both, and "signal" can be used to mean "signal and / or channel".

[0057] The communication networks used in the exemplary embodiments are not limited to those described below, and the exemplary embodiments can be applied to various communication networks (e.g., 4G communication networks, 5G communication networks, and / or 6G communication networks). Here, "communication network" may be used interchangeably with the term "communication system".

[0058] Figure 1 This is a conceptual diagram illustrating a first exemplary embodiment of a communication system.

[0059] like Figure 1 As 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 Serving Gateway (S-GW), a Packet Data Network (PDN) Gateway (P-GW), and a Mobility Management Entity (MME)). When the communication system 100 is a 5G communication system (e.g., an NR system), the core network may include Access and Mobility Management Functions (AMF), User Plane Functions (UPF), Session Management Functions (SMF), etc.

[0060] Multiple communication nodes 110 to 130 can support communication protocols specified in the 3GPP (3rd Generation Partnership Project) standards (e.g., LTE, LTE-A, NR, etc.). These nodes can support Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDM), Filtered OFDM, Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Extended OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier FDMA (SC-FDMA), Non-Orthogonal Multiple Access (NOMA), Generalized Frequency Division Multiple Access (GFDM), Filter Bank Multicarrier (FBMC), Universal Filtered Multicarrier (UFMC), and Space Division Multiple Access (SDMA). Each of these communication nodes can have the following structure.

[0061] Figure 2This is a block diagram illustrating a first exemplary embodiment of a communication node constituting a communication system.

[0062] like Figure 2 As shown, communication node 200 may include at least one processor 210, memory 220, and transceiver 230, which are connected to a network for performing communication. Furthermore, communication node 200 may also include input interface device 240, output interface device 250, storage device 260, etc. The various components included in communication node 200 can communicate with each other as if connected via bus 270.

[0063] 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), graphics processing unit (GPU), or dedicated processor, on which the method according to embodiments of the present disclosure is executed. Each of memory 220 and storage device 260 may be constituted by at least one of volatile storage media and non-volatile storage media. For example, memory 220 may include at least one of read-only memory (ROM) and random access memory (RAM).

[0064] Refer again Figure 1 The communication system 100 may include multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6. The communication system 100 including base stations 110-1, 110-2, 110-3, 120-1, and 120-2, and terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can be referred to as an "access network". Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 can form a macro cell, and each of the fourth base station 120-1 and the fifth base station 120-2 can form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 can all be covered by the cell of the first base station 110-1. Furthermore, the second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 can all be covered by the cell of the second base station 110-2. Additionally, the fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 can all be covered by the cell of the third base station 110-3. Furthermore, the first terminal 130-1 can be covered by the cell of the fourth base station 120-1, and the sixth terminal 130-6 can be covered by the cell of the fifth base station 120-2.

[0065] Here, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can refer to a Node B, an evolved Node B (eNB), a gNB, an Advanced Base Station (ABS), a High Reliability Base Station (HR-BS), a Base Transceiver Station (BTS), a Radio Base Station, a Radio Transceiver, an Access Point, an Access Node, a Radio Access Station (RAS), a Mobile Multi-Hop 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), a Home eNode B (HeNB), a Roadside Unit (RSU), a Radio Remote Header (RRH), a Transmitter Point (TP), a Transmitter Receiver Point (TRP), etc.

[0066] Each of the multiple terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can refer to a user equipment (UE), terminal equipment (TE), advanced mobile station (AMS), high reliability mobile station (HR-MS), terminal, access terminal, mobile terminal, station, subscriber station, mobile station, portable subscriber station, node, equipment, on-board unit (OBU), etc.

[0067] On the other hand, 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. The multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can be interconnected via ideal or non-ideal backhaul and exchange information with each other via ideal or non-ideal backhaul. Furthermore, 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 ideal or non-ideal backhaul. 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 terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6, and transmit signals received from the corresponding terminal 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 to the core network.

[0068] In addition, each of the multiple base stations 110-1, 110-2, 110-3, 120-1 and 120-2 can support multiple-input multiple-output (MIMO) transmission (e.g., single-user MIMO (SU-MIMO), multi-user MIMO (MU-MIMO), massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in unlicensed frequency bands, sidelink communication (e.g., device-to-device (D2D) communication, proximity service (ProSe)), Internet of Things (IoT) communication, dual connectivity (DC), etc. Here, each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, and 130-6 can perform operations corresponding to the operations of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2, as well as operations supported by the plurality of 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 via SU-MIMO, and the fourth terminal 130-4 can receive signals from the second base station 110-2 via SU-MIMO. Alternatively, the second base station 110-2 can transmit signals to the fourth terminal 130-4 and the fifth terminal 130-5 via MU-MIMO, and the fourth terminal 130-4 and the fifth terminal 130-5 can receive signals from the second base station 110-2 via MU-MIMO.

[0069] 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 via CoMP transmission, 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 via CoMP. Furthermore, each of the multiple base stations 110-1, 110-2, 110-3, 120-1, and 120-2 can exchange signals with the corresponding terminals 130-1, 130-2, 130-3, 130-4, 130-5, or 130-6 within its cell coverage area via CA transmission. Each of base stations 110-1, 110-2 and 110-3 can control the sidelink communication between the fourth terminal 130-4 and the fifth terminal 130-5. Therefore, the fourth terminal 130-4 and the fifth terminal 130-5 can perform sidelink communication under the control of the second base station 110-2 and the third base station 110-3, respectively.

[0070] On the other hand, 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 exemplary embodiment of the communication node is shown.

[0071] Figure 3 This is a block diagram illustrating a first exemplary embodiment of a communication node performing communication.

[0072] 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 transmitting processor 311 included in the first communication node 300a can receive data (e.g., data unit) from the data source 310. The transmitting 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 via RRC signaling), MAC control information (e.g., MAC CE), or PHY control information (e.g., DCI, SCI).

[0073] The transmitter processor 311 can generate data symbols by performing processing operations on data (e.g., encoding operations, symbol mapping operations, etc.). The transmitter processor 311 can generate control symbols by performing processing operations on control information (e.g., encoding operations, symbol mapping operations, etc.). Furthermore, the transmitter processor 311 can generate synchronization / reference symbols for synchronization signals and / or reference signals.

[0074] 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 the modulators (MODs) included in transceivers 313a to 313t. The modulators 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.

[0075] The signal transmitted by the first communication node 300a can be received at antennas 364a to 364r of the second communication node 300b. The signals received at antennas 364a to 364r can be provided to demodulators (DEMODs) included in transceivers 363a to 363r. The demodulators (DEMODs) can obtain samples by performing processing operations on the signal (e.g., filtering, amplification, down-conversion, digital conversion, etc.). The demodulators can perform additional processing operations on the samples to obtain 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.

[0076] On the other hand, the second communication node 300b can transmit signals to the first communication node 300a. The transmitting processor 368 included in the second communication node 300b can receive data (e.g., data units) from the data source 367 and perform processing operations on the data to generate data symbols. The transmitting processor 368 can receive control information from the controller 366 and perform processing operations on the control information to generate control symbols. Furthermore, the transmitting processor 368 can generate reference symbols by performing processing operations on a reference signal.

[0077] 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 the modulators (MODs) included in transceivers 363a to 363t. The modulators 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 363a to 363t can be transmitted via antennas 364a to 364t.

[0078] The signal transmitted by the second communication node 300b can be received at antennas 314a to 314r of the first communication node 300a. The signals received at antennas 314a to 314r can be provided to demodulators (DEMODs) included in transceivers 313a to 313r. The demodulators can obtain samples by performing processing operations on the signals (e.g., filtering, amplification, down-conversion, digital conversion, etc.). The demodulators can perform additional processing operations on the samples to obtain 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 data sink 318 and controller 316. For example, data can be provided to data sink 318, and control information can be provided to controller 316.

[0079] 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, and 369, and the controllers 316 and 366 shown may be Figure 2 The processor 210 shown can be used to perform the methods described in this disclosure.

[0080] Figure 4A This is a block diagram illustrating a first exemplary embodiment of the transmission path. Figure 4B This is a block diagram illustrating a first exemplary embodiment of the receiving path.

[0081] like Figure 4A and Figure 4B As shown, the transmitting path 410 can be implemented in the communication node transmitting the signal, and the receiving path 420 can be implemented in the communication node receiving the signal. The transmitting path 410 may include a channel coding and modulation block 411, a serial-to-parallel (S-to-P) block 412, an N-point inverse fast Fourier transform (N-point IFFT) block 413, a parallel-to-serial (P-to-S) block 414, a cyclic prefix (CP) addition block 415, and an up-converter (UC) 416. The receiving path 420 may include a down-converter (DC) 421, a CP removal block 422, an S-to-P block 423, an N-point FFT block 424, a P-to-S block 425, and a channel decoding and demodulation block 426. Here, N can be a natural number.

[0082] In transmission path 410, information bits can be input to channel coding and modulation block 411. Channel coding and modulation block 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 (OPSK), quadrature amplitude modulation (QAM), etc.) on the information bits. The output of channel coding and modulation block 411 can be a sequence of modulation symbols.

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

[0084] The CP adder block 415 inserts a CP into the signal. The UC 416 upconverts the frequency of the output of the CP adder block 415 to an radio frequency (RF) frequency. Furthermore, the output of the CP adder block 415 can be filtered in baseband before upconversion.

[0085] The signal transmitted from the transmitting path 410 can be input to the receiving path 420. Operations in the receiving path 420 can be the inverse of operations in the transmitting path 410. DC 421 can down-convert the frequency of the received signal to the baseband frequency. CP removal block 422 can remove CP from the signal. The output of CP removal block 422 can be a serial signal. S-to-P block 423 can convert the serial signal into a parallel signal. N-point FFT block 424 can generate N parallel signals by executing an FFT algorithm. P-to-S block 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 data by performing decoding operations on the results of the demodulation operations.

[0086] exist Figure 4A and Figure 4B In this context, the Discrete Fourier Transform (DFT) and Inverse DFT (IDFT) can be used instead of FFT and IFFT. Figure 4A and Figure 4B Each block (e.g., component) in the document can be implemented by at least one of hardware, software, or firmware. For example, Figure 4A and Figure 4B Some blocks can be implemented in software, while others can be implemented in hardware or a combination of hardware and software. Figure 4A and Figure 4BIn this context, a block can be subdivided into multiple blocks, multiple blocks can be combined into one block, some blocks can be omitted, and blocks that support other functions can be added.

[0087] Figure 5 This is a conceptual diagram illustrating a first exemplary embodiment of a system frame in a communication system.

[0088] like Figure 5 As shown, time resources in a communication system can be divided into frames. For example, system frames in a communication system can be configured consecutively in the time domain. The length of a system frame can be 10 milliseconds (ms). The system frame number (SFN) can be set to one of #0 to #1023. In this case, 1024 system frames can be repeated in the time domain of the communication system. For example, the SFN of a system frame after system frame #1023 can be #0.

[0089] A system frame can include two half-frames. The length of a half-frame can be 5 ms. The half-frame located in the beginning region of the system frame can be called "half-frame #0", and the half-frame located in the end region of the system frame can be called "half-frame #1". A system frame can include 10 subframes. The length of a subframe can be 1 ms. The 10 subframes within a system frame can be called subframes #0-#9.

[0090] Figure 6 This is a conceptual diagram illustrating a first exemplary embodiment of a subframe in a communication system.

[0091] like Figure 6 As shown, a subframe can include n time slots, where n can be a natural number. Therefore, a subframe can consist of one or more time slots.

[0092] Figure 7 This is a conceptual diagram illustrating a first exemplary embodiment of a time slot in a communication system.

[0093] 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 and length of the symbols included in the time slot. Alternatively, the length of a time slot can vary based on a set of parameters.

[0094] The set of parameters applied to the physical signals and channels in a communication system can be 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 illustrates a first exemplary embodiment of a method for configuring the parameter set of a CP-OFDM-based communication system. Depending on the frequency band in which the communication system operates, at least some of the parameter sets in Table 1 can be supported. Furthermore, the communication system can support parameter sets not listed in Table 1.

[0095] [Table 1]

[0096]

[0097] When the subcarrier spacing is 15 kHz (e.g., μ = 0), the slot length can be 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 can be 0.5 ms. In this case, a system frame can include 20 slots.

[0098] When the subcarrier spacing is 60 kHz (e.g., μ = 2), the slot length can be 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 can be 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 can be 0.0625 ms. In this case, a system frame can include 160 slots.

[0099] 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".

[0100] The time slot format can be semi-statically configured via higher-layer signaling (e.g., RRC signaling). Information indicating the semi-static time slot format can be included in the system information, and the semi-static time slot format can be configured in a cell-specific manner. Furthermore, the semi-static time slot format can also 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 rewritten 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 time slot format indicator (SFI) included in the DCI). The semi-statically configured time slot format can be rewritten by the dynamically indicated time slot format. For example, the semi-statically configured flexible symbols can be rewritten as downlink or uplink symbols by the SFI.

[0101] 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 disclosure, a control channel may refer to PDCCH, PUCCH, or PSCCH, and a data channel may refer to PDSCH, PUSCH, or PSSCH.

[0102] Figure 8 This is a conceptual diagram illustrating a first exemplary embodiment of time-frequency resources in a communication system.

[0103] like Figure 8 As shown, a resource consisting of one OFDM symbol on the time axis and one subcarrier on the frequency axis can be defined as a "resource element (RE)". A resource consisting of one OFDM symbol on the time axis and K subcarriers on the frequency axis can be defined as a "resource element group (REG)". A REG can 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 slot shown, N can be 14. N OFDM symbols can be used as the basic unit for resource allocation in the time domain.

[0104] In this disclosure, RB may refer to a common RB (CRB). Alternatively, RB may refer to a physical RB (PRB) or a virtual RB (VRB). In a communication system, CRB may refer to an RB that forms a set of consecutive RBs (e.g., a common RB grid) based on a reference frequency (e.g., point A). Carriers and / or portions of bandwidth may be mapped onto the common RB grid. That is, carriers and / or portions of bandwidth may be configured with CRBs. The RB or CRB constituting a portion of the bandwidth may be referred to as a PRB, and the CRB index may be appropriately converted to a PRB index within the portion of the bandwidth.

[0105] Downlink data can be transmitted via PDSCH. The base station can send 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) for transmitting / receiving PDSCH, PDSCH timing resource information, PDSCH frequency resource information, and PDSCH feedback resource information. PDSCH can refer to the radio resources in which downlink data is transmitted and received. Alternatively, PDSCH can refer to the downlink data itself. PDCCH can refer to the radio resources in which downlink control information (e.g., DCI) is transmitted and received. Alternatively, PDCCH can refer to the downlink control information itself.

[0106] The terminal can perform monitoring operations on the PDCCH to receive PDSCH sent from the base station. The base station can use higher-layer messages (e.g., Radio Resource Control (RRC) messages) to notify 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.

[0107] CORESET information may include PDCCH DMRS 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, meaning it is the region where DCI can be transmitted. PDCCH timing can also be called 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 the PDCCH timing can be indicated in symbols. In the frequency domain, the size of the PDCCH timing can be indicated in RBs (e.g., PRB units or CRB units).

[0108] Search space information may include a CORESET identifier (ID) associated with the search space, the PDCCH monitoring period, and / or the PDCCH monitoring offset. The PDCCH monitoring period and offset may be indicated in time slots. Additionally, the search space information may include an index of the symbol at which the PDCCH monitoring operation began.

[0109] A base station can configure a portion bandwidth (BWP) for downlink communication. Each terminal can be configured with a different BWP. The base station can use higher-layer signaling to notify the terminal of the BWP configuration information. Higher-layer signaling can refer to the transmission of system information and / or the transmission of RRC messages. 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 BWP based on the received 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) element (CE), or a DCI to send the configuration information of the activated BWP to the terminal. The base station can use the activated BWP to perform downlink communication. The terminal can identify the activated BWP by receiving configuration information from the base station and perform downlink reception operations on the activated BWP.

[0110] On the other hand, communication systems (e.g., NR, 5G, or 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., multiple TRP (mTRP) technologies and / or single TRP (sTRP) technologies). Communication systems supporting TRP technologies can be referred to as TRP systems (e.g., mTRP systems and / or sTRP systems). In this disclosure, the meaning of "TRP" can include "sTRP" and / or "mTRP," and "TRP" can refer to either "sTRP" or "mTRP" depending on the context. A TRP can refer to an antenna set, antenna group, and / or antenna array. A TRP can be associated with a CORESET and / or a beam (e.g., a beam group).

[0111] mTRP technology falls under the category of MIMO technology. mTRP can possess characteristics of macrocells, small cells, picocells, and / or femtocells (e.g., cell-level characteristics). mTRP can perform data transmission to terminals. In situations where channel conditions are uneven due to obstacles and / or interference (e.g., links), mTRP can mitigate the effects of obstacles and / or interference. mTRP can improve the data transmission rate of terminals located at the cell edge.

[0112] Communication based on mTRPs can be performed using either Coherent Joint Transport (CJT) or Non-Coherent Joint Transport (NCJT) schemes. In CJT, the base station knows the channel information between each TRP and the terminal and can perform preprocessing operations on the data based on this information. However, this increases the overhead of channel information transmission and introduces synchronization constraints between TRPs. In NCJT, the base station does not need to know the channel information between each TRP and the terminal. The mTRPs can send data to the terminal without performing preprocessing operations such as phase compensation. Therefore, the complexity of the NCJT scheme is lower than that of the CJT scheme.

[0113] NCJT-based mTRP communication can be performed using either a single DCI scheme or a multi-DCI scheme. In a single DCI scheme, the PDSCH sent by an mTRP can be scheduled by a single DCI. This single DCI can be sent by one of the TRPs within the mTRP. In a multi-DCI scheme, the PDSCH sent by each TRP can be scheduled by the corresponding DCI. For example, the first PDSCH sent by the first TRP can be scheduled by the first DCI sent by the first TRP, and the second PDSCH sent by the second TRP can be scheduled by the second DCI sent by the second TRP. In other words, multiple PDSCHs can be scheduled using multiple DCIs.

[0114] In a single SCI scheme, the terminal can expect to receive PDSCHs transmitted by different TRPs through different layers while using the same time and frequency resources. Alternatively, the terminal can expect to receive PDSCHs transmitted by different TRPs through different time resources (e.g., different time zones) while using the same frequency resources and the same layer. Alternatively, the terminal can expect to receive PDSCHs transmitted by different TRPs through different frequency resources (e.g., different frequency zones) while using the same time resources and the same layer.

[0115] In a multi-DCI scheme, PDSCH scheduling for each TRP can be performed by a separate 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 Transmission Configuration Indication (TCI) status information for the PDSCH.

[0116] 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 indicate the configuration of the QCL (Quadruple Address Colocation). From the perspective of uplink (UL) communication, the TCI state configuration can indicate the configuration of the spatial filter. A unified TCI state can indicate (e.g., configure) a common beam, regardless of whether it is DL or UL communication. Alternatively, a unified TCI state can indicate (e.g., configure) a common beam for each of DL and UL communications. The unified TCI can be referred to as "UTCI".

[0117] To enhance the reliability and / or robustness of mTRP communication, improvements such as PDCCH enhancement can be applied. PDCCH enhancement deployment scenarios can be categorized into single-frequency networks (SFN) and non-SFN.

[0118] In the SFN scheme, different TRPs or different panels can transmit the same PDCCH using the same resources (e.g., the same time resources, the same frequency resources, and / or the same spatial resources). In other words, all TRPs or all panels can transmit PDCCH using the same DMRS configuration, the same DMRS location, and / or the same DMRS sequence. In this case, from the perspective of the TRP or panel receiving, the TCI states can be implicitly configured differently. The exemplary embodiments described above can be performed based on multiple TCI states of CORESET. Ideal or near-ideal backhaul synchronization constraints may exist between TRPs.

[0119] In the NSFN scheme, the 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 number of coded bits, equal to the number of bits transmitted through a PDCCH generated by each TRP, can be divided among TRPs, and TRP-specific bits (e.g., coded bits) can be transmitted through different PDCCH candidates for each TRP. This scheme can correspond to a PDCCH transmission scheme based on sTRP.

[0120] In the mTRP-based PDCCH repetition scheme, PDCCHs can be replicated according to the number of TRPs, and PDCCHs can be sent in the same search space (e.g., search spaces with the same index) within different search space sets, each search space having the same number of PDCCH candidates. In this case, the search space sets can exist within the same CORESET or in different CORESETs. Since a TCI state can be associated with multiple CORESETs, when PDCCHs are sent from different search spaces within the same CORESET, only one TCI state can be indicated (e.g., configured) for PDCCHs sent from different search spaces. In this scenario, a terminal can receive one PDCCH from a TRP at a specific time.

[0121] When PDCCHs are transmitted from the same search space within different CORESETs, the terminal implicitly anticipates receiving PDCCHs from either 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 partitioned into as many PDCCHs as the number of TRPs, and the partitioned PDCCHs can be transmitted in different PDCCH candidates. In this case, the aggregation level and the merge aggregation level can be the same. In the exemplary embodiments described above, PDCCH candidates can be assigned to different CORESETs. The payload size of the final distributed PDCCH combination can be the same as the payload size of the PDCCH transmitted from the sTRP. Therefore, in terms of decoding complexity, the sTRP-based PDCCH transmission scheme can be more advantageous than the mTRP-based PDCCH repetition scheme.

[0122] The terminal can perform mTRP communication or sTRP communication with the base station. mTRP communication between the terminal and the base station can be performed via an mTRP associated with the base station. sTRP communication between the terminal and the base station can be performed via an sTRP associated with the base station. mTRP communication can refer to first TRP communication, and sTRP communication can refer to second TRP communication. Alternatively, mTRP communication can refer to second TRP communication, and sTRP communication can refer to first TRP communication. Expressing "the terminal performs first TRP communication with the base station" can mean that the terminal performs mTRP or sTRP communication with the base station via one or more TRPs associated with the base station. Expressing "the terminal performs second TRP communication with the base station" can mean that the terminal performs sTRP or mTRP communication with the base station via one or more TRPs associated with the base station.

[0123] In a communication system, a unified TCI framework can be supported. The base station can use RRC signaling to send information about the TCI state pool (e.g., a pool list) to the terminal. The terminal can receive the TCI state pool (e.g., a pool list) information via the base station's RRC signaling. The base station can configure the type information of the TCI state for the terminal. The type information can indicate a joint DL / UL beam indication or a separate DL / UL beam indication. A joint DL / UL beam indication can be referred to as a "joint indication" or "joint type." A separate DL / UL beam indication can be referred to as a "separate indication" or "separate type."

[0124] When configuring a joint type (e.g., joint indication), TCI states for DL ​​and UL can be configured (e.g., a single TCI state). In other words, the DL TCI state configuration and the UL TCI state configuration can be the same. The terminal can expect that the TCI state indicated by the cells included in the PDSCH configuration information will be applied to both DL (e.g., DL signal / channel) and UL (e.g., UL signal / channel). The term "signal / channel" can refer to a signal and / or a channel. When configuring a separate type (e.g., separate indication), TCI states for DL ​​and UL can be configured separately. In other words, the DL TCI state configuration can be distinguished from the UL TCI state configuration. The terminal can expect that the UL TCI state indicated by the cells included in the UL BWP configuration information will be applied to UL (e.g., UL signal / channel). UL signal / channel can include PUSCH, PUCCH, and / or SRS.

[0125] After configuring (e.g., indicating) the TCI state pool (e.g., pool list) via RRC signaling, the base station can use DCI (e.g., DCI signaling) to indicate the TCI states (e.g., the application of TCI states). Due to constraints on the DCI size (e.g., the bits of the DCI field), the base station can preferentially activate candidate TCI states using MAC signaling (e.g., MAC CE signaling). In other words, up to a certain number (e.g., a maximum number) of candidate TCI states that can be indicated or configured via DCI can be preferentially activated by MAC CE.

[0126] For an active candidate TCI state, the DCI can include code points corresponding to a single TCI state or two TCI states, depending on the TCI state type (e.g., combined type or individual type). When a combined type is configured, code points corresponding to a single TCI state can be transmitted via the DCI. When an individual type is configured, code points corresponding to two TCI states can be transmitted via the DCI. A unified TCI (e.g., a unified TCI framework) designed for sTRP operations (e.g., sTRP communication) can be applied to (e.g., extended to) mTRP operations (e.g., mTRP communication).

[0127] A unified TCI state framework can be configured for (e.g., applied to) sTRP and mTRP operations. Handover operations between sTRP and mTRP operations (e.g., dynamic handover operations) can be supported. The handover operation between sTRP and mTRP operations can be referred to as a "TRP handover operation." A TRP handover operation can refer to a "handover operation from mTRP to sTRP," a "handover operation from sTRP to mTRP," and / or a "handover operation from a specific TRP to another TRP." For configuring the TCI state of the PDSCH, a TCI selection field can be introduced. The DCI can include a TCI selection field. The TCI selection field can be used not only to configure the receive beam of the PDSCH in the terminal (e.g., TCI state) but also for TRP handover operations (e.g., indication of TRP handover operations). Not only PDSCH, but other signals / channels also require TRP handover operations. The TCI fields included in the DCI can be used to configure TCI states and / or TRP handover operations (e.g., indication of TRP handover operations). In other words, the TCI field included in DCI may or may not be used for TRP switching operations.

[0128] Base stations can proactively select (e.g., use) sTRP or mTRP operations based on the channel environment. In this case, resource utilization efficiency is improved. Not only PDSCH, but other signals / channels (e.g., other DL signals / channels) also require TRP handover operations.

[0129] In a communication system, TRP handover operations can be supported. A TRP handover operation can refer to a dynamic TRP handover operation. The base station can send a TRP handover operation indication to the terminal, which can be sent using at least one of RRC messages, MAC CE, or DCI. The terminal can receive the TRP handover operation indication from the base station. The base station and / or the terminal can perform a TRP handover operation based on the TRP handover operation indication. For example, the base station and / or the terminal can switch from mTRP communication to sTRP communication and can perform sTRP communication. Alternatively, the base station and / or the terminal can switch from sTRP communication to mTRP communication and can perform mTRP communication. The TRP handover operation indication can refer to a TRP handover operation trigger command.

[0130] When instructing a TRP handover operation, it may be necessary to define the time for performing the TRP handover operation (e.g., application time). "Time" can be interpreted as "duration" or "point in time" depending on the context. As in beam application time, an application time (e.g., physical time) may be required for performing the TRP handover operation. The TRP handover operation can be performed after the instruction to perform the TRP handover operation has been received at the acknowledgment terminal. In this case, a time may be needed to confirm receipt of the instruction to perform the TRP handover operation before it is executed.

[0131] The operation of communication nodes (e.g., base stations and / or terminals) may vary depending on parameters related to the application of the unified TCI state and / or the application time of TRP handover operations. In this case, issues may arise regarding the execution of TRP handover operations. It may be necessary to define the start time, application duration, and / or end time of the TRP handover operation.

[0132] A DCI may include a TCI selection field. The TCI selection field can be used to indicate the TCI status of a PDSCH (e.g., TCI configuration). A DCI may include a TCI field and a TCI selection field. The TCI selection field can be configured independently of the TCI field. The TCI field can indicate the TCI code point used to indicate the TCI status (e.g., information about the TCI status). The TCI selection field can be applied to a PDSCH scheduled by a DCI that includes a TCI field (e.g., a PDCCH). The TCI selection field can be used to indicate the TCI status and / or TRP handover operation associated with PDSCH reception.

[0133] Depending on the channel environment, the base station can actively select (e.g., use) sTRP communication or mTRP communication. In this case, resource utilization efficiency can be improved. TRP handover operations can be applied not only to PDSCH transmission but also to other channel transmissions. A channel can refer to a DL channel and / or a UL channel. A channel can be interpreted as "channel," "signal," or "channel and signal" depending on the context. TCI and TCI states can each be interpreted as unified TCI and unified TCI state depending on the context.

[0134] The terminal may send a request for a TRP handover operation to the base station based on the state of the DL channel and / or UL channel. The base station may receive the request for the TRP handover operation from the terminal. The base station may consider the terminal's request and send an indication of the TRP handover operation to the terminal. Alternatively, the terminal may not send a request for the TRP handover operation to the base station, and the base station may send an indication of the TRP handover operation to the terminal without considering the terminal's request. The terminal may receive the indication of the TRP handover operation from the base station and may perform the TRP handover operation based on the indication. The base station and / or the terminal may determine the application time point (e.g., application time) based on the indication of the TRP handover operation and may perform the TRP handover operation at the application time point. The application time (e.g., execution time) of the TRP handover operation may be defined as follows. The base station and / or the terminal may determine the application time of the TRP handover operation based on the following method and may perform the TRP handover operation at the application time.

[0135] ● Application time of TRP switching operation

[0136] Figure 9A This is a timing diagram showing the application time of the TRP switching operation.

[0137] like Figure 9A As shown, the terminal can communicate via TRP #1 and TRP #2. In other words, the terminal can perform mTRP communication. TRP #1 and TRP #2 can be associated with a base station. The base station can send a TRP handover operation indication to the terminal via signaling. The TRP handover operation indication can be sent via either TRP #1 or TRP #2. The terminal can receive the TRP handover operation indication from the base station.

[0138] When the TRP handover operation does not require a specific timeframe (e.g., a delay or required time), the terminal can perform the TRP handover operation after receiving the TRP handover instruction. In other words, the TRP handover operation can be performed immediately after receiving the TRP handover instruction. In this case, the TRP handover operation can be performed at time T-1A. Time T-1A can correspond to the end time of reception of the TRP handover instruction (e.g., the end-of-reception symbol). Alternatively, time T-1A can correspond to the start symbol, any symbol, or the last symbol within the time slot (or subframe) in which the TRP handover instruction is received. Any symbol can be configured between the terminal and the base station. For example, the base station can send information about any symbol to the terminal via signaling. When the TRP handover operation is complete, communication between the terminal and the base station can be performed via the handed-over TRP (e.g., sTRP or mTRP).

[0139] The application of TRP handover operations may take time. For example, time may be attributed to factors such as time spent on beam reconfiguration, signaling processing, and latency in physical components. When a terminal performs mTRP communication using different beams (e.g., different receive beams and / or different transmit beams), the application of TRP handover operations (e.g., a TRP handover from mTRP communication to sTRP communication) may take time. Similarly, the application of TRP handover operations may take time when a TRP (e.g., a TRP connected to a terminal) attempts to perform communication using different beams (e.g., different receive beams and / or different transmit beams).

[0140] When a TRP handover operation is required, the terminal may not expect to perform communication (e.g., receive and / or transmit operations) during the TRP handover gap (e.g., the time gap used for TRP handover) starting from the reception time indicated by the TRP handover operation. In other words, the terminal cannot perform communication in the resources (e.g., time resources, frequency resources, and physical channels) corresponding to the TRP handover gap.

[0141] The TRP handover gap can be predefined in the technical specifications. Alternatively, the base station and / or the terminal can determine and use the determined TRP handover gap. For example, the terminal can send UE capability information (e.g., a UE capability report) containing information about the application time of the TRP handover operation to the base station. The application time of the TRP handover operation can vary depending on the UE capability (e.g., the terminal's capability). The base station can receive the UE capability information from the terminal, identify the application time of the TRP handover operation included in the UE capability information, and determine the TRP handover gap by taking the application time of the TRP handover operation into account. Alternatively, the base station can determine the TRP handover gap without considering the UE capability information. The base station can send the TRP handover gap information to the terminal via signaling. The terminal can receive information about the TRP handover gap from the base station. The base station and / or the terminal can determine the application time of the TRP handover operation based on the TRP handover operation indication and the TRP handover gap.

[0142] Information regarding the TRP handover gap can be cell-wide information (e.g., cell-specific information) or UE-specific information. This information may include system information and / or RRC messages commonly applied within the cell. Alternatively, it may be included in the MAC CE and / or DCI applied to a specific terminal. The TRP handover gap can be configured in units of symbols, time slots, or specific times (e.g., milliseconds (ms)). The TRP handover gap may be referred to as the TRP handover offset.

[0143] exist Figure 9A In an exemplary embodiment, when the timing of the TRP handover operation needs to be applied, the terminal may perform the TRP handover operation after a TRP handover gap starting from the reception time indicated by the TRP handover operation. In other words, the terminal may perform the TRP handover operation at time T-1B. The base station may anticipate that the terminal will perform the TRP handover operation after a TRP handover gap starting from the reception time indicated by the TRP handover operation. The TRP handover gap may begin from the reception end time indicated by the TRP handover operation (e.g., the reception end symbol). Alternatively, the TRP handover gap may begin from the start symbol, any symbol, or the last symbol within the time slot (e.g., subframe) where the TRP handover operation indication is received. Any symbol may be configured between the terminal and the base station. For example, the base station may send information about any symbol to the terminal via signaling. When the TRP handover operation is completed, communication between the terminal and the base station may be performed via the handed-over TRP (e.g., sTRP or mTRP).

[0144] Figure 9B This is a timing diagram showing the application time of the TRP switching operation.

[0145] like Figure 9B As shown, the terminal can communicate via TRP #1 and TRP #2. In other words, the terminal can perform mTRP communication. TRP #1 and TRP #2 can be associated with a base station. The base station can send a TRP handover operation indication to the terminal via signaling. The TRP handover operation indication can be sent via either TRP #1 or TRP #2. The terminal can receive the TRP handover operation indication from the base station. When the TRP handover operation indication is successfully received, the terminal can send a response to the indication (e.g., a TRP handover response) to the base station.

[0146] A TRP handover response can be a Hybrid Automatic Repeat Request (HARQ)-Acknowledgement (ACK) indicating a TRP handover operation. The TRP handover response can be sent via at least one of TRP #1 or TRP #2. The TRP handover response can be sent on either PUCCH or PUSCH. The base station can receive the TRP handover response from the terminal. When the base station receives the TRP handover response from the terminal, it can determine that the indication of the TRP handover operation has been successfully received at the terminal. The terminal can perform a TRP handover operation after sending the TRP handover response. The base station can perform a TRP handover operation after receiving the TRP handover response.

[0147] The TRP handover operation indication may not be successfully received at the terminal. For example, reception of the TRP handover operation indication may fail due to channel conditions. When configured to perform the TRP handover operation after the transmission and reception of the TRP handover operation indication, a terminal that does not receive the TRP handover operation indication will not perform the TRP handover operation, but the base station that sent the TRP handover operation indication may expect the terminal to perform the TRP handover operation. In this case, the base station will perform the TRP handover operation after sending the TRP handover operation indication. In other words, the base station will communicate with the handover-assigned TRP (sTRP or mTRP). In the above scenario, the TRP communication performed by the terminal (e.g., mTRP communication) will differ from the TRP communication performed by the base station (e.g., sTRP communication), and communication between the terminal and the base station will fail. To prevent the above problem, the TRP handover operation can be configured to be performed after the transmission and reception of the TRP handover response.

[0148] When the TRP handover operation time is not required, the terminal can perform the TRP handover operation at the time the TRP handover response is sent (e.g., at the end symbol). In other words, the TRP handover operation can be performed immediately after sending the TRP handover response. Alternatively, the terminal can perform the TRP handover operation at the start symbol, any symbol, or the last symbol within the time slot (e.g., subframe) where the TRP handover response is sent. Any symbol can be configured between the terminal and the base station. For example, the base station can send information about any symbol to the terminal via signaling. When the TRP handover operation time is not required, the TRP handover operation can be performed at time T-2A. In other words, the terminal and / or the base station can perform the TRP handover operation at time T-2A and can perform communication via the handed-over TRP (e.g., sTRP or mTRP).

[0149] When a TRP handover operation is required, the terminal may perform the TRP handover operation after the TRP handover gap starting from the time the TRP handover response is sent (e.g., the end symbol is sent). The terminal may perform the TRP handover operation after the TRP handover gap starting from the start symbol, any symbol, or the last symbol within the time slot (e.g., subframe) where the TRP handover response was sent. Any symbol can be configured between the terminal and the base station. For example, the base station can send information about any symbol to the terminal via signaling. The terminal and / or the base station are not expected to perform communication during the TRP handover gap. When a TRP handover operation is required, the TRP handover operation may be performed at time T-2B. In other words, the terminal and / or the base station may perform the TRP handover operation at time T-2B and may perform communication via the handed-over TRP (e.g., sTRP or mTRP).

[0150] The timing of the TRP switching operation (e.g., the TRP switching interval) can be applied to other exemplary embodiments of this disclosure (e.g., the application indication time, the application triggering time).

[0151] ● Types of TRP switching operations

[0152] TRP switching operation types can be classified as shown in Table 2 below.

[0153] [Table 2]

[0154]

[0155] TRP handover operations (e.g., operations indicated by a TRP handover operation) can be performed based on type 1, type 2, or type 3. Regardless of the type defined in Table 2, the initialization of a TRP handover operation can be performed based on an activation or deactivation command for a unified TCI state. The initialization of a TRP handover operation can refer to applying the indicated TCI state (e.g., the changed TCI state) to the post-handover TRP when a change in the terminal's TCI state is indicated (configured) to the terminal.

[0156] The base station can determine the type of TRP handover operation (e.g., type 1, type 2, or type 3) and can send information about the TRP handover operation type to the terminal via signaling (e.g., RRC signaling, MAC signaling, and / or PHY signaling). The terminal can receive information about the type of TRP handover operation from the base station. In another method, the terminal can send information about the supported types of TRP handover operations to the base station. Information about the supported types can be included in UE capability information (e.g., UE capability report). In other words, the terminal can send information indicating whether a type of TRP handover operation is supported to the base station. The base station can receive information about the supported types from the terminal (e.g., information indicating whether a type of TRP handover operation is supported) and can consider this information to determine the type of TRP handover operation. The base station can send information about the type of TRP handover operation to the terminal via signaling (e.g., RRC signaling, MAC signaling, and / or PHY signaling). The terminal can receive information about the type of TRP handover operation from the base station.

[0157] The terminal can send preferred values ​​for parameters related to the type of TRP handover operation (e.g., TRP handover duration, TRP handover repetition duration, TRP handover repetition period, and number of TRP handover repetitions) to the base station. The base station can receive these preferred values ​​from the terminal and determine the parameters related to the type of TRP handover operation based on them. The base station can then send the determined parameters to the terminal via signaling. The determined parameters can be sent along with information about the type associated with those parameters. The terminal can receive the determined parameters from the base station.

[0158] - Type 1 of TRP switching operation

[0159] The base station may send a first indication (e.g., a trigger command) for a TRP handover operation to the terminal. The terminal may receive the first indication for the TRP handover operation from the base station. The base station and / or the terminal may perform a TRP handover operation based on the first indication. Communication between the base station and the terminal may be performed via the handover-transferred TRP (e.g., sTRP or mTRP). Communication between the base station and the terminal may be performed via the handover-transferred TRP (e.g., sTRP or mTRP) until additional indications are sent or received.

[0160] The base station can send a second indication of the TRP handover operation to the terminal. This second indication can be distinguished from the first indication of the TRP handover operation. Upon receiving the second indication, the terminal can terminate communication via the new TRP based on the first indication. The base station can perform a TRP handover operation based on the second indication and can also perform communication via the new TRP. In other words, based on the second indication, communication between the base station and the terminal can be performed via the new TRP (e.g., sTRP or mTRP).

[0161] In another example, the base station can send TCI state change information (e.g., update information) to the terminal. The terminal can receive the TCI state change information from the base station. Upon receiving the TCI state change information, the terminal can terminate communication via the new TRP indicated by the TRP handover operation. When the TCI state change information is sent, the base station can determine that communication via the new TRP indicated by the TRP handover operation has been terminated. In other words, the TRP handover operation can be initiated. The update of the TCI state can refer to a change in the TCI state used to configure the terminal beam (e.g., configure the receive beam and / or transmit beam). Since the update of the TCI state implies a change in the channel state, communication based on the TRP handover operation indication can be terminated.

[0162] Figure 10 This is a timing diagram illustrating an exemplary embodiment of a communication method based on a Type 1 TRP switching operation.

[0163] like Figure 10 As shown, the base station can send a Unified TCI (UTCI) activation indication to the terminal, and the terminal can receive the UTCI activation indication from the base station. Communication between the base station and the terminal can be performed based on the activated UTCI. For example, the terminal can perform communication via TRP #1 and TRP #2. In other words, the terminal can perform mTRP communication. TRP #1 and TRP #2 can be associated with the base station. For example, the base station can send an indication of a TRP handover operation to the terminal via signaling. The indication of the TRP handover operation can be sent via either TRP #1 or TRP #2. The terminal can receive the indication of the TRP handover operation from the base station. The base station and / or the terminal can perform a TRP handover operation based on the indication of the TRP handover operation. Communication between the base station and the terminal can be performed via the handover TRP (e.g., TRP #2).

[0164] When a Type 1 TRP handover operation is configured at the terminal and / or base station, communication between the base station and the terminal can be performed via the handover-connected TRP (e.g., TRP #2) until an additional indication is received. The base station can send a UTCI deactivation indication to the terminal. The terminal can receive the UTCI deactivation indication from the base station. The terminal's TCI state can be updated (e.g., changed) based on the UTCI activation indication, and the terminal can perform communication based on the updated TCI state. Even if an indication to release the TCI handover operation (e.g., configuration) is not sent to the terminal, the terminal can still perform communication based on the updated TCI state. Therefore, communication based on the TCI handover operation indication can be terminated. In other words, the TCI handover operation can be initialized. After sending and receiving the UTCI deactivation indication, communication between the base station and the terminal can be performed via the previous TRPs (e.g., TRP #1 and TRP #2).

[0165] Even when a TCI state configuration exists for a TRP, a TRP can be switched (e.g., changed). For example, one TRP can be switched to another. In this case, the base station and / or terminal can expect to perform sTRP communication. The update of the TCI state can be performed based on at least one of an activation command (e.g., activating MAC CE), a deactivation command (e.g., deactivating MAC CE), or a TCI indication (e.g., a TCI field included in the DCI).

[0166] In another approach, an update to the TCI state does not trigger a TRP handover operation. In other words, even when the TCI state is updated, communication between the base station and the terminal can still be performed via the new TRP. Regardless of whether the TCI state is updated, the terminal can perform communication based on the previous TRP handover instruction until it receives an additional TRP handover instruction. The previous TRP handover operation is not initialized until an additional TRP handover instruction is received.

[0167] TCI status updates can be applied to TRPs that have not been switched over. For example, when communication based on TRP #1 and TRP #2 is switched to communication based on TRP #2 according to a TRP handover operation, the TCI status update can be applied to TRP #2. The TCI status update will not be applied to TRP #1.

[0168] - Type 2 of TRP switching operation

[0169] The base station can send an indication of a TRP handover operation (e.g., a trigger command) and information about the TRP handover duration to the terminal. The indication of the TRP handover operation and / or information about the TRP handover duration can be sent to the terminal via signaling (e.g., RRC signaling, MAC signaling, and / or PHY signaling). The terminal can receive the indication of the TRP handover operation and information about the TRP handover duration from the base station. The base station and / or the terminal can perform a TRP handover operation based on the indication of the TRP handover operation. During the TRP handover duration, the base station and / or the terminal can perform communication based on the handed-over TRP (e.g., sTRP or mTRP).

[0170] The TRP handover duration may begin at the reception end time indicated by the TRP handover operation (e.g., the reception end symbol), or after a time interval following the reception end time of the TRP handover gap. Alternatively, the TRP handover duration may begin at the start symbol, any symbol, or the last symbol within the time slot (or subframe) where the TRP handover operation is indicated, or after the time interval following the start symbol, any symbol, or the last symbol of the TRP handover gap.

[0171] In Type 2 TRP handover operations, deactivation signaling operations for the TRP handover operation are not required. Type 2 TRP handover operations can be used when the channel (e.g., channel state) can be predicted (e.g., estimated). The indication of the TRP handover operation and information about the TRP handover duration can be sent via the same signaling message. Alternatively, the indication of the TRP handover operation and information about the TRP handover duration can be sent via different signaling messages. Information about the TRP handover duration can be included in system information and / or RRC messages. The TRP handover duration can be configured in units of symbols, time slots, or time (e.g., ms).

[0172] The base station and / or terminal may perform communication based on the post-handover TRP during the TRP handover duration, and may perform communication based on the pre-handover TRP after the end of the TRP handover duration. For example, the base station and / or terminal may perform mTRP communication during the TRP handover duration and sTRP communication after the end of the TRP handover duration. Alternatively, the base station and / or terminal may perform sTRP communication during the TRP handover duration and mTRP communication after the end of the TRP handover duration.

[0173] Figure 11 This is a timing diagram illustrating an exemplary embodiment of a Type 2 communication method based on TRP switching operations.

[0174] like Figure 11 As shown, the base station can send a UTCI activation indication to the terminal, and the terminal can receive the UTCI activation indication from the base station. Communication between the base station and the terminal can be performed based on the activated UTCI. For example, the terminal can perform communication via TRP #1 and TRP #2. In other words, the terminal can perform mTRP communication. TRP #1 and TRP #2 can be associated with the base station. The base station can send an indication of a TRP handover operation and information about the TRP handover duration to the terminal via signaling. The indication of a TRP handover operation and information about the TRP handover duration can be sent via either TRP #1 or TRP #2. The terminal can receive the indication of a TRP handover operation and information about the TRP handover duration from the base station. The base station and / or the terminal can perform a TRP handover operation based on the indication of the TRP handover operation. Communication between the base station and the terminal can be performed via the handover-connected TRP (e.g., TRP #2). Communication based on TRP (e.g., TRP #2) can be performed during the TRP handover duration.

[0175] After the TRP handover duration ends, the base station and / or terminal can perform communication based on the TRP before the handover (e.g., TRP #1 and TRP #2). In other words, the base station and / or terminal can perform mTRP communication after the TRP handover duration ends. After the TRP handover duration ends, the TCI state of the mTRP before the TRP handover can be applied to mTRP communication.

[0176] The base station can send a UTCI deactivation indication to the terminal. The UTCI deactivation indication can be sent after the TRP handover duration has ended. The terminal can receive the UTCI deactivation indication from the base station. When a TCI state update indication (e.g., a UTCI activation indication or a UTCI deactivation indication) is received, the terminal can change the TCI state based on the updated indication. The terminal can perform mTRP communication based on the changed TCI state. When the TCI state update indication indicates an update to a single TCI state (e.g., when the TCI state update indication indicates a code point for a single TCI state), the terminal can update the TCI state of one of the mTRPs (e.g., two TRPs) and can maintain the TCI state of the remaining TRPs in the mTRP. In other words, the TCI state of the remaining TRPs in the mTRP will not be updated. In this case, the terminal can expect to perform mTRP communication.

[0177] - Type 3 of TRP switching operations

[0178] The base station can send an indication of a TRP handover operation (e.g., a trigger command) and repetition configuration information to the terminal. The repetition configuration information may include at least one of the following: information about the repetition duration of the TRP handover operation, information about the repetition period of the TRP handover operation, and / or information about the number of repetitions of the TRP handover operation. The repetition duration of the TRP handover operation may correspond to the TRP handover duration in Type 1 of the TRP handover operation. The indication of the TRP handover operation and / or the repetition configuration information can be sent to the terminal via signaling (e.g., RRC signaling, MAC signaling, and / or PHY signaling). The terminal can receive the indication of the TRP handover operation and the repetition configuration information from the base station. The base station and / or the terminal can perform the TRP handover operation based on the indication of the TRP handover operation. The handed-over TRP (e.g., sTRP or mTRP) can be maintained during the repetition duration. For example, communication based on the handed-over TRP can be maintained during the repetition duration. The TRP handover operation can be performed according to the repetition period. The TRP handover operation can be performed the same number of times as the number of repetitions.

[0179] When the channel (e.g., channel state) can be predicted (e.g., estimated), TRP handover operation type 3 can be used. According to TRP handover operation type 3, the signaling overhead used for TRP handover operations can be reduced. Each of the repetition duration and repetition period of the TRP handover operation can be configured in units of symbols, time slots, or time (e.g., ms). The number of repetitions of the TRP handover operation can be configured to be at least n. n can be a natural number.

[0180] The repetition duration can be configured based on the repetition period. The repetition duration can be configured to the same number of repetitions. A TRP switching operation can be performed for each repetition duration. For example, a TRP switching operation can be performed at the start time of each repetition duration. The TRP switching operation can be initialized after the end time of the repetition duration. In other words, communication based on the TRP before the switch can be performed after the end time of the repetition duration. Communication based on the TRP before the switch can be performed during the duration from the end time of the repetition duration to the start time of the next repetition duration.

[0181] The base station can send a TCI status update indication to the terminal. It can receive the TCI status update indication before the end of the repeat duration. In this case, the TRP handover operation can be initiated even before the end of the repeat duration. In other words, the repeat duration can be terminated early upon receiving the TCI status update indication.

[0182] In another approach, when an update indication of the TCI state is received before the end of the repetition duration, the update indication can be applied to the TRP that has not been switched over, and not to the TRP that has been switched over. In the above scenario, the terminal can expect to perform mTRP communication. For example, in Figure 11 In an exemplary embodiment, when the TRP switching duration corresponds to the repetition duration, the TCI state update indication can be applied to TRP #2 but not to TRP #1.

[0183] ● Operations of the base station and / or terminal during TCI state update after a TRP handover operation

[0184] The base station can send an indication of a TRP handover operation according to type 1, type 2, or type 3 to the terminal. The terminal can receive the TRP handover operation indication from the base station and perform a TRP handover operation based on the indication. The base station and / or the terminal can perform communication based on the handed-over TRP. After performing the TRP handover operation, the base station can send a TCI status update indication to the terminal. The terminal can receive the TCI status update indication from the receiving station.

[0185] The update indication of TCI status can refer to the configuration of the TCI state pool, the activation of the TCI state pool, and / or the indication of the TCI status. The configuration of the TCI state pool can be based on RRC signaling. The activation of the TCI state pool can be based on MAC CE. The indication of the TCI status can be based on MAC CE and / or DCI. The indication of the TCI status can be an indication of a single TCI status or an indication of a TCI state set. A TCI state set can be a TCI state set for a single type.

[0186] After performing a TRP handover operation, the terminal can receive an update indication of the TCI status from the base station. In this case, the terminal and / or the base station can operate as follows.

[0187] When a terminal receives an indication of a TRP handover operation of type 2 or type 3, it can expect the type of the TRP handover operation to change from type 2 or type 3 to type 1 until it receives an indication of an additional TRP handover operation. When a TRP handover operation indication is received via the DCI, the terminal can reconfigure the beam (e.g., transmit beam and / or receive beam) based on the TCI state associated with the code point indicated by the fields included in the DCI (e.g., the TCI field).

[0188] However, since the higher-layer signaling design for the mTRP TCI state configuration is incomplete, the terminal can reconfigure the TCI state according to the TCI state indication as follows. The base station can configure the terminal with up to the maximum number of TRPs supported by the terminal. This method can be referred to as Method #1. The base station can consider signaling overhead to send signaling information about the changed TCI state to the terminal. This method can be referred to as Method #2. In Method #2, the changed TCI state information can be notified via signaling in a variable manner.

[0189] For example, a separate type can be configured for 4 TRPs, and the TCI states of TRP #2 and TRP #3 can be changed. 4 TRPs can refer to four TRPs. In the above case, according to method #1, the TCI state information (e.g., TCI state configuration) notified by the base station to the terminal via signaling can be [(-, -), (TCI #3, TCI #2), (TCI #5, TCI #4), (-, -)]. "-" can indicate zero-padding or a meaningless value. In the above case, according to method #2, the TCI state information (e.g., TCI state configuration) notified by the base station to the terminal via signaling can be [(TCI #3, TCI #2), (TCI #5, TCI #4)]. Among the TCI states of the TCI codewords within [(-, -), (TCI #3, TCI #2), (TCI #5, TCI #4), (-, -)], the TCI state with the smallest index can be (-, -). Among the TCI states of the TCI codewords in [(TCI #3, TCI #2), (TCI #5, TCI #4)], the TCI state with the smallest index can be (TCI #3, TCI #2).

[0190] A configuration of N TRPs can exist within M TRPs. M TRPs can refer to M TRPs. N TRPs can refer to N TRPs. Both M and N can be natural numbers greater than or equal to 1. M can be greater than N. The TCI states for the M TRPs can be updated according to the TCI codewords, in the order of the lowest or highest index among the TCI states. The terminal can expect the TCI states of (MN) TRPs (e.g., unmapped (MN) TRPs) to remain in the TCI states before the TCI state update. For example, when the terminal is indicated with a federation type, a TRP handover operation to sTRP is indicated (e.g., TCI#5), and the base station TCI state update indication is (TCI#3, TCI#2), the terminal can perform a TCI state update "TCI#5→TCI#3".

[0191] In another example, when a separate type is indicated to the terminal, indicating a TRP handover operation to the sTRP (e.g., TCI #5), and the base station's TCI state update indication is [(TCI #2, TCI #1), (TCI #4, TCI #3)], the terminal can perform a TCI state update "TCI #5 → TCI #2" for DL ​​and "TCI #5 → TCI #1" for UL. The terminal can ignore (TCI #4, TCI #3) as the TCI state update indication.

[0192] In another example, when the terminal is indicated with a federation type, a TRP handover operation to a 2 TRP is indicated (e.g., [(TCI #2), (TCI #3)]), and the base station's TCI state update indication is (TCI #4), the terminal can perform a TCI state update "TCI #2 → TCI #4", and the terminal can maintain TCI #3. In this case, the terminal can expect to perform 2 TRP communication based on [(TCI #4), (TCI #3)].

[0193] ● Adjust TRP switching operation according to beam application time

[0194] The indication of the unified TCI status (e.g., unified TCI status information) can be sent to the terminal via DCI or MAC CE. In this case, the terminal can update the indicated TCI (e.g., the configured TCI) after the beam application time. For the unified TCI framework, a TRP handover operation can be introduced. When the indication of the TRP handover operation occurs before the beam application time, the terminal and / or base station can expect the TRP handover operation to be performed after the beam application time. In other words, the start time of the TRP handover operation can be delayed until after the beam application time.

[0195] When a TRP handover operation begins before the beam application time, the terminal can perform the TRP handover operation without updating the TCI state. The terminal can reconfigure the TCI state after the beam application time. In this case, the number of TRPs used for communication between the terminal and the base station can be based on the TRP handover operation indication. For example, even when the TCI state indication includes the mTRP, when performing a TRP handover operation from mTRP to sTRP before the beam application time, the terminal can update the TCI state with the lowest index according to the TCI codeword and perform sTRP communication based on the updated TCI state. Unlike the above operations, after the beam application time, the TRP handover operation and / or TCI update operation can be performed based on the TCI state indication.

[0196] According to exemplary embodiments of this disclosure, a base station and / or terminal can perform a TRP handover operation based on an indication of a TRP handover operation, and can perform communication via mTRP or sTRP. Exemplary embodiments of this disclosure can be applied to a unified TCI framework and / or a general TCI framework. Exemplary embodiments of this disclosure can be applied to mTRP dynamic handover and / or sTRP dynamic handover. Exemplary embodiments of this disclosure can be applied to licensed frequency bands and / or unlicensed frequency bands.

[0197] The exemplary embodiments of this disclosure can be applied not only to mTRP communication based on a single DCI, but also to mTRP communication based on multiple DCIs. In this disclosure, TRPs can be distinguished by the TCI state indicated (e.g., configured) to the terminal. In other words, the terminal can implicitly distinguish TRPs based on the TCI state. A TRP change can be considered equivalent to a change in the TCI state.

[0198] The panel switching operation, antenna element (AE) switching operation, and / or AE group switching operation of the terminal can be performed in the same or similar manner as the exemplary embodiments of this disclosure (e.g., TRP switching operation). In other words, the exemplary embodiments of this disclosure can be applied to the panel switching operation, AE switching operation, and / or AE group switching operation of the terminal.

[0199] The operation of the method according to exemplary embodiments of this disclosure can be implemented as a computer-readable program or code in a computer-readable recording medium. The computer-readable recording medium can include all kinds of recording devices for storing data that can be read by a computer system. Furthermore, the computer-readable recording medium can store and execute programs or code that can be distributed across computer systems connected via a network and read by a computer in a distributed manner.

[0200] Computer-readable recording media may include hardware devices specifically configured to store and execute program commands, such as ROM, RAM, or flash memory. Program commands may include not only machine language code created by a compiler, but also high-level language code that can be executed by a computer using an interpreter.

[0201] Although some aspects of this disclosure have been described in the context of apparatus, these aspects may indicate a corresponding description according to the method, and blocks or apparatus may correspond to method steps or step features. Similarly, aspects described in the context of the method may be represented as features of corresponding blocks or items or corresponding apparatus. Some or all of the steps of the method may be performed by (or using) hardware means such as microprocessors, programmable computers, or electronic circuits. In some embodiments, one or more of the most important steps of the method may be performed by such means.

[0202] In some exemplary embodiments, programmable logic devices, such as field-programmable gate arrays (FPGAs), can be used to perform some or all of the functions of the methods described herein. In some exemplary embodiments, a microprocessor can operate the FPGA to perform one of the methods described herein. Generally, it is preferred to perform the methods via a hardware device.

[0203] The description in this disclosure is merely exemplary in nature, and therefore, changes that do not depart from the substance of this disclosure are intended to fall within its scope. Such changes should not be considered as departing from the spirit and scope of this disclosure. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope defined by the following claims.

Claims

1. A method for a user equipment (UE), comprising the following steps: It performs first transmit-receive point (TRP) communication with the base station; Receive a first indication of a TRP handover operation from the base station; Based on the first indication, determine the application time of the TRP switching operation; During the application time, a TRP switching operation is performed from the first TRP communication to the second TRP communication; as well as Perform the second TRP communication with the base station. Specifically, when the first TRP communication is a multi-TRP (mTRP) communication, the second TRP communication is a single-TRP (sTRP) communication, and when the first TRP communication is an sTRP communication, the second TRP communication is an mTRP communication.

2. The method according to claim 1, further comprising the following step: Receive information about the TRP handover gap from the base station. The application time is after the TRP switching gap starting from the first indicated reception time.

3. The method according to claim 1, wherein, The application time is after the UE sends its response to the first indication to the base station.

4. The method according to claim 1, wherein, The second TRP communication is performed after the TRP handover operation is executed until the second indication of the TRP handover operation or the Transmission Configuration Indication (TCI) status update indication is received.

5. The method according to claim 1, further comprising the following step: Receive information about the TRP handover duration from the base station. The second TRP communication following the TRP handover operation is performed during the TRP handover duration.

6. The method according to claim 1, further comprising the following step: Receive repeat configuration information for TRP handover operation from the base station. The second TRP communication following the TRP switching operation is performed during the repetition duration indicated by the repetition configuration information.

7. The method according to claim 1, further comprising the following step: Receive TCI status update indication from the base station; as well as To perform the second TRP communication, one or more TRPs update the TCI state. Among the multiple TRPs performing the first TRP communication, the TCI status of the remaining TRPs other than the one or more TRPs mentioned above is not updated.

8. The method according to claim 1, further comprising the following step: Receive TCI status information from the base station The application time is after the beam application time of the TCI status information.

9. A method for using a base station, comprising the following steps: Perform first transmit-receive point (TRP) communication with user equipment (UE); Send the first instruction for the TRP handover operation to the UE; Based on the first indication, determine the application time of the TRP switching operation; During the application time, a TRP switching operation is performed from the first TRP communication to the second TRP communication; as well as Perform the second TRP communication with the UE. Specifically, when the first TRP communication is a multi-TRP (mTRP) communication, the second TRP communication is a single-TRP (sTRP) communication, and when the first TRP communication is an sTRP communication, the second TRP communication is an mTRP communication.

10. The method of claim 9, further comprising the step of: Information about the TRP handover gap is sent to the UE. The application time is after the TRP switching gap starting from the first indicated reception time.

11. The method according to claim 9, wherein, The application time is after the base station receives a response to the first indication from the UE.

12. The method according to claim 9, wherein, The second TRP communication is performed after the TRP handover operation is executed until the second indication of the TRP handover operation or the Transmission Configuration Indication (TCI) status update indication is received.

13. The method of claim 9, further comprising the step of: Information regarding the TRP handover duration is sent to the UE. The second TRP communication following the TRP handover operation is performed during the TRP handover duration.

14. The method of claim 9, further comprising the step of: The repeated configuration information used for TRP handover operations is sent to the UE. The second TRP communication following the TRP switching operation is performed during the repetition duration indicated by the repetition configuration information.

15. The method of claim 9, further comprising the step of: Send TCI status information to the UE. The application time is after the beam application time of the TCI status information.

16. A user equipment (UE) comprising at least one processor, wherein, The at least one processor causes the UE to perform the following operations: It performs first transmit-receive point (TRP) communication with the base station; Receive a first indication of a TRP handover operation from the base station; Based on the first indication, determine the application time of the TRP switching operation; During the application time, a TRP switching operation is performed from the first TRP communication to the second TRP communication; as well as Perform the second TRP communication with the base station. Specifically, when the first TRP communication is a multi-TRP (mTRP) communication, the second TRP communication is a single-TRP (sTRP) communication, and when the first TRP communication is an sTRP communication, the second TRP communication is an mTRP communication.

17. The UE according to claim 16, wherein, The at least one processor also causes the UE to perform the following operations: Receive information about the TRP handover gap from the base station. The application time is after the TRP switching gap starting from the first indicated reception time.

18. The UE according to claim 16, wherein, The second TRP communication is performed after the TRP handover operation is executed until the second indication of the TRP handover operation or the Transmission Configuration Indication (TCI) status update indication is received.

19. The UE according to claim 16, wherein, The at least one processor also causes the UE to perform the following operations: Receive information about the TRP handover duration from the base station. The second TRP communication following the TRP handover operation is performed during the TRP handover duration.

20. The UE according to claim 16, wherein, The at least one processor also causes the UE to perform the following operations: Receive repeat configuration information for TRP handover operation from the base station. The second TRP communication following the TRP switching operation is performed during the repetition duration indicated by the repetition configuration information.

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