WO2025033764A1 - Method and device for transmitting and receiving data channels in multi-trp system - Google Patents

Abstract

Disclosed are a method and device for transmitting and receiving data channels in a multi-TRP system. The method performed by a UE comprises the steps of: receiving DCI of a base station via a first TRP or a second TRP; determining a scheduling offset, between the DCI and a PDSCH occasion scheduled by the DCI, on the basis of PDSCH scheduling information included in the DCI; determining one or more TCI states for one or more PDSCH receptions on the basis of the result of comparing the scheduling offset and a time duration; and receiving one or more PDSCHs of the base station via at least one of the first TRP or the second TRP on the basis of the one or more TCI states.

Description

Method and device for transmitting and receiving data channels in a multi-TRP system

The present disclosure relates to improved communication technology, and more particularly, to a technology for transmitting and receiving data channels in a communication system supporting multiple transmission and reception points (TRPs).

Communication networks (e.g., 5G communication networks, 6G communication networks, etc.) are being developed to provide improved communication services compared to existing communication networks (e.g., LTE (long term evolution), LTE-A (advanced), etc.). A 5G communication network (e.g., NR (new radio) communication network) can support not only a frequency band below 6 GHz but also a frequency band above 6 GHz. That is, the 5G communication network can support FR1 band and/or FR2 band. A 5G communication network can support various communication services and scenarios compared to an LTE communication network. For example, usage scenarios of a 5G communication network can include eMBB (enhanced Mobile BroadBand), URLLC (Ultra Reliable Low Latency Communication), mMTC (massive Machine Type Communication), etc.

6G communication networks can support various communication services and scenarios compared to 5G communication networks. 6G communication networks can satisfy requirements of ultra-performance, ultra-bandwidth, ultra-space, ultra-precision, ultra-intelligence, and/or ultra-reliability. 6G communication networks can support various and wide frequency bands and can be applied to various usage scenarios (e.g., terrestrial communication, non-terrestrial communication, sidelink communication, etc.).

Meanwhile, mTRP (multiple transmission and reception point) can be introduced into a communication network (e.g., 5G communication network and/or 6G communication network). mTRP can be located geographically apart. A base station can communicate with a terminal using mTRP. mTRP technology can be used to solve QoS (quality of service) reduction problem of cell-edge terminal and/or inter-cell interference problem. mTRP technology can be used to provide an additional communication path in an environment where NLOS (non line-of-sight) path is limited.

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

A communication system may support a unified transmission configuration indicator (TCI). In a communication system supporting the unified TCI, a reception operation of a physical downlink shared channel (PDSCH) may be performed as follows. A terminal may receive downlink control information (DCI) and check indication information of TCI state(s) included in the DCI. The terminal may expect PDSCH reception by applying the TCI state(s) indicated (e.g., set) by the DCI after a certain time period (e.g., beam application time (BAT)). Meanwhile, capabilities may vary depending on the terminal, and the time required to apply the TCI state may vary depending on the terminal capability. Methods for PDSCH reception that consider the terminal capability (e.g., the time required to apply the TCI state) may be necessary.

The purpose of the present disclosure to solve the above problems is to provide a method and device for transmitting and receiving a data channel in a communication system supporting multiple transmission and reception points (TRPs).

According to embodiments of the present disclosure for achieving the above object, a method of a UE includes the steps of receiving a DCI of a base station through a first TRP or a second TRP, determining a scheduling offset between the DCI and a PDSCH occasion scheduled by the DCI based on PDSCH scheduling information included in the DCI, determining one or more TCI states for one or more PDSCH receptions based on a comparison result between the scheduling offset and a time duration, and receiving one or more PDSCHs of the base station through at least one of the first TRP or the second TRP based on the one or more TCI states.

If the UE does not support two default beams, the one or more TCI states may be determined based on the comparison result between the scheduling offset and the time duration, and if the UE supports two default beams, the one or more TCI states may be determined regardless of the comparison result between the scheduling offset and the time duration.

If the end time of the scheduling offset is before the end time of the time duration, the one or more TCI states for the one or more PDSCH receptions may be determined as the first indicated TCI state set for the UE.

"If the end time of the scheduling offset is after the end time of the time duration and the format of the DCI is DCI format 1_0", the one or more TCI states for the one or more PDSCH receptions may be determined as one or more TCI states indicated by signaling of the base station.

"If the end time of the scheduling offset is after the end time of the time duration, the format of the DCI is DCI format 1_0, and the one or more TCI states are not indicated by signaling of the base station," the one or more TCI states for the one or more PDSCH receptions may be determined as a first indicated TCI state set in the UE.

"If an end time of the scheduling offset is after an end time of the time duration, and a format of the DCI is DCI format 1_1 or DCI format 1_2, and the DCI format 1_1 or the DCI format 1_2 does not include a TCI selection field," the one or more TCI states for the one or more PDSCH receptions can be determined as a first indicated TCI state and a second indicated TCI state set for the UE.

"If an end time of the scheduling offset is after an end time of the time duration, and a format of the DCI is DCI format 1_1 or DCI format 1_2, and the DCI format 1_1 or the DCI format 1_2 includes a TCI selection field," the one or more TCI states for the one or more PDSCH receptions can be determined based on a value of a codepoint of the TCI selection field.

The method of the UE may further include the step of determining the time duration indicating the application time of the TCI state, and the step of transmitting information about the time duration to the base station via at least one of the first TRP or the second TRP, wherein the time duration may include a correction time additionally required for beam setting for the one or more PDSCHs having different numerologies.

The time duration may be determined based on the sum of a time required for reception of the DCI and a time required for preparation for reception of the one or more PDSCHs based on the DCI, and a start time of the time duration may be a start time or an end time of the DCI, and the start time of the time duration may be preset by at least one of the UE or the base station.

The start time of the scheduling offset may be the start time or the end time of the DCI, the end time of the scheduling offset may be the start time or the end time of the PDSCH occasion, and each of the start time and the end time of the scheduling offset may be preset by at least one of the UE or the base station.

According to embodiments of the present disclosure for achieving the above object, a method of a UE comprises: the UE including at least one processor, the at least one processor causing the UE to receive a DCI of a base station through a first TRP or a second TRP, determine a scheduling offset between the DCI and a PDSCH occasion scheduled by the DCI based on PDSCH scheduling information included in the DCI, determine one or more TCI states for one or more PDSCH receptions based on a comparison result between the scheduling offset and a time duration, and receive one or more PDSCHs of the base station through at least one of the first TRP or the second TRP based on the one or more TCI states.

If the UE does not support two default beams, the one or more TCI states may be determined based on the comparison result between the scheduling offset and the time duration, and if the UE supports two default beams, the one or more TCI states may be determined regardless of the comparison result between the scheduling offset and the time duration.

If the end time of the scheduling offset is before the end time of the time duration, the one or more TCI states for the one or more PDSCH receptions may be determined as the first indicated TCI state set for the UE.

"If the end time of the scheduling offset is after the end time of the time duration and the format of the DCI is DCI format 1_0", the one or more TCI states for the one or more PDSCH receptions may be determined as one or more TCI states indicated by signaling of the base station.

"If the end time of the scheduling offset is after the end time of the time duration, the format of the DCI is DCI format 1_0, and the one or more TCI states are not indicated by signaling of the base station," the one or more TCI states for the one or more PDSCH receptions may be determined as a first indicated TCI state set in the UE.

"If an end time of the scheduling offset is after an end time of the time duration, and a format of the DCI is DCI format 1_1 or DCI format 1_2, and the DCI format 1_1 or the DCI format 1_2 does not include a TCI selection field," the one or more TCI states for the one or more PDSCH receptions can be determined as a first indicated TCI state and a second indicated TCI state set for the UE.

"If an end time of the scheduling offset is after an end time of the time duration, and a format of the DCI is DCI format 1_1 or DCI format 1_2, and the DCI format 1_1 or the DCI format 1_2 includes a TCI selection field," the one or more TCI states for the one or more PDSCH receptions can be determined based on a value of a codepoint of the TCI selection field.

The at least one processor may further cause the UE to determine the time duration indicating the application time of the TCI state; and transmit information about the time duration to the base station via at least one of the first TRP or the second TRP, wherein the time duration may include a correction time additionally required for beam setting for the one or more PDSCHs having different numerologies.

The time duration may be determined based on the sum of a time required for reception of the DCI and a time required for preparation for reception of the one or more PDSCHs based on the DCI, and a start time of the time duration may be a start time or an end time of the DCI, and the start time of the time duration may be preset by at least one of the UE or the base station.

The start time of the scheduling offset may be the start time or the end time of the DCI, the end time of the scheduling offset may be the start time or the end time of the PDSCH occasion, and each of the start time and the end time of the scheduling offset may be preset by at least one of the UE or the base station.

According to the present disclosure, in a PDSCH (physical downlink shared channel) reception procedure of mTRP (multiple transmission and reception point) communication based on a single DCI (downlink control information), a beam for PDSCH reception before a time at which a transmission configuration indicator (TCI) state is updated (e.g., a beam application time (BAT)) can be dynamically indicated/configured. Depending on a gap between a physical downlink control channel (PDCCH) and a PDSCH scheduled by the PDCCH and a minimum required time for beam application, the TCI state(s) of a terminal for PDSCH reception can vary. A start position and/or an end position of the gap between the PDCCH and the scheduled PDSCH can be clearly defined, and a start position of the minimum required time can be clearly defined. Based on the above definitions, ambiguity in beam configuration for the PDSCH at the terminal and the base station can be resolved.

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

FIG. 2 is a block diagram illustrating embodiments of communication nodes constituting a communication system.

Figure 3 is a block diagram illustrating embodiments of communication nodes performing communication.

FIG. 4a is a block diagram illustrating embodiments of transmission paths.

FIG. 4b is a block diagram illustrating embodiments of a receiving path.

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

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

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

Figure 8 is a conceptual diagram illustrating examples of time-frequency resources in a communication system.

FIG. 9 is a conceptual diagram illustrating a method for receiving PDSCH(s) based on the support capability of default beams in mTRP communication based on a single DCI.

Figure 10 is a conceptual diagram illustrating methods for receiving PDSCHs based on different reference points.

Figure 11 is a flowchart illustrating a method of transmitting and receiving a data channel in a single DCI-based mTRP communication.

The present disclosure may have various modifications and various embodiments, and thus specific embodiments are illustrated and described in detail in the drawings. However, this is not intended to limit the present disclosure to specific embodiments, but should be understood to include all modifications, equivalents, and alternatives included in the spirit and technical scope of the present disclosure.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are only used to distinguish one component from another. For example, without departing from the scope of the present disclosure, the first component could be referred to as the second component, and similarly, the second component could also be referred to as the first component. The term "and/or" can mean a combination of a plurality of related listed items or any one of a plurality of related listed items.

In the present disclosure, "at least one of A and B" can mean "at least one of A or B" or "at least one of combinations of one or more of A and B." Additionally, in the present disclosure, "at least one of A and B" can mean "at least one of A or B" or "at least one of combinations of one or more of A and B."

In the present disclosure, (re)transmitting can mean “transmitting”, “retransmitting”, or “transmitting and retransmitting”, (re)setting can mean “setting”, “resetting”, or “setting and resetting”, (re)connecting can mean “connecting”, “reconnecting”, or “connecting and reconnecting”, and (re)connecting can mean “connecting”, “reconnecting”, or “connecting and reconnecting”.

When it is said that a component is "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components in between. On the other hand, when it is said that a component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

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

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless expressly defined in this disclosure.

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

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

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

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

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

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

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

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

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

FIG. 2 is a block diagram illustrating embodiments of communication nodes constituting a communication system.

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

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

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

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

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

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

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

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

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

Figure 3 is a block diagram illustrating embodiments of communication nodes performing communication.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Referring to FIG. 7, one slot may include one or more symbols. One slot illustrated in FIG. 7 may include 14 symbols. The length of a slot may vary depending on the number of symbols included in the slot and the length of the symbols. Alternatively, the length of a slot may vary depending on the numerology.

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

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

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

A symbol may be configured as a downlink (DL) symbol, a flexible (FL) symbol, or an uplink (UL) symbol. A slot composed of only DL symbols may be referred to as a "DL slot," a slot composed of only FL symbols may be referred to as a "FL slot," and a slot composed of only UL symbols may be referred to as a "UL slot."

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

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

Figure 8 is a conceptual diagram illustrating examples of time-frequency resources in a communication system.

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

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

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

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

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

The search space information may include a CORESET ID (identifier) associated with the search space, a period of PDCCH monitoring, and/or an offset. Each of the period and offset of PDCCH monitoring may be indicated in slot units. In addition, the search space information may further include an index of a symbol at which a PDCCH monitoring operation starts.

A base station can set a BWP (bandwidth part) for downlink communication. The BWP can be set differently for each terminal. The base station can inform the terminal of the configuration information of the BWP using upper layer signaling. The upper layer signaling can mean "transmission operation of system information" and/or "transmission operation of RRC (radio resource control) message." The number of BWPs set for one terminal can be 1 or more. The terminal can receive configuration information of the BWP from the base station, and can identify the BWP(s) set by the base station based on the configuration information of the BWP. When a plurality of BWPs are set for downlink communication, the base station can activate one or more BWPs among the plurality of BWPs. The base station can transmit the configuration information of the activated BWP(s) to the terminal using at least one of upper layer signaling, MAC (medium access control) CE (control element), or DCI. The base station can perform downlink communication using the activated BWP(s). The terminal can identify the activated BWP(s) by receiving configuration information of the activated BWP(s) from the base station, and perform a downlink reception operation in the activated BWP(s).

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

The mTRP technology may fall into the category of MIMO technology. The mTRP may have characteristics (e.g., level characteristics) of a macro cell, a small cell, a pico cell, and/or a femto cell. The mTRP may perform data transmission for one terminal. When a channel (e.g., a link) with an uneven channel environment exists due to obstacles and/or interference, the mTRP may attenuate the effects of the obstacles and/or interference. The mTRP may improve a data transmission rate for terminals located at a cell edge area.

Communication based on mTRP can be performed based on the coherent joint transmission (CJT) scheme or the non-CJT (NCJT) scheme. In the CJT scheme, the base station can know the channel information between each mTRP and the terminal, and can perform a preprocessing operation on the data based on the channel information. In this case, the overhead due to the transmission procedure of the channel information may increase, and the problem of synchronization constraints between the TRPs may occur. In the NCJT scheme, the base station may not need to know the channel information between each mTRP and the terminal. The mTRP can transmit data to the terminal without performing a preprocessing operation such as phase compensation. The complexity of the NCJT scheme may be lower than that of the CJT scheme.

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

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

In the multi-DCI scheme, scheduling of PDSCH for each TRP can be performed by an individual DCI. PDSCHs scheduled by multiple DCIs can be fully overlapped or partially overlapped. Alternatively, PDSCHs scheduled by multiple DCIs can be non-overlapping. In both the single DCI scheme and the multi-DCI scheme, the DCI can include TCI (transmission configuration indicator) state information for the PDSCH.

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

Enhancements (e.g., PDCCH enhancements) can be performed to improve reliability and/or robustness of mTRP communications. Deployment scenarios of PDCCH enhancements can be classified into single frequency network (SFN) and non-SFN.

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

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

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

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

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

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

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

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

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

In a communication system supporting integrated TCI, the reception operation of PDSCH can be performed as follows. The terminal can receive DCI and check the indication information of TCI state(s) included in the DCI. The terminal can expect PDSCH reception by applying the TCI state(s) indicated (e.g., configured) by the DCI after a certain time period (e.g., beam application time (BAT)). Meanwhile, the PDSCH can be transmitted before the BAT. For PDSCH reception before the BAT, a TCI selection field can be introduced. The terminal can expect PDSCH reception before the BAT based on the TCI selection field. In other words, the TCI selection field can dynamically indicate PDSCH reception before the BAT. The TCI selection field can be included in the DCI. Whether the TCI selection field exists in the DCI can be preset by RRC signaling. The terminal can check whether the DCI includes the TCI selection field based on the setting by the RRC signaling.

Regardless of whether a TCI selection field exists in the DCI, a terminal can receive DCI (e.g., PDCCH), decode information included in the DCI, and set a beam for PDSCH reception based on the decoded information. Beam setting may mean determination of a TCI state. The ability to set a beam for PDSCH reception may vary from terminal to terminal. In a PDSCH reception procedure of a single DCI-based mTRP communication, a time (e.g., a minimum time) required for applying a TCI state may vary from terminal to terminal, and thus, a rule for setting a PDSCH reception beam may be required.

FIG. 9 is a conceptual diagram illustrating a method for receiving PDSCH(s) based on the support capability of default beams in mTRP communication based on a single DCI.

Referring to FIG. 9, single DCI based mTRP communication can be performed in FR2 band. In case A, a terminal can support M default beams, and in case B, a terminal may not support the M default beams. M may be 2. Or, M may be 2 or more. The M default beams may be preset in the terminal. The default beam(s) may mean beam(s) used for PDCCH reception. A terminal supporting the M default beams may report the capability of the M default beams (e.g., the M default beams for single DCI based mTRP communication) to a base station. A terminal not supporting the M default beams may be a terminal that has not reported the capability of the M default beams (e.g., the M default beams for single DCI based mTRP communication) to the base station. In Case A, the UE can apply TCI state(s) based on a rule defined for each DCI format regardless of the scheduling offset (e.g., time offset) between the DCI and the PDSCH, and can expect PDSCH reception based on the application of the TCI state(s). "Expectation of PDSCH reception" may be interpreted as "receiving a PDSCH" depending on the context. The default beam may mean a beam of the UE used when TCI configuration information does not exist in the DCI. Alternatively, the default beam may mean a beam of the UE used in a situation where application of the TCI configuration information is impossible. The TCI configuration information may include a TCI field (e.g., a TCI state field), a TCI selection field, TCI-related information set by MAC CE, and/or TCI-related information set by RRC signaling.

In Case B, the operation of the terminal (e.g., the beam setting operation of the terminal) may vary depending on the location of the PDSCH occasion in the time domain. If the PDSCH occasion exists before the end time of the scheduling offset (e.g., the time offset), the terminal may use the first indicated joint/DL TCI state for PDSCH reception from the mTRP. The end time of the scheduling offset may mean the application time of the TCI configuration information. In other words, the end time of the scheduling offset may be BAT. If the PDSCH occasion exists after the end time of the scheduling offset, the terminal may apply the TCI state(s) based on the rule defined for each DCI format, and may expect PDSCH reception (e.g., scheduled PDSCH reception) based on the application of the TCI state(s).

Definition of scheduling offset may be required for application of TCI state(s). For example, definition of start time, end time, and/or duration of scheduling offset may be required. If scheduling offset is not clearly defined, setting (e.g., application) of TCI state(s) may vary depending on a reference point of PDCCH reception and/or a reference point of scheduled/activated PDSCH reception. In other words, if scheduling offset is not clearly defined, ambiguity may arise regarding setting (e.g., application) of TCI state(s). Therefore, setting (e.g., application) of TCI state(s) may vary for each terminal. Whether to apply default beam may be determined depending on the definition of scheduling offset.

In an embodiment of the present disclosure, methods for setting a beam of a terminal for PDSCH reception in a single DCI-based mTRP communication will be described. The methods for setting a beam of a terminal for PDSCH reception in a single DCI-based mTRP communication can be applied to setting a beam of a terminal for PDSCH reception in a multi-DCI-based mTRP communication. The mTRP communication can mean not only two TRP communications but also three or more TRP communications. Unified TCI can be supported in sTRP communications and/or mTRP communications. In the single DCI-based mTRP communication, a base station can set up data transmission from an mTRP to a terminal using a single DCI (e.g., a single PDCCH). The base station can transmit information on a reception beam (e.g., a reception beam of the terminal) for a data channel (e.g., a PDSCH) transmitted in each mTRP to the terminal together with information on decoding of the data channel. In general, TCI state(s) indicated (e.g., set) by DCI can be applied to channels existing after the beam application time (BAT).

If the DCI includes indication information for TCI state(s) (e.g., TCI configuration information) and PDSCH scheduling information, the TCI state(s) indicated by the DCI may be applied to PDSCH reception before BAT. In other words, during the time period from the reception time of the DCI to BAT, the UE can receive the PDSCH based on the TCI state(s) indicated by the DCI. To support the above operation, the DCI format including the PDSCH scheduling information (e.g., DCI format 1_1, DCI format 1_2) may utilize additional bits (e.g., TCI selection field) to dynamically configure a reception beam for the PDSCH.

The time required for decoding of PDCCH and/or the time required for setting up a reception beam for PDSCH based on the decoding result of PDCCH may vary from terminal to terminal. A beam setting operation for a PDSCH existing within (e.g., before) the required time may be different from a beam setting operation for a PDSCH existing outside (e.g., after) the required time. The beam setting operations may be distinguished based on a threshold (e.g., time duration).

In the present disclosure, application of TCI state(s) may mean application of receive beam configuration, transmit beam configuration, and/or application of quasi co-location (QCL) to resources, depending on the context. In other words, application of TCI state(s), receive beam configuration, transmit beam configuration, and/or application of quasi co-location (QCL) to resources may be used interchangeably.

- Proposal method #1: Definition of scheduling offsets (e.g., time offset, timing offset) and/or time duration (e.g., threshold).

In a PDSCH reception procedure of a single DCI-based mTRP communication, a configuration operation for TCI state(s) of a terminal may be different depending on a time period (e.g., gap, scheduling offset) between a PDCCH (e.g., DCI) conveying PDSCH resource information (e.g., PDSCH scheduling information) and TCI configuration information and a PDSCH scheduled by the PDCCH. The time duration (e.g., threshold) may mean "a time (e.g., minimum time) required for a reception operation (e.g., decoding operation) of a PDCCH + a time (e.g., minimum time) required to apply the TCI state(s) indicated by the PDCCH to the scheduled PDSCH reception(s)." The time required to apply the TCI state(s) indicated by the PDCCH to the scheduled PDSCH reception(s) may mean a time required to prepare for reception of the PDSCH(s) based on the PDCCH (e.g., DCI). The time duration can be used for PDSCH reception scheduled by PDCCH separately from other DL channels and/or UL channels.

A terminal supporting M default beams can apply TCI state(s) regardless of time duration. A terminal not supporting M default beams can apply TCI state(s) considering time duration. M can be a natural number greater than or equal to 2. The time duration can be applied to a terminal not supporting M default beams. In other words, the time duration can mean "a time (e.g., a minimum time) required for a reception operation (e.g., a decoding operation) of a PDCCH + a time (e.g., a minimum time) required to apply the TCI state(s) indicated by the PDCCH to scheduled PDSCH reception(s)" in a terminal not supporting M default beams.

The time duration may vary depending on the capability of the terminal. The terminal may transmit information about the time duration to the base station. The base station may receive information about the time duration from the terminal. Information about the time duration may be transmitted in a UE capability reporting procedure. The base station may schedule a PDSCH for the terminal by considering the time duration. The base station may determine a start time and/or an end time of a scheduling offset by considering the time duration for each terminal, and may transmit information about the determined start time and/or the determined end time to the terminal by signaling. The base station may determine a start time of the time duration by considering the time duration for each terminal, and may transmit information about the determined start time to the terminal by signaling. The unit of the time duration may be a symbol, a slot, or a subframe. Since the time required for a decoding operation and/or a beam sweeping operation is within the time corresponding to one slot, the time duration may be reported in units of symbols.

The time duration can be scaled according to the numerology (e.g., subcarrier spacing (SCS)). The terminal can report the time duration per SCS to the base station. In order to reduce the signaling overhead of the time duration, the terminal can report the time duration for a representative SCS to the base station. The base station can receive information about the time duration for the representative SCS from the terminal, and derive (e.g., estimate) the time duration for another SCS based on the time duration for the representative SCS. For example, the base station can derive the time duration for another SCS as an increased or decreased time duration based on the time duration for the representative SCS. The time duration can be proportional or inversely proportional to the SCS.

A UE can receive PDSCHs from an mTRP on component carriers (CCs) having the same numerology (e.g., the same SCS). Alternatively, the UE can receive PDSCHs from an mTRP on CCs having different numerologies. No additional time may be required for beam setup for PDSCH reception having the same PDCCH and the same numerology. A correction time according to a variation of the numerology may be required for beam setup for PDSCHs having different numerologies (e.g., PDSCH receptions). In other words, the correction time may be an additional time required for beam setup for PDSCHs having different numerologies. PDSCHs having different numerologies can be received on aggregated CCs having different numerologies. The correction time may be added to a time duration reported by the UE. A base station may schedule a PDSCH by considering the time duration including the correction time.

- Proposal method #2 : Reference point for time duration and scheduling offset

An interval (e.g., gap) between a PDSCH occasion and a time (e.g., reception time) of a PDCCH scheduling the PDSCH occasion may be defined as an offset (e.g., scheduling offset). A terminal may compare a scheduling offset with a time duration (e.g., a threshold) and apply TCI state(s) based on a result of the comparison. In other words, the operation of the terminal for applying the TCI state(s) may vary depending on the time interval. Ambiguity may occur regarding the length of the scheduling offset (e.g., a start time and/or an end time). If there is no clear reference point for the scheduling offset, a first terminal may determine (e.g., calculate) a scheduling offset based on a start symbol of a PDCCH and compare the determined scheduling offset with a time duration. A second terminal may determine (e.g., calculate) a scheduling offset based on an end symbol of a PDCCH and compare the determined scheduling offset with a time duration. In the absence of a clear reference point for the time duration, the time duration may start from the start symbol or the end symbol of the PDCCH. In this case, ambiguity may arise in the comparison result between the scheduling offset and the time duration.

Figure 10 is a conceptual diagram illustrating methods for receiving PDSCHs based on different reference points.

Referring to FIG. 10, single DCI-based mTRP communication can be performed in the FR2 band. The base station can transmit scheduling DCI (e.g., DCI format 1_x) to the terminal through mTRP. The terminal can receive the scheduling DCI of the base station through mTRP. In DCI 1_x, x can be an integer greater than or equal to 0. In Case C, the time duration (e.g., threshold) can start from a start point (e.g., start position, start symbol) of DCI format 1_x. In Case D, the time duration (e.g., threshold) can start from an end point (e.g., end position, end symbol) of DCI format 1_x.

If the end time of the scheduling offset is before the end time of the time duration (e.g., if the offset is smaller than the time duration), the terminal may apply a first indicated TCI state (e.g., a first indicated joint/DL TCI state) to the scheduled PDSCH (e.g., PDSCH reception). The first indicated joint/DL TCI state may be preset by the base station. The terminal may have two indicated TCI states, and the first indicated TCI state may be one of the two indicated TCI states. In the present disclosure, the indicated TCI state and the indicated joint/DL TCI state may be used interchangeably. For example, the indicated TCI state may be interpreted as the indicated joint/DL TCI state depending on the context, and the indicated joint/DL TCI state may be interpreted as the indicated TCI state depending on the context. The indicated TCI state may be used to encompass the indicated joint/DL TCI state.

If the end time of the scheduling offset is after the end time of the time duration (e.g., if the offset is greater than the time duration), the UE may apply the TCI state(s) based on the RRC configuration to the scheduled PDSCH. In other words, the UE may receive the PDSCH based on the "TCI state(s) indicated by the TCI configuration information included in the DCI" or the "TCI state(s) indicated by the RRC message and/or MAC CE" according to the RRC configuration.

In Case C, a start position of the time duration can be a start position of a PDCCH (e.g., DCI format 1_x), a start position of the scheduling offset in C-1 of Case C can be a start position of a PDCCH (e.g., DCI format 1_x), and a start position of the scheduling offset in C-2 of Case C can be an end position of the PDCCH (e.g., DCI format 1_x). A length of the scheduling offset in C-1 of Case C can be identical to a length of the scheduling offset in C-2 of Case C. In C-1 of Case C, the UE can apply a first indicated joint/DL TCI state for PDSCH reception. In C-2 of Case C, the UE can apply "TCI state(s) indicated by TCI configuration information included in DCI" or "TCI state(s) indicated by RRC message and/or MAC CE" according to an RRC configuration for PDSCH reception. Even if the starting positions of the time durations are the same, different TCI states can be applied if the starting positions of the scheduling offsets are different.

In Case C and Case D, the start positions of the time durations may be different. When the start positions of the time durations are different, the configuration for the reception beam of the PDSCH may be different. In Case C-2 of Case C, since the end point of the scheduling offset is after the end point of the time duration, the UE can apply either "TCI state(s) indicated by the TCI configuration information included in DCI" or "TCI state(s) indicated by the RRC message and/or MAC CE" according to the RRC configuration for PDSCH reception. In Case D-2 of Case D, since the end point of the scheduling offset is before the end point of the time duration, the UE can apply the first indicated joint/DL TCI state for PDSCH reception.

In situations such as Case C and/or Case D, the reception performance of the PDSCH may vary depending on the terminal, and the base station may not be aware of the status of the reception beam setting of the terminal. To solve the above problem, it is necessary to clearly define the start position (e.g., start time) of the scheduling offset and/or the time duration. The start position of the scheduling offset and/or the time duration may be the start symbol (e.g., the first symbol) or the end symbol (e.g., the last symbol) of the PDCCH. Alternatively, the start position of the scheduling offset and/or the time duration may be the start symbol (e.g., the first symbol) or the end symbol (e.g., the last symbol) of the search space (or the CORESET associated with the search space) in which the PDCCH is transmitted.

The start position of the scheduling offset and the start position of the time duration may be set to be the same. In other words, for clear calculation of the scheduling offset and/or simple comparison between the scheduling offset and the time duration, the start position of the scheduling offset and the start position of the time duration may be set to be the same. The end position of the scheduling offset may be the start symbol (e.g., the first symbol) or the end symbol (e.g., the last symbol) of the PDSCH according to the definition of the time duration. If the time duration is defined to include the time required to apply the indicated/configured TCI state(s) to the PDSCH reception, the start symbol of the PDSCH may be regarded as the end position of the scheduling offset.

If the start position of the time duration is not defined, the terminal and/or the base station may consider the start position of the time duration to be the same as the start position of the scheduling offset. If the start position of the scheduling offset is not defined, the terminal and/or the base station may consider the start position of the scheduling offset to be the same as the start position of the time duration. Alternatively, if the start position of the time duration is not defined, the terminal and/or the base station may consider the start position of the time duration to be the start position or the end position of the PDCCH. If the start position of the scheduling offset is not defined, the terminal and/or the base station may consider the start position of the scheduling offset to be the start position or the end position of the PDCCH, and the terminal and/or the base station may consider the end position of the scheduling offset to be the start position or the end position of the PDSCH occasion.

The embodiments of the present disclosure can be applied not only to licensed bands but also to unlicensed bands. The time duration and/or scheduling offset can be set for each panel (e.g., antenna array), and communication through each panel can be performed based on the time duration and/or scheduling offset of the corresponding panel. The terminal can report information on the time duration for each panel to the base station. Alternatively, the terminal can report information on the common time duration for the panels to the base station. The time duration of each panel can be determined based on the common time duration and the specific offset.

Figure 11 is a flowchart illustrating a method of transmitting and receiving a data channel in a single DCI-based mTRP communication.

Referring to FIG. 11, a communication system may include a base station, a first TRP, a second TRP, and a terminal. The communication system may support single DCI-based mTRP communication and/or multi-DCI-based mTRP communication. A TCI state list (e.g., dl-OrJointTCI-StateList ) may be set in the terminal. The TCI state list may be set in the terminal by RRC signaling (e.g., RRC configuration) of the base station. The terminal may have two indicated TCI states. The two indicated TCI states may include a first indicated TCI state and a second indicated TCI state.

The terminal may transmit at least one of "information indicating whether the terminal supports two default beams (e.g., two default beams for single DCI-based mTRP communication)" or "information on time duration" to the base station via the first TRP and/or the second TRP (S1101). The base station may receive at least one of "information indicating whether the terminal supports two default beams" or "information on time duration" from the terminal (S1101). S1101 may be a reporting procedure of UE capability information. The two default beams may be two default beams for single DCI-based mTRP communication. The time duration may mean a time duration for QCL. In other words, the time duration may indicate a BAT (e.g., an application time point of a TCI field and/or a TCI selection field).

The time duration can be set per SCS. For example, the terminal can transmit information about the time duration for SCS 60kHz and/or information about the time duration for SCS 120kHz to the base station. The time duration for SCS 60kHz can be set to 7 symbols, 14 symbols, or 28 symbols. The time duration for SCS 120kHz can be set to 14 symbols or 28 symbols. The time duration can be set to include a correction time. The correction time can be a time required according to a variation of the numerology for beam setting for PDSCH receptions having different numerologies.

The base station may generate DCI (e.g., DCI format 1_x) including PDSCH scheduling information when there is downlink data to be transmitted to the terminal (S1102). The DCI may further include TCI configuration information (e.g., a TCI field and/or a TCI selection field). The base station may generate PDSCH scheduling information considering a time duration received from the terminal. For example, the base station may schedule the PDSCH such that a PDSCH occasion exists after the time duration. The PDSCH scheduling information may include time resource allocation information and/or frequency resource allocation information for the PDSCH occasion. The time duration may be predefined in the base station and/or the terminal as starting from a start position (e.g., a start symbol) or an end position (e.g., an end symbol) of the DCI.

Alternatively, the terminal may determine a start position of the time duration (e.g., a start symbol or an end symbol of the DCI) and transmit information indicating the determined start position of the time duration to the base station. For example, the information indicating the determined start position of the time duration may be transmitted in S1101. Alternatively, the base station may determine a start position of the time duration (e.g., a start symbol or an end symbol of the DCI) and transmit information indicating the determined start position of the time duration to the terminal via signaling (e.g., RRC signaling, MAC signaling, and/or PHY signaling). The information indicating the determined start position of the time duration may be transmitted to the terminal after S1101. The information indicating the determined start position of the time duration may be included in an RRC message, a MAC CE, and/or a DCI transmitted by the base station.

The base station can transmit DCI to the terminal through the first TRP or the second TRP (S1103). In other words, the DCI can be transmitted to the terminal through one TRP. The terminal can receive the DCI of the base station through the first TRP or the second TRP (S1103). The terminal can check information included in the DCI (e.g., PDSCH scheduling information, TCI field, TCI selection field, etc.).

The terminal can check the offset (e.g., scheduling offset) between the reception time of the DCI and the reception time of the PDSCH scheduled by the DCI (e.g., PDSCH occasion) based on the PDSCH scheduling information included in the DCI (S1104). The scheduling offset can be determined based on one of the methods specified in Table 2 below.

The base station can determine one of the schemes 1-1 to 1-4 specified in Table 2, and transmit information indicating that the determined one scheme is used to the terminal through signaling. For example, the information indicating the scheme determined by the base station can be included in an RRC message, a MAC CE, and/or a DCI. The terminal can determine a scheduling offset based on the scheme indicated by the base station. Alternatively, the terminal can determine one of the schemes 1-1 to 1-4 specified in Table 2, and transmit information indicating that the determined one scheme is used to the base station through signaling. The operation of notifying the base station of the determined one scheme can be omitted. The terminal can determine a scheduling offset based on the determined one scheme.

The methods in Table 2 can be set to be associated with information indicating the start point of the time duration. For example, Table 3 can be set.

The base station can determine one of the schemes 2-1 to 2-8 specified in Table 3, and transmit information indicating that the determined scheme is used to the terminal through signaling. For example, the information indicating the scheme determined by the base station can be included in an RRC message, MAC CE, and/or DCI. The terminal can determine a scheduling offset based on the scheme indicated by the base station. Alternatively, the terminal can determine one of the schemes 2-1 to 2-8 specified in Table 3, and transmit information indicating that the determined scheme is used to the base station through signaling. The operation of notifying the base station of the determined scheme can be omitted. The terminal can determine a scheduling offset based on the determined scheme.

In S1105, a terminal (e.g., a terminal that does not support two default beams) may compare the time duration and the scheduling offset, and determine TCI state(s) to be applied for PDSCH reception based on the comparison result. A terminal that does not support two default beams may mean a terminal that has not reported the capability of two default beams for single DCI-based mTRP communication to the base station. If the terminal supports two default beams (e.g., if the terminal has reported the capability of two default beams for single DCI-based mTRP communication to the base station), the terminal may receive PDSCH regardless of the comparison result of the time duration and the scheduling offset. If the end time of the scheduling offset is before the end time of the time duration (e.g., if the PDSCH occasion starts before the end time of the time duration), the terminal may determine to apply a first indicated TCI state (e.g., a first indicated joint/DL TCI state) for PDSCH reception. The first indicated TCI state can be pre-indicated to the terminal by signaling from the base station (e.g., RRC signaling and/or MAC CE signaling).

If the end point of the scheduling offset is after the end point of the time duration (for example, if the PDSCH occasion starts after the end point of the time duration), the terminal may determine that the TCI state(s) indicated by the TCI field and/or the TCI selection field included in the DCI, the TCI state(s) indicated by the signaling of the base station (for example, RRC signaling and/or MAC CE signaling), or the first indicated TCI state is applied for PDSCH reception.

The TCI state(s) indicated by the signaling of the base station (e.g., applyIndicatedTCIState ) can be the first indicated TCI state, the second indicated TCI state, or "both the first indicated TCI state and the second indicated TCI state". "If the end time of the scheduling offset is after the end time of the time duration and the PDSCH (e.g., the PDSCH occasion) is scheduled by DCI format 1_0", the UE can determine that the TCI state(s) indicated by the signaling of the base station are applied for PDSCH reception. applyIndicatedTCIState can be applyIndicatedTCI-StateDCI-1-0 , and applyIndicatedTCI-StateDCI-1-0 can indicate the TCI state(s) used for PDSCH reception.

"If the end time of the scheduling offset is after the end time of the time duration, the PDSCH (e.g., the PDSCH occasion) is scheduled by DCI format 1_0, and the TCI state(s) are not indicated by the base station (e.g., the applyIndicatedTCIState is not set to the terminal)", the terminal may determine that the first indicated TCI state is applied for PDSCH reception.

"If an end time of a scheduling offset is after an end time of a time duration, and a PDSCH (e.g., a PDSCH occasion) is scheduled by DCI format 1_1 or DCI format 1_2, and the DCI format 1_1 or DCI format 1_2 does not include a TCI selection field," the UE may determine that both the first indicated TCI state and the second indicated TCI state are applied for PDSCH reception.

"If an end time of a scheduling offset is after an end time of a time duration, and a PDSCH (e.g., a PDSCH occasion) is scheduled by DCI format 1_1 or DCI format 1_2, and the DCI format 1_1 or DCI format 1_2 includes a TCI selection field", the UE may determine TCI state(s) applicable for PDSCH reception based on a value of a codepoint of the TCI selection field. If the codepoint of the TCI selection field is 00, the UE may determine that a first indicated joint/DL state among two indicated joint/DL TCI states is applicable for PDSCH reception (e.g., all PDSCH DM-RS port(s) of the PDSCH occasion(s)). If the code point of the TCI selection field is 01, the terminal may determine that the second indicated joint/DL state among the two indicated joint/DL TCI states is applied for PDSCH reception (e.g., all PDSCH DM-RS port(s) of the PDSCH occasion(s)). If the code point of the TCI selection field is 01, the terminal may determine that both of the two indicated joint/DL TCI states are applied for PDSCH reception.

In S1106, the base station may transmit the PDSCH to the terminal through the first TRP and/or the second TRP, and the terminal may receive the PDSCH based on the determined TCI state(s). The PDSCH may be transmitted in a PDSCH occasion scheduled by the DCI.

The operation of the method according to the present disclosure can be implemented as a computer-readable program or code on a computer-readable recording medium. The computer-readable recording medium includes all types of recording devices that store information that can be read by a computer system. In addition, the computer-readable recording medium can be distributed over network-connected computer systems so that the computer-readable program or code can be stored and executed in a distributed manner.

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

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

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

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

Claims (20)

As a method of UE (user equipment), A step of receiving DCI (downlink control information) of a base station through a first TRP (transmission and reception point) or a second TRP; A step of determining a scheduling offset between the DCI and a PDSCH occasion scheduled by the DCI based on PDSCH (physical downlink shared channel) scheduling information included in the DCI; A step of determining one or more transmission configuration indicator (TCI) states for one or more PDSCH receptions based on a comparison result between the scheduling offset and the time duration; and A step of receiving one or more PDSCHs of the base station through at least one of the first TRP or the second TRP based on the one or more TCI states, UE's method. In claim 1, If the UE does not support two default beams, the one or more TCI states are determined based on the comparison result between the scheduling offset and the time duration, and if the UE supports two default beams, the one or more TCI states are determined regardless of the comparison result between the scheduling offset and the time duration. UE's method. In claim 1, If the end time of the scheduling offset is before the end time of the time duration, the one or more TCI states for the one or more PDSCH receptions are determined as the first indicated TCI state set to the UE. UE's method. In claim 1, "If the end time of the scheduling offset is after the end time of the time duration, and the format of the DCI is DCI format 1_0", the one or more TCI states for the one or more PDSCH receptions are determined as one or more TCI states indicated by signaling of the base station. UE's method. In claim 1, "If the end time of the scheduling offset is after the end time of the time duration, the format of the DCI is DCI format 1_0, and the one or more TCI states are not indicated by signaling of the base station", the one or more TCI states for the one or more PDSCH receptions are determined as a first indicated TCI state set in the UE. UE's method. In claim 1, "If the end time of the scheduling offset is after the end time of the time duration, and the format of the DCI is DCI format 1_1 or DCI format 1_2, and the DCI format 1_1 or the DCI format 1_2 does not include a TCI selection field", the one or more TCI states for the one or more PDSCH receptions are determined by a first indicated TCI state and a second indicated TCI state set for the UE. UE's method. In claim 1, "If the end time of the scheduling offset is after the end time of the time duration, and the format of the DCI is DCI format 1_1 or DCI format 1_2, and the DCI format 1_1 or the DCI format 1_2 includes a TCI selection field", the one or more TCI states for the one or more PDSCH receptions are determined based on the value of the code point of the TCI selection field. UE's method. In claim 1, a step of determining the time duration indicating the application time of the TCI state; and Further comprising the step of transmitting information about the time duration to the base station through at least one of the first TRP or the second TRP, The above time duration includes an additional correction time required for beam setting for one or more PDSCHs having different numerologies. UE's method. In claim 1, The time duration is determined based on the sum of the time required for reception of the DCI and the time required for preparation for reception of the one or more PDSCHs based on the DCI, and the start time of the time duration is the start time or the end time of the DCI, and the start time of the time duration is preset by at least one of the UE or the base station. UE's method. In claim 1, The start time of the scheduling offset is the start time or the end time of the DCI, the end time of the scheduling offset is the start time or the end time of the PDSCH occasion, and each of the start time and the end time of the scheduling offset is preset by at least one of the UE or the base station. UE's method. As a UE (user equipment), Contains at least one processor, At least one processor of the UE, Receive DCI (downlink control information) of a base station through the first TRP (transmission and reception point) or the second TRP; Determine a scheduling offset between the DCI and a PDSCH occasion scheduled by the DCI based on PDSCH (physical downlink shared channel) scheduling information included in the DCI; determining one or more transmission configuration indicator (TCI) states for one or more PDSCH receptions based on a comparison result between the scheduling offset and the time duration; and Causing the base station to receive one or more PDSCHs through at least one of the first TRP or the second TRP based on one or more of the TCI states. UE. In claim 11, If the UE does not support two default beams, the one or more TCI states are determined based on the comparison result between the scheduling offset and the time duration, and if the UE supports two default beams, the one or more TCI states are determined regardless of the comparison result between the scheduling offset and the time duration. UE. In claim 11, If the end time of the scheduling offset is before the end time of the time duration, the one or more TCI states for the one or more PDSCH receptions are determined as the first indicated TCI state set to the UE. UE. In claim 11, "If the end time of the scheduling offset is after the end time of the time duration, and the format of the DCI is DCI format 1_0", the one or more TCI states for the one or more PDSCH receptions are determined as one or more TCI states indicated by signaling of the base station. UE. In claim 11, "If the end time of the scheduling offset is after the end time of the time duration, the format of the DCI is DCI format 1_0, and the one or more TCI states are not indicated by signaling of the base station", the one or more TCI states for the one or more PDSCH receptions are determined as a first indicated TCI state set in the UE. UE. In claim 11, "If the end time of the scheduling offset is after the end time of the time duration, and the format of the DCI is DCI format 1_1 or DCI format 1_2, and the DCI format 1_1 or the DCI format 1_2 does not include a TCI selection field", the one or more TCI states for the one or more PDSCH receptions are determined by a first indicated TCI state and a second indicated TCI state set for the UE. UE. In claim 11, "If the end time of the scheduling offset is after the end time of the time duration, and the format of the DCI is DCI format 1_1 or DCI format 1_2, and the DCI format 1_1 or the DCI format 1_2 includes a TCI selection field", the one or more TCI states for the one or more PDSCH receptions are determined based on the value of the code point of the TCI selection field. UE. In claim 11, At least one processor of the UE, Determine the above time duration indicating the application time of the TCI state; and further causing information about said time duration to be transmitted to said base station via at least one of said first TRP or said second TRP, The above time duration includes an additional correction time required for beam setting for one or more PDSCHs having different numerologies. UE. In claim 11, The time duration is determined based on the sum of the time required for reception of the DCI and the time required for preparation for reception of the one or more PDSCHs based on the DCI, and the start time of the time duration is the start time or the end time of the DCI, and the start time of the time duration is preset by at least one of the UE or the base station. UE. In claim 11, The start time of the scheduling offset is the start time or the end time of the DCI, the end time of the scheduling offset is the start time or the end time of the PDSCH occasion, and each of the start time and the end time of the scheduling offset is preset by at least one of the UE or the base station. UE.

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