Method and apparatus for supporting multi-transceiving-point operation in wireless communication system

Abstract

The present disclosure relates to a method and an apparatus for supporting multiple transmit-receive point (TRP) operation in a wireless communication system. According to an embodiment of the present disclosure, a method in which a user equipment supports a multi-TRP operation in a wireless communication system comprises the steps of: receiving a first synchronization signal block (SSB) from a first TRP that is a serving TRP of the user equipment; receiving a second SSB from a second TRP which is a neighbor TRP of the first TRP; identifying a receive time difference (RTD) between the first SSB and the second SSB; and if a measurement report event is triggered, transmitting a measurement report message including information indicating the RTD to the first TRP.

Description

Technical Field

[0001] The present disclosure relates to methods and apparatus related to multi-TRP operations in wireless communication systems. Background Art

[0002] 5G mobile communication technology defines a wide frequency band, making it possible to realize high transmission rates and new services, not only in the "below 6 GHz" frequency band such as 3.5 GHz, but also in the "above 6 GHz" frequency band called millimeter wave including 28 GHz and 39 GHz. In addition, in order to achieve a transmission rate 50 times faster than that of 5G mobile communication technology and an ultra-low latency that is only one-tenth of that of 5G mobile communication technology, the realization of 6G mobile communication technology in the terahertz frequency band (for example, the 95 GHz to 3 THz frequency band) (called "super 5G system") has been considered.

[0003] In the early stages of 5G mobile communications technology development, in order to support related services and meet performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC), continuous standardization work has been carried out on the following aspects: beamforming and massive MIMO for mitigating radio wave path loss in mmWave and increasing radio wave transmission distance; dynamic operation that supports multiple parameter sets (e.g., operating multiple subcarrier spacings) to efficiently utilize mmWave resources and time slot formats; initial access technology that supports multi-beam transmission and broadband; definition and operation of BWP (bandwidth part); new channel coding methods such as LDPC (low-density parity check) codes for large amounts of data transmission and polar codes for high-reliability transmission of control information; L2 preprocessing; and network slicing that provides dedicated networks for specific services.

[0004] Currently, discussions are underway to improve and enhance the initial version of 5G mobile communication technology in view of the services it is to support. In addition, in terms of physical layer standardization, work has been carried out on the following technologies: V2X (vehicle-to-everything), which aims to assist autonomous vehicles in making driving decisions and improve user convenience based on the location and status information sent by the vehicle; NR-U (New Radio-Unlicensed Band) technology, which aims to achieve system operation that complies with various regulatory requirements in the unlicensed band; NR UE energy saving; Non-terrestrial Network (NTN) technology, in which the UE communicates directly with satellites to provide coverage in areas where communication with terrestrial networks is not possible; and positioning technology.

[0005] In addition, in terms of air interface architecture / protocol, standardization work on the following technologies is also continuing: Industrial Internet of Things (IIoT) technology, which supports new services through interoperability and integration with other industries; Integrated Access and Backhaul (IAB) technology, which provides nodes for network service area expansion by supporting wireless backhaul links and access links in an integrated manner; Mobility enhancement technologies including conditional switching and DAPS (dual active protocol stack) switching; and two-step random access (NR two-step RACH) technology for simplifying the random access process. In terms of system architecture / services, there are also related standardization work: 5G baseline architecture (e.g., service-based architecture or service-based interface) for combining network function virtualization (NFV) and software defined network (SDN) technologies, and mobile edge computing (MEC) for receiving services based on UE location.

[0006] As 5G mobile communication systems are commercialized, an exponentially growing number of connected devices will be connected to the communication network, so it is expected that the enhanced functions and performance of 5G mobile communication systems and the integrated operation of connected devices will become indispensable. To this end, new research is planned related to: extended reality (XR) to effectively support AR (augmented reality), VR (virtual reality), MR (mixed reality), etc.; 5G performance improvement and complexity reduction by utilizing artificial intelligence (AI) and machine learning (ML); AI service support; Metaverse service support; and drone communication.

[0007] Furthermore, this development of 5G mobile communication systems will lay the foundation for the development of new waveforms for providing terahertz band coverage for 6G mobile communication technology, multi-antenna transmission technologies such as full-dimensional MIMO (FD-MIMO), array antennas and massive antennas, metamaterial-based lenses and antennas for improving terahertz band signal coverage, high-dimensional spatial multiplexing technology using OAM (orbital angular momentum), and RIS (reconfigurable smart surface), as well as full-duplex technology for improving the frequency efficiency of 6G mobile communication technology and improving system networks; AI-based communication technology that utilizes satellites and AI (artificial intelligence) from the design stage and builds in end-to-end AI support functions to achieve system optimization; and next-generation distributed computing technology that implements services whose complexity exceeds the limits of UE operating capabilities by utilizing ultra-high-performance communication and computing resources. Summary of the invention

[0008] Technical issues

[0009] The present disclosure provides a method and apparatus for efficiently supporting multi-TRP operations in a wireless communication system.

[0010] The present disclosure also provides a method and apparatus for supporting multi-TRP operation based on a UE's received time difference (RTD) measurement report in a wireless communication system.

[0011] The present disclosure also provides a method and apparatus for supporting multi-TRP operation based on RTD measurement report of a base station (TRP) in a wireless communication system.

[0012] Technical Solution

[0013] According to an embodiment of the present disclosure, a method for supporting multi-TRP operation by a UE in a wireless communication system includes: receiving a first synchronization signal block (SSB) from a first TRP which is a service TRP of the UE; receiving a second SSB from a second TRP which is a neighbor TRP of the first TRP; identifying a reception time difference (RTD) between the first SSB and the second SSB; and when a measurement report event is triggered, sending a measurement report message including information indicating the RTD to the first TRP.

[0014] The method may also include: in response to satisfying the RTD limit, receiving a radio resource control (RRC) reconfiguration message from the first TRP to add the second TRP for the multi-TRP operation.

[0015] In the method, if the RTD is less than a threshold, the RTD limit is satisfied, and if the RTD is greater than the threshold, the second TRP is not added.

[0016] In the method, at least one of a transmission period and an SSB index of the first SSB and the second SSB is the same.

[0017] In the method, the information indicating the RTD includes at least one of the following: the RTD corresponding to the SSB index with the maximum received signal strength, the average RTD for multiple SSB indexes, and the RTD for a defined number of SSB indexes selected based on signal strength or signal quality.

[0018] In addition, according to an embodiment of the present disclosure, a UE in a wireless communication system includes a transceiver and a processor, and the processor is configured to: receive a first SSB from a first TRP that is a service TRP of the UE through the transceiver; receive a second SSB from a second TRP that is a neighbor TRP of the first TRP through the transceiver; identify a reception time difference (RTD) between the first SSB and the second SSB; and when a measurement report event is triggered, send a measurement report message containing information indicating the RTD to the first TRP through the transceiver.

[0019] In addition, according to an embodiment of the present disclosure, a method for supporting multi-TRP operation by a service TRP of a UE in a wireless communication system includes: sending a transmission delay measurement request message to a neighbor TRP of the service TRP, the transmission delay measurement request message including information about a dedicated preamble code available for measuring the transmission delay in a path between the UE and the neighbor TRP; allocating the dedicated preamble code to the UE; receiving a report message of a transmission delay measurement result including a physical random access channel PRACH preamble code from the neighbor TRP, the neighbor TRP receiving the PRACH preamble code from the UE; and determining whether to perform multi-TRP operation on the UE based on the received transmission delay measurement result.

[0020] In the method, the determination includes: identifying a first transmission delay in a path from the UE to the service TRP; identifying a second transmission delay in a path from the UE to the neighbor TRP based on the received transmission delay measurement result; and identifying a receive time difference (RTD) between the first transmission delay and the second transmission delay.

[0021] The method also includes: when the RTD is less than a threshold, determining that the RTD is valid, and sending a radio resource control RRC reconfiguration message to the UE to add the neighbor TRP for the multi-TRP operation.

[0022] The method further includes: determining that the RTD is invalid when the RTD is greater than the threshold, and determining not to perform a multi-TRP operation on the UE.

[0023] In the method, the dedicated preamble code is used for transmission delay measurement associated with the configuration of the multi-TRP operation.

[0024] In addition, according to an embodiment of the present disclosure, a service TRP in a wireless communication system includes a transceiver, a communication interface and a processor, and the processor is configured to: send a transmission delay measurement request message to a neighbor TRP of the service TRP through the communication interface, and the transmission delay measurement request message includes relevant information about a dedicated preamble code that can be used to measure the transmission delay in the path between the UE and the neighbor TRP; allocate the dedicated preamble code to the UE through the transceiver; receive a report message including a transmission delay measurement result of a physical random access channel (PRACH) preamble code from a neighbor TRP that receives the PRACH preamble code from the UE through the communication interface; and determine whether to perform a multi-TRP operation on the UE based on the received transmission delay measurement result. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1An example of a wireless communication system applying multi-TRP operation according to an embodiment of the present disclosure is shown; Figure 2A and Figure 2B An example of a receive time difference (RTD) for determining whether a multi-TRP operation is valid according to an embodiment of the present disclosure is shown; Figure 3 A flowchart of a method for supporting multiple TRP operations based on an RTD measurement report of a UE in a wireless communication system according to an embodiment of the present disclosure is shown; Figure 4 Shown in Figure 3 A method executed in a UE in an embodiment; Figure 5 Shown in Figure 3 The method performed in the first TRP (the service TRP) of the embodiment; Figure 6 A flowchart showing a method for supporting multiple TRP operations based on an RTD measurement report of a base station (TRP) in a wireless communication system according to an embodiment of the present disclosure is shown; Figure 7 Shown in Figure 6 A method executed in a UE in an embodiment; Figure 8 Shown in Figure 6 The method performed in the first TRP (the service TRP) of the embodiment; Fig. 9 Shown in Figure 6 The method performed in the second TRP (neighbor TRP) of the embodiment; Fig.10 An example of a configuration of a UE in a wireless communication system according to an embodiment of the present disclosure is shown; and Fig.11 An example of the configuration of a base station (TRP) in a wireless communication system according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0026] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. When it is determined that a detailed description of a known technology or function will make the subject of the present invention unclear, the detailed description of the known technology or function may be omitted. The terms used herein are defined according to the functions in the present disclosure and may be replaced with other terms according to the intention or convention of the user or operator. Therefore, these terms should be defined based on the entire disclosure.

[0027] The effects, features and methods for achieving these effects and features of the present disclosure can be understood by the following embodiments described in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed herein, and various changes may be made thereto. The embodiments disclosed herein are only used to inform those of ordinary skill in the art of the scope of the present disclosure. The present invention is defined only by the appended claims. Throughout the specification, the same reference numerals represent the same elements.

[0028] It will be understood that each block in each flowchart and combinations of the flowcharts can be executed by computer program instructions.

[0029] In addition, each frame can represent code module, code segment or partial code, and code comprises one or more executable instructions for performing specific logic function.In addition, it should also be noted that in some alternative embodiments, the function mentioned in the frame can occur in different orders.For example, two frames of continuous display can be basically executed simultaneously or in reverse order according to corresponding function.

[0030] As used herein, the term "unit" refers to a software element or a hardware element such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). The unit plays a certain role. However, the "unit" is not limited to software or hardware. The "unit" can be configured in an addressable storage medium, or can be configured to execute one or more processors. Therefore, as an example, the "unit" includes elements such as software elements, object-oriented software elements, class elements and task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data architectures, tables, arrays, and variables. The functions provided within the components and "units" can be merged into a smaller number of components and "units", or further separated into other components and "units". In addition, the components and "units" can be implemented as executing one or more central processing units (CPUs) in a device or a secure multimedia card. According to an embodiment, the "unit" may include one or more processors.

[0031] As used herein, each of phrases such as “A or B,” “at least one of A and B,” “at least one of A or B,” “A, B or C,” “at least one of A, B and C,” and “at least one of A, B or C” may include all possible combinations of items listed together in the corresponding phrase. As used herein, terms such as “1st” and “2nd,” or “first” and “second,” may be used to simply distinguish a corresponding component from other components, and do not limit the components in other aspects (e.g., importance or order).

[0032] As used herein, the terms used to identify access nodes, the terms used to represent network entities, the terms used to represent messages, the terms used to represent interfaces between network entities, and the terms used to represent various identification information are examples provided for ease of description. Therefore, the present disclosure is not limited to these terms, and these terms can be replaced with other terms representing objects with equivalent technical concepts.

[0033] In the present disclosure, for convenience, terms and names defined in the 3rd Generation Partnership Project and 5G and NR standards are used. In the embodiments of the present disclosure, for convenience, a 5G system is described as an example, but the embodiments of the present disclosure are not limited to the terms and names in the 5G system, and can also be applied to wireless communication systems according to other standards.

[0034] In the present disclosure, a base station (BS) is a network entity that allocates resources to a UE and can communicate with the UE, and may be at least one of an eNode B, a Node B, a gNB, a radio access network (RAN), an access network (AN), a RAN node, an integrated access / backhaul (IAB) node, a radio access unit, a base station controller, a node on a network, or a transceiver point (TRP). A user equipment (UE) may be at least one of a terminal, a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function.

[0035] Unlike traditional systems, 5G systems can support services that require high transmission rates, services with extremely short transmission delays, and services that require high connection density. In a wireless communication network using multiple base stations, multiple cells, multiple TRPs, or multiple beams, cooperative communication (cooperative transmission) between base stations, cells, TRPs, and / or beams can increase the strength of the signal received by the UE and effectively perform interference control between base stations, cells, TRPs, and / or beams, thereby meeting various service requirements. For example, joint transmission (JT) using multiple TRPs is a representative transmission technology for cooperative communication, which sends signals to the UE through multiple TRPs, thereby increasing the strength or throughput of the signal received by the UE.

[0036] In addition, in the 5G system, a synchronization signal block (SSB) is a physical layer signal block including a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The base station can send one or more synchronization signal blocks (SSBs) within 5 milliseconds, and each SSB sent from the base station can be identified by an SSB index. The UE can detect the PSS and SSS in the initial access phase and decode the PBCH. The UE can obtain a master information block (MIB) from the PBCH, and can configure a control resource set (CORESET) #0 (which can correspond to a control resource set with a control resource set index of 0) through the MIB. In addition, assuming that the selected SSB and the demodulation reference signal (DMRS) sent in the control resource set #0 are quasi-co-located (QCLed), the UE can monitor the control resource set #0. The UE can use the received system information sent in the control resource set #0 as downlink control information. The UE can obtain configuration information related to the random access channel (RACH) required for initial access from the received system information. The UE may send a physical RACH (PRACH) to the base station in view of the selected SSB index, and the base station receiving the PRACH may obtain information of the SSB index selected by the UE. The base station may know which SSB the UE has selected from the SSBs and monitor the control resource set #0 associated therewith.

[0037] In addition, in the 5G system, beam management refers to communication by selecting the optimal transmit / receive beam pair of the transmit beam on the transmitting side and the receive beam on the receiving side. During the initial cell search process, the UE can receive the SSB sent from the base station. During this process, the base station can use multiple different transmit beams to send multiple SSBs in sequence, and the UE can form multiple receive beams in sequence to measure the received signal strength of each of the multiple SSBs and find the optimal receive beam. The receive beam found in this way and the transmit beam that sends the corresponding SSB become the initial transmit / receive beam pair. If the initial transmit / receive beam pair is selected, the optimal transmit / receive beam pair can be determined by using the beam adjustment process of the CSI-RS.

[0038] In the present disclosure, an SSB may be transmitted through a base station (e.g., a TRP), and SSBs having the same or different SSB indices may be transmitted through multiple TRPs. In this case, when receiving an SSB from a TRP, the UE may measure / identify the reception time of each SSB and transmit information related to the reception time measured for each SSB to the TRP serving the UE.

[0039] In addition, in the present disclosure, the TRP may provide high-layer signaling information (or configuration information) to the UE, and the high-layer signaling may be signaling corresponding to at least one of the following signalings, or may be signaling corresponding to a combination of one or more of the following signalings.

[0040] Master Information Block (MIB)

[0041] System Information Block (SIB) or SIB X (X=1,2…)

[0042] Radio Resource Control (RRC)

[0043] Media Access Control (MAC) Control Element (CE)

[0044] In addition, in the present disclosure, the TRP may provide L1 signaling information to the UE, and the L1 signaling information may be signaling corresponding to at least one of the signaling methods using the following physical layer channels or signaling, or may be signaling corresponding to a combination of one or more signaling methods using the following physical layer channels or signaling.

[0045] Physical Downlink Control Channel (PDCCH)

[0046] Downlink Control Information (DCI)

[0047] UE-specific DCI

[0048] Group Common DCI

[0049] Public DCI

[0050] Figure 1 An example of a wireless communication system applying multi-TRP operation according to an embodiment of the present disclosure is shown. Figure 2A and Figure 2B An example of a receive time difference (RTD) for determining whether a multi-TRP operation is possible according to an embodiment of the present disclosure is shown. Figure 2A and Figure 2B ,right Figure 1 .

[0051] Figure 1 An example of a network environment in which multiple TRPs (TRP A, TRP B, TRP C) 110a, 110b, and 110c and multiple UEs (UE1, UE2, UE3) 120a, 120b, and 120c exist is shown. At least two or more of the multiple TRPs (TRP A, TRP B, TRP C) 110a, 110b, and 110c can transmit and receive signals with at least one of the multiple UEs (UE1, UE2, UE3) 120a, 120b, and 120c through multi-TRP operation.

[0052] Multiple TRPs (TRP A, TRP B, TRP C) 110a, 110b, and 110c may be connected to the same base station (e.g., one gNB) or different base stations (e.g., multiple gNBs). For example, TRP A and TRP B may be connected to the same base station, while TRP C may be connected to a different base station.

[0053] Multi-TRP operation includes multiple TRPs sending signals to or receiving signals from the UE through collaborative communication, and one example is joint transmission (JT) through multiple TRPs. Multi-TRP operation can be performed if the receive time difference (RTD) indicating the difference in transmission delays between multiple TRPs and the UE is within a threshold range. The threshold can use, for example, the cyclic prefix (CP) length of the orthogonal frequency division multiplexing (OFDM) symbol. The CP length is an example of a threshold, and the threshold can be pre-provided to the UE by the serving TRP through configuration information, or a value pre-agreed between the UE and the serving TRP can be used. In the present disclosure, the serving TRP and the neighbor TRP can be a serving base station and a neighbor base station, or a TRP connected to the same gNB, or a TRP connected to different gNBs.

[0054] exist Figure 1 In the example of FIG. 1 , the downlink (DL) transmission delay (Tprop) between TRP A 110a and UE (UE1) 120a is indicated. A,1 ) 101 and the DL transmission delay (Tprop B 110b) between the UE (UE1) 120a B,1 ) 102 The difference between the first RTD can be measured as △Tprop UE1 =|Tprop A,1 -Tprop B,1 If the first RTD is significantly smaller than the CP length in the OFDM symbol (ie, if the RTD between multiple TRPs is much smaller than the CP length), a multi-TRP operation in which TRP A 110a and TRP B 110b cooperate to transmit a DL signal to UE (UE1) 120a may be stably performed.

[0055] exist Figure 1 In the example of FIG. 1 , the DL transmission delay (Tprop) between TRP A 110a and UE (UE2) 120b is indicated. A,2 ) 101 and the DL transmission delay (Tprop B 110b) between the TRP B 110b and the UE (UE2) 120b B,2 ) The difference between the second RTD of 102 can be measured as △Tprop UE2 =|Tprop A,2 -TpropB,2 If the second RTD is within the CP length range in the OFDM symbol (ie, if the RTD between the multiple TRPs is less than the CP length), a multi-TRP operation may be performed in which TRP A 110a and TRP B 110b cooperate to transmit a DL signal to UE (UE2) 120a.

[0056] exist Figure 1 In the example of FIG. 1 , the DL transmission delay (Tprop) between TRP A 110a and UE (UE3) 120c is indicated. A,3 ) 105 and the DL transmission delay (Tprop) between TRP C 110b and UE (UE3) 120c C,3 ) The difference between the third RTD of 106 can be measured as △Tprop UE3 =|Tprop A,3 -Tprop C,3 |. If the third RTD is greater than the CP length in the OFDM symbol (ie, if the RTD between the multiple TRPs is greater than the CP length), a multi-TRP operation in which TRP A 110a and TRP C 110c cooperate to transmit a DL signal to UE (UE3) 120c may be stably performed. In this case, referring to Figure 2A and Figure 2B , Figure 2A 1 shows a situation where the receiving window (Rx window) 201 of the UE (UE3) 120c starts from the end of the CP. Figure 2B The case where the reception window (Rx window) 211 of the UE (UE3) 120c starts from the beginning of the CP is shown. The OFDM symbol transmitted from the TRP C 110b can be stably received in the reception window (Rx window) 201 of the UE (UE3) 120c, but since the third RTD exceeds the CP length (203, 213), the OFDM symbol transmitted from the TRP A 110a may not be stably received in the reception windows (Rx windows) 201 and 211 of the UE (UE3) 120c.

[0057] In the present disclosure, the UE can measure / identify the RTD between multiple TRPs before performing multi-TRP operations, and send the RTD information to the serving TRP among the multiple TRPs. Based on the received RTD information, the serving TRP determines the RTD between multiple TRPs that is greater than the CP length as an invalid RTD, and prevents the multi-TRP operation from being performed on the UE; if the RTD between multiple TRPs is less than the CP length, the RTD is determined as a valid RTD to allow the multi-TRP operation to be performed on the UE. According to the present disclosure, in situations where a larger RTD may occur (for example, the DL signal received from one TRP is line-of-sight (LOS) reception, while the DL signal received from another TRP is non-LOS reception, a multi-TRP scenario between a macro cell and a small cell, or a multi-TRP scenario where the UE moves at high speed), it can be efficiently determined whether multi-TRP operation is possible before performing multi-TRP operation.

[0058] Figure 3 A flowchart of a method for supporting multiple TRP operations based on the RTD measurement report of the UE in a wireless communication system according to an embodiment of the present disclosure is shown.

[0059] exist Figure 3 In the example of , the multi-TRP operation includes the UE receiving downlink (DL) signals from two or more TRPs. A UE-based RTD measurement and reporting method is proposed, wherein, before performing the multi-TRP operation, the UE 320 measures / identifies the RTD between the multiple TRPs and reports it to the first TRP 310a as the serving TRP, the first TRP 310a determines whether to perform (whether to set) the multi-TRP operation based on the measured / identified RTD information, and if it is determined to perform the multi-TRP operation, the first TRP 310a and the second TRP 310b as a neighbor base station collaborate to perform the multi-TRP operation on the DL.

[0060] Specifically, in Figure 3 In step 301, UE 320 receives an RRC reconfiguration message for measurement reporting related to multi-TRP operation from the first TRP 310a.

[0061] In step 302, UE 320 receives a first SSB from a first TRP 310a, in which case UE 320 may measure / identify a reception time of the first SSB.

[0062] In step 303, UE 320 receives a second SSB from the second TRP 310b, in which case UE 320 can measure / identify the reception time of the second SSB.

[0063] In step 304, when a measurement report (MR) event is triggered, the UE 320 measures / identifies the RTD between the first TRP 310a and the second TRP 310b. In addition, if the measurement report (MR) event is triggered in step 304, the UE 320 may measure a reference signal received power (RSRP), a reference signal received quality (RSRQ), or a signal to interference and noise ratio (SINR) of the first SSB and the second SSB.

[0064] exist Figure 3 In an embodiment, RTD(i) representing the RTD between the first TRP 310a as a service TRP and the second TRP 310b as a neighbor TRP may be defined as in Formula 1 below.

[0065] [Formula 1]

[0066] T RTD (i) = |T SSB,S (i) - T SSB,N (i)|

[0067] T SSB,S (i) : Reception time of the i-th SSB serving TRP

[0068] T SSB,N (i) : Reception time of the i-th SSB of the neighbor TRP

[0069] In Formula 1, T SSB,S (i) is the reception time of the first SSB corresponding to the i-th SSB index received from the first TRP 310a, T SSB,N (i) is the reception time of the second SSB corresponding to the i-th SSB index received from the second TRP 310b. In the example of Formula 1 above, the definition of RTD assumes that the SSB transmission period of the first TRP 310a and the second TRP 310b is the same, the physical cell identifier (PCI) is different, and there are overlapping SSB indexes.

[0070] In addition, regarding the above-mentioned RTD measurement standard, the UE 320 may measure a reception time of receiving a synchronization signal (PSS / SSS) from each of the first TRP 310a and the second TRP 310b, and measure an RTD indicating a difference between these reception times.

[0071] If the SSB burst mapping (=sb-PositionsInBurst IE) or SSB period of the first TRP 310a and the second TRP 310b do not match, at least one SSB having an SSB index at the same position may be transmitted from the first TRP 310a and the second TRP 310b, respectively.

[0072] The ssb-PositionsInBurst IE indicates the time domain position of the SSB transmitted in a half-frame with SS / PBCH blocks (i.e., SSBs), as disclosed in TS 38.331. In the ssb-PositionsInBurst IE, the first / leftmost bit corresponds to SSB index 0 and the second bit corresponds to SSB index 1. In addition, in the ssb-PositionsInBurst IE, a value of 0 on the bitmap indicates that the SSB is not transmitted and a value of 1 indicates that the SSB is transmitted.

[0073] As another example, when the condition in Formula 1 is not satisfied or the SSB periods are different, the UE 320 may measure / identify the RTD through a modulo operation / shift operation.

[0074] For example, if the SSB periods (=ssb-periodicityServingCell IE) of the first TRP 310a and the second TRP 310b match, but there are no overlapping SSB indexes in the SSB burst mapping (=ssb-PositionsInBurst IE), referring to the cell search in Section 4.1 of TS 38.213, the SSB position and SSB index mapping method according to the subcarrier spacing length is shown in Table 1 below. Based on the method shown in Table 1 below, the UE 320 can know the time difference between the SSB indexes in the SSB burst transmitted in the same SSB period (which can be defined as T in Formula 2 below). shift ). For example, case C: it can be identified that when SCS=30kHz and FR1 (3.5GHz) is adopted, SSB index 0 and SSB index 1 differ by 6 symbols, and SSB index 0 and SSB index 2 differ by 14 symbols. Therefore, when there is no overlapping SSB index in the SSB burst mapping (=ssb-PositionsInBurst IE), even if the first TRP 310a and the second TRP 310b send SSBs with different SSB indexes, the UE 320 can measure / identify the RTD based on the time difference between the SSB indexes.

[0075] [Table 1]

[0076] For example, when there is no overlapping SSB index (ie, when the first TRP 310a and the second TRP 310b transmit SSBs having different SSB indexes), T represents the RTD between the first TRP 310a as the serving TRP and the second TRP 310b as the neighbor TRP. RTD (i, j) can be defined according to the following formula 2.

[0077] [Formula 2]

[0078] T RTD (i, j) = |T SSB,S (i) - T SSB,N (j)| + T shift

[0079] T SSB,S (i) : Reception time of the i-th SSB serving TRP

[0080] T SSB,N (j): The reception time of the jth SSB of the neighbor TRP

[0081] T shift : The time difference between the i-th SSB and the j-th SSB

[0082] In Formula 1, T SSB,S (i) is the reception time of the first SSB corresponding to the i-th SSB index received from the first TRP 310a, T SSB,N (j) is the reception time of the second SSB corresponding to the j-th SSB index received from the second TRP 310b. shift is the time difference between the i-th and j-th SSB indexes (i.e., the time difference is expressed as the number of symbols between the starting symbol (first symbol) of the i-th SSB index and the starting symbol (first symbol) of the j-th SSB index).

[0083] In addition, when the SSB periods (=ssb-periodicityServingCell IE) of the first TRP 310a and the second TRP 310b do not match and there are no overlapping SSB indexes in the SSB burst map (=ssb-PositionsInBurst IE), although the SSB periods are different, the candidate setting values ​​of the configurable SSB periods are set in the form of multiples, so that there should be overlapping parts between them. Therefore, even in this case, the UE 320 can measure / identify the RTD by using the modulus operation of the multiple relationship (for example, when the SSB periods of the first TRP 310a and the second TRP 310b are the least common multiple). In TS 38.331, the candidate setting values ​​of the SSB period are shown in the form of multiples, such as ssb-periodicityServingCell ENUMERATED {ms5, ms10, ms20, ms40, ms80, ms160, spare2, spare1}.

[0084] Continue to refer Figure 3In step 305, UE 320 sends a measurement report message to the first TRP 310a, which includes RTD information indicating the RTD measured / identified in step 304.

[0085] In step 306, the first TRP 310a that receives the RTD information determines / identifies whether the RTD associated with the UE 320 satisfies the RTD limit. Specifically, the TRP 310a determines whether the RTD associated with the UE 320 is within (less than) a threshold value (eg, CP length) based on the RTD information.

[0086] In step 307, when the RTD associated with the UE 320 is less than the threshold, the TRP 310a determines / recognizes that the RTD is valid and sends an RRC reconfiguration message for multiple TRPs (ie, for adding the second TRP 310b) to the UE 320.

[0087] In step 308, when the RTD associated with the UE 320 is greater than the threshold, the first TRP 310a determines / recognizes that the RTD is invalid and does not configure multiple TRPs for the UE 320 (ie, in this case, the second TRP 310b is not added).

[0088] Therefore, according to the above Figure 3 In an embodiment, the UE measures / identifies the RTD between multiple TRPs before performing the multi-TRP operation, and when the RTD is greater than a predetermined threshold (e.g., CP length), the serving TRP may prevent the multi-TRP operation from being performed to prevent DL performance degradation. When the RTD is less than the predetermined threshold (e.g., CP length), the serving TRP may cooperate with the neighbor TRP to stably perform the multi-TRP operation of sending DL signals to the UE.

[0089] Meanwhile, in the present disclosure, the RTD information can be expressed as T in Formula 1. RTD (i) Value or T in Formula 2 RTD (i, j) values ​​are sent, or they can be configured / sent as follows.

[0090] For example, the RTD information may be composed of multiple bits or 1-bit information, as shown in the following methods 1-1) and 1-2).

[0091] 1-1) Multiple bits: A method of configuring RTD information using several bits, where the several bits represent the mapping index of each RTD range (e.g., the timing advance in TS 38.211)

[0092] 1-2) 1 bit: A method for a UE to configure 1-bit RTD information indicating whether multiple TRPs are possible (yes or no) after measuring RTD, considering the SCS and CP type (normal or extended)

[0093] In addition, as an example, the RTD information may be transmitted per SSB, as shown in the following methods 2-1) to 2-3) (see the example in Table 2 below).

[0094] 2-1) A method for sending an RTD corresponding to the best SSB index (strongest received signal) for the cell result included in the measurement report message in step 305 above

[0095] 2-2) A method of taking the average RTD of multiple SSB indexes and sending the average RTD of the cell results in the measurement report message in step 305

[0096] 2-3) Method for sending RTD of N best SSB indexes selected based on RSRP / RSRQ / SINR

[0097] [Table 2]

[0098] In addition, for example, the RTD information can be transmitted through the signaling / methods shown in the following 3-1) to 3-3).

[0099] 3-1) A method for sending RTD information by adding a new field in a traditional measurement report message, and a method for including configuration parameters for on / off settings of corresponding multi-TRP operations, wherein the measurement report (MR) trigger condition can use the A1 / A2 / … event conditions of the traditional method.

[0100] 3-2) A method of transmitting RTD information through uplink control information (UCI), or a method of transmitting RTD information via an uplink MAC control element (UL MAC CE) by setting a target TRP for RTD measurement.

[0101] 3-3) A method of sending RTD information by sending msg3 to the base station through the UE during the random access process.

[0102] Meanwhile, in the present disclosure, a target TRP (eg, the second TRP 310 b ) that is a target of RTD measurement may be recognized / identified by the following methods 4-1) and 4-2).

[0103] 4-1) A method for identifying a target TRP based on PCI when the PCI of the target TRP is different from the PCI of the serving TRP (this is similar to the PCI-based measurement report target).

[0104] 4-2) When the target TRP and the service TRP have the same PCI, 4-2-1) A method of identifying by assigning different SSB indices to the target TRP and the service TRP, wherein the SSB indices used by each TRP are assigned so as not to overlap. For example, in frequency band 1 (FR1) of the NR standard, a maximum of eight SSBs (index = 0, ..., 7) can be assigned, and the service TRP uses index = 0, ..., 3, and the target TRP uses index = 4, ..., 7.

[0105] 4-2-2) When the SSB indices assigned to the target TRP and the service TRP overlap, for example in FR1, a maximum of eight SSBs can be allocated (index = 0,…,7). If the service TRP uses index = 0,…,3 and the target TRP also uses index = 0,…,3, a method for identifying the TRP is required and the following methods 4-2-2-1) and 4-2-2-2) can be supported.

[0106] 4-2-2-1) A method of including information (e.g., index) for identifying a TRP in the MIB (through the PBCH), wherein the number of bits may be determined based on the number of TRPs that can be connected to a base station with the same PCI. When this method is used, when generating a PSS / SSS sequence in an SSB, a sequence is generated based on the information (e.g., index).

[0107] 4-2-2-2) A method for identifying TRP by making the resource position of SSB in the frequency domain / time domain different. Here, in the frequency domain, the absoluteFrequencySSB IE in the RRC information as shown in Table 3 below is used to set the position of SSB differently; in the time domain, the ssb-periodicityServingCell IE in the RRC information (i.e., ssb-periodicityServingCell ENUMERATED {ms5, ms10, ms20, ms40, ms80, ms160, spare2, spare1} in the RRC information) is used to set the position of SSB differently.

[0108] [Table 3]

[0109] Figure 4 Shown in Figure 3 The method is performed in the UE in the embodiment.

[0110] exist Figure 4 In step 401, the UE 320 receives an RRC reconfiguration message for measurement reporting related to multi-TRP operation from the first TRP 310a.

[0111] In step 402, the UE 320 receives a first SSB from the first TRP 310a, and in step 403, the UE 320 receives a second SSB from the second TRP 310b. As described above, the first SSB and the second SSB may have the same SSB index or different SSB indexes. In addition, the first SSB and the second SSB may be received in the same SSB period or in different SSB periods. In addition, the UE 320 may receive the first SSB and the second SSB based on signaling information (RRC information, SIB, MAC CE, L1 signaling information, etc.) received from the first TRP 310a or the second TRP 310b, and may distinguish / identify the second TRP 310b as a target TRP related to multi-TRP operation.

[0112] When a measurement report (MR) event is triggered in step 404, UE 320 may measure / identify RTD based on the reception time of the first SSB and the second SSB. RTD may be measured / identified using Formula 1 as described above, and RTD information indicating RTD may be configured and transmitted using the various methods described above.

[0113] In step 405, the UE 320 sends a measurement report message including the RTD information to the first TRP 310a. In step 406, the UE 320 receives an RRC reconfiguration message for multiple TRPs (i.e., for adding the second TRP 310b) from the first TRP 310a as a response that the RTD limit is met. The response that meets the RTD limit refers to a response in the UE 320 in which the RTD is within a threshold (e.g., CP length).

[0114] Figure 5 Shown in Figure 3 The method performed in the first TRP (service TRP) of the embodiment.

[0115] exist Figure 5 In step 501, the first TRP 310a sends an RRC reconfiguration message for measurement reporting to the UE 320.

[0116] In step 502, the first TRP 310a sends a first SSB to the UE 320.

[0117] In step 503, the first TRP 310a receives a measurement report message from the UE, the measurement report message including RTD information based on the reception time of the first SSB and the second SSB sent from the second TRP 310b.

[0118] In step 504, the first TRP 310a determines whether the RTD associated with the UE 320 satisfies the RTD limit based on the RTD information. Specifically, the TRP 310a determines whether the RTD associated with the UE 320 is within (less than) a threshold value (eg, CP length) based on the RTD information.

[0119] In step 505, when the RTD related to the UE 320 is less than the threshold, the first TRP 310a determines / recognizes that the RTD is valid, and sends an RRC reconfiguration message for multiple TRPs (ie, for adding the second TRP 310b) to the UE 320.

[0120] In step 506, when the RTD related to the UE 320 is greater than the threshold, the first TRP 310a determines / recognizes that the RTD is invalid and does not configure multiple TRPs for the UE 320 (i.e., in this case, the second TRP 310b is not added). When the RTD is equal to the threshold, it can be determined to be valid or invalid according to the setting.

[0121] Figure 6 A flowchart of a method for supporting multi-TRP operation based on an RTD measurement report of a base station (TRP) in a wireless communication system according to an embodiment of the present disclosure is shown.

[0122] exist Figure 6 In the example of , the multi-TRP operation includes sending an uplink (UL) signal by the UE to two or more TRPs. Before performing the multi-TRP operation, the first TRP 610a, which is the serving TRP, sends a measurement request to the second TRP 610b, which is the neighbor TRP, to determine whether to perform the multi-TRP operation. Thereafter, the second TRP 620b receives a physical random access channel (PRACH) preamble from the UE 620 to measure the transmission delay, and sends the measurement result to the first TRP 610a. The first TRP 610a measures / identifies the RTD (defined as the difference between the first transmission delay in the path from the UE 620 to the first TRP 610a and the second transmission delay in the path from the UE 620 to the second TRP 620a), and determines whether to perform (whether to set) the multi-TRP operation based on the RTD. Figure 6 The example proposes a base station (TRP)-based RTD measurement reporting method, wherein, when it is determined to perform multi-TRP operation in the first TRP 610a as described above, the first TRP 610a and the second TRP 620a collaborate to perform multi-TRP operation on the UL.

[0123] exist Figure 6 In the embodiment, the indication T RTD The RTD can be defined as follows in Equation 3.

[0124] [Formula 3]

[0125] T RTD = |First transmission delay - Second transmission delay|

[0126] First transmission delay: the transmission delay between UE and service TRP

[0127] Second transmission delay: the transmission delay between the UE and the neighbor TRP

[0128] exist Figure 6 In step 601, the first TRP 610a sends a transmission delay measurement request message for a measurement request related to a multi-TRP operation to the second TRP 610b. Here, the transmission delay measurement request message may include a dedicated preamble index that can be used to measure the transmission delay in the path between the UE 620 and the second TRP 610b. The dedicated preamble index can use at least one of the dedicated preamble indexes allocated in the contention-free random access process.

[0129] In step 602, the first TRP 610a receives a confirmation message for the transmission delay measurement request from the second TRP 610b. The second TRP 610b can identify whether the dedicated preamble code index received in step 601 is available in the second TRP 610b, and reply to the first TRP 610a through a confirmation message in step 602 whether the index is available.

[0130] In step 603, when the dedicated preamble index is available in the second TRP 610b, the first TRP 610a sends an RRC reconfiguration message for allocating a dedicated preamble corresponding to the dedicated preamble index to the UE 620. In step 604, the first TRP 610a receives an RRC reconfiguration complete message from the UE 620 to which the dedicated preamble is allocated.

[0131] Thereafter, in step 605, the second TRP 610b receives a PRACH preamble corresponding to the dedicated preamble index from the UE 620. For example, the PRACH preamble is transmitted through msg.1 in the random access process. In this case, since the second TRP 610b has identified the dedicated preamble index in steps 601 and 602, it can recognize that the PRACH preamble is not for random access but for transmission delay measurement of multi-TRP operation.

[0132] In step 606, the second TRP 620b measures the transmission delay of the PRACH preamble code in the path from the UE 620 to the second TRP 620a (i.e., the second transmission delay), and in step 607, the second TRP 620b sends a response message to the UE 620 (e.g., a random access response (RAR), i.e., msg.2 in the random access process).

[0133] In step 608, the first TRP 610a receives a report message including the measurement result of the second transmission delay from the second TRP 620b, and sends a response message to the second TRP 620b in step 609.

[0134] In step 610, the first TRP 610a measures / identifies the RTD (defined as the difference between a first transmission delay in a path from the UE 620 to the first TRP 610a and a second transmission delay in a path from the UE 620 to the second TRP 620a), and determines / identifies whether the RTD satisfies the RTD limit. Since the first TRP 610a is the serving TRP of the UE 620, the first TRP 610a can measure / identify the first transmission delay. In step 610, the first TRP 610a can determine whether the RTD limit is satisfied based on whether the RTD is within a threshold range. Figure 6 In the example, you can Figure 3 The CP length is used as an example, or a preset value that does not cause performance degradation due to cross-link interference in the UL is used as the threshold.

[0135] In step 611, when the RTD is less than the threshold, the first TRP 610a determines / recognizes that the RTD is valid, and sends an RRC reconfiguration message for multiple TRPs (ie, for adding the second TRP 610b) to the UE 620.

[0136] In step 612, when the RTD is greater than the threshold, the first TRP 610a determines / recognizes that the RTD is invalid and does not configure multiple TRPs for the UE 620 (ie, in this case, the second TRP 610b is not added).

[0137] Therefore, according to the above Figure 3 In an embodiment, the serving TRP measures / identifies the RTD between multiple TRPs before performing the multi-TRP operation, and when the RTD is greater than a predetermined threshold, the serving TRP may prevent the multi-TRP operation from being performed to prevent UL performance degradation due to cross-link interference. When the RTD is less than the predetermined threshold, the serving TRP may cooperate with the neighbor TRP to stably perform the multi-TRP operation to receive UL signals from the UE.

[0138] At the same time, Figure 6 In the embodiment of the present invention, when the first TRP 610a and the second TRP 620b are connected to the same base station (gNB) (or distributed unit (DU)), Figure 6 The operations in steps 601, 602, 607 and 608 can be processed by the same base station (gNB), so in this case, the process of sending and receiving corresponding messages between the first TRP 610a and the second TRP 620b can be omitted.

[0139] At the same time, Figure 6 In the example of , the RTD can be represented using, for example, a mapping index for each RTD range. (e.g., timing advance in TS 38.211)

[0140] In addition, Figure 6 In step 601, the target of the first TRP 610a sending the transmission delay measurement request message can be determined by the following methods 5-1) and 5-2).

[0141] 5-1) Method of unicast transmission to a specific TRP

[0142] 5-2) Method of broadcasting transmission to multiple TRPs

[0143] In addition, method 5-2 can also be used when selecting multiple service TRPs based on UE (for example, it can also be applied to ultra-dense networks (UDN), cell-free networks, etc.).

[0144] also, Figure 6 The transmission delay measurement request message in step 601 may include at least one of RACH related information such as PRACH format (i.e., rach-ConfigCommon IE as shown in Table 4 below) and dedicated preamble index, and the confirmation message for the transmission delay measurement request in step 602 may include at least one of RACH opportunity (RO) mapping setting and SSB bit information. In addition, Figure 6 In step 605, the UE 620 and the second TRP 610b can recognize that the PRACH preamble code transmitted / received using the dedicated preamble code index is used for transmission delay measurement, not for random access. In step 607, a response message RAR is sent to the UE 620 so as not to perform a retransmission operation of the PRACH preamble code, and the UE 620 does not perform a separate additional operation after receiving the response message RAR. In addition, in Figure 6The report message containing the measurement result of the second transmission delay in step 608 may include information such as a dedicated preamble index, a transmission delay value, and an SSB index mapped to a RACH opportunity (RO) as a transmission delay measurement target. For the information element (IE) shown in Table 4 below, reference may be made to TS 38.331.

[0145] [Table 4]

[0146] Figure 7 Shown in Figure 6 The method is performed in the UE in the embodiment.

[0147] exist Figure 7 In step 701, the UE 620 receives an RRC reconfiguration message for dedicated preamble allocation from the first TRP 610a. The RRC reconfiguration message may include an index of a dedicated preamble that can be used to measure a transmission delay in a path between the UE 620 and the second TRP 610b.

[0148] In step 702, the UE 620 allocated with the dedicated preamble sends an RRC reconfiguration complete message to the first TRP 610a.

[0149] In step 703, UE 620 sends a PRACH preamble corresponding to the dedicated preamble index to the second TRP 610b.

[0150] In step 704, the UE 620 receives a response message (eg, a random access response (RAR), ie, msg.2 in the random access procedure) to the transmission of the PRACH preamble from the second TRP 610b.

[0151] Thereafter, in step 705, based on the determination of the first TRP 610a, the UE 620 receives an RRC reconfiguration message for multiple TRPs (ie, for adding the second TRP 610b) from the first TRP 610a as a response to satisfying the RTD limit.

[0152] Figure 8 Shown in Figure 6 The method performed in the first TRP (service TRP) of the embodiment.

[0153] exist Figure 8 In step 801, the first TRP 610a sends a transmission delay measurement request message to the second TRP 610b. The transmission delay measurement request message may include a dedicated preamble code index that can be used to measure the transmission delay in the path between the UE 620 and the second TRP 610b.

[0154] In step 802, the first TRP 610a receives a confirmation message for the transmission delay measurement request from the second TRP 610b. The confirmation message may include information indicating that the dedicated preamble index is available in the second TRP 610b.

[0155] In step 803, the first TRP 610a sends an RRC reconfiguration message for dedicated preamble allocation to the UE 620. The RRC reconfiguration message may include a dedicated preamble index. In step 804, the first TRP 610a receives an RRC reconfiguration complete message from the UE 620 to which the dedicated preamble is allocated.

[0156] In step 805, the first TRP 610a receives a report message including a transmission delay measurement result from the second TRP 610b, which has received a PRACH preamble corresponding to a dedicated preamble index from the UE 620. The transmission delay measurement result is a measurement result of the transmission delay (i.e., the second transmission delay) of the PRACH preamble in a path from the UE 620 to the second TRP 620a.

[0157] In step 806, the first TRP 610a sends a response message to the second TRP 610b for the report message containing the transmission delay measurement result.

[0158] In step 807, the first TRP 610a measures / identifies the RTD (defined as the difference between the first transmission delay in the path from the UE 620 to the first TRP 610a and the second transmission delay in the path from the UE 620 to the second TRP 620a), and determines / identifies whether the RTD satisfies the RTD limit. Since the first TRP 610a is the serving TRP of the UE 620, the first TRP 610a can measure / identify the first transmission delay.

[0159] In step 808, when the RTD is less than the threshold, the first TRP 610a determines / recognizes that the RTD is valid, and sends an RRC reconfiguration message for multiple TRPs (ie, for adding the second TRP 610b) to the UE 620.

[0160] In step 809, when the RTD is greater than the threshold, the first TRP 610a determines / recognizes that the RTD is invalid and does not configure multiple TRPs for the UE 620 (ie, in this case, the second TRP 610b is not added).

[0161] Fig. 9 Shown in Figure 6 The method performed in the second TRP (neighbor TRP) of the embodiment.

[0162] exist Fig. 9 In step 901, the second TRP 610b receives a transmission delay measurement request message from the first TRP 610a, and the transmission delay measurement request message includes a dedicated preamble code index that can be used to measure the transmission delay in the path between the UE 620 and the second TRP 610b.

[0163] In step 902, the second TRP 610b sends a confirmation message to the first TRP 610a. The second TRP 610b can identify whether the dedicated preamble index received in step 901 is available in the second TRP 610b, and reply to the first TRP 610a whether the index is available through a confirmation response message in step 902.

[0164] Thereafter, in step 903, the second TRP 610b receives a PRACH preamble from a UE to which a dedicated preamble corresponding to a dedicated preamble index is allocated.

[0165] In step 904, the second TRP 610b measures the transmission delay of the PRACH preamble code in the path from the UE 620 to the second TRP 620a (ie, the second transmission delay), and in step 905, the second TRP 620b sends a response message to the UE 620 (eg, a random access response (RAR), ie, msg.2).

[0166] In step 906, the second TRP 620b sends a report message including the measurement result of the second transmission delay to the first TRP 610a, and receives a response message to the report message from the first TRP 610a in step 907. Thereafter, when it is determined in the first TRP 610a to perform a multi-TRP operation, the second TRP 620a cooperates with the first TRP 610a to perform the multi-TRP operation on the UL.

[0167] Fig.10 An example of the configuration of a UE in a wireless communication system according to an embodiment of the present disclosure is shown.

[0168] exist Fig.10 In the embodiment, the UE may include a processor 1001, a transceiver 1003 and a memory 1005. Figure 7 The processor 1001, the transceiver 1003 and the memory 1005 of the UE can be combined according to Figures 1 to 9 The method described above is used to operate. However, the components of the UE are not limited to these. For example, the UE may include more or fewer components than the above components. The processor 1001, the transceiver 1003 and the memory 1005 may be implemented in the form of at least one chip.

[0169] The transceiver 1003 is collectively referred to as a receiver and a transmitter, and can transmit and receive signals with the UE or other network entities. The transmitted and received signals may include at least one of control information and data. To this end, the transceiver 1003 may include an RF transmitter for up-converting and amplifying the transmitted signal, and an RF receiver for low-noise amplifying the received signal and down-converting the frequency of the received signal. This is merely one embodiment of the transceiver 1003, and the components of the transceiver 1003 are not limited to the RF transmitter and the RF receiver. In addition, the transceiver 1003 can receive signals through the communication scheme defined in the 3GPP standard, output the signals to the processor 1001, and send the signals output from the processor 1001. In addition, the transceiver 1003 can receive signals and output them to the processor 1001, and send the signals output from the processor 1001 to another network entity through the network. The memory 1005 can store information according to the communication scheme defined in the 3GPP standard. Figures 1 to 9 The program and data required for the operation of the UE according to at least one embodiment of the present invention. The memory 1005 may store control information and / or data contained in the signal obtained by the UE. The memory 1005 may include a storage medium such as a ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. The processor 1001 may control a series of processes so that the UE can perform the following operations according to the present invention: Figures 1 to 9 The processor 1001 may include at least one processor.

[0170] Fig.11 An example of the configuration of a TRP (or base station) in a wireless communication system according to an embodiment of the present disclosure is shown.

[0171] Reference Fig.11 , the TRP (or base station) may include a processor 1101, a transceiver 1103, a communication interface 1105, and a memory 1107. The processor 1101, the transceiver 1103, the communication interface 1105, and the memory 1107 of the TRP may be combined Figures 1 to 9 The method described above is used to operate. However, the components of the TRP are not limited to these. For example, the TRP may include more or fewer components than the above components. The processor 1101, the transceiver 1103, the communication interface 1105 and the memory 1105 may be implemented in the form of at least one chip.

[0172] The transceiver 1103 is collectively referred to as a receiver and a transmitter, and can transmit and receive signals with the UE through a wireless network. In addition, the TRP (or base station) can transmit and receive signals with another network entity (for example, another TRP (or base station)) through a wired network or a wireless network through the communication interface 1105. The signal transmitted and received by the transceiver 1103 or the communication interface 1105 may include at least one of control information and data. In addition, the transceiver 1103 and the communication interface 1105 can receive signals through the communication scheme defined in the 3GPP standard, output the signals to the processor 1101, and send the signals output from the processor 1101 to another network entity. The memory 1105 can store data according to the communication scheme defined in the 3GPP standard. Figures 1 to 9 In addition, the memory 1105 may store control information and / or data contained in the signal obtained by the network entity. The memory 1105 may include a storage medium such as ROM, RAM, hard disk, CD-ROM and DVD, or a combination of storage media. The processor 1101 may control a series of processes so that the TRP can be based on Figures 1 to 9 The processor 1001 may include at least one processor.

[0173] The method according to the embodiment described in the specification or claims of the present disclosure may be implemented by hardware, software, or a combination of hardware and software. When the processor 1001 or 1101 is implemented by software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. One or more programs include instructions that enable an electronic device to perform the method according to the embodiment described in the specification or claims of the present disclosure.

[0174] The program (software module or software) may be stored in a random access memory, a non-volatile memory including a flash memory, a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic disk storage device, an optical disk ROM, a digital versatile disk (DVD) or other types of optical storage devices, or a magnetic tape. Alternatively, the program may be stored in a memory consisting of a combination of all or part thereof. As each constituent memory, a plurality of memories may be included. The program may be stored in an additional storage device accessible through a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN) or a storage area network (SAN) or a communication network consisting of a combination thereof. The storage device may be connected to a device that performs an embodiment of the present disclosure through an external port. A separate storage device on a communication network may be connected to a device that performs an embodiment of the present disclosure.

[0175] In the above-mentioned specific embodiments, the components included in the present disclosure are expressed in singular or plural form according to the specific embodiment proposed. However, the singular or plural form is selected to be suitable for the context suggested for ease of description, and the present disclosure is not limited to singular or plural components. As used herein, unless the context clearly indicates otherwise, even if expressed in the singular form, it may include the plural, or even if expressed in the plural form, it may include the singular.

[0176] Although specific embodiments of the present invention have been described above, various changes may be made thereto without departing from the scope of the present invention. Therefore, the scope of the present disclosure should not be limited to the above embodiments, but should be defined by the claims and their equivalents.

Claims

1. A method for supporting a multi-transceiver point TRP operation by a user equipment UE in a wireless communication system, the method comprising: receiving a first synchronization signal block (SSB) from a first TRP which is a serving TRP for the UE; receiving a second SSB from a second TRP that is a neighbor TRP of the first TRP; identifying a receive time difference RTD between the first SSB and the second SSB; as well as When a measurement report event is triggered, a measurement report message including information indicating the RTD is sent to the first TRP.

2. The method according to claim 1, further comprising: In response to satisfying the RTD limit, a radio resource control (RRC) reconfiguration message is received from the first TRP to add the second TRP for the multi-TRP operation.

3. The method according to claim 2, wherein: In the case where the RTD is less than a threshold, the RTD limit is satisfied, and In the case where the RTD is greater than the threshold, the second TRP is not added.

4. The method according to claim 1, wherein: At least one of the transmission period and SSB index of the first SSB and the second SSB is the same.

5. The method according to claim 1, wherein: The information indicating the RTD includes at least one of the following: The RTD corresponding to the SSB index with the maximum received signal strength; The average RTD for multiple SSB indexes; and RTD for a defined number of SSB indices selected based on signal strength or signal quality.

6. A UE in a wireless communication system, comprising: Transceiver; as well as Processor, configured as: receiving, by the transceiver, a first synchronization signal block SSB from a first transceiver point TRP which is a serving TRP for the UE; receiving, by the transceiver, a second SSB from a second TRP that is a neighbor TRP of the first TRP; identifying a receive time difference RTD between the first SSB and the second SSB; as well as When a measurement report event is triggered, a measurement report message including information indicating the RTD is sent to the first TRP via the transceiver.

7. The UE according to claim 6, adapted to operate according to the method according to any one of claims 2-5.

8. A method for supporting multi-transceiver point TRP operation by a serving TRP of a user equipment UE in a wireless communication system, the method comprising: Sending a transmission delay measurement request message to a neighbor TRP of the serving TRP, the transmission delay measurement request message including information about a dedicated preamble available for measuring the transmission delay in a path between the UE and the neighbor TRP; Allocating the dedicated preamble to the UE; Receiving, from the neighbor TRP that receives the PRACH preamble from the UE, a report message including a transmission delay measurement result of a physical random access channel PRACH preamble; as well as Based on the received transmission delay measurement results, determine whether to perform multiple TRP operations on the UE.

9. The method according to claim 8, wherein: The determination includes: identifying a first transmission delay in a path from the UE to the serving TRP; for the received transmission delay measurement result, identifying a second transmission delay in a path from the UE to the neighbor TRP; and A receive time difference RTD between the first transmission delay and the second transmission delay is identified.

10. The method according to claim 9, further comprising: When the RTD is less than a threshold value, determining that the RTD is valid; as well as A radio resource control (RRC) reconfiguration message is sent to the UE to add the neighbor TRP for the multi-TRP operation.

11. The method according to claim 10, further comprising: In the case where the RTD is greater than the threshold, determining that the RTD is invalid; as well as Determine not to perform the multi-TRP operation.

12. The method according to claim 8, wherein: The dedicated preamble is used for transmission delay measurements associated with the configuration of the multi-TRP operation.

13. A service transceiver point TRP in a wireless communication system, the service TRP comprising: Transceiver; Communication interface; as well as Processor, configured as: Sending a transmission delay measurement request message to a neighbor TRP of the serving TRP through the communication interface, the transmission delay measurement request message including information about a dedicated preamble available for measuring the transmission delay in a path between the UE and the neighbor TRP; allocating the dedicated preamble to the UE by the transceiver; Receiving, through the communication interface, a report message including a transmission delay measurement result of a physical random access channel PRACH preamble code from the neighbor TRP that receives the PRACH preamble code from the UE; as well as Based on the received transmission delay measurement results, determine whether to perform multiple TRP operations on the UE.

14. The service TRP according to claim 13 is suitable for operating according to the method described in any one of claims 9-12.

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