KR20240024590A - Method and apparatus for supporting multi-transmission-reception point (multi-trp) operation in a wireless communication system - Google Patents

Abstract

The present disclosure relates to a method and apparatus for supporting multiple TRP operations in a wireless communication system. According to an embodiment of the present disclosure, a method for a terminal to support multiple TRP operations in a wireless communication system includes: A process of receiving a first SSB (synchronization signal block) from a first TRP that is a serving TRP, a process of receiving a second SSB from a second TRP that is a neighboring TRP of the first TRP, and the first SSB and the second It includes the process of checking the reception timing difference (RTD) of the SSB and, when a measurement report event is triggered, transmitting a measurement report message including information indicating the RTD to the first TRP.

Description

Method and apparatus for supporting multiple transmission/reception point operation in a wireless communication system {METHOD AND APPARATUS FOR SUPPORTING MULTI-TRANSMISSION-RECEPTION POINT (MULTI-TRP) OPERATION IN A WIRELESS COMMUNICATION SYSTEM}

This disclosure relates to a method and apparatus related to the operation of multiple TRPs in a wireless communication system.

5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and includes frequencies below 6 GHz such as 3.5 gigahertz (3.5 GHz) ('Sub 6GHz Sub band, as well as millimeter wave (mmWave) such as 28 GHz and 39 GHz. It can also be implemented in the ultra-high frequency band called 'Above 6GHzbo'. In addition, in the case of 6G mobile communication technology, which is called the system of 'Beyond 5G', the transmission speed is 50 times faster than 5G mobile communication technology and 1/10th of the speed. Implementations in Terahertz bands (e.g., 95 GHz to 3 THz) are being considered to achieve ultra-low latency.

In the early days of 5G mobile communication technology, there were concerns about ultra-wideband services (enhanced Mobile BroadBand, eMBB), ultra-reliable low-latency communications (URLLC), and massive machine-type communications (mMTC). With the goal of satisfying service support and performance requirements, efficient use of ultra-high frequency resources, including beamforming and massive array multiple input/output (Massive MIMO) to alleviate radio wave path loss and increase radio transmission distance in ultra-high frequency bands. Various numerology support (multiple subcarrier interval operation, etc.) and dynamic operation of slot format, initial access technology to support multi-beam transmission and broadband, definition and operation of BWP (Band-Width Part), large capacity New channel coding methods such as LDPC (Low Density Parity Check) codes for data transmission and Polar Code for highly reliable transmission of control information, L2 pre-processing, and dedicated services specialized for specific services. Standardization of network slicing, etc., which provides networks, has been carried out.

Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology, considering the services that 5G mobile communication technology was intended to support, based on the vehicle's own location and status information. V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience, and NR-U (New Radio Unlicensed), which aims to operate a system that meets various regulatory requirements in unlicensed bands. ), NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is not possible, positioning, etc. Physical layer standardization for technology is in progress.

In addition, IAB (IAB) provides a node for expanding the network service area by integrating intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, and wireless backhaul links and access links. Integrated Access and Backhaul, Mobility Enhancement including Conditional Handover and DAPS (Dual Active Protocol Stack) handover, and 2-step Random Access (2-step RACH for simplification of random access procedures) Standardization in the field of wireless interface architecture/protocol for technologies such as NR) is also in progress, and a 5G baseline for incorporating Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technology Standardization in the field of system architecture/services for architecture (e.g., Service based Architecture, Service based Interface) and Mobile Edge Computing (MEC), which provides services based on the location of the terminal, is also in progress.

When this 5G mobile communication system is commercialized, an explosive increase in connected devices will be connected to the communication network. Accordingly, it is expected that strengthening the functions and performance of the 5G mobile communication system and integrated operation of connected devices will be necessary. To this end, eXtended Reality (XR) and Artificial Intelligence are designed to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR). , AI) and machine learning (ML), new research will be conducted on 5G performance improvement and complexity reduction, AI service support, metaverse service support, and drone communication.

In addition, the development of these 5G mobile communication systems includes new waveforms, full dimensional MIMO (FD-MIMO), and array antennas to ensure coverage in the terahertz band of 6G mobile communication technology. , multi-antenna transmission technology such as Large Scale Antenna, metamaterial-based lens and antenna to improve coverage of terahertz band signals, high-dimensional spatial multiplexing technology using OAM (Orbital Angular Momentum), RIS ( In addition to Reconfigurable Intelligent Surface technology, Full Duplex technology, satellite, and AI (Artificial Intelligence) to improve the frequency efficiency of 6G mobile communication technology and system network are utilized from the design stage and end-to-end. -to-End) Development of AI-based communication technology that realizes system optimization by internalizing AI support functions, and next-generation distributed computing technology that realizes services of complexity beyond the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources. It could be the basis for .

The present disclosure provides a method and apparatus for efficiently supporting multiple TRP operations in a wireless communication system.

Additionally, the present disclosure provides a terminal-based receive timing difference (RTD) measurement reporting method and device in a wireless communication system supporting multiple TRP operations.

Additionally, the present disclosure provides a base station (TRP)-based RTD measurement reporting method and device in a wireless communication system supporting multiple TRP operations.

According to an embodiment of the present disclosure, a method for a terminal to support multiple TRP operation in a wireless communication system includes a process of receiving a first synchronization signal block (SSB) from a first TRP, which is a serving TRP of the terminal, and the first A process of receiving a second SSB from a second TRP, which is a neighboring TRP of the TRP, a process of checking a reception timing difference (RTD) of the first SSB and the second SSB, and when a measurement report event is triggered, the second SSB It includes the process of transmitting a measurement report message containing information indicating the RTD to 1 TRP.

The method further includes receiving, in response to the RTD limit being satisfied, a radio resource control (RRC) reset message adding the second TRP for the multi-TRP operation from the first TRP.

In the method, if the RTD is less than the threshold value, the RTD limit is satisfied, and if the RTD is greater than the threshold value, the second TRP is not added.

In the above method, at least one of the transmission period and SSB index of the first SSB and the second SSB is the same.

In the above method, the information representing the RTD includes the RTD corresponding to the SSB index with the strongest received signal strength, the average RTD for a plurality of SSB indexes, and a certain number of SSB indexes selected based on signal strength or signal quality. Include at least one of the RTDs for

In addition, in a wireless communication system according to an embodiment of the present disclosure, a terminal receives a first SSB from a first TRP that is a serving TRP of the terminal through a transceiver and the transceiver, and a neighbor TRP of the first TRP through the transceiver. receives a second SSB from a second TRP, checks the reception timing difference (RTD) of the first SSB and the second SSB, and when a measurement report event is triggered, sends the second SSB to the first TRP through the transceiver. and a processor configured to transmit a measurement report message including information representative of the RTD.

In addition, according to an embodiment of the present disclosure, the method for the serving TRP of a terminal to support multiple TRP operations in a wireless communication system can be used to measure the propagation delay in the path between the terminal and the neighboring TRP to the neighboring TRP of the serving TRP. A process of transmitting a propagation delay measurement request message containing information about a dedicated preamble, a process of allocating the dedicated preamble to the terminal, and a process of transmitting a propagation delay measurement request message containing information about a dedicated preamble, and a process of allocating the dedicated preamble to the terminal, from the neighboring TRP receiving a physical random access channel (PRACH) preamble from the terminal. It includes a process of receiving a report message including a propagation delay measurement result of the PRACH preamble, and a process of determining whether to perform a multiple TRP operation for the terminal based on the received propagation delay measurement result.

In the method, the determining process includes confirming the first propagation delay on the path from the terminal to the serving TRP, and using the received propagation delay measurement result to determine the second propagation delay on the path from the terminal to the neighboring TRP. It includes a process of checking and a process of checking a reception timing difference (RTD) between the first propagation delay and the second propagation delay.

The method further includes determining that the RTD is valid when the RTD is less than a threshold, and transmitting an RRC reset message adding the neighbor TRP to the terminal for the multi-TRP operation.

The method further includes determining that the RTD is invalid when the RTD is greater than the threshold value, and determining not to perform the multiple TRP operation.

In the above method, the dedicated preamble is used to measure propagation delay related to setting up the multi-TRP operation.

In addition, in a wireless communication system according to an embodiment of the present disclosure, the serving TRP uses a transceiver, a communication interface, and a neighbor TRP of the serving TRP through the communication interface to measure propagation delay in the path between the terminal and the neighbor TRP. Transmits a propagation delay measurement request message containing information about a possible dedicated preamble, assigns the dedicated preamble to the terminal through the transceiver, and receives a PRACH preamble from the terminal through the communication interface. and a processor configured to receive a report message including a propagation delay measurement result of the PRACH preamble from a neighboring TRP and determine whether to perform a multiple TRP operation for the terminal based on the received propagation delay measurement result.

1 is a diagram illustrating an example of a wireless communication system to which multiple TRP operations are applied according to an embodiment of the present disclosure;
2A and 2B are diagrams illustrating an example of a reception timing difference (RTD) for determining whether a multiple TRP operation is effective according to an embodiment of the present disclosure;
3 is a flowchart showing a terminal-based RTD measurement reporting method in a wireless communication system supporting multiple TRP operations according to an embodiment of the present disclosure;
Figure 4 is a diagram showing a method performed in the terminal in the embodiment of Figure 3;
Figure 5 is a diagram showing a method performed in the first TRP (serving TRP) in the embodiment of Figure 3;
Figure 6 is a flow chart showing a base station (TRP)-based RTD measurement reporting method in a wireless communication system supporting multiple TRP operations according to an embodiment of the present disclosure;
Figure 7 is a diagram showing a method performed in the terminal in the embodiment of Figure 6;
Figure 8 is a diagram showing a method performed in the first TRP (serving TRP) in the embodiment of Figure 6;
Figure 9 is a diagram showing a method performed in the second TRP (neighboring TRP) in the embodiment of Figure 6;
10 is a diagram illustrating an example configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure, and
FIG. 11 is a diagram illustrating an example configuration of a base station (TRP) in a wireless communication system according to an embodiment of the present disclosure.

Hereinafter, embodiments of the present disclosure will be described in detail with the accompanying drawings. Additionally, when describing the present disclosure, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of the functions in the present disclosure, and may vary depending on the intention or custom of the user or operator. Therefore, the definition should be made based on the contents throughout this specification.

The advantages and features of the present disclosure and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms, and the present embodiments are merely intended to ensure that the disclosure is complete and are within the scope of common knowledge in the technical field to which the present disclosure pertains. It is provided to fully inform those who have the scope of the invention, and the present disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagram diagrams can be performed by computer program instructions.

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). Additionally, it should be noted that in some alternative execution examples it is possible for the functions mentioned in the blocks to occur out of order. For example, it is possible for two blocks shown in succession to be performed substantially at the same time, or it is possible for the blocks to be performed in reverse order depending on the corresponding function.

At this time, the term '~unit' used in this embodiment refers to software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and '~unit' performs certain roles. do. However, '~part' is not limited to software or hardware. The '~ part' may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Therefore, as an example, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and 'parts' may be combined into a smaller number of components and 'parts' or may be further separated into additional components and 'parts'. Additionally, components and 'parts' may be implemented to regenerate one or more CPUs within a device or a secure multimedia card. Additionally, in an embodiment, '~ part' may include one or more processors.

In the present disclosure, “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 “A, Each of phrases such as “at least one of B, or C” may include any one of the items listed together in the corresponding phrase, or any possible combination thereof. Terms such as "first", "second", or "first" or "second" may be used simply to distinguish one component from another, and may refer to that component in other respects, such as importance or order) is not limited.

A term used in the description of the present disclosure to identify a connection node, a term referring to network entities, a term referring to messages, a term referring to an interface between network objects, and various identification information. The terms used are exemplified for convenience of explanation. Accordingly, the present invention is not limited to the terms described below, and other terms referring to objects having equivalent technical meaning may be used.

For convenience, this disclosure uses terms and names defined in the 5GS and NR standards defined by the 3rd Generation Partnership Project (3GPP) organization. Embodiments of the present disclosure will be described using the example of a 5G system for convenience, but the embodiments of the present disclosure are not limited by terms and names in the 5G system, and can be equally applied to wireless communication systems that comply with other standards. .

In the present disclosure, a base station (BS) is a network entity that performs resource allocation for a terminal and can communicate with the terminal through a wireless network, including eNode B, Node B, gNB, RAN (Radio Access Network), and AN. It may be at least one of (Access Network), RAN node, Integrated Access/Backhaul (IAB) node, radio access unit, base station controller, node on the network, or TRP (transmission reception point). A terminal (user equipment: UE) may be at least one of a terminal, MS (Mobile Station), cellular phone, smartphone, computer, or multimedia system capable of performing communication functions.

Unlike existing systems, the 5G system can support not only services requiring high transmission speeds, but also services with very short transmission delays and services requiring high connection density. In a wireless communication system using multiple base stations, multiple cells, TRPs, or beams, coordinated transmission between base stations, cells, TRPs, or/and beams can strengthen the signal strength received by the terminal. , interference control between each base station, cell, TRP or/and beam can be efficiently performed to satisfy various service requirements. As an example, joint transmission (JT) using multiple TRPs is one of the representative transmission technologies for cooperative communication, and increases the strength or processing rate of the signal received by the terminal by transmitting a signal to one terminal through multiple TRPs. It is a technique to do.

Additionally, in the 5G system, a synchronization signal block (SSB) is a physical layer signal block that includes a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The base station can transmit one or more synchronization signal blocks (SSBs) to the terminal within 5 ms, and each SSB transmitted from the base station can be distinguished by an SSB index. The terminal can detect PSS and SSS in the initial access stage and decode the PBCH. The terminal can obtain a MIB (master information block) from the PBCH, and control resource set (CORESET) #0 (which may correspond to a control resource set with a control resource set index of 0) through the MIB. You can get it set. In addition, the terminal can perform monitoring on control resource set #0 assuming that the selected SSB and demodulation reference signal (DMRS) transmitted in control resource set #0 are in QCL (Quasi Co Location) (QCL assumption). The terminal can receive system information through downlink control information transmitted from control resource set #0. The terminal can obtain RACH (Random Access Channel)-related configuration information necessary for initial access from the received system information. The terminal can transmit PRACH (Physical RACH) to the base station in consideration of the selected SSB index, and the base station that receives the PRACH can obtain information about the SSB index selected by the terminal. The base station can know which SSB the terminal has selected among SSBs and monitors the control resource set #0 associated with it.

In addition, beam management in the 5G system involves performing communication by selecting the optimal transmission beam pair of a transmission beam on the transmitting side and a reception beam on the receiving side. In the initial cell search process, the terminal receives SSBs transmitted from the base station. In this process, the base station can sequentially transmit multiple SSBs using multiple different transmission beams, and the terminal can sequentially transmit multiple received beams. By forming the received signal strength of each of multiple SSBs, the optimal receiving beam can be found. The reception beam found in this way and the transmission beam that transmitted the corresponding SSB become the initial transmission and reception beam pair. And when the initial transmission/reception beam pair is selected, the optimal transmission/reception beam pair can be determined through a beam adjustment procedure using CSI-RS.

In the present disclosure, the SSB may be transmitted through a base station (for example, a TRP), and SSB(s) with the same or different SSB index may be transmitted through multiple TRPs. In the present disclosure, when receiving SSB(s) from TRP(s), the terminal can measure/check the receive timing of each SSB, and sends information related to the measured reception timing for each SSB to the terminal. It can be transmitted to the serving TRP.

Additionally, in the present disclosure, the TRP may provide higher layer signaling information (or configuration information) to the terminal, and the higher layer signaling may be signaling corresponding to at least one or a combination of one or more of the following signaling.

- MIB (Master Information Block)

- SIB (System Information Block) or SIB

- RRC (Radio Resource Control)

- MAC (Medium Access Control) CE (Control Element)

Additionally, in the present disclosure, the TRP may provide L1 signaling information to the terminal, and the L1 signaling information may be signaling corresponding to at least one or a combination of one or more of the following signaling methods using the physical layer channel or signaling.

- PDCCH (Physical Downlink Control Channel)

- DCI (Downlink Control Information)

- UE-specific DCI

- Group common DCI

- Common DCI

1 is a diagram illustrating an example of a wireless communication system to which multiple TRP operations are applied according to an embodiment of the present disclosure. 2A and 2B are diagrams for explaining an example of a reception timing difference (RTD) for determining whether a multiple TRP operation is possible according to an embodiment of the present disclosure. The example of FIG. 1 will be described with reference to FIGS. 2A and 2B.

Figure 1 shows a network environment in which multiple TRPs (TRP A, TRP B, TRP C) (110a, 110b, 110c) and multiple terminals (UE1, UE2, UE3) (120a, 120b, 120c) exist. An example is shown. At least two of the multiple TRPs (TRP A, TRP B, TRP C) (110a, 110b, 110c) are sent to at least one of the multiple terminals (UE1, UE2, UE3) (120a, 120b, 120c). It is possible to transmit and receive signals to and from a terminal through multiple TRP operations.

The multiple TRPs (TRP A, TRP B, TRP C) 110a, 110b, 110c may be connected to the same base station (e.g., gNB) or may be connected to different base stations (e.g., gNB). For example, TRP A and TRP B may be connected to the same base station, and TRP C may be connected to a different base station.

The multiple TRP operation includes multiple TRPs transmitting or receiving signals to and from a terminal through cooperative communication, and an example is joint transmission (JT) through multiple TRPs. If the reception timing difference (RTD), which represents the difference in propagation delays between multiple TRPs and the terminal, is within a threshold value, a multiple TRP operation can be performed. For example, the threshold may use the cyclic prefix (CP) length of an orthogonal frequency division multiplexing (OFDM) symbol. The CP length is an example of the threshold value, and the threshold value can be provided to the terminal in advance by the serving TRP through configuration information, or it is possible to use a value agreed in advance between the terminal and the serving TRP. In the present disclosure, the serving TRP and the neighboring TRP may be the serving base station and the neighboring base station, may be TRPs connected to the same gNB, or may be TRPs connected to different gNBs.

In the example of Figure 1, the downlink (DL) propagation delay (Tprop _A,1 ) (101) between TRP A (110a) and the terminal (UE1) (120a) and between TRP B (110b) and the terminal (UE1) (120a) The first RTD, which represents the difference between the DL propagation delay (Tprop _B,1 ) (102), 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 (i.e., If RTD between multi-TRPs ≪ CP length), TRP A (110a) and TRP B (110b) cooperate to provide DL to the UE1 (120a). Multiple TRP operations that transmit signals can be performed reliably.

In the example of Figure 1, the DL propagation delay (Tprop _{A,2) (101) between TRP A} (110a) and the terminal (UE2) (120b) and the DL propagation delay (Tprop A,2) (101) between TRP B (110b) and the terminal (UE2) (120b) The second RTD representing the difference between Tprop _B,2 )(102) can be measured as △Tprop _UE2 = |Tprop _A,2 - Tprop _B,2 | If the second RTD is within the CP length in the OFDM symbol (i.e., If RTD between multi-TRPs < CP Length), TRP A (110a) and TRP B (110b) cooperate to send a DL signal to the UE2 (120a). Transmitting multiple TRP operations may be performed.

In the example of Figure 1, the DL propagation delay (Tprop _{A,3) (105) between TRP A (} 110a) and the terminal (UE3) (120c) and the DL propagation delay (Tprop A,3) (105) between TRP C (110b) and the terminal (UE3) (120c) The third RTD, which represents the difference between Tprop _C,3 )(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 (i.e., If RTD between multi-TRPs > CP Length), TRP A (110a) and TRP C (110c) cooperate to send a DL signal to the terminal (UE3) (120c). Multiple TRP operations transmitting cannot be performed reliably. In this case, referring to FIGS. 2A and 2B, FIG. 2A illustrates a case where the reception window (Rx window) 201 of the UE3 (120c) starts at the end of the CP, and FIG. 2B shows the UE3 (120c) receiving window (Rx window) 201 starting at the end of the CP. This illustrates the case where the reception window (Rx window) 211 of (UE3) 120c starts at the beginning of the CP. The OFDM symbol transmitted from TRP C (110b) can be stably received in the reception window (Rx window) 201 of the terminal (UE3) 120c, but the OFDM symbol transmitted from TRP A (110a) has a CP length. A situation occurs in which stable reception cannot be performed in the reception window (Rx window) 201, 211 of the terminal (UE3) 120c due to the third RTD being out of alignment (203, 213).

In the present disclosure, before a multi-TRP operation is performed, the terminal can measure/check the RTD between multiple TRPs and transmit the RTD information to a serving TRP among the multiple TRPs. Based on the received RTD information, the serving TRP determines that the RTD is an invalid RTD if the RTD between multiple TRPs is greater than the CP length, prevents multiple TRP operations from being performed for the terminal, and prevents the RTD between multiple TRPs from being performed. If is smaller than the CP length, the RTD is determined to be a valid RTD and multiple TRP operations can be performed for the terminal. According to this disclosure, a situation in which RTD can be greatly issued (for example, a situation in which a DL signal from one TRP is received as LOS (line of sight) and a DL signal from another TRP is received as non-LOS, macro cell and In multiple TRP scenarios between small cells, or multiple TRP scenarios when a terminal moves at high speed, etc.), it is possible to efficiently determine whether multiple TRP operations are possible before multiple TRP operations.

Figure 3 is a flowchart showing a terminal-based RTD measurement reporting method in a wireless communication system supporting multiple TRP operations according to an embodiment of the present disclosure.

In the example of FIG. 3, multiple TRP operation involves the terminal receiving downlink (DL) signals from two or more TRPs. Before the multiple TRP operation is performed, the terminal 320 measures/checks the RTD between the multiple TRPs and reports it to the first TRP 310a operating as a serving TRP, and the first TRP 310a measures/checks the RTD between the multiple TRPs. Based on the confirmed RTD information, it is determined whether to perform (set or not to) the multi-TRP operation, and when the multi-TRP operation is determined, the first TRP (310a) and the second TRP (310b), which is a neighboring base station, cooperate to perform multi-TRP operation in the DL. We propose a terminal-based RTD measurement reporting method that performs TRP operation.

Specifically, in step 301 of FIG. 3, the terminal 320 receives an RRC reconfiguration message for measurement reporting related to multiple TRP operations from the first TRP 310a.

In step 302, the terminal 320 receives the first SSB from the first TRP 310a, and at this time, the terminal 320 can measure/check the reception timing of the first SSB.

In step 303, the terminal 320 receives the second SSB from the second TRP 310b, and at this time, the terminal 320 can measure/check the reception timing of the second SSB.

In step 304, when a measurement report (MR) event is triggered, the terminal 320 measures/checks the RTD between the first TRP 310a and the second TRP 310b. Additionally, when a measurement report (MR) event is triggered in step 304, the terminal 320 performs Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), or Signal Received Quality (SINR) for the first and second SSBs. to Interference Noise Ratio) can be measured.

In the embodiment of FIG. 3, T _RTD (i), which represents the RTD between the first TRP 310a, which is the serving TRP, and the second TRP 310b, which is the neighboring TRP, may be defined as <Equation 1> below.

<Equation 1>

T _RTD (i) = |T _SSB,S (i) - T _SSB,N (i)|

T _SSB,S (i): Receive timing of i-th SSB of the serving TRP

T _SSB,N (i) : Receive timing of i-th SSB of the neighbor TRP

In the above <Equation 1>, T _SSB,S (i) is the reception timing of the first SSB corresponding to the i-th SSB index received from the first TRP 310a, and T _SSB,N (i) is the reception timing of the second TRP This is the reception timing of the second SSB corresponding to the i-th SSB index received from (310b). In the example of <Equation 1>, the definition of RTD is that the SSB transmission period of the first TRP (310a) and the second TRP (310b) are the same, PCI (physical cell ID) is different, and an overlapping SSB index exists. The conditions are assumed.

In addition, in relation to the RTD measurement standard, the terminal 320 measures the reception timing for receiving the synchronization signal (PSS/SSS) from the first TRP 310a and the second TRP 310b, respectively, and measures the interval between the reception timings. RTD, which represents the difference, can be measured.

If the SSB burst map (= ssb-PositionsInBurst IE) or SSB period of the first TRP (310a) and the second TRP (310b) do not match, at least the SSB index having the same position One SSB may be transmitted from the first TRP 310a and the second TRP 310b, respectively.

The ssb-PositionsInBurst IE indicates the time domain position of the SSB transmitted in a half frame with an SS/PBCH block (i.e., SSB), as disclosed in TS 38.331. In the ssb-PositionsInBurst IE, the first/left bit corresponds to SSB index 0, and the second bit can be understood as SSB index 1. And in the ssb-PositionsInBurst IE, a bitmap value of 0 indicates that the corresponding SSB is not transmitted, and a value of 1 indicates that the SSB is transmitted.

As another example, if the conditions in Equation 1 above are not satisfied or the SSB cycle is different, the terminal 320 can measure/check the RTD through modulo/shift (MOD/shift) operation.

For example, if the SSB period (= ssb-periodicityServingCell IE) of the first TRP (310a) and the second TRP (310b) match, but there is no overlapping SSB index in the SSB burst map (= ssb-PositionsInBurst IE), TS 38.213 , Referring to section 4.1 Cell search, the SSB location and SSB index mapping method according to the subcarrier spacing length are described as shown in <Table 1> below. Based on the method in [Table 1] below, the terminal 320 determines the time difference between SSB indices for SSB bursts transmitted within the same SSB cycle (can be defined as T _shift in <Equation 2> below). Able to know. For example, in Case C: SCS = 30kHz w/ FR1 (3.5GHz), it can be seen that SSB indexes 0 and 1 have a difference of 6 symbols, and SSB indexes 0 and 2 have a difference of 14 symbols. Therefore, in the case where there is no overlapping SSB index in the SSB burst map (= ssb-PositionsInBurst IE), even if the first TRP (310a) and the second TRP (310b) transmit SSBs of different SSB indexes, the terminal 320 transmits the SSB index RTD can be measured/confirmed based on the time difference between them.

[Table 1]

As an example, T _RTD (i, j), which represents the RTD between the first TRP (310a), which is a serving TRP, and the second TRP (310b), which is a neighboring TRP, when there is no overlapping SSB index (i.e., the first TRP (310a) and If the second TRP (310b) transmits SSBs of different SSB indices), it can be defined as <Equation 2> below.

<Equation 2>

T _RTD (i, j) = |T _SSB,S (i) - T _SSB,N (j)| + T _shift

T _SSB,S (i): Receive timing of i-th SSB of the serving TRP

T _SSB,N (j) : Receive timing of j-th SSB of the neighbor TRP

T _shift : time difference between i-th SSB and j-th SSB

In the above <Equation 1>, T _SSB,S (i) is the reception timing of the first SSB corresponding to the i-th SSB index received from the first TRP (310a), and T _SSB,N (j) is the reception timing of the second TRP This is the reception timing of the second SSB corresponding to the j-th SSB index received from (310b). T _shift is the time difference between the i-th and j-th SSB indexes (i.e., the time difference expressed in 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)

Additionally, if the SSB cycles (= ssb-periodicityServingCell IE) of the first TRP (310a) and the second TRP (310b) do not match, and there is no overlapping SSB index among the SSB burst maps (= ssb-PositionsInBurst IE), the SSB cycle Even if the values are not the same, the candidate setting value of the configurable SSB cycle is set in the form of a multiple, so an overlap inevitably occurs, so even in this case, the terminal 320 has a multiple relationship (for example, the first TRP 310a and the second TRP 310a). The RTD can be measured/checked through modulo operation using (if the SSB cycle of the TRP (310b) is the least common multiple). In TS 38.331, the SSB period is exemplified as a candidate setting value in multiple form, such as ssb-periodicityServingCell ENUMERATED {ms5, ms10, ms20, ms40, ms80, ms160, spare2, spare1}.

Returning to the description of FIG. 3, in step 305, the terminal 320 transmits a measurement report message including RTD information indicating the RTD measured/confirmed in step 304 to the first TRP 310a.

In step 306, the first TRP 310a, which has received the RTD information, determines/checks whether the RTD associated with the terminal 320 satisfies the RTD limit. Specifically, the TRP 310a determines/checks whether the RTD associated with the terminal 320 is within (less than) a threshold value (eg, CP length) based on the RTD information.

In step 307, if the RTD associated with the terminal 320 is less than the threshold, the TRP 310a determines/confirms that the RTD is valid and for multiple TRPs (i.e. for addition of the second TRP 310b) An RRC reset message is sent to the terminal 320.

In step 308, if the RTD associated with the terminal 320 is greater than the threshold, the first TRP 310a determines/confirms that the RTD is invalid and does not set multiple TRPs for the terminal 320. (That is, in this case, the second TRP 310b is not added).

Therefore, according to the above-described embodiment of FIG. 3, before the multiple TRP operation is performed, the terminal measures/checks the RTD between multiple TRPs, and the serving TRP has an RTD greater than a set threshold (e.g. CP length, etc.). In this case, multiple TRP operations can be prevented from being performed to prevent DL performance degradation. When the RTD is smaller than a set threshold (e.g. CP length, etc.), the serving TRP can stably perform a multi-TRP operation to transmit a DL signal to the UE in cooperation with neighboring TRPs.

Meanwhile, in the present disclosure, the RTD information may transmit the T _RTD (i) value of <Equation 1> or the T _RTD (i, j) value of <Equation 2> as is, or may be configured in the following manner/ can be transmitted.

As an example, RTD information may be composed of multiple bits or 1 bit information as in methods 1-1) and 1-2) below.

1-1) multiple bits: A method of configuring RTD information with multiple bits representing the mapping index for each RTD range (e.g., Timing advanced in TS 38.211)

1-2) 1 bit: After the terminal measures the RTD, a method of configuring 1 bit of RTD information indicating whether multiple TRP addition is possible (ok or not ok) considering the SCS and CP type (normal or extended), etc.

Also, as an example, RTD information may be transmitted for each SSB using the methods 2-1) to 2-3) below (see example in [Table 2] below).

2-1) A method of transmitting an RTD corresponding to the best SSB index (with the strongest received signal strength) for the cell result included in the measurement report message in step 305.

2-2) A method of taking and transmitting the average RTD for a plurality of SSB indices for the cell result included in the measurement report message in step 305.

2-3) Method of transmitting RTD for N best SSB indices selected according to RSRP/RSRQ/SINR

[Table 2]

Also, as an example, RTD information may be transmitted through signaling/method methods 3-1) to 3-3) below.

3-1) A method of transmitting RTD information by adding a new field in a conventional measurement report message and a method of including configuration parameters for setting on/off the multi-TRP operation, where the measurement report (MR) trigger condition is the conventional method. A1/A2/... event conditions, etc. can be used.

3-2) How to set the target TRP for RTD measurement and transmit RTD information through uplink control information (UCI) or how to transmit RTD information through uplink MAC control element (UL MAC CE)

3-3) During random access of the terminal, a method of transmitting RTD information through msg3 transmitted from the terminal to the base station.

Meanwhile, in the present disclosure, the target TRP (e.g., the second TRP 310b), which is the object of RTD measurement, can be recognized/confirmed using the following methods 4-1) and 4-2).

4-1) If the target TRP has a different PCI than the serving TRP, how to classify the target TRP based on the PCI (similar to the measurement reporting target based on the PCI)

4-2) If the target TRP has the same PCI as the serving TRP,

4-2-1) A method of distinguishing target TRP and serving TRP by assigning different SSB indexes. Here, the SSB index used by each TRP is allocated so that it does not overlap. For example, in FR1 (frequency range 1) of the NR standard, up to 8 SSBs (index = 0, ..., 7) can be assigned, the serving TRP uses index = 0, ..., 3, and the target TRP How to use index = 4, ..., 7

4-2-2) If the SSB indices assigned to the target TRP and serving TRP overlap, for example, in FR1, up to 8 SSBs (index = 0, ..., 7) can be assigned, and the serving TRP can be assigned If index = 0, ..., 3 is used, and the target TRP uses index = 0, ..., 3, in this case, a method to distinguish the TRP is needed, as shown in 4-2-2-1 below) , 4-2-2-2) method can be supported.

4-2-2-1) A method that includes information (e.g., index) that can distinguish TRPs within the MIB (via PBCH), where the number of bits can be determined depending on the number of TRPs that can be connected to a base station with the same PCI, When this method is used, when generating PSS/SSS sequences in SSB, the sequence is generated based on the above information (e.g., index)

4-2-2-2) A method of distinguishing TRPs by different resource locations in the frequency/time domain of SSB, where the absoluteFrequencySSB IE of the following [Table 3] is used in the RRC information in the frequency domain. The location of the SSB is set differently, and in the time domain, the location of the SSB is determined using ssb-periodicityServingCell IE (i.e., ssb-periodicityServingCell ENUMERATED {ms5, ms10, ms20, ms40, ms80, ms160, spare2, spare1} in the RRC information. set differently

[Table 3]

FIG. 4 is a diagram showing a method performed in a terminal in the embodiment of FIG. 3.

In step 401 of FIG. 4, the terminal 320 receives an RRC reset message for measurement reporting related to multiple TRP operations from the first TRP 310a.

In step 402, the terminal 320 receives the first SSB from the first TRP (310a), and in step 403, the terminal 320 receives the second SSB from the second TRP (310b). The first SSB and the second SSB may have the same SSB index as described above, or may have different SSB indexes. Additionally, the first SSB and the second SSB may be received in the same SSB cycle or may be received in different SSB cycles. In addition, the terminal 320 determines the first SSB and the second based on signaling information (RRC information, SIB, MAC CE, L1 signaling information, etc.) received from the first TRP (310a) or the second TRP (310b). SSB can be received, and the second TRP 310b can be recognized/confirmed as a target TRP related to multiple TRP operations.

In step 404, when a measurement report (MR) event is triggered, the terminal 320 can measure/check the RTD based on the reception timing of the first SSB and the second SSB. The RTD can be measured/confirmed using Equation 1 as described above, and RTD information representing the RTD can be configured and transmitted using various methods as described above.

In step 405, the terminal 320 transmits a measurement report message including the RTD information to the first TRP 310a. In step 406, the terminal 320 receives an RRC reconfiguration message for multiple TRPs (i.e., for adding the second TRP 310b) from the first TRP 310a in response to the RTD restriction being satisfied. A response satisfying the RTD limit means a response from the terminal 320 in which the RTD is within a threshold value (eg, CP length).

Figure 5 is a diagram showing a method performed in the first TRP (serving TRP) in the embodiment of Figure 3.

In step 501 of FIG. 5, the first TRP 310a transmits an RRC reset message for measurement reporting to the terminal 320.

In step 502, the first TRP (310a) transmits the first SSB to the terminal (320).

In step 503, the first TRP 310a receives a measurement report message including RTD information based on the reception timing of the first SSB and the second SSB transmitted from the second TRP 310b from the terminal.

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

In step 505, if the RTD associated with the terminal 320 is less than the threshold, the first TRP 310a determines/confirms that the RTD is valid, and determines/confirms that the RTD is valid for multiple TRPs (i.e. for addition of the second TRP 310b). ) An RRC reset message is sent to the terminal 320.

In step 506, if the RTD associated with the terminal 320 is greater than the threshold, the first TRP 310a determines/confirms that the RTD is invalid and does not set multiple TRPs for the terminal 320 ( That is, in this case, the second TRP 310b is not added). If the RTD is equal to the threshold value, it may be determined to be valid or invalid depending on the setting.

FIG. 6 is a flowchart illustrating a base station (TRP)-based RTD measurement reporting method in a wireless communication system supporting multiple TRP operations according to an embodiment of the present disclosure.

In the example of FIG. 6, the multiple TRP operation includes the terminal transmitting an uplink (UL) signal to two or more TRPs. Before the multi-TRP operation is performed, the first TRP 610a, operating as a serving TRP, transmits a measurement request to the second TRP 610b, a neighboring 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 terminal 620, measures the propagation delay, and transmits the measurement result to the first TRP 610a. The first TRP 610a has an RTD defined as the difference between the first propagation delay on the path from the terminal 620 to the first TRP 610a and the second propagation delay on the path from the terminal 620 to the second TRP 620a. Measure/verify, and decide whether to perform (set or not to set) multiple TRP operations based on the RTD. In the example of FIG. 6, when the first TRP 610a determines the multiple TRP operation as described above, the first TRP 610a and the second TRP 620a cooperate to perform the multiple TRP operation in the UL. A basic RTD measurement reporting method was proposed.

In the embodiment of FIG. 6, T _RTD representing the RTD is It can be defined as <Equation 3> below.

<Equation 3>

T _RTD = |First Propagation Delay - Second Propagation Delay|

First propagation delay: propagation delay between the terminal and serving TRP

Second propagation delay: propagation delay between terminal and neighbor TRP

In step 601 of FIG. 6, the first TRP 610a transmits a propagation delay measurement request message to the second TRP 610b for a measurement request related to multiple TRP operations. Here, the propagation delay measurement request message may include a dedicated preamble index that can be used when measuring propagation delay in the path between the terminal 620 and the second TRP 610b. For example, the dedicated preamble index may use at least one of dedicated preamble indexes that can be allocated in a contention free-based random access procedure.

In step 602, the first TRP 610a receives an acknowledgment message for the propagation delay measurement request from the second TRP 610b. The second TRP (610b) checks whether the dedicated preamble index received in step 601 can be used in the second TRP (610b), and informs the first TRP (610a) whether it can be used through the confirmation response message in step 602. You can respond.

In step 603, if the dedicated preamble index is available in the second TRP 610b, the first TRP 610a transmits an RRC reset message for allocation of a dedicated preamble corresponding to the dedicated preamble index to the terminal 620. do. In step 604, the first TRP 610a receives an RRC reset complete message from the terminal 620 to which the dedicated preamble is assigned.

Afterwards, in step 605, the second TRP 610b receives the PRACH preamble corresponding to the dedicated preamble index from the terminal 620. The PRACH preamble is transmitted, for example, via msg.1 in the random access procedure. At this time, since the second TRP 610b has confirmed the dedicated preamble index in steps 601 and 602, it can recognize that the PRACH preamble is not for random access but for measuring propagation delay for multiple TRP operations.

In step 606, the second TRP (620b) measures the propagation delay (i.e., second propagation delay) of the PRACH preamble in the path from the terminal 620 to the second TRP (620a), and in step 607, the second TRP (620b) Transmits a response message (for example, a random access response (RAR), msg.2 in a random access procedure) to the terminal 620 in response to reception of the PRACH preamble.

In step 608, the first TRP (610a) receives a report message including the measurement result of the second propagation delay from the second TRP (620b), and in step 609, sends a response message to the second TRP (620b) to the report message. send.

In step 610, the first TRP 610a defines the difference between the first propagation delay on the path from the terminal 620 to the first TRP 610a and the second propagation delay on the path from the terminal 620 to the second TRP 620a. Measure/check the RTD and determine/check whether the RTD satisfies the RTD limits. Since the first TRP 610a is the serving TRP of the terminal 620, the first TRP 610a can measure/check the first propagation delay. In step 610, the first TRP 610a may determine whether the RTD limit is satisfied based on whether the RTD is within a threshold value. In the example of FIG. 6, the threshold value may use the CP length as in the example of FIG. 3, or it may be possible to use a preset value to prevent performance degradation due to cross-link interference in UL.

In step 611, if the RTD is less than the threshold, the first TRP 610a determines/confirms that the RTD is valid and sends an RRC reset message for multiple TRPs (i.e. for addition of the second TRP 610b). Transmitted to terminal 620.

If the RTD is greater than the threshold in step 612, the first TRP 610a determines/confirms that the RTD is invalid and does not set multiple TRPs for the terminal 620 (i.e. in this case, the second TRP 610a TRP (610b) is not added).

Therefore, according to the above-described embodiment of FIG. 3, before the multi-TRP operation is performed, the serving TRP measures/checks the RTD between the multiple TRPs, and if the RTD is greater than a set threshold, the UL due to cross-link interference To prevent performance degradation, multiple TRP operations can be prevented. If the RTD is less than a predetermined threshold, the serving TRP can stably perform multiple TRP operations to receive UL signals from the terminal in cooperation with neighboring TRPs.

Meanwhile, in the embodiment of FIG. 6, when the first TRP (610a) and the second TRP (620b) are connected to the same base station (gNB) (or distributed unit (DU)), steps 601, 602, 607, and 608 in FIG. Since the operations may be processed through the same base station (gNB), in this case, the procedure for transmitting and receiving corresponding messages between the first TRP 610a and the second TRP 620b can be omitted.

Meanwhile, in the example of FIG. 6, the RTD can be expressed, for example, using a mapping index for each RTD range (e.g., Timing advanced in TS 38.211).

In addition, the target to which the first TRP 610a transmits the propagation delay measurement request message in step 601 of FIG. 6 can be determined according to the following methods 5-1) and 5-2).

5-1) How to transmit unicast to a specific TRP

5-2) Method of broadcasting to multiple TRPs

Additionally, the method of 5-2) above can also be used when selecting UE-based multiple serving TRPs (for example, it can also be applied to UDN (ultra-dense network), cell-free networks, etc.).

In addition, in step 601 of FIG. 6, the propagation delay measurement request message may include at least one piece of RACH-related information such as a dedicated preamble index and PRACH format (i.e., rach-ConfigCommon setup IE as shown in Table 4 below), , In step 602, the acknowledgment response message for the propagation delay measurement request may include at least one of RACH occasion (RO) mapping settings and SSB bit information. In addition, in step 605 of FIG. 6, the terminal 620 and the second TRP 610b can recognize that the PRACH preamble transmitted/received using the dedicated preamble index is for propagation delay measurement purposes, not random access purposes. . In step 607, a response message (RAR) is sent to the terminal 620 so that the PRACH preamble is not retransmitted, and the terminal 620 does not perform any additional operation after receiving the response message (RAR). No. In addition, the report message including the measurement result of the second propagation delay in step 608 of FIG. 6 may include information such as a dedicated preamble index, a propagation delay value, and an SSB index mapped to the RACH occasion (RO), which are the measurement targets of the propagation delay. You can. The information elements (IE) in [Table 4] below can refer to TS 38.331.

[Table 4]

FIG. 7 is a diagram showing a method performed in a terminal in the embodiment of FIG. 6.

In step 701 of FIG. 7, the terminal 620 receives an RRC reconfiguration message for dedicated preamble allocation from the first TRP 610a. The RRC reset message may include an index of a dedicated preamble that can be used when measuring propagation delay in the path between the terminal 620 and the second TRP 610b.

In step 702, the terminal 620 to which the dedicated preamble is assigned transmits an RRC reset completion message to the first TRP 610a.

In step 703, the terminal 620 transmits a PRACH preamble corresponding to the dedicated preamble index to the second TRP 610b.

In step 704, the terminal 620 receives a response message (for example, a random access response (RAR), msg.2 in the random access procedure) to the transmission of the PRACH preamble from the second TRP 610b.

Afterwards, in step 705, the terminal 620 sends an RRC for multiple TRPs (i.e. for adding the second TRP 610b) from the first TRP 610a in response to the RTD limit being satisfied according to the judgment of the first TRP 610a. Receive a reset message.

FIG. 8 is a diagram showing a method performed in the first TRP (serving TRP) in the embodiment of FIG. 6.

In step 801 of FIG. 8, the first TRP 610a transmits a propagation delay measurement request message to the second TRP 610b. The propagation delay measurement request message may include a dedicated preamble index that can be used when measuring propagation delay in the path between the terminal 620 and the second TRP 610b.

In step 802, the first TRP 610a receives an acknowledgment message for the propagation delay measurement request from the second TRP 610b. The acknowledgment message may include information indicating whether the dedicated preamble index is available in the second TRP 610b.

In step 803, the first TRP 610a transmits an RRC reconfiguration message for dedicated preamble allocation to the terminal 620. The RRC reset message may include the dedicated preamble index. In step 804, the first TRP 610a receives an RRC reset complete message from the terminal 620 to which the dedicated preamble is assigned.

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

In step 806, the first TRP 610a transmits a response message to the report message including the propagation delay measurement result to the second TRP 610b.

In step 807, the first TRP 610a determines the difference between the first propagation delay on the path from the terminal 620 to the first TRP 610a and the second propagation delay on the path from the terminal 620 to the second TRP 620a. Measure/check the defined RTD and determine/check whether the RTD satisfies the RTD limits. Since the first TRP 610a is the serving TRP of the terminal 620, the first TRP 610a can measure/check the first propagation delay.

In step 808, if the RTD is less than the threshold, the first TRP 610a determines/confirms that the RTD is valid and sends an RRC reset message for multiple TRPs (i.e. for addition of the second TRP 610b). is transmitted to the terminal 620.

If the RTD is greater than the threshold in step 809, the first TRP 610a determines/confirms that the RTD is invalid and does not set multiple TRPs for the terminal 620 (i.e. in this case, the second TRP 610a TRP (610b) is not added).

Figure 9 is a diagram showing a method performed in the second TRP (neighboring TRP) in the embodiment of Figure 6.

In step 901 of FIG. 9, the second TRP 610b is a dedicated preamble index that can be used when measuring propagation delay in the path between the terminal 620 and the second TRP 610b from the first TRP 610a. Receive a propagation delay measurement request message containing.

In step 902, the second TRP 610b transmits an acknowledgment message to the first TRP 610a. The second TRP (610b) checks whether the dedicated preamble index received in step 901 can be used in the second TRP (610b), and informs the first TRP (610a) whether it can be used through the confirmation response message in step 902. You can respond.

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

In step 904, the second TRP (610b) measures the propagation delay (i.e., second propagation delay) of the PRACH preamble in the path from the terminal 620 to the second TRP (620a), and in step 905, the second TRP (620b) Transmits a response message (for example, a random access response (RAR), msg.2) in response to reception of the PRACH preamble to the terminal 620.

In step 906, the second TRP (620b) transmits a report message including the measurement result of the second propagation delay to the first TRP (610a), and in step 907, the first TRP (610a) sends a response message to the report message. receives. Afterwards, when the first TRP 610a determines the multi-TRP operation, the second TRP 620a cooperates with the first TRP 610a to perform the multi-TRP operation in the UL.

FIG. 10 is a diagram illustrating an example configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure.

In FIG. 10, the terminal may include a processor 1001, a transceiver 1003, and a memory 1005. The processor 1001, transceiver 1003, and memory 1005 of the terminal may operate according to the method(s) described in the above-described embodiments of FIGS. 1 to 9. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than the aforementioned components. In addition, the processor 1001, transceiver 1003, and memory 1005 may be implemented in the form of at least one chip.

The transceiver 1003 is a general term for a receiver and a transmitter, and can transmit and receive signals to and from a terminal or other network entity through the transceiver 1003. At this time, the transmitted and received signal may include at least one of control information and data. To this end, the transceiver 1003 may include an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, and an RF receiver that amplifies the received signal with low noise and down-converts the frequency. This is only an example of the transceiver 1003, and the components of the transceiver 1003 are not limited to the RF transmitter and RF receiver. Additionally, the transceiver 1003 may receive a signal through a communication method specified in the 3GPP standard, output the signal to the processor 1001, and transmit the signal output from the processor 1001. Additionally, the transceiver 1003 may receive a signal and output it to the processor 1001, and transmit the signal output from the processor 1001 to another network entity through a network. The memory 1005 may store programs and data necessary for operation of the terminal according to at least one of the embodiments of FIGS. 1 to 9. Additionally, the memory 1005 may store control information and/or data included in signals obtained from the terminal. The memory 1005 may be composed of a storage medium such as 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 terminal can operate according to at least one of the embodiments of FIGS. 1 to 9. Processor 1001 may include at least one processor.

FIG. 11 is a diagram illustrating an example configuration of a TRP (or base station) in a wireless communication system according to an embodiment of the present disclosure.

In 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, transceiver 1103, communication interface 1105, and memory 1105 of the TRP may operate according to the method(s) described in the above-described embodiments of FIGS. 1 to 9. However, the components of TRP are not limited to the examples described above. For example, a TRP may include more or fewer components than those described above. In addition, the processor 1101, transceiver 1103, communication interface 1105, and memory 1105 may be implemented in the form of at least one chip.

The transceiver 1103 is a general term for a receiver and a transmitter, and signals can be transmitted and received between a terminal and a wireless network through the transceiver 1003. Additionally, the TRP (or base station) can transmit and receive signals in a wired network or wireless network with another network entity (e.g., another TRP (or base station)) through the communication interface 1105. In this case, the transceiver 1103 or the communication interface The signal transmitted and received through 1105 may include at least one of control information and data. In addition, the transceiver 1103 and the communication interface 1105 receive the signal through the communication method specified in the 3GPP standard and transmit the signal to the processor 1101. ), and the signal output from the processor 1101 can be transmitted to another network entity. The memory 1105 stores programs and data necessary for the operation of the TRP according to at least one of the embodiments of FIGS. 1 to 9. In addition, the memory 1105 may store control information and/or data included in signals obtained from a network entity. The memory 1105 may include ROM, RAM, hard disk, and CD- It may be composed of a storage medium or a combination of storage media such as ROM, DVD, etc. The processor 1101 may control a series of processes so that the TRP can operate according to at least one of the embodiments of FIGS. 1 to 9. .The processor 1001 may include at least one processor.

Methods according to embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software. When the processors 1001 and 1101 are implemented as software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium are configured to be executable by one or more processors in an electronic device (configured for execution). One or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

These programs (software modules, software) may include random access memory, non-volatile memory, including flash memory, read only memory (ROM), and electrically erasable programmable ROM. (electrically erasable programmable read only memory, EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile discs (DVDs), or other types of disk storage. It can be stored in an optical storage device or magnetic cassette. Alternatively, it may be stored in a memory consisting of a combination of some or all of these. Additionally, multiple configuration memories may be included. The program is accessed 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 combination thereof. It may be stored in an attachable storage device that can be accessed. This storage device can be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to the device performing an embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, elements included in the disclosure are expressed in singular or plural numbers depending on the specific embodiment presented. However, singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components, and even components expressed in plural may be composed of singular or singular. Even expressed components may be composed of plural elements.

Meanwhile, in the detailed description of the present disclosure, specific embodiments have been described, but of course, various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the patent claims described later, but also by the scope of this patent claim and equivalents.

Claims (20)

In a method for a terminal to support multiple transmission reception point (TRP) operations in a wireless communication system,
A process of receiving a first SSB (synchronization signal block) from the first TRP, which is the serving TRP of the terminal;
Receiving a second SSB from a second TRP, which is a neighboring TRP of the first TRP;
Checking a reception timing difference (RTD) between the first SSB and the second SSB; and
When a measurement report event is triggered, a method comprising transmitting a measurement report message including information indicating the RTD to the first TRP.
According to claim 1,
In response to the RTD limit being satisfied, the method further includes receiving, from the first TRP, a radio resource control (RRC) reset message adding the second TRP for the multi-TRP operation.
According to claim 2,
If the RTD is less than the threshold, the RTD limit is satisfied, and if the RTD is greater than the threshold, the second TRP is not added.
According to claim 1,
A method in which at least one of the transmission period and SSB index of the first SSB and the second SSB is the same.
According to claim 1,
The information representing the RTD is:
RTD corresponding to the SSB index with the strongest received signal strength,
an average RTD for a plurality of SSB indices, and
A method comprising at least one of RTDs for a set number of SSB indices selected based on signal strength or signal quality.
In a terminal in a wireless communication system,
transceiver; and
Receiving a first synchronization signal block (SSB) from a first TRP, which is a serving transmission reception point (TRP) of the terminal, through the transceiver,
Receiving a second SSB from a second TRP, which is a neighboring TRP of the first TRP, through the transceiver,
Check the reception timing difference (RTD) between the first SSB and the second SSB,
A terminal comprising a processor configured to transmit, when a measurement report event is triggered, a measurement report message including information indicating the RTD to the first TRP through the transceiver.
According to claim 6,
In response to the RTD restriction being satisfied, the processor is further configured to receive a radio resource control (RRC) reset message from the first TRP through the transceiver to add the second TRP for the multi-TRP operation.
According to claim 7,
If the RTD is less than the threshold, the RTD limit is satisfied, and if the RTD is greater than the threshold, the second TRP is not added.
According to claim 6,
A terminal in which at least one of the transmission period and SSB index of the first SSB and the second SSB is the same.
According to claim 6,
The information representing the RTD is:
RTD corresponding to the SSB index with the strongest received signal strength,
an average RTD for a plurality of SSB indices, and
A terminal including at least one of RTDs for a set number of SSB indices selected based on signal strength or signal quality.
In a method for a serving TRP (transmission reception point) of a terminal to support multiple TRP operations in a wireless communication system,
Transmitting a propagation delay measurement request message including information on a dedicated preamble that can be used when measuring propagation delay in a path between the terminal and the neighboring TRP to a neighboring TRP of the serving TRP;
The process of allocating the dedicated preamble to the terminal;
Receiving a report message including a propagation delay measurement result of the PRACH preamble from the neighboring TRP that has received the PRACH (physical random access channel) preamble from the terminal; and
A method comprising determining whether to perform a multiple TRP operation for the terminal based on the received propagation delay measurement result.
According to claim 11,
The determining process includes: checking a first propagation delay on a path from the terminal to the serving TRP;
Confirming a second propagation delay on a path from the terminal to the neighboring TRP using the received propagation delay measurement result; and
A method comprising checking a reception timing difference (RTD) between the first propagation delay and the second propagation delay.
According to claim 12,
If the RTD is less than a threshold, determining that the RTD is valid; and
The method further includes transmitting a radio resource control (RRC) reconfiguration message adding the neighboring TRP to the terminal for the multi-TRP operation.
According to claim 13,
If the RTD is greater than the threshold, determining that the RTD is invalid; and
The method further includes determining not to perform the multiple TRP operation.
According to claim 11,
The dedicated preamble is used to measure propagation delay related to setting up the multi-TRP operation.
In a serving TRP (transmission reception point) in a wireless communication system,
transceiver;
communication interface; and
Through the communication interface, transmitting a propagation delay measurement request message containing information about a dedicated preamble that can be used when measuring propagation delay in a path between the terminal and the neighboring TRP to a neighboring TRP of the serving TRP,
Allocating the dedicated preamble to the terminal through the transceiver,
Through the communication interface, receive a report message including a propagation delay measurement result of the PRACH preamble from the neighboring TRP that received the PRACH (physical random access channel) preamble from the terminal,
A serving TRP comprising a processor configured to determine whether to perform a multiple TRP operation for the terminal based on the received propagation delay measurement result.
According to claim 16,
The processor checks the first propagation delay on the path from the terminal to the serving TRP,
Confirming the second propagation delay in the path from the terminal to the neighboring TRP using the received propagation delay measurement result,
A serving TRP further configured to determine a reception timing difference (RTD) between the first propagation delay and the second propagation delay.
According to claim 17,
If the RTD is less than the threshold, the processor determines that the RTD is valid, and sends a radio resource control (RRC) reset message to the terminal through the transceiver to add the neighbor TRP for the multi-TRP operation. A serving TRP further configured to transmit.
According to claim 18,
The processor is further configured to, if the RTD is greater than the threshold, determine that the RTD is invalid and not perform the multiple TRP operation.
According to claim 16,
The dedicated preamble is a serving TRP used to measure propagation delay related to setting up the multi-TRP operation.

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