WO2025033805A1 - Method and apparatus for uplink transmission in communication system - Google Patents

Abstract

A method by a UE according to an embodiment of the present disclosure may comprise the steps of: receiving first DCI from a first TRP; when the received first DCI is in a format indicating UL transmission and a first field included in the first DCI indicates UL transmission to a second TRP, identifying whether switching between sTRPs is supported; performing TRP switching to the second TRP from the first TRP supporting the switching between the sTRPs; and transmitting a PUSCH on the basis of a TCI state corresponding to the second TRP.

Description

Method and device for uplink transmission in a communication system

The present disclosure relates to improved communication technologies, and more particularly to uplink transmission technologies.

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, in a communication system, transmission and reception points (TRPs) can be used to expand communication coverage, resolve problems of communication impossibility and/or potential channel blocking in shadow areas, and provide spatial diversity effects.

In a communication system using TRPs, a terminal may communicate with one TRP or may communicate with multiple TRPs. There may be cases where a terminal must communicate with multiple TRPs while communicating with one TRP, or where a terminal must communicate with one TRP while communicating with multiple TRPs, or where a terminal must communicate with another TRP while communicating with one TRP.

In situations like the above, a terminal may need a method to provide procedures and control information that can determine which TRP to maintain a connection with or to switch a connection to.

The purpose of the present disclosure to solve the above problems is to provide a method and device for a terminal to switch between transmission and reception points (TRPs) in a communication system.

According to a first embodiment of the present disclosure for achieving the above object, a method of a user equipment (UE) may include: receiving first downlink control information (DCI) from a first transmission and reception point (TRP); determining whether single TRP (sTRP) switching is supported when the received first DCI is in a format indicating uplink (UL) transmission and a first field included in the first DCI indicates UL transmission to a second TRP; performing TRP switching from the first TRP supporting the sTRP switching to the second TRP; and transmitting a physical uplink shared channel (PUSCH) based on a transmission configuration indication (TCI) state corresponding to the second TRP.

The above first DCI further includes a TCI state indication field indicating a first TCI state (1 ^st joint/UL TCI state) and a second TCI state (2 ^nd joint/UL TCI state) for UL transmission, and the second PUSCH transmitted with the second TRP can be transmitted based on either the first TCI state or the second TCI state.

The above TCI status may be determined by a TCI status indication field included in the second DCI most recently received among the DCIs for downlink (DL) transmission received before receiving the first DCI.

The above TCI state indication field may further include a first TCI state (1 ^st joint/UL TCI state) and a second TCI state (2 ^nd joint/UL TCI state) for UL transmission.

The method may further include a step of transmitting the PUSCH to the first TRP based on a TCI state for UL transmission included in a radio resource control (RRC) message for receiving the first DCI when the first field indicates UL transmission to the second TRP and switching between the sTRPs is not supported.

The method may further include a step of transmitting the PUSCH to the first TRP based on a TCI state for UL transmission included in a second DCI most recently received among DCIs received before receiving the first DCI, if the first field indicates UL transmission to the second TRP and switching between the sTRPs is not supported.

The method may further include a step of transmitting physical uplink shared channels (PUSCHs) to each of the first TRP and the second TRP based on TCI states corresponding to each of the first TRP and the second TRP, when the received first DCI is in a format indicating uplink (UL) transmission and the first field indicates UL transmission to both the first TRP and the second TRP.

The first TCI state corresponding to the first TRP may be one of a first TCI state (1 ^st joint/UL TCI state) or a second TCI state (2 ^nd joint/UL TCI state) included in the first DCI, and the second TCI state corresponding to the second TRP may be a TCI state different from the TCI state applied to the first TRP among the first TCI state or the second TCI state.

The first TCI state corresponding to the first TRP may be either a first TCI state (1 ^st joint/UL TCI state) or a second TCI state (2 ^nd joint/UL TCI state) included in a second DCI most recently received among DCIs received before receiving the first DCI, and the second TCI state corresponding to the second TRP may be a TCI state different from the TCI state applied to the first TRP among the first TCI state or the second TCI state.

The first field is a sounding reference signal (SRS) resource set indicator field consisting of 2 bits, and when 2 bits of the SRS resource indicator set indicate "00", it indicates transmission of the PUSCH to a TRP currently being communicated, and when 2 bits of the SRS resource indicator set indicate "01", it indicates transmission of the PUSCH to the second TRP, and when 2 bits of the SRS resource indicator set indicate "10" or "11", it can indicate transmission of the PUSCHs to the first TRP and the second TRP.

A user equipment (UE) according to one embodiment of the present disclosure comprises at least one processor, wherein the UE:

A method for receiving a first downlink control information (DCI) from a first transmission and reception point (TRP); determining whether single TRP (sTRP) switching is supported when the received first DCI is in a format indicating uplink (UL) transmission and a first field included in the first DCI indicates UL transmission to a second TRP; performing TRP switching from the first TRP supporting the sTRP switching to the second TRP; and causing a physical uplink shared channel (PUSCH) to be transmitted based on a transmission configuration indication (TCI) state corresponding to the second TRP.

The above first DCI further includes a TCI state indication field indicating a first TCI state (1 ^st joint/UL TCI state) and a second TCI state (2 ^nd joint/UL TCI state) for UL transmission, and the second PUSCH transmitted with the second TRP can be transmitted based on either the first TCI state or the second TCI state.

The above TCI status may be determined by a TCI status indication field included in the second DCI most recently received among the DCIs for downlink (DL) transmission received before receiving the first DCI.

The above TCI state indication field may further include a first TCI state (1 ^st joint/UL TCI state) and a second TCI state (2 ^nd joint/UL TCI state) for UL transmission.

At least one processor of the UE:

The first field may further cause the PUSCH to be transmitted to the first TRP based on a TCI state for UL transmission included in a radio resource control (RRC) message for receiving the first DCI if the first field indicates UL transmission to the second TRP and switching between the sTRPs is not supported.

At least one processor of the UE:

If the first field indicates UL transmission to the second TRP and switching between the sTRPs is not supported, the PUSCH may be further caused to be transmitted to the first TRP based on a TCI state for UL transmission included in a second DCI most recently received among DCIs received before receiving the first DCI.

At least one processor of the UE:

If the received first DCI is in a format indicating uplink (UL) transmission, and the first field indicates UL transmission to both the first TRP and the second TRP, the method may further cause physical uplink shared channels (PUSCHs) to be transmitted to each of the first TRP and the second TRP based on TCI states corresponding to each of the first TRP and the second TRP.

The first TCI state corresponding to the first TRP may be one of a first TCI state (1 ^st joint/UL TCI state) or a second TCI state (2 ^nd joint/UL TCI state) included in the first DCI, and the second TCI state corresponding to the second TRP may be a TCI state different from the TCI state applied to the first TRP among the first TCI state or the second TCI state.

The first TCI state corresponding to the first TRP may be either a first TCI state (1 ^st joint/UL TCI state) or a second TCI state (2 ^nd joint/UL TCI state) included in a second DCI most recently received among DCIs received before receiving the first DCI, and the second TCI state corresponding to the second TRP may be a TCI state different from the TCI state applied to the first TRP among the first TCI state or the second TCI state.

The first field is a sounding reference signal (SRS) resource set indicator field consisting of 2 bits, and when 2 bits of the SRS resource indicator set indicate "00", it indicates transmission of the PUSCH to a TRP currently being communicated, and when 2 bits of the SRS resource indicator set indicate "01", it indicates transmission of the PUSCH to the second TRP, and when 2 bits of the SRS resource indicator set indicate "10" or "11", it can indicate transmission of the PUSCHs to the first TRP and the second TRP.

According to the present disclosure, a procedure is provided for a UE to dynamically switch to a single TRP (sTRP) based on a DCI for uplink transmission while communicating with multiple TRPs (mTRPs). In addition, according to the present disclosure, dynamic switching to another TRP can be performed while communicating with an sTRP, and in this case, the present disclosure provides a procedure and an operation in the UE when switching from one TRP to another TRP. If switching from one TRP to another TRP is not supported, the present disclosure provides a method for performing uplink transmission to an existing TRP to remove ambiguity. Therefore, the present disclosure has an advantage of removing ambiguity in TRP switching operation by providing whether TRP switching is allowed in an sTRP environment and an operation method of the UE based on the allowance.

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

FIG. 2 is a block diagram illustrating a first embodiment of a communication node constituting a communication system.

FIG. 3 is a block diagram illustrating a first embodiment of communication nodes performing communication.

FIG. 4a is a block diagram illustrating a first embodiment of a transmission path.

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

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

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

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

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

Figure 9a is a conceptual diagram illustrating a case where a UE communicates with two different TRPs through their respective links.

FIG. 9b is a conceptual diagram illustrating a first embodiment in which a UE communicates with one of two different TRPs via a communication link formed with the TRP.

FIG. 9c is a conceptual diagram illustrating a second embodiment in which a UE communicates over a communication link formed with one of two different TRPs.

FIG. 9d is a conceptual diagram illustrating a first embodiment in which a UE communicates over a communication link formed with one of three different TRPs.

Figure 10 is a flowchart for explaining the dynamic switching operation between mTRP and sTRP.

Figure 11 is a flowchart of the operation of a UE according to the first method when switching from mTRP to sTRP and then switching to sTRP is possible.

FIG. 12 is a flowchart for explaining a case of transmitting a PUSCH based on reception of control information according to the second method of the present disclosure.

FIG. 13 is a flowchart for explaining a case of transmitting a PUSCH based on reception of control information according to the third method of the present disclosure.

FIG. 14 is a flowchart for explaining a case of transmitting a PUSCH based on reception of control information according to the fourth method of the present disclosure.

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 be limiting of 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 an RRC message. MAC signaling may refer to a transmission and reception operation of a MAC control element (CE). PHY signaling may refer to a transmission and reception operation of control information (e.g., downlink control information (DCI), uplink control information (UCI), sidelink control information (SCI)).

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 a first embodiment 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 a first embodiment of a communication node 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.

FIG. 3 is a block diagram illustrating a first embodiment 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 a first embodiment of a transmission path, and FIG. 4b is a block diagram illustrating a first embodiment 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 a first embodiment 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 a first embodiment of a subframe 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 a first embodiment of a slot 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.

Subcarrier spacing 15 kHz 30 kHz 60 kHz 120 kHz 240 kHz 480 kHz OFDM
Symbol length [μs] 66.7 33.3 16.7 8.3 4.2 2.1 CP length [μs] 4.76 2.38 1.19 0.60 0.30 0.15 Number of OFDM symbols in 1ms 14 28 56 112 224 448

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

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 a first embodiment 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 wireless communication system using a Transmission and Reception Point (TRP) can communicate between a multi-TRP (mTRP) and user equipment (UE) in a single-frequency network (SFN) or spatial division multiplexing (SDM) manner based on a single downlink control information (DCI) (sDCI). At this time, the communication can include downlink (DL) transmission and uplink (UL) transmission. When the UE performs UL communication with the mTRP in the SFN or SDM manner, transmission can be performed through simultaneous transmission across multi-panels (STxMP).

A UE can transmit an uplink, for example, a physical uplink shared channel (PUSCH), in the sDCI-based mTRP SFN/SDM scheme. In this situation, according to the agreement in the current 3GPP standard meeting, the UE can dynamically switch from sDCI-based mTRP SFN/SDM-based PUSCH transmission to sTRP PUSCH transmission. However, the agreement in the 3GPP standard meeting only mentions that dynamic switching from sDCI-based mTRP SFN/SDM-based PUSCH to sTRP PUSCH is possible, and no specific method has been proposed yet. Therefore, the present disclosure described below will look into a method for performing a procedure for dynamic switching of uplink transmission.

Figure 9a is a conceptual diagram illustrating a case where a UE communicates with two different TRPs through each link.

Referring to FIG. 9A, a UE (901) and a first TRP (910) and a second TRP (920) are illustrated. The UE (901) may include all or part of the configurations described above in FIG. 2. In addition, the UE (901) may further include configurations not illustrated in FIG. 2. For example, the UE (901) may further include various sensors, user interfaces, etc. for the convenience of the user.

The first TRP (910) and/or the second TRP (920) may be a remote node connected to an upper base station. Accordingly, the first TRP (910) and/or the second TRP (920) may include at least some of the configurations illustrated in FIG. 2, and may further include other configurations not illustrated in FIG. 2, for example, a configuration for interfacing with an upper node and/or a configuration for interfacing with another TRP. Each of the first TRP (910) and the second TRP (920) may form a beam through a plurality of antennas, and may form a beam in a specific direction for communicating with the UE (901).

Referring to FIG. 9A, a UE (901) sets up a first TRP (910) and a first communication channel (911), and is expected to communicate with the first TRP (910). Here, the communication channel between the UE (901) and the first TRP (910) may include a physical downlink control channel (PDCCH) and/or a physical downlink shared channel (PDSCH) in the case of downlink. In addition, the communication channel between the UE (901) and the first TRP (910) may include a PUCCH and/or a PUSCH in the case of uplink. Referring to FIG. 9A, a UE (901) sets up a second TRP (920) and a second communication channel (921), and is expected to communicate with the second TRP (920). Here, the communication channel between the UE (901) and the second TRP (920) may include a PDCCH and/or a PDSCH for the downlink, and a PUCCH and/or a PUSCH for the uplink.

The embodiment of FIG. 9a described above may be an example for an mTRP environment since the UE (901) is in communication with both the first TRP (910) and the second TRP (920).

FIG. 9b is a conceptual diagram illustrating a first embodiment in which a UE communicates with one of two different TRPs via a communication link formed with one TRP, FIG. 9c is a conceptual diagram illustrating a second embodiment in which a UE communicates with one of two different TRPs via a communication link formed with one TRP, and FIG. 9d is a conceptual diagram illustrating a first embodiment in which a UE communicates with one of three different TRPs via a communication link formed with one TRP.

The UE (901) and the first TRP (910) and the second TRP (920) illustrated in FIGS. 9b, 9c and 9d may all have the same configuration as described in FIG. 9a. In addition, FIG. 9d illustrates a configuration further including a third TRP (930). The third TRP (930) may have the same configuration as the first TRP (910) and/or the second TRP (920) illustrated in FIG. 9a.

First, referring to FIG. 9b, a case is exemplified where a UE (901) establishes a first communication channel (911) with a first TRP (910) among the first TRP (910) and the second TRP (920). The communication channel between the UE (901) and the first TRP (910) may include a PDCCH and/or a PDSCH in the case of downlink, as described above, and may include a PUCCH and/or a PUSCH in the case of uplink. As exemplified in FIG. 9b, the UE (901) is an example in which a communication channel is established with the first TRP (910), but a communication channel is not established with the second TRP (920). Therefore, the embodiment of FIG. 9b may be an example in which a UE (901) communicates in an sTRP environment.

Referring to FIG. 9c, the UE (901) sets a second communication channel (921) with the second TRP (920) among the first TRP (910) and the second TRP (920). The communication channel between the UE (901) and the second TRP (920) may also include a PDCCH and/or a PDSCH in the downlink as described above, and may include a PUCCH and/or a PUSCH in the uplink. As illustrated in FIG. 9c, the UE (901) is an example in which a communication channel is set with the second TRP (920), but a communication channel is not set with the first TRP (910). Therefore, the embodiment of FIG. 9c may be another example in which the UE (901) communicates in an sTRP environment.

Referring to FIG. 9d, the UE (901) sets a third communication channel (931) with the third TRP (930) among the first TRP (910), the second TRP (920), and the third TRP (930). The communication channel between the UE (901) and the third TRP (930) may also include a PDCCH and/or a PDSCH for the downlink, as described above, and may include a PUCCH and/or a PUSCH for the uplink. As illustrated in FIG. 9d, the UE (901) is an example in which a communication channel is set with the third TRP (930), but no communication channels are set with the first TRP (910) and the second TRP (920). Therefore, the embodiment of FIG. 9d may also be another example in which the UE (901) communicates in an sTRP environment.

Figure 10 is a flowchart for explaining the dynamic switching operation between mTRP and sTRP.

Referring to Fig. 10, a first TRP, a second TRP, and a UE are illustrated. The first TRP, the second TRP, and the UE may have the same configuration as described above in Figs. 9a to 9d.

Steps S1000a and S1000b illustrate a situation in which the UE communicates with the first TRP and the second TRP. Accordingly, the UE can perform downlink communication and/or uplink communication with the first TRP and the second TRP.

In step S1000a, the first TRP can transmit a PDCCH and/or a PDSCH to the UE via a specific beam. Therefore, the UE can receive the PDCCH and/or the PDSCH via the beam formed by the first TRP. In addition, the UE can transmit a PUCCH and/or a PUSCH to the first TRP via a specific beam. Therefore, the first TRP can receive the PUCCH and/or the PUSCH via the beam formed by the UE.

In step S1000b, the second TRP can transmit PDCCH and/or PDSCH to the UE via a specific beam. Therefore, the UE can receive PDCCH and/or PDSCH via the beam formed by the second TRP. In addition, the UE can transmit PUCCH and/or PUSCH to the second TRP via a specific beam. Therefore, the second TRP can receive PUCCH and/or PUSCH via the beam formed by the UE.

In steps S1000a and S1000b, the UE may be in a state of communicating with mTRP since it is in an environment of communicating with the first TRP and the second TRP.

In step S1002, the first TRP may transmit switching instruction information to the UE to indicate switching to the sTRP. The switching instruction information to the sTRP may be, for example, information included in the DCI. Therefore, the UE may receive switching instruction information from the first TRP to the sTRP in step S1002. As described above, step S1002 is a case where the UE is communicating with two different TRPs and thus communicating in an mTRP environment. In addition, since the UE is instructed to switch to the sTRP by the DCI transmitted from the first TRP, it may be a case where a single DCI (sDCI) is used. In other words, step S1002 may be a case where dynamic switching from an mTRP to an sTRP is indicated using the sDCI.

In this disclosure, it is assumed that the switching indication information to sTRP is indicated by a sounding reference signal (SRS) resource set indicator included in DCI. The 3GPP standard stipulates that the SRS resource set indicator can be set to 0 bits or 2 bits. Accordingly, when the SRS resource set indicator in the DCI is set to 2 bits, the SRS resource set indicator can be set to one of four values: "00", "01", "10", or "11". In this disclosure, it is assumed that the case in which the SRS resource set indicator is set to "00" indicates switching from mTRP to sTRP.

In step S1004, the UE may perform a switching procedure to sTRP based on the received indication information. At this time, when determining a TRP that can be communicated, the UE may determine the TRP based on a transmission configuration indication (TCI) state activated by MAC-CE and/or indicated by DCI among the transmission configuration indication (TCI) states set in a radio resource control (RRC) message.

The example of Fig. 10 illustrates a case where the first TRP is set as an sTRP to communicate with the UE. However, the second TRP may also be set as a TRP to communicate with the UE. For convenience of explanation, the following explanation will assume the case where the first TRP is set as an sTRP to communicate with the UE.

In step S1004, the UE may perform a switching procedure to sTRP based on the received switching instruction information. In the example of Fig. 10, it is assumed that the first TRP is determined as one TRP to communicate with, so the sTRP to communicate with may be the first TRP. Therefore, the UE must terminate the connection with the second TRP in step S1004. It should be noted that the example of Fig. 10 does not illustrate a communication termination procedure between the UE and the second TRP.

In step S1006, the UE can communicate with the first TRP. In other words, the UE can receive PDCCH/PDSCH from the first TRP through a specific beam in the case of downlink (DL), and can transmit PUCCH/PUSCH to the first TRP through a specific beam in the case of uplink (UL).

The procedure described above can be a switching operation from an mTRP environment to an sTRP environment, as in the situation of FIG. 9a, as in the situation of FIG. 9b. In other words, the UE can be switched from communicating with the first TRP and the second TRP, as in the situation of FIG. 9a, to communicating only with the first TRP, as in the situation of FIG. 9b, based on a switching instruction set in the DCI to the sTRP.

In the example of Fig. 10, it is assumed that the first TRP communicates with the UE when switching from an mTRP environment to an sTRP environment. However, the second TRP may be selected when switching from an mTRP environment to an sTRP environment. If the second TRP is selected when switching from an mTRP environment to an sTRP environment, dynamic switching of TRPs may be performed from the situation of Fig. 9a to the situation of Fig. 9c.

As another example of dynamic switching of TRPs, the UE may perform TRP dynamic switching in a state where it communicates with a third TRP as illustrated in FIG. 9d based on a switching instruction set in sDCI while communicating with the first TRP and the second TRP as illustrated in FIG. 9a. When dynamic switching to the third TRP is performed, the UE may perform a connection procedure with the third TRP in step S1004. In addition, when dynamic switching to the third TRP is performed, the UE may perform a connection release procedure with the first TRP and the second TRP in step S1004.

Meanwhile, dynamic switching operation from sTRP to mTRP may also be possible.

In step S1006, the UE may be in a state of communicating only with the first TRP. Thereafter, at a specific point in time, for example, in step S1010, the first TRP may instruct the UE to switch TRP to mTRP. Therefore, in step S1010, the UE may receive switching instruction information from the first TRP to mTRP. The switching instruction to mTRP may be instructed by sDCI as described above. In the present disclosure, if the SRS resource set indicator is set to 2 bits in the DCI, any value except "00" described above may be utilized for the switching instruction to mTRP. In other words, if the SRS resource set indicator is set to 2 bits in the DCI, any one of "01", "10", or "11" may be utilized for the instruction. This utilization method may be additionally confirmed based on the description below.

In step S1012, the UE can perform a switching procedure to mTRP. In other words, it can connect to an additional TRP other than the first TRP with which it is currently communicating. In the example of Fig. 10, an additional connection to the second TRP is exemplified. The example of Fig. 10 is one embodiment, and when dynamically switching TRPs from an sTRP environment to an mTRP environment, an additional connection to a third TRP other than the second TRP may be made.

In steps S1014a and S1014b, the UE can communicate with the first TRP and the second TRP. In other words, the UE can perform transmission and reception of DL/UL signals and/or data with the first TRP, and can perform transmission and reception of DL/UL signals and/or data with the second TRP.

Meanwhile, the above description describes dynamic switching from an mTRP environment to an sTRP environment and from an sTRP environment to an mTRP environment. However, it does not mention whether switching to another TRP (sTR) is possible or impossible after switching from an mTRP environment to an sTRP environment. Also, a specific method is not presented on how to perform dynamic switching of a TRP from an mTRP environment to an sTRP. Therefore, the present disclosure described below will describe a method for a procedure for switching to another sTRP after switching from an mTRP environment to an sTRP environment. In addition, the present disclosure described below will describe an additional method for dynamic switching of a TRP from an mTRP to an sTRP environment in addition to the method described above.

Different definitions may be required for the cases where switching to another sTRP is possible after dynamic switching from an mTRP to an sTRP and the cases where switching to another sTRP is impossible. Therefore, in this disclosure, the cases where switching to another sTRP is possible after dynamic switching from an mTRP to an sTRP and the cases where switching to another sTRP is impossible after dynamic switching from an mTRP to an sTRP are examined separately.

(1) When switching from mTRP to sTRP and then switching to sTRP is possible

[Method 1]

Below, a first method is described in which switching from mTRP to sTRP and then switching to sTRP is possible. In addition, in the first method according to the present disclosure described below, an operation in which a UE transmits a PUSCH is described.

Figure 11 is a flowchart of the operation of a UE according to the first method when switching from mTRP to sTRP and then switching to sTRP is possible.

The operation of Fig. 11 may be an operation performed when a UE wishes to transmit a PUSCH in a state where switching has occurred from mTRP to sTRP. For convenience of explanation, the following description will assume a case where the UE communicates with the first TRP as described in Fig. 10.

In step S1100, the UE may receive DCI from the first TRP. As shown in FIG. 11, since the UE is considering transmitting a PUSCH, the UE may expect to receive DCI format 0_1 or DCI format 0_2 including uplink transmission control information. The DCI format 0_1 or DCI format 0_2 according to the present disclosure may include a TCI state indication field, an SRS resource set indicator field, two SRS resource indicator (SRI) fields, and two transmit precoding matrix indicator (TPMI) fields.

If DCI format 0_1 or DCI format 0_2 does not include the TCI status indication field among the above information, the DCI including the TCI status indication field among the most recently received DCIs can be used. The DCI including the TCI status indication field may be, for example, DCI including UE downlink transmission control information. As a more specific example, the DCI including the TCI status indication field can use the TCI status indication field included in any one of DCI format 1_1, DCI format 1_2, or DCI format 1_3.

In addition, in step S1100, the UE may perform blind decoding on the DCI received from the first TRP. The blind decoding may be performed based on the size of the DCI and the fields included in the DCI. In the present disclosure, since the DCI assumes PUSCH transmission, the received DCI may be in DCI format 0_1 or DCI format 0_2.

In step S1102, the UE can check each field of the decoded DCI, that is, DCI format 0_1 or DCI format 0_2. The present disclosure stipulates a switching operation from mTRP to sTRP and then back to sTRP. In addition, the present disclosure describes an example of a case in which switching is indicated using an SRS resource set indicator when switching from sTRP to another sTRP.

In step S1104, the UE can check whether the SRS resource set indicator has a value of "00". If the SRS resource set indicator has a value of "00", the UE can proceed to step S1106 and transmit the PUSCH based on the first indicated UL TCI state (joint/UL TCI state) among the fields indicating TCI states in the DCI. If, in step S1104, the UE does not indicate the SRS resource set indicator with a value of "00", the UE can proceed to step S1110.

In step S1110, the UE can check whether the SRS resource set indicator has a value of "01". If the SRS resource set indicator has a value of "01", the UE can proceed to step S1112 and transmit the PUSCH based on the second indicated joint/UL TCI state among the fields indicating TCI states in the DCI. If the SRS resource set indicator does not have a value of "01" in step S1110, the SRS resource set indicator may have a value of "10" or "11". Therefore, in the present disclosure, if the SRS resource set indicator has a value of "10" or "11", the UE can proceed to step S1114.

In step S1114, the UE can switch to mTRP and transmit PUSCHs to each TRP based on the first indicated joint/UL TCI state and the second indicated joint/UL TCI state among the fields indicating TCI states in the DCI, since the SRS resource set indicator has a value of "10" or "11".

Therefore, when the SRS resource set indicator has a value of "10" or "11", it can correspond to the case where switching is indicated from sTRP to mTRP.

Meanwhile, the present disclosure assumes a case where switching from sTRP to mTRP is indicated when the SRS resource set indicator has a value of "10" or "11". However, if the case where the SRS resource set indicator indicates "11" is left in a reserved state, the case where the SRS resource set indicator indicates "11" is ignored and PUSCH transmission may be abandoned.

[Method 2]

In the following, the switching operation from sTRP to sTRP, sTRP to mTRP, or mTRP to sTRP is described when switching from mTRP to sTRP and then switching to sTRP is possible. In particular, the second method described below describes the operation in which the UE transmits a PUSCH.

Since the second method of the present disclosure describes an operation of transmitting a PUSCH, it is assumed that DCI format 0_1 and/or DCI format 0_2 have the following two subformats.

A. If DCI format 0_1 and/or DCI format 0_2 is the first sub-format, either the first option or the second option may be used.

A1. Some of the information added to or included in DCI format 0_1 and/or DCI format 0_2 when DCI format 0_1 and/or DCI format 0_2 is the first option of the first subformat are as follows:

TCI state indication field, first SRS resource indicator (SRI), TPMI field

A2. Some of the information that is added to or included in DCI Format 0_1 and/or DCI Format 0_2 when DCI Format 0_1 and/or DCI Format 0_2 is the second option of the first subformat are as follows:

TCI Status Indication field, first SRI, second SRI (defined by reserved bits), first TPMI, and second TPMI (defined by reserved bits) fields.

If the DCI format 0_1 and/or DCI format 0_2 exemplified above is one of the first option or the second option of the first subformat, there may be fields that overlap with fields defined in the 3GPP standard, and there may also be fields that need to be newly added. For example, the current 3GPP standard does not define a TCI status indication field in the DCI format 0_1 or the DCI format 0_2. Therefore, in order to apply the second method of the present disclosure, the DCI format 0_1 or the DCI format 0_2 may need to be modified to include the TCI status indication field.

As another example, since DCI format 0_1 or DCI format 0_2 in the current 3GPP standard does not include a TCI status indication field, DCI format 0_1 or DCI format 0_2 can be configured not to include a TCI status indication field. In this case, the TCI status indication field of DCI format 0_1 or DCI format 0_2 can use or be inferred from the TCI status indication field included in any one of DCI format 1_1, DCI format 1_2 or DCI format 1_3 containing the most recently received downlink control information. This can be understood in the same way as described in the first method. This inferred method can be equally applied when there are other fields not specified in the DCI for UL transmission, although additional fields are required besides the TCI status indication field.

B. Some examples of information according to the second method of the present disclosure, when DCI format 0_1 and/or DCI format 0_2 is the second sub-format, are as follows:

TCI status indication field, SRS resource set indicator, first SRI, second SRI, first TPMI field, second TPMI field

The second method of the present disclosure described below describes a procedure for a UE to transmit a PUSCH in uplink when subformats of the DCI format 0_1 and/or DCI format 0_2 described above are used.

FIG. 12 is a flowchart for explaining a case of transmitting a PUSCH based on reception of control information according to the second method of the present disclosure.

In explaining the flowchart of Fig. 12, it may be an operation for a case where the UE wants to transmit a PUSCH. In addition, when the operation of the UE is described in Fig. 12, the operation of the TRP corresponding thereto may be performed. For example, when the UE receives a specific DCI, the TRP may generate the corresponding DCI and transmit it to the UE, or receive the corresponding DCI from an upper node and transmit it to the UE. Conversely, when the UE transmits a specific signal, for example, a PUSCH, the TRP may receive the PUSCH. In addition, the present disclosure assumes a case where sDCI is received in an mTRP environment or an sTRP environment.

In step S1202, the UE can receive sDCI from the TRP and blind decode the received DCI. Blind decoding can be performed based on the size of the DCI and the fields included in the DCI. Then, the UE can check the decoded DCI field. At this time, since the UE intends to transmit a PUSCH, it can expect to receive DCI format 0_1 or DCI format 0_2 from the sTRP.

If the UE receives the DCI format 0_1, the actual received DCI may be one of the first option of the first subformat of the DCI format 0_1, the second option of the first subformat of the DCI format 0_1, or the second subformat of the DCI format 0_1 as described above. If the UE receives the DCI format 0_2, the actual received DCI may be one of the first option of the first subformat of the DCI format 0_2, the second option of the first subformat of the DCI format 0_2, or the second subformat of the DCI format 0_2 as described above.

In explaining Fig. 12, for convenience of explanation, it is assumed that DCI format 0_1 is received. However, even if DCI format 0_2 is received, the UE can perform the same operation as in the case of DCI format 0_1 described below.

In step S1204, since the UE receives the DCI format 0_1, the UE can check whether the first subformat of the DCI format 0_1 has been received. The first subformat of the DCI format 0_1 can include fields having the first option or the second option as described above. If the check result of step S1204 indicates that the first subformat of the DCI format 0_1 has been received, the UE can perform step S1206. On the other hand, if the check result of step S1204 indicates that the received DCI format 0_1 is not the first subformat, the received DCI is the second subformat of the DCI format 0_1. If the DCI format 0_1 has additional subformats in addition to the first subformat and the second subformat of the DCI format 0_1, the UE can further include a procedure for checking whether the second subformat of the DCI format 0_1 has been received. However, since the second method of the present disclosure describes a case where only the first subformat and the second subformat of DCI format 0_1 are used, the procedure for checking whether the second subformat of DCI format 0_1 has been received is omitted.

When proceeding to step S1206, the UE can check whether the current sTRP communication is in progress. If it is in the mTRP communication, the UE can perform DCI failure processing. This is because the UE operates in an mTRP environment, and therefore the first subformat of the DCI format 0_1 for maintaining the current sTRP operation in sTRP is not a normal DCI. Therefore, in step S1204, the first subformat of the DCI format 0_1 is received, and if the result of the check in step S1206 is in the sTRP environment, the routine of FIG. 12 can be terminated. In other words, the UE can give up the PUSCH transmission at the PUSCH transmission time.

If the current state is in communication with sTRP as a result of the inspection at step S1206, the UE can perform step S1208.

When proceeding to step S1208, since the first subformat of DCI format 0_1 is received, the UE can transmit PUSCH to the currently communicating TRP without dynamic switching of the TRP. At this time, the UE can perform PUSCH transmission based on the TCI state corresponding to the RRC setting for reception of the received DCI format 0_1. The TCI state determination method can be determined as follows.

For example, assume that the first subformat of the received DCI format 0_1 includes a first TCI state (e.g., 1 ^st joint/UL TCI state) and a second TCI state (e.g., 2 ^nd joint/UL TCI state). In this case, when the first subformat of the DCI format 0_1 includes two different TCI states (1 ^st joint/UL TCI state, 2 ^nd joint/UL TCI state), the UE can determine the TCI state based on the information indicated by the received RRC message before receiving the first subformat of the DCI format 0_1. For example, when the RRC message indicates to use the first TCI state, the UE can transmit a PUSCH using the first TCI state (1 ^st joint/UL TCI state) included in the first subformat of the DCI format 0_1.

As another example, if the RRC message indicates to use the second TCI state, the UE may transmit the PUSCH using the second TCI state (2 ^nd joint/UL TCI state) included in the first subformat of DCI format 0_1.

Additionally, the first SRI and TPMI fields included in the first subformat of DCI format 0_1 can indicate SRS resources, precoding information, and number of layers corresponding to the corresponding TCI state. Based on this, the UE can transmit PUSCH.

Meanwhile, the case where the process proceeds from step S1204 to step S1210 is when the received DCI 0_1 is the second subformat of DCI format 0_1 as described above. In step S1210, the UE can check whether the SRS resource set field value included in the second subformat of DCI format 0_1 is "00". If the SRS resource set field value included in the second subformat of DCI format 0_1 is "00", the UE can proceed to step S1212, and if the SRS resource set field value included in the second subformat of DCI format 0_1 is not "00", the UE can proceed to step S1220.

In step S1212, the UE may transmit the PUSCH based on the first TCI state (e.g., 1 ^st joint/UL TCI state) among the TCI states indicated in the TCI state indication field in the second subformat of the received DCI format 0_1. At this time, the first TCI state may be, for example, a TCI state for the currently communicated TRP and PUSCH transmission.

When proceeding from step S1210 to step S1220, the SRS resource set field is not "00". Therefore, the UE can check whether the SRS resource set field is "01" in step S1220. If the SRS resource set field is "01", the UE can proceed to step S1222, and if the SRS resource set field is not "01", the UE can proceed to step S1224.

In step S1222, the UE can transmit the PUSCH based on the second TCI state (e.g., ^2nd joint/UL TCI state) among the TCI states indicated in the TCI state indication field in the second subformat of the received DCI format 0_1. At this time, the second TCI state can be, for example, a TRP other than the currently communicating TRP. In other words, TRP dynamic switching can be performed. The TRP dynamic switching procedure is described below with reference to FIGS. 9a to 9d.

As illustrated in FIG. 9b, if the TRP currently being communicated is the first TRP (910) and the TRP corresponding to the TCI state selected based on the second subformat of the DCI format 0_1 received in step S1222 is the second TRP (920), the UE may transmit a PUSCH to the second TRP (920) as illustrated in FIG. 9c. As another example, if the TRP currently being communicated is the first TRP (910) and the TRP corresponding to the TCI state selected based on the second subformat of the DCI format 0_1 received in step S1222 is the third TRP (930), the UE may transmit a PUSCH to the third TRP (930) as illustrated in FIG. 9d. In other words, step S1222 may be a procedure for performing a dynamic switching operation from an sTRP to another sTRP.

When proceeding from step S1220 to step S1224, the SRS resource set field is neither "00" nor "01". In other words, proceeding to step S1224 may be when the SRS resource set field has a value of "10" or "11". In step S1224, the UE may transmit a PUSCH with two TRPs corresponding to a first TCI state (e.g., 1 ^st joint/UL TCI state) and a second TCI state (e.g., 2 ^nd joint/UL TCI state) among the TCI states indicated in the TCI state indication field in the second subformat of the received DCI format 0_1. In other words, this may be a procedure in which dynamic switching of TRP is performed from sTRP operation to mTRP operation. The TRP dynamic switching procedure of step S1224 is described below with reference to FIGS. 9a to 9d.

As illustrated in FIG. 9b, if the TRP currently being communicated is the first TRP (910), and the TRP corresponding to the first TCI state (e.g., 1 ^st joint/UL TCI state) based on the second subformat of the DCI format 0_1 received in step S1224 is the first TRP (910), and the TRP corresponding to the second TCI state (e.g., 2 ^nd joint/UL TCI state) is the second TRP (920), then the UE can transmit a PUSCH to each of the first TRP (910) and the second TRP (920), as illustrated in FIG. 9a. At this time, the PUSCH transmitted to the first TRP (910) may be transmitted based on the first TCI state (e.g., 1 ^st joint/UL TCI state), and the PUSCH transmitted to the second TRP (920) may be transmitted based on the second TCI state (e.g., 2 ^nd joint/UL TCI state).

In explaining the second method of the present disclosure, it is explained as an example that the case where the SRS resource set indicator is "10" or "11" is interpreted in the same way. However, if the SRS resource set indicator is "11", the UE does not expect to receive "11" if it is reserved.

Meanwhile, the overall operation described above has been described assuming that sTRP is maintained in a state where it is switched from mTRP to sTRP, or that dynamic switching of TRP to another sTRP occurs, or that dynamic switching of TRP to mTRP occurs. However, the operation of Fig. 12 can be applied in the same form even in the mTRP state. Hereinafter, the operation of Fig. 12, which is the second method of the present disclosure, is described in a case where it is performed in the mTRP state.

In step S1202, the UE communicates in an mTRP environment, can receive sDCI from a specific TRP, and can blind decode the sDCI. Then, the UE can check the decoded sDCI. Since this is also a case where PUSCH transmission is intended, the UE can expect reception of DCI format 0_1 or DCI format 0_2. The operation below will be examined assuming that DCI format 0_1 is received as described above.

In step S1204, the UE can check whether the first subformat of DCI format 0_1 has been received. If the first subformat of DCI format 0_1 has been received as a result of the check in step S1204, the UE can perform DCI failure processing in step S1206 if it is an mTRP environment.

If the result of the inspection in step S1204 is not the first subformat of the DCI format 0_1, the process may proceed to step S1210. The subsequent procedures may be performed in the same manner as described above. For example, if the SRS resource set field is "00" (proceed to "Yes" in step S1210), the UE may transmit a PUSCH based on a first TCI state (e.g., 1 ^st joint/UL TCI state) among the TCI states indicated in the TCI state indication field in the second subformat of the first DCI format 0_1 in step S1212. At this time, the first TCI state may be any one of the TRPs communicating in the mTRP environment. For example, the first TCI state may be a TRP that transmitted sDCI.

If the SRS resource set field is not "00", in step S1220, the UE may check whether the SRS resource set field is "01". If the SRS resource set is "01", the UE may transmit the PUSCH based on the second TCI state (e.g., ^2nd joint/UL TCI state) among the TCI states indicated in the TCI state indication field in the second subformat of the received DCI format 0_1. In this case, the second TCI state may also be any one of the TRPs communicating in the mTRP environment. For example, the second TCI state may be another TRP communicating rather than the TRP that transmitted the sDCI.

If the SRS resource set field is neither "00" nor "01", in step S1224, the UE may transmit PUSCH with two TRPs corresponding to the first TCI state (e.g., 1 ^st joint/UL TCI state) and the second TCI state (e.g., 2 ^nd joint/UL TCI state) among the TCI states indicated in the TCI state indication field in the second subformat of the received DCI format 0_1.

[Method 3]

In the following, the switching operation from sTRP to sTRP, sTRP to mTRP, or mTRP to sTRP is described when switching from mTRP to sTRP and then switching to sTRP is possible. In particular, the second method described below describes the operation in which the UE transmits a PUSCH.

Since the third method of the present disclosure describes an operation of transmitting a PUSCH, it is assumed that DCI format 0_1 and/or DCI format 0_2 have the following two subformats.

C. If DCI format 0_1 and/or DCI format 0_2 is the third sub-format, either option 1 or option 2 may be used.

C1. Some of the information that is added to or included in DCI format 0_1 and/or DCI format 0_2 when DCI format 0_1 and/or DCI format 0_2 is the first option of the third subformat are as follows:

First SRI, first TPMI field

C2. Some of the information that is added to or included in DCI Format 0_1 and/or DCI Format 0_2 when DCI Format 0_1 and/or DCI Format 0_2 is the second option of the third subformat are as follows:

First SRI, first TPMI field, second SRI (defined by reserved bits), second TPMI field (defined by reserved bits)

If the DCI format 0_1 and/or DCI format 0_2 exemplified above is one of the first option or the second option of the third subformat, there may be fields that overlap with fields specified in the 3GPP standard, and there may also be fields that need to be newly added. If a DCI field is not currently specified in the 3GPP standard, a TCI status indication field included in any one of the DCI format 1_1, the DCI format 1_2, or the DCI format 1_3 including the most recently received downlink control information according to the third method of the present disclosure may be used. This method can also be understood in the same form as the contents described in the first method and the second method.

D. If DCI format 0_1 and/or DCI format 0_2 is the 4th sub-format.

Some examples of information that are added to or included in DCI Format 0_1 and/or DCI Format 0_2 include:

TCI status indication field, SRS resource set indicator, first SRI, second SRI, first TPMI field, second TPMI field

A third method of the present disclosure described below describes a procedure for a UE to transmit a PUSCH in uplink when subformats of the DCI format 0_1 and/or DCI format 0_2 described above are used.

FIG. 13 is a flowchart for explaining a case of transmitting a PUSCH based on reception of control information according to the third method of the present disclosure.

The flowchart of Fig. 13 may be an operation for a case where a UE wants to transmit a PUSCH. In addition, when the operation of the UE is described in Fig. 13, the operation of the TRP corresponding thereto may be performed. For example, when the UE receives a specific DCI, the TRP may generate the corresponding DCI and transmit it to the UE, or receive the corresponding DCI from an upper node and transmit it to the UE. Conversely, when the UE transmits a specific signal, for example, a PUSCH, the TRP may receive the PUSCH. In addition, the present disclosure assumes a case where sDCI is received in an mTRP environment or an sTRP environment.

In step S1302, the UE can receive sDCI from the TRP and blind decode the received DCI. Blind decoding can be performed based on the size of the DCI and the fields included in the DCI. Then, the UE can check the decoded DCI field. At this time, since the UE intends to transmit a PUSCH, it can expect reception of DCI format 0_1 or DCI format 0_2 from the sTRP.

If the UE receives the DCI format 0_1, the actual received DCI may be one of the first option of the third subformat of the DCI format 0_1, the second option of the third subformat of the DCI format 0_1, or the second subformat of the DCI format 0_1 as described above. If the UE receives the DCI format 0_2, the actual received DCI may be one of the first option of the third subformat of the DCI format 0_2, the second option of the third subformat of the DCI format 0_2, or the fourth subformat of the DCI format 0_2 as described above.

In explaining Fig. 13, for convenience of explanation, it is assumed that DCI format 0_1 is received. However, even if DCI format 0_2 is received, the UE can perform the same operation as in the case of DCI format 0_1 described below.

In step S1304, since the UE receives the DCI format 0_1, the UE can check whether the third subformat of the DCI format 0_1 has been received. The third subformat of the DCI format 0_1 may include fields having the first option or the second option as described above. If the third subformat of the DCI format 0_1 has been received as a result of the check in step S1304, the UE can perform step S1306. On the other hand, if the received DCI format 0_1 is not the third subformat as a result of the check in step S1304, the received DCI is the fourth subformat of the DCI format 0_1. If the DCI format 0_1 has additional subformats in addition to the third subformat and the fourth subformat of the DCI format 0_1, the UE can further include a procedure for checking whether the fourth subformat of the DCI format 0_1 has been received. However, since the third method of the present disclosure describes a case where only the third subformat and the fourth subformat of DCI format 0_1 are used, the procedure for checking whether the fourth subformat of DCI format 0_1 has been received is omitted.

When proceeding to step S1306, the UE can check whether the current sTRP communication is in progress. If it is in the mTRP communication, the UE can perform DCI failure processing. This is because the UE operates in an mTRP environment, and the third subformat of the DCI format 0_1 for maintaining the current sTRP operation in sTRP is not a normal DCI. Therefore, in step S1304, the third subformat of the DCI format 0_1 is received, and if the result of the check in step S1306 is in the sTRP environment, the routine of FIG. 13 can be terminated. In other words, the UE can give up the PUSCH transmission at the PUSCH transmission time.

If the current state is in communication with sTRP as a result of the inspection at step S1306, the UE can perform step S1308.

When proceeding to step S1308, since the third subformat of DCI format 0_1 is received, the UE can transmit PUSCH to the currently communicating TRP without dynamic switching of the TRP. At this time, the UE can perform PUSCH transmission based on a TCI state (e.g., joint/DL TCI state) corresponding to or associated with the CORESET used in the control resource set (CORESET) for reception of the received DCI format 0_1 (e.g., joint/UL TCI state).

In addition, the third subformat of DCI format 0_1 can utilize the first SRI and the first TPMI fields for both the first option and the second option as described above. And the first SRI and the first TPMI fields can indicate the SRS resource precoding information and the number of layers corresponding to the TCI state indicated in the received DCI. Based on this, the UE can transmit the PUSCH.

Meanwhile, the case where the process proceeds from step S1304 to step S1310 is when the received DCI 0_1 is the 4th subformat of DCI format 0_1 as described above. In step S1310, the UE can check whether the SRS resource set field value included in the 4th subformat of DCI format 0_1 is "00". If the SRS resource set field value included in the 2nd subformat of DCI format 0_1 is "00", the UE can proceed to step S1312, and if the SRS resource set field value included in the 2nd subformat of DCI format 0_1 is not "00", the UE can proceed to step S1320.

In step S1312, the UE may transmit the PUSCH based on the first TCI state (e.g., 1 ^st joint/UL TCI state) among the TCI states indicated in the TCI state indication field in the second subformat of the received DCI format 0_1. At this time, the first TCI state may be, for example, a TCI state for the currently communicated TRP and PUSCH transmission.

When proceeding from step S1310 to step S1320, the SRS resource set field is not "00". Therefore, the UE can check whether the SRS resource set field is "01" in step S1320. If the SRS resource set field is "01", the UE can proceed to step S1322, and if the SRS resource set field is not "01", the UE can proceed to step S1324.

In step S1322, the UE can transmit the PUSCH based on the second TCI state (e.g., ^2nd joint/UL TCI state) among the TCI states indicated in the TCI state indication field in the 4th subformat of the received DCI format 0_1. At this time, the second TCI state can be, for example, a TRP other than the currently communicating TRP. In other words, TRP dynamic switching can be performed. The TRP dynamic switching procedure is described below with reference to FIGS. 9a to 9d.

As illustrated in FIG. 9b, if the TRP currently being communicated is the first TRP (910) and the TRP corresponding to the TCI state selected based on the fourth subformat of the DCI format 0_1 received in step S1322 is the second TRP (920), the UE may transmit a PUSCH to the second TRP (920) as illustrated in FIG. 9c. As another example, if the TRP currently being communicated is the first TRP (910) and the TRP corresponding to the TCI state selected based on the second subformat of the DCI format 0_1 received in step S1322 is the third TRP (930), the UE may transmit a PUSCH to the third TRP (930) as illustrated in FIG. 9d. In other words, step S1322 may be a procedure for performing a dynamic switching operation from an sTRP to another sTRP.

When proceeding from step S1320 to step S1324, the SRS resource set field is neither "00" nor "01". In other words, proceeding to step S1324 may be when the SRS resource set field has a value of "10" or "11". In step S1324, the UE may transmit a PUSCH with two TRPs corresponding to a first TCI state (e.g., 1 ^st joint/UL TCI state) and a second TCI state (e.g., 2 ^nd joint/UL TCI state) among the TCI states indicated in the TCI state indication field in the second subformat of the received DCI format 0_1. In other words, this may be a procedure in which dynamic switching of TRP is performed from sTRP operation to mTRP operation. The TRP dynamic switching procedure of step S1324 is described below with reference to FIGS. 9a to 9d.

As illustrated in FIG. 9b, if the TRP currently being communicated is the first TRP (910), and the TRP corresponding to the first TCI state (e.g., 1 ^st joint/UL TCI state) based on the second subformat of the DCI format 0_1 received in step S1324 is the first TRP (910), and the TRP corresponding to the second TCI state (e.g., 2 ^nd joint/UL TCI state) is the second TRP (920), then the UE can transmit a PUSCH to each of the first TRP (910) and the second TRP (920), as illustrated in FIG. 9a. At this time, the PUSCH transmitted to the first TRP (910) may be transmitted based on the first TCI state (e.g., 1 ^st joint/UL TCI state), and the PUSCH transmitted to the second TRP (920) may be transmitted based on the second TCI state (e.g., 2 ^nd joint/UL TCI state).

In explaining the third method of the present disclosure, it is explained as an example that the case where the SRS resource set indicator is "10" or "11" is interpreted in the same way. However, if the SRS resource set indicator is "11", the UE does not expect to receive "11" if it is reserved.

Meanwhile, the overall operation described above has been mainly described for the case where sTRP is maintained in a state where it is switched from mTRP to sTRP, or where dynamic switching of TRP to another sTRP is performed, or where dynamic switching of TRP from sTRP to mTRP is performed. However, the operation of Fig. 13 can be applied in the same form even in the mTRP state. Hereinafter, the case where the operation of Fig. 13, which is the third method of the present disclosure, is performed in the mTRP state will be described.

In step S1302, the UE communicates in an mTRP environment, can receive sDCI from a specific TRP, and can blind decode the sDCI. Then, the UE can check the decoded sDCI. Since this is also a case where PUSCH transmission is intended, the UE can expect reception of DCI format 0_1 or DCI format 0_2. The operation below will be examined assuming that DCI format 0_1 is received as described above.

In step S1304, the UE can check whether the third subformat of DCI format 0_1 has been received. If the first subformat of DCI format 0_1 has been received as a result of the check in step S1304, the UE can perform DCI failure processing in step S1306 if it is an mTRP environment.

If the result of the inspection in step S1304 is not the first subformat of the DCI format 0_1, the process may proceed to step S1310. The subsequent procedures may be performed in the same manner as described above. For example, if the SRS resource set field is "00" (proceed to "Yes" in step S1310), the UE may transmit a PUSCH based on a first TCI state (e.g., 1 ^st joint/UL TCI state) among the TCI states indicated in the TCI state indication field in the second subformat of the first DCI format 0_1 in step S1312. At this time, the first TCI state may be any one of the TRPs communicating in the mTRP environment. For example, the first TCI state may be a TRP that transmitted sDCI.

If the SRS resource set field is not "00", in step S1320, the UE may check whether the SRS resource set field is "01". If the SRS resource set is "01", the UE may transmit the PUSCH based on the second TCI state (e.g., ^2nd joint/UL TCI state) among the TCI states indicated in the TCI state indication field in the second subformat of the received DCI format 0_1. In this case, the second TCI state may also be any one of the TRPs communicating in the mTRP environment. For example, the second TCI state may be another TRP communicating rather than the TRP that transmitted the sDCI.

If the SRS Resource Set field is neither "00" nor "01", in step S1324, the UE may transmit PUSCH with two TRPs corresponding to the first TCI state (e.g., 1 ^st joint/UL TCI state) and the second TCI state (e.g., 2 ^nd joint/UL TCI state) among the TCI states indicated in the TCI State Indication field in the 4th subformat of the received DCI format 0_1.

(2) When switching from mTRP to sTRP and then switching to sTRP is not possible

In the method described above, we have examined the case where switching from mTRP to sTRP and then switching from sTRP to another sTRP is possible. However, there may also be cases where switching from mTRP to sTRP and then switching from sTRP to another sTRP is not possible. The following describes the case where switching from mTRP to sTRP and then switching from sTRP to another sTRP is not possible. In addition, the present disclosure describes the operation when the UE transmits a PUSCH.

[Method 4]

As described above, the 3GPP standard stipulates that the SRS resource set indicator can be set to 0 bits or 2 bits. Therefore, the present disclosure assumes a case where the SRS resource set indicator is set to 2 bits in the DCI. When the SRS resource set indicator is set to 2 bits, the SRS resource set indicator can be set to one of four values: "00", "01", "10", or "11". In the fourth method of the present disclosure, it is assumed that the SRS resource set indicator indicates the following operation.

1) SRS resource set indicator "00" indicates the use of the first TCI state (e.g., 1 ^st joint/UL TCI state) indicated in the received DCI.

2) SRS resource set indicator “01” indicates the use of the second TCI state (e.g., ^2nd joint/UL TCI state) among the TCI states indicated in the received DCI.

3) SRS resource set indicator "10" and/or "11" indicates that the first TCI state (e.g., 1 ^st joint/UL TCI state) and the second TCI state (e.g., 2 ^nd joint/UL TCI state) indicated in the DCI are used together. In other words, SRS resource set indicator "10" and/or "11" can be applied only when the operation is mTRP and not sTRP. If SRS resource set indicator "11" is reserved, SRS resource set indicator "11" is not defined and the UE does not expect to receive SRS resource set indicator "11".

The DCI according to the fourth method of the present disclosure may include the following fields:

TCI status indication field, SRS resource set indication field, first SRI field, second SRI field, first TPMI field, second TPMI field

Among the above fields, fields that are not currently supported by the 3GPP standard can be inferred as newly added to the DCI or as using the most recently valid DCI field among the previously received DCI fields. Since the present disclosure is for a case where a UE intends to transmit a PUSCH, the DCI exemplified above may be DCI format 0_1 and/or DCI format 0_2. According to the current 3GPP standard, the DCI format 0_1 and/or DCI format 0_2 does not define a TCI status indication field. Therefore, if the current 3GPP standard specification is used as it is, the TCI status indication field may use the TCI status indication field included in any one of DCI format 1_1, DCI format 1_2, or DCI format 1_3 including the most recently received downlink control information.

FIG. 14 is a flowchart for explaining a case of transmitting a PUSCH based on reception of control information according to the fourth method of the present disclosure.

Before explaining the operation of FIG. 14, the fourth method of the present disclosure is an embodiment for a case where switching from mTRP to sTRP is supported, and switching from sTRP to mTRP is supported. However, it may be an operation for a case where switching from sTRP to another sTRP is not supported after switching from mTRP to sTRP. In addition, the present disclosure described below is an embodiment for a case where a UE wants to transmit a PUSCH.

At step S1400, the UE may be connected to sTRP. In other words, as described above, the UE may be in a state of communicating with sTRP after switching from mTRP to sTRP.

In step S1402, the UE can receive DCI from the connected TRP and blind decode the received DCI. Then, the UE can check the decoded DCI field. The blind decoding can be performed based on the size of the DCI and the fields included in the DCI. At this time, since the UE wants to transmit a PUSCH, it can expect to receive DCI format 0_1 or DCI format 0_2 from the sTRP. The DCI format 0_1 or DCI format 0_2 can be inferred from other DCI if it includes or does not include the fields described above.

Since the embodiment of Fig. 14 is a flowchart for PUSCH transmission, a case in which a DCI other than DCI for controlling uplink transmission, such as DCI format 0_1 or DCI format 0_2, is received is not considered.

In step S1404, the UE can check whether the sTRP operation maintenance is indicated based on the SRS resource set indicator among the fields included in DCI format 0_1 or DCI format 0_2. In other words, it can check whether the SRS resource set indicator codepoint described above indicates the sTRP operation maintenance. Whether the SRS resource set indicator codepoint indicates the sTRP operation maintenance may vary depending on the setting value of a previously received RRC message.

For example, if the configuration value of the RRC message indicates the use of the first TCI state (e.g., 1 ^st joint/UL TCI state), and the code point of the SRS resource set indicator is "00" indicating the first TCI state, it may be interpreted as indicating sTRP operation maintenance. However, if the configuration value of the RRC message indicates the use of the first TCI state, but the code point of the SRS resource set indicator is "01" indicating the second TCI state (e.g., 2 ^nd joint/UL TCI state), it may be interpreted as indicating sTRP switching. Therefore, this case may not be a case of sTRP operation maintenance.

As another example, if the configuration value of the RRC message indicates the use of the second TCI state (e.g., 2 ^nd joint/UL TCI state), and the code point of the SRS resource set indicator is "00" indicating the first TCI state, it can be interpreted as indicating sTRP switching. On the other hand, if the configuration value of the RRC message indicates the use of the second TCI state and the code point of the SRS resource set indicator is "01" indicating the second TCI state (e.g., 2 ^nd joint/UL TCI state), it can be interpreted as indicating maintaining the sTRP operation.

If the inspection result of step S1404 indicates that the sTRP operation should be maintained, the UE may proceed to step S1406 to transmit a PUSCH to the corresponding TRP based on the DCI indication. At this time, the UE may perform the mTRP operation in a manner indicated by the TCI status indication field, the SRS resource set indicator field, and the SRI corresponding to the TCI among the two SRIs and the TPMI corresponding to the TCI among the two TPMI fields included in the received DCI format 0_1 or the received DCI format 0_2.

On the other hand, if the inspection result of step S1404 does not instruct maintenance of sTRP operation, the UE can proceed to step S1410.

In step S1410, the UE can check whether switching to mTRP is indicated based on the SRS resource set indicator among the fields included in the DCI format 0_1 or the DCI format 0_2. In other words, it can check whether the SRS resource set indicator codepoint described above indicates switching to mTRP. The case where the SRS resource set indicator codepoint indicates switching to mTRP may be when the SRS resource set indicator is "10" and/or "11". In other words, it may be the case where the first TCI state (e.g., 1 ^st joint/UL TCI state) and the second TCI state (e.g., 2 ^nd joint/UL TCI state) are indicated to be used together within the received DCI format 0_1 or the DCI format 0_2.

If the inspection result of step S1410 indicates that switching to mTRP is instructed, the UE can perform step S1412, and if the inspection result of step S1410 indicates that switching to mTRP is not instructed, the UE can perform step S1430.

First, let's look at the case where step S1430 is performed. Step S1430 is performed when the result of the inspection in step S1406 is not sTRP maintenance, and the result of the inspection in step S1410 is not an instruction to switch to mTRP. Therefore, the case where step S1430 is performed may correspond to the case where switching to sTRP is instructed. However, the fourth method of the present disclosure may support TRP switching from mTRP to sTRP and TRP switching from sTRP to mTRP, but not switching from sTRP to sTRP. Therefore, a UE that needs to transmit a PUSCH may perform step S1430 or omit PUSCH transmission.

In step S1430, the UE can operate according to one of two options. If according to the first option, in step S1430, the UE can transmit the PUSCH to the currently communicated TRP by applying a TCI state corresponding to the RRC configuration. If according to the second option, in step S1430, the UE can apply an indication of the DCI format 0_1 or DCI format 0_2 received immediately before instead of using the currently received and decoded DCI format 0_1 or DCI format 0_2. If the UE does not use the DCI format 0_1 or DCI format 0_2 received immediately before, the UE can also use a TCI state set to the DCI format 1_1, DCI format 1_2, or DCI format 1_3 received immediately for downlink control.

Thereafter, the UE may proceed to step S1406 and transmit a PUSCH with the corresponding sTRP based on the indicated information, for example, the indicated information set in the RRC message or set by the previous DCI.

Next, if the inspection result of step S1410 indicates that DCI format 0_1 or DCI format 0_2 is TRP switching to mTRP, and the process proceeds to step S1412, the UE can switch to mTRP. For example, as described above in FIG. 9b, this may be the case when the UE is communicating with the first TRP (910) and is simultaneously connected to the first TRP (910) and the second TRP (920) as shown in FIG. 9a. As another example, as described in FIG. 9c, this may be the case when the UE is communicating with the second TRP (290) and is simultaneously connected to the first TRP (910) and the second TRP (920) as shown in FIG. 9a.

The UE, which performs TRP switching from sTRP to mTRP in step S1412, can transmit PUSCH to multiple connected TRPs. And in step S1414, the UE can maintain the mTRP state. At this time, the UE can perform the mTRP operation in a manner indicated by the TCI status indication field, the SRS resource set indicator field, two SRIs, and two TPMI fields included in the received DCI format 0_1 or the received DCI format 0_2.

After that, the UE can receive DCI from one of the mTRPs in step S1416. And the UE can blind decode the received DCI. The blind decoding can be performed based on the size of the DCI and the fields included in the DCI as described above. And the UE can check the decoded DCI field.

In step S1418, the UE can check whether switching to sTRP is indicated based on the received DCI, for example, the received DCI format 0_1 or the received DCI format 0_2. The check in step S1418 may be a procedure for checking whether the code point of the SRS resource set indicator included in the DCI format 0_1 or the DCI format 0_2 indicates TRP switching to sTRP, as discussed above. In other words, it can be checked whether the SRS resource set indicator is "00" or "01". If the SRS resource set indicator included in the DCI format 0_1 or the DCI format 0_2 indicates TRP switching to sTRP, the process can proceed to step S1420.

If the SRS resource set indicator included in DCI format 0_1 or DCI format 0_2 does not indicate TRP switching to sTRP, it means that the mTRP environment is maintained, and therefore the UE can proceed to step S1414.

In step S1420, the UE may perform TRP switching to sTRP based on information of the SRS resource set indicator included in DCI format 0_1 or DCI format 0_2, and then transmit PUSCH to the connected sTRP. Then, the UE may proceed to step S1400.

[Method 5]

The fifth method according to the present disclosure described below is an embodiment for a case where switching from mTRP to sTRP and then switching from sTRP to another sTRP is impossible, and two methods are largely presented. First, the fifth method according to the present disclosure is a case where the first subformat and the second subformat for DCI format 0_1 or DCI format 0_2 are utilized as described in the second method above. Second, the fifth method according to the present disclosure is a case where the third subformat and the fourth subformat for DCI format 0_1 or DCI format 0_2 are utilized as described in the third method above.

<Example of utilizing the first subformat and the second subformat for DCI format 0_1 or DCI format 0_2>

An embodiment utilizing the first subformat and the second subformat for DCI format 0_1 or DCI format 0_2 may operate as described above in FIG. 12, except that it may not support TRP switching from sTRP to another sTRP.

When a UE performing sTRP operation receives DCI of the first subformat among two subformats, the sTRP operation can be maintained without TRP switching. In other words, the UE can maintain the current sTRP when it receives any one of Option 1 of the first subformat of DCI format 0_1, Option 2 of the first subformat of DCI format 0_1, Option 1 of the first subformat of DCI format 0_2, or Option 2 of the first subformat of DCI format 0_2. And the UE can transmit PUSCH with the current sTRP. At this time, the indication of the TCI state used for PUSCH transmission can be based on the configuration of an RRC message preset for DCI reception among the TCI states of the received DCI.

For example, if the RRC message sets the first TCI state for DCI reception, the UE can use the first TCI state among the first TCI state (e.g., 1 ^st join/UL TCI state) and the second TCI state (e.g., 2 ^nd join/UL TCI state) included in the received DCI for PUSCH transmission. On the other hand, if the RRC message sets the second TCI state for DCI reception, the UE can use the second TCI state among the first TCI state (e.g., 1 ^st join/UL TCI state) and the second TCI state (e.g., 2 ^nd join/UL TCI state) included in the received DCI for PUSCH transmission.

Additionally, the first SRI and TPMI fields included in the received DCI can indicate SRS resources, precoding information, and number of layers corresponding to the corresponding TCI state.

Meanwhile, if a UE performing sTRP operation receives DCI of the second subformat among the two subformats, the UE may maintain the sTRP operation without TRP switching or perform TRP switching to mTRP. In other words, if the UE receives either the second subformat of DCI format 0_1 or the second subformat of DCI format 0_2, the UE may maintain the current sTRP or perform TRP switching to mTRP.

As described in the second method above, if the configuration value of the RRC configured for receiving DCI indicates the use of the first TCI state, the UE can expect a state in which the SRS resource set indicator included in the received DCI includes '00' or '10' or '11'. As another example, if the configuration value of the RRC configured for receiving DCI indicates the use of the second TCI state, the UE can expect a state in which the SRS resource set indicator includes '01' or '10' or '11'.

As described in the second method, if the SRS resource set indicator is '00', it indicates the use of the first TCI state (e.g., 1 ^st joint/UL TCI state) among the TCI states included in the DCI, and if the SRS resource set indicator is '01', it indicates the use of the second TCI state (e.g., 2 ^nd joint/UL TCI state) among the TCI states included in the DCI, and if the SRS resource set indicator is '10' or '11', it may be an mTRP operation rather than an sTRP operation. As described in the second method, if the SRS resource set indicator '11' is reserved, the UE does not expect to receive '11' as the SRS resource set indicator.

Meanwhile, if the UE indicates a codepoint other than the codepoint expected by the SRS resource set indicator, the UE may ignore the indication of the codepoint and apply a TCI state (e.g., joint/UL TCI state) based on the configuration in the RRC message configured for DCI reception as described above, or maintain the configuration of the TCI state indicated in the previous DCI. Here, the previous may be the most recently received DCI format 0_1 or DCI format 0_2 among the time points preceding the current DCI as described above, or any one of the most recently received DCI format 1_1, DCI format DCI format 1_1, or DCI format 1_2 among the time points preceding the current DCI.

Meanwhile, when a UE communicating in an mTRP environment wants to perform PUSCH transmission, the UE may expect reception of the second subformat for DCI format 0_1 or DCI format 0_2. Therefore, the UE may attempt blind decoding based on the received DCI size and field definitions at the time of decoding attempt. And the UE may perform sTRP or mTRP operation in a manner indicated by the TCI status indication field, the SRS resource set indication field, the first SRI, the second SRI, the first TPMI field, and the second TPMI field included in the decoded DCI.

For example, if the SRS resource set indicator field in the received DCI is '00', the UE can transmit the PUSCH based on the first TCI state (e.g., 1 ^st joint/UL TCI state) among the TCI states indicated by the field indicating the TCI state in the corresponding DCI (Example 1 of sTRP transmission). As another example, if the SRS resource set indicator field in the received DCI is '01', the UE can transmit the PUSCH based on the second TCI state (e.g., 2 ^nd joint/UL TCI state) among the TCI states indicated by the field indicating the TCI state in the corresponding DCI (Example 2 of sTRP transmission).

As another example, if the SRS resource set indicator is '10' or '11', the UE can transmit PUSCH with two TRPs based on the first TCI state (e.g., 1 ^st joint/UL TCI state) and the second TCI state (e.g., 2 ^nd joint/UL TCI state).

As described in the second method, if the SRS resource set indicator '11' is reserved, the UE does not expect to receive DCI with the SRS resource set indicator set to '11'.

<Example of the third sub-format for DCI format 0_1 or DCI format 0_2 and the case of utilizing the third sub-format>

An embodiment utilizing the third subformat and the fourth subformat for DCI format 0_1 or DCI format 0_2 may operate as described above in FIG. 13, except that TRP switching from sTRP to another sTRP may not be supported.

If a UE performing sTRP operation receives DCI of the third subformat among the two subformats, the sTRP operation can be maintained without TRP switching. In other words, the UE can maintain the current sTRP if it receives any one of Option 1 of the third subformat of DCI format 0_1, Option 2 of the third subformat of DCI format 0_1, Option 1 of the third subformat of DCI format 0_2, or Option 2 of the third subformat of DCI format 0_2. And the UE can transmit PUSCH with the current sTRP. At this time, a TCI state used for PUSCH transmission can use a TCI state corresponding to a TCI state used in CORESET for DCI reception (e.g., joint/DL TCI state) or a TCI state associated with a TCI state used in CORESET.

The third subformat of DCI format 0_1 can utilize the first SRI and the first TPMI fields for both the first option and the second option as described above. And the first SRI and the first TPMI fields can indicate the SRS resource precoding information and the number of layers corresponding to the TCI state indicated in the received DCI. Based on this, the UE can transmit the PUSCH.

Meanwhile, if a UE performing sTRP operation receives DCI of subformat 4 among two subformats, that is, if the UE receives either DCI format 0_1 of the fourth subformat or DCI format 0_2 of the fourth subformat, the sTRP operation can be maintained without TRP switching, or switched to mTRP operation.

For example, if the configuration value of an RRC message configured for receiving DCI indicates the 1st TCI state, the UE may expect the SRS resource set indicator in the received DCI to be '00' or '10' or '11'. As another example, if the configuration value of an RRC message configured for receiving DCI indicates the 2nd TCI state (e.g., 2nd TCI state), the UE may expect the SRS resource set indicator in the received DCI to be '01' or '10' or '11'.

As described in the third method, when the SRS resource set indicator is '00', it indicates the first TCI state (e.g., 1 ^st joint/UL TCI state) among the TCI states in the received DCI.

If the SRS resource set indicator is '01', it indicates the second TCI state (e.g., ^2nd joint/UL TCI state) among the TCI states indicated in the DCI among the TCI states in the received DCI, and if the SRS resource set indicator is '10' or '11', it indicates an mTRP operation, not an sTRP operation, and both the first TCI state (e.g., ^1st joint/UL TCI state) and the second TCI state (e.g., ^2nd joint/UL TCI state) in the received DCI may be used. In this case, if the SRS resource set indicator is '11' reserved, the UE does not expect to receive DCI with the SRS resource set indicator set to '11'.

In addition, if the SRS resource set indicator indicates a code point other than the expected code point, the indication of the code point may be ignored, and the TCI state corresponding to the RRC setting set for DCI reception (e.g., joint/UL TCI state) may be applied as described in the third method, or the setting of the TCI state indicated in the previous DCI may be maintained.

On the other hand, a UE performing an mTRP operation expects reception of the 4th subformat of DCI format 0_1 or the 4th subformat of DCI format 0_1. Therefore, the UE can perform blind decoding according to the DCI size and field definition when coding the received DCI. And the UE can perform the sTRP or mTRP operation in a manner indicated by the TCI status indication field, the SRS resource set indication field, the first SRI, the second SRI, the first TPMI field and the second TPMI field in the corresponding DCI.

As described in the third method above, the UE can determine the TCI state based on the SRS resource set indicator included in the received DCI.

For example, a UE that has received a DCI of the 4th subformat of DCI format 0_1 or the 4th subformat of DCI format 0_1 may transmit a PUSCH based on the first TCI state (e.g., 1 ^st joint/UL TCI state) among the TCI states within the corresponding DCI if the SRS resource set indicator field is '00'.

As another example, a UE that receives a DCI of the 4th subformat of DCI format 0_1 or the 4th subformat of DCI format 0_1 may transmit a PUSCH based on the second TCI state (e.g., 2 ^nd joint/UL TCI state) among the TCI states within the corresponding DCI if the SRS Resource Set Indicator field is '01'.

As another example, a UE that receives a DCI of the 4th subformat of DCI format 0_1 or a DCI of the 4th subformat of DCI format 0_1, if the SRS Resource Set Indicator field is '10' or '11', the UE can transmit PUSCHs to the respective TRPs based on the first TCI state (e.g., 1 ^st joint/UL TCI state) and the second TCI state (e.g., 2 ^nd joint/UL TCI state) within the corresponding DCI.

At this time, if the SRS resource set indicator '11' is reserved as described in the third method, the UE does not expect to receive '11' as the SRS resource set indicator.

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)

In a method of user equipment (UE), A step of receiving first downlink control information (DCI) from a first transmission and reception point (TRP); A step of confirming whether switching between single TRPs (sTRPs) is supported when the received first DCI is in a format indicating uplink (UL) transmission and a first field included in the first DCI indicates UL transmission with a second TRP; A step of performing TRP switching from the first TRP to the second TRP supporting switching between the above sTRPs; and A step of transmitting a physical uplink shared channel (PUSCH) based on a transmission configuration indication (TCI) status corresponding to the second TRP, UE's method. In claim 1, The above first DCI further includes a TCI state indication field indicating a first TCI state (1 ^st joint/UL TCI state) and a second TCI state (2 ^nd joint/UL TCI state) for UL transmission, The second PUSCH transmitted to the second TRP is transmitted based on either the first TCI state or the second TCI state. UE's method. In claim 1, The above TCI status is determined by the TCI status indication field included in the second DCI most recently received among the DCIs for downlink (DL) transmission received before the reception of the first DCI. UE's method. In claim 3, The above TCI state indication field further includes a first TCI state (1 ^st joint/UL TCI state) and a second TCI state (2 ^nd joint/UL TCI state) for UL transmission. UE's method. In claim 1, Further comprising a step of transmitting the PUSCH to the first TRP based on a TCI state for UL transmission included in a radio resource control (RRC) message for receiving the first DCI when the first field indicates UL transmission to the second TRP and switching between the sTRPs is not supported. UE's method. In claim 1, Further comprising a step of transmitting the PUSCH to the first TRP based on a TCI state for UL transmission included in a second DCI most recently received among DCIs received before receiving the first DCI, when the first field indicates UL transmission to the second TRP and switching between the sTRPs is not supported. UE's method. In claim 1, The method further comprises the step of transmitting physical uplink shared channels (PUSCHs) to each of the first TRP and the second TRP based on TCI states corresponding to each of the first TRP and the second TRP, when the received first DCI is in a format indicating uplink (UL) transmission and the first field indicates UL transmission to both the first TRP and the second TRP. UE's method. In claim 7, The first TCI state corresponding to the first TRP is either a first TCI state (1 ^st joint/UL TCI state) or a second TCI state (2 ^nd joint/UL TCI state) included in the first DCI, and The second TCI state corresponding to the second TRP is a TCI state different from the TCI state applied to the first TRP among the first TCI state or the second TCI state. UE's method. In claim 7, The first TCI state corresponding to the first TRP is either a first TCI state (1 ^st joint/UL TCI state) or a second TCI state (2 ^nd joint/UL TCI state) included in the most recently received second DCI among the DCIs received before receiving the first DCI, and The second TCI state corresponding to the second TRP is a TCI state different from the TCI state applied to the first TRP among the first TCI state or the second TCI state. UE's method. In claim 1, The above first field is a sounding reference signal (SRS) resource set indicator field consisting of 2 bits, If the 2 bits of the above SRS resource indicator set indicate "00", the PUSCH transmission is indicated with the currently communicating TRP, If the 2 bits of the above SRS resource indicator set indicate "01", the PUSCH transmission is indicated with the second TRP, and The two bits of the above SRS resource indicator set, either “10” or “11”, indicate transmission of the PUSCHs with the first TRP and the second TRP. UE's method. In user equipment (UE), comprising at least one processor, wherein said at least one processor comprises: Receive first downlink control information (DCI) from a first transmission and reception point (TRP); If the received first DCI is in a format indicating uplink (UL) transmission and the first field included in the first DCI indicates UL transmission with a second TRP, it is confirmed whether switching between single TRPs (sTRPs) is supported; Performing TRP switching from the first TRP to the second TRP supporting switching between the above sTRPs; and Causing to transmit a physical uplink shared channel (PUSCH) based on a transmission configuration indication (TCI) status corresponding to the second TRP. UE. In claim 11, The above first DCI further includes a TCI state indication field indicating a first TCI state (1 ^st joint/UL TCI state) and a second TCI state (2 ^nd joint/UL TCI state) for UL transmission, The second PUSCH transmitted to the second TRP is transmitted based on either the first TCI state or the second TCI state. UE. In claim 11, The above TCI status is determined by the TCI status indication field included in the second DCI most recently received among the DCIs for downlink (DL) transmission received before the reception of the first DCI. UE. In claim 13, The above TCI state indication field further includes a first TCI state (1 ^st joint/UL TCI state) and a second TCI state (2 ^nd joint/UL TCI state) for UL transmission. UE. In claim 11, At least one processor of the UE: Further causing the PUSCH to be transmitted to the first TRP based on a TCI state for UL transmission included in a radio resource control (RRC) message for receiving the first DCI if the first field indicates UL transmission to the second TRP and switching between the sTRPs is not supported. UE. In claim 11, At least one processor of the UE: Further causing the PUSCH to be transmitted with the first TRP based on a TCI state for UL transmission included in a second DCI most recently received among DCIs received before receiving the first DCI, if the first field indicates UL transmission with the second TRP and switching between the sTRPs is not supported. UE. In claim 11, At least one processor of the UE: If the received first DCI is in a format indicating uplink (UL) transmission, and the first field indicates UL transmission to both the first TRP and the second TRP, further causing physical uplink shared channels (PUSCHs) to be transmitted to each of the first TRP and the second TRP based on TCI states corresponding to each of the first TRP and the second TRP, UE. In claim 17, The first TCI state corresponding to the first TRP is either a first TCI state (1 ^st joint/UL TCI state) or a second TCI state (2 ^nd joint/UL TCI state) included in the first DCI, and The second TCI state corresponding to the second TRP is a TCI state different from the TCI state applied to the first TRP among the first TCI state or the second TCI state. UE. In claim 17, The first TCI state corresponding to the first TRP is either a first TCI state (1 ^st joint/UL TCI state) or a second TCI state (2 ^nd joint/UL TCI state) included in the most recently received second DCI among the DCIs received before receiving the first DCI, and The second TCI state corresponding to the second TRP is a TCI state different from the TCI state applied to the first TRP among the first TCI state or the second TCI state. UE. In claim 11, The above first field is a sounding reference signal (SRS) resource set indicator field consisting of 2 bits, If the 2 bits of the above SRS resource indicator set indicate "00", the PUSCH transmission is indicated with the currently communicating TRP, If the 2 bits of the above SRS resource indicator set indicate "01", the PUSCH transmission is indicated with the second TRP, and The two bits of the above SRS resource indicator set, either “10” or “11”, indicate transmission of the PUSCHs with the first TRP and the second TRP. UE.

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