Method and device for transmitting signal in asymmetric multi-transmission / reception point scenario

Abstract

A method performed by a UE according to an embodiment of the present disclosure may comprise the steps of: receiving, from a first TRP, a first message indicating to transmit a first UL signal to the first TRP or a second TRP in an RRC-connected state with the first TRP; generating the first UL signal on the basis of the received first message; and transmitting the generated first UL signal to the second TRP when the received first message indicates transmission to the second TRP, wherein the second TRP may be controlled by the first TRP.

Description

Method and device for transmitting signals in an asymmetric multi-transmission / reception point scenario

[0001] The present disclosure relates to signal transmission technology, and more particularly, to signal transmission technology in an asymmetric multiple transmission / reception point scenario.

[0002] With the advancement of information and communication technology, various wireless communication technologies are being developed. Representative wireless communication technologies include LTE (long term evolution) and NR (new radio), both of which are defined by the 3rd generation partnership project (3GPP) standards. LTE can be one of the 4th generation (4G) wireless communication technologies, and NR can be one of the 5th generation (5G) wireless communication technologies.

[0003] To handle the rapidly increasing amount of wireless data following the commercialization of 4G communication systems (e.g., communication systems supporting LTE), 5G communication systems (e.g., communication systems supporting NR) that use higher frequency bands (e.g., frequency bands higher than 6 GHz) than the frequency bands of 4G communication systems (e.g., frequency bands below 6 GHz) are being considered. 5G communication systems can support enhanced Mobile Broadband (eMBB), Ultra-Reliable and Low Latency Communication (URLLC), and massive Machine Type Communication (mMTC).

[0004] Meanwhile, wireless communication systems provide a method for communicating with terminals using Transmission and Reception Points (TRPs) to expand the coverage of base stations. In this case, a user equipment (UE) may be able to communicate with multiple TRPs (mTRPs). In other words, the UE can transmit and receive signals with the mTRPs on the downlink (DL) and / or uplink (UL). Each mTRP may be installed in a different geographical location and have different coverage. In an asymmetric mTRP scenario where mTRPs have different coverage, a method may be required for the UE to communicate with one or more TRPs.

[0005] The purpose of the present disclosure to address the above needs is to provide a procedure, method and apparatus for a UE to communicate with one or more TRPs in an asymmetric mTRP scenario.

[0006] According to one embodiment of the disclosure for achieving the above object, a method of a user equipment (UE) may include the steps of: receiving a first message instructing to transmit a first uplink (UL) signal from a first Transmission and Reception Point (TRP) to a first TRP or a second TRP in a radio resource control (RRC) connected state; generating the first UL signal based on the received first message; and transmitting the generated first UL signal to the second TRP when the received first message instructs transmission to the second TRP.

[0007] The above second TRP may be a TRP controlled by the above first TRP.

[0008] The above first UL signal may be a random access (RA) preamble transmitted through a physical random access channel (PRACH).

[0009] The first message may be downlink control information (DCI) used for physical downlink control information (PDCCH)-order, and the DCI may include a first field indicating whether a path loss (PL) offset is included and the PL offset included when determining the transmission power of the first UL signal.

[0010] The first field may be present when a first parameter included in an RRC message received from the first TRP indicates activation of the first field, and an indicated transmission configuration indication (TCI) state is configured that configures one or more of the PL offsets within the RRC message.

[0011] If a first parameter of an RRC message received from the first TRP before reception of the first message indicates activation of the first field included in the DCI, and a transmission configuration indication (TCI) of the RRC message or a Media Access Control-Control element (MAC CE) message received from the first TRP before reception of the first message indicates one joint / UL TCI state constituting the PL offset, the first field may indicate whether the PL offset of the one joint / UL TCI state is included in calculation of transmission power of the first UL signal transmitted to the second TRP.

[0012] The method may further include receiving an RRC message or a Media Access Control-Control element (MAC CE) message from the first TRP before receiving the first message,

[0013] If the transmission configuration indication (TCI) of the RRC message or the MAC CE message indicates two joint / UL TCI states that constitute the PL offset, the first field may indicate that the PL offset configured in one of the two indicated joint / UL TCI states is included in the calculation of the transmission power of the second UL signal transmitted to the second TRP.

[0014] If a first parameter of an RRC message received from the first TRP prior to reception of the first message indicates activation of the first field included in the DCI, and the RRC message is configured with two indicated joint / UL transmission configuration indication (TCI) states for the serving cell together with the PL offset, the first field may indicate transmission of the first UL signal in one of the two joint / UL TCI states.

[0015] If the first field is instructed to apply the PL offset to a transmission configuration indication (TCI) state or UL TCI state specified by a higher layer, the first PL offset to be applied to the first UL signal power calculation may be instructed to use the difference between the PL offset and the PL value related to the first UL signal transmission in the active downlink (DL) bandwidth part (BWP) from the first TRP.

[0016] According to one embodiment of the disclosure for achieving the above object, a method of a first transmission and reception point (TRP) may include the steps of: transmitting a first message instructing a user equipment (UE) in a radio resource control (RRC) connected state to transmit a first uplink (UL) signal to one or more second TRPs; receiving first information related to the first message from the one or more second TRPs; and transmitting a second message instructing the one or more second TRPs to transmit a second UL signal based on the first information.

[0017] The above second TRP may be a TRP controlled by the above first TRP.

[0018] The above first UL signal may be a random access (RA) preamble transmitted through a physical random access channel (PRACH).

[0019] The above first message may be downlink control information (DCI) used for physical downlink control information (PDCCH)-order,

[0020] The DCI may include a first field indicating whether a path loss (PL) offset is included and the PL offset included when determining the transmission power of the first UL signal.

[0021] It may further include a step of transmitting an RRC message transmitted to the UE before transmitting the first message,

[0022] The first field may be included in the DCI when a first parameter included in the RRC message indicates activation of the first field, and a transmission configuration indication (TCI) state that configures one or more of the PL offsets is configured in the RRC message.

[0023] It may further include a step of transmitting an RRC message or a Media Access Control-Control element (MAC CE) message to the UE before transmitting the first message,

[0024] If the transmission configuration indication (TCI) of the RRC message or the MAC CE message indicates two joint / UL TCI states that constitute the PL offset, the first field may indicate that the PL offset configured in one of the two indicated joint / UL TCI states is to be included in the calculation of the transmission power of the second UL signal transmitted to the second TRP.

[0025] It may further include a step of transmitting an RRC message and a Media Access Control-Control element (MAC CE) message to the UE before transmitting the first message,

[0026] If a first parameter of the RRC message indicates activation of the first field included in the DCI, and a transmission configuration indication (TCI) of a Media Access Control-Control element (MAC CE) message received before receiving the first message from the RRC message or the first TRP indicates one joint / UL TCI state constituting the PL offset, the first field may indicate whether the PL offset of the one joint / UL TCI state is included in calculation of transmission power of the first UL signal transmitted to the second TRP.

[0027] It may further include a step of transmitting an RRC message to the UE before transmitting the first message,

[0028] If a first parameter of the RRC message indicates activation of the first field included in the DCI, and the RRC message is configured with two indicated joint / UL transmission configuration indication (TCI) states for the serving cell together with the PL offset, the first field may indicate transmission of the first UL signal in one of the two joint / UL TCI states.

[0029] If the first field is instructed to apply the PL offset to a transmission configuration indication (TCI) state or UL TCI state specified by a higher layer, the first PL offset to be applied to the first UL signal power calculation may be instructed to use the difference between the PL offset and the PL value related to the first UL signal transmission in the active downlink (DL) bandwidth part (BWP) from the first TRP.

[0030] According to one embodiment of the disclosure for achieving the above purpose, a user equipment (UE) includes at least one processor, wherein the at least one processor comprises:

[0031] A first transmission and reception point (TRP) and a radio resource control (RRC) connected state receive a first message from the first TRP instructing to transmit a first uplink (UL) signal to the first TRP or a second TRP; generate the first UL signal based on the received first message; and cause the generated first UL signal to be transmitted to the second TRP when the received first message instructs transmission to the second TRP.

[0032] The above second TRP may be a TRP controlled by the above first TRP.

[0033] The above first UL signal may be a random access (RA) preamble transmitted through a physical random access channel (PRACH).

[0034] The above first message may be downlink control information (DCI) used for physical downlink control information (PDCCH)-order,

[0035] The DCI may include a first field indicating whether a path loss (PL) offset is included and the PL offset included when determining the transmission power of the first UL signal.

[0036] The first field may be present when a first parameter included in an RRC message received from the first TRP indicates activation of the first field, and an indicated transmission configuration indication (TCI) state is configured that configures one or more of the PL offsets within the RRC message.

[0037] According to one embodiment of the present disclosure, a transmission / reception procedure capable of maximizing uplink capacity in an asymmetric mTRP deployment scenario can be provided. In particular, in an asymmetric mTRP deployment scenario, the UL transmission power and the direction of the UL transmission beam to a UL-only TRP can be determined by considering the mobility of the UE. Furthermore, according to one embodiment of the present disclosure, since the first TRP can instruct the UE on an appropriate UL transmission power, the problem of interference with adjacent cells caused by excessive UL transmission power to the UL-only TRP can be resolved. In addition, the problem of UL desynchronization with an unknown UL-only TRP can be resolved. Therefore, in an asymmetric mTRP deployment scenario, the UE can transmit a UL signal (or data) to an unknown UL-only TRP at an appropriate power, thereby providing the advantage of faster data transmission and reduced power consumption of the UE.

[0038] Figure 1 is a conceptual diagram illustrating one embodiment of a communication system.

[0039] Figure 2 is a block diagram illustrating one embodiment of a communication node constituting a communication system.

[0040] Figure 3a is a concept for explaining signal transmission between intra-cell multiple TRPs and UE.

[0041] Figure 3b is a conceptual diagram for explaining signal transmission between inter-cell multiple TRPs and UEs.

[0042] Figure 4 is a conceptual diagram illustrating signal transmission between a TRP and a UE in an asymmetric mTRP scenario.

[0043] Figure 5 is a conceptual diagram illustrating the first scenario in an asymmetric mTRP environment.

[0044] Figure 6 is a conceptual diagram illustrating a second scenario in an asymmetric mTRP environment.

[0045] Figure 7a is a conceptual diagram illustrating a third scenario in an asymmetric mTRP environment.

[0046] FIG. 7b is a timing diagram for explaining the transmission and reception times of signals between a UE and a TRP in a third scenario in an asymmetric mTRP environment.

[0047] Figure 8a is a conceptual diagram illustrating scenario 3-1 in an asymmetric mTRP environment.

[0048] FIG. 8b is a timing diagram for explaining the transmission and reception times of signals between a UE and a TRP at an initial location where synchronization is acquired in scenario 3-1 in an asymmetric mTRP environment.

[0049] FIG. 8c is a timing diagram for explaining the transmission and reception times of signals between a UE and a TRP when the UE moves from an initial location where synchronization was acquired in scenario 3-1 in an asymmetric mTRP environment.

[0050] Figure 9 is a timing diagram for explaining a situation in which an asynchronous problem occurs in a UL-only TRP and the minimum absolute value of the asynchronous problem.

[0051] Figure 10a is a flowchart for explaining the initial connection procedure of a UE in a third scenario in an asymmetric mTRP environment.

[0052] Figure 10b is a flowchart for explaining uplink transmission of a UE in a third scenario in an asymmetric mTRP environment.

[0053] Figure 11 is a conceptual diagram for explaining a case where UE has completed RRC setup with the first TRP in the third asymmetric mTRP scenario.

[0054] Figure 12 is a conceptual diagram for explaining a case where a UE transmits an uplink signal by beam sweeping in a third scenario in an asymmetric mTRP environment.

[0055] Figure 13 is a conceptual diagram illustrating a case where UL-only TRPs in an asymmetric mTRP environment transmit a given estimated value to the first TRP.

[0056] FIG. 14 is a conceptual diagram illustrating a case where a macro TRP in an asymmetric mTRP environment transmits mapping information calculated based on estimated values ​​received from UL-only TRPs to a UE.

[0057] Figure 15 is a conceptual diagram illustrating the relationship between PL offset settings required for uplink power control, delta PL settings, and TCI state settings.

[0058] Fig. 16 is a conceptual diagram illustrating the configuration of the first PL offset MAC CE of the seventh embodiment.

[0059] Fig. 17 is a conceptual diagram illustrating the configuration of the second PL offset MAC CE of the seventh embodiment.

[0060] Fig. 18 is a conceptual diagram illustrating the configuration of the third PL offset MAC CE of the seventh embodiment.

[0061] Fig. 19 is a conceptual diagram illustrating the configuration of the fourth PL offset MAC CE of the seventh embodiment.

[0062] Figure 20 is a conceptual diagram for explaining a case in which UL communication is performed between a UE and UL-only TRPs in an asymmetric mTRP environment.

[0063] This disclosure may be subject to various modifications and various embodiments. Specific embodiments are illustrated and described in detail in the drawings. However, this is not intended to limit the disclosure to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the disclosure.

[0064] While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present disclosure, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component." The term "and / or" includes a combination of multiple related items described herein or any of multiple related items described herein.

[0065] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0066] The terminology used in this disclosure is only used to describe specific embodiments and is not intended to limit the present disclosure. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this disclosure, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0067] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which this disclosure pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0068] A communication system to which embodiments according to the present disclosure are applied will be described. The communication system to which embodiments according to the present disclosure are applied is not limited to the scope described below, and embodiments according to the present disclosure can be applied to various communication systems. Here, the term "communication system" may be used interchangeably with "communication network."

[0069] Throughout the specification, the network may include, for example, wireless internet such as WiFi (wireless fidelity), mobile internet such as WiBro (wireless broadband internet) or WiMax (world interoperability for microwave access), 2G mobile communication networks such as GSM (global system for mobile communication) or CDMA (code division multiple access), 3G mobile communication networks such as WCDMA (wideband code division multiple access) or CDMA2000, 3.5G mobile communication networks such as HSDPA (high speed downlink packet access) or HSUPA (high speed uplink packet access), 4G mobile communication networks such as LTE (long term evolution) or LTE-Advanced, and 5G mobile communication networks.

[0070] Throughout the specification, a terminal may refer to a mobile station, a mobile terminal, a subscriber station, a portable subscriber station, a user equipment, an access terminal, etc., and may include all or part of the functions of a terminal, a mobile station, a mobile terminal, a subscriber station, a portable subscriber station, a user equipment, an access terminal, etc.

[0071] Here, a desktop computer, laptop computer, tablet PC, wireless phone, mobile phone, smart phone, smart watch, smart glass, e-book reader, portable multimedia player (PMP), portable game console, navigation device, digital camera, digital multimedia broadcasting (DMB) player, digital audio recorder, digital audio player, digital picture recorder, digital picture player, digital video recorder, digital video player, etc. capable of communicating with the terminal can be used.

[0072] Throughout the specification, a base station may also refer to an access point, a radio access station, a node B, an evolved node B, a base transceiver station, a mobile multihop relay (MMR)-BS, etc., and may include all or part of the functions of a base station, an access point, a radio access station, a node B, an eNodeB, a base transceiver station, an MMR-BS, etc.

[0073] Hereinafter, preferred embodiments of the present disclosure will be described in more detail with reference to the attached drawings. In order to facilitate an overall understanding in describing the present disclosure, identical reference numerals are used for identical components in the drawings, and redundant descriptions of identical components are omitted.

[0074] Figure 1 is a conceptual diagram illustrating one embodiment of a communication system.

[0075] Referring to FIG. 1, a 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). The plurality of communication nodes may support 4G communication (e.g., long term evolution (LTE), advanced LTE-A (LTE-A), 5G communication (e.g., new radio (NR)), etc.) specified in the 3rd generation partnership project (3GPP) standard. 4G communication may be performed in a frequency band of 6 GHz or less, and 5G communication may be performed in a frequency band of 6 GHz or more as well as a frequency band of 6 GHz or less.

[0076] For example, for 4G communication and 5G communication, multiple communication nodes can support a communication protocol based on CDMA (code division multiple access), a communication protocol based on WCDMA (wideband CDMA), a communication protocol based on TDMA (time division multiple access), a communication protocol based on FDMA (frequency division multiple access), a communication protocol based on OFDM (orthogonal frequency division multiplexing), a communication protocol based on Filtered OFDM, a communication protocol based on CP (cyclic prefix)-OFDM, a communication protocol based on DFT-s-OFDM (discrete Fourier transform-spread-OFDM), a communication protocol based on OFDMA (orthogonal frequency division multiple access), a communication protocol based on SC (single carrier)-FDMA, a communication protocol based on NOMA (Non-orthogonal Multiple Access), a communication protocol based on GFDM (generalized frequency division multiplexing), a communication protocol based on FBMC (filter bank multi-carrier), a communication protocol based on UFMC (universal filtered multi-carrier), a communication protocol based on SDMA (Space Division Multiple Access), etc.

[0077] In addition, the communication system (100) may further include a core network. If the communication system (100) supports 4G communication, the core network may include a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), a mobility management entity (MME), etc. If the communication system (100) supports 5G communication, the core network may include a user plane function (UPF), a session management function (SMF), an access and mobility management function (AMF), etc.

[0078] Meanwhile, each of the 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) constituting the communication system (100) may have the following structure.

[0079] Figure 2 is a block diagram illustrating one embodiment of a communication node constituting a communication system.

[0080] Referring to FIG. 2, a communication node (200) may include at least one processor (210), a memory (220), and a transmission / reception device (230) that is connected to a network and performs communication. In addition, the communication node (200) may further include an input interface device (240), an output interface device (250), a storage device (260), etc. Each component included in the communication node (200) may be connected by a bus (270) and communicate with each other.

[0081] However, each component included in the communication node (200) may be connected through an individual interface or individual bus centered around the processor (210), rather than a common bus (270). For example, the processor (210) may be connected to at least one of a memory (220), a transmission / reception device (230), an input interface device (240), an output interface device (250), and a storage device (260) through a dedicated interface.

[0082] The processor (210) can execute program commands stored in at least one of the memory (220) and the storage device (260). The processor (210) may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor in which the methods according to embodiments of the present disclosure are performed. Each of the memory (220) and the storage device (260) may be configured with at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory (220) may be configured with at least one of a read-only memory (ROM) and a random access memory (RAM).

[0083] 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). The communication system (100) including the base stations (110-1, 110-2, 110-3, 120-1, 120-2) and the terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as an “access network.” The first base station (110-1), the second base station (110-2), and the third base station (110-3) can each form a macro cell. The fourth base station (120-1) and the fifth base station (120-2) can each form a small cell. The fourth base station (120-1), the third terminal (130-3), and the fourth terminal (130-4) can be within the cell coverage of the first base station (110-1). The second terminal (130-2), the fourth terminal (130-4), and the fifth terminal (130-5) can be within the cell coverage of the second base station (110-2). The fifth base station (120-2), the fourth terminal (130-4), the fifth terminal (130-5), and the sixth terminal (130-6) 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).

[0084] 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, an evolved NodeB, a BTS (base transceiver station), a radio base station, a radio transceiver, an access point, an access node, an RSU (road side unit), a RRH (radio remote head), a TP (transmission point), a TRP (transmission and reception point), an eNB, a gNB, etc.

[0085] Each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) may be referred to as a UE (user equipment), a terminal, an access terminal, a mobile terminal, a station, a subscriber station, a mobile station, a portable subscriber station, a node, a device, an IoT (Internet of Things) device, an onboard device (mounted module / device / terminal or onboard device / terminal, etc.).

[0086] Meanwhile, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may operate in a different frequency band or may operate in the same frequency band. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to each other via an ideal backhaul link or a non-ideal backhaul link, and may exchange information with each other via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may be connected to the core network via the ideal backhaul link or the non-ideal backhaul link. Each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) can transmit a signal received from the core network to the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6), and can transmit a signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) to the core network.

[0087] Additionally, each of the plurality of base stations (110-1, 110-2, 110-3, 120-1, 120-2) may support MIMO transmission (e.g., single user (SU)-MIMO, multi user (MU)-MIMO, massive MIMO, etc.), coordinated multipoint (CoMP) transmission, carrier aggregation (CA) transmission, transmission in an unlicensed band, device to device communication (D2D) (or, proximity services (ProSe)), etc. Here, each of the plurality of terminals (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) can perform an operation corresponding to the base station (110-1, 110-2, 110-3, 120-1, 120-2) and an operation supported by the base station (110-1, 110-2, 110-3, 120-1, 120-2). For example, the second base station (110-2) can transmit a signal to the fourth terminal (130-4) based on the SU-MIMO scheme, and the fourth terminal (130-4) can receive a signal from the second base station (110-2) by the SU-MIMO scheme. Alternatively, the second base station (110-2) can transmit signals to the fourth terminal (130-4) and the fifth terminal (130-5) based on the MU-MIMO method, and each of the fourth terminal (130-4) and the fifth terminal (130-5) can receive signals from the second base station (110-2) based on the MU-MIMO method.

[0088] 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 D2D 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 D2D under the control of the second base station (110-2) and the third base station (110-3).

[0089] Next, methods for setting up and managing a wireless interface in a communication system will be described. Even if a method (e.g., signal transmission or reception) performed by a first communication node among communication nodes is described, a corresponding second communication node can perform a method (e.g., signal reception or transmission) corresponding to the method performed by the first communication node. That is, if the operation of a terminal is described, the corresponding base station can perform an operation corresponding to the operation of the terminal. Conversely, if the operation of a base station is described, the corresponding terminal can perform an operation corresponding to the operation of the base station.

[0090] Meanwhile, in a communication system, a base station can perform all functions of a communication protocol (e.g., remote radio transmission / reception function, baseband processing function). Alternatively, among all functions of a communication protocol, the remote radio transmission / reception function can be performed by a transmission reception point (TRP) (e.g., f(flexible)-TRP), and among all functions of a communication protocol, the baseband processing function can be performed by a baseband unit (BBU) block. A TRP can be a remote radio head (RRH), a radio unit (RU), a transmission point (TP), etc. A BBU block can include at least one BBU or at least one digital unit (DU). A BBU block can be referred to as a "BBU pool", a "centralized BBU", etc. A TRP can be connected to a BBU block via a wired fronthaul link or a wireless fronthaul link. A communication system consisting of a backhaul link and a fronthaul link can be as follows. When the function split method of the communication protocol is applied, the TRP can selectively perform some functions of the BBU or some functions of the MAC (medium access control) / RLC (radio link control).

[0091] In the present disclosure described below, a node communicating with a base station or a transmission / reception point (TRP) will be referred to as user equipment (UE). The TRP may also be controlled by a base station (BS). The UE, BS, and / or TRP may include at least some of the configurations of FIG. 2 described above, and may further have additional configurations. For example, the UE may further include various interfaces and / or sensors for user convenience. The BS may further include interfaces (e.g., backhaul interfaces and / or fronthaul interfaces) for communicating with the TRP, other BSs, and / or specific network functions (NFs) of the core network. The TRP may further include interfaces for communicating with the BS. However, it should be noted that this is for convenience of description and is not limited thereto. All possible configurations read by the concepts of the methods, procedures, and devices according to the present disclosure may be included within the scope of the present disclosure.

[0092] Figure 3a is a conceptual diagram for explaining signal transmission between intra-cell multiple TRPs and UE, and Figure 3b is a conceptual diagram for explaining signal transmission between inter-cell multiple TRPs and UE.

[0093] Before referring to FIGS. 3A and 3B, it should be noted that the UEs described below may be understood as either terminals and / or mobile stations (MSs), as described above. TRPs may belong to the same BS or to different BSs.

[0094] Referring to FIG. 3A, a case in which two different TRPs (311, 312) are included in a single cell (310) is exemplified. A single cell (310) may be an area governed by a single BS as described above. An area governed by a single BS may mean that the physical cell identifiers (PCIs) within the cell (310) are the same. In other words, the first TRP (311) and the second TRP (312) may broadcast the same PCI to the UE (301) within the cell (310). Although the example of FIG. 3A exemplifies only the case in which two TRPs (311, 312) exist within a single cell (310), the present disclosure is not limited thereto. In other words, the present disclosure may include both the case in which only one TRP exists within a single cell (310) and / or the case in which three or more TRPs exist. Therefore, FIG. 3A may be an example of a case where multiple TRPs (mTRPs) are included within a single cell. The mTRPs being included within a single cell may mean that the mTRPs broadcast the same PCI. Accordingly, the UE (301) may receive the same PCI from each of the two TRPs (311, 312). As described above, the case where two or more TRPs are included within a single cell (310) will be referred to as an "intra-cell mTRP environment" or an "intra-cell mTRP scenario" in the following description.

[0095] Referring to FIG. 3B, a case is illustrated where each of different cells (320, 330) includes one TRP (321, 331). As described above, each of the cells (320, 330) may be an area governed by a corresponding BS. In other words, the first cell (320) may be an area governed by the first BS (not shown in FIG. 3B), and the second cell (330) may be an area governed by the second BS (not shown in FIG. 3B). Accordingly, when the PCI of the first cell (320) is referred to as the first PCI, the first BS and the third TRP (321) may broadcast the first PCI, and when the PCI of the second cell (330) is referred to as the second PCI, the second BS and the fourth TRP (331) may broadcast the second PCI. If UE (301) communicates with first cell (320), second cell (330) may be an adjacent cell. In another example, if UE (301) communicates with second cell (330), first cell (320) may be an adjacent cell. In FIG. 3B, a case in which only one TRP exists in a cell is exemplified, but the present disclosure is not limited thereto. In other words, the same applies to a case in which two or more TRPs broadcasting the PCI of the corresponding cell exist in a cell. Accordingly, UE (301) may receive the PCI of the corresponding cell(s) from one cell and / or two or more cells. As described above, when there is one or more TRPs in each of the cells, and the UE (301) receives a first PCI from a TRP (e.g., a third TRP (321)) belonging to one serving cell (e.g., a first cell (320)) and receives a second PCI from a TRP (e.g., a fourth TRP (331)) of a non-serving cell (e.g., a second cell (330)) that is not the serving cell, this case is referred to as an “inter-cell environment” or “inter-cell scenario.”

[0096] Figure 4 is a conceptual diagram illustrating signal transmission between a TRP and a UE in an asymmetric mTRP scenario.

[0097] Referring to FIG. 4, a base station (441) can communicate with a UE (411) located within its cell using multiple TRPs (401, 402, 403). In the example of FIG. 4, only three TRPs (401, 402, 403) are illustrated for simplicity of the drawing. However, the number of TRPs that can be included in the base station (441) is not limited to three. In other words, the base station (441) may include only one TRP, or two TRPs, or four or more TRPs. However, since the present disclosure describes an mTRP environment, the case where the base station (441) includes only one TRP is not considered.

[0098] In the embodiment of FIG. 4, it is assumed that three different TRPs are included in one base station (441). The first TRP (401) may have a first cell area (410), the second TRP (402) may have a second cell area (420), and the third TRP (403) may have a third cell area (430). As illustrated in FIG. 4, the first cell area (410) formed by the first TRP (401) may be a cell having the widest area, and the first cell area (410) may overlap with the second cell area (420) and the third cell area (430). More specifically, the second cell region (420) formed by the second TRP (402) may be included within the first cell region (410), and the third cell region (430) formed by the third TRP (403) may be included within the first cell region (410).

[0099] In general, the transmission distance of a signal, or cell area, can be inversely proportional to the square of the distance. When the transmission power is the same, the signal cell areas can have the same size. Based on this, it can be seen from the configuration of the cell areas (410, 420, 430) illustrated in FIG. 4 that the second TRP (402) and the third TRP (403) are low-power TRPs compared to the first TRP (401). In the example of FIG. 4, a portion of the second cell area (420) overlaps a portion of the third cell area (430). However, the second cell area (420) and the third cell area (430) may not overlap each other.

[0100] Meanwhile, the first TRP (401) can perform downlink (DL) and uplink (UL) transmission with the UE (411), and the second TRP (402) and / or the third TRP (403) can also perform downlink and uplink transmission with the UE (411). In the example of FIG. 4, the UE (411) is located outside the second cell (420) set by the second TRP (402), but this is due to the constraints of the drawing, and in the description below, it is assumed that the UE (411) is located within the second cell (420). In addition, in the example of FIG. 4, the UE (411) is located outside the third cell (430) set by the third TRP (403), but this is due to the constraints of the drawing, and in the description below, it is assumed that the UE (511) is located within the third cell (430). In FIG. 4, the downlink transmission from the second TRP (402) to the UE (411) is illustrated as “minimum transmission,” and the downlink transmission from the third TRP (403) to the UE (411) is illustrated as “minimum transmission.” Here, “minimum transmission” may mean that a very small amount of data (or signal) including control information is transmitted.

[0101] In FIG. 4, the drawing illustrates that UE (411) is the "most transmit" for uplink transmission to the second TRP (402), and the drawing illustrates that UE (411) is the "most transmit" for uplink transmission to the third TRP (403). Here, "most transmit" may mean that a very large amount of data (or signal) including control information is transmitted. In other words, "most transmit" may mean that most of the data (or signal) is transmitted.

[0102] On the other hand, it should be noted that in the example of FIG. 4, the first TRP (401) did not indicate anything regarding the downlink transmission to the UE (411). The downlink transmission from the first TRP (401) to the UE (411) without any indication may mean transmission in accordance with the communication standard. In other words, the downlink transmission from the first TRP (401) to the UE (411) may mean that all control information as well as data may be transmitted via the downlink. Similarly, it should be noted that in the example of FIG. 4, the uplink transmission from the UE (411) to the first TRP (401) did not indicate anything. The uplink transmission from the UE (411) to the first TRP (401) without any indication may mean transmission in accordance with the communication standard. In other words, uplink transmission from UE (411) to the first TRP (401) may mean that all control information as well as data can be transmitted via the uplink.

[0103] Meanwhile, as illustrated in FIG. 4, when three different TRPs (401, 402, 403) are configured within a base station (441), transmission of downlink data to a UE (411) may be primarily performed by the first TRP (401). On the other hand, as illustrated in FIG. 4, when three different TRPs (401, 402, 403) are configured within a base station (441), uplink data transmitted by a UE (411) may be primarily transmitted to the second TRP (402) and / or the third TRP (403). This is because transmitting data via the closest one TRP or the closest two TRPs may reduce transmission power consumption of the UE (411). Therefore, when having the configuration of FIG. 4, the UE (411) can transmit data through the uplink to the second TRP (402) and / or the uplink to the third TRP (403).

[0104] This scenario, where uplink and downlink data are transmitted via different TRPs, will be referred to as the "asymmetric mTRP scenario" in the following description. On the other hand, the mTRP scenario illustrated in FIGS. 3A and 3B described above, where uplink and downlink transmissions occur via a single TRP, can be referred to as the "symmetric mTRP scenario."

[0105] In the asymmetric mTRP scenario illustrated in FIG. 4, the current standard does not specify how the UE (411) performs the initial system connection. In addition, in the asymmetric mTRP scenario illustrated in FIG. 4, the current standard does not specify the uplink synchronization method between the UE (411) and each of the low-power TRPs (402, 403). Furthermore, in the asymmetric mTRP scenario, the current standard does not specify the procedure for determining the uplink transmission power of the UE (411) and the uplink data transmission. Therefore, a method for performing the initial connection, the uplink synchronization method, the uplink power determination method, and the uplink data transmission is required in the asymmetric mTRP scenario.

[0106] In the present disclosure described below, a wireless communication device will be referred to as a UE, a device that receives a signal from the UE will be referred to as a TRP, and a device that manages the TRP will be referred to as a base station (BS). The upper layer that manages the BS will be referred to as a network (NW) or core NW, and the area managed by the BS will be referred to as a cell.

[0107] Figure 5 is a conceptual diagram illustrating the first scenario in an asymmetric mTRP environment.

[0108] Referring to FIG. 5, a base station (541) can be connected to a first TRP (501), a second TRP (502), and a third TRP (503), and can communicate with a UE (511) through the TRPs (501, 502, 503). The base station (541) can directly control the first TRP (501), the second TRP (502), and the third TRP (503) or indirectly through other TRPs. The first TRP (501) can perform downlink and / or uplink transmissions with UE(s) within a first cell (510) established by the first TRP (501). The second TRP (502) can perform downlink and / or uplink transmission with UE(s) within the second cell (520) established by the second TRP (502), and the third TRP (503) can also perform downlink and / or uplink transmission with UE(s) within the third cell (530) established by the third TRP (503). In the example of FIG. 5, the UE (511) is illustrated as being located outside the second cell (520) established by the second TRP (502), but this is due to limitations of the drawing, and in the following description, it is assumed that the UE (511) is located within the second cell (520). In addition, in the example of FIG. 5, the UE (511) is exemplified as being located outside the third cell (530) set by the third TRP (503), but this is due to limitations of the drawing, and in the following description, it is assumed that the UE (511) is located within the third cell (530).

[0109] The example of FIG. 5 may be a diagram assuming an asymmetric mTRP environment. The first TRP (501) may be a TRP capable of downlink (DL) and uplink (UL) transmission as previously described in FIG. 4. The first TRP (501) may also be referred to as a "head TRP" or a "macro TRP." The second TRP (502) and / or the third TRP (503) may be referred to as "low power TRPs (LPTs)" and may only transmit control information limited to the downlink. In the example of FIG. 5, each of the second TRP (502) and / or the third TRP (503) exemplifies a case in which only SSB(s) are transmitted (or broadcast) within its own cell area (520, 530).

[0110] According to one of the methods presented in the work item description (WID) of the current 3GPP Rel-19, a method to reduce the downlink transmission of micro nodes, i.e. LPTs, has been proposed as an option to further reduce energy consumption. Therefore, in a first scenario of an asymmetric mTRP environment, it is assumed that the second TRP (502) and / or the third TRP (503) can only transmit synchronization signal block (SSB)(s) ​​and / or channel state information reference signal (CSI-RS)(s) as a method to reduce the downlink transmission.

[0111] Meanwhile, since the second TRP (502) and the third TRP (503) are both located within the first cell area (510) of the first TRP (501), it can be understood that the first TRP (501) controls them. In the first scenario of the asymmetric mTRP environment, the first TRP (501), the second TRP (502), and the third TRP (503) can each have different physical cell identities (PCIs). According to the example of FIG. 5, the first TRP (501) has PCT p, the second TRP (502) has PCT q, and the third TRP (503) has PCT b.

[0112] In the first scenario of an asymmetric mTRP environment, each of the second TRP (502) and the third TRP (503) can save energy by transmitting only SSB(s) and / or CSI-RS(s) to the UE (511). In this case, if each of the second TRP (502) and the third TRP (503) transmits only SSB(s) and / or CSI-RS(s) to the UE (511), inefficient decoding and regulation issues for a new master information block (MIB) may occur.

[0113] Referring to FIG. 5, the UE (511) may be closer to the third TRP (503) than to the first TRP (501) and the second TRP (502). When the UE (511) attempts initial connection, the UE (511) may receive SSBs from each of the first TRP (501), the second TRP (502), and the third TRP (503). The UE (511) may select the SSB received from the third TRP (503), which is closest to the UE (511), as the optimal SSB among the SSBs received from each of the first TRP (501), the second TRP (502), and the third TRP (503). At this time, since the second TRP (502) and the third TRP (503) are both LPTs, the second TRP (502) and the third TRP (503) can transmit an SSB that does not include an MIB to the UE (511) to further reduce power consumption. If the second TRP (502) and the third TRP (503), which are LPTs, transmit an SSB that does not include an MIB to the UE (511), the following problems may occur.

[0114] To obtain initial synchronization, the UE (511) must select the optimal SSB among the SSBs received from each of the TRPs and decode the selected optimal SSB. At this time, if the UE (511) selects the SSB received from the third TRP (503) as the optimal SSB, the UE (511) can decode the SSB received from the third TRP (503). However, since the third TRP (503) transmits an SSB that does not include a MIB, the UE (501) cannot obtain the MIB even if it decodes the SSB received from the third TRP (503). In this way, the UE (501) must decode the SSB to determine whether the SSB includes a MIB. Consequently, the UE (511) may consume unnecessary power to decode the SSB received from the third TRP (503). In addition, to find the SSB on which the MIB is transmitted, other optimal SSBs may need to be selected and the selected SSBs may need to be decoded again. Therefore, the UE (511) may need to consume unnecessary power to find the appropriate SSB.

[0115] As another example, the second TRP (502) and the third TRP (503), which are LPTs, may transmit an SSB containing a MIB to the UE (511). When the second TRP (502) and the third TRP (503), which are LPTs, transmit an SSB containing a MIB to the UE (511), the following problems may occur.

[0116] When the second TRP (502) and the third TRP (503), which are LPTs, each transmit a MIB included in the SSB, the UE (511) can receive the SSB and obtain the MIB included in the SSB. In this case, the UE (511) can select the SSB received from the third TRP (503) closest to the UE (511) as the optimal SSB. In addition, the UE (501) can decode the SSB received from the third TRP (503) to obtain the MIB included in the SSB. In general, the MIB may include information for receiving system information block 1 (SIB1). However, since the second TRP (502) and the third TRP (503) are LPTs, control information must also be transmitted to a minimum, and thus transmission of SIB1, etc. may not occur. Therefore, it is necessary to inform the UE (511) that the MIB included in the SSB has a different configuration from the MIB transmitted by the general TRP. This is because the second TRP (502) and the third TRP (503), which are LPTs, do not transmit SIB1. In other words, it is necessary to inform the UE (511) that the MIB included in the SSB transmitted by the second TRP (502) and the third TRP (503) does not contain information about SIB1. In this way, additional time / frequency resources may be required for the MIB to inform that the MIB included in the SSB transmitted by the second TRP (502) and the third TRP (503), which are LPTs, is different from the general MIB. In other words, there is a problem that a configuration method for a new MIB must be proposed.

[0117] Therefore, the first scenario of an asymmetric mTRP environment, such as that shown in Figure 5, may not be suitable for improving uplink capacity. However, the problems described above may be resolved by utilizing the methods presented in the scenario(s) described below. This will be further detailed in the other scenario(s).

[0118] On the other hand, when using the first scenario in an asymmetric mTRP environment, it is also possible to use fields specified in the current 5G new radio (NR) standard to indicate that the MIB included in the SSB transmitted by the second TRP (502) and the third TRP (503) is different from the general MIB.

[0119] A MIB according to the 5G NR standard may be composed of multiple fields, and among the multiple fields constituting the MIB, there is a "cellBarred" field consisting of 1 bit. If the cellBarred field of the MIB has a value of 1, it may mean that a cell is not defined, and if the cellBarred field of the MIB has a value of 0 (zero), it may mean that a cell is defined. In one embodiment of the present disclosure, the cellBarred field of the MIB may be used to indicate whether SIB1 is transmitted thereafter using the MIB in the SSB transmitted by the TRP.

[0120] For example, if the cellBarred field of the MIB has a value of 1, the UE (511) can determine that SIB1 is not transmitted, and if the cellBarred field of the MIB has a value of 0, the UE (511) can determine that SIB1 is transmitted. In other words, the second TRP (502) and / or the third TRP (503) can transmit the MIB including the SSB, and can instruct the UE (511) that SIB1 will not be transmitted thereafter by transmitting it with the cellBarred field of the MIB set to a value of 1. In addition, the first TRP (501) can transmit the MIB including the SSB, and can instruct the UE (511) that SIB1 will be transmitted thereafter by transmitting it with the cellBarred field of the MIB set to a value of 0. Therefore, in the first scenario of an asymmetric mTRP environment, each TRP can use the cellBarred field of the MIB to inform the UE (511) whether or not to transmit SIB1, and the UE (511) can determine the TRP that can acquire SIB1 by decoding and confirming the cellBarred field of the MIB. Accordingly, the UE (511) can confirm the TRP that transmits SIB1 and can attempt an initial connection with the TRP that transmits SIB1.

[0121] However, even if the cellBarred field of the MIB is used, there may be a problem that the UE (511) may repeatedly decode the SSB received from the mTRPs several times and that each TRP must consume more power for transmission of the SSB.

[0122] The example described above is examined with reference to FIG. 5 as follows. Each of the first TRP (501), the second TRP (502), and the third TRP (503) can transmit an SSB including a MIB to the UE (511). At this time, the first TRP (501) can transmit the MIB by setting the cellBarred field value to 0, and the second TRP (502) and the third TRP (503) can transmit the MIB by setting the cellBarred field value to 1. Accordingly, the UE (511) can receive an SSB including a MIB from each of the first TRP (501), the second TRP (502), and the third TRP (503), and can check the cellBarred field value by decoding the MIB. The UE (511) that must perform an initial connection to the base station (441) can determine the TRP on which to perform the initial connection based on the checked cellBarred field value. In the case of FIG. 5, the UE (511) can select the first TRP (501).

[0123] In the following description, an SSB transmitted with the cellBarred field value set to 0 is referred to as a "cell defining (CD) SSB," and an SSB transmitted with the cellBarred field value set to 1 is referred to as a "non-cell defining (NCD) SSB."

[0124] In a simple explanation of the initial system access procedure of UE (511) according to the first scenario in an asymmetric mTRP environment, it can operate as follows.

[0125] When the UE (511) is powered on, the UE (511) can move (raster) through the frequency synchronization channel defined in the 5G NR standard for initial system access to find the best CD SSB that has the highest signal strength above a specific (or preset) threshold. Finding the best CD SSB can be understood as finding a TRP for performing synchronization. The UE (511) can perform downlink timing synchronization and frequency synchronization using the best CD SSB, and can obtain PCI and MIB from the best CD SSB. According to the example of FIG. 5, the TRP transmitting the best CD SSB may be the first TRP (501). Therefore, the UE (511) can obtain the PCI p of the first TRP (501).

[0126] In addition, the UE (511) can obtain SIB1 from the first TRP (501), which is a TRP that performs synchronization based on information included in the MIB. The UE (511) can perform a random access procedure with the first TRP (501), which is a TRP that has received the MIB and SIB1, based on the information obtained from the MIB and SIB1. The UE (511) can receive a radio resource control (RRC) message (or an RRC configuration message) from the first TRP (501) through the random access procedure, and can enter an RRC connected state capable of communicating with the first TRP (501) by transmitting an RRC reconfiguration complete message to the first TRP (501).

[0127] Meanwhile, in the current 5G NR standard, SSB can be transmitted every 20ms. When performing a synchronization raster, the UE (511) can receive CD SSB(s) from the first TRP (501) through a frequency resource group, for example, a bandwidth part (BWP). In addition, as described above, when performing a synchronization raster, the UE (511) can also receive NCD SSB(s) from the second TRP (502) and / or the third TRP (503). According to the first scenario of the asymmetric mTRP environment, there is a problem that unnecessary power consumption may occur because the UE (511) can receive NCD SSB(s) from the second TRP (502) and / or the third TRP (503).

[0128] In the first scenario in an asymmetric mTRP environment, in order to prevent the UE (511) from receiving NCD SSB(s) from the second TRP (502) and / or the third TRP (503), the second TRP (502) and / or the third TRP (503) may transmit the NCD SSB(s) through a different frequency resource group (e.g., BWP) than the BWP used by the UE (511) when performing the synchronization raster.

[0129] Meanwhile, an uplink-only TRP (UL-only TRP) does not transmit (or broadcast) a signal to the UE (511) to indicate the existence of the TRP in the downlink. Therefore, an "uplink-only TRP" may also be referred to as an "unknown uplink-only TRP." Since an uplink-only TRP does not transmit any signal to the UE (511), an "uplink out-of-synchronization" problem may occur. In addition, if the BWP transmitting the NCD SSB(s) transmitted by the second TRP (502) and / or the third TRP (503) is different from the BWP transmitted by the first TRP (510), as in the example described above, the second TRP (502) and the third TRP (503) may also become unknown uplink-only TRPs. In the present disclosure, the following method may be used to solve the uplink out-of-synchronization problem between an uplink-only TRP and a UE.

[0130] The UE (511) may complete link connection setup with the first TRP (511) transmitting CD SSB(s) as described above. Once link connection setup with the UE (511) is completed, the first TRP (511) may transmit information related to LPT(s) controlled (or managed) by the first TRP (511) to the UE (511) using RRC signaling and / or a medium access control-control element (MAC-CE). For example, the first TRP (511) may transmit time slots of SSB(s) transmitted by the LPT(s) controlled by the first TRP (511), frequency resource group information, transmission power information of the UE (511), etc. to the UE (511) via RRC signaling and / or MAC-CE. Here, the transmission power information of the UE (511) may be, for example, transmission power information required when the UE (511) transmits a preamble. More specifically, the transmission power information for the UE (511) to transmit the preamble may be transmission power information of the NCD SSB(s) transmitted by the second TRP (502) and / or the third TPR (503), which are LPTs, and / or the CD SSB(s) transmitted by the first TRP (501).

[0131] The UE (511) can receive the SSB(s) transmitted by the second TRP (502) and / or the third TRP (503) from information included in RRC signaling and / or MAC-CE, for example, time slot and frequency resource group information. Accordingly, the UE (511) can obtain the PCI(s) of the TRP that transmitted the optimal SSB among the SSBs above a (pre-set) threshold value by measuring the SSB(s) transmitted by the second TRP (502) and / or the third TRP (503). The UE (511) can report information on the optimal SSB(s) and the PCI pair corresponding to the optimal SSB(s) to the first TRP (501) using uplink MAC-CE, RRC signaling or uplink control indicator(or information) (UCI).

[0132] The first TRP (501) can determine candidate LPT(s) on which the UE (511) will perform uplink transmission based on information of SSB(s) and PCI(s) pairs received from the UE (511). In addition, the first TRP (501) can determine a path loss (PL) offset of the candidate LPT(s). In addition, the first TRP (501) can transmit a physical downlink control information (PDCCH)-order downlink control indicator(or information) (DCI) to the UE (511) to estimate uplink timing advance (TA)(s) between the UE (511) and the LTP(s). The PDCCH-order DCI can include information on one or more of resources, for example, a time slot and a frequency resource group, for transmitting a preamble to a specific TRP. Accordingly, the UE (511) can receive the PDCCH-order DCI and determine resources for transmitting a preamble using the information included in the PDCCH-order DCI. Thereafter, the UE (511) can transmit the preamble to the LPT using the resources indicated by the PDCCH-order DCI.

[0133] The second TRP (502) and / or the third TRP (503), which are LPTs, can receive a preamble from the UE (511), and thereby calculate the TA between the UE (511) and the second TRP (502) or the TA between the UE (511) and the third TRP (503). The TA information thus calculated can be transmitted to the UE (511) via the first TRP (501). Therefore, the uplink asynchronization problem between the uplink-only TRP and the UE can be resolved.

[0134] Thereafter, the base station (541) can update the PL offset between the uplink-only TRP and the UE. In addition, the base station (541) can update the joint / UL transmission configuration indication (TCI) state, PL offset, or uplink transmission power information corresponding to the direction in which the uplink-only TRP transmitted the SSB. If there are multiple candidate LPTs, the UE (511) can prevent monitoring a random access response (RAR) from the LPTs. Instead of monitoring the RAR from the candidate LPTs, the UE (511) can receive the RAR from the first TRP (501). In other words, information updated by the base station (541) or by the first TRP (501) can be transmitted to the UE (511) via the first TRP (501). The base station (541) or the first TRP (501) can transmit RAR to the UE (511) when necessary.

[0135] As illustrated in FIG. 5, since the PCIs of all TRPs located within the base station (541) are set differently, the above described operation for solving the uplink asynchronization problem may be suitable for frequency range 2 (FR2) using a directional beam pattern. However, the method for solving the uplink asynchronization problem described above may also be applied to FR1 using an omni-directional beam pattern.

[0136] Figure 6 is a conceptual diagram illustrating a second scenario in an asymmetric mTRP environment.

[0137] Referring to FIG. 6, a base station (641) can be connected to a first TRP (601), a second TRP (602), and a third TRP (603), and can communicate with a UE (611) through the TRPs (601, 602, 603). The base station (641) can directly control the first TRP (601), the second TRP (602), and the third TRP (603) or indirectly through other TRPs. The first TRP (601) can perform downlink and / or uplink transmissions with UE(s) within a first cell (610) established by the first TRP (601). The second TRP (602) can perform downlink and / or uplink transmission with UE(s) within the second cell (620) established by the second TRP (602), and the third TRP (603) can also perform downlink and / or uplink transmission with UE(s) within the third cell (630) established by the third TRP (603). In the example of FIG. 6, the UE (611) is illustrated as being located outside the second cell (620) established by the second TRP (602), but this is due to limitations of the drawing, and in the following description, it is assumed that the UE (611) is located within the second cell (620). In addition, in the example of FIG. 6, the UE (611) is exemplified as being located outside the third cell (630) set by the third TRP (603), but this is due to limitations of the drawing, and in the following description, it is assumed that the UE (611) is located within the third cell (630).

[0138] The example of FIG. 6 may be a diagram assuming an asymmetric mTRP environment. The first TRP (601) may be a TRP capable of downlink (DL) and uplink (UL) transmission as described above in FIGS. 4 and 5. As described in FIG. 5, the first TRP (601) may also be referred to as a head TRP or a macro TRP. Each of the second TRP (602) and the third TRP (603) may be referred to as an LPT and may transmit only control information limited to the downlink. In the example of FIG. 6, each of the second TRP (602) and / or the third TRP (603) exemplifies a case in which only SSB(s) are transmitted (or broadcast) within its own cell area (620, 630).

[0139] The second scenario of the asymmetric mTRP environment illustrated in FIG. 6 may be similar to the first scenario of the asymmetric mTRP environment described in FIG. 5 above. More specifically, the second TRP (602) and / or the third TRP (603), which are LPTs, may transmit only SSB(s) and / or CSI-RS(s) to reduce DL transmission. However, in the first scenario of the asymmetric mTRP environment illustrated in FIG. 5 above, the first TRP (501), the second TRP (502), and the third TRP (503) may all use different PCIs. On the other hand, in the second scenario of the asymmetric mTRP environment illustrated in FIG. 6, the second TRP (602) and / or the third TRP (603), which are LPTs, may use the same PCI as the first TRP (601), which is a header TRP. In other words, in the second scenario of the asymmetric mTRP environment illustrated in FIG. 6, the first TRP (601), the second TRP (602), and the third TRP (603) may share the same PCI. More specifically, the first TRP (601), the second TRP (602), and the third TRP (603) may all have PCT p.

[0140] The second scenario of the asymmetric mTRP environment illustrated in Figure 6 may also encounter issues, such as requiring the UE to perform unnecessary decoding and defining a new MIB, as described in the first scenario of the asymmetric mTRP environment. Therefore, the second scenario of the asymmetric mTRP environment may also not be suitable for improving uplink capacity.

[0141] Referring to FIG. 6, each of the first TRP (601), the second TRP (602), and the third TRP (603) can broadcast an SSB. At this time, since both the second TRP (602) and the third TRP (603) are LPTs, they can transmit an SSB without an MIB to the UE (611) to further reduce power consumption. As another example, each of the second TRP (602) and the third TRP (603) can include an MIB in the SSB(s) and use a cellBarred field among the multiple fields included in the MIB to indicate that they are uplink-only TRPs. As another example, the second TRP (602) and the third TRP (603) can use a different BWP from the first TRP (601).

[0142] Therefore, when the UE (611) is powered on, the UE (611) can move (raster) through the frequency synchronization channels defined in the 6G NR standard for initial system access and find the best CD SSB that has the highest signal strength above a specific (or preset) threshold. Thereafter, the UE (611) can be RRC-connected with the first TRP (601) through a four-step random access (RA) procedure. In other words, the UE (611) can establish a link connection of the initial access procedure and enter a connected state in which communication is possible.

[0143] As previously explained, in the 6G NR standard, SSBs can be transmitted every 20 ms. When the UE (611) performs a synchronization raster, it can receive CD SSB(s) from the first TRP (601) through a frequency resource group, for example, a BWP. If the second TRP (602) and the third TRP (603) do not transmit SSBs through a BWP different from the first TRP (601), the UE (611) may consume unnecessary power to receive and decode the SSBs transmitted by the second TRP (602) and the third TRP (603), as explained in FIG. 6.

[0144] If the second TRP (602) and the third TRP (603) transmit SSB through a different BWP than the first TRP (601), the UE (611) can receive resource information, for example, time slot or frequency resource group information, through RRC signaling and / or MAC-CE, through which the NCD SSB transmitted by each of the second TRP (602) and the third TRP (603) is transmitted.

[0145] The UE (611) can receive the SSB(s) transmitted by the second TRP (602) and / or the third TRP (603) from information included in RRC signaling and / or MAC-CE, for example, time slot and frequency resource group information. Accordingly, the UE (611) can obtain the PCI(s) of the TRP that transmitted the optimal SSB among the SSBs above a (pre-set) threshold value by measuring the SSB(s) transmitted by the second TRP (602) and / or the third TRP (603). The UE (611) can report information on the optimal SSB(s) and the PCI pair corresponding to the optimal SSB(s) to the first TRP (601) using uplink MAC-CE, RRC signaling or uplink control indicator(or information) (UCI).

[0146] The first TRP (601) can determine candidate LPT (s) on which the UE (611) will perform uplink transmission based on information of SSB (s) and PCI (s) pairs received from the UE (611). In addition, the first TRP (601) can determine the PL offset of the candidate LPT (s). In addition, the first TRP (601) can transmit PDCCH-order DCI to the UE (611) to estimate uplink TA (s) between the UE (611) and the LTP (s). The PDCCH-order DCI can include information on one or more of resources, for example, time slots and frequency resource groups, for transmitting a preamble to a specific TRP. Accordingly, the UE (611) can receive the PDCCH-order DCI and determine resources for transmitting a preamble using the information included in the PDCCH-order DCI. Afterwards, the UE (611) can transmit a preamble to LPT using the resources indicated by the PDCCH-order DCI.

[0147] The second TRP (602) and / or the third TRP (603), which are LPTs, can receive a preamble from the UE (611), and thereby calculate the TA between the UE (611) and the second TRP (602) or the TA between the UE (611) and the third TRP (603). The TA information thus calculated can be transmitted to the UE (611) via the first TRP (601).

[0148] The base station (641) can update the PL offset between the uplink-only TRP and the UE. In addition, the base station (641) can update the joint / UL TCI state, PL offset, or uplink transmission power information corresponding to the direction in which the uplink-only TRP transmitted the SSB. If there are multiple candidate LPTs, the UE (611) can not monitor RAR from the LPTs. Instead of monitoring RAR from the candidate LPTs, the UE (611) can receive RAR from the first TRP (601). In other words, information updated by the base station (641) or by the first TRP (601) can be transmitted to the UE (611) via the first TRP (601). The base station (641) or the first TRP (601) can transmit RAR to the UE (611) when necessary.

[0149] As illustrated in FIG. 6, since the PCIs of all TRPs located within the base station (641) are set identically, the above described operation for solving the uplink asynchronization problem may be suitable for FR1 using an omni-directional beam pattern. However, the method for solving the uplink asynchronization problem described above may also be applied to FR2 using a directional beam pattern.

[0150] Figure 7a is a conceptual diagram illustrating a third scenario in an asymmetric mTRP environment.

[0151] Referring to FIG. 7A, a base station (741) can be connected to a first TRP (701), a second TRP (702), and a third TRP (703), and can communicate with a UE (711) through the TRPs (701, 702, 703). The base station (741) can control the first TRP (701), the second TRP (702), and the third TRP (703) directly or indirectly through other TRPs. The first TRP (701) can perform downlink and / or uplink transmissions with UE(s) within a first cell (710) established by the first TRP (701). The second TRP (702), which is an uplink-only TRP, may have a second cell (720) set by the second TRP (702), and the third TRP (703), which is an uplink-only TRP, may also have a third cell (730) set by the third TRP (703). In the example of FIG. 7A, the UE (711) is exemplified as being located outside the second cell (720) set by the second TRP (702), but this is due to the constraints of the drawing, and in the following description, it is assumed that the UE (711) is located within the second cell (720). In addition, in the example of FIG. 7, the UE (711) is exemplified as being located outside the third cell (730) set by the third TRP (703), but this is due to the constraints of the drawing, and in the following description, it is assumed that the UE (711) is located within the third cell (730). Accordingly, the UE (711) can perform uplink transmission to the second TRP (702) and / or the third TRP (703).

[0152] According to one of the methods proposed in the WID of the current 3GPP Rel-19, as an option to further reduce energy consumption, micronodes (e.g., LPTs) may, for example, stop DL transmissions. In other words, LPT(s), which are UL-only TRPs, may not transmit any signals in the downlink. The third scenario in an asymmetric mTRP environment illustrated in FIG. 7A may be a case where an LPT, which is a UL-only TRP, does not transmit any signals in the downlink. The third scenario in an asymmetric mTRP environment has the advantage of not requiring unnecessary SSB decoding operations and / or defining a new MIB, as described in the first and second scenarios in an asymmetric mTRP environment. The present disclosure illustrated in FIG. 7A describes a method for improving uplink capacity in the third scenario in an asymmetric mTRP environment.

[0153] For the third scenario in an asymmetric mTRP environment, the following issues must be addressed. First, the UE cannot determine the appropriate uplink transmit power. In other words, excessive uplink power may be allocated to the data (or signal) transmitted by the UE via the uplink. This excessive uplink power may be a problem of excessive uplink received power from the perspective of the second TRP (702) and third TRP (703), which are LPTs.

[0154] Second, since the second TRP (702) and the third TRP (703), which are LPTs, are uplink-only TRPs that do not transmit any signals, there is a problem in that the UE cannot know the existence of the second TRP (702) and the third TRP (703) and cannot know the locations of the second TRP (702) and the third TRP (703).

[0155] Third, as in the first scenario in the mTRP environment and the second scenario in the mTRP environment, the uplink asynchrony problem still exists.

[0156] In the problem of excessive uplink reception power and unknown UL-only TRP locations, the UE (711) cannot know the locations of the second TRP (702) and the third TRP (703), since the UL-only TRPs, the second TRP (702) and the third TRP (703), do not transmit any physical signals and / or physical channels in the downlink. In particular, when using a beamforming method, the UE (711) cannot determine in which direction to transmit a signal (or data), nor can it determine the transmission power.

[0157] For example, in the case of FIG. 7a, when a UE (711) transmits a signal to a second TRP (702) using the transmission power transmitted to a first TRP (701), the distance between the UE (711) and the second TRP (702) is shorter than the distance between the UE (711) and the first TRP (701), so there is a problem that the second TRP (702) receives a physical signal and / or a physical channel with excessive transmission power from the UE (711). When a UE (711) transmits a signal to the second TRP (702) using the transmission power transmitted to the first TRP (701), there is also a problem that strong interference is caused to a third TRP (703), which is an adjacent uplink-only TRP. This strong interference causes strong interference to adjacent cells around the second TRP (702), and as a result, the goal of improving uplink capacity may not be achieved.

[0158] Additionally, due to the uplink desynchronization problem, the UE (711) cannot determine the transmission timing of the physical signal (or physical channel) to be transmitted to the UL-only TRP because the UL-only TRP does not transmit any physical signal (or physical channel) in the downlink.

[0159] If the UE (711) transmits a signal to the second TRP (702), which is an UL-only TRP, at the same transmission time as the time at which the UE (711) transmits a signal to the first TRP (701), the second TRP (702) may not be able to receive the signal transmitted by the UE (711) due to an uplink desynchronization problem. More specifically, according to the standard of the 3GPP communication system, a signal transmitted between a transmitting node and a receiving node may copy the last part of the data to be transmitted and add a cyclic prefix (CP) to the peak of the data to be transmitted. If the UE (711) transmits a signal to the second TRP (702), which is an UL-only TRP, at the same transmission time as the time at which the UE (711) transmits a signal to the first TRP (701), the second TRP (702) may be within the range that the second TRP (702) can receive, which is ±0.5T. CP A signal transmitted by UE (711) can be received at a location outside of T. Here, CP may mean the transmission time duration of CP for one symbol of a physical signal (or physical channel) transmitted by UE (711).

[0160] The range that the second TRP (702) can receive from the second TRP (702) is ±0.5T. CP When receiving a signal transmitted by UE (711) at a location outside of the orthogonality of the received signal, the orthogonality of the received signal is not guaranteed. Therefore, even if the second TRP (702) receives the signal transmitted by UE (711), there is a problem in that it cannot demodulate it. This problem may result in the failure to achieve the goal of improving the uplink capacity of the mobile communication system.

[0161] The signal received from the UE (711) to the second TRP (702), which is a UL-only TRP, has a very high signal-to-noise ratio (SNR), so if the uplink asynchrony problem can be resolved, the uplink capacity can be improved. In other words, resolving the uplink asynchrony problem can be a very important issue.

[0162] FIG. 7b is a timing diagram for explaining the transmission and reception times of signals between a UE and a TRP in a third scenario in an asymmetric mTRP environment.

[0163] Referring to FIG. 7B, T00 may denote an assumed Tx time point from the UE. Additionally, T04 may denote an Rx time point from the first TRP (701) to the UE (711). Therefore, the time duration from T00 to T04 may be a round-trip delay between the first TRP (701) and the UE (711). In other words, it may be a time delay from when the first TRP (701) transmits a signal to the UE (711), to when the UE (711) receives the signal, and then transmits the signal to the first TRP (701) and receives the signal at the first TRP (701).

[0164] T01 may be an example assuming an RX time point out of synchronization from UE to third TRP (703) in an asynchronous state, and T02 may be an example assuming an RX time point within synchronization from UE to second TRP (702) in a synchronized state. Finally, T03 may be an example assuming Tx / Rx time points from / to all of TRPs (first TRP, second TRP and third TRP).

[0165] The third scenario in the asymmetric mTRP environment of FIGS. 7A and 7B described above may be a worst-case scenario in which the location of the UE (711) attempting to access the initial system is out of synchronization. If the location of the UE (711) attempting to access the initial system is not out of synchronization, the UE (711) can initially smoothly access (or connect) the uplink-only TRP(s). Problems that may arise when the location of the UE (711) attempting to access the initial system is not out of synchronization and when the UE is moving are described below.

[0166] Figure 8a is a conceptual diagram illustrating scenario 3-1 in an asymmetric mTRP environment.

[0167] Referring to FIG. 8A, UE (811) may be the initial UE location, and UE (812) may mean a case where UE (811) has moved as indicated by reference numeral 850. Base station (841) may be connected to first TRP (801), second TRP (802), and third TRP (803), and may communicate with UE (811) through TRPs (801, 802, 803). Base station (841) may directly control first TRP (801), second TRP (802), and third TRP (803) or indirectly through other TRPs. First TRP (801) may perform downlink and / or uplink transmission with UE(s) within first cell (810) established by first TRP (801). The second TRP (802), which is an uplink-only TRP, may have a second cell (820) set by the second TRP (802), and the third TRP (803), which is an uplink-only TRP, may also have a third cell (830) set by the third TRP (803). The first TRP (801) may be a macro TRP.

[0168] According to the example of Fig. 8a, the initial UE (811) can establish a connection with the first TRP (801), which is a macro TRP, and is then connected to the second TRP (802), which is an uplink-only TRP, and the third TRP (803), which is another uplink-only TRP. At this time, if the UE (811) moves from the initial location as indicated by reference numeral 850 and enters the area of ​​the third TRP (803), which is a new location, an asynchronous problem as described in Fig. 7a may occur. The asynchronous problem is explained with reference to the attached Figs. 8b and 8c.

[0169] FIG. 8b is a timing diagram for explaining the transmission and reception times of signals between a UE and a TRP at an initial location where synchronization is acquired in scenario 3-1 in an asymmetric mTRP environment.

[0170] Referring to FIG. 8b, in an asymmetric mTRP environment, the UE (811) at the initial location may have acquired synchronization with all TRPs according to Scenario 3-1. As illustrated in FIG. 8b, T10 may be the assumed Tx time point at the UE.

[0171] In addition, T14 may mean the Rx time point from the first TRP (801) to the UE (811). Therefore, the time duration (861) from T00 to T04 may be a round-trip delay between the first TRP (801) and the UE (811). In other words, it may be a time delay from when the first TRP (801) transmits a signal to the UE (811) until the UE (811) receives the signal, and then the UE (811) transmits the signal to the first TRP (801) and receives it at the first TRP (801).

[0172] In FIG. 8B, T11 may refer to a reception time point within synchronization from UE (811) to third TRP (803), T12 may refer to a reception time point within synchronization from UE (811) to second TRP (802), and T13 may refer to an Rx reference time. Accordingly, a time section (862) from T10 to T13 may refer to a propagation delay between first TRP (801) and UE (811). T14 may refer to a reception time point from first TRP (801) to UE (811).

[0173] FIG. 8c is a timing diagram for explaining the transmission and reception times of signals between a UE and a TRP when the UE moves from an initial location where synchronization was acquired in scenario 3-1 in an asymmetric mTRP environment.

[0174] Referring to FIG. 8c, in an asymmetric mTRP environment, a UE (811) at an initial location may move as indicated by reference numeral 850 according to scenario 3-1. Accordingly, the UE (812) may have entered the third cell (830) of the third TRP (803). In this way, when the UE (812) moves into the third cell (830) of the third TRP (803), which is a new uplink-only TRP, synchronization between the third TRP (803) and the UE (811) may become out of sync.

[0175] In FIG. 8c, T20 may be an assumed Tx time point at UE from the moved UE (812). T21 may be an asynchronous reception time point (Rx time point out of synchronization from UE to third TRP) from the moved UE (812). Compared to FIG. 8b, the moved UE (812) may change from a synchronous state to an asynchronous state with the third TRP (803). In addition, T22 may be an Rx time point within synchronization from UE to second TRP from the moved UE (812) in a synchronous state to the second TRP (802), and T23 may be an Rx reference time. Therefore, the time section (872) from T20 to T23 may mean a propagation delay between the first TRP (801) and the UE (811). And T24 may be the reception time from the first TRP (801) to the UE (812).

[0176] As previously explained, the PL offset must be determined to avoid strong interference with neighboring cells, to address the location of uplink-only TRPs that do not transmit any signals on the downlink, and to address reception failures due to uplink asynchrony. In addition, the sounding reference signal (SRS) transmitted by the UE on the uplink and / or the random access (RA) preamble and transmission timing (TT) offset transmitted by beam sweeping over the physical random access channel (PRACH) must be determined.

[0177] For convenience of explanation, the RA preamble may be referred to as a preamble in the following description. Therefore, unless specifically mentioned or distinguished from another preamble, the preamble in this disclosure may be understood as an RA preamble. However, it should be noted that this is merely an example, and any type of preamble may be used as long as it can perform the dynamic and procedural operations described below according to the present disclosure.

[0178] The third scenario in the asymmetric mTRP environment described in FIGS. 7a and 7b and the third-1 scenario in the asymmetric mTRP environment described in FIGS. 8a to 8c may be hereinafter referred to as “asymmetric uplink scenarios” as needed.

[0179] Figure 9 is a timing diagram for explaining a situation in which an asynchronous problem occurs in a UL-only TRP and the minimum absolute value of the asynchronous problem.

[0180] Referring to FIG. 9, the timing of transmission of downlink (DL) signals and the timing of transmission of uplink (UL) signals between a macro TRP (MTRP) (901), a UL-only TRP (902), and a UE (903) are exemplified. First, the MTRP (901) and the UL-only TRP (902) can be spaced apart by A meters, and the MTRP (901) and the UE (903) can be spaced apart by B meters.

[0181] First, the timing when a DL signal is transmitted will be described. MTRP (901) can transmit a DL signal to UE (903) at a point in time in absolute time. At this time, the DL signal transmitted by MTRP (901) can be received by UE (903) with a first time delay (τ1) of reference number 911 from absolute time. In addition, the DL signal transmitted by MTRP (901) can be received by UL-only TRP (902) with a second time delay (τ2) of reference number 912 from absolute time.

[0182] Next, the first timing when the UE (903) transmits an UL signal to the MTRP (901) is described.

[0183] The UE (903) can transmit a UL signal to the MTRP (901) via the UL-only TRP (902) at any point in time, for example, as early as the first TA (TA1) set by the MTRP (901). The first TA (TA1) value can be set based on the TA value set by the MTRP (901) for the UE (903) to transmit a UL signal to the MTRP (901). Reference numeral 921 can correspond to twice the first time delay (τ1). In addition, reference numerals 922 and 923 can be first time delays (τ1) that are half of TA1 in absolute time. Reference numeral 924 can be a second time delay (τ2) until the UL signal transmitted by the UE (903) is received by the UL-only TRP (902). Therefore, reference numeral 925 represents the TA offset (Δ) which is the difference between the first time delay (τ1) and the second time delay (τ2). TA ) may be.

[0184] Next, the second timing in which the UE (903) transmits the UL signal to the uplink-only TRP (902) is described.

[0185] The UE (903) can transmit a UL signal to the UL-only TRP (902) at any point in time, for example, earlier than the second TA (TA2) value set between the UE (903) and the UL-only TRP (902). Reference numeral 931 may be a second time delay (τ2) from the point in time earlier than the second TA (TA2) value to absolute time. Reference numeral 933 may be a first time delay (τ1) value corresponding to half of TA1 in absolute time. Therefore, the TA2 value may be determined as the sum of the first time delay (τ1) and the second time delay (τ2). In this case, the TA offset (Δ) which is the difference between the first time delay (τ1) and the second time delay (τ2) TA ) is the absolute value of the time (T) at which CP is transmitted. CP ) may be asynchronous if it is greater than 1 / 2 of the total.

[0186] Therefore, to prevent desynchronization in the UL-only TRP (902), the UE (903) must transmit UL signal to the UL-only TRP (902) at a time point earlier than TA2, and the TA2 value is T compared to TA1, which is the TA value between the MTRP (901) and the UE (903). CP TA offset (Δ) equal to 1 / 2 of TA ) should be transmitted at an early point in time.

[0187] The method described above may be a case where the UE (903) can use a first TA (TA1) value, which is time information for transmitting a UL signal to the MTRP (901), and a second TA (TA2) value, which is time information for transmitting a UL signal to the UL-only TRP (902). If the UE (903) cannot use two TA values ​​to resolve uplink asynchronization, that is, if the UE (903) can use only a single TA value, when it needs to transmit an SRS to the MTRP (901) to determine a PL offset or when it needs to transmit a UL signal to the UL-only TRP (902), an UL asynchronization (out-of-synchronization, OOS) problem may occur between the UE (903) and the UL-only TRP (902).

[0188] In an asymmetric scenario where there is one MTRP (901), one UE (903), and one UL-only TRP (902), reference numeral 925 may indicate a situation where an OOS occurs in the UL-only TRP (902). In addition, as described above, to prevent OOS, the transmission timing (TT) point based on the TA2 value is "TA1 - Δ TA " should be, Δ TA is T CP It must have a value greater than 1 / 2 of .

[0189] Below, a method is described to address the excessive uplink receive power and the location of unknown uplink-only TRPs and uplink desynchronization issues described in the third scenario in an asymmetric mTRP environment such as FIGS. 7a and 7b.

[0190] FIG. 10a is a flowchart for explaining an initial connection procedure of a UE in a third scenario in an asymmetric mTRP environment, and FIG. 10b is a flowchart for explaining an uplink transmission of a UE in a third scenario in an asymmetric mTRP environment.

[0191] The procedures of FIGS. 10A and 10B may be a continuous procedure in which the procedure of FIG. 10B is performed after the procedure of FIG. 10A, or each of FIGS. 10A and 10B may be performed separately. In the present disclosure, for convenience of explanation, it is assumed that the procedure of FIG. 10B is a continuous procedure in which the procedure of FIG. 10A is performed after the procedure of FIG. 10B. In addition, in the following explanation, a network according to the third scenario in an asymmetric mTRP environment may be configured with a first TRP, which is a macro TRP, a plurality of UEs (UE #0, ..., UE #U-1), and UL-only TRPs (UL-only TRP #1, ..., UL-only TRP #M). In addition, in the following explanation, for convenience of explanation, the operation of UE #0 among the UEs will be described as an example. In addition, the operations of the dedicated TRP #1 and the UL-only TRP #M among the UL-only TRPs will be described as examples.

[0192] First, referring to FIG. 10A, step S1000 may be an initial access setup procedure. In step S1001, a first TRP, which is a macro TRP, may transmit (or broadcast) beamformed SSBs in each of a plurality of directions. Accordingly, UE #0 may receive beamformed SSBs in multiple directions from the first TRP. UE #0 may perform downlink synchronization using one of the received SSBs. The SSBs transmitted by the first TRP may be transmitted periodically or aperiodically for initial synchronization and maintenance of a beamforming-based downlink. If beamforming is not used, the first TRP may transmit (or broadcast) one or more SSBs through a specific frequency band. For example, when transmitting (or broadcasting) SSH in the sub-6GHz band, the first TRP may simply transmit (or broadcast) one quasi-omni or multiple SSBs with a given directionality without using beamformed SSBs.

[0193] In step S1002, UE #0 may be in a downlink-synchronized state using a single SSB. UE #0 may obtain MIB information transmitted within the SSB on which downlink synchronization was performed. The MIB may be transmitted to UE #0 on a physical broadcast channel (PBCH). For UE #0 performing an initial access setup procedure, the MIB may correspond to the first system information acquired by UE #0 and may also be referred to as the first RRC message. The MIB may indicate location information of the time resource and frequency resource on which SIB1 is transmitted.

[0194] In step S1003, the first TRP, which is a macro TRP, may periodically broadcast SIB1. In step S1003, UE #0 may receive SIB1 transmitted from the first TRP based on information acquired from the MIB. Here, SIB1 may be transmitted to the UE on a physical downlink shared channel (PDSCH). SIB1 may correspond to the second system information acquired by the UE and may be referred to as a second RRC message.

[0195] The first TRP may transmit other SIB(s) besides SIB1 to the UE(s) during the initial access procedure via the PDSCH. If the first TRP wishes to transmit other SIB(s) via the PDSCH on which the SIB is transmitted, the first TRP may transmit scheduling and control information for SIB2 together with the SIB1 transmitted via the PDSCH to inform the UE(s) that the other SIB(s) are included consecutively in SIB1. In this way, SIB2 may also be transmitted via the PDSCH, including scheduling and control information for SIB3. This may be indicated in the same manner up to SIB y, which the first TRP wishes to transmit.

[0196] If the initial access procedure is to be performed quickly, the first TRP may not transmit multiple SIBs other than SIB1 during the initial access phase. If SIBs other than SIB1 are not transmitted during the initial access procedure, the first TRP may transmit control information via PDSCH notifying that multiple SIBs other than SIB1 will not be transmitted to SIB1. Information about multiple SIBs other than SIB1 may be transmitted in whole or in part in SIBy after the initial access procedure is completed, when UE #0 is in an RRC connected state, or during the process of completing RRC reconfiguration after the first TRP transmits RRC reconfiguration indication information to UE #0. Information about SIBs other than SIB1 may be requested by UE #0 to the first TRP, and the first TRP may transmit information about SIBs other than SIB1 to UE #0 in response to the request of UE #0. In the present disclosure, for convenience of explanation, it is assumed that only SIB1 is acquired during the initial access phase. However, this is only for the convenience of explaining the present disclosure, and the present disclosure is not limited thereto.

[0197] UE #0, which has received system information, for example, MIB and SIB, from the first TRP through steps S1001 to S1003, may perform a random access procedure. Step S1010 included in step S1000 may be a contention-based random access setup procedure. The RA procedure may be divided into a contention-based RA (CBRA) procedure and a contention-free RA (CFRA) procedure. During the initial access procedure, the UE may perform a CBRA procedure.

[0198] In step S1011, UE #0 can randomly select one preamble from all preambles provided by the first TRP and transmit the selected preamble to the first TRP via PRACH. In the 3GPP 5G NR standard, the preamble is also expressed as the first message (Msg1). At this time, the beam direction can be transmitted in the uplink direction corresponding to the beam direction in which the SSB is received in the downlink (reciprocal). The resource in which the preamble is transmitted can be determined based on the association information between the SSB and the RACH obtained from SIB1 in advance (e.g., RACH occasion (RO)). Here, RO can mean a specific time slot in which the RACH can be transmitted. In long-term evolution (LTE) / 5G NR, RACH transmission is possible in various subframes or slots, so RO can mean a specific timing and frequency resource in which the RACH message can be transmitted. The RO may indicate an opportunity for a RACH sequence to be transmitted at a specific time, which may be provided to the UE using system information (e.g. SIB1) broadcast by the first TRP (or the network (e.g. base station)).

[0199] RACH can be transmitted using specific frequency resources, and the specific frequency resources can be indicated (or designated) by the first TRP (or network). Therefore, the UE can transmit the RACH message in the frequency and time slot indicated by the first TRP. The RACH can be used in common by all UEs, and if all UEs randomly attempt the RACH, collisions may occur between the RACHs transmitted by each UE. Therefore, RO may be intended to reduce such collisions and increase the efficiency of the RACH process. Since the UE can transmit a RACH request at a time precisely synchronized with the first TRP through RO, network resources can be used more efficiently. In summary, RO may refer to a specific time and frequency resource where the RACH procedure can occur in LTE / 5G NR. RO may be an important factor in helping the UE efficiently access the base station.

[0200] The first TRP can detect whether a preamble is transmitted from the UE(s) based on SIB1-related information (e.g., RO) in step S1011. The preamble can inform the first TRP of the presence of a UE requiring uplink synchronization, and can also be used to estimate the propagation delay time between the UE and the first TRP.

[0201] Meanwhile, in step S1011, when UE #0 transmits a preamble, it cannot know in advance the transmission power of the appropriate preamble. Therefore, UE #0 can estimate the required power based on the PL measured through the downlink and the transmission power information of the first TRP obtained from SIB1, and then determine the transmission power of the preamble based on the estimated value. In addition, UE #0 can set a window for receiving a response signal from the first TRP after transmitting Msg1. The response signal received from the first TRP may be a random access response (RAR), and the window for receiving the response signal may be referred to as an RAR window. If the RAR is not received from the first TRP within the time set in the RAR window, UE #0 may determine that the transmission of Msg1 has failed. Then, UE #0 can retransmit the preamble by setting the transmission power of the preamble to a higher value.

[0202] In step S1012, the first TRP can determine whether a preamble exists in a signal received via the PRACH. As described in step S1011, since the preamble is randomly selected and transmitted by UE #0, it is not possible to determine which UE transmitted which preamble based on whether a preamble is detected. Therefore, even if a preamble is detected in the RO, the first TRP cannot determine how many UEs used the detected preamble. In step S1012, the first TRP can generate an RAR based on the index of the detected preamble. The RAR can be scrambled with a random access radio network temporary identifier (RA-RNTI) and transmitted to the UE via a physical downlink control channel (PDCCH).

[0203] UE #0 and the first TRP can calculate the RA-RNTI based on the time / frequency resource location of the RO where the preamble was transmitted. At this time, the scheduling information of the PDCCH is mapped to the common search space (CSS) information within SIB1 acquired by UE #0 in advance. The PDCCH time / frequency resource location is not fixed, but is located at a single location within the CSS search space. Therefore, UE #0 must blindly decode the PDCCH for locations within the CSS to determine this location. Blind decoding of the PDCCH may increase the power consumption of the UE.

[0204] The RAR may include an RA preamble identifier (RAPID), a timing advance / adjustment / alignment command (TAC), an UL grant, a temporary cell radio network temporary identifier (TC-RNTI), a timing advance / adjustment / alignment (TA) group (TAG) identifier (ID), and an Asym indicator.

[0205] Here, TAC may mean a value for correcting the estimated time error when the first TRP receives Msg1 for UL synchronization, and UL grant may mean information indicating UL resources allocated for UE #0 to transmit the third message (message 3, Msg3) to be described in step S1013 below to the first TRP. TC-RNTI is an RNTI temporarily issued to UE #0 and may be used for transmission and reception of Msg3 and the fourth message (message 4, Msg4) to be described in step S1014 below. In addition, TAG ID may be an ID related to the transmission time of the UL signal transmitted by UE #0 through the link between UE #0 and the first TRP.

[0206] The TAG ID may be set to the default value of 'zero (0)' when UE #0 first performs step S1012 of the CBRA procedure. On the other hand, if step S1012 of the CBRA procedure is not for the serving cell, the value of the TAG ID may be set to '1' to indicate that it is not the serving cell. In addition, the TAG ID of step S1012 may be the same as or different from the TAG ID in the UL transmission configuration indicator (TCI) state message.

[0207] The Asym indicator may be a field for UE #0 to recognize that step S1012 of CBRA is applied to an asymmetric uplink scenario as described in FIG. 7a or as described in FIG. 8a. The Asym indicator field may consist of 1 bit. For example, if the Asym indicator field value is 'zero (0)', it may mean that it is not an asymmetric deployment scenario, and if the Asym indicator field value is '1', it may mean that step S1012 of CBRA is applied to an asymmetric deployment scenario. In this case, the field value is an example and may be set to be interpreted in the opposite way.

[0208] The TAG ID can be reused to indicate one of two TA values. More specifically, if the TA value estimated in step S1011 of CBRA is not out-of-synchronization between the first TRP and UE #0, the TAG ID value can be set to '0' to use the TA value between the first TRP and UE #0 for reverse transmission. On the other hand, if the first TRP and UE #0 are out-of-synchronization, the TAG ID value can be set to '1' to use the TA value between the first TRP and UE #0 minus the TA offset value for reverse transmission.

[0209] Additionally, the 1-bit TAG ID field of Rel-18 RAR can be used to differentiate between the first link (corresponding to TAG ID 0) where UE #0 is connected to the first TRP which is a macro TRP, and the second link (corresponding to TAG ID 1) where UE #0 is connected to the uplink-only TRP. Additionally, the 1-bit TAG ID field of Rel-18 RAR can be specified in the MAC-CE message for the activated / indicated joint / UL TCI state in the Unified TCI framework.

[0210] The purpose of supporting two TAs in an asymmetric scenario in Rel-19 may be to distinguish whether the difference in TA values ​​between the first and second links is within the OOS range. If the purpose of distinguishing whether the difference in TA values ​​between the first and second links is within the OOS range is followed, the TAG ID defined in Rel-18 may not be suitable for use as is in Rel-19. This is because, if the TA value of the second link is almost the same as the TA value of the first link, it is desirable to map the second link to TAG ID 0 corresponding to the TA value of the first link. However, this mapping is not possible in Rel-18 due to the support of coresetPoolIndex. To address this, it may be proposed to add a new 1-bit asynchronous (Asym) indicator field to the RAR message and MAC-CE message in Rel-19. If the bit of the Asym indicator field proposed in this disclosure is set to '0', UE #0 shall support the 2 TA extension in Rel-18 for the TAG ID. When the Asym indicator field bit is set to '1', it may be permissible to map TAG ID 0 to the second link if the TA values ​​of the two links are nearly identical. This approach has the advantage of reducing resource waste in the absolute TAC command transmitted by the first TRP to UE #0 via MAC-CE to update the UL synchronization of UE #0. The summary according to the present disclosure is as follows:

[0211] ● A new 1-bit field can be specified in the RAR message and MAC-CE format for the enabled / indicated UL / Joint TCI state in the Unified TCI Framework.

[0212] > Bit field index 0 in this field may indicate that the 2 TA extensions in Rel-18 for TAG ID are supported.

[0213] > Bit field index 1 of this field may indicate that the TAG ID may be set to the same or different depending on the difference in TA values ​​of the connected links.

[0214] In step S1013, UE #0 can transmit an RRS setup request (RSR) message and an ID (hereinafter, UE ID) that can identify UE #0 to the first TRP using the uplink radio resources indicated by the UL grant included in the previously received RAR. At this time, the RSR message and the UE ID can be scrambled with TC-RNTI and transmitted through a physical uplink shared channel (PUSCH). Accordingly, the first TRP can receive the RSR message and UE ID scrambled with TC-RNTI from UE #0 through the PUSCH. In step S1013, if more than one UE transmitted the same preamble in step S1011 described above, that is, if a preamble collision occurs, all UEs that transmitted the same preamble can refer to the same RAR and utilize the same radio resources to transmit the RSR message and their UE IDs scrambled with TC-RNTI. In other words, a collision of Msg3 may occur when two or more UEs transmit Msg3 to the first TRP.

[0215] All UEs that transmitted the same preamble in step S1011 will eventually transmit Msg3 in step S1013, and collisions may occur between these Msg3s. Each UE may start a contention resolution timer when transmitting Msg3 to the first TRP to determine whether its transmitted Msg3 experienced a collision or was successfully decoded in the first TRP.

[0216] Step S1014 may be the second procedure for resolving contention. In step S1014, the first TRP may decode the received Msg3 and transmit a contention resolution identity (CRI) message for the successfully decoded message to UE #0 via the CRI MAC-CE of the PDSCH. If Msg3 is successfully decoded, the first TRP may transmit Msg4, which includes uplink grant information for UE #0, to UE #0, thereby performing a normal transmission process between UE #0 and the first TRP. In addition, Msg4 may include a message for RRC setup and may be transmitted to UE #0 via the PDSCH.

[0217] If UE #0 receives a CRI message before the expiration of the contention resolution timer started in step S1013, UE #0 may consider (or determine) that the RA procedure has been successfully performed. Then, UE #0 may consider the TC-RNTI as its C-RNTI for continued use in the system connected state.

[0218] If the CRI message is not received before the contention resolution timer started in step S1013 expires or the CRI message received before the contention resolution timer expires is not the same, UE #0 may determine that the transmission of Msg3 in step S1013 has failed. If UE #0 determines that the transmission of Msg3 has failed, it may perform a backoff and retry the 4-step CBRA setup procedure. In other words, it may start again from step S1011.

[0219] The first TRP defines the maximum number of RA attempts to prevent RACH channel congestion, and if a random access is not successful during the maximum number of attempts, the UE may abandon the RA procedure and perform it again from the downlink synchronization.

[0220] In step S1021, UE #0, which successfully completes the RA procedure, can transmit a hybrid automatic repeat and request (HARQ) ACK / NACK message as a response to whether the message was properly received to the first TRP via PUCCH. In addition, UE #0 can transmit a registration request to the access and mobility management function (AMF) via a non-access stratum (NAS) layer. Here, the NAS layer may be a layer for signaling between UE #0 and the core network, not for signaling between UE #0 and the first TRP. Thereafter, authentication and security procedures can be performed via the NAS layer, and a registration accept message can be transmitted from the AMF to UE #0 via the first TRP.

[0221] In step S1022, the first TRP may transmit an RRC reconfiguration message to UE #0 together with the registration acceptance message received from the AMF. Accordingly, UE #0 may receive the registration acceptance message from the AMF and the RRC reconfiguration message from the first TRP.

[0222] In step S1023, UE #0 may transmit an RRC reconfiguration complete and registration complete message to the first TRP. Thereafter, UE #0 may enter an RRC connected state capable of transmitting and receiving data to the first TRP.

[0223] Figure 11 is a conceptual diagram for explaining a case where UE has completed RRC setup with the first TRP in the third asymmetric mTRP scenario.

[0224] Referring to FIG. 11, a base station (1141) can communicate with a UE (1111) located within its cell using multiple TRPs (1101, 1102, 1103). In the example of FIG. 11, only three TRPs (1101, 1102, 1103) are illustrated for the sake of simplicity of the drawing, but the number of TRPs that can be included in the base station (1141) is not limited to three. In other words, the base station (1141) may include only one TRP, or two TRPs, or four or more TRPs. However, since the present disclosure describes an mTRP environment, the case where only one TRP is included in the base station (1141) is not considered.

[0225] In the embodiment of FIG. 11, it is assumed that three different TRPs are included in one base station (1141). A first TRP (1101) may have a first cell area (1110), a second TRP (1102) may have a second cell area (1120), and a third TRP (1103) may have a third cell area (1130). As illustrated in FIG. 11, the first cell area (1110) formed by the first TRP (1101) may be a cell having the widest area, and further, the first cell area (1110) may include both the second cell area (1120) and the third cell area (1130).

[0226] The first TRP (1101) illustrated in FIG. 11 may be referred to as a macro TRP or head TRP as described above, and may perform downlink (DL) and uplink (UL) transmissions with the UE (1111). Additionally, the second TRP (1102) and the third TRP (1103) may be uplink-only TRPs as described above. Accordingly, the second TRP (1102) and the third TRP (1103) may be TRPs that do not transmit any signals in the downlink or may be TRPs that transmit only minimal downlink signals.

[0227] The UE (1111) illustrated in FIG. 11 may be UE #0 described in FIG. 10A, and may have performed the first TRP and step S1000. Furthermore, the UE (1111) illustrates a case in which it transmits an RRC reconfiguration complete message in step S1023 after performing steps S1021 and S1022. In other words, the UE (1111) illustrated in FIG. 11 may be an example of a case in which it transmits an RRC reconfiguration complete message to the first TRP (1101) and enters an RRC connected state.

[0228] Next, referring to FIG. 10b, the procedure for UE #0 to perform uplink transmission is described. FIG. 10b is a flowchart for uplink transmission by a UE in the third scenario in an asymmetric mTRP environment, and thus, the first TRP may be a macro TRP or a head TRP. Furthermore, UE #0 may be in an RRC-connected state with the first TRP, as described in FIG. 10a. Furthermore, other TRPs other than the first TRP may be UL-only TRPs.

[0229] Although not illustrated in FIG. 10b, prior to performing FIG. 10b, the first TRP and UE #0 may perform procedures necessary for path loss (PL) calculation. To address the problem of strong uplink interference to / from adjacent cells and reception failure due to unknown UL-only TRP location and uplink out-of-sync (OOS) occurring in Scenario 3 in an asymmetric mTRP environment, the first TRP may broadcast a PL reference signal (PL-RS) when necessary and / or periodically. Then, UE #0 may receive the PL-RS from the first TRP. UE #0 may calculate DL PL from the first TRP to the UE using the PL-RS received from the first TRP.

[0230] The procedure of Fig. 10b is explained assuming that UE #0 has calculated DL PL as above. However, the procedure of Fig. 10b can also be performed if UE #0 has not calculated DL PL.

[0231] In step S1030, the first TRP may command (or instruct) UE #0 to beam sweep the SRS or the preamble. Accordingly, UE #0 may receive a signal from the first TRP commanding (or instructing) to transmit the SRS or the preamble by beam sweeping. Various signals may be used as the signal commanding (or instructing) to beam sweep the SRS or the preamble. For example, any of the downlink control information (DCI) used in the current 5G NR standard may be used, or a newly defined message may be used. The use of DCI as a signal commanding (or instructing) to beam sweep the SRS or the preamble is only one embodiment, and the present disclosure is not limited thereto. For example, an RRC signaling message may instruct transmission at specific time periods, or if two or more periods are set by the RRC signaling message, a Media Access Control-Control element (MAC CE) may instruct one time period to be activated.

[0232] In step S1040, UE #0 may transmit SRS or preamble by beam sweeping in predefined (or preset) directions based on a command from the first TRP. Since it is not known which TRP among UL-only TRP #1, ..., UL-only TRP #M the SRS or preamble transmitted by UE #0 in step S1040 is received in, it should be noted that in FIG. 10b, the signal in step S1040 is illustrated as being transmitted in duplicate to UL-only TRPs.

[0233] At this time, UE #0 can use the transmit power of the SRS or preamble as is, calculated from the PL-RS and DL PL to the first TRP. As another example, UE #0 can use the transmit power of the SRS or preamble as is, calculated from the transmit power applied by UE #0 in step S1013 during the RA procedure. As another example, UE #0 can use the transmit power of the SRS or preamble by modifying the transmit power applied by UE #0 in step S1013 during the RA procedure. UE #0 can transmit a UL physical signal (or UL physical channel) that is spatially related to the first TRP (or beamformed to the first TRP).

[0234] Additionally, since UE #0 does not know the location of the UL dedicated TRP(s), it can transmit UL signal(s) beam-sweeped in predefined directions with the transmit power described above. Alternatively, UE #0 can transmit SRS or preamble with the same transmit power as the (initial) transmit power received from the first TRP. Alternatively, UE #0 can transmit SRS or preamble with modified power. Therefore, the UL signal used for beam-sweeping can be either SRS or PRACH preamble, and one of the beam-swept signals can be transmitted in the direction of the first TRP.

[0235] Before UE #0 performs beam sweeping, the first TRP may command UE #0 to perform beam sweeping according to given conditions (e.g., number of UL signals to be beam swept per set, transmission timing per set, etc.) using UL's SRS and / or preamble.

[0236] Each of the UL-only TRPs (UL-only TRP #1, …, UL-only TRP #M) can calculate UL receive power and receive timing based on the spatial SRS / preamble associated with the UE from UE #0 in step S1040.

[0237] In steps S1051 and S1052, each of the UL-only TRPs (UL-only TRP #1, …, UL-only TRP #M) can transmit the UL receive power and receive timing based on the spatial SRS / preamble associated with the calculated UE to the first TRP, which is a macro TRP (or head TRP). Accordingly, in steps S1051 and S1052, the first TRP, which is a macro TRP (or head TRP), can receive the UL receive power and receive timing based on the spatial SRS / preamble associated with the UE from each of the UL-only TRPs (UL-only TRP #1, …, UL-only TRP #M).

[0238] The first TRP may determine one or more UL-only TRPs based on UL receive power and receive timing based on spatial SRS / preambles associated with the UE received from each of the UL-only TRPs.

[0239] In step S1060, the first TRP may transmit to the UE (e.g., UE #0) mapping information between PL offset, TT offset, PL / TT offset and UL TCI associated with one or more UL-only TRPs determined for the UE. Accordingly, UE #0 may receive mapping information between PL offset, TT offset, PL / TT offset and UL TCI associated with one or more UL-only TRPs from the first TRP in step S1060.

[0240] Although step S1060 is illustrated as a single step in FIG. 10b, it may actually consist of two or three steps based on the description below. Briefly, for example, it may be transmitted by an RRC message, a MAC CE message, or a DCI. If the information described below is transmitted to UE #0 via one or both of the RRC message and / or the MAC CE message received before step S1060, the instructions to perform steps S1071 and S1072 may be instructed by the DCI.

[0241] In steps S1071 and S1072, UE #0 can transmit uplink data to each of the UL-only TRPs (UL-only TRP #1, …, UL-only TRP #M). In the example of FIG. 10b, it is assumed that the number of UL-only TRPs determined for UE #0 is two or more. However, the first TRP may determine only one UL-only TRP for a specific UE, or may determine two or more UL-only TRPs for a single UE as illustrated in FIG. 10b.

[0242] Figure 12 is a conceptual diagram for explaining a case where a UE transmits an uplink signal by beam sweeping in a third scenario in an asymmetric mTRP environment.

[0243] Referring to FIG. 12, a base station (1241) can communicate with a UE (1211) located within its cell using multiple TRPs (1201, 1202, 1203). In the example of FIG. 12, only three TRPs (1201, 1202, 1203) are illustrated for the sake of simplicity of the drawing, but the number of TRPs that can be included in the base station (1241) is not limited to three. In other words, the base station (1241) may include only one TRP, or two TRPs, or four or more TRPs. However, since the present disclosure describes an mTRP environment, the case where the base station (1241) includes only one TRP is not considered.

[0244] Also, in the embodiment of FIG. 12, it is assumed that three different TRPs are included in one base station (1241). The first TRP (1201) may have a first cell area (1110), the second TRP (1202) may have a second cell area (1220), and the third TRP (1203) may have a third cell area (1230). The first TRP (1201) illustrated in FIG. 12 may be referred to as a macro TRP or head TRP as described above, and may perform downlink (DL) and uplink (UL) transmission with the UE (1211). In addition, the second TRP (1202) and the third TRP (1203) may be uplink-only TRPs as described above. Therefore, the second TRP (1202) and the third TRP (1203) may be TRPs that do not transmit any signal in the downlink or TRPs that transmit only a minimal downlink signal.

[0245] The UE (1211) illustrated in FIG. 12 may be UE #0 described in FIGS. 10A and 10B and may be in an RRC-connected state with the first TRP (1201). The UE (1211) may be instructed to transmit an SRS or a preamble from the first TRP (1201). The UE (1211) may transmit the SRS or the preamble based on the number of UL signals beam-swept per set and the transmission time per set indicated by the first TRP (1201) among the beam directions that the UE (1211) can set, as illustrated in FIG. 12.

[0246] The example of FIG. 12 may be a diagram corresponding to step S1040 described in FIG. 10b above. As illustrated in FIG. 12, at least one UL-only TRP(s) that has received an SRS or preamble transmitted by a UE (1211) may provide received power information to the first TRP (1201) and / or the base station (1241). The first TRP (1201) and / or the base station (1241) may determine a PL offset value to address the problem of excessive uplink reception power as mentioned above. Determination of the PL offset value is described in more detail below.

[0247] Here, if the carrier frequency used by the first TRP (1201) / base station (managing the first TRP) (1241) / network (NW-managing the base station) (not shown in FIG. 12) and the UE (1211) belongs to FR2 (e.g., 24.25 to 52.6 GHz) and FR2-1 (e.g., 52.6 to 71 GHz) of 6 GHz or more, the unknown UL-only TRP problem and the OOS problem mentioned above may occur simultaneously because the path loss is large and beamforming is generally used.

[0248] Additionally, if the carrier frequency used by the UE (1211) falls within the FR1 (e.g., 0.41 to 6 GHz) below 6 GHz, beamforming may not be used. If beamforming is not used, only the OOS problem among the two problems mentioned above may occur. Depending on the type of UL signal(s) that the UE (1211) sends to the UL-only TRPs to calculate the PL offset values ​​mentioned above, either all or one of the problems described above may occur.

[0249] When the carrier frequency used by the first TRP (1201) / base station (managing the first TRP) (1241) / NW (managing the gNB) (not shown in FIG. 12) and the UE (1211) belongs to FR1 of, for example, 6 GHz or less (e.g., 0.41 to 6 GHz), the UE (1211) can transmit a signal / channel by forming a beam pattern in a quasi-omnidirectional manner without knowing the locations of the surrounding UL-only TRPs. Therefore, the unknown UL-only TRP problem mentioned above can be solved to some extent. However, the OOS problem mentioned above may depend on what kind of UL signal(s) the UE transmits to the UL-only TRPs in order to calculate the PL offset values ​​mentioned above.

[0250] Below, the procedure for determining PL offset value(s) depending on whether the UL signal(s) are in the form of SRS or PRACH preamble and the operation up to SRS and / or preamble transmission will be described.

[0251] In a situation where a UE can form a quasi-omnidirectional transmission beam pattern in a FR1 frequency band and / or a directional transmission beam pattern in a FR2 and FR2-1 frequency band, let us assume that the UL signal(s) to be transmitted by the UE are SRS. Then, the UE can transmit SRS for at least one of channel state information (CSI), uplink beam management, PL offset, TT offset determination, TT offset estimation, or TT offset collection through one embodiment described below.

[0252] First, the first TRP / base station (gNB) / network (NW) (hereinafter referred to as NW) can transmit at least one of RRC, MAC-CE, or DCI to the UE, and at least one of the RRC, MAC-CE, or DCI can include an SRS request field. The DCIs can instruct the UE to transmit an SRS. As described above, the SRS can be indicated by the DCIs as quasi-omnidirectional or directional. In addition, the SRS can be for CSI, uplink beam management, PL offset, TT offset determination, TT offset estimation, or TT offset collection.

[0253] Here, the SRS transmitted by the UE may be an SRS resource set, and the SRS resource set may be transmitted through time resources and frequency resources indicated by one resource configuration. However, in this case, the OOS problem mentioned above may occur. In addition, to solve the OOS problem, at least two SRS resource sets with different transmission times for transmitting the SRS may be transmitted through each of the two indicated time and frequency resource sets. To solve the unknown UL-only TRP problem mentioned above, one and / or two or more SRS resource sets(s) may include SRS resources beam-swept in multiple directions.

[0254] Meanwhile, at least one of RRC, MAC-CE or DCI may be configured with fields such as a PL offset determination indicator, a transmission point indicator, a transmission point value (or index) for CSI, uplink beam management, PL offset, TT offset determination, TT offset estimation or TT offset collection.

[0255] The PL Offset Determination Indicator field may consist of 1 bit. For example, if the bit information of the PL Offset Determination Indicator field is '1', it may mean that RRC / MAC-CE / DCI is for the first TRP, base station (gNB), or NW to determine the PL offset value(s) for UL-only TRP(s).

[0256] The transmission timing indicator field may consist of 1 bit. For example, if the bit information of the transmission timing indicator field is '0', it may mean that the transmission timing of the SRS resource set transmitted by the UE, in order for the NW to determine the PL offset value(s) for the UL-only TRP(s) by RRC / MAC-CE / DCI, follows the transmission timing when transmitting a signal (or channel) to the first TRP configured when establishing a connection between the first TRP and the UE as described in FIG. 10a. On the other hand, if the bit information of the transmission timing indicator field is '1', it may mean to transmit the SRS resource set(s) including transmission timings other than the transmission timing when the UE transmits a signal (or channel) to the first TRP. Here, if it is determined that the transmission timing indicator field can make the UE recognize that it is for determining the PL offset of the UL-only TRP by using one or more of the RRC, MAC-CE or DCI information, the NW may not use the PL offset determination indication field.

[0257] The transmission point value (or index) field may be used when the bit information of the transmission point indication field is '1'. When the bit information of the transmission point indication field is '1', the transmission point value (or index) field may mean to indicate transmission point value(s) (or index(es)) other than the transmission point when transmitting a signal (or channel) with the first TRP. If the transmission point indication field value itself means a transmission point value defined in advance in the standard, the transmission point value (or index) field may not be used.

[0258] For example, when two transmission points are used, the transmission points can be determined as follows. The first transmission point can mean a transmission point for transmitting a signal (or channel) to the first TRP configured when establishing a connection between the first TRP and the UE as described in FIG. 10a, and the second transmission point can mean a transmission point delayed by a TA offset from the transmission point for transmitting a signal to the first TRP. The reason for configuring the second transmission point is to enable UL-only TRPs closer to the UE than the first TRP to successfully receive (or estimate) the SRS resource set(s) without OOS.

[0259] The reason for configuring the first transmission point is to ensure that the UL-only TRPs around the first TRP can successfully receive (or estimate) the SRS(s). The target UL-only TRP(s) for configuring the first transmission point may include UL-only TRPs that generate more PL (e.g., 10 dB) than the PL between the UE and the first TRP in order to introduce a kind of UL offloading concept. In addition, UL-only TRPs that generate, for example, 60 dB more PL than the PL between the UE and the first TRP may also be target UL-only TRPs in order to introduce a kind of UL offloading concept. In order to satisfy the UL-only TRPs that generate 60 dB more PL, the NW may configure a third transmission point, i.e., a transmission point that is earlier than the transmission point when the UE sends to the first TRP.

[0260] Meanwhile, the NW can configure an SRS resource set for CSI, uplink beam management, PL offset, TT offset determination, TT offset estimation, or TT offset collection through DCIs including RRC, MAC-CE, or SRS request fields, and transmit the SRS resource set to the UE. The NW can instruct the UE to transmit SRS periodically, and the NW can instruct the UE to transmit the SRS semi-omni-directionally or directionally. As another example, the NW can instruct the UE to transmit a semi-persistent SRS, and the NW can instruct the UE to transmit the SRS semi-omni-directionally or directionally. As another example, the NW can instruct the UE to transmit an SRS aperiodicly, and the NW can instruct the UE to transmit the SRS semi-omni-directionally or directionally. The procedure for this will be further described below.

[0261] Additionally, the procedures for activating SRS resources, modifying SRS resources, reconfiguring SRS resources, and deactivating SRS resources will be described below.

[0262] First, for reference, to increase understanding, we will first explain the main functions of SRS.

[0263] SRS can be used to collect channel state information (CSI). SRS can be transmitted by the UE to the network (e.g., the base station (gNB)) to accurately determine the status of the uplink channel. The NW can perform important network tasks, such as beamforming, link adaptation, and resource allocation, through the SRS transmitted by the UE.

[0264] SRS can be used for frequency-selective scheduling. SRS can be transmitted across multiple frequency bands, allowing the network to evaluate the status of various frequency channels and select the optimal resource.

[0265] SRS can be used for uplink beam management. Combined with multi-antenna technology (Multi-Input and Multi-Output, MIMO), SRS can play a crucial role in determining the optimal beam direction in the uplink.

[0266] SRS can be used for UL synchronization tracking and asymmetric uplink PL and TT offset determination. Typically, the network can track and update uplink synchronization using SRS transmitted by the UE. Furthermore, in an asymmetric mTRP scenario where UL-only TRP(s) exist, the network can use it to determine PL offsets and TT offsets for UL power control and UL synchronization in UL-only TRP(s).

[0267] Next, the RRC message-related procedures related to SRS by the NW are described. The RRC message-related procedures related to SRS can be particularly useful when controlling periodic SRS transmissions.

[0268] (1) The network may transmit an RRC Reconfiguration message or an RRC Connection Reconfiguration message to the UE. The UE may receive the RRC Reconfiguration message or the RRC Connection Reconfiguration message transmitted by the network, and may check information such as the SRS transmission time, SRS frequency allocation, SRS transmission power, and beamforming settings from the SRS resource configuration (SRS-Config) information and field information for each SRS resource. The RRC Reconfiguration message or the RRC Connection Reconfiguration message may include a list of SRS resources to be added or modified.

[0269] The SRS Resource Configuration (SRS-Config) information element (IE) in RRC can be configured as follows. The RRC protocol can use the SRS-Config IE to configure the UE to transmit SRS. According to the current 5G NR specifications, the SRS-Config IE can include the following main fields:

[0270] - srs-ResourceSetToAddModList field: The srs-ResourceSetToAddModList field can define a set that groups multiple SRS resources. A resource set can contain multiple SRS resources and can be configured to transmit SRS at different frequency locations and times. The srs-ResourceSetToAddModList field can be mainly configured to allow the base station to collect SRS at specific times and frequency resources.

[0271] - srs-ResourceSetToReleaseList field: The srs-ResourceSetToReleaseList field may be a field for releasing previously set SRS resources. The srs-ResourceSetToReleaseList field may be used during RRC reset and may be used to remove SRS resources that are no longer needed.

[0272] - srs-ResourceToAddModList field: The srs-ResourceToAddModList field can be a field for adding a new SRS resource or modifying an existing SRS resource. The srs-ResourceToAddModList field can be used when the base station configures a new SRS resource to obtain additional channel information from the UE.

[0273] - aperiodicSRS-ResourceTrigger field: The aperiodicSRS-ResourceTrigger field can specify the code point of the DCI that transmits / triggers SRS according to the set of SRS resources configured by the UE.

[0274] - srs-PowerControl field: The srs-PowerControl field may have an alpha field for power control of SRS transmission, which may play a role in adjusting the transmission power of the UE according to path loss.

[0275] - Transmission comb and frequency domain configuration field: The transmission comb and frequency domain configuration field can configure resource mapping in the frequency domain of SRS, transmission comb, frequency hopping value, etc.

[0276] - SlotOffset field: The SlotOffset field can specify the time offset in slot units between the triggered DCI and the actual SRS transmission.

[0277] - Resource Type and Periodicity Fields: The Resource Type and Periodicity fields can define whether the SRS is periodic, aperiodic, or semi-persistent. The Resource Type and Periodicity fields can determine how often the UE transmits the SRS.

[0278] In the present disclosure, in order to allow a base station (gNB) to estimate the received power and received timing error required to determine PL offset and TT offset, etc., for UL-only TRP(s) in an asymmetric uplink scenario without out-of-synchronization, a "SampleOffset" field may be added to the SRS-Config IE defined in the current 5G NR. The SampleOffset field may specify a time offset in units of samples from the first sample of the start symbol of an actual SRS transmission. If the SampleOffset field consists of 1 bit, a bit value of '0' may mean an SRS transmission at a time point delayed by a TA offset (e.g., SampleOffset) from the uplink transmission time point with the first TRP.

[0279] When the SampleOffset field consists of 2 bits, a bit value of '00' may mean SRS transmission at the time of uplink transmission with the first TRP, a bit value of '01' may mean SRS transmission at the time delayed by TA offset 1 from the time of uplink transmission with the first TRP, a bit value of '10' may mean SRS transmission at the time delayed by (or earlier than) TA offset 2 from the time of uplink transmission with the first TRP, and a bit value of '11' may mean reserved.

[0280] Each SRS resource can have a separate configuration field, which can contain information about when, where, and how often the SRS will be transmitted. The field information for each SRS resource is as follows:

[0281] - srs-ResourceId field: The srs-ResourceId field can indicate a unique identifier (ID) for the corresponding SRS resource. The srs-ResourceId field can be used to distinguish a specific resource among multiple SRS resources.

[0282] - nrofSRS-Ports field: The nrofSRS-Ports field can define the number of antenna ports used for SRS transmission. More specifically, the nrofSRS-Ports field can set the number of antenna ports to be used in a multi-antenna or MIMO environment. For example, the nrofSRS-Ports field can have values ​​such as 1, 2, and 4, which is an important factor for multi-beamforming.

[0283] - resourceType field: The resourceType field is a field that defines the type of SRS resource, and can be classified as periodic, semi-persistent, and aperiodic. If the resourceType field is set to periodic, it can instruct the UE to transmit the SRS periodically, if the resourceType field is set to semi-persistent, it can instruct the UE to transmit the SRS according to a preset time interval, and if the resourceType field is set to aperiodic, it can instruct the UE to transmit the SRS aperiodicly as needed.

[0284] - transmissionComb field: The transmissionComb field can determine how SRS transmissions are arranged on the frequency. The transmissionComb field can be used in conjunction with combOffset to define how SRS will be transmitted on various frequency resources.

[0285] - cyclicShift field: The cyclicShift field can indicate a cyclic shift value to enable different SRS signals to share frequency resources. The cyclicShift field allows for efficient transmission of multiple SRSs without interference.

[0286] - frequencyPosition field: The frequencyPosition field may be a field that defines the position of the frequency band in which the SRS is transmitted. The frequencyPosition field may be used by the base station to collect channel state information in the desired frequency resources.

[0287] - frequencyShift field: The frequencyShift field can define a shift value in frequency when transmitting SRS. The frequencyShift field can be used to more efficiently place SRS signals in a specific frequency band.

[0288] - frequencyHopping field: The frequencyHopping field can be used to configure whether to use frequency hopping when transmitting SRS. Frequency hopping can be a technique to increase transmission reliability by using various frequency resources.

[0289] - groupOrSequenceHopping field: The groupOrSequenceHopping field can be used to vary the transmission frequency of the SRS using group or sequence hopping. The groupOrSequenceHopping field can be advantageous in reducing interference and securing frequency diversity.

[0290] - resourceMapping field: The resourceMapping field can define the time and frequency resource mapping of the SRS. The resourceMapping field can be composed of detailed parameters such as the symbol start (symbolStart), the number of symbols (numSymbols), and the number of subcarriers (numSubcarriers), and can determine in which symbol and subcarrier the SRS will be transmitted.

[0291] - srs-ConfigIndex field: The srs-ConfigIndex field can be an index that defines the period and transmission time interval of the SRS. Depending on the value of the srs-ConfigIndex field, the SRS can be transmitted periodically or aperiodically.

[0292] - srs-PeriodicityAndOffset field: The srs-PeriodicityAndOffset field can define the interval and start time at which SRS is transmitted periodically. For example, the srs-PeriodicityAndOffset field can instruct SRS to be transmitted at periods such as 20ms, 40ms, or 80ms.

[0293] - srs-TransmissionComb field: The srs-TransmissionComb field can determine how SRS resources are transmitted on the frequency. For example, the srs-TransmissionComb field can configure frequency resources differently through comb0 or comb1.

[0294] - antennaPorts field: The antennaPorts field can define the antenna port number through which the SRS is transmitted. The antennaPorts field is an important field in the multi-antenna configuration for beamforming. When multi-antenna transmission is supported, the SRS can be transmitted through multiple antenna ports, and the NW can measure the channel conditions in various beams through this. Here, the antennaPorts configuration can be different depending on the use of FR 1, FR 2, or FR 2-1. For example, when FR 1 is used, the antennaPorts field value can be set to match the quasi-omni-directional beam pattern (e.g., set one antenna port), and the SampleOffset field configuration can be used to resolve the OOS issue mentioned above. As another example, when FR 2 or FR 2-1 is used, the antennaPorts field value can be set to match the directional beam pattern (e.g., set multiple different antenna Ports), and both the unknown UL-only TRP and the OOS issue mentioned above can be resolved by using the SampleOffset field configuration.

[0295] - srs-PowerControl field: The srs-PowerControl field may be a power control setting used when transmitting SRS. The srs-PowerControl field may be used to adjust the appropriate transmission power to improve the quality of the signal received in the first TRP.

[0296] (2) The NW can activate and modify SRS resources. More specifically, the NW can trigger SRS transmission through an RRC message. If the SampleOffset field is not added to the RRCReconfiguration message or the RRCConnectionReconfiguration message, the SampleOffset field must be added to the RRC message for triggering SRS transmission. On the other hand, if the SampleOffset field is added to the RRCReconfiguration message or the RRCConnectionReconfiguration message, the SampleOffset field may or may not be added to the RRC message for triggering SRS transmission. The RRC message for triggering SRS transmission can dynamically modify, add, or release SRS resources. In addition, the RRC message for triggering SRS transmission can activate or deactivate SRS transmission according to network requirements. The UE may specify a reference signal (e.g., CSI-RS, SSB) used to estimate path loss for power control of SRS transmission.

[0297] (3) The UE can adjust the SRS transmission power according to the path loss reference and transmit the SRS according to the configured time domain settings (e.g., slot offset and periodicity).

[0298] (4) The base station (gNB) may send another RRCReconfiguration message to the UE to reconfigure or deactivate the SRS resources of the UE as needed.

[0299] Next, the procedures related to MAC-CE messages associated with SRS by the network are described.

[0300] The procedure for instructing and terminating SRS transmissions via MAC-CE is a crucial mechanism that allows the network to dynamically request or terminate SRS transmissions from the UE. This procedure can be particularly useful when controlling semi-persistent SRS transmissions. MAC-CE can perform these instructions through efficient control message exchange between the network and the UE. The procedures for instructing and terminating SRS transmissions via MAC-CE are as follows.

[0301] MAC-CE is a control message used at the MAC layer and can convey control commands, such as SRS triggering. MAC CE can be used to instruct or terminate SRS transmission by a UE, and can convey necessary control information very efficiently in a short message size. MAC-CE can include a trigger signal for SRS transmission, and the UE can receive the MAC-CE message and perform semi-persistent SRS transmission using the resources configured in the MAC-CE message. The procedure for instructing SRS transmission via MAC-CE is as follows:

[0302] (1) The network may transmit an RRCReconfiguration message or an RRCConnectionReconfiguration message to the UE. The UE may receive the RRCReconfiguration message or the RRCConnectionReconfiguration message transmitted by the network. The RRCReconfiguration message or the RRCConnectionReconfiguration message may check information such as the time of SRS transmission, frequency allocation, transmission power, and beamforming settings from the SRS-Config IE and field information for each SRS resource. The RRCReconfiguration message or the RRCConnectionReconfiguration message may include a list of SRS resources to be added or modified. The RRC protocol can use a message element called SRS-Config IE to configure the UE to transmit SRS, and the main fields of the SRS Resource Configuration (SRS-Config) IE in RRC according to the current 5G NR specifications are as follows:

[0303] - srs-ResourceSetToAddModList field: The srs-ResourceSetToAddModList field can define a set that groups multiple SRS resources. A resource set can contain multiple SRS resources and can be configured to transmit SRS at different frequency locations and times. The srs-ResourceSetToAddModList field can be mainly configured to allow the base station to collect SRS at specific times and frequency resources.

[0304] - srs-ResourceSetToReleaseList field: The srs-ResourceSetToReleaseList field may be a field for releasing previously set SRS resources. The srs-ResourceSetToReleaseList field may be used during RRC reset and may be used to remove SRS resources that are no longer needed.

[0305] - srs-ResourceToAddModList field: The srs-ResourceToAddModList field can be a field for adding a new SRS resource or modifying an existing SRS resource. The srs-ResourceToAddModList field can be used when the base station configures a new SRS resource to obtain additional channel information from the UE.

[0306] - aperiodicSRS-ResourceTrigger field: The aperiodicSRS-ResourceTrigger field can specify the code point of the DCI that transmits / triggers SRS according to the set of SRS resources configured by the UE.

[0307] - srs-PowerControl field: The srs-PowerControl field may have an alpha field for power control of SRS transmission, which may play a role in adjusting the transmission power of the UE according to path loss.

[0308] - Transmission comb and frequency domain configuration field: The transmission comb and frequency domain configuration field can configure resource mapping in the frequency domain of SRS, transmission comb, frequency hopping value, etc.

[0309] - SlotOffset field: The SlotOffset field can specify the time offset in slot units between the triggered DCI and the actual SRS transmission.

[0310] - Resource Type and Periodicity Fields: The Resource Type and Periodicity fields can define whether the SRS is periodic, aperiodic, or semi-persistent. The Resource Type and Periodicity fields can determine how often the UE transmits the SRS.

[0311] In the present disclosure, in order to allow a base station (gNB) to estimate the received power and received timing error required to determine PL offset and TT offset, etc. in an asymmetric uplink scenario for UL-only TRP(s) without out-of-synchronization, a "SampleOffset" field can be added to the SRS-Config IE currently defined in 5G NR. The SampleOffset field can specify the time offset in units of samples from the first sample of the start symbol of an actual SRS transmission.

[0312] Each SRS resource can have a separate configuration field, which can contain information about when, where, and how often the SRS will be transmitted. The field information for each SRS resource is as follows:

[0313] - srs-ResourceId field: The srs-ResourceId field can indicate a unique identifier (ID) for the corresponding SRS resource. The srs-ResourceId field can be used to distinguish a specific resource among multiple SRS resources.

[0314] - nrofSRS-Ports field: The nrofSRS-Ports field can define the number of antenna ports used for SRS transmission. More specifically, the nrofSRS-Ports field can set the number of antenna ports to be used in a multi-antenna or MIMO environment. For example, the nrofSRS-Ports field can have values ​​such as 1, 2, and 4, which is an important factor for multi-beamforming.

[0315] - resourceType field: The resourceType field is a field that defines the type of SRS resource, and can be classified as periodic, semi-persistent, and aperiodic. If the resourceType field is set to periodic, it can instruct the UE to transmit the SRS periodically, if the resourceType field is set to semi-persistent, it can instruct the UE to transmit the SRS according to a preset time interval, and if the resourceType field is set to aperiodic, it can instruct the UE to transmit the SRS aperiodicly as needed.

[0316] - transmissionComb field: The transmissionComb field can determine how SRS transmissions are arranged on the frequency. The transmissionComb field can be used in conjunction with combOffset to define how SRS will be transmitted on various frequency resources.

[0317] - cyclicShift field: The cyclicShift field can indicate a cyclic shift value to enable different SRS signals to share frequency resources. The cyclicShift field allows for efficient transmission of multiple SRSs without interference.

[0318] - frequencyPosition field: The frequencyPosition field may be a field that defines the position of the frequency band in which the SRS is transmitted. The frequencyPosition field may be used by the base station to collect channel state information in the desired frequency resources.

[0319] - frequencyShift field: The frequencyShift field can define a shift value in frequency when transmitting SRS. The frequencyShift field can be used to more efficiently place SRS signals in a specific frequency band.

[0320] - frequencyHopping field: The frequencyHopping field can be used to configure whether to use frequency hopping when transmitting SRS. Frequency hopping can be a technique to increase transmission reliability by using various frequency resources.

[0321] - groupOrSequenceHopping field: The groupOrSequenceHopping field can be used to vary the transmission frequency of the SRS using group or sequence hopping. The groupOrSequenceHopping field can be advantageous in reducing interference and securing frequency diversity.

[0322] - resourceMapping field: The resourceMapping field can define the time and frequency resource mapping of the SRS. The resourceMapping field can be composed of detailed parameters such as the symbol start (symbolStart), the number of symbols (numSymbols), and the number of subcarriers (numSubcarriers), and can determine in which symbol and subcarrier the SRS will be transmitted.

[0323] - srs-ConfigIndex field: The srs-ConfigIndex field can be an index that defines the period and transmission time interval of the SRS. Depending on the value of the srs-ConfigIndex field, the SRS can be transmitted periodically or aperiodically.

[0324] - srs-PeriodicityAndOffset field: The srs-PeriodicityAndOffset field can define the interval and start time at which SRS is transmitted periodically. For example, the srs-PeriodicityAndOffset field can instruct SRS to be transmitted at periods such as 20ms, 40ms, or 80ms.

[0325] - srs-TransmissionComb field: The srs-TransmissionComb field can determine how SRS resources are transmitted on the frequency. For example, the srs-TransmissionComb field can configure frequency resources differently through comb0 or comb1.

[0326] - antennaPorts field: The antennaPorts field can define the antenna port number through which the SRS is transmitted. The antennaPorts field is an important field in multi-antenna configuration for beamforming. When multi-antenna transmission is supported, the SRS can be transmitted through multiple antenna ports, which allows the network to measure the channel conditions in various beams. Here, the antennaPorts configuration can be different depending on the use of FR 1, FR 2, or FR 2-1. For example, when FR 1 is used, the antennaPorts field value can be set to match the quasi-omni-directional beam pattern (e.g., set one antenna port), and the SampleOffset field configuration can be used to resolve the OOS issue mentioned above. As another example, when FR 2 or FR 2-1 is used, the antennaPorts field value can be set to match the directional beam pattern (e.g., set multiple different antenna Ports), and the SampleOffset field configuration can be used to resolve both the unknown UL-only TRP and the OOS issue mentioned above.

[0327] - srs-PowerControl field: The srs-PowerControl field may be a power control setting used when transmitting SRS. The srs-PowerControl field may be used to adjust the appropriate transmission power to improve the quality of the signal received in the first TRP.

[0328] (2) When transmitting a semi-persistent SRS, the network can use a MAC-CE message to trigger (activate) SRS transmission to the UE. In other words, the network can instruct the UE to transmit the SRS using a specific SRS resource through the MAC-CE. The MAC-CE message can be transmitted together with or independently of the PUSCH transmission. The field information of the MAC-CE message for SRS triggering or activation can include an SRS resource ID, a trigger point, a transmission frequency range, etc. In this disclosure, a new field can be added to allow the gNB to estimate the received power and received timing error required for determining the PL offset and TT offset, etc. of the UL-only TRP(s) in an asymmetric uplink scenario without problems in OOS and unknown UL-only TRPs.

[0329] The present disclosure provides the ability to add a "SampleOffset" field to the MAC-CE for SRS triggering or SRS activation according to the current 5G NR standard. The SampleOffset field can specify a time offset in units of samples from the first sample of the start symbol of an actual SRS transmission.

[0330] When the SampleOffset field consists of 1 bit, a bit value of '0' in the SampleOffset field may mean SRS transmission at the time of uplink transmission with the first TRP, and a bit value of '1' in the SampleOffset field may mean SRS transmission at a time delayed by a TA offset (e.g., SampleOffset) from the time of uplink transmission with the first TRP.

[0331] When the SampleOffset field is composed of 2 bits, a bit value of '00' of the SampleOffset field may mean SRS transmission at the time of uplink transmission with the first TRP, a bit value of '01' of the SampleOffset field may mean SRS transmission at a time delayed by TA offset 1 from the time of uplink transmission with the first TRP, a bit value of '10' of the SampleOffset field may mean SRS transmission at a time delayed (or earlier) by TA offset 2 from the time of uplink transmission with the first TRP, and a bit value of '11' of the SampleOffset field may mean reserved. If the SampleOffset field is not added to the RRCReconfiguration message or the RRCConnectionReconfiguration message mentioned above, the MAC-CE according to the present disclosure must add the SampleOffset field. On the other hand, if a SampleOffset field is added to an RRCReconfiguration message or an RRCConnectionReconfiguration message, the MAC-CE according to the present disclosure may or may not add the SampleOffset field.

[0332] (3) The MAC-CE-based SRS transmission procedure is as follows. The UE can transmit SRS on the designated resources according to the trigger information transmitted in the MAC-CE. The SRS can be transmitted by utilizing the given frequency and time resources as indicated in the MAC-CE. The network can receive the SRS transmitted by the UE. The network can measure the UL channel status using the received SRS. The network can utilize the UL channel status measurement for resource scheduling and beamforming or for estimating the PL offset and TT offset.

[0333] If multi-antenna transmission is supported, SRS can be transmitted through multiple antenna ports, and the network can measure the channel conditions in various beams by receiving SRS transmitted through multiple antenna ports. Here, the SampleOffset field information among the trigger information transmitted by MAC-CE and SRS transmission through multiple antenna ports, i.e. beam-swept transmission, can solve the unknown UL-only TRP issue in beamforming mode.

[0334] (4) The procedure for terminating SRS transmission via MAC-CE is as follows. First, the network may indicate the termination of SRS transmission. When SRS transmission is no longer required, the network may use a MAC-CE message to instruct the UE to deactivate SRS transmission. In other words, the MAC-CE message may convey a command to terminate SRS transmission, and the UE may immediately deactivate SRS transmission after receiving the MAC-CE message. For example, the field information of the SRS deactivation MAC-CE message may include an SRS resource ID, a trigger point, a transmission frequency range, etc. Here, the SRS deactivation MAC-CE may also include the SampleOffset field described above.

[0335] (5) The RRC reconfiguration and transmission termination procedures are as follows. When the network needs to permanently stop SRS transmission or change SRS configuration, the network can transmit the new SRS configuration to the UE via an RRC Connection Reconfiguration (RRCConnectionReconfiguration) message and / or an SRS Triggering (or Activation) MAC-CE message. The network can instruct the UE to terminate the SRS transmission cycle, transmission resources, or the transmission itself via the RRC Connection Reconfiguration (RRCConnectionReconfiguration) message and / or the SRS Triggering MAC-CE message. When the SRS transmission is terminated or a new configuration is required, the network can inform the UE of the new configuration via an RRC message and / or an SRS Triggering (or Activation) MAC-CE message. In this case, the UE can stop or start the SRS transmission again depending on the new configuration.

[0336] Next, the procedures related to DCI messages related to SRS by the network are described. SRS requests via DCI can be primarily used to trigger aperiodic SRS transmissions. This allows the network to assess UL channel conditions in real time. The following describes the procedures for SRS resource allocation, SRS transmission, and SRS resource reallocation.

[0337] (1) The network may transmit an RRCReconfiguration message or an RRCConnectionReconfiguration message to the UE. The UE may check information such as the time, frequency allocation, transmission power, and beamforming settings of SRS transmission from the SRS-Config IE and field information for each SRS resource included in the RRCReconfiguration message or the RRCConnectionReconfiguration message received from the network. The RRCReconfiguration message or the RRCConnectionReconfiguration message may include a list of SRS resources to be added or modified. The RRC protocol may use the SRS-Config IE to configure the UE to transmit SRS, and the main fields included in the SRS-Config IE according to the current 5G NR standard are as follows:

[0338] - srs-ResourceSetToAddModList field: The srs-ResourceSetToAddModList field can define a set that groups multiple SRS resources. A resource set can contain multiple SRS resources and can be configured to transmit SRS at different frequency locations and times. The srs-ResourceSetToAddModList field can be mainly configured to allow the base station to collect SRS at specific times and frequency resources.

[0339] - srs-ResourceSetToReleaseList field: The srs-ResourceSetToReleaseList field may be a field for releasing previously set SRS resources. The srs-ResourceSetToReleaseList field may be used during RRC reset and may be used to remove SRS resources that are no longer needed.

[0340] - srs-ResourceToAddModList field: The srs-ResourceToAddModList field can be a field for adding a new SRS resource or modifying an existing SRS resource. The srs-ResourceToAddModList field can be used when the base station configures a new SRS resource to obtain additional channel information from the UE.

[0341] - aperiodicSRS-ResourceTrigger field: The aperiodicSRS-ResourceTrigger field can specify the code point of the DCI that transmits / triggers SRS according to the set of SRS resources configured by the UE.

[0342] - srs-PowerControl field: The srs-PowerControl field may have an alpha field for power control of SRS transmission, which may play a role in adjusting the transmission power of the UE according to path loss.

[0343] - Transmission comb and frequency domain configuration field: The transmission comb and frequency domain configuration field can configure resource mapping in the frequency domain of SRS, transmission comb, frequency hopping value, etc.

[0344] - SlotOffset field: The SlotOffset field can specify the time offset in slot units between the triggered DCI and the actual SRS transmission.

[0345] - Resource Type and Periodicity Fields: The Resource Type and Periodicity fields can define whether the SRS is periodic, aperiodic, or semi-persistent. The Resource Type and Periodicity fields can determine how often the UE transmits the SRS.

[0346] In the present disclosure, in order to allow a base station (gNB) to estimate the received power and received timing error required to determine PL offset and TT offset, etc. in an asymmetric uplink scenario for UL-only TRP(s) without out-of-synchronization, a "SampleOffset" field can be added to the SRS-Config IE currently defined in 5G NR. The SampleOffset field can specify the time offset in units of samples from the first sample of the start symbol of an actual SRS transmission.

[0347] Each SRS resource can have a separate configuration field, which can contain information about when, where, and how often the SRS will be transmitted. The field information for each SRS resource is as follows:

[0348] - srs-ResourceId field: The srs-ResourceId field can indicate a unique identifier (ID) for the corresponding SRS resource. The srs-ResourceId field can be used to distinguish a specific resource among multiple SRS resources.

[0349] - nrofSRS-Ports field: The nrofSRS-Ports field can define the number of antenna ports used for SRS transmission. More specifically, the nrofSRS-Ports field can set the number of antenna ports to be used in a multi-antenna or MIMO environment. For example, the nrofSRS-Ports field can have values ​​such as 1, 2, and 4, which is an important factor for multi-beamforming.

[0350] - resourceType field: The resourceType field is a field that defines the type of SRS resource, and can be classified as periodic, semi-persistent, and aperiodic. If the resourceType field is set to periodic, it can instruct the UE to transmit the SRS periodically, if the resourceType field is set to semi-persistent, it can instruct the UE to transmit the SRS according to a preset time interval, and if the resourceType field is set to aperiodic, it can instruct the UE to transmit the SRS aperiodicly as needed.

[0351] - transmissionComb field: The transmissionComb field can determine how SRS transmissions are arranged on the frequency. The transmissionComb field can be used in conjunction with combOffset to define how SRS will be transmitted on various frequency resources.

[0352] - cyclicShift field: The cyclicShift field can indicate a cyclic shift value to enable different SRS signals to share frequency resources. The cyclicShift field allows for efficient transmission of multiple SRSs without interference.

[0353] - frequencyPosition field: The frequencyPosition field may be a field that defines the position of the frequency band in which the SRS is transmitted. The frequencyPosition field may be used by the base station to collect channel state information in the desired frequency resources.

[0354] - frequencyShift field: The frequencyShift field can define a shift value in frequency when transmitting SRS. The frequencyShift field can be used to more efficiently place SRS signals in a specific frequency band.

[0355] - frequencyHopping field: The frequencyHopping field can be used to configure whether to use frequency hopping when transmitting SRS. Frequency hopping can be a technique to increase transmission reliability by using various frequency resources.

[0356] - groupOrSequenceHopping field: The groupOrSequenceHopping field can be used to vary the transmission frequency of the SRS using group or sequence hopping. The groupOrSequenceHopping field can be advantageous in reducing interference and securing frequency diversity.

[0357] - resourceMapping field: The resourceMapping field can define the time and frequency resource mapping of the SRS. The resourceMapping field can be composed of detailed parameters such as the symbol start (symbolStart), the number of symbols (numSymbols), and the number of subcarriers (numSubcarriers), and can determine in which symbol and subcarrier the SRS will be transmitted.

[0358] - srs-ConfigIndex field: The srs-ConfigIndex field can be an index that defines the period and transmission time interval of the SRS. Depending on the value of the srs-ConfigIndex field, the SRS can be transmitted periodically or aperiodically.

[0359] - srs-PeriodicityAndOffset field: The srs-PeriodicityAndOffset field can define the interval and start time at which SRS is transmitted periodically. For example, the srs-PeriodicityAndOffset field can instruct SRS to be transmitted at periods such as 20ms, 40ms, or 80ms.

[0360] - srs-TransmissionComb field: The srs-TransmissionComb field can determine how SRS resources are transmitted on the frequency. For example, the srs-TransmissionComb field can configure frequency resources differently through comb0 or comb1.

[0361] - antennaPorts field: The antennaPorts field can define the antenna port number through which the SRS is transmitted. The antennaPorts field is an important field in the multi-antenna configuration for beamforming. When multi-antenna transmission is supported, the SRS can be transmitted through multiple antenna ports, and the NW can measure the channel conditions in various beams through this. Here, the antennaPorts configuration can be different depending on the use of FR 1, FR 2, or FR 2-1. For example, when FR 1 is used, the antennaPorts field value can be set to match the quasi-omni-directional beam pattern (e.g., set one antenna port), and the SampleOffset field configuration can be used to resolve the OOS issue mentioned above. As another example, when FR 2 or FR 2-1 is used, the antennaPorts field value can be set to match the directional beam pattern (e.g., set multiple different antenna Ports), and both the unknown UL-only TRP and the OOS issue mentioned above can be resolved by using the SampleOffset field configuration.

[0362] - srs-PowerControl field: The srs-PowerControl field may be a power control setting used when transmitting SRS. The srs-PowerControl field may be used to adjust the appropriate transmission power to improve the quality of the signal received in the first TRP.

[0363] (2) DCI can trigger an SRS request. To trigger aperiodic SRS transmission, the network can use the SRS request field in the DCI message. The DCI is transmitted to the UE via the PDCCH, and can trigger an SRS request, for example, by using the SRS request field included in any one of DCI format 0_1, DCI format 0_2, or DCI format 1_1. The SRS request field included in any one of DCI format 0_1, DCI format 0_2, or DCI format 1_1 can be composed of 2 bits, and the network can request an SRS from the UE by using the SRS request field included in any one of DCI format 0_1, DCI format 0_2, or DCI format 1_1. The SRS request field value can include whether an SRS transmission is requested or information related to the SRS. More specifically, the SRS request field value can be set as follows.

[0364] For example, a bit value '00' of the SRS request field may mean that no aperiodic SRS resource set is triggered, a bit value '01' of the SRS request field may mean that SRS resource set(s) configured with higher layer parameter aperiodicSRS-ResourceTrigger set to 1, a bit value '10' of the SRS request field may mean that SRS resource set(s) configured with higher layer parameter aperiodicSRS-ResourceTrigger set to 2, and a bit value '11' of the SRS request field may mean that SRS resource set(s) configured with higher layer parameter aperiodicSRS-ResourceTrigger set to 3. set(s) configured with higher layer parameter aperiodicSRS-ResourceTrigger set to 3.

[0365] In the present disclosure, in order to enable a base station (gNB) to estimate the received power and received timing error without out-of-synchronization (OOS) for determining PL offset and TT offset between UL-only TRP(s) and UE in an asymmetric uplink scenario, a "SampleOffset" field can be added to the DCI formats for triggering SRS in the current 5G NR. The SampleOffset field can specify the time offset in units of samples from the first sample of the start symbol of an actual SRS transmission, and the SampleOffset field can be composed of 1 bit or 2 bits.

[0366] If the SampleOffset field consists of 1 bit, a bit value of '0' in the SampleOffset field may mean SRS transmission at the time of uplink transmission with the first TRP (macro TRP), and a bit value of '1' in the SampleOffset field may mean SRS transmission at a time delayed by a TA offset (e.g., SampleOffset) from the time of uplink transmission with the first TRP.

[0367] If the SampleOffset field is composed of 2 bits, a bit value of '00' of the SampleOffset field may mean SRS transmission at the time of uplink transmission with the first TRP, a bit value of '01' of the SampleOffset field may mean SRS transmission at a time delayed by TA offset 1 from the time of uplink transmission with the first TRP, a bit value of '10' of the SampleOffset field may mean SRS transmission at a time delayed (or earlier) by TA offset 2 from the time of uplink transmission with the first TRP, and a bit value of '11' of the SampleOffset field may mean reserved.

[0368] If the SampleOffset field is not added to the RRCReconfiguration and / or RRCConnectionReconfiguration messages mentioned above, the SampleOffset field may be added to the DCI(s) for triggering the SRS transmission exemplified above. On the other hand, if the SampleOffset field is added to the RRCReconfiguration and / or RRCConnectionReconfiguration messages, the SampleOffset field may or may not be added to the DCI(s) for triggering the SRS transmission exemplified above.

[0369] (3) The SRS transmission procedure can proceed as follows:

[0370] The UE may transmit the SRS at a time point delayed (or earlier) by the TA offset from the first sample of the first symbol of the time slot indicated in the DCI message described above. The SRS may be transmitted on allocated frequency resources, which may be configured as the subcarrier range that the UE will use on the uplink. The network may control the transmit power used during the SRS transmission. Power control commands may also be conveyed in the DCI configuration described above.

[0371] (4) SRS reception and UL channel status evaluation can be performed as follows:

[0372] The network can receive the SRS transmitted by the UE and evaluate the uplink channel conditions based on the received SRS. The SRS can be used to evaluate the UL channel conditions in the frequency domain. The network can analyze the received SRS signal to evaluate the channel quality on each subcarrier and reflect this in resource scheduling and beamforming.

[0373] (5) Feedback and resource reallocation can be performed as follows:

[0374] Once the UL channel status is assessed based on the SRS, the network can take the following actions: Based on the SRS received from the UE, the network can optimize UL resource allocation. Furthermore, the network can change the modulation scheme or resource allocation based on the UL channel status. If necessary, the network can instruct the UE to provide additional resource allocation information or change transmission parameters through a new DCI message configuration.

[0375] In the frequency band of FR2 or FR2-1, the UE can form a directional transmission beam pattern. When the UE forms a directional transmission beam pattern, assuming that the form of the UL signal(s) to be transmitted by the UE is SRS, the UE can transmit SRS for PL offset and / or TT offset estimation, PL offset and / or TT offset collection, and / or CSI, uplink beam management, and PL offset and / or TT offset determination through the process of the following embodiment.

[0376] First, the first TRP (e.g., macro TRP) / base station (gNB) / network (NW) may use one or more of RRC, MAC-CE or DCI having SRS request field to instruct the UE to directionally transmit SRS(es) for CSI, uplink beam management, PL offset and / or TT offset determination, PL offset and / or TT offset estimation, PL offset and / or TT offset collection. However, if the UE transmits SRS(es) to UL-only TRP(s) according to the instruction of the network (e.g., macro TRP, gNB or network), the unknown UL-only TRP problem and the OOS problem mentioned above may occur simultaneously.

[0377] In addition, one or more of the information among RRC, MAC-CE for PL offset and / or TT offset estimation, PL offset and / or TT offset collection, PL offset determination indicator, beam-sweeping indicator, transmission point indicator, transmission point (or index), and / or SRS resource configuration(s) may be configured within the above-mentioned CSI, uplink beam management, PL offset and / or TT offset determination.

[0378] For example, the RRC and / or MAC-CE may be configured to include one or more of the following fields: PL offset determination indicator and / or beam sweeping indicator and / or transmission timing offset value(s) (indices) and / or SRS resource configuration(s) and / or Joint / UL TCI state(s).

[0379] The PL Offset Determination Indicator field may consist of 1 bit. If the bit information of the PL Offset Determination Indicator field is '1', it may mean that this RRC and / or MAC-CE is for the network (e.g., the first TRP (e.g., macro TRP), base station (gNB), or network) to determine the PL offset value(s) for UL-only TRP(s), and the PL Offset Determination Indicator field may be omitted since the beam sweeping indicator field that follows may take over this role.

[0380] The beam sweeping indicator field may be configured with, for example, 1 bit to enable RRC and / or MAC-CE to determine PL offset and to resolve unknown UL-only TRP issues. If the bit information of the beam sweeping indicator field is '1', it may mean that the UE is instructed to transmit SRSs by performing beam sweeping. On the other hand, if the bit information of the beam sweeping indicator field is '0', it may mean that the SRS(es) are instructed to be transmitted without beam sweeping.

[0381] In the transmission timing value(s) (or transmission timing indexes) field, the transmission timing offset value(s) and the index(es) indicating the same may mean offset value(s) (or offset indices) with respect to the transmission timing toward the first TRP configured by the UE during the connection process with the first TRP (e.g., macro TRP). For example, if the transmission timing offset value is 0, it may mean the transmission timing value toward the first TRP (e.g., macro TRP), and if the transmission timing offset value is a positive value, a positive transmission timing offset value may mean that the SRS(s) are transmitted by the positive offset value earlier (or earlier) than the transmission timing toward the first TRP, and if the transmission timing offset value is a negative value, a negative transmission timing offset value may mean that the SRS(s) are transmitted by delaying the transmission timing toward the first TRP by the negative offset value.

[0382] The SRS resource configuration(s) field may indicate configuration for generating SRS resources and / or SRS sequences to be transmitted in UL-only TRP(s).

[0383] For example, the SRS resource configuration(s) may mean determining a PL offset from the PL offset determination indicator field information, but instructing not to perform beam sweeping, and when the transmission point offset value is 0, the configuration for generating the SRS sequence to be applied and the SRS time / frequency resource information(s) may mean.

[0384] As another example, the SRS resource configuration(s) may mean determining a PL offset from the PL offset determination indicator field information, performing beam sweeping, and generating a beam-swept SRS sequence for each applicable transmission point offset value when different transmission point offset values ​​are determined, and SRS time / frequency resource information(s).

[0385] As another example, the SRS resource configuration(s) may not determine the PL offset from the PL offset determination indicator field information, but may mean a configuration for generating an SRS sequence that is beam-swept for each transmission point in time when the transmission point offset value is 0 without beam sweeping, and SRS time / frequency resource information(s).

[0386] The Joint / UL TCI state(s) field may indicate the UE's transmit beam direction for the SRS(s) to be transmitted.

[0387] For example, the combined / UL TCI state(s) field may determine the PL offset from the above field information, but may indicate not to perform beam sweeping, and if the transmit point offset value is 0, may mean the UL transmit beam direction(s) to transmit the SRS(s) configured from the above field information.

[0388] As another example, the combined / UL TCI state(s) field may not determine the PL offset from the above field information, and may indicate the UL transmission beam direction(s) to transmit the SRS(s) configured from the above field information when beam sweeping is not performed and the transmission point offset value is 0.

[0389] Meanwhile, in a situation where the UE can form a transmission beam pattern to have quasi-omnidirectionality in the FR1 frequency band, assuming that the form of the UL signal(s) to be transmitted is a PRACH preamble, the UE can transmit a preamble for determining the TA / PL offset, TT offset, estimating the TT offset, and collecting the TT offset through the procedure described below.

[0390] First, the network (e.g., the first TRP (e.g., macro TRP), the base station, or the network) can instruct the UE to transmit a predefined preamble quasi-omnidirectionally for determining TA / PL offset, TT offset, TT offset estimation, and TT offset collection using one or more of RRC, MAC-CE, or DCI for PDCCH-order. This case can solve both the unknown UL-only TRP problem and the OOS problem mentioned above.

[0391] One or more field settings of RRC, MAC-CE or DCI message for TA / PL offset, TT offset determination, TT offset estimation and TT offset collection can be configured as follows.

[0392] (1) The RRC and / or MAC-CE message may include message fields such as a PL offset determination indicator, a random access preamble index, and a random access order (RO).

[0393] For example, the PL Offset Determination Indicator field may consist of 1 bit. If the bit information of the PL Offset Determination Indicator field is '1', it may mean that the RRC and / or MAC-CE message is for the network to determine the PL offset value(s) for the UL-only TRP(s). The Random Access Preamble Index field may indicate the index of a preamble to be transmitted to the UL-only TRP(s) so as to have quasi-omni directional, and the RO field may mean time / frequency resource location information at which the preamble is to be transmitted. The time / frequency resource of the RO may be determined by the network as the time / frequency resource for one RO, or may be all time / frequency resource locations of the RO case defined in the current 5G NR standard (in this case, the UE may ignore SSB). If all time / frequency resources of the RO case defined in the current 5G NR standard are indicated, the UE may transmit a preamble by randomly selecting one time / frequency resource location among all time / frequency resources of the RO case defined in the current 5G NR standard.

[0394] (2) In the case of DCI for PDCCH-order, the DCI 1_0 format for PDCCH-order may be configured with message fields such as a PL offset determination indicator in addition to the existing fields. Here, the PL offset determination indicator field (or asymmetry indicator field) may be configured with 1 bit. If the bit information of the PL offset determination indicator field is '1', it may mean that this DCI is for the network to determine the PL offset value(s) for UL-only TRP(s). If the bit information of the PL offset determination indicator field is '0', it may follow the DCI for PDCCH order in the current 5G NR standard. Here, it may be configured not to add the PL offset determination indicator field. In other words, since the UE transmits the preamble according to the indication of the received DCI for PDCCH-order even if the UE does not know whether the DCI is for PL offset determination, there may be no problem in the operation of the network determining the PL offset value(s) using the preamble transmitted from the UE.

[0395] In addition, since the UL / supplementary uplink (SUL) indicator and / or SS / PBCH index of the current 5G NR standard are useless when the bit value of the Asym indicator field is '1', the UL / SUL indicator and / or SS / PBCH fields can be reused for transmission with a UL-only TRP. As an example of reuse, PL offset index (and / or transmit power value / index) information for determining the transmit power of the preamble transmission by DCI can be set in these UL / SUL indicator and / or SS / PBCH index fields.

[0396] Meanwhile, in a situation where the UE can form a transmission beam pattern to have a directional orientation in the FR2 frequency band or the FR2-1 frequency band, assuming that the form of the UL signal(s) to be transmitted by the UE is a preamble, the UE can transmit a preamble for determining the TA / PL offset, TT offset, estimating the TT offset, and collecting the TT offset through the following procedure.

[0397] First, the network (e.g., the first TRP (e.g., macro TRP), the base station (gNB), or the network) can instruct the UE to transmit the preamble(s) directionally for RRC, MAC-CE, or DCI for PDCCH-order, determination of the / PL offset, TT offset estimation, and collection of the TT offset. However, if the UE transmits the preamble(s) to UL-only TRP(s) as instructed by the network, the OOS problem mentioned above can be solved, but the unknown UL-only TRP problem may occur.

[0398] One or more of the DCI messages for RRC, MAC-CE or PDCCH-order for determining TA / PL offset, TT offset, TT offset estimation and TT offset collection may have the following fields:

[0399] (1) For RRC and / or MAC-CE, it consists of message fields such as PL offset determination indicator and / or beam sweeping indicator and / or random access preamble index and / or PRACH preamble resource setting(s).

[0400] The PL Offset Determination Indicator field may consist of 1 bit. If the bit information of the PL Offset Determination Indicator field is '1', it may mean that the RRC and / or MAC-CE are for the network to determine the PL offset value(s) for the UL-only TRP(s), and the PL Offset Determination Indicator field may be omitted since the beam sweeping indicator field that follows may replace the role of the PL Offset Determination Indicator field.

[0401] The Beam Sweeping Indicator field may consist of, for example, 1 bit to enable RRC and / or MAC-CE to determine PL offset and to address unknown UL-only TRP issues. If the bit information of the Beam Sweeping Indicator field is '1', it may mean that the UE is instructed to transmit preambles by beam sweeping. If the bit information of the Beam Sweeping Indicator field is '0', it may mean that the UE is instructed to transmit preamble(s) without beam sweeping.

[0402] The random access preamble index field may indicate the index of the preamble to be generated and transmitted.

[0403] The PRACH preamble resource configuration(s) field may indicate time / frequency resource location information on which a preamble will be carried and transmitted. The time / frequency resources of the preamble resource configuration(s) may indicate the configuration of all time / frequency resources to be beam-swept, if beam sweeping is indicated based on information in any one of the fields described above (e.g., the beam sweeping indicator field). On the other hand, if beam sweeping is not indicated based on information in any one of the fields described above (e.g., the beam sweeping indicator field), it may indicate the configuration of one or more non-beam-swept time / frequency resources.

[0404] (2) In the case of DCI for PDCCH-order, the DCI 1_0 format for PDCCH-order may be configured to include fields such as a PL offset determination indicator (or an asymmetric indicator) and / or a beam sweeping indicator in addition to the existing fields.

[0405] The PL Offset Determination Indicator field may consist of 1 bit. If the bit information of the PL Offset Determination Indicator field is '1', it may mean that the corresponding DCI is for the network to determine the PL offset value(s) for UL-only TRP(s). In this case, the PL Offset Determination Indicator field may be omitted because the beam sweeping indicator field that follows can take over this role. In addition, if the PL Offset Determination Indicator field is additionally configured and the bit value of the PL Offset Determination Indicator field is '1', the UL / SUL indicator, SS / PBCH index, or PRACH mask index are useless in the current 5G NR standard, so the fields can be reused for UL-only TRP transmission.

[0406] For example, the UL / SUL indicator can be reused as a beam sweeping indicator as described below. More specifically, if the bit information of the UL / SUL indicator is '1', it may mean that the UE is instructed to perform beam sweeping, and if the bit information of the UL / SUL indicator is '0', it may mean that the UE is instructed not to perform beam sweeping.

[0407] Additionally, the SS / PBCH index and the PRACH mask index can be reused as time / frequency resource(s) and / or transmission power allocation fields for the beam direction(s) of the preamble(s) based on whether beam sweeping is performed. For example, if the bit value of the PL offset determination indicator is '1' and the bit value of the UL / SUL indicator is '1', the bits of the SS / PBCH index and the PRACH mask index can be used to allocate time / frequency resources and / or transmission power for the preambles to be transmitted in a beam sweeping manner to the UE, and all possible allocation methods can be included in the scope of the present invention. As a more specific allocation example, the 4 bits of the PRACH mask index may be used to indicate the location of one time / frequency resource of a preamble to be beam swept within a frame, the 4 bits of the SS / PBCH index may be used to indicate the location of another time / frequency resource of a preamble to be beam swept within a frame, and the remaining 2 bits may be used to indicate an offset value from the Tx power configured by the UE during the connection process with the first TRP.

[0408] As another allocation example, 4 bits of the PRACH mask index can be used to indicate the position of one time / frequency resource of a preamble to be beam swept within the frame, 4 bits out of 6 bits of the SS / PBCH index can be used to indicate the positions of another multiple time / frequency resources of the preamble to be beam swept within the frame, and the remaining 2 bits can be used to indicate an offset value from the Tx power configured by the UE during the connection process with the first TRP. Here, when up to 1 bit of the UL / SUL indicator is additionally used for the allocation of preambles to be beam swept, it can be used for the allocation of time / frequency resource(s) of the beam direction(s) of the preamble(s) and / or the transmission power of the preamble(s) to be transmitted.

[0409] The beam sweeping indicator field may be configured with, for example, 1 bit for the DCI for PDCCH-order to determine PL offset and to resolve the unknown UL-only TRP issue. If the bit information of the beam sweeping indicator field is '1', it may mean that the UE is instructed to transmit preambles by beam sweeping, and if the bit information of the beam sweeping indicator field is '0', it may mean that the preamble(s) are to be transmitted without beam sweeping.

[0410] In a situation where the UE can form a transmit beam pattern such that it has quasi-omni directional capability in the FR1 frequency band and / or directional capability in the FR2 frequency band and the FR2-1 frequency band, assuming that the form of the UL signal(s) to be transmitted by the UE is a preamble, the UE can transmit a preamble for determining TA / PL offset, TT offset, estimating TT offset, and collecting TT offset through the procedure described below.

[0411] First, the network (e.g., the first TRP (e.g., macro TRP), the base station (gNB) or the network (NW)) can instruct the UE to transmit the preamble semi-omnidirectionally or directionally using one or more of RRC, MAC-CE or DCI for PDCCH-order for determining TA / PL offset, TT offset, estimating TT offset and collecting TT offset. In this case, the network can instruct the UE to transmit one preamble with resource configuration over the indicated time and frequency resources. In this case, the OOS problem mentioned above can be solved, but the unknown UL-only TRP problem cannot be solved. In addition, to solve the unknown UL-only TRP problem, multiple preambles beam-swept in different directions can be transmitted.

[0412] The field configuration of the DCI message for RRC, MAC-CE or PDCCH-order for determining TA / PL offset, TT offset, estimating TT offset and collecting TT offset can be configured as follows.

[0413] (1) RRC and / or MAC-CE may include message fields such as PL offset determination indicator, beam sweeping indicator, random access preamble index, or PRACH preamble resource configuration(s).

[0414] The PL Offset Determination Indicator field may consist of 1 bit. If the bit information of the PL Offset Determination Indicator field is '1', it may mean that the RRC and / or MAC-CE are for the network to determine the PL offset value(s) for the UL-only TRP(s), and the PL Offset Determination Indicator field may be replaced by the Beam Sweeping Indicator field that follows it. Therefore, when the Beam Sweeping Indicator field is used, the PL Offset Determination Indicator field may be omitted.

[0415] The Beam Sweeping Indicator field may be configured with, for example, 1 bit to allow RRC and / or MAC-CE to determine PL offset and to address unknown UL-only TRP issues. If the bit information of the Beam Sweeping Indicator field is '1', it may mean that the UE is instructed to transmit preambles by beam sweeping. On the other hand, if the bit information of the Beam Sweeping Indicator field is '0', it may mean that the UE is instructed to transmit preamble(s) without beam sweeping.

[0416] The random access preamble index field may indicate the index of the preamble to be generated and transmitted.

[0417] The PRACH preamble resource configuration(s) field may indicate time / frequency resource location information on which the preamble will be carried and transmitted. The time / frequency resources of the preamble resource configuration(s) may indicate the configuration of all time / frequency resources to be beam-swept when beam sweeping is to be performed based on the field information described above (e.g., beam sweeping indicator field). On the other hand, when beam sweeping is not to be performed based on the field information described above, it may indicate the configuration of one or more non-beam-swept time / frequency resources.

[0418] (2) In the case of DCI for PDCCH-order, the DCI 1_0 format for the purpose may additionally include fields such as a PL offset determination indicator (or an asymmetric indicator) and / or a beam sweeping indicator, along with the existing fields.

[0419] The PL Offset Determination Indicator field may consist of 1 bit, and if the bit information of the PL Offset Determination Indicator field is '1', it may mean that the DCI is for the network to determine the PL offset value(s) for the UL-only TRP(s). In this case, since the PL Offset Determination Indicator field can be replaced by the Beam Sweeping Indicator field that follows, the PL Offset Determination Indicator field may be omitted when the Beam Sweeping Indicator field is used.

[0420] In addition, if an Asym indicator field is additionally configured and the bit value of the Asym indicator field is '1', the UL / SUL indicator and / or SS / PBCH index and / or PRACH mask index defined in the current 5G NR standard may become meaningless. Therefore, the UL / SUL indicator and / or SS / PBCH index and / or PRACH mask index defined in the current 5G NR standard can be reused for UL-only TRP transmission. For example, the UL / SUL indicator can be reused as a beam sweeping indicator to be described below. In other words, if the bit information of the UL / SUL indicator is '1', the UE can determine that it is instructed to perform beam sweeping, and if the bit information of the UL / SUL indicator is '0', the UE can determine that it is instructed not to perform beam sweeping.

[0421] In addition, the SS / PBCH index and the PRACH mask index can be reused as time / frequency resource(s) of the beam direction(s) of the preamble(s) depending on whether beam sweeping is performed and / or as transmission power allocation fields of the preamble(s) to be transmitted. For example, if the bit value of the Asym indicator from the information described above is '1' and the bit value of the UL / SUL indicator is '1', the bits of the SS / PBCH index and the PRACH mask index can be used to allocate time / frequency resources and / or transmission power when the preambles are transmitted by beam sweeping. This is just one example, and all possible allocation methods can be included in the scope of the present invention.

[0422] As an example of an allocation according to the above example, 4 bits of the PRACH mask index can be used to indicate the location of one time / frequency resource of the preamble to be beam swept within the frame, 4 bits out of 6 bits of the SS / PBCH index can be used to indicate the location of another time / frequency resource of the preamble to be beam swept within the frame, and the remaining 2 bits can be used to indicate an offset value with respect to the transmission power configured by the UE during the connection process with the first TRP (e.g., macro TRP).

[0423] As another allocation example of the above example, 4 bits of the PRACH mask index can be used to indicate the position of one time / frequency resource of the preamble to be beam swept within the frame, for example 4 bits out of 6 bits of the SS / PBCH index can be used to indicate the positions of another multiple time / frequency resources of the preamble to be beam swept within the frame, and the remaining 2 bits can be used to indicate an offset value from the transmit power configured by the UE during the connection process with the first TRP (e.g., macro TRP). Here, when up to 1 bit of the UL / SUL indicator is additionally used for the allocation of preambles to be beam swept, it can be used for allocating the time / frequency resource(s) of the beam direction(s) of the preamble(s) and / or the transmit power of the preamble(s) to be transmitted.

[0424] The beam sweeping indicator field may be configured with, for example, 1 bit for the DCI for PDCCH-order to determine PL offset and to address the unknown UL-only TRP issue. If the bit information of the beam sweeping indicator field is '1', the UE may determine that it is instructed to transmit preambles by beam sweeping, and if the bit information of the beam sweeping indicator field is '0', the UE may determine that it is instructed to transmit preamble(s) without beam sweeping.

[0425] Other embodiments based on the above are described below.

[0426] After completing the initial system connection setup with the first TRP, which is a macro TRP, and establishing a link connection, the UE may use the SRS or preamble to enable the base station (gNB) to determine the PL offset of the uplink-only TRP. Whether the SRS or the preamble is used to determine the PL offset may be the same or different depending on whether the UE establishes a connection in the FR1 frequency band or the FR2 frequency band.

[0427] For FR1, when considering the use of a preamble based on the PDCCH-order DCI mechanism for PL offset determination, the UE can avoid unknown uplink TRPs due to the omnidirectional beam pattern in the FR1 frequency band. Furthermore, since the preamble inherently uses a long CP, it can also prevent UL out-of-sync (OOS). Another advantage of using a preamble is that only a single preamble needs to be transmitted. However, interference may occur with cells managed by another macro TRP, the first TRP, so the omnidirectional beam pattern may require different transmission power adjustments when transmitting the preamble in an asymmetric scenario compared to the existing PDCCH-order DCI. In addition, for the PDCCH-order DCI-based contention-free random access (CFRA) preamble transmission based on the current 5G NR standard, the UE must monitor for a response to the transmitted preamble, since the first TRP may indicate the TRP that receives the preamble.

[0428] However, in an asymmetric scenario, the first TRP, which is a macro TRP, cannot indicate a single TRP for the PRACH mask index (i.e., time slot / frequency resource group) of the preamble to be transmitted by the UE. Therefore, the first TRP, which is a macro TRP, must inform each of the possible uplink-only TRPs of the corresponding PRACH mask index information, and then monitor the preamble transmitted by the UE. The delay caused by this procedure may cause the RAR monitoring time to exceed after the UE transmits the preamble. Therefore, a new field needs to be used in the DCI to disable RAR monitoring for the UE. In addition, the bit index of the new field in the DCI can notify the UE about the asymmetric scenario, and fields such as SS / PBCH index, UL / SUL index, and PRACH association indicator can be reused to configure other information.

[0429] Alternatively, UL OOS is a problem when using SRS for PL offset determination in the FR1 frequency band, but this can be solved by reusing aperiodic SRS configurations and transmissions without beam switching mode used in existing UL beam management. Here, the transmission timing of each set of SRS configurations is determined by the TA offset (Δ ) described in Fig. 9. TA )(for example, 0 or T cp / 2) can be used for UL beam management in connected state, except for adjusting at sample level.

[0430] For the FR2 frequency band, considering the use of a preamble based on the PDCCH-order DCI mechanism for PL offset determination may help resolve UL OOS due to its long CP. However, to address the issue of unknown uplink-only TRPs, the UE must transmit multiple beam-swept preambles, which may result in a significant performance impact on the preamble transmission procedure. Furthermore, using beam-swept preambles for PL offset determination has the disadvantage that the preambles may not be detected in advance, depending on the received beam pattern of the uplink-only TRP.

[0431] Alternatively, using SRS for PL offset determination in the FR2 frequency band may result in unknown uplink-only TRP and UL OOS issues, which can be addressed by reusing the periodic / semi-permanent SRS configurations and transmissions used in existing UL beam management. Here, the transmission timing of each set of SRS configurations is determined by the TA offset (Δ ) described in FIG. 9. TA )(for example, 0 or T cp / 2) can be used for UL beam management in connected state, except for adjusting at sample level.

[0432] Therefore, when determining the PL offset in the FR1 frequency band, Proposal 1 below can be used, considering that all problems can be solved.

[0433] [Proposal 1]

[0434] > For PDCCH-order DCI-based PL offset determination in the FR1 frequency band, a new bit DCI field can be introduced in DCI format 1_0.

[0435] > The new DCI field may be present if the corresponding RRC parameter is enabled and there is no TCI state with a PL offset set.

[0436] > Bit field index 0 of the new DCI field may indicate that PL offset determination is not performed in PRACH transmission and response monitoring for PRACH transmission is performed.

[0437] > Bit field index 1 of the new DCI field may indicate that the PL offset is determined in the PRACH transmission and that there is no response monitoring for the PRACH transmission.

[0438] > Depending on the bit field index 1 of the new DCI field, the field to be reused can display different information as described above.

[0439] When determining the PL offset in the FR2 frequency band, Suggestion 2 below can be used to minimize the specification impact.

[0440] [Proposal 2]

[0441] To determine SRS-based PL offset in the FR2 frequency band, a new field can be added to the SRS configuration according to the current 5G RN standard.

[0442] > A new field related to transmission timing advance can be specified in the RRC / SRS trigger MAC-CE format for periodic / semi-persistent SRS transmission in multi-beam directional beamforming mode based on the current 5G RN standard specifications.

[0443] Considering a common solution for PL offset determination in both FR1 and FR2 frequency bands, Proposal 3 below can be used.

[0444] [Proposal 3]

[0445] To determine PL offset based on SRS, a new field can be added to the SRS configuration according to the current 5G NR specification.

[0446] > For the FR2 frequency band, a new field related to transmission timing advance can be specified in the RRC / SRS trigger MAC-CE format for periodic / semi-persistent SRS transmission in multi-beam directional beamforming mode according to the current 5G NR specification.

[0447] > For the FR1 frequency band, a new field related to transmission timing advance can be specified in the DCI (e.g., DCI formats 0_1, 0_2, 1_1) for aperiodic SRS transmission in the existing omnidirectional beamforming mode.

[0448] The new 1-bit field configured in DCI Format 1_0 for the unified TCI of 3GPP Rel-17 and the unified TCI of 3GPP Rel-18 is specified differently. A single specification supporting both unified TCIs would be an optimal solution. From this perspective, a single specification approach for the unified TCI of Rel-17 / Rel-18 is proposed as follows.

[0449] (1) A new 1-bit DCI field may be configured in DCI format 1_0 to indicate a PL offset for a PDCCH-order PRACH. The new 1-bit DCI field is assumed to be present if the corresponding RRC parameter configuring the presence of the DCI field is enabled and at least one TCI state is configured with a PL offset.

[0450] (2) When a joint / UL TCI state is indicated in the Rel-17 Unified TCI, a new 1-bit field index 0 in DCI format 1_0 may indicate that there is no PL offset associated with the indicated TCI state. A bit field index 1 of the new field may indicate that the PL offset associated with the indicated TCI state is included in the PRACH transmit power calculation. For the bit field index 1 of the new field, other unnecessary fields such as SS / PBCH index and / or UL / SUL indicator may be reused to indicate other information (e.g., information related to transmit power adjustment, repetition count of the corresponding PRACH preamble, indicated TCI state, or whether monitoring is not performed for the corresponding PRACH preamble).

[0451] (3) When two joint / UL TCI states are indicated in the Rel-18 Unified TCI, bit field index 0 of the newly defined field in the DCI may indicate that there is no PL offset associated with the indicated TCI states, similar to the case of one indicated joint / UL TCI state. Bit field index 1 of the new field may indicate that the PL offset associated with one of the two indicated TCI states is included in the PRACH transmit power calculation. Unnecessary fields such as SS / PBCH index, UL / SUL indicator, and PRACH association indicator may be reused for bit field index 1 of the new field to indicate other information (e.g., a 1-bit indicator for one of the two indicated TCI states, information related to transmit power adjustment, the repetition count of the corresponding PRACH preamble, the indicated TCI state, or whether monitoring is not performed for the corresponding PRACH preamble, etc.). Note that if simultaneous UL data transmission is required, other information may indicate whether simultaneous transmission is performed via the PL offset associated with these two TCI states.

[0452] [Proposal 4]

[0453] A new 1-bit DCI field can be introduced in DCI format 1_0 to indicate the PL offset for PDCCH-order PRACH.

[0454] (1) A new 1-bit in the DCI field may be present if the corresponding RRC parameter (a new RRC configuring the presence of a 1-bit DCI field) is enabled and at least one TCI state is configured with a PL offset.

[0455] (2) Field index 0 of a new 1-bit field in the DCI field may indicate that there is no PL offset associated with the indicated TCI states and that response monitoring for PRACH transmission is performed.

[0456] (3) Field index 1 of a new 1-bit field in the DCI field may indicate that the PL offset associated with the indicated TCI states is included in the PRACH transmit power calculation and that response monitoring for the corresponding PRACH transmission is not performed.

[0457] (4) When one joint / UL TCI state is indicated in the Rel-17 Unified TCI, the SS / PBCH index and / or UL / SUL indicator can be reused for field index 1 of the new 1-bit field of the DCI field to indicate other information.

[0458] (5) When two joint / UL TCI states are indicated in the Rel-18 Unified TCI, the SS / PBCH index, UL / SUL index and / or PRACH association index may be reused for field index 1 of the new 1-bit field of the DCI field to indicate other information.

[0459] For the FR1 frequency band, considering that a preamble based on the PDCCH-order DCI mechanism is used to determine the PL offset, the UE can avoid unknown UL-only TRPs (UTs) caused by the omnidirectional beam patterns in the FR1 frequency band. Furthermore, since the preamble inherently uses a long CP, it can help prevent UL out-of-synchronization (OOS). Another advantage of using a preamble is that only a single preamble transmission is required. The network (NW) can determine the PL offset by requesting all UTs managed by the first TRP, which is a macro TRP, to listen for a PDCCH-order DCI-based preamble transmission within the time slot / frequency resource group configured by the PRACH mask index of the corresponding DCI.

[0460] For the FR2 frequency band, considering that a preamble based on the PDCCH-order DCI mechanism is used to determine the PL offset, the UE transmits the preamble using a long CP, which can help address the UL OOS issue. However, addressing the unknown UT issue requires transmitting multiple beam-swept preambles, which could lead to significant specification changes to the preamble transmission procedure.

[0461] On the other hand, using SRS to determine PL offset in the FR2 frequency band can lead to both unknown UT and UL OOS issues. However, these issues can be addressed by reusing the periodic / semi-persistent SRS configuration and transmission (based on beam switching mode) used in the current UL beam management of the 5G NR specification and adjusting the Tx timing of each SRS configuration set.

[0462] In summary, if either the SRS or the preamble is used in both the FR1 and FR2 frequency bands, the PL offset can be determined using the preamble. Otherwise, the PL offset can be determined using the preamble in the FR1 frequency band and the SRS in the FR2 frequency band. Proposal 4a for determining the PL offset using the preamble in the FR1 frequency band and the SRS in the FR2 frequency band is as follows.

[0463] [Proposal 4a]

[0464] To indicate the PL offset of PDCCH-order PRACH in FR1 frequency band, when two joint / UL TCI states are indicated in the integrated TCI in 3GPP Rel-18 specification:

[0465] > The DCI field may be present when the corresponding RRC parameter (a new RRC that configures the presence of a 1-bit DCI field) is enabled and there is no TCI state with a configured PL offset.

[0466] >> Bit index 0 in the DCI field may indicate that PL offset determination is performed.

[0467] >> Bit index 1 in the DCI field may indicate that PL offset determination is performed.

[0468] >> For further study (FFS): Whether bit index 0 or 1 in the DCI field indicates PL RS and / or UL power control parameters for PRACH transmission.

[0469] > The DCI field may be present if the corresponding RRC parameter is enabled and one or more TCI states are configured with a PL offset.

[0470] >> Bit index 0 in the DCI field may indicate that the PL offset associated with the first indicated joint / UL TCI state is included in the PRACH transmit power calculation.

[0471] >> Bit index 1 in the DCI field may indicate that the PL offset associated with the second indicated joint / UL TCI state is included in the PRACH transmit power calculation.

[0472] >> Research on how to indicate the following information in DCI format 1_0 via a new 1-bit DCI field:

[0473] >>> PL RS for PRACH transmission

[0474] >>> Other power control parameters for PRACH transmission

[0475] >>> Transmit beam for PRACH transmission

[0476] [Proposal 4b]

[0477] When two joint / UL TCI states are indicated in the integrated TCI in 3GPP Rel-18 specification to indicate the PL offset of PDCCH-order PRACH after performing PL offset determination in FR2 frequency band:

[0478] > The DCI field may be present if the corresponding RRC parameter (a new RRC that configures the presence of a 1-bit DCI field) is enabled and one or more TCI states are configured with a PL offset.

[0479] >> Bit index 0 in the DCI field may indicate that the PL offset associated with the first indicated joint / UL TCI state is included in the PRACH transmit power calculation.

[0480] >> Bit index 1 in the DCI field may indicate that the PL offset associated with the second indicated joint / UL TCI state is included in the PRACH transmit power calculation.

[0481] >> Research on how to indicate the following information in DCI format 1_0 via a new 1-bit DCI field:

[0482] >>> PL RS for PRACH transmission

[0483] >>> Other power control parameters for PRACH transmission

[0484] >>> Tx beam for PRACH transmission

[0485] If beam sweeping is performed using the preamble as a UL signal to calculate the PL offset, the UE transmits the preamble by beam sweeping the network-specified preamble in a predefined set of directions, which has the effect of reducing latency.

[0486] An advantage of using the preamble for beam sweeping is that, compared to SRS(s), the PRACH preamble conceptually has a much longer CP. Therefore, even if the OOS problem described above occurs in the uplink, reverse synchronization and / or reverse received power (related to the PL offset described below) can be successfully estimated in UL-only TRPs.

[0487] When the UE beam sweeps the preamble, the first TRP, which is a macro TRP, can transmit the preamble(s) predetermined together with the RO information to the UE. Therefore, the UE, which has received the preamble predetermined together with the RO information, can transmit the preamble(s) provided by the first TRP with the transmit power calculated as described above, or with the (initial) transmit power received from the first TRP as is, or with a modified transmit power. At this time, the UE can transmit the preamble by beam sweeping in a set of predefined directions at the transmission time of the UL synchronization obtained through the RRC reconfiguration complete (RRC reconfiguration complete - step S1023 of FIG. 10a) between the first TRP and the UE.

[0488] When using preamble(s) for beam sweeping, UL-only TRPs that receive different preambles from multiple UEs simultaneously or in a partially overlapping state can successfully distinguish between them and estimate reverse synchronization.

[0489] When a first TRP, which is a macro TRP, instructs the UE to perform beam sweeping using PRACH preamble(s), the method of transmitting the instruction information may be such that the first TRP transmits a separate MAC-CE including a physical cell identifier (PCI) field, a random access preamble index field, an RO configuration / indexes field, and a sweeping / repetition number field to the UE. Here, the PCI field may mean PCI information, the random access preamble index field may mean network-specified preamble information, the RO configuration / indexes field may mean RO configuration and / or RO indexes, which are location information of time resources and frequency resources for transmitting a preamble generated from the random access preamble index field, and the sweeping / repetition number field may mean the number of preambles to be swept and / or repeated.

[0490] The RO setting above does not refer to a single RO, but rather a grouping setting list when multiple ROs are grouped. The ROs in the setting list may refer to those used for sweeping / repeating the preamble. Additionally, the RO indexes may refer to the indexes of multiple ROs used for sweeping / repeating.

[0491] Among the configurations of the separate MAC-CE described above, the PCI field may not be included in the separate MAC-CE.

[0492] When the first TRP, which is a macro TRP, instructs the UE to perform beam sweeping using the PRACH preamble(s), another method of transmitting the instruction information may be via RRC signaling to instruct the UE to perform beam sweeping using the PRACH preamble(s). The RRC signaling may include information such as a PCI field, a random access preamble index field, a RO configuration / indexes field, and a sweeping / repetition count field, similar to MAC-CE. Additionally, as described above, the PCI field may not be included, similar to MAC-CE.

[0493] If beam-sweeping SRS is used as an UL signal, the UE can transmit SRS by beam-sweeping in a set of predefined directions at different transmission times to resolve uplink asynchronization. Therefore, compared to beam-sweeping the preamble, beam-sweeping SRS may result in longer latency. Here, the following problems may arise when beam-sweeping SRS.

[0494] First, from the perspective of a UE whose reference timing is already aligned between the first TRP and the UE, when using an SRS with a CP of a standard length, the surrounding UL-only TRPs close to the UE may be in an OOS state with the UE. Therefore, the UL-only TRPs have difficulty decoding signals received from the UE.

[0495] Second, to prepare for cases where the UE is in an OOS state with the surrounding UL-only TRPs near the UE, UL-only TRPs can utilize energy estimation. However, if the energy estimation method is used to detect the SRS transmitted by the UE, UL-only TRPs face the problem of having difficulty identifying the UE transmitting the SRS.

[0496] Third, when a UL-only TRP receives SRSs from multiple UEs simultaneously, the SRSs are measured at mixed energy levels due to the multiple SRSs, making it impossible to identify the UEs that transmitted the SRSs.

[0497] Fourth, the first TRP can schedule SRS transmission sequentially for each UE to prevent multiple UEs from transmitting SRS simultaneously. However, if there is an SRS transmitted by a second UE that transmits SRS under the control of another macro TRP (or head TRP), the UL-only TRP cannot distinguish between the UE transmitting SRS under the control of the first TRP and the second UE transmitting SRS under the control of another macro TRP.

[0498] Fifth, the method of sequentially transmitting SRSs by multiple UEs under the control of the first TRP is highly inefficient in terms of resource efficiency. Furthermore, the procedure for searching for UL-only TRPs by beam sweeping using SRS as an UL signal, obtaining a TA between the UE and the UL-only TRP, problems encountered when searching for UL-only TRPs using SRS used in beam management (BM), and a method for searching for UL-only TRPs are described below.

[0499] <Problems with UL-only TRP search using existing SRS>

[0500] The UL-only TRP that contributes the most to the transmission of UL traffic of the UE is the TRP close to the UE, but the TRP close to (adjacent to) the UE is more likely to be in an OOS state than the first TRP (or macro TRP or head TRP).

[0501] The current TRP search method or beam search method using SRS according to the 5G NR standard has the advantage of being less impacted by changes to the 5G NR standard because it can transmit multiple SRSs by reusing SRS configurations through RRC. However, because of the short CP, it cannot handle the OOS problem during SRS transmission, making it difficult to estimate the SRS for UL-only TRPs located nearby.

[0502] <Method for finding UL-only TRPs using existing SRS>

[0503] When comparing the first distance between the UE and the first TRP, which is a macro TRP, and the second distance, which is the distance between the UE and the UL-only TRP, the second distance is much shorter than the first distance. In other words, it can be assumed that the distance between the UE and the UL-only TRP is closer than the distance between the UE and the first TRP. This is because if the second distance has a longer distance value than the first distance, there is no advantage for the UE to transmit UL data to the UL-only TRP.

[0504] In particular, since a TRP useful as a UL-only TRP has better UL transmission efficiency the closer it is to the UE, the macro TRP needs to gradually search for a UL-only TRP suitable for the UE. In other words, the macro TRP can search for a UL-only TRP within a certain distance from the UE in the first search. If the UE cannot find a UL-only TRP for UL transmission in the first search, the macro TRP can perform a second search at a distance slightly greater than the first search distance. In other words, the macro TRP can search for a UL-only TRP located within the distance for the second search from the UE.

[0505] For UL-only TRP search within a distance of 1 step, the first TRP, which is a macro TRP, may set a TA value equal to 1 / 3 of the TA value between the first TRP and the UE as the TA value for UL-only TRP search. In addition, for UL-only TRP search within a distance of 1 step, the first TRP may set a TA value equal to 2 / 3 of the TA value between the first TRP and the UE as the TA value for UL-only TRP search. In addition, for UL-only TRP search within a distance of 3 steps, the first TRP may set a TA value equal to the TA value between the first TRP and the UE as the TA value for UL-only TRP search. Here, the values ​​1 / 3 and 2 / 3 are merely examples and may be set to other values ​​that are equal to or less than 1. The TA values ​​for the 1-step search, the 2-step search, and the 3-step search are referred to as 'TA1', 'TA2', and 'TA3' hereinafter for convenience of explanation.

[0506] The first TRP, which is a macro TRP, can instruct the UE to transmit a preset number of SRSs per TA to neighboring UL-only TRPs using TA1, TA2, and TA3 as TA values ​​for transmitting SRS(es). The UE, upon receiving this instruction, can transmit the SRSs based on the instruction of the first TRP. At this time, the UE can transmit the SRSs in various directions by changing the Joint / UL TCI state per TA while transmitting the SRSs.

[0507] The method for transmitting TA1, TA2, and TA3 described above to the UE by the macro TRP may utilize one or more of RRC, MAC-CE, and DCI. According to the 3GPP 5G NR standard, the TAC MAC CE may include a TA value field. In the present disclosure, a UL-only TRP indicator field may be added to enable recognition that the TA value indicated by the TA value field means a TA value between the UL-only TRP and the UE. In addition, the TA value field may be configured to express each of TA1, TA2, and TA3. The TAC MAC CE according to one embodiment of the present disclosure may include fields as shown in Table 1 below.

[0508] MAC CE Index Field UL Only TRP Indicator Field TA Value Field

[0509] Additionally, according to another embodiment of the present disclosure, the TAC MAC CE may further include a Joint / UL TCI status field, and may inform the UE of the TCI status to which each of the TA1, TA2, and TA3 values ​​applies. The TAC MAC CE further including the Joint / UL TCI status field may include fields as shown in Table 2 below.

[0510] MAC CE Index FieldJoint / UL TCI Status FieldTA Value Field

[0511] <ul 전용 trp 탐색 완료 시 ta 획득>

[0512] If the search for a UL-only TRP using the SRS is successful, that is, the UL-only TRP that properly receives the SRS transmitted by the UE can notify the search result to the first TRP, which is a macro TRP. Using this, the macro TRP can calculate a TA value between the UE and the UL-only TRP. In addition, the first TRP, which is a macro TRP, can notify the calculated TA value between the UE and the UL-only TRP using a TAC command. The UE can obtain the TA value with the UL-only TRP based on the TAC command received from the first TRP. Therefore, the UE can perform UL transmission using the TA value based on the TAC command when performing UL transmission using the UL-only TRP.

[0513] Figure 13 is a conceptual diagram illustrating a case where UL-only TRPs in an asymmetric mTRP environment transmit a given estimated value to the first TRP.

[0514] Referring to FIG. 13, a base station (1341) can communicate with a UE (1311) located within its cell using a plurality of TRPs (1301, 1302, 1303). In the example of FIG. 13, only three TRPs (1301, 1302, 1303) are illustrated for the sake of simplicity of the drawing, but the number of TRPs that can be included within the base station (1341) is not limited to three and may be more or less than three.

[0515] Also, in the embodiment of FIG. 13, it is assumed that three different TRPs are included in one base station (1341). A first TRP (1301) may have a first cell area (1110), a second TRP (1302) may have a second cell area (1320), and a third TRP (1303) may have a third cell area (1330). The first TRP (1301) illustrated in FIG. 13 may be referred to as a macro TRP or head TRP as described above, and may perform downlink (DL) and uplink (UL) transmission with a UE (1311). The second TRP (1302) and the third TRP (1303) may be uplink-only TRPs as described above. Therefore, the second TRP (1302) and the third TRP (1303) may be TRPs that do not transmit any signal in the downlink or TRPs that transmit only a minimal downlink signal.

[0516] The UE (1311) illustrated in FIG. 13 may be UE #0 described in FIGS. 10A and 10B and may be in an RRC-connected state with the first TRP (1301). The UE (1311) may be instructed to transmit an SRS or a preamble from the first TRP (1301). The UE (1311) may transmit the SRS or the preamble based on the number of UL signals beam-swept per set and the transmission time per set as instructed by the first TRP (1301) among the beam directions that the UE (1311) can set, as illustrated in FIG. 13.

[0517] When the UE performs beam sweeping as in the example in FIG. 12 or step S1040 of FIG. 10b, each of the UL-only TRPs (1302, 1303) can estimate the UL reception (Rx) power and reception timing corresponding to the PL based on the SRS / preamble spatially related to the UE. After estimating the UL reception power and reception timing, each of the UL-only TRPs (1302, 1303) can transmit the estimation results of the UL reception power and reception timing to the base station (1341) through the backhaul (1351, 1352) connected to each of the UL-only TRPs (1302, 1303) and the base station (1341), as illustrated in FIG. 13. And, the base station (1341) can transmit the UL reception power and reception timing received from each of the UL-only TRPs (1302, 1303) to the first TRP (1301) through the backhaul (1353) connected to the first TRP (1301). The transmission method through a wire as shown in FIG. 13 is an example and is not limited thereto. For example, if each of the UL-only TRPs (1302, 1303) can be wirelessly connected to the first TRP (1301), each of the UL-only TRPs (1302, 1303) can directly transmit the estimation results of the UL reception power and reception timing to the first TRP (1301). In the present disclosure, there is no particular restriction on the method by which the first TRP (1301) receives the estimation results of the UL reception power and reception timing from each of the UL-only TRPs (1302, 1303).

[0518] The first TRP (1301), which has received the estimation results of UL reception power and reception timing from each of the UL-only TRPs (1302, 1303), can compare the DL PL value and / or DL ​​reception timing value from the first TRP (1301) to the UE (1311), with the UL reception power values ​​and / or UL reception timing values ​​from the UE (1311) to the UL-only TRPs (1302 or 1303). Based on the comparison results, the first TRP (1301) can calculate (or estimate) PL offsets necessary for calculating transmission power values ​​when the UE (1311) transmits UL to each of the UL-only TRPs (1302, 1302) and TT offsets necessary for calculating UL transmission time points when the UE (1311) transmits UL to each of the UL-only TRPs (1302, 1303).

[0519] Here, if we describe the UL power control procedure including the PL offset, UL reception in a UL-only TRP without DL transmission must perform power control and TA based on the first TRP (1310). In this case, there may be a constraint on the maximum supported value of the difference between the distance between the first TRP and the UE (1311) and the distance between the UE (1311) and the UL-only TRP. This constraint may not always be a good solution. If there is no such constraint, the PL measured using the DL PL RS transmitted from the first TRP (1301) may not reflect the actual PL value from the UE (1311) to the UL-only TRP (1302 or 1303). In order to reflect the actual PL value, the difference between the DL PL from the first TRP (1301) to the UE (1311) and the UL PL from the UE (1311) to the UL-only TRP (1302 or 1303) may be required. The difference (PL offset) between the DL PL and the UL PL from the UE (1311) to the UL-only TRP (1302 or 1303) can be calculated as "PL offset = DL PL - UL PL".

[0520] Therefore, with regard to PL offsets, there is a need for regulations regarding how PL offsets are configured, how they relate to joint / UL TCI states, and how they are used for uplink power control. For example, a procedure for updating a single UL PL for a single joint / UL TCI state, i.e., for uplink power control, can be performed as follows.

[0521] (1) When a UE (1311) that wants to connect to one UL-only TRP (1302 or 1303) has activated one joint / UL TCI state by the first TRP (1301), but is not included in the active TCI state list of the current UE, or when the UE (1311) attempts an initial connection / connection to one UL-only TRP (1302 or 1303), the UL PL can be calculated as in the following mathematical expression 1.

[0522]

[0523] In mathematical expression 1, the PL offset received (or recognized) from the first TRP (1301) can be considered as the network that governs it. In addition, depending on the criteria for defining the PL offset, it can be defined as a plus (+) rather than a minus (-) in mathematical expression 1.

[0524] (2) When a UE (1311) that wants to connect to one UL-only TRP (1302 or 1303) activates one joint / UL TCI state by the first TRP (1301) and is included in the current active TCI state list, or when the UE (1311) continuously updates the UL PL after establishing the initial access / connection to one UL-only TRP (1302 or 1303), the UL PL can be updated from the immediately preceding UL PL as in Equation 2 below.

[0525]

[0526] In mathematical expression 2, the PL offset change value (Differential PL offset value) is the difference between the updated UL PL and the immediately preceding UL PL, and thus can be named a delta PL value, and this value can be recognized (or received) by the UE (1311) from the network.

[0527] Additionally, an example of the immediately preceding UL PL may be the difference between the PL offset received (or recognized) from the first TRP in the “DL PL estimated from the immediately preceding DL PL RS”, and the updated UL PL by applying this may be calculated as in the following mathematical expression 3.

[0528]

[0529] For example, in Equation 3, if one joint / UL TCI state is activated and is not included in the current list of active TCI states, the delta PL value may be set to 0 dB if dB-scaled or 1 if real-scaled.

[0530] In the UL power control procedure described above, the control information received from the network may be a PL offset and a differential PL offset value. There may be various ways in which the first TRP (1301) (or the network) transmits the control information received from the network and the joint / UL TCI state mapping information associated with the PL offset to the UE (1311). The method by which the control information and the joint / UL TCI state mapping information associated with the PL offset are transmitted will be further described below.

[0531] Additionally, the first TRP (1301) may calculate a TT offset required to calculate a transmission time point at which the UE (1311) transmits a UL signal to the UL-only TRP(s) (1302 and / or 1303) using the reception timing value of the first TRP (1301) and the reception timing values ​​received from the UL-only TRPs (1302, 1303). Here, the first TRP (1301) may calculate an absolute TA value when the UE (1311) transmits to the UL-only TRPs (1302, 1303), instead of the TT offsets, using the value and the estimated reception timing values ​​received from the UL-only TRPs (1302, 1303).

[0532] A procedure for determining the timing of transmission of a UE's transmission signal, including the TT offset, is described.

[0533] In a UL-only TRP without DL transmission, power control and TA must be performed based on the first TRP. In this case, there may be a constraint on the maximum supported value of the difference between the first distance between the first TRP and the UE and the second distance between the UE and the UL-only TRP. This constraint may not always be a good solution. If there is no such constraint, the transmission time of the UE's transmission signal received from the first TRP may not reflect the transmission time of the UE's transmission signal to the UL-only TRP. Here, the transmission time of the UE's transmission signal received from the first TRP may mean a TA value indicating the transmission time of the UE transmitting a signal to the first TRP.

[0534] To reflect the actual transmission timing to the UL-only TRP, a difference may be required between the transmission timing of the UE's transmission signal to the 1st TRP received from the 1st TRP and the reception timing at which the UE transmits the transmission signal to the UL-only TRP and the UL-only TRP receives the signal. In other words, a value such as the following mathematical expression 4 may be required.

[0535]

[0536] Regarding TT offsets, the configuration of the TT offset, its relationship to the joint / UL TCI state, and whether the TT offset will be used for UL power control may need to be specified. The procedure for updating a single UL TT for a single joint / UL TCI state is described below. In other words, the procedure for controlling UL transmission timing is described below.

[0537] (1) When a UE that wants to connect to one UL-only TRP activates one joint / UL TCI state by the first TRP but is not included in the active TCI state list of the current UE, or when a UE attempts an initial access / connection to one UL-only TRP, the UL TT can be calculated as in Equation 5 below.

[0538]

[0539] In Equation 5, the first TRP can be considered as the network that governs the TT offset received from the first TRP. Furthermore, depending on the criteria for defining the PL offset, it can be defined as a plus (+) instead of a minus (-) in Equation 5.

[0540] (2) When a UE that wants to connect to one UL-only TRP activates one joint / UL TCI state by the first TRP and is included in the current active TCI state list, or when the UE continuously updates the UL TT after establishing the initial access / connection to one UL-only TRP, the UL TT can be updated from the immediately preceding UL TT as in Equation 6 below.

[0541]

[0542] In Equation 6, the Differential TT offset value is the difference between the updated UL TT and the immediately preceding UL TT, and can therefore also be referred to as the delta TT value. The UE can receive the delta TT value from the network.

[0543] For example, if a joint / UL TCI state is activated and is not included in the current list of active TCI states, the delta TT value may be set to 0.

[0544] The operation described above may be such that the first TRP may generate the mapping information below based on the UL reception power and reception timing received from the UL-only TRPs in steps S1051 and S1052 of FIG. 10b described above. Then, the first TRP may transmit the mapping information to UE #0 in step S1060. The mapping information may be information to be transmitted to UE #0, and may be mapping information between PL offset, delta PL value and / or TT offset (or absolute TAs), delta TT values, UL TCI state / spatial relation and PL offset / delta PL values ​​(or TT offsets / delta TT values).

[0545] FIG. 14 is a conceptual diagram illustrating a case where a macro TRP in an asymmetric mTRP environment transmits mapping information calculated based on estimated values ​​received from UL-only TRPs to a UE.

[0546] Referring to FIG. 14, a base station (1441) can communicate with a UE (1411) located within its cell using a plurality of TRPs (1401, 1402, 1403). In the example of FIG. 14, only three TRPs (1401, 1402, 1403) are illustrated for the sake of simplicity of the drawing, but the number of TRPs that can be included within the base station (1441) is not limited to three and may be more or less than three.

[0547] Also, in the embodiment of FIG. 14, it is assumed that three different TRPs are included in one base station (1441). A first TRP (1401) may have a first cell area (1110), a second TRP (1402) may have a second cell area (1420), and a third TRP (1403) may have a third cell area (1430). The first TRP (1401) illustrated in FIG. 14 may be referred to as a macro TRP or head TRP as described above, and may perform downlink (DL) and uplink (UL) transmission with a UE (1411). The second TRP (1402) and the third TRP (1403) may be UL-only TRPs as described above. Therefore, the second TRP (1402) and the third TRP (1403) may be TRPs that do not transmit any signal in the downlink or may be TRPs that transmit only a minimal downlink signal.

[0548] The UE (1411) illustrated in FIG. 14 may be UE #0 described in FIGS. 10A and 10B, and may be in an RRC-connected state with the first TRP (1401). In FIG. 14, the first TRP (1401) may perform the operation of step S1060 as described above in FIG. 10B. In other words, the first TRP (1401) may generate mapping information based on UL reception power and reception timing received from UL-only TRPs, and may transmit the generated mapping information to the UE (1411). Here, the mapping information is information to be transmitted to the UE (1411), and may be mapping information between a PL offset, a delta PL value, and / or a TT offset (or absolute TAs), delta TT values, a UL TCI state / spatial relation, and PL offset / delta PL values ​​(or TT offsets / delta TT values).

[0549] Since each PL offset has a TT offset that is mapped one-to-one, the mapping information between the UL TCI state / space relationship and the PL offsets is the same as the mapping information between the UL TCI state / space relationship and the TT offsets.

[0550] When performing mapping between UL TCI states and PL offsets, the spatial relationship may mean a UL TCI state throughout the specification according to the present disclosure, or may also mean a joint TCI state or unified TCI state that combines a DL TCI state and a UL TCI state, as defined for efficiency.

[0551] Hereinafter, embodiments for the association between PL offset and joint / UL TCI state are described. Hereinafter, multiple embodiments for the association between PL offset and joint / UL TCI state are described, but in these embodiments, PL offset can be replaced with TT offset and delta PL value / differential TT offset value can be replaced with delta TT value, thereby multiple embodiments for the association between TT offset and joint / UL TCI state can be created. In addition, the embodiments described below can be extended by configuring PL offset difference value and TT offset value together, and configuring delta PL offset / differential PL offset value together with delta TT to increase resource utilization efficiency.

[0552] In the first embodiment, only one PL offset value can be configured within a single Joint / UL TCI state by RRC. While the first embodiment is simple, it may lack flexibility when dynamic adjustment is required.

[0553] In a second embodiment, one PL offset value is configured by RRC for one joint / UL TCI state, and one MAC CE can update one or more PL offset values ​​for the joint / UL TCI state(s).

[0554] A third embodiment is that a list of PL offset settings is configured by RRC in a bandwidth part (BWP) / component carrier (CC), each PL offset setting contains one PL offset value, and a new RRC parameter can be introduced within one joint / UL TCI state to recognize one of the configured PL offset settings.

[0555] In a fourth embodiment, a list of PL offset settings is set by RRC in BWP / CC, each PL offset setting includes one PL offset value, one new RRC parameter is set in one joint / UL TCI state to recognize one of the set PL offset settings, and one MAC CE can update the association between one joint / UL TCI state and the PL offset setting.

[0556] A fifth embodiment is that a list of PL offset settings is set by RRC in BWP / CC, each PL offset setting includes one PL offset value, and one MAC CE can activate or recognize one PL offset setting for each activated joint / UL TCI state.

[0557] A sixth embodiment is a list of PL offset values ​​provided to one joint / UL TCI state by RRC, and each PL offset value can be applied to its corresponding measured PL range.

[0558] A seventh embodiment provides that, in cases where the UE moves quickly and requires an update (e.g., high mobility) or the PL offset information received via RRC signaling is inaccurate, a UE that has completed initial system access to the first TRP of FIGS. 7A and 7B within a BWP / CC can receive a list of PL offset settings (or values) from the first TRP via RRC signaling. Embodiments thereof are described with reference to the drawings below.

[0559] Figure 15 is a conceptual diagram illustrating the relationship between PL offset settings required for uplink power control, delta PL settings, and TCI state settings.

[0560] Referring to FIG. 15, the initial delta PL configuration (1501) may include delta PL index 0 (0 dB), delta PL index 1 (a dB), delta PL index 2 (b dB), delta PL index 3 (c dB), …, the initial PL offset configuration (1511) may include PL offset index 1 (A dB), PL offset index 2 (B dB), PL offset index 2 (C dB), …, and the initial TCI state configuration (1521) may include TCI state 1, TCI state 2, ….

[0561] The delta PL index 0 (0 dB) of the initial delta PL setting (1501) may be associated with the PL offset index 1 (A dB) and the PL offset index 2 (B dB) of the initial PL offset setting (1511). In addition, the PL offset index 1 (A dB) and the PL offset index 2 (B dB) of the initial PL offset setting (1511) may be associated with the TCI state 1 and the TCI state 2 of the initial TCI state setting (1521), respectively.

[0562] For the above association, the MAC CE can inform the UE of the association between the PL index, the delta PL index, and the joint / UL TCI state. For a disabled TCI state, the delta PL index can be 0.

[0563] At this time, the initial PL offset setting (1511) may be updated as shown by reference numeral 1531. Based on the first update (1531), the delta PL setting (1502) may include delta PL index 1 (a dB), delta PL index 2 (b dB), delta PL index 3 (c dB), …, the PL offset setting (1512) may include PL offset index 1 (A dB), PL offset index 2 (B dB), PL offset index 2 (C dB), …, and the TCI state setting (1522) may include TCI state 1, TCI state 2, ….

[0564] Delta PL index 2 (b dB) of the delta PL setting (1502) may be associated with PL offset index 1 (A dB) of the PL offset setting (1512), and delta PL index 3 (c dB) of the delta PL setting (1502) may be associated with PL offset index 2 (B dB) of the PL offset setting (1512). Additionally, PL offset index 1 (A dB) of the PL offset setting (1512) may be associated with TCI state 1 of the TCI state setting (1522), and PL offset index 2 (B dB) may be associated with TCI state 2.

[0565] As shown in reference numeral 1532, the PL offset setting (1512) can be updated. Based on the second update (1532), the delta PL setting (1503) can include delta PL index 1 (a dB), delta PL index 2 (b dB), delta PL index 3 (c dB), …, the PL offset setting (1513) can include PL offset index 1 (A dB), PL offset index 2 (B dB), PL offset index 2 (C dB), …, and the TCI state setting (1523) can include TCI state 1, TCI state 2, ….

[0566] At this time, based on the second update (1532) with the PL offset setting (1513) as shown in reference numeral 1532, the delta PL index 1 (a dB) of the delta PL setting (1503) may be associated with the PL offset index 1 (A dB) of the PL offset setting (1513), and the delta PL index 2 (b dB) of the delta PL setting (1503) may be associated with the PL offset index 3 (C dB) of the PL offset setting (1513). In addition, the PL offset index 1 (A dB) of the PL offset setting (1513) may be associated with the TCI state 1 of the TCI state setting (1523), and the PL offset index 3 (C dB) may be associated with the TCI state 2.

[0567] A UE that receives mapping information in the manner described above can store a list of received mapping information. The above information can be transmitted to the UE by the first TRP, which is a macro TRP, via RRC signaling. The UE that receives the above information and the first TRP that obtains the PL offset values ​​between the target UL-only TRPs can map one PL offset setting (or value) from the PL offset setting list, as illustrated in FIG. 15, to a joint / UL TCI state corresponding to each of the UL-only TRPs, as illustrated in FIG. 15. The information mapped in this way can be transmitted to the UE via MAC CE(s).

[0568] If the PL offset settings (or values) in the setting list illustrated in FIG. 15 are not in the PL offset values ​​estimated by the first TRP, need to be updated, or have poor correlation, the first TRP (or network), which is a macro TRP, can be configured to recognize that the PL offset values ​​estimated by the MAC-CE(s) are not in the PL offset values ​​estimated by the first TRP, need to be updated, or have poor correlation. For this purpose, one or more bit information can be added to the MAC-CE(s), and a delta PL value, which is a difference value between the PL offset setting (or value) of one of the PL offset setting lists corresponding to the joint / UL TCI state and the PL offset value estimated (or obtained) by the first TRP, can be set.

[0569] One embodiment of selecting a PL offset setting (or value) at this time may select a PL offset setting (or value) that is closest to the PL offset value estimated (or acquired) by the first TRP. A specific embodiment thereof is described below.

[0570] A first detailed embodiment of the seventh embodiment described above is described with reference to the drawings below.

[0571] Fig. 16 is a conceptual diagram illustrating the setting of the first PL offset MAC CE of the seventh embodiment.

[0572] Referring to FIG. 16, it can be composed of octet 0 consisting of 1 byte, octet 1 consisting of 1 byte, and octet 2 consisting of 1 byte. In other words, it can be composed of a total of 3 octets (3 bytes). The first bit of octet 0 is a reserved bit(s) and can always be set to zero (0), the following 5 bits can be configured as a serving cell ID, and the last 2 bits can be set as a BWP ID. The first bit of octet 1 can be set as a TCI indicator, and the following 7 bits can be configured as a joint / UL TCI state ID. The first bit of octet 2 can be configured as an offset indicator, the following 5 bits can be configured as PL offset configuration ID 1, and the last 2 bits can be set to PL offset configuration ID 2.

[0573] As illustrated in FIG. 16, one MAC CE can configure two and / or more PL offset configuration IDs in one joint / UL TCI state. The first bit of octet 1, the TCI indicator, can indicate whether the following state ID is a joint TCI state ID or a UL TCI state. The first offset indicator of octet 2 can serve to indicate whether the PL offset configuration list received by RRC can be configured or not. If the PL offset configuration list received by RRC can be configured, this can be recognized because PL offset configuration ID 1 is one of the configuration lists. On the other hand, if the PL offset configuration list received by RRC cannot be configured, a value between the PL offset values ​​indicated by PL offset configuration ID 1 and PL offset configuration ID 2 can be configured. To reduce the number of bits occupied here, the TCI indicator can be omitted. Additionally, if the offset indicator is omitted altogether, it can be configured with only the PL offset setting ID, which is one of the setting lists.

[0574] Fig. 17 is a conceptual diagram illustrating the configuration of the second PL offset MAC CE of the seventh embodiment.

[0575] Referring to FIG. 17, it can be composed of octet 0 consisting of 1 byte, octet 1 consisting of 1 byte, octet 2 consisting of 1 byte, octet 3 consisting of 1 byte, octet 4 consisting of 1 byte, and octet 5 consisting of 1 byte. In other words, it can be composed of a total of 6 octets (6 bytes).

[0576] The first bit of octet 0 is a reserved bit(s) and can always be set to zero (0), the following 5 bits can be configured as a serving cell ID, and the last 2 bits can be set as a BWP ID. The first bit of octet 1 can be configured as a TCI indicator, and the following 7 bits can be configured as a joint / UL TCI state ID 0. The first bit of octet 2 can be configured as an offset indicator, and the following 3 bits can be configured as a PL offset configuration ID 00, the following 3 bits as a PL offset configuration ID 01, the following PL offset configuration ID 2, and the last 1 bit can be configured as a next indicator 0. The first bit of octet 3 may be set as a reserved bit(s), the following 5 bits may be configured as a serving cell ID 1, and the last 2 bits may be set as a BWP ID 1. The first bit of octet 4 may be set as a TCI indicator, and the following 7 bits may be configured as a joint / UL TCI status ID 1. The first bit of octet 5 may be configured as an offset indicator, the following 3 bits may be configured as a PL offset configuration ID 10, the following 3 bits may be configured as a PL offset configuration ID 11, and the last 1 bit may be configured as a next indicator 1.

[0577] As illustrated in FIG. 17, one MAC CE can configure two and / or more PL offset configuration IDs per joint / UL TCI state. The TCI indicator illustrated in FIG. 17 indicates whether the following TCI state is joint TCI state ID 0 or UL TCI state ID 0, and the offset indicator can indicate whether it is configurable with the PL offset configuration list received by RRC or not. If it is configurable with the PL offset configuration list received by RRC, the PL offset configuration ID 00 can be indicated because it is one of the configuration lists. On the other hand, if it is not configurable with the PL offset configuration list received by RRC, the PL offset values ​​indicated by the PL offset configuration ID 00 and the PL offset configuration ID 01 can be set to a value between the PL offset values ​​indicated by the PL offset configuration ID 00 and the PL offset configuration ID 01. The example of FIG. 17 can be repeatedly set by performing these operations. More specifically, the configuration of octets 3 to 5 may be a repetition of octets 0 to 2. In the example of Fig. 17, the TCI indicator and offset indicator may be omitted to reduce the number of bits.

[0578] Fig. 18 is a conceptual diagram illustrating the configuration of the third PL offset MAC CE of the seventh embodiment.

[0579] Referring to FIG. 18, it can be composed of octet 0 consisting of 1 byte, octet 1 consisting of 1 byte, and octet 2 consisting of 1 byte. In other words, it can be composed of a total of 3 octets (3 bytes). The first bit of octet 0 can be set as a reserved bit(s), the subsequent 5 bits can be configured as a serving cell ID, and the last 2 bits can be set as a BWP ID. The first bit of octet 1 can be set as a TCI indicator, and the subsequent 7 bits can be configured as a joint / UL TCI state ID. The first bit of octet 2 can be configured as an offset indicator, the subsequent 4 bits can be configured as a PL offset configuration ID, and the last 3 bits can be set as a differential PL offset value.

[0580] As illustrated in Fig. 18, one MAC CE may be configured with one PL offset setting ID and a PL offset change value (Differential PL Offset Value) per joint / UL TCI state. Here, the PL offset change value (Differential PL Offset Value) may correspond to the Delta PL value described above, and may be a Delta PL index indicating the Delta PL value as described in Fig. 15 to reduce the number of bits.

[0581] The TCI indicator can indicate whether the following TCI state is Joint TCI State ID 0 or UL TCI State 0.

[0582] The offset indicator can indicate whether the PL offset setting list received by RRC can be set or not set with the PL offset setting list received by RRC. If the PL offset setting list received by RRC can be set, the PL offset setting ID can indicate this because it is one of the setting lists. On the other hand, if the PL offset setting list received by RRC cannot be set, the PL offset value for the TCI state can be set by combining the PL offset value indicated by the PL offset setting ID with a PL offset change value (Differential PL Offset Value). Here, the PL offset change value (Differential PL Offset Value) can mean a difference value between the PL offset value of one PL offset setting in the setting list and an actually estimated (or acquired) PL offset value. However, the present disclosure is not limited thereto.

[0583] When the PL offset value is mapped to the initial value of the Differential PL offset value or the deactivated TCI state, it can be 0 dB, such as the delta PL index 0 of the delta PL setting in FIG. 15. In addition, the TCI indicator and offset indicator can be omitted as described above to reduce the number of bits transmitted via MAC-CE.

[0584] Fig. 19 is a conceptual diagram illustrating the configuration of the fourth PL offset MAC CE of the seventh embodiment.

[0585] Referring to FIG. 19, it can be composed of octet 0 consisting of 1 byte, octet 1 consisting of 1 byte, octet 2 consisting of 1 byte, octet 3 consisting of 1 byte, octet 4 consisting of 1 byte, and octet 5 consisting of 1 byte. In other words, it can be composed of a total of 6 octets (6 bytes).

[0586] The first bit of octet 0 is a reserved bit(s) and can always be set to zero (0), the following 5 bits can be configured as a serving cell ID, and the last 2 bits can be set as a BWP ID. The first bit of octet 1 can be set as a TCI indicator, and the following 7 bits can be configured as a joint / UL TCI state ID 0. The first bit of octet 2 can be configured as an offset indicator, the following 3 bits can be configured as a PL offset configuration ID 00, the following 3 bits can be configured as a different PL offset value after the PL offset configuration ID 01, and the last 1 bit can be configured as a next indicator 0. The first bit of octet 3 may be set as a reserved bit(s), the following 5 bits may be configured as a serving cell ID 1, and the last 2 bits may be set as a BWP ID 1. The first bit of octet 4 may be set as a TCI indicator, and the following 7 bits may be configured as a joint / UL TCI status ID 1. The first bit of octet 5 may be configured as an offset indicator, the following 3 bits may be configured as a PL offset configuration ID 10, the following 3 bits may be configured as another PL offset value, and the last 1 bit may be configured as a next indicator 1.

[0587] As illustrated in Fig. 17, one MAC CE can configure one PL offset setting ID and a PL offset change value (Differential PL Offset Value) per joint / UL TCI state. Here, the PL offset change value (Differential PL Offset Value) can correspond to the delta PL value described above. Instead of the PL offset change value, a delta PL index indicating the delta PL value can be used as illustrated in Fig. 15 to reduce the number of bits transmitted through the MAC-CE.

[0588] The TCI indicator can indicate whether the following TCI state is Joint TCI state ID 0 or UL TCI state 0. The offset indicator can indicate whether the PL offset configuration list received via RRC can be configured or not. If the PL offset configuration list received via RRC can be configured, the PL offset configuration ID 00 can be indicated since it is one of the configuration lists. On the other hand, if the PL offset configuration list received via RRC cannot be configured, the PL offset value for the corresponding TCI state can be configured by combining the PL offset value indicated by the PL offset configuration ID 00 with the Differential PL Offset Value 00. Here, the Differential PL Offset Value 00 can mean the difference value between the PL offset value of one of the PL offset configurations in the configuration lists and the actually estimated (or acquired) PL offset value. However, the present disclosure is not limited thereto.

[0589] When the PL offset value is mapped to the initial value of the Differential PL offset value or the deactivated TCI state, it can be 0 dB, such as the delta PL index 0 of the delta PL setting in FIG. 15. In addition, the TCI indicator and offset indicator can be omitted as described above to reduce the number of bits transmitted via MAC-CE.

[0590] Fig. 19 can also be understood as a form in which three octets are repeatedly set. Here, when mapped to the initial value of the PL offset change value (Differential PL offset value) or the disabled TCI state, it can be 0 dB, like the delta PL index 0 of the delta PL setting in Fig. 15. In addition, the TCI indicator and offset indicator can be omitted as described above to reduce the number of bits transmitted via MAC-CE.

[0591] As an 8th embodiment, there is a need to prepare for cases where the UE moves quickly and requires an update (e.g., high mobilities) or where the PL offset information received via RRC signaling is inaccurate.

[0592] In the present disclosure, the operation of a UE that has completed initial connection to a first TRP, which is a macro TRP, as described in FIGS. 7A and 7B within a BWP / CC is described when PL offset information received via RRC signaling is incorrect. The UE that has completed initial connection to the first TRP, which is a macro TRP, can receive a list of N PL offset settings (or values) from the first TRP via RRC signaling. An example of this is the PL offset configuration of FIG. 15. The UE that has received the list of N PL offset settings from the first TRP via RRC signaling can store it. Here, the UE can store the list of delta PL settings (configurations) as exemplified in FIG. 15 described above from the first TRP via RRC signaling.

[0593] The first TRP, which estimates (or obtains) PL offset values ​​between the UE and target UL-only TRPs, can map one PL offset setting (or value) from the PL offset setting list to a joint / UL TCI state corresponding to each UL-only TRP, as illustrated in FIG. 15, and transmit the mapped information to the UE by setting it in one DCI.

[0594] If the PL offset settings (or values) in the list of settings described above are not among the PL offset values ​​estimated (or obtained) by the first TRP, or need to be updated, or have poor correlation, the first TRP (or the network) may add one or more bit information to the DCI to enable it to recognize this. The bit information added to the DCI may set a difference value between one PL offset setting (or value) in the list of PL offset settings corresponding to the joint / UL TCI state and the PL offset value estimated by the first TRP. In other words, a delta PL value may be set. In this case, one embodiment of selecting one PL offset setting (or value) may select a PL offset setting (or value) that is closest to the PL offset value estimated by the first TRP.

[0595] Below, detailed embodiments for the eighth embodiment are described.

[0596] First, the first detailed embodiment of the eighth embodiment is described.

[0597] The UE may receive a list of PL offset configurations received via RRC signaling. In other words, the first TRP may transmit the list of PL offset configurations received via RRC signaling to the UE. In addition, the first TRP may transmit two PL offset configuration indices adjacent to the PL offset value to be applied to the UE, including them in the DCI to be transmitted to the UE. Table 3 below may be an example of a DCI format for a PDCCH order among multiple DCI formats.

[0598] DCI Field Number of bits for PDCCH order Identifier for DCI formats 1 Frequency-domain resource allocation Variable random access preamble index 6 UL / SUL indicator 1 SS / PBCH indicator 6 PRACH mask index (e.g., RO associated with SS / PBCH indicated by SS / PBCH) 4 PL offset configuration 1 index a PL offset configuration 2 index b Reserved bits C

[0599] As illustrated in Table 3, a PL offset setting 1 index and a PL offset setting 2 index may be assigned within the DCI fields. A UE that receives a PDCCH order may transmit a PRACH preamble to the corresponding TRP by applying a PL offset value indicated by the PL offset setting index 1, transmit a PRACH preamble to the corresponding TRP by applying a PL offset value indicated by the PL offset setting index 2, or transmit a PRACH preamble to the corresponding TRP by applying a value between the PL offset values ​​indicated by the PL offset setting index 1 and the PL offset setting index 2. The identifier for DCI formats field value is always 1 and may indicate a downlink. In Table 3, all bit values ​​of the frequency domain resource assignment field may be set to 1, and the random access preamble index may indicate an index of a preamble for random access. The UL / Supplementary Uplink (SUL) indicator can indicate UL if the field information value is 0, and can mean SUL if the field information value is 1. The UL / SUL indicator can indicate the UL carrier of the cell on which the PRACH will be transmitted if the random access preamble index bit values ​​are not all 0 and the UE is configured with supplementary uplink in the serving cell configuration (ServingCellConfig) of the cell.

[0600] Also, in Table 3, the SS / PBCH index may mean the beam index of the Synchronization Signal Block (SSB), and the PRACH mask index may mean the RO associated with the SS / PBCH indicated by the SS / PBCH index. It should be noted here that Table 3 is an example of a DCI format for a PDCCH order, and the PL offset setting 1 index and the PL offset setting 2 index presented in Table 3 can be assigned to all other possible DCI formats.

[0601] Additionally, instead of the SS / PBCH indices in Table 3, beam indices and TRP indices or Joint / UL TCI states required for efficient system access can be assigned. Additionally, only one PL offset setting index can be configured, and when the first TRP instructs the UE to perform beam sweeping using PRACH preamble(s), as another method for transmitting the beam sweeping instruction to the UE, after the first TRP and the UE complete RRC reconfiguration, the first TRP can transmit DCI to the UE in the form of a PDCCH order to instruct the UE to perform beam sweeping.

[0602] Next, the second detailed embodiment of the eighth embodiment is described.

[0603] The UE may receive a list of PL offset configurations received via RRC signaling. In other words, the first TRP may transmit the list of PL offset configurations received via RRC signaling to the UE. In addition, the first TRP may include one PL offset configuration index adjacent to the PL offset value to be applied to the UE and a differential PL offset index / value in the DCI to be transmitted to the UE. Table 4 below may be an example of a DCI format for a PDCCH order among multiple DCI formats.

[0604] DCI Field Number of bits for PDCCH order Identifier for DCI formats 1 Frequency-domain resource allocation Variable random access preamble index 6 UL / SUL indicator 1 SS / PBCH indicator 6 PRACH mask index (e.g., RO associated with SS / PBCH indicated by SS / PBCH) 4 PL offset configuration index a PL offset index / value difference b Reserved bits C

[0605] In Table 4, the PL offset configuration index and the Differential PL offset index / value may be assigned within the DCI fields. A UE that receives a PDCCH order may transmit a PRACH preamble to the corresponding TRP by applying a value that combines (for example, adds) the PL offset value indicated by the PL offset configuration index and the value indicated by the Differential PL offset index / value. In Table 4, the identifier for DCI formats field value may always be set to 1 and may indicate downlink. All bit values ​​of the frequency domain resource assignment field may be set to 1. The random access preamble index field may indicate the index of a preamble for random access. The UL / Supplementary Uplink (SUL) indicator can indicate UL if the field information value is 0, and can mean SUL if the field information value is 1. The UL / SUL indicator can indicate the UL carrier of the cell on which the PRACH will be transmitted if the random access preamble index bit values ​​are not all 0 and the UE is configured with supplementary uplink in the serving cell configuration (ServingCellConfig) of the cell.

[0606] In Table 4, the SS / PBCH index may indicate the beam index of SSB. The PRACH mask index may indicate the RO associated with the SS / PBCH recognized by the SS / PBCH index. Here, Table 4 is an example of a DCI format for a PDCCH order, and the PL offset 1 index (offset configuration 1 index) and the PL offset configuration 2 index (PL offset configuration 2 index) exemplified in Table 3 may be assigned to all other possible DCI formats. In addition, instead of the SS / PBCH index in Table 3, the beam index and TRP index required for efficient system access may be assigned.

[0607] Next, the third detailed embodiment of the eighth embodiment is described.

[0608] The UE can receive a list of PL offset configurations received via RRC signaling. In other words, the first TRP can transmit the list of PL offset configurations received via RRC signaling to the UE. The first TRP can transmit a list of PL offset configurations corresponding to the UE from the list of PL offset configurations transmitted via RRC signaling to the UE via MAC CE. The MAC CE can transmit a joint TCI state / UL TCI state associated with the PL offset configuration list transmitted to the UE via RRC signaling. The UE can receive the joint TCI state / UL TCI state associated with the PL offset configuration list via the MAC CE. When transmitting a signal (or channel) to the uplink, the UE can check the PL offset value and the joint TCI state / UL TCI state related thereto based on the MAC CE received from the first TRP. Thereafter, the first TRP can indicate the joint TCI state / UL TCI state via DCI transmitted to the UE.

[0609] Table 5 below is an example of the configuration of a DCI format for a PDCCH order among multiple DCI formats transmitted to a UE.

[0610] DCI Fields Number of bits for PDCCH order Identifiers for DCI formats 1 Frequency-domain resource allocation Variable random access preamble index 6 UL / SUL indicator 1 SS / PBCH indicator 6 PRACH mask index (e.g., RO associated with SS / PBCH indicated by SS / PBCH) 4 Joint TCI status / UL TCI status a Reserved bits b

[0611] Table 5 may be an example of a joint TCI state / UL TCI state being allocated within DCI fields. A UE that receives a PDCCH order as exemplified in Table 5 may transmit a PRACH preamble to the corresponding TRP by applying the PL offset value indicated by the joint TCI state / UL TCI state. In Table 5, the identifier for DCI formats field value may always be 1 and may indicate downlink. All bit values ​​of the frequency domain resource assignment field may be 1. The random access preamble index field may indicate the index of a preamble for random access. The UL / Supplementary Uplink (SUL) indicator may indicate UL when the field information value is 0, and may indicate SUL when the field information value is 1. The UL / SUL indicator may indicate the UL carrier of the cell on which the PRACH will be transmitted if the random access preamble index bit values ​​are not all 0 and the UE is configured with supplementary uplink in the serving cell configuration (ServingCellConfig) of the cell.

[0612] In Table 5, the SS / PBCH index may indicate the beam index of the SSB. The PRACH mask index may indicate the RO associated with the SS / PBCH recognized by the SS / PBCH index. Table 5 is an example of a DCI format for a PDCCH order, and the joint TCI state / UL TCI state presented in Table 5 can be assigned to all other possible DCI formats. In addition, instead of the SS / PBCH index, the beam index and TRP index required for efficient system access can be assigned.

[0613] Next, the fourth detailed embodiment of the eighth embodiment is described.

[0614] The UE can receive a PL offset configuration list and / or a delta PL value (delta PL value) configuration list and / or a PL offset configuration list received via RRC signaling. In other words, the first TRP can transmit the PL offset configuration list and / or the delta PL value (delta PL value) configuration list and / or the PL offset configuration list received via RRC signaling to the UE. And the first TRP can transmit to the UE, through RRC and / or MAC-CE, a joint TCI state / UL TCI state, etc. associated with the PL offset configuration list and / or the delta PL value (delta PL value) configuration list and / or the PL offset configuration list corresponding to the UE, among the PL offset configuration list and / or the delta PL value (delta PL value) configuration list and / or the PL offset configuration list transmitted to the UE via RRC. Accordingly, the UE may receive a joint TCI state / UL TCI state, etc. associated with the PL offset setting list and / or the delta PL value (delta PL value) setting list and / or the PL offset setting list from the first TRP via RRC and / or MAC-CE.

[0615] Afterwards, the first TRP may transmit a PDCCH order having additional fields to the UE. The PDCCH order may be, for example, DCI format 1_0. The DCI format 1_0 for the PDCCH order having additional fields may further include one or more of an Asym indicator, a joint TCI state / UL TCI state, a PL offset setting index, and / or a delta PL value index. In this case, the DCI field (or DCI format) may be present when a corresponding RRC parameter (a new RRC parameter configuring the presence of the added 1-bit DCI field (e.g., the Asym indicator field)) is activated and at least one TCI state is set to a PL offset.

[0616] Table 6 below is an example of the configuration of a DCI format for a PDCCH order among multiple DCI formats transmitted to a UE according to the fourth detailed embodiment of the eighth embodiment.

[0617] DCI Fields Number of bits for PDCCH order Identifiers for DCI formats 1 Frequency-domain resource allocation Variable random access preamble index 6 UL / SUL indicator 1 SS / PBCH indicator 6 PRACH mask index (e.g., RO associated with SS / PBCH indicated by SS / PBCH) 4 Asymmetric indicator 1 Joint TCI status / UL TCI status a PL offset setting index Delta PL value index b Reserved bits c

[0618] A UE that receives a PDCCH order as shown in Table 6 can transmit a PRACH preamble with a UL-only TRP by applying a PL offset value indicated by a PL offset setting index and a delta PL value indicated by a delta PL value index to a joint TCI state / UL TCI state indicated by the format of the PDCCH order as shown in Table 6.

[0619] In Table 6, the identifier field value for the DCI formats can always be 1 and can indicate downlink. All bit values ​​of the frequency domain resource allocation field can be 1. The random access preamble index can indicate the index of the preamble for random access. The UL / Supplementary Uplink (SUL) indicator can indicate UL when the field information value is 0, and can indicate SUL when the field information value is 1. The UL / SUL indicator can indicate the UL carrier of the cell on which the PRACH will be transmitted if the random access preamble index bit values ​​are not all 0 and the UE is configured with supplementary uplink in the serving cell configuration (ServingCellConfig) of the cell.

[0620] In Table 6, the SS / PBCH index may indicate the beam index of the SSB. The PRACH mask index may indicate the RO associated with the SS / PBCH recognized by the SS / PBCH index. In addition, the Asym indicator field may indicate whether the DCI format for the PDCCH order is an asymmetric mTRP scenario situation or not. For example, if the bit value of the Asym indicator field is 0, it may indicate a symmetric mTRP scenario situation. If the bit value of the Symmetric Asymmetry Indicator field indicates a symmetric mTRP scenario situation, the consecutive fields, namely, the Joint TCI State / UL TCI State, the PL Offset Setting Index, and the Delta PL Value Index, may be ignored.

[0621] On the other hand, if the bit value of the asymmetric indicator field is 1, it can indicate an asymmetric mTRP scenario situation. If the bit value of the symmetric asymmetric indicator field indicates an asymmetric mTRP scenario situation, the subsequent fields, i.e., joint TCI state / UL TCI state, can indicate an uplink transmission beam direction required when transmitting a PRACH preamble to the corresponding UL-only TRP as described above. In addition, if the bit value of the symmetric asymmetric indicator field indicates an asymmetric mTRP scenario situation, the PL offset setting index and / or the delta PL value index can indicate a PL offset value and / or a delta PL value received in advance by MAC-CE / RRC signaling, respectively.

[0622] Here, to use resources efficiently, if the asymmetric indicator is 1, the UL / SUL indicator and / or SS / PBCH index and / or other existing fields (e.g., the 1-bit PRACH association indicator field newly added to the 3GPP Rel-18 standard, etc.) can be reused. If the existing fields can be reused, all or part of the fields used in the asymmetric mTRP scenario situation in Table 6, for example, the joint TCI state / UL TCI state and / or the PL offset setting index and / or the delta PL value index, can be allocated and used.

[0623] If existing fields can be reused, but not all fields used in an asymmetric mTRP scenario situation can be allocated, the field information that was not allocated to the UL / SUL indicator and SS / PBCH index among the joint TCI state / UL TCI state, PL offset setting index, and delta PL value index can be allocated.

[0624] Additionally, one or more of the UL / SUL indicators, SS / PBCH indices, or other existing fields (e.g., PRACH association indicator field, etc.) may be reused to assign a PL offset setting (value indicating) index and / or a delta PL value index.

[0625] Additionally, one of the reasons for reusing existing fields or adding one or more of the new Joint TCI State / UL TCI State, PL Offset Setting Index, or Delta PL Value Index may be to clarify that there may not be only one UL-only TRP that the first TRP instructed the UE to attach.

[0626] As a variant embodiment, only the asymmetric indicator and the joint TCI status / UL TCI status fields in Table 6 may be added, and the remaining PL offset setting index and delta PL value index may be excluded. In another variant embodiment, if the number of bits in the reuse field below Table 6 is sufficient, only the asymmetric indicator field may be added, and the remaining joint TCI status / UL TCI status, PL offset setting index, and delta PL value index may be excluded.

[0627] If the asymmetric indicator field value is 1, the UL / SUL indicator and SS / PBCH index fields can be recycled to specify that these 7 bits contain joint TCI status / UL TCI status information, or that they contain joint TCI status / UL TCI status, PL offset setting index, or that they contain joint TCI status / UL TCI status, PL offset setting index, or delta PL value index information.

[0628] One example of a variation of Table 6 can be illustrated as in Table 7.

[0629] DCI field Number of bits for PDCCH order Identifier for DCI formats 1 Frequency-domain resource allocation Variable random access preamble index 6 UL / SUL indicator 1 SS / PBCH indicator 6 PRACH mask index (e.g., RO associated with SS / PBCH indicated by SS / PBCH) 4 Asymmetric indicator 1 Reserved bits a

[0630] First, DCI format 1_0 can be used which additionally includes a PRACH associated indicator field in Table 7. This DCI format in Table 7 can be present when the corresponding RRC parameter (a new RRC parameter configuring the presence of an Asymmetric Indicator field consisting of 1 bit in the DCI format) is activated and at least one TCI state is configured with a PL offset. For example, in 3GPP Rel-17 unified TCI, when one joint TCI state / UL TCI state is indicated, a bit value '0' in the Asymmetric Indicator field can indicate that the PL offset is not included in the PRACH transmit power calculation. On the other hand, a value '1' in the Asymmetric Indicator field can indicate that the PL offset associated with the TCI state indicated from the RRC and / or MAC CE message is included in the PRACH transmit power.

[0631] As mentioned above, when the value of the Asymmetric Indicator field is '1', it may mean that the PRACH preamble is transmitted as a UL-only TRP. For example, one or more of the UL / SUL indicator, SS / PBCH index, PRACH association indicator or other unused field(s) configured in the DCI format may be reused to indicate to the UE one or more of the following field information: a transmit beam pointing in the direction where the UL-only TRP is located, a joint TCI state / UL TCI state / integrated TCI state corresponding to the transmit beam, a PL offset obtained from an RRC / MAC-CE message, a delta PL value index, a Transmit Power Control (TPC) indicating an increase or decrease in transmit power when retransmitting the transmitted PRACH preamble, or any other possible field information.

[0632] Here, if the value of the asymmetric indicator field is '1', the first TRP may transmit to the UE one or more of the beam directions, time / frequency resource information, and transmit power / transmit power increase / decrease information of preambles transmitted to unknown UL-only TRP(s) after the initial UE establishes a connection with the first TRP, by using one or more of the bits of the reused UL / SUL indicator, SS / PBCH index, PRACH association indicator, or other unused field(s).

[0633] Meanwhile, for the asymmetric indicator field consisting of 1 bit of DCI 1_0 indicating PL offset application for PDCCH ordered PRACH transmission when two joint TCI states / UL TCI states are indicated in the unified TCI specified in 3GPP Rel-18 (i.e., when receiving an RRC / MAC-CE parameter / message containing indicated joint TCI state / UL TCI state information associated with each PL offset), a bit field index of 0 indicating unified TCI indicates that the PL offset associated with the first indicated joint TCI state / UL TCI state is included in the PRACH transmit power calculation. On the other hand, a bit field index of 1 indicating unified TCI indicates that the PL offset associated with the second indicated joint TCI state / UL TCI state is included in the PRACH transmit power calculation.

[0634] And as explained above, if the value of the field indicating the integrated TCI is '0', it may mean that the PRACH preamble is transmitted in the first UL-only TRP specified in the RRC / MAC CE parameter / message. For example, one or more of the UL / SUL indicator, SS / PBCH index, PRACH association indicator or other unused field(s) configured in the DCI format may be reused. If one or more field(s) are reused, the first TRP may indicate one or more of the following information: a transmit beam indicating the direction in which the UL-only TRP is located to the UE, a joint TCI state / UL TCI state / integrated TCI state corresponding to the transmit beam, a PL offset obtained from an RRC / MAC-CE message, a delta PL value index, a TPC indicating an increase or decrease in transmit power when retransmitting the transmitted PRACH preamble, or any other possible information.

[0635] Meanwhile, if the value of this field is '1', it may mean that the PRACH preamble is transmitted in the second UL-only TRP specified in the RRC / MAC CE parameter / message. For example, one or more of the UL / SUL indicator, SS / PBCH index, PRACH association indicator or other unused field(s) set in the DCI format may be reused. If one or more field(s) are reused, the first TRP may indicate to the UE, using the reused field(s), a transmit beam indicating the direction in which the UL-only TRP is located, a joint TCI state / UL TCI state / integrated TCI state corresponding to the transmit beam, a PL offset obtained from an RRC / MAC-CE message, a delta PL value index, a TPC indicating an increase or decrease in transmit power when retransmitting the transmitted PRACH preamble, or any other possible information.

[0636] Additionally, when the value of the asymmetric indicator field is '0' or '1', the first TRP may transmit to the UE one or more of the beam directions of the preambles transmitted to unknown UL-only TRP(s), their time / frequency resource information, and transmit power / transmit power increase / decrease information using bits of one or more fields of the reused UL / SUL indicator, SS / PBCH index, PRACH association indicator, or other unused field(s). At this time, the UE may be in a state where an initial connection is established with the first TRP.

[0637] Next, the fifth detailed embodiment of the eighth embodiment is described.

[0638] As illustrated in FIG. 15 described above, the UE may receive a MAC CE in which the association of a joint TCI state / UL TCI state mapped to a PL offset configuration list and / or a delta PL index / value list is updated. Thereafter, as illustrated in Table 8 below, the first TRP may transmit to the UE, through a DCI for a PDCCH order, the same or similar joint TCI state / UL TCI state, sweeping / repetition number, RO configuration, etc. associated with the PL offset and delta PL as illustrated in FIG. 15, together with an Asym mTRP indication. The DCI for a PDCCH order according to the fifth detailed embodiment of the eighth embodiment of the present disclosure may be configured as illustrated in Table 8 below.

[0639] Identifier field for DCI formats Frequency-domain resource allocation field Random access preamble index field PRACH RO index field PCI index field… Asynchronous mTRP indication field (2 bits): 00 (legacy), 01 (initial), 10 (non-initial), 11 (reserved) Sweep / repeat count field RO configuration field Joint TCI status / UL TCI status field Reserved bits field

[0640] An example of the bits in the Asym mTRP indication field can be set as follows:

[0641] (1) A UE that receives a PDCCH order can transmit a preamble as in the legacy case if the bit of the asynchronous mTRP indication is '00'. More specifically, if the bit of the asynchronous mTRP indication is '00', the UE can transmit a preamble at a given frequency location, that is, at a time / frequency location indicated by a given PRACH RO index in the frequency-domain resource assignment information, as in the preamble transmission example of the PDCCH order applied as the baseline. In addition, the preamble can be configured based on a random access preamble index included in the PDCCH order. The direction in which the preamble is transmitted can be transmitted in a direction indicated by the SS / PBCH index included in the PDCCH order.

[0642] (2) If the bit of the asynchronous mTRP indication included in the PDCCH order is '01', the UE may determine that the state is an initial UL-only TRP connection state. Accordingly, the UE may transmit a preamble to the UL-only TRP through a predetermined number of sweeping and / or repeating beams (e.g., corresponding to the Sweeping / repetition number field illustrated in Table 6 or Table 8). The transmission power of the beams through which the preamble is transmitted may be applied as a predetermined or arbitrary transmission power in the initial system connection procedure between the first TRP and the UE.

[0643] The transmission timing of the beams through which the preamble is transmitted may be transmitted in one or more ROs among the PRACH ROs (e.g., the RO configuration field of Table 8) that the first TRP has transmitted to the UE using RRC and / or MAC CE. Here, the RO configuration may not mean a single RO, but a grouping configuration list when multiple ROs are grouped. The number of ROs in the grouping configuration list may correspond to the Sweeping / repetition number field. In addition, the preamble transmitted through the beams may be a preamble generated based on a random access preamble index included in the PDCCH order as shown in Table 8.

[0644] As described above, for the transmitted sweeping and / or repeated preambles, the UE does not set a RAR window timer for RAR reception. In other words, the UE does not receive the RAR and may not perform preamble retransmission.

[0645] (3) If the bit of the asynchronous mTRP indication that has received the PDCCH order is '10', the UE may determine that the system connection state is non-initial. If the system connection state is determined to be non-initial, the UE may transmit a preamble in the direction indicated by the joint TCI state / UL TCI state received via MAC CE or RRC. At this time, the transmission power of the preamble may be calculated using the UL PL calculated by the mathematical expressions 2 and / or 3 described above.

[0646] The frequency location at which the preamble is transmitted can be determined based on frequency domain resource allocation information, and the time resource can be determined by the PRACH RO index field. Additionally, the transmitted preamble can be generated based on the random access preamble index. Accordingly, the generated preamble can be transmitted as a UL-only TRP in the time / frequency resources indicated by the PDCCH order in Table 8.

[0647] In order to reduce the number of DCI format bits of the PDCCH order illustrated in Table 8 in the fifth detailed embodiment of the eighth embodiment described above, one or more of the Sweeping / Repetition Number field and the RO Configuration field may be omitted. If one or more of the two fields is omitted, it may be stipulated that the information of the omitted fields is transmitted to the UE via MAC CE and / or RRC signaling.

[0648] In addition, when a new PDCCH order format for the asymmetric mTRP mode is defined separately from the existing and / or baseline PDCCH order formats, the fields in the new DCI format may be composed of an indicator field for DCI formats, a frequency-domain resource allocation field, a random access preamble index field, a PRACH RO index field, a PCI index field, an asynchronous mTRP indication field (2 bits) (the bit value may be set to, for example, 0 (initial) or 1 (non-initial)), a sweeping / repetition count field, an RO configuration field, a joint TCI status / UL TCI status field, a reserved bits field, etc. Here, bit '0' of the asynchronous mTRP indication field may follow the description of bit '01' of the asynchronous mTRP indication field described in Table 8, and bit '1' of the asynchronous mTRP indication field may follow the description of bit '10' described in Table 8.

[0649] Next, the sixth detailed embodiment of the eighth embodiment is described below.

[0650] As illustrated in FIG. 15 described above, the UE may receive a MAC CE in which the association of a joint TCI state / UL TCI state mapped to a PL offset configuration list and / or a delta PL index / value list is updated. The UE may indicate or activate the association of a joint TCI state / UL TCI state mapped to a PL offset configuration list and / or a delta PL index / value list based on the received MAC CE.

[0651] Hereafter, as shown in Table 9, the first TRP may be transmitted to the UE through DCI for a PDCCH order including an asynchronous mTRP indication, a sweeping / repetition number, RO configuration, etc. According to the sixth detailed embodiment of the eighth embodiment of the present disclosure, the DCI for a PDCCH order may be configured as shown in Table 9 below.

[0652] DCI Field Number of bits for PDCCH order Identifier for DCI formats 1 Frequency-domain resource allocation Variable random access preamble index 6 UL / SUL indicator 1 SS / PBCH indicator 6 PRACH mask index (e.g., RO associated with SS / PBCH indicated by SS / PBCH) 4 Asymmetric indicator [00 (Legacy), 01 (Initial), 10 (Non-Initial), 11 (Reserved) 2 (Number of sweeps / repetitions) (a) (RO set) (b) Reserved bits c

[0653] The bit examples of the Asym mTRP indication field can be set as follows: (1) The UE that has received the PDCCH order can transmit a preamble as in the legacy case if the bit of the Asym mTRP indication is '00'. More specifically, if the bit of the Asym mTRP indication is '00', the UE can transmit a preamble at a given frequency location, that is, at a time / frequency location indicated by a given PRACH RO index in the frequency-domain resource assignment information, as in the preamble transmission example of the PDCCH order applied as the baseline. In addition, the preamble can be configured based on the random access preamble index included in the PDCCH order. The direction in which the preamble is transmitted can be transmitted in the direction indicated by the SS / PBCH index included in the PDCCH order.

[0654] (2) If the bit of the asynchronous mTRP indication included in the PDCCH order is '01', the UE may determine that the state is an initial UL-only TRP connection state. Accordingly, the UE may transmit a preamble to the UL-only TRP through a predetermined number of sweeping and / or repeating beams (e.g., corresponding to the Sweeping / repetition number field illustrated in Table 6 or Table 9). The transmission power of the beams through which the preamble is transmitted may be applied as a predetermined or arbitrary transmission power in the initial system connection procedure between the first TRP and the UE.

[0655] The transmission timing of the beams through which the preamble is transmitted may be transmitted in one or more ROs among the PRACH ROs (e.g., the RO configuration field of Table 9) that the first TRP has transmitted to the UE using RRC and / or MAC CE. Here, the RO configuration may not mean a single RO, but a grouping configuration list when multiple ROs are grouped. The number of ROs in the grouping configuration list may correspond to the Sweeping / repetition number field. In addition, the preamble transmitted through the beams may be a preamble generated based on a random access preamble index included in the PDCCH order as shown in Table 9.

[0656] As described above, for the transmitted sweeping and / or repeatedly transmitted preambles, the UE does not set a RAR window timer for RAR reception. In other words, the UE does not receive the RAR and may not perform preamble retransmission.

[0657] (3) If the bit of the asynchronous mTRP indication that has received the PDCCH order is '10', the UE may determine that the system connection state is non-initial. If the system connection state is determined to be non-initial, the UE may transmit a preamble in the direction indicated by the joint TCI state / UL TCI state received via MAC CE or RRC. At this time, the transmission power of the preamble may be calculated using the UL PL calculated by the mathematical expressions 2 and / or 3 described above.

[0658] The frequency location at which the preamble is transmitted can be determined based on frequency domain resource allocation information, and the time resource can be determined by the PRACH RO index field. Additionally, the transmitted preamble can be generated based on the random access preamble index. Therefore, the generated preamble can be transmitted as a UL-only TRP in the time / frequency resources indicated by the PDCCH order in Table 9.

[0659] In order to reduce the number of bits of the DCI format for the PDCCH order exemplified in Table 9 in the sixth detailed embodiment of the eighth embodiment described above, one or more of the sweeping / repetition count field or the RO configuration field may be deleted. If one or more of the sweeping / repetition count field or the RO configuration field is deleted, information to be transmitted to the UE through these fields may be stipulated to be transmitted from the MAC CE and / or RRC.

[0660] In addition, when a new PDCCH order format for the asymmetric mTRP mode is defined separately from the existing and / or baseline PDCCH order format, the fields in the new format may be composed of an indicator field for DCI formats, a frequency-domain resource allocation field, a random access preamble index field, a PRACH RO index field, an asynchronous mTRP indication field (2 bits) (the bit value may be set to, for example, 0 (initial) or 1 (non-initial)), an RO configuration field, a joint TCI status / UL TCI status field, a reserved bits field, etc. Here, bit '0' of the asynchronous mTRP indication field may follow the description of bit '01' of the asynchronous mTRP indication field described in Table 9, and bit '1' of the asynchronous mTRP indication field may follow the description of bit '10' described in Table 8.

[0661] Next, the seventh detailed embodiment of the eighth embodiment is described below.

[0662] As illustrated in FIG. 15 described above, the UE may receive a MAC CE in which the association of joint TCI states / UL TCI states mapped to a PL offset configuration list and / or a delta PL index / value list is updated.

[0663] Hereafter, as shown in Table 9, the first TRP may transmit an Uplink Control Indicator (UCI) for scheduling an uplink SRS signal and / or a PUSCH / PUCCH channel, such as a joint TCI state / UL TCI state as exemplified in FIG. 15 associated with a PL offset and delta PL, to the UE. An example of information included in the UCI format for scheduling an SRS signal and / or a PUSCH / PUCCH channel may be exemplified as shown in Table 10 below.

[0664] Identifier field for DCI formats Frequency-domain resource allocation field Scheduled time / frequency resource allocation field PCI index field Joint TCI status / UL TCI status field… Reserved bits field

[0665] A UE receiving a UCI as illustrated in Table 10 may transmit an SRS / PUSCH / PUCCH in a direction indicated by the Joint TCI Status / UL TCI Status field. In addition, the UE may calculate the transmit power of the SRS / PUSCH / PUCCH using the PL offset configuration list, delta PL index / value received via the MAC CE and / or RRC signaling described above, and the UL PL value calculated using Equation 2 and / or Equation 3 described above. The preamble transmitted by the UE may transmit the SRS / PUSCH / PUCCH at a frequency location set by the frequency domain resource allocation information and at a scheduled time / frequency resource location. The PL offsets, TT offsets, and UL TCI status / space relationship described above and the mapping information between the PL offsets may be transmitted to the UE from the first TRP via RRC signaling or may be transmitted to the UE from the first TRP via a new / existing reused MAC-CE, depending on the mobility of the UE.

[0666] If the UE is moving slowly, the UL TCI status information element (IE) for each UL dedicated TRP in the RRC data of the PDSCH indicated by the DCI through the UE Search Space (USS) of the UE can be transmitted to the UE through RRC signaling.

[0667] On the other hand, when the UE moves quickly, RRC signaling can be used, but in order to reduce latency, PL offsets, TT offsets, and mapping information between UL TCI state / space association and PL offsets can be specified in the MAC-CE field in addition to the RRC data of the PDSCH indicated by the DCI through the UE's USS and transmitted to the UE. In this case, the MAC-CE applied can be reused as defined in the current 5G NR standard, or can be modified / extended as defined in the current 5G NR standard, or can be used as a newly defined MAC CE for "asymmetric mTRP MAC-CE".

[0668] If absolute TAs are used instead of TT offsets, the TAC MAC-CE corresponding to each UL-specific TRP can be reused. However, if the newly defined asymmetric mTRP MAC-CE is used, the newly defined asymmetric mTRP MAC-CE can include the PL offsets, TT offsets (or absolute TAs), and the UL TCI state / space relationship and the mapping information between PL offsets and TT offsets, or any other possible information required.

[0669] The method described above can be used to quickly respond to asymmetric mTRP scenarios, and the number of bits used can be reduced by transmitting TT offsets to the UE rather than transmitting absolute TAs to the UE.

[0670] When the information described above is transmitted to the UE in the form of a UL TCI status IE for each UL-only TRP via RRC signaling, the UL TCI status IE may reflect the PL offsets, TT offsets (or absolute TAs) described above, and mapping information between the UL TCI status / space relationship and PL offsets in the form of elements.

[0671] When transmitting the information described above to the UE in the form of a UL TCI status IE for each UL-only TRP via RRC signaling, the UL TCI status IE may reflect TT offsets (or absolute TAs) among the PL offsets, TT offsets (or absolute TAs) and mapping information between the UL TCI status / space relationship and PL offsets described above, by extending the TAG ID concept previously reflected in the UL TCI status IE.

[0672] In addition to the methods described above, all possible extensions (e.g., increasing the number of TAG IDs beyond the current two and mapping the absolute TA values ​​specified to the TAG IDs) can also be understood by the present disclosure in the same or similar manner. Therefore, methods identical or similar to the methods described in the present disclosure can be included within the scope of the present disclosure.

[0673] Figure 20 is a conceptual diagram for explaining a case in which UL communication is performed between a UE and UL-only TRPs in an asymmetric mTRP environment.

[0674] Referring to FIG. 20, a base station (2041) can communicate with a UE (2011) located within its cell using a plurality of TRPs (2001, 2002, 2003). In the example of FIG. 20, only three TRPs (2001, 2002, 2003) are illustrated for the sake of simplicity of the drawing, but the number of TRPs that can be included within the base station (2041) is not limited to three and may be more or less than three.

[0675] Also, in the embodiment of FIG. 20, it is assumed that three different TRPs are included in one base station (2041). A first TRP (2001) may have a first cell area (1110), a second TRP (2002) may have a second cell area (2020), and a third TRP (2003) may have a third cell area (2030). The first TRP (2001) illustrated in FIG. 20 may be referred to as a macro TRP or head TRP as described above, and may perform downlink (DL) and uplink (UL) transmission with a UE (2011). The second TRP (2002) and the third TRP (2003) may be UL-only TRPs as described above. Therefore, the second TRP (2002) and the third TRP (2003) may be TRPs that do not transmit any signal in the downlink or may be TRPs that transmit only a minimal downlink signal.

[0676] The UE (2011) illustrated in FIG. 20 may be UE #0 described in FIGS. 10A and 10B and may be in an RRC connection state with the first TRP (2001). In other words, the UE (2011) in FIG. 20 may have performed steps S1000, S1021 to S1023 described in FIGS. 10A and 10B with the first TRP (2001). In addition, the UE (2011) in FIG. 20 may have performed steps S1030, S1040, S1051, S1052, and S1060 described in FIGS. 10A and 10B. Specific embodiments or modified embodiments for steps S1030, S1040, S1051, S1052, and S1060 have been described above, so redundant descriptions are omitted.

[0677] FIG. 20 may be a diagram schematically illustrating a case where a UE (2011) performs steps S1071 and S1072 in FIG. 10b. The UE (2011) may perform UL communication with UL-only TRPs (2002, 2003) using PL offsets, TT offsets (or absolute TAs) and UL TCI state / space relationship and mapping information between PL offsets and TT offsets from the first TRP (2001). More specifically, the UE (2011) may perform UL transmission to the second TRP (2002) as indicated by reference numeral 2051. At this time, the UL transmission to the second TRP (2002) may be configured by the first TRP with the beam direction, beam power, and resources (frequency resources and / or time resources) set as described above. In addition, the UE (2011) can perform UL transmission to the third TRP (2003) as indicated by reference numeral 2052. Here, the UL transmission to the third TRP (2003) can be configured by the first TRP with the beam direction, beam power, and resources (frequency resources and / or time resources) set as described above. In Fig. 20, it is assumed that the UL transmission is to two different UL-only TRPs. However, the present disclosure is not limited thereto. For example, the UE (2011) may perform UL transmission to only one UL-only TRP, or may perform UL transmission to three or more UL-only TRPs. In addition, although UL transmission to the first TRP (2001) is not illustrated in Fig. 20, the UE (2011) may also perform UL transmission to the first TRP (2001) if necessary.

[0678] Meanwhile, the PL offset and TA of the UE (2011) may be updated while performing UL communication (2051, 2052). An example of a method for updating the PL offset and TA of the UE (2011) may be performed as follows.

[0679] The UE (2011) can obtain TA value(s) for the UL-only TRP(s) through a single DCI-based two-TA procedure in a state where the UL-only TRP(s) that receive the service, i.e., perform UL transmission, are determined. Thereafter, the UE (2011) can perform beam management (BM) with the UL-only TRP(s) using SRS. As described above, the beam management can be performed in the first TRP (2001) w...

Claims

1. In the method of user equipment (UE), A step of receiving a first message instructing to transmit a first uplink (UL) signal from a first Transmission and Reception Point (TRP) to a first TRP or a second TRP in a connected state with a radio resource control (RRC) connection; generating the first UL signal based on the received first message; and A step of transmitting the generated first UL signal to the second TRP when the received first message instructs transmission to the second TRP; The above second TRP is a TRP controlled by the above first TRP, UE's method.

2. In claim 1, The above first UL signal is a random access (RA) preamble transmitted through a physical random access channel (PRACH). UE's method.

3. In claim 1, The above first message is downlink control information (DCI) used for physical downlink control information (PDCCH)-order, The DCI includes a first field indicating whether a path loss (PL) offset is included and the PL offset included when determining the transmission power of the first UL signal. UE's method.

4. In claim 3, The first field is present when a first parameter included in an RRC message received from the first TRP indicates activation of the first field, and an indicated transmission configuration indication (TCI) state configuring one or more of the PL offsets is configured in the RRC message. UE's method.

5. In claim 3, Wherein the first parameter of the RRC message received from the first TRP before reception of the first message indicates activation of the first field included in the DCI, and the transmission configuration indication (TCI) of the RRC message or the Media Access Control-Control element (MAC CE) message received before reception of the first message from the first TRP indicates one joint / UL TCI state constituting the PL offset, and the first field indicates whether the PL offset of the one joint / UL TCI state is included in the calculation of the transmission power of the first UL signal transmitted to the second TRP. UE's method.

6. In claim 3, Further comprising the step of receiving an RRC message or a Media Access Control-Control element (MAC CE) message from the first TRP before receiving the first message, If the transmission configuration indication (TCI) of the RRC message or the MAC CE message indicates two joint / UL TCI states that constitute the PL offset, the first field indicates that the PL offset configured in one of the two indicated joint / UL TCI states is included in the calculation of the transmission power of the second UL signal transmitted to the second TRP. UE's method.

7. In claim 3, A first parameter of an RRC message received from the first TRP before reception of the first message indicates activation of the first field included in the DCI, and when the RRC message is configured with two indicated joint / UL transmission configuration indication (TCI) states for a serving cell together with the PL offset, the first field indicates transmission of the first UL signal in one of the two joint / UL TCI states. UE's method.

8. In claim 3, If the first field is instructed to apply the PL offset to a transmission configuration indication (TCI) state or UL TCI state specified by a higher layer, the first PL offset to be applied to the first UL signal power calculation is instructed to use the difference between the PL offset and the PL value related to the first UL signal transmission in the active downlink (DL) bandwidth part (BWP) from the first TRP. UE's method.

9. In the method of the first transmission and reception point (TRP), A step of transmitting a first message instructing a user equipment (UE) in a radio resource control (RRC) connected state to transmit a first uplink (UL) signal to one or more second TRPs; A step of receiving first information related to the first message from the one or more second TRPs; and A step of transmitting a second message instructing one or more second TRPs to transmit a second UL signal based on the first information, The above second TRP is a TRP controlled by the above first TRP, Method of the 1st TRP.

10. In claim 9, The above first UL signal is a random access (RA) preamble transmitted through a physical random access channel (PRACH). Method of the 1st TRP.

11. In claim 9, The above first message is downlink control information (DCI) used for physical downlink control information (PDCCH)-order, The DCI includes a first field indicating whether a path loss (PL) offset is included and the PL offset included when determining the transmission power of the first UL signal. Method of the 1st TRP.

12. In claim 11, Further comprising a step of transmitting an RRC message transmitted to the UE before transmitting the first message, Including the first field in the DCI when a first parameter included in the RRC message indicates activation of the first field and a transmission configuration indication (TCI) state configuring one or more PL offsets is configured in the RRC message. Method of the 1st TRP.

13. In claim 11, Further comprising a step of transmitting an RRC message or a Media Access Control-Control element (MAC CE) message to the UE before transmitting the first message, If the transmission configuration indication (TCI) of the RRC message or the MAC CE message indicates two joint / UL TCI states that constitute the PL offset, the first field indicates that the PL offset configured in one of the two indicated joint / UL TCI states is to be included in the calculation of the transmission power of the second UL signal transmitted to the second TRP. Method of the 1st TRP.

14. In claim 11, Further comprising the step of transmitting an RRC message and a Media Access Control-Control element (MAC CE) message to the UE before transmitting the first message, Wherein the first parameter of the RRC message indicates activation of the first field included in the DCI, and the transmission configuration indication (TCI) of a Media Access Control-Control element (MAC CE) message received before receiving the first message from the RRC message or the first TRP indicates one joint / UL TCI state constituting the PL offset, and the first field indicates whether the PL offset of the one joint / UL TCI state is included in the calculation of the transmission power of the first UL signal transmitted to the second TRP. Method of the 1st TRP.

15. In claim 11, Further comprising the step of transmitting an RRC message to the UE before transmitting the first message, Wherein the first parameter of the RRC message indicates activation of the first field included in the DCI, and when the RRC message is configured with two indicated joint / UL transmission configuration indication (TCI) states for the serving cell together with the PL offset, the first field indicates transmission of the first UL signal in one of the two joint / UL TCI states. Method of the 1st TRP.

16. In claim 11, If the first field is instructed to apply the PL offset to a transmission configuration indication (TCI) state or UL TCI state specified by a higher layer, the first PL offset to be applied to the first UL signal power calculation is instructed to use the difference between the PL offset and the PL value related to the first UL signal transmission in the active downlink (DL) bandwidth part (BWP) from the first TRP. Method of the 1st TRP.

17. In user equipment (UE), At least one processor, wherein said at least one processor comprises: Receive a first message instructing to transmit a first uplink (UL) signal from a first Transmission and Reception Point (TRP) to a first TRP or a second TRP in a connected state with a radio resource control (RRC); generating the first UL signal based on the received first message; and If the received first message instructs transmission to the second TRP, causing the generated first UL signal to be transmitted to the second TRP, The above second TRP is a TRP controlled by the above first TRP, UE.

18. In claim 17, The above first UL signal is a random access (RA) preamble transmitted through a physical random access channel (PRACH). UE.

19. In claim 17, The above first message is downlink control information (DCI) used for physical downlink control information (PDCCH)-order, The DCI includes a first field indicating whether a path loss (PL) offset is included and the PL offset included when determining the transmission power of the first UL signal. UE.

20. In claim 19, The first field is present when a first parameter included in an RRC message received from the first TRP indicates activation of the first field, and an indicated transmission configuration indication (TCI) state configuring one or more of the PL offsets is configured in the RRC message. UE.

Images