Method and apparatus for sidelink localization in a wireless communication system

Abstract

A method performed by a terminal in a wireless communication system is provided. The method includes obtaining information about transmission parameters associated with the SL positioning reference signal, identifying a resource pool associated with the SL positioning reference signal, performing a measurement based on the resource pool associated with the SL positioning reference signal, and determining at least one transmission parameter associated with the SL positioning reference signal based on the measurement and the information about the transmission parameter. The transmission parameter includes at least one of a comb size associated with the SL positioning reference signal and a number of symbols for the SL positioning reference signal in the time slot.

Description

Technical Field

[0001] The present disclosure relates generally to a wireless communication system, and more particularly, to a method and apparatus for performing positioning (eg, position measurement) through a sidelink (SL). Background Art

[0002] The fifth generation (5G) mobile communication technology defines a wide frequency band so that high transmission rates and new services are possible, and can be achieved in "sub-6 gigahertz (GHz)" frequency bands such as 3.5 GHz, and can also be achieved in "above 6 GHz" frequency bands, which can be called millimeter waves, including 28 GHz and 39 GHz.

[0003] In addition, consideration has been given to implementing the 6th generation (6G) mobile communication technology (e.g., referred to as a "super 5G system") in the terahertz (THz) frequency band (e.g., the 95 GHz to 3 THz band) in order to achieve a transmission rate fifty times faster than that of the 5G mobile communication technology and an ultra-low latency one-tenth of that of the 5G mobile communication technology.

[0004] Since the initial development of 5G mobile communication technology, in order to support services and meet performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC), and massive machine type communications (mMTC), there has been ongoing standardization on beamforming and massive multiple-input multiple-output (MIMO) for mitigating radio wave path loss in mmWave and increasing radio wave transmission distance, support for dynamic operation of parameter sets (e.g., operating multiple subcarrier spacings (SCSs)) and time slot formats for efficient utilization of mmWave resources, initial access technology for supporting multi-beam transmission and broadband, definition and operation of bandwidth parts (BWPs), new channel coding methods such as low-density parity-check (LDPC) codes for large amounts of data transmission and polar codes for highly reliable transmission of control information, layer 2 (L2) pre-processing, and network slicing for providing dedicated networks tailored for specific services.

[0005] Currently, in consideration of the services supported by 5G mobile communication technology, discussions are underway on improvements and performance enhancements to initial 5G mobile communication technology, and there is already physical layer standardization on technologies such as Vehicle-to-Everything (V2X) for assisting driving determination of autonomous vehicles based on information about the location and status of a vehicle sent by the vehicle and for enhancing user convenience, New Radio Unlicensed (NR-U) for system operations designed to comply with various regulatory-related requirements in unlicensed bands, NR User Equipment (UE) power saving, Non-Terrestrial Networks (NTNs) as UE-satellite direct communications for providing coverage in areas where communication with terrestrial networks is impossible, and positioning.

[0006] In terms of air interface architecture / protocol, there is also ongoing standardization of technologies such as the Industrial Internet of Things (IIoT) for supporting new services through interworking and integration with other industries, Integrated Access and Backhaul (IAB) for providing nodes for network service area expansion by supporting wireless backhaul links and access links in an integrated manner, mobility enhancements including conditional handover and dual active protocol stack (DAPS) handover, and two-step random access (NR two-step RACH) for simplifying the random access process. In terms of system architecture / services, standardization is also ongoing on the following items: 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.

[0007] As 5G mobile communication systems are commercialized, the number of devices that will be connected to the communication network is expected to increase exponentially, and accordingly it is expected that enhanced functions and performance of the 5G mobile communication systems and integrated operations of connected devices will be necessary. To this end, new research related to extended reality (XR) is arranged for effectively supporting augmented reality (AR), virtual reality (VR), mixed reality (MR), etc., improving 5G performance and reducing complexity by utilizing artificial intelligence (AI) and machine learning (ML), AI service support, metaverse service support, and drone communication.

[0008] In addition, such development of 5G mobile communication systems will serve as the basis for the development of new waveforms for providing coverage in the terahertz band of 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 orbital angular momentum (OAM), and reconfigurable smart surfaces (RIS), as well as the development of full-duplex technology for improving frequency efficiency of 6G mobile communication technology and improving system networks, AI-based communication technology for achieving system optimization by utilizing satellites and AI from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for realizing services with a complexity level that exceeds the limits of UE operating capabilities by utilizing ultra-high performance communication and computing resources. Summary of the invention

[0009] Technical issues

[0010] The present disclosure has been made to address at least the above-mentioned problems and / or disadvantages and to provide at least the advantages described below.

[0011] An aspect of the present disclosure is to provide a method and apparatus for performing positioning (eg, position measurement) through a SL.

[0012] Another aspect of the present disclosure is to provide a method for performing positioning through SL.

[0013] Another aspect of the present disclosure is to provide a method for performing congestion control when performing positioning through SL.

[0014] Technical Solutions

[0015] According to one aspect of the present disclosure, a method for a terminal in a wireless communication system is provided. The method includes obtaining information about transmission parameters associated with a SL positioning reference signal (PRS), identifying a resource pool associated with the SL PRS, performing measurements based on the resource pool associated with the SL PRS, and determining at least one transmission parameter associated with the SL PRS based on the information about the transmission parameters and the measurements. The transmission parameters include at least one of the number of symbols of the SL PRS in a time slot and a comb size associated with the SLPRS.

[0016] According to another aspect of the present disclosure, a terminal for use in a wireless communication system is provided. The terminal includes a transceiver and a controller, the controller being coupled to the transceiver and configured to obtain information about transmission parameters associated with a SL PRS, identify a resource pool associated with the SL PRS, perform measurements based on the resource pool associated with the SL PRS, and determine at least one transmission parameter associated with the SL PRS based on the information about the transmission parameters and the measurements. The transmission parameters include at least one of the number of symbols of the SL PRS in a time slot and a comb size associated with the SL PRS.

[0017] Beneficial effects

[0018] According to an embodiment of the present disclosure, a terminal can perform positioning (position measurement) through a side link, and the positioning accuracy can be improved.

[0019] In addition, according to an embodiment of the present disclosure, the terminal can perform congestion control when performing positioning through a sidelink.

[0020] Other aspects, advantages, and salient features of the present disclosure will become apparent to those skilled in the art from the following detailed description which, in conjunction with the accompanying drawings, discloses various embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0022] Figure 1A shows a SL communication scenario in a wireless communication system according to an embodiment;

[0023] Figure 1B shows a SL communication scenario in a wireless communication system according to an embodiment;

[0024] Figure 1C shows a SL communication scenario in a wireless communication system according to an embodiment;

[0025] Figure 1D shows a SL communication scenario in a wireless communication system according to an embodiment;

[0026] Figure 2 A communication method performed by a SL according to an embodiment is shown;

[0027] Figure 3 shows a resource pool defined as a set of resources in the time domain and the frequency domain for transmission and reception of a SL according to an embodiment;

[0028] Figure 4 Calculation of the location of a terminal by SL according to an embodiment is shown;

[0029] Figure 5 Calculation of the location of a terminal by SL according to an embodiment is shown;

[0030] Figure 6 Calculation of the location of a terminal by SL according to an embodiment is shown;

[0031] Figure 7 It is shown that positioning is performed using a round trip time (RTT) method according to an embodiment;

[0032] Figure 8 shows a pattern of a SL PRS (S-PRS) based on a downlink (DL) PRS according to an embodiment;

[0033] Fig. 9 shows a pattern of an S-PRS based on an uplink (UL) PRS according to an embodiment;

[0034] Fig.10 A method for transmitting a SL positioning signal in a dedicated resource region according to an embodiment is shown, the dedicated resource region being distinguished from a resource region for transmitting a physical SL shared channel (PSSCH);

[0035] Fig.11 It is shown that relevant parameters are applied when selecting and allocating transmission resources of S-PRS according to an embodiment of the present disclosure.

[0036] Fig.12 shows a time slot for sending a SL positioning signal according to an embodiment;

[0037] Fig.13A method for determining transmission parameters according to congestion control when sending a SL positioning signal according to an embodiment is shown;

[0038] Fig.14 is a flowchart illustrating the operation of a terminal according to an embodiment;

[0039] Fig.15 shows a terminal according to an embodiment; and

[0040] Fig.16 A base station (BS) according to an embodiment is shown. DETAILED DESCRIPTION

[0041] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0042] When describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present disclosure belongs and are not directly related to the present disclosure will be omitted. This is to convey the subject matter of the present disclosure more clearly without obscuring it by omitting unnecessary descriptions.

[0043] For the same reason, some elements are exaggerated, omitted or schematically shown in the drawings. In addition, the depicted size of each element does not fully reflect the actual size. In the drawings, the same or corresponding elements are given the same reference numerals.

[0044] The various advantages and features of the present disclosure and the ways to achieve them will become apparent through the embodiments described below with reference to the accompanying drawings. However, the present disclosure can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. The present disclosure is limited only by the scope of the appended claims.

[0045] Like reference numerals may refer to like elements throughout the specification.

[0046] Each frame of the flowchart diagram and the combination of frames in the flowchart diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate a device for realizing the function specified in the flowchart frame. These computer program instructions can also be stored in a computer-usable or computer-readable memory, which can instruct the computer or other programmable data processing device to act in a specific way, so that the instructions stored in the computer-usable or computer-readable memory produce a product including an instruction device that realizes the function specified in the flowchart frame. The computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are performed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for realizing the function specified in the flowchart frame.

[0047] In addition, each frame of the flowchart diagram can represent a module, a fragment or a part of a code, which includes one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions pointed out in the frame can occur out of order. For example, two frames shown in succession can actually be performed substantially simultaneously, or these frames can sometimes be performed in reverse order, depending on the functions involved.

[0048] As used herein, the term "unit" may refer to a software element or a hardware element that performs a predetermined function, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, the term "unit" does not always have a meaning that is limited to software or hardware. "Unit" may be constructed to be stored in an addressable storage medium or to execute one or more processors. Therefore, "unit" includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays and variables. The function provided by elements and units may be combined into the function of a smaller number of elements and units, or may be separated into the function of a larger number of elements and units. In addition, elements and units may be implemented as one or more central processing units (CPUs) in an operating device or a secure multimedia card. In addition, in an embodiment, "unit" may include one or more processors.

[0049] According to the 5G mobile communication standard specified by the 3rd Generation Partnership Project (3GPP) as a mobile communication standardization organization, this document will focus on the radio access network (i.e., NR) and the packet core (i.e., 5G system, 5G core network or next generation (NG) core) to describe the embodiments of the present disclosure. However, as will be apparent to those skilled in the art, the subject matter of the present disclosure may also be applied to other communication systems with similar technical backgrounds by slight modifications without departing from the scope of the present disclosure.

[0050] In the 5G system, a network data collection and analysis function (NWDAF) as a network function (NF) that collects, analyzes, and provides data in a 5G network may be defined to support network automation. The NWDAF may collect information from the 5G network, store and analyze the collected information, and provide the analysis results to an unspecified NF. The analysis results may be used independently in each NF.

[0051] For ease of description, some terms and names defined in 3GPP standards (e.g., 5G, NR, Long Term Evolution (LTE) or similar system standards) will be used. However, the present disclosure is not limited to these terms and names and can also be applied to any other system conforming to any other standard.

[0052] In addition, for the sake of convenience, terms for identifying access nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc. are illustratively used. Therefore, the present disclosure is not limited to the terms used below, and other terms relating to subjects with equivalent technical meanings may be used.

[0053] In order to meet the increased demand for wireless data services since the deployment of the fourth generation (4G) communication system, efforts have been made to develop improved 5G communication systems (e.g., NR). In order to achieve higher data rates, 5G communication systems are designed to enable resources in extremely high frequency (millimeter wave) bands (e.g., 28 GHz bands). In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive MIMO, FD-MIMO, array antennas, analog beamforming, massive antenna technology, etc. have been discussed and adopted in 5G communication systems. In addition, unlike LTE, 5G communication systems support various SCSs such as 15kHz, 30kHz, 60kHz, and 120kHz, use polarization coding for physical control channels, and use LDPC for physical data channels. In addition, cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) and discrete Fourier transform-spread-OFDM (DFT-S-OFDM) are used as waveforms for UL transmission. LTE supports hybrid automatic repeat request (HARQ) retransmission in units of transport blocks (TBs), while 5G may additionally support HARQ retransmission based on code block groups (CBGs), in which multiple code blocks (CBs) are bundled.

[0054] In addition, for system network improvements in 5G communication systems, technical development has been carried out for evolved small cells, advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, V2X networks, collaborative communications, coordinated multi-point (CoMP), reception interference cancellation, etc.

[0055] The Internet is now evolving into the Internet of Things (IoT), in which distributed components (i.e., things) exchange and process information. The Internet of Everything (IoE), which is a combination of IoT technology and big data processing technology through connection with a cloud server, has also emerged. Since IoT implementation requires technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology, sensor networks for machine-to-machine connection, machine-to-machine (M2M) communication, machine type communication (MTC), etc. have recently been studied.

[0056] Such an IoT environment can provide intelligent Internet technology services by collecting and analyzing data generated between connected things. Through the integration and combination between existing information technology and various industries, IoT can be applied to various fields, including smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services.

[0057] Various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies for sensor networks, M2M communications, and MTC have been implemented by technologies for beamforming, MIMO, and array antennas corresponding to 5G communication technologies. As a big data processing technology as described above, the application of cloud RAN will be an example of the fusion between 5G technology and IoT technology.

[0058] As described above, a plurality of services may be provided to a user in a communication system, and in order to provide the plurality of services to the user, a method of providing each service in the same time interval according to characteristics of each service and an apparatus using the method are required.

[0059] Various services provided by 5G communication systems are being studied, one of which is a service that meets the requirements of low latency and high reliability.

[0060] Furthermore, the demand for location-based services (LBS) and mobile services, driven primarily by emergency services and commercial applications, is growing rapidly.

[0061] Specifically, in the communication using SL, the NR SL system supports unicast communication, groupcast (or multicast) communication and broadcast communication between terminals. In addition, unlike LTE SL, which is designed to send and receive basic safety information required for driving vehicles on the road, NR SL is designed to provide more advanced services such as platooning, advanced driving, extended sensors and remote driving.

[0062] Specifically, in NR SL, positioning (or position measurement) can be performed through SL between terminals. In other words, a method of measuring the position of a terminal by using a positioning signal sent through SL can be considered. Conventionally, when the terminal is within the coverage of the BS, a method of measuring the position of the terminal by using a positioning signal sent through DL and UL between the terminal and the BS is feasible. However, by introducing SL positioning, the position of the terminal can be measured even when the terminal is out of the coverage of the BS.

[0063] Specifically, SL positioning can be performed by signal transmission. Examples of signals that can be used for SL positioning are provided below. However, the scope of the present disclosure is not limited to the following signals, and the present disclosure can be applied to other signals used when positioning is performed by SL.

[0064] -S-PRS

[0065] -Measurement report

[0066] - Location information transmission

[0067] The S-PRS is a signal transmitted by a terminal for positioning measurement. A terminal receiving the S-PRS may perform positioning measurement using the signal, and a measurement method using the S-PRS may vary according to a positioning method.

[0068] A terminal that has measured positioning may send corresponding measurement information to another terminal, a BS, or a location server (LS). The sent measurement may be referred to as a measurement report.

[0069] Location information transmission may refer to information sent to indicate the known location of a terminal to another terminal. Using the corresponding information, the terminal can measure relative and absolute positions. In addition to the above information, additional information required to perform SL positioning may be exchanged between terminals. For example, the reliability of the known location information may be included.

[0070] The terminal can allocate resources for sending such a positioning signal and send the signal in the corresponding resources. In addition, considering the congestion level of SL transmission, the terminal can control whether to send the signal and related transmission parameters. Existing congestion control is defined for PSSCH. However, the congestion control for positioning signals may be different from the congestion control for PSSCH transmission. For example, the positioning signal may be sent in the same resources as the PSSCH transmission resources, but may be sent in dedicated resources for positioning signal transmission to prevent conflicts with data transmission. In addition, the S-PRS can be transmitted at a time and frequency different from the time and frequency in the PSSCH transmission, and therefore, the parameters for S-PRS transmission can be defined differently from the parameters in the PSSCH transmission.

[0071] According to an embodiment of the present disclosure, a method and apparatus for performing congestion control when measuring the position (positioning) of a UE in a SL are provided. When a positioning signal is transmitted, collision of the positioning signal can be prevented through congestion control, and thus positioning accuracy can be improved.

[0072] Figures 1A to 1D A SL communication scenario in a wireless communication system according to an embodiment is shown.

[0073] Specifically, Figure 1A An example of a convergence (IC) scenario is shown in which all terminals (eg, UE-1 and UE-2) communicating through the SL are located within the coverage of the BS.

[0074] refer to Figure 1A , all terminals can receive data and control information from the BS through DL, or send data and control information to the BS through UL. In this case, the data and control information can be used for SL communication. The data and control information can also be used for general cellular communication. In addition, the terminal can send / receive data and control information for corresponding communication through SL.

[0075] Figure 1B An example of a partial coverage (PC) scenario is shown, in which some terminals (eg, UE-1) are located within the coverage of the BS and some terminals (eg, UE-2) are located outside the coverage of the BS.

[0076] refer to Figure 1B , a terminal (e.g., UE-1) within the coverage of the BS can receive data and control information from the BS through DL, or send data and control information to the BS through UL. A terminal (e.g., UE-2) outside the coverage of the BS cannot receive data and control information from the BS through DL, and cannot send data and control to the BS through UL. The terminal (e.g., UE-2) can send / receive data and control information for corresponding communication through SL.

[0077] Figure 1C An example of an out-of-coverage (OOC) scenario is shown, where all terminals are outside the coverage of the BS.

[0078] refer to Figure 1C , the terminals (e.g., UE-1 and UE-2) cannot receive data and control information from the BS through DL, and cannot send data and control information to the BS through UL. The terminals (e.g., UE-1 and UE-2) can send / receive data and control information through SL.

[0079] Figure 1D An example of a scenario in which terminals (eg, UE-1, UE-2) located in different cells perform SL communication is shown.

[0080] refer to Figure 1D , the terminals (e.g., UE-1, UE-2) access different BSs (i.e., Radio Resource Control (RRC) connected state) or stay on the BS (i.e., RRC connection released state or RRC idle state). In this case, the first terminal (e.g., UE-1) may be a transmitting terminal, and the second terminal (e.g., UE-2) may be a receiving terminal. Alternatively, the first terminal (e.g., UE-1) may be a receiving terminal in the SL, and the second terminal (e.g., UE-2) may be a transmitting terminal.

[0081] A first terminal (e.g., UE-1) may receive a system information block (SIB) from a BS accessed by the first terminal (or where the first terminal resides), and a second terminal (e.g., UE-2) may receive the SIB from another BS accessed by the second terminal (or where the second terminal resides). In this case, as the SIB, an existing SIB or a separately defined SIB for SL communication may be used. In addition, the SIB information received by the first UE (e.g., UE-1) and the SIB information received by the second terminal (e.g., UE-2) may be different from each other. Therefore, in order to perform SL communication between terminals (e.g., UE-1, UE-2) located in different cells, the information may be unified, or a method for interpreting the SIB information sent from each other cell by signaling about the information may be additionally required.

[0082] Although for ease of description, Figures 1A to 1D A SL system including two terminals (e.g., UE-1 and UE-2) is shown, but the present disclosure is not limited thereto, and communication can be performed between more terminals. In addition, the interface (UL and DL) between the BS and the terminal can be referred to as a Uu interface, and the SL between the terminals can be referred to as a PC5 interface. Therefore, these terms can be used interchangeably in the present disclosure.

[0083] In this document, a terminal may refer to a general terminal and a terminal supporting V2X. For example, a terminal may refer to a pedestrian's mobile phone (e.g., a smart phone), or a terminal may include a vehicle supporting vehicle-to-vehicle (V2V) communication, a vehicle supporting vehicle-to-pedestrian (V2P) communication, a vehicle supporting vehicle-to-network (V2N) communication, or a vehicle supporting vehicle-to-infrastructure (V2I) communication. Alternatively, a terminal may include a roadside unit (RSU) with terminal functions, an RSU with BS functions, or an RSU with some BS functions and some terminal functions.

[0084] In addition, the BS may support both V2X communication and general cellular communication or only V2X communication. For example, the BS may be a 5G BS (gNB), a 4G BS (eNB), or an RSU. Therefore, the BS may be referred to as an RSU.

[0085] Figure 2 A communication method performed by the SL according to an embodiment is shown.

[0086] refer to Figure 2For unicast communication, UE-1 201 (e.g., transmitting (TX) UE) and UE-2 202 (e.g., receiving (RX) UE) can communicate in a one-to-one manner. In SL, capability information and configuration information can be exchanged between terminals through PC5-RRC defined in a unicast link between terminals. In addition, configuration information can be exchanged through SL media access control elements (MAC CEs) defined in a unicast link between terminals.

[0087] For multicast communication, TX UE and RX UE can communicate in a one-to-many manner. Figure 2 , UE-1 211, UE-2 212, and UE-3 213 may form one group (Group A) and perform multicast communication, and UE-4 214, UE-5 215, UE-6 216, and UE-7 217 may form another group (Group B) and perform multicast communication. Each UE may perform multicast communication only within the group to which the UE belongs, and communication between different groups may be performed by unicast, multicast, or broadcast communication. Although Figure 2 The multicast communication in FIG. 1 shows that two groups (Group A and Group B) are formed, but the scope of the present disclosure is not limited thereto.

[0088] Although not in Figure 2 , but the UE can perform broadcast communication in the SL. For broadcast communication, all UEs receive data and control information sent by the transmitting UE through the SL. Figure 2 , it is assumed that UE-1 211 is a TX UE for broadcasting, and UE-2 212, UE-3 213, UE-4 214, UE-5 215, UE-6 216, and UE-7 217 receive data and control information transmitted by UE-1 211.

[0089] In NR V2X, unlike LTE V2X, it is possible to consider supporting a type in which a vehicle UE sends data to only one specific node (or UE) by unicast and another type in which a vehicle UE sends data to multiple specific nodes (or UEs) by multicast. For example, unicast and multicast technologies can be usefully used in service scenarios such as platooning, which is a technology in which two or more vehicles are connected through a network and move in a cluster. Specifically, unicast communication can be used by a leader node in a group connected by platooning to control one specific node, and multicast communication can be used to simultaneously control a group including multiple specific nodes.

[0090] Figure 3 A resource pool defined as a set of resources in the time domain and the frequency domain for transmission and reception of a SL according to an embodiment is shown.

[0091] For example, a resource allocation unit (e.g., resource granularity) on the time axis within a resource pool may be a time slot. A resource allocation unit on the frequency axis within a resource pool may be a subchannel including one or more physical resource blocks (PRBs). Although the present disclosure includes examples of discontinuous allocation of resource pools on the time axis, resource pools may be continuously allocated on the time axis. In addition, although the present disclosure includes examples of continuous allocation of resource pools on the frequency axis, the present disclosure does not exclude methods of discontinuous allocation of resource pools on the frequency axis.

[0092] refer to Figure 3 , the resource pool is allocated discontinuously on the time axis (301). The resource allocation unit (granularity) on the time axis may be a time slot unit, and the SL time slot may be defined in the time slot used for UL. Specifically, the position and length of the symbol used as SL in one time slot may be configured as SL BWP information (e.g., SL-BWP-Generic). Therefore, in the time slot used for UL, the time slot for which the length of the symbol configured as SL is not guaranteed may not be the SL time slot. In addition, the time slot belonging to the resource pool may be excluded from the time slot to which the SL synchronization signal block (S-SSB) is transmitted.

[0093] refer to Figure 3 In 301, a set of time slots other than the time slots described above that can be used as SLs in the time domain can be determined. SL time slots belonging to a resource pool can be (pre-)configured with resource pool information via a bitmap. Figure 3 In 302, the set of SL time slots belonging to the resource pool in time is logically mapped and shown as

[0094] In this document, (pre) configuration may refer to configuration information that is preconfigured and pre-stored in the UE, or may refer to when the UE is configured from the BS in a cell-common manner. The cell-common manner may include UEs in a cell receiving the same information configuration from the BS. In this case, the UE may consider a method of obtaining cell-common information by receiving SL-SIB from the BS. In addition, it may include when the UE is configured in a UE-specific manner after establishing an RRC connection with the BS.

[0095] In this document, UE-specific may be replaced with the term UE-specific, and may include when configuration information having a specific value for each UE is received. In this case, a method in which the UE receives an RRC message from the BS and obtains UE-specific information may be considered. In addition, (pre) configuration may consider a method configured in resource pool information and a method not configured in resource pool information.

[0096] When the (pre) configuration is configured in the resource pool information, except when the UE is configured in a UE-specific manner, after establishing an RRC connection with the BS, all UEs operating in the corresponding resource pool can operate with the common configuration information. However, the method in which the (pre) configuration is not configured in the resource pool information is basically configured independently of the resource pool configuration information. For example, one or more modes can be (pre) configured in a resource pool (e.g., A, B, and C), and the (pre) configuration information independent of the resource pool configuration information can indicate which mode (e.g., A, B, or C) is used in the (pre) configuration mode in the resource pool. In addition, in SL unicast transmission, the (pre) configuration can be configured through PC5-RRC.

[0097] Optionally, a method of (pre)configuration through MAC-CE configuration may also be considered. In the present disclosure, (pre)configuration may be applied to all the above situations.

[0098] refer to Figure 3 In 303, the resource pool can be continuously allocated on the frequency axis. For example, on the frequency axis, the resource allocation can be configured with SL BWP information and can be performed in units of subchannels. A subchannel can be defined as a resource granularity on the frequency axis including one or more PRBs. That is, a subchannel can be defined as an integer multiple of a PRB. In 303, a subchannel includes five consecutive PRBs, and the subchannel size (sizeSubchannel) is the size of five consecutive PRBs. However, Figure 3 It is only an example of the present disclosure, and the size of the subchannel may be configured differently, and one subchannel is generally constituted as continuous PRBs, but is not necessarily configured as continuous PRBs. The subchannel may be a basic unit of resource allocation for PSSCH.

[0099] When resource allocation on the frequency axis is performed in units of subchannels, resources on the frequency axis may be allocated based on a resource block (RB) index indicating a start position of a subchannel in a resource pool (e.g., startRB-Subchannel), information about the number of PRBs in one subchannel (e.g., sizeSubchannel), configuration information about the total number of subchannels (e.g., numSubchannel), etc. In this case, information about startRB-Subchannel, sizeSubchannel, and numSubchannel may be (pre-)configured in the frequency domain resource pool information.

[0100] A method for allocating transmission resources in SL includes: receiving SL transmission resources from a BS when a terminal is within the coverage of the BS. Hereinafter, the method is referred to as Mode 1. In other words, Mode 1 may be a method performed by the BS to allocate resources for SL transmission to RRC-connected terminals in a dedicated scheduling scheme. Mode 1 allows the BS to manage resources of the SL and is effective in interference management and resource pool management.

[0101] Alternatively, the method for allocating transmission resources in the SL includes allocating transmission resources by direct sensing by the terminal in the SL. Hereinafter, this method is referred to as Mode 2. Mode 2 may also be referred to as UE autonomous resource selection. Unlike Mode 1 in which the BS directly participates in resource allocation, in Mode 2, the transmitting terminal autonomously selects resources through a sensing and resource selection process defined based on a (pre)configured resource pool, and sends data through the selected resources.

[0102] When transmission resources are allocated through mode 1 or mode 2, the terminal can send / receive data and control information through SL. Here, the control information may include SL control information (SCI) format 1-A as the first-stage SCI sent through the physical SL control channel (PSCCH). In addition, the control information may include at least one of SCI format 2-A and SCI format 2-B as the second-stage SCI sent through PSSCH.

[0103] Next, a method for positioning using PRS transmitted through DL and UL of a terminal and a BS to measure the position of a terminal is described. In the present disclosure, a positioning method using positioning signals transmitted through DL and UL of a terminal and a BS may be referred to as positioning dependent on a radio access technology (RAT). In addition, other positioning methods may be classified as positioning independent of RAT. Specifically, in the case of an LTE system, as a positioning scheme dependent on RAT, methods such as observed time difference of arrival (OTDOA), UL time difference of arrival (UTDOA), and enhanced cell identification (E-CID) may be used. In the case of an NR system, methods such as DL time difference of arrival (DL-TDOA), DL angle of departure (DL-AOD), multi-RTT, NR E-CID, UL time difference of arrival (UL-TDOA), and UL angle of arrival (UL-AOA) may be used. On the other hand, a positioning scheme independent of RAT may include Assisted Global Navigation Satellite System (A-GNSS), sensors, wireless local area networks (WLAN), and

[0104] The present disclosure provides a RAT-dependent positioning method supported by SL. In the case of an interface between a BS and a terminal (UL and DL, hereinafter referred to as Uu), when the terminal is within the coverage of the BS, RAT-dependent positioning is available. However, note that the RAT-dependent positioning of the SL may not be limited to when the terminal is within the coverage of the BS. In the case of RAT-dependent positioning in Uu, positioning protocols such as the LTE Positioning Protocol (LPP), the LTE Positioning Protocol Annex (LPPa), and the NR Positioning Protocol Annex (NRPPa) may be used. LPP is considered to be a positioning protocol defined between the terminal and the LS, and LPPa and NRPPa are considered to be protocols defined between the BS and the LS. Here, the LS is an entity that manages location measurements and can perform a location management function (LMF). In addition, the LS may be referred to as an LMF or other names. In both LTE and NR systems, LPP is supported, and the following tasks for positioning can be performed by the LPP.

[0105] * Positioning capability exchange,

[0106] * Auxiliary data transmission,

[0107] * Location information transmission,

[0108] * Error handling, and

[0109] *Aborted.

[0110] The terminal and the LS can perform the above tasks through LPP. The BS can allow the terminal and the LS to exchange positioning information. For example, the BS can deliver / forward the positioning-related configuration information indicated by the LS to the terminal. The exchange of positioning information through LPP can be performed transparently. That is, when the terminal and the LS server exchange positioning information, the BS does not participate in configuring the positioning information (the BS performs an operation of only forwarding / delivering the positioning (configuration) information configured by the LS to the terminal).

[0111] During the exchange of positioning capabilities, the terminal can exchange supportable positioning information with the LS. For example, information about whether the positioning method supported by the terminal is UE-assisted, UE-based, or both is available can be exchanged with the LS. UE-assisted positioning is a scheme in which the terminal only sends the measurement value of the positioning scheme to the LS based on the received positioning signal, without directly measuring the absolute position of the terminal, and the absolute position of the terminal is calculated by the LS. The absolute position may refer to the two-dimensional (x, y) and three-dimensional (x, y, z) coordinate position information of the terminal based on longitude and latitude. On the other hand, UE-based positioning may be a scheme in which the terminal can directly measure the absolute position of the terminal, and for this purpose, the terminal should receive the positioning signal and the location information of the source of the positioning signal.

[0112] While the LTE system only supports the UE-assisted scheme, the NR system can support both UE-assisted and UE-based positioning.

[0113] Assisted data transmission can be an important factor in positioning, for example, to accurately measure the location of the terminal. Specifically, in the case of assisted data transmission, the LS can provide the terminal with configuration information about the positioning signal, information about candidate cells and transmission reception points for receiving positioning signals, etc. When using DL-TDOA, the information about candidate cells and TRPs for receiving positioning signals may include information about reference cells, reference TRPs, neighboring cells, and neighboring TRPs. In addition, multiple candidates for neighboring cells and neighboring TRPs, and information about which cell and TRP the UE should select to measure the positioning signal can be provided.

[0114] In order for the terminal to accurately measure the position, it is important to appropriately select information about the candidate cells and TRP for use as a reference. For example, when the channel used for the positioning signal received from the corresponding candidate cell and TRP is a line-of-sight (LOS) channel (i.e., a channel with fewer non-LOS (NLOS) channel components), the accuracy of the positioning measurement can be increased. Therefore, when the LS provides the terminal with information about the candidate cells and TRP (which is a reference for performing positioning) by collecting various information, the terminal can perform more accurate positioning measurements.

[0115] The location information transmission may be performed through the LPP. The LS may request the terminal for location information, and the terminal may provide the LS with measured location information in response to the request.

[0116] In UE-assisted positioning, the corresponding location information may be a measurement value about a positioning scheme based on a received positioning signal. On the other hand, in UE-based positioning, the corresponding location information may be a two-dimensional (x, y) and three-dimensional (x, y, z) coordinate position value of the terminal. When the LS requests location information from the terminal, the LS may include the required accuracy, response time, etc. in the positioning service quality (QoS) information and request the location information. When requesting the corresponding positioning QoS information, the terminal should provide the LS with the measured location information to meet the corresponding accuracy and response time, and when it is impossible to meet the QoS, the terminal may consider error handling and / or termination. However, this is only an example, and in cases other than the case where it is impossible to meet the QoS, error handling and termination may be performed on the positioning.

[0117] The positioning protocol defined between the BS and the LS is called LPPa in the LTE system, and the following functions may be performed between the BS and the LS.

[0118] *E-CID location information transmission,

[0119] *OTDOA information transmission,

[0120] * General error status reporting, and

[0121] * Auxiliary information transmission.

[0122] The positioning protocol defined between the BS and the LS is called NRPPa in the NR system and includes tasks performed by LPPa, and the following functions may be additionally performed between the BS and the LS.

[0123] * Transmission of positioning information,

[0124] * Measurement information transmission, and

[0125] *TRP information transmission.

[0126] Unlike LTE systems, NR systems support more positioning technologies. Therefore, various positioning solutions can be supported through positioning information transmission.

[0127] For example, positioning measurements can be performed by the BS through a positioning sounding reference signal (SRS) sent by the terminal. Therefore, information related to the configuration and activation / deactivation of the positioning SRS can be exchanged between the BS and the LS as positioning information. Measurement information transmission can be a function of exchanging information related to multi-RTT, UL-TDOA, and UL-AOA that are not supported in the LTE system between the BS and the LS. TRP information transmission may include exchanging information related to performing TRP-based positioning, because TRP-based positioning can be performed in the NR system, while cell-based positioning is performed in the LTE system.

[0128] An entity that performs positioning-related configuration and an entity that calculates positioning for measuring the position of a terminal in a SL may be classified into the following three types:

[0129] *UE (without LS),

[0130] *LS (through BS), or

[0131] *LS (through UE).

[0132] In the above, BS may include gNB or eNB, and UE means a terminal that performs transmission and reception through SL. For example, as described above, the terminal that performs transmission and reception through SL may be a vehicle terminal or a pedestrian terminal. In addition, the terminal that performs transmission and reception through SL may include an RSU with a terminal function, an RSU with a BS function, or an RSU with some BS functions and some terminal functions.

[0133] In addition, a terminal performing transmission and reception through the SL may include a Positioning Reference Unit (PRU) whose location is known.

[0134] UE (without LS) may refer to a SL terminal that is not connected to the LS. LS (via BS) refers to a LS connected to the BS. LS (via UE) refers to a LS connected to a SL terminal. In other words, LS (via UE) may indicate a situation where LS is available even when the terminal is not within the coverage of the BS. Here, LS (via UE) may be available only to certain terminals (such as RSU or PRU) other than general terminals. In addition, a terminal connected to the LS via SL may be defined as a new type of device. In addition, only specific terminals that support UE capabilities and are connected to the LS can perform the function of connecting to the LS via SL.

[0135] In Table 1 below, cases 1 to 9 indicate various combinations of entities that perform positioning-related configurations and entities that calculate positioning for measuring the position of a terminal on a SL. The terminal on which position measurement is to be performed is referred to as a target terminal. In addition, a terminal whose position is known and which is capable of providing a positioning signal for measuring the position of a target terminal is referred to as a positioning reference (PosRef) terminal. Therefore, the PosRef terminal may have its own location information, and the location information of the terminal may be provided together with the S-PRS. In other words, the location of the PosRef terminal is known. In this document, the terms target terminal and PosRef terminal are merely examples for ease of description, do not limit the technical scope of the present disclosure, and may be replaced by other terms. For example, the PosRef terminal may also be referred to as an anchor terminal.

[0136] Positioning configuration can be classified into a UE-configured scheme and a network-configured scheme. In Table 1, when the positioning configuration is UE (no LS), the UE-configured scheme can be applied. The advantage of the UE-configured scheme is that positioning configuration can be performed even when the terminal is not within the coverage of the network (BS).

[0137] In Table 1, in the case where the positioning configuration is LS (through BS), the network configuration scheme can be applied. In the network configuration scheme, when the terminal is within the network coverage, the positioning calculation and measurement information are reported to the BS, and then the LS connected to the BS performs the measurement of the position of the target UE. Therefore, delays may occur due to signals related to the position measurement, but more accurate position measurement is possible.

[0138] In Table 1, the case where the positioning configuration is LS (by UE) may not correspond to the scheme configured by the network because the terminal is not configured within the network coverage by the BS. In addition, in the case where the LS connected to the terminal provides the configuration, but it is not classified as configured by the terminal, it may not correspond to the method configured by the UE. However, in the case where it is classified as configured by the terminal, it may correspond to the scheme configured by the UE. Therefore, in the case of LS (by UE), it can be named in a scheme other than the scheme configured by the UE or the network.

[0139] As described above, positioning calculation can be classified into two schemes, i.e., UE-assisted scheme and UE-based scheme. In Table 1, the case where positioning calculation is UE (without LS) can correspond to the UE-based scheme, and the case where positioning calculation is LS (through BS) or LS (through UE) can generally correspond to the UE-assisted scheme. However, in the case where the positioning calculation is LS (through UE) and the corresponding LS is interpreted as a terminal, LS (through UE) can also correspond to the UE-based scheme.

[0140]

Table 1

[0141]

[0142]

[0143] In Table 1, the positioning configuration information may include S-PRS configuration information. The S-PRS configuration information may be pattern information of the S-PRS and / or information related to the time / frequency transmission position. In addition, the positioning calculation may be performed by the terminal receiving the S-PRS and performing measurements based on the received S-PRS, and the positioning measurement and calculation methods may vary depending on which positioning method is applied. The measurement of the position information in the SL may be absolute positioning to provide two-dimensional (x, y) and three-dimensional (x, y, z) coordinate position values ​​of the terminal, or relative positioning to provide relative two-dimensional or three-dimensional position information from another terminal. In addition, the position information in the SL may be ranging information including one of the distance and direction from another terminal. When the ranging in the SL includes both distance and direction information, the ranging may have the same meaning as relative positioning. In addition, as positioning methods, SL time difference of arrival (SL-TDOA), SL angle of departure (SL-AOD), SL multi-RTT, SL RTT, SL angle of arrival (SL-AOA), etc. may be considered.

[0144] Figures 4 to 6 Calculation of the location of the terminal by SL according to an embodiment is shown. However, in the present disclosure, calculation of the location of the terminal by SL is not limited to Figures 4 to 6 Example shown.

[0145] exist Figures 4 to 6 In the above, "configuration" indicates signaling of positioning configuration information. "S-PRS" indicates transmission of S-PRS, and in the case of S-PRS transmission, it can be performed in two directions or in one direction. "Measurement" indicates transmission of measurement positioning information or measurement information used for positioning. "Known location" indicates transmission of location information (known location) known by the terminal.

[0146] refer to Figure 4 , (a) shows an example in which an SL terminal not connected to the LS provides a positioning configuration and a target terminal not connected to the LS performs a positioning calculation. This may correspond to case 1 of Table 1. In this case, the target terminal may broadcast, unicast, or multicast an indication of positioning-related configuration information to another terminal via the SL. In addition, the target terminal may perform a positioning calculation based on the provided positioning signal.

[0147] exist Figure 4 In (b), an example is shown in which a SL terminal not connected to the LS provides a positioning configuration, and the target terminal is within the network coverage, so the LS connected to the BS performs positioning calculation. This may correspond to case 2 of Table 1.

[0148] In this case, the target terminal can broadcast, unicast or multicast the indication of the positioning related configuration information to another terminal through the SL. In addition, because the target terminal is within the coverage of the BS, the target terminal performs positioning measurement based on the provided configuration information and reports the measured positioning information to the BS. Then, the corresponding measurement information can be reported to the LS connected to the BS, so that the LS can perform positioning calculations.

[0149] exist Figure 4 In (c), an example is shown in which a SL terminal not connected to the LS provides a positioning configuration and the LS performs positioning calculations through the SL terminal connected to the LS. This may correspond to case 3 of Table 1.

[0150] In this case, the target terminal can broadcast, unicast or multicast an indication of positioning-related configuration information to another terminal through the SL. In addition, the target terminal performs positioning measurements based on the provided positioning signal and reports the measured positioning information to the terminal connected to the LS, because the target terminal and the terminal connected to the LS are within the coverage of the SL. In (c), the terminal connected to the LS is shown as a PosRef UE (RSU), but it should be noted that the terminal can be a terminal other than an RSU. The corresponding measurement information can then be reported to the LS connected to the PosRef UE (RSU), so that the LS can perform positioning calculations based on this.

[0151] refer to Figure 5,(a) shows an example where the SL terminal is within the network coverage, the LS connected to the BS provides positioning configuration, and the target terminal not connected to the LS performs positioning calculation. This may correspond to case 4 of Table 1.

[0152] In this case, the positioning configuration information can be provided by the LS connected to the BS using a positioning protocol such as LPP. In addition, the target terminal can perform positioning calculations based on the provided configuration information and the positioning signal.

[0153] exist Figure 5 In (b), an example is shown, in which the SL terminal is located within the network coverage, the LS connected to the BS provides positioning configuration, the target terminal is located within the network coverage, and the LS connected to the BS performs positioning calculation. This may correspond to case 5 in Table 1.

[0154] In this case, the positioning configuration information can be provided by the LS connected to the BS using a positioning protocol such as LPP. In addition, the target terminal can perform positioning measurements based on the provided configuration information and the positioning signal, and can report the measured positioning information to the BS because the target terminal is within the coverage of the BS. Then, the corresponding measurement information can be reported to the LS connected to the BS, so that the LS can perform positioning calculations based on the measurement information.

[0155] exist Figure 5 In (c), the SL terminal is located within the network coverage, the LS connected to the BS provides positioning configuration, and the LS performs positioning calculation through the SL terminal connected to the LS. This may correspond to case 6 in Table 1.

[0156] In this case, the positioning configuration information can be provided by the LS connected to the BS using a positioning protocol such as LPP. In addition, the target terminal can perform positioning measurements based on the provided configuration information and positioning signals, and can report the measured positioning information to the terminal connected to the LS, because the target terminal is within the SL coverage of the terminal connected to the LS. In (c), the terminal connected to the LS is shown as a PosRef UE (RSU), but the terminal can be a terminal other than an RSU. Then, the corresponding measurement information can be reported to the LS connected to the PosRef UE (RSU), and thus the LS can perform positioning calculations based on the reported measurement information.

[0157] refer to Figure 6 , (a) shows an example in which the LS provides positioning configuration through the SL terminal connected to the LS, and the target terminal not connected to the LS performs positioning calculation. This may correspond to case 7 in Table 1.

[0158] In this case, the positioning configuration information can be provided by the LS connected to the terminal using a positioning protocol such as LPP. In addition, the target terminal can perform positioning calculations based on the provided configuration information and the positioning signal.

[0159] exist Figure 6 In (b), LS provides positioning configuration through the SL terminal connected to the LS, the target terminal is located within the network coverage, and the LS connected to the BS performs positioning calculation. This may correspond to case 8 in Table 1.

[0160] In this case, the positioning configuration information can be provided by the LS connected to the terminal using a positioning protocol such as LPP. In addition, the target terminal can perform positioning measurements based on the provided configuration information and positioning signals, and can report the measured positioning information to the BS because the target terminal is within the coverage of the BS. The corresponding measurement information can be reported to the LS connected to the BS, so that the LS can perform positioning calculations based on the measurement information.

[0161] exist Figure 6 In (c), LS provides positioning configuration through the SL terminal connected to the LS and LS performs positioning calculation through the SL terminal connected to the LS. This may correspond to case 9 in Table 1.

[0162] In this case, the positioning configuration information can be provided by the LS connected to the terminal using a positioning protocol such as LPP. In addition, the target terminal can perform positioning measurements based on the provided configuration information and positioning signals, and can report the measured positioning information to the terminal connected to the LS, because the target terminal is within the SL coverage of the terminal connected to the LS. In (c), the terminal connected to the LS is shown as a PosRef UE (RSU), but the terminal can be a terminal other than an RSU. Then, the corresponding measurement information can be reported to the LS connected to the PosRef UE (RSU), and therefore, the LS can perform positioning calculations based on the reported measurement information.

[0163] Figure 7 It is shown that positioning is performed using an RTT scheme according to an embodiment.

[0164] refer to Figure 7 , UE-A and UE-B may correspond to the target terminal and PosRef terminal respectively. Figure 7 In the example, UE-A and UE-B are not limited to the target UE and PosRef UE, respectively. In other words, UE-A may correspond to the PosRef terminal, and UE-B may correspond to the target terminal.

[0165] exist Figure 7In FIG. 1 , a method for performing RTT (single RTT) in the case where there is a pair between a target terminal and a PosRef terminal is shown. However, the target terminal may perform RTT using a plurality of PosRef terminals. In this case, Figure 7 Different, there may be multiple pairs between the target terminal and one PosRef terminal, and the method may be called multi-RTT. Multi-RTT can be used for the target terminal to perform absolute positioning. The RTT method can be used to calculate the time of flight (ToF), and the relationship formula of "speed = time / distance" or "distance = speed × time" or "time = distance / speed" can be used to measure the distance. Here, ToF represents time, and the speed of light can be applied as the speed.

[0166] exist Figure 7 , (a) shows a one-sided RTT method (or one-way RTT method), in which RTT measurement can be performed by sending positioning signals from UE-A to UE-B and from UE-B to UE-A. Specifically, UE-A can calculate the time difference T between the time when it sends the positioning signal to UE-B and the time when it receives the positioning signal from UE-B. round 701. UE-B may calculate the time difference T between the time when it receives the positioning signal from UE-A and the time when it sends the positioning signal to UE-A reply 702. From this, ToF can be calculated as shown in Equation 1 below.

[0167] [Equation 1]

[0168] ToF = 1 / 2 (T round -T reply )

[0169] To calculate Equation 1 by UE-A, T calculated by UE-B reply The information should be indicated to UE-A. However, in order for UE-B to calculate equation 1, T calculated by UE-A should be indicated to UE-B. round information.

[0170] exist Figure 7 In FIG. 1 , (b) shows a two-sided RTT scheme, in which UE-A sends a positioning signal to UE-B, UE-B sends a positioning signal to UE-A, and then UE-A sends a positioning signal to UE-B again, so that RTT measurement can be performed. Specifically, UE-A can calculate the time difference T between the time when it sends a positioning signal to UE-B and the time when it receives the positioning signal from UE-B. round1 701. UE-B may calculate the time difference T between the time when it receives the positioning signal from UE-A and the time when it sends the positioning signal to UE-A reply1702. Thus, UE-A can calculate T reply2 703, that is, the time difference between the time when it receives the positioning signal from UE-B and the time when it sends the second positioning signal to UE-B. UE-B can calculate the time difference T between the time when it sends the positioning signal to UE-A and the time when it receives the second positioning signal from UE-A round2 704. From this, ToF can be calculated as shown in Equation 2 below.

[0171] [Equation 2]

[0172] ToF=(T round1 ×T round2 -T reply1 ×T reply2 ) / (T round1 +T round2 +T reply1 +T reply2 )

[0173] To calculate Equation 2 by UE-A, T calculated by UE-B reply1 and T round 2 information should be indicated to UE-A. However, in order for UE-B to calculate equation 2, T calculated by UE-A should be indicated to UE-B. round1 and T reply2 information.

[0174] Compared with the one-sided RTT according to equation 1, in the two-sided RTT according to equation 2, the influence of the clock drift in each terminal is minimized, so that there is an advantage of improving positioning accuracy. However, additional signal exchange may occur, resulting in additional delay in calculating ToF. In the present invention, the RTT method is not limited to the two methods described above. For example, it can be achieved by reply2 and T round2 Additional positioning signal exchanges after that additionally calculate T reply and T round , to calculate ToF.

[0175] In the present disclosure, one or more of the following embodiments may be used in combination with each other. A terminal capable of providing a positioning signal for position measurement of a target terminal may be referred to as a PosRef (positioning reference) terminal. The position of the PosRef terminal may be known (known position) or may be unknown (unknown position). When the position of the PosRef terminal is known, the corresponding position information may be transmitted to the target terminal, and the target terminal may be based on UE-based execution positioning. Although the present invention includes a congestion control method for positioning signal transmission, the method may be applied to other signal transmission methods as well as positioning signals.

[0176] <First Embodiment>

[0177] The first embodiment provides a method for configuring and transmitting a signal for a terminal to measure a location through a SL.

[0178] Whether the terminal can perform positioning through SL can be determined by UE capabilities, that is, whether the terminal can perform positioning operations, and the corresponding capability information can be sent to other terminals and BS. In this case, whether the terminal can perform positioning through SL can also be determined by whether the SL positioning signal is sent / received. In this case, the SL positioning signal can be an S-PRS to be sent and received for positioning measurement. For example, a certain SL terminal can send and receive S-PRS. In addition, a certain SL terminal may be able to send S-PRS, but not receive S-PRS. In addition, a certain SL terminal may be able to receive S-PRS, but not send S-PRS. In addition, a certain SL terminal may not be able to send and receive S-PRS. Whether the terminal can send / receive S-PRS can be defined by UE capabilities.

[0179] Here, the S-PRS signal is not limited to a specific signal. For example, the corresponding signal may be a SL synchronization signal or another reference signal defined in SL. Alternatively, the S-PRS may be a newly defined reference signal for SL positioning.

[0180] Figure 8 The pattern of S-PRS based on DL PRS according to an embodiment is shown. Note that Figure 8 The S-PRS shown may not be sent with other SL channels and signals in frequency division multiplexing (FDM). This method avoids interference with other channels and signals by only allowing the S-PRS to be sent in the symbol in which the S-PRS is sent. Thus, the accuracy of positioning can be guaranteed.

[0181] refer to Figure 8 , the DL PRS-based pattern can be reused for S-PRS. Figure 8 In (a), the number of PRS symbols and comb pattern supported in DL PRS can also be applied to S-PRS. Figure 8 (b) of FIG. 1 shows an S-PRS pattern in the case of comb teeth = 2 and the number of PRS symbols = 2. Figure 8 (c) in FIG. 1 shows an S-PRS pattern in the case of comb teeth = 2 and the number of PRS symbols = 4. Figure 8 (d) of FIG. 1 shows an S-PRS pattern in the case of comb teeth = 2 and the number of PRS symbols = 6. Figure 8 (e) of FIG. 1 shows an S-PRS pattern in the case of comb teeth-2 and the number of PRS symbols = 12. Figure 8(f) of FIG. 1 shows an S-PRS pattern in the case of comb teeth = 4 and the number of PRS symbols = 4. Figure 8 (g) of FIG. 1 shows an S-PRS pattern in the case of comb teeth = 4 and the number of PRS symbols = 12. Figure 8 (h) of FIG. 1 shows an S-PRS pattern in the case of comb teeth = 6 and the number of PRS symbols = 6. Figure 8 (i) in FIG. 1 shows an S-PRS pattern in the case of comb teeth-6 and the number of PRS symbols = 12. The S-PRS pattern in the case of comb teeth-12 and the number of PRS symbols = 12 is shown in FIG. Figure 8 It is shown in (j) in FIG.

[0182] according to Figure 8 , the S-PRS may have various symbol lengths, and the start position and length of a symbol through which the S-PRS is transmitted may be flexibly determined in a time slot.

[0183] Fig. 9 : is a diagram for explaining a pattern of an S-PRS as an SL positioning signal based on a UL PRS according to an embodiment of the present disclosure. Note that, Fig. 9 The S-PRS shown may not be transmitted with other SL channels and signals in FDM. This is a method for avoiding interference with other channels and signals by allowing the S-PRS to be transmitted only in symbols in which the S-PRS is transmitted. Thus, the accuracy of positioning can be guaranteed.

[0184] refer to Fig. 9 , the S-PRS can be interpreted by reusing the pattern based on the UL SRS used for positioning.

[0185] exist Fig. 9 In (a), the comb pattern and the number of SRS symbols supported in the UL SRS for positioning may be applied to the S-PRS. Fig. 9 (b) of FIG. 1 shows an S-PRS pattern in the case of comb teeth-2 and the number of PRS symbols = 1. Fig. 9 (c) in FIG. 1 shows an S-PRS pattern in the case of comb teeth = 2 and the number of PRS symbols = 2. Fig. 9 (d) of FIG. 1 shows an S-PRS pattern in the case of comb teeth = 2 and the number of PRS symbols = 4. Fig. 9 (e) of FIG. 1 shows an S-PRS pattern in the case of comb teeth = 4 and the number of PRS symbols = 2. Fig. 9 (f) of FIG. 1 shows an S-PRS pattern in the case of comb teeth = 4 and the number of PRS symbols = 4. Fig. 9 (g) of FIG. 1 shows an S-PRS pattern in the case of comb teeth = 4 and the number of PRS symbols = 8. Fig. 9(h) of FIG. 1 shows an S-PRS pattern in the case of comb teeth = 4 and the number of PRS symbols = 12. Fig. 9 (i) of FIG. 1 shows an S-PRS pattern in the case of comb teeth = 8 and the number of PRS symbols = 4. Fig. 9 (j) in FIG. 1 shows an S-PRS pattern in the case of comb teeth = 8 and the number of PRS symbols = 8. Fig. 9 (k) in FIG. 1 shows the S-PRS pattern in the case of comb teeth=8 and the number of PRS symbols=12.

[0186] according to Fig. 9 , the S-PRS may have various symbol lengths, and the start position and length of a symbol through which the S-PRS is transmitted may be flexibly determined in a time slot.

[0187] Although already Figure 8 and Fig. 9 Examples of various S-PRS patterns are described in , but the scope of the present disclosure is not limited thereto.

[0188] In addition, the positioning methods that can be supported by the terminal can be defined as terminal capabilities. For example, SL-TDOA, SL-AOD, SL multi-RTT, SL RTT, SL E-CID, SL-AOA, etc., but not limited to this. The supportable SL positioning methods can be determined by UE capabilities, and the corresponding capability information can be sent to other UEs and BSs.

[0189] When the terminal performs positioning through the SL, configuration information related to positioning may be (pre-)configured. For example, the S-PRS information may be (pre-)configured as positioning related information. Specifically, the activation / deactivation of the S-PRS transmission may be (pre-)configured. When the S-PRS transmission is deactivated, the corresponding terminal may not perform S-PRS transmission even if the S-PRS transmission is indicated / requested by the LS or other terminals.

[0190] In addition, while the transmission bandwidth (allocation region in frequency) and period (allocation region in time) of the S-PRS may be configured in various ways, the corresponding information may be (pre-)configured.

[0191] As another example, refer to Figures 8 to 9As described, the number of available comb patterns and PRS symbols and the position (starting symbol) at which the PRS is sent in the time slot can be (pre-)configured. As another example, information about the positioning method can be (pre-)configured as positioning-related information. For example, which positioning methods are available can be (pre-)configured. As positioning methods for UEs, there may be SL-TDOA, SL-AOD, SL multi-RTT, SL RTT, SL E-CID, SL-AOA, etc., and the supported SL positioning methods are determined by the UE capabilities, and the corresponding capability information can be sent to other terminals and BSs. In addition, among the SL positioning methods that can be supported based on the UE capabilities, the available positioning methods can be (pre-)configured.

[0192] As discussed with reference to Table 1, when the terminal does not receive the positioning configuration from another terminal or LS, the terminal can comply with the positioning configuration information that is pre-configured and then stored therein. For example, in this case, the terminal may be outside the network coverage. As another example, no positioning-related configuration information is received from any other terminal. After a specific time point, the terminal may be configured with positioning information from another terminal or LS. In the case of the corresponding UE (without LS) or LS (by UE) of Table 1 in which the terminal is configured with positioning information from another terminal, the corresponding information may have been sent via broadcast, unicast or multicast through SL, and may be indicated by SCI (first stage SCI or second stage SCI), or may be indicated by PC5-RRC or SLMAC-CE. In the case of the corresponding LS (by UE) in which the LS is connected to the terminal and the terminal is configured with the positioning information, the corresponding information can be indicated from the higher layer of the terminal. However, in the case of the LS (by BS) corresponding to Table 1, in which the terminal is configured with positioning information from the LS connected to the BS, the terminal may be configured with corresponding information from the BS in a cell-common manner. Here, cell-common may indicate that the terminal in the cell receives the same information configuration from the BS. In this case, the terminal may consider a method for receiving SL-SIB from the BS and obtaining cell common information. In addition, in the case of LS (through BS) corresponding to Table 1, in which the terminal is configured with positioning information from the LS connected to the BS, the corresponding information may mean configuring the terminal in a UE-specific manner after establishing an RRC connection with the BS.

[0193] As described above, when the terminal does not receive the positioning configuration from another terminal or LS, the terminal may send or receive the positioning signal according to the positioning configuration information that is pre-configured and then stored therein. After a specific time point, the terminal may be configured with positioning information from another terminal or LS. In this case, the configured information may be one or more pieces of information. For example, in the case of S-PRS information, it may be determined that only one pattern is configured, and it may be allowed to configure more than one pattern information.

[0194] When one or more pattern information is configured, the terminal may send the corresponding configuration information to the BS and LS. The LS may determine the appropriate S-PRS pattern and indicate the determined S-PRS pattern to the terminal. However, the terminal may determine the pattern used in one or more S-PRS pattern information and send the corresponding information to other terminals via broadcast, unicast, or multicast through the SL. In this case, the corresponding information may be indicated by SCI (first stage SCI or second stage SCI), or may be indicated by PC5-RRC or SL MAC-CE.

[0195] As another example, it may be determined that the information about the positioning method is (pre)configured in only one method, and (pre)configuration of information about one or more positioning methods may be allowed.Here, the information about the positioning method may include information about whether the method is UE-based or UE-assisted.

[0196] Alternatively, the information about the positioning method may include information about whether the method is absolute positioning, relative positioning or ranging.

[0197] Alternatively, the information about the positioning method may include information about whether the method is SL-TDOA, SL-AOD, SL Multi-RTT, SL E-CID or SL-AOA.

[0198] When one or more mode information is configured, the terminal can send the corresponding configuration information to the BS or LS. The LS can determine the appropriate positioning method and indicate the determined positioning method to the terminal. However, the terminal can determine the method used in the information about one or more positioning methods, and send the corresponding information to other terminals via broadcast, unicast or multicast through the SL. In this case, the corresponding information can be indicated by SCI (first stage SCI or second stage SCI), or the corresponding information can be indicated by PC5-RRC or SL MAC-CE.

[0199] When the terminal performs positioning through SL, the terminal can send a positioning signal through SL. Here, the positioning signal can be called S-PRS. The methods of sending positioning signals in SL can be divided into two categories:

[0200] * Transmission of positioning signal from PosRef terminal to target terminal, or

[0201] * Transmission of positioning signal from the target terminal to the PosRef terminal.

[0202] Depending on the positioning method used, one or both of the above categories can be performed. For example, when SL-TDOA is performed, SL positioning can be performed by sending S-PRS using the first method. However, when SL multi-RTT or SL RTT is performed, both S-PRS transmission methods may be required.

[0203] Reference again Figure 7 , UE-A and UE-B may correspond to the target terminal and PosRef terminal respectively. Figure 7 , UE-A and UE-B are not limited to the target UE and PosRef UE, respectively. In other words, UE-A may correspond to the PosRef terminal, and UE-B may correspond to the target terminal. In addition, the S-PRS sent from the PosRef terminal to the target terminal and the S-PRS sent from the target terminal to the PosRef terminal may be the same type of positioning signals or different types of positioning signals.

[0204] In addition, in SL, the terminal can perform absolute positioning, relative positioning, or ranging. First, as described above, absolute positioning (absolute position) can mean the two-dimensional (x, y) and three-dimensional (x, y, z) coordinate position information of the terminal in terms of longitude and latitude. The target terminal may need multiple PosRef terminals for absolute positioning. In addition, the target terminal should receive known location information from multiple PosRef terminals for absolute positioning. For example, when the target terminal performs RTT using multiple PosRef terminals, Figure 7 In the example, there can be multiple pairs between the target terminal and a PosRef terminal. In addition, this can be called multi-RTT. Then, relative positioning (relative position) can mean the relative two-dimensional or three-dimensional position information from other terminals. Therefore, for the relative positioning of the target terminal, for example, Figure 7 As shown, only one PosRef terminal may be needed. In addition, the target terminal should receive known location information from the corresponding PosRef terminal. In addition, by additionally measuring or receiving direction information, the target terminal can identify relative two-dimensional or three-dimensional location information from the PosRef terminal. Ranging can mean measuring the distance or direction from another terminal. In the case of measuring distance, for example, Figure 7 As shown, only one PosRef terminal may be required.

[0205] Furthermore, when only the distance or direction to other terminals is measured, there is no need to receive known location information from the PosRef terminal. When ranging in SL includes both distance and direction information, ranging can have the same meaning as relative positioning.

[0206] <Second Embodiment>

[0207] The second embodiment includes a method for selecting and allocating resources for sending a SL positioning signal.

[0208] As described above, the following contents may be included as SL positioning signals.

[0209] -S-PRS,

[0210] - measurement report, and / or

[0211] -Location information transmission.

[0212] However, in the present disclosure, the SL positioning signal is not limited to the above-mentioned signals. For example, the SL positioning signal may be a signal requesting an S-PRS or a signal including information required to perform positioning. The terminal may allocate resources for sending positioning signals as described above, and send signals in corresponding resources. The following alternatives may be considered as resource allocation methods for positioning signal transmission. However, the present disclosure is not limited to the following alternatives.

[0213] -Alternative 1: Positioning signal transmission in the resource region where PSSCH is transmitted

[0214] -Alternative 2: Positioning signal transmission in dedicated resources different from the resource region where PSSCH is transmitted

[0215] In alternative scheme 1, the terminal can send a positioning signal in a resource area allocated according to the existing SL resource allocation method for PSSCH transmission. Specifically, resources for PSSCH transmission can be allocated from the BS to the terminal, or the terminal can allocate resources for PSSCH transmission through direct sensing and resource selection. When positioning signal transmission is performed in a resource area where PSSCH is transmitted, as in alternative scheme 1, resource efficiency can be improved by sharing the transmission resources of PSSCH and positioning signals. However, conflicts and interferences between the positioning signal and the signal transmitted through PSSCH may occur. This may result in the inability to guarantee the accuracy of SL positioning.

[0216] In alternative 2, a method for sending a positioning signal in a dedicated resource different from the resource area for sending PSSCH can be considered. Specifically, resources for positioning signal transmission separated from the resource area for PSSCH transmission from the BS can be allocated to the terminal, or the terminal can allocate resources for positioning signal transmission separated from the resource area for PSSCH transmission through direct sensing and resource selection. Through this method, the positioning accuracy can be improved by avoiding resource conflicts and interference between the signal sent through PSSCH and the positioning signal. In addition, when allocating transmission resources for S-PRS transmission, the transmission time and frequency area of ​​​​S-PRS can be allocated more flexibly. However, since the transmission resources of the positioning signal and PSSCH are always used separately, resource efficiency may be reduced.

[0217] As a resource allocation method for positioning signal transmission, it is possible to consider selecting one of the alternatives 1 and 2 presented above, or using both alternatives 1 and 2. For example, when both alternatives 1 and 2 are considered, it is possible to (pre)configure which method is supported. For example, when using (pre)configuration as alternative 1 or (pre)configuration as alternative 2, the terminal can operate in the (pre)configured alternative. However, when both alternatives 1 and 2 are (pre)configured or "any" (pre)configuration method is allowed, the terminal should operate by selecting one of alternatives 1 and 2. In this case, information about which alternative is selected and operated can be sent to other terminals via broadcast, unicast or multicast of SL. In this case, the corresponding information can be indicated by SCI (e.g., first stage SCI or second stage SCI), or can be indicated by PC5-RRC or SL MAC-CE.

[0218] As another example, when both alternative 1 and alternative 2 are used, the terminal may select alternative 1 or alternative 2 according to conditions. The conditions may include the required positioning accuracy. For example, when high positioning accuracy is required, alternative 2 may be selected to avoid resource conflicts and interference between the signal sent through the PSSCH and the positioning signal. Alternatively, when high positioning accuracy is not required, alternative 1 may be selected. In the present disclosure, among the positioning signals, S-PRS may be considered as a method of operating as alternative 2 and other positioning signals such as measurement reports or location information transmission as alternative 1 operations.

[0219] Fig.10 A method for transmitting a SL positioning signal in a dedicated resource region different from a resource region for transmitting a PSSCH according to an embodiment is shown. Specifically, Fig.10 An example for explaining Alternative 2 is shown.

[0220] refer to Fig.10 In (a), the resource region in which the PSSCH is transmitted and the resource region in which the positioning signal is transmitted can be distinguished by the TX pool. Specifically, the transmission resource region can be distinguished by configuring the TX pool of the PSSCH and the TX pool of the positioning signal so as not to overlap in the time domain.

[0221] exist Fig.10 In (b), the resource region for sending PSSCH and the resource region for sending positioning signal can be distinguished by SL BWP. When multiple SL BWPs are supported in SL, a specific SL BWP can be classified into a BWP for PSSCH transmission and another SL BWP for positioning signal transmission by classification in the frequency region, which is distinguished from the BWP for PSSCH transmission. However, in order to support this scheme, the terminal may be required to perform an SL BWP switching operation additionally.

[0222] Here, the method for transmitting the positioning signal in a dedicated resource region different from the resource region for transmitting the PSSCH is not limited to the reference Fig.10 Alternatively, alternative 2 may also be applied only to S-PRS.

[0223] By the method of this embodiment, resource allocation for positioning signals can be performed in a dedicated resource region different from PSSCH transmission.Here, resource allocation can include both Mode 1 and Mode 2 methods.

[0224] As described above, mode 1 is a method in which the BS performs resource allocation and provides resource allocation information to the terminal through DL control information (DCI). The BS may receive information required for positioning signal transmission resource allocation from the target terminal or LS. The corresponding information may be information related to the positioning requirements required to perform SL positioning. In mode 1, the terminal may perform resource allocation using the resource allocation information indicated by the corresponding DCI, and may indicate the corresponding information to other terminals through SCI. In contrast, mode 2 is a method in which the terminal performs resource allocation through direct sensing. After performing resource allocation, the terminal may indicate resource reservation information to other terminals through SCI. In mode 1, the DCI for positioning signal transmission resource allocation may be a new DCI format that is distinguished from the existing DCI format 3_0 (e.g., DCI format 3_1). In addition, in mode 2, the SCI indicating the resource allocation information for positioning signal transmission may be a new SCI format that is distinguished from the existing SCI format 1_A (e.g., SCI format 1_B).

[0225] When selecting and allocating positioning signal transmission resources, the terminal and the BS need to select the following parameters to meet the positioning requirements. Here, the parameters considered in the selection and allocation of positioning transmission resources are not limited to the length of the symbol that can be allocated to the S-PRS in one time slot, the number of subchannels that can be allocated to the S-PRS, the S-PRS repetition factor, the S-PRS delay limit, the frequency density of transmitting the S-PRS, the S-PRS comb size, or the parameters of the S-PRS power, as described below.

[0226] The length of a symbol that can be allocated to S-PRS in one slot

[0227] The length of the symbol that can be allocated to S-PRS in a time slot can be referred to Figures 8 to 9 .exist Figure 8 and Fig. 9 In the present invention, S-PRS can be designed as symbols with various lengths. The length of the symbol that can be allocated to S-PRS in a time slot can be (pre-) configured. In this case, the (pre-) configured length of the symbol that can be allocated to S-PRS can be configured as one value or one or more values. When the (pre-) configured length of the allocable S-PRS symbol is configured as one or more values, the terminal can determine the length of the S-PRS symbol and indicate the corresponding information to other terminals through SCI (first stage SCI or second stage SCI) or PC5-RRC or SL MAC-CE. In the case of indication by SCI, a new SCI format can be defined. The terminal can determine the starting position and length of the symbol through which the S-PRS is sent in the time slot based on the resource allocation result of the S-PRS.

[0228] The number of subchannels that can be allocated to S-PRS

[0229] The number of subchannels that can be allocated to S-PRS can also be (pre) configured. When the (pre) configured number of subchannels that can be allocated to S-PRS is configured as one or more candidate values, the terminal can determine the number of subchannels and indicate the corresponding information to other terminals through SCI (first stage SCI or second stage SCI) or through PC5-RRC or SL MAC-CE. In the case of indication through SCI, a new SCI format can be defined. The terminal can determine the number of subchannels allocated to S-PRS in a time slot based on the resource allocation result of S-PRS.

[0230] S-PRS repeat factor

[0231] The S-PRS repetition factor indicates that the S-PRS is repeatedly transmitted in one or more time slots, and the repetitive factor can be (pre) configured. In this case, the (pre) configured S-PRS repetition factor can be configured as one value or one or more values. Depending on the configured value, S-PRS repetition may not be possible. When the (pre) configured S-PRS repetition factor is configured as one or more values, the terminal can determine the S-PRS repetition factor and indicate the information to other terminals through SCI (first stage SCI or second stage SCI) or through PC5-RRC or SL MAC-CE. In the case indicated by SCI, a new SCI format can be defined. The terminal can determine the S-PRS repetition factor based on the resource allocation result of the S-PRS. For example, the S-PRS repetition factor can be applied to continuous logical time slots of the SL. Alternatively, the S-PRS repetition factor can also be applied to non-continuous logical time slots of the SL, or the S-PRS repetition factor can be limited and applied only to physically continuous time slots.

[0232] S-PRS delay bound

[0233] The S-PRS delay bound is a requirement for S-PRS transmission. When allocating transmission resources for S-PRS, if the transmission time of the corresponding resources is delayed, a delay may occur when performing positioning, so the S-PRS delay should be met when selecting and allocating S-PRS transmission resources. The value associated with the S-PRS delay bound can be (pre-)configured.

[0234] Frequency density of transmitting S-PRS

[0235] The frequency density of transmitting S-PRS may indicate whether S-PRS is transmitted in every RB in a frequency region with 1 density in units of RB, whether S-PRS is transmitted in every 2 RBs in a frequency region with 1 / 2 density in units of RB, or whether S-PRS is transmitted in every 4 RBs in a frequency region with 1 / 4 density in units of RB, and the corresponding density may be (pre-) configured. In this case, the (pre-) configured density in units of RB on the frequency of S-PRS may be configured as one value or one or more values. When the (pre-) configured density in units of RB on the frequency of S-PRS is configured as one or more values, the terminal may determine the density in units of RB on the frequency of S-PRS, and indicate the corresponding information to other terminals through SCI (first stage SCI or second stage SCI) or through PC5-RRC or SL MAC-CE. In the case of indication through SCI, a new SCI format may be defined. The terminal may determine the density in units of RB on the frequency of S-PRS based on the resource allocation result of S-PRS.

[0236] S-PRS comb tooth size

[0237] The size of the S-PRS comb teeth can be referenced Figures 8 to 9 .exist Figure 8 and Fig. 9 In the present invention, the S-PRS can be sent with various comb tooth sizes. The comb tooth size that can be allocated to the S-PRS can be (pre-) configured. In this case, the (pre-) configured comb tooth size can be configured as one value or one or more values. When the (pre-) configured S-PRS comb tooth size is configured as one or more values, the terminal can determine the S-PRS comb tooth size and indicate the corresponding information to other terminals through SCI (first stage SCI or second stage SCI) or through PC5-RRC or SL MAC-CE. In the case of indication through SCI, a new SCI format can be defined. The terminal can determine the S-PRS comb tooth size based on the resource allocation result of the S-PRS.

[0238] S-PRS Power

[0239] The S-PRS power may be adjusted based on the SL path loss or the DL path loss, and the adjustable power range may be (pre-)configured.

[0240] Generally, the longer the length of the symbol that can be allocated to S-PRS in a time slot, the more subchannels that can be allocated to S-PRS, the larger the S-PRS repetition factor, the higher the frequency density through which S-PRS is sent, and the smaller the S-PRS comb tooth size, the larger the time and frequency area for sending S-PRS, so the positioning accuracy can be improved. In addition, as the S-PRS power increases, the positioning accuracy can be improved. Therefore, when selecting and allocating S-PRS transmission resources, the terminal and BS can determine the allocated S-PRS symbol length, the number of allocated S-PRS subchannels, the PRS repetition factor, the density on the frequency of sending S-PRS, the S-PRS comb tooth size, etc. to meet the positioning requirements. In addition, the S-PRS power can be adjusted.

[0241] When multiple TX resource pools for S-PRS transmission are configured for the terminal, and when the terminal should select one TX resource pool for S-PRS transmission, the terminal can select the TX resource pool for S-PRS transmission based on configuration information related to the following parameters (pre-) configured in the TX resource pool.

[0242] *The length of a symbol that can be allocated to S-PRS in one time slot,

[0243] *The number of subchannels that can be allocated to S-PRS,

[0244] *S-PRS repetition factor,

[0245] *S-PRS delay bound,

[0246] * the density of the frequencies on which S-PRS is transmitted,

[0247] *S-PRS comb tooth size, and / or

[0248] *S-PRS power.

[0249] Specifically, the terminal can select a TX resource pool that can meet the positioning accuracy. For example, when TX resource pools A and B are configured, when the (pre-) configured length of the symbol length that can be allocated to the S-PRS in the case of TX resource pool A is short, and the (pre-) configured length of the symbol length that can be allocated to the S-PRS in the case of TX resource pool B is long, the terminal can select TX resource pool B when high positioning accuracy is required.

[0250] Fig.11 It is shown that relevant parameters are applied when selecting and allocating transmission resources of S-PRS according to an embodiment.

[0251] refer to Fig.11 , 1100 represents a resource pool area specifically allocated for SL positioning (i.e., S-PRS transmission). As described above, the corresponding area may be an area distinguished from the resource pool area for transmitting PSSCH. 1101 represents a resource area allocated for S-PRS transmission in area 1100. 1102 and 1103 show examples of different resource allocations. Specifically, 1102 shows a case where S-PRS is allocated to all symbols in one time slot, a case where S-PRS repetition factor = 2 (repetition in two time slots), and a case where four subchannels in the frequency are allocated to the S-PRS transmission area. In contrast, 1103 shows a case where S-PRS is allocated to some symbols within one time slot, a case where S-PRS repetition factor = 1 (no repetition is performed), and a case where two subchannels in the frequency are allocated to the S-PRS transmission area. Compared with 1103, 1102 allocates more resources for S-PRS transmission and may be more advantageous in improving positioning accuracy.

[0252] <Third Embodiment>

[0253] In the third embodiment, a structure of a time slot for sending an SL positioning signal is provided. Specifically, when an S-PRS is sent, the corresponding time slot structure may be different from the existing SL time slot structure. In the above-mentioned second embodiment, it is described that the scheme of mapping the S-PRS to the resource domain in time and frequency may vary according to the resource allocation for S-PRS transmission. In this third embodiment, a time slot structure for S-PRS transmission and a method for mapping the S-PRS to the time and frequency region of the time slot according to the resource allocation for S-PRS transmission will be described.

[0254] Fig.12 A time slot structure for transmitting a SL positioning signal according to an embodiment is shown.

[0255] refer to Fig.12 , in (a), the SL slot structure for PSSCH transmission is shown. Specifically, in (a), the first symbol is an automatic gain control (AGC), and the last symbol can be used as a protection symbol for the terminal to switch reception and transmission. In the case of an AGC symbol, the second symbol can be copied and used as an AGC symbol. In addition, in (a), PSCCH (first SCI transmission) and PSSCH (data transmission) can be multiplexed and transmitted. Specifically, the PSCCH can be mapped in the PSSCH and time-division multiplexed (TDMed) or time-division multiplexed and frequency-division multiplexed from the lowest PRB of the PSSCH scheduled from the consecutive 2 or 3 symbols after the AGC symbol, or time-division multiplexed and frequency-division multiplexed, and transmitted. In addition, the second SCI can be mapped to a symbol in which the first PSSCH demodulation reference signal (DMRS) is transmitted in the PSSCH region, and transmitted. When S-PRS is transmitted in the SL slot structure shown in (a), one or more of the following restrictions may apply.

[0256] -S-PRS can be sent in the symbols where PSSCH is sent,

[0257] -S-PRS is not sent in the symbols where PSCCH is sent,

[0258] - S-PRS is not transmitted in the symbol in which the second SCI is transmitted, or

[0259] -S-PRS is not transmitted in the symbols in which PSSCH DMRS is transmitted.

[0260] When sending the above restrictions and Fig.12 When the S-PRS is transmitted in the SL slot structure shown in (a), the number of symbols in which the S-PRS can be transmitted may be limited.

[0261] exist Fig.12 In (b) to (d) of FIG. 1 , an example of an SL time slot structure for positioning signal transmission is shown. Specifically, as shown in (b) to (d), the first symbol can be used as an AGC symbol, and the last symbol can be used as a guard symbol. For example, in the case of an AGC symbol, the second symbol can be copied and used as an AGC symbol, or in the case where no signal is sent in the second symbol, the first symbol through which the S-PRS is sent can be copied and used as an AGC symbol. Alternatively, the first symbol through which the S-PRS is always sent can be copied and used as an AGC symbol.

[0262] When the SL slot structure in (a) is used, a newly designed slot structure for S-PRS transmission may be considered to solve the problem that the number of symbols through which S-PRS can be sent may be limited. For example, the second SCI transmission may not be necessary. However, the first SCI transmission through the PSCCH may be necessary for terminal sensing and indication of S-PRS related information.

[0263] As referenced above Figure 8 and Fig. 9 As described above, when considering the symbol lengths of various S-PRSs and determining the starting position and length of the symbol through which the S-PRS is transmitted in the time slot according to the resource allocation of the S-PRS, as Fig.12 As shown in (b) to (d) in FIG. 1 , it may be more advantageous to multiplex the transmission area of ​​S-PRS and PSCCH (first SCI transmission) in FDM. This is because, in the case of Fig.12 In the case where PSCCH is transmitted as shown in (a), the frequency region to which S-PRS is allocated may be different in the symbol region where PSCCH is transmitted and the symbol region where PSCCH is not transmitted. Fig.12 (b) to (d) of FIG. 1 show the time slot structure of the transmission area of ​​PSCCH (first SCI transmission) and S-PRS multiplexed in FDM. In this case, the frequency area allocated to PSCCH can be located at the bottom of the area where S-PRS is transmitted, and can occupy a fixed frequency area of ​​X RBs. In this case, X=2 RBs can be considered. However, in the present disclosure, the method for mapping PSCCH is not limited to Fig.12 The method of (b) to (d).

[0264] according to Fig.12 In (b), in the symbol region 1200 where the S-PRS can be transmitted, only two symbols with symbol indexes = 3 and 4 are selected and allocated to the S-PRS. Fig.12 In (c), in the symbol region 1200 where the S-PRS can be transmitted, 6 symbols with symbol indexes = 1 to 6 are selected and allocated for the S-PRS. Fig.12 In (d), in a symbol region 1200 where the S-PRS can be transmitted, 12 symbols with symbol indexes = 1 to 12 are selected and allocated for the S-PRS.

[0265] according to Fig.12 , the terminal can indicate the number and position information of S-PRS symbols currently sent through PSCCH (first SCI transmission) and S-PRS related parameter configuration information.

[0266] <Fourth Embodiment>

[0267] As described above, the following alternatives may be considered as the resource allocation method for positioning signal transmission described by the second embodiment.

[0268] -Alternative 1: Positioning signal transmission in the resource region where PSSCH is transmitted

[0269] -Alternative 2: Positioning signal transmission in dedicated resources different from the resource region where PSSCH is transmitted

[0270] The fourth embodiment provides a congestion control method according to the above alternative scheme.

[0271] When considering alternative scheme 1, positioning signal transmission is considered in the resource region where PSSCH is transmitted, so the congestion control method considered when transmitting PSSCH can be reused when considering positioning signals. In alternative scheme 1, the following cases can be considered when transmitting positioning signals.

[0272] - Case 1: Transmitting positioning signals and data together in the PSSCH region

[0273] - Case 2: Only positioning signals are transmitted in the PSSCH region

[0274] In the above, the positioning signal may include all positioning related information, such as a measurement report including S-PRS and location information transmission, or the positioning signal may be limited to S-PRS. When the positioning signal is limited to S-PRS, the positioning related information such as measurement report and location information transmission may be classified as data transmission.

[0275] In addition, depending on the type of positioning signal, the priority of the corresponding signal may be different. Specifically, the priority of S-PRS transmission, the priority of measurement report, and the priority of location information transmission can be determined separately. In addition, except for positioning related information, this may be different from the priority of general data sent through the existing PSSCH. Therefore, case 1 can be further subdivided into the following cases.

[0276] - Case 1-1: The positioning signal (S-PRS) and data (general data information, not positioning related information) are transmitted together in the PSSCH region

[0277] - Case 1-2: Transmitting positioning signal (S-PRS) and data (positioning related information) together in the PSSCH region

[0278] In the above cases 1-1 and 1-2, the positioning signal in the PSSCH region is limited to the S-PRS. In this case, data transmission can be classified into a case of positioning related information (case 1-2) and a case of non-positioning related information (case 1-1). For example, in cases 1-1 and 1-2, if Fig.12As shown in (b) to (c), S-PRS can be sent in some areas of the time slot, and data can be sent in other areas of the time slot. When congestion control is performed in case 1 (cases 1-1 and 1-2), the terminal can determine the transmission parameters based on the channel busy ratio (CBR) and priority. The sixth embodiment can be referred to for CBR measurement. The fifth embodiment can be referred to for transmission parameters.

[0279] When the terminal performs congestion control in Case 1 (Case 1-1 and 1-2), one of the following assumptions about priority may be considered. It should be noted that the priority assumption in the present disclosure is not limited to the following assumption.

[0280] - Assumption 1: Priority is assumed for data transmission. The corresponding priority may be determined by a higher layer of the terminal and may be mapped to the priority provided as the first SCI through the PSCCH.

[0281] - Assumption 2: Priority is assumed for the positioning signal (S-PRS). The corresponding priority may be determined by a higher layer of the terminal, and the corresponding priority may be provided to the SCI (first SCI) through the PSCCH. In the case indicated by the SCI, a new SCI format may be defined.

[0282] -Assumption 3: Assume that the priority is Max (the priority of the positioning signal (S-PRS), the priority of data transmission). The corresponding priority can be determined by the higher layer of the terminal, and the Max priority value can be provided as SCI (first SCI) through PSCCH. In the case of being indicated by SCI, a new SCI format can be defined.

[0283] -Assumption 4: Assume that the priority is Min (the priority of the positioning signal (S-PRS), the priority of data transmission). The corresponding priority can be determined by the higher layer of the terminal, and the Min priority value can be provided as SCI (first SCI) through PSCCH. In the case of being indicated by SCI, a new SCI format can be defined.

[0284] On the contrary, since case 2 is a case where only the positioning signal is transmitted in the PSSCH area, when performing congestion control, the terminal can determine the transmission parameter based on the CBR and the priority of the positioning signal. In addition, the corresponding priority can be determined by a higher layer of the terminal, and the corresponding priority can be provided as SCI (first SCI) through PSCCH. In the case of being indicated by SCI, a new SCI format can be defined.

[0285] In addition, since the positioning signal is transmitted in the resource region where the PSSCH is transmitted according to alternative scheme 1, case 2 may include the terminal receiving resource allocation for PSSCH transmission from the BS (mode 1), or the terminal allocating resources by direct sensing (mode 2). When the terminal performs PSSCH transmission, the following may occur. In addition, the terminal may determine whether case 2 can be performed according to the following situation.

[0286] - Case 1: The positioning signal (S-PRS) is sent only in the PSSCH region

[0287] The terminal may send a positioning signal (S-PRS) in the PSSCH region according to case 2. The priority of the positioning signal (S-PRS) may be determined by a higher terminal, and the corresponding priority may be provided to the SCI (first SCI) through the PSCCH. In addition, the corresponding priority may be used for congestion control.

[0288] - Case 2: Data (positioning related information) signals are sent only in the PSSCH region

[0289] The terminal can send data (positioning related information) in the PSSCH region. The priority of the data (positioning related information) can be determined by the higher layer of the terminal, and the corresponding priority can be provided to the SCI (first SCI) through the PSCCH. In addition, the corresponding priority can be used for congestion control.

[0290] - Case 3: Data (general data information, not positioning related information) signals are transmitted only in the PSSCH region

[0291] The terminal can send data (general data information, not positioning related information) in the PSSCH area. The priority of the data (general data information, not positioning related information) can be determined by the higher level of the terminal, and the corresponding priority can be provided to the SCI (first SCI) through the PSCCH. In addition, the corresponding priority can be used for congestion control.

[0292] - Case 4: To send positioning signal (S-PRS) and data (positioning related information) signal in the PSSCH region

[0293] The terminal may always prioritize the positioning signal (S-PRS), or may always prioritize the data (positioning related information) signal, or may select the signal based on the priority of the positioning signal (S-PRS) and the data (positioning related information) signal. The corresponding priority may be determined by the higher level of the terminal. In the case of priority, the terminal may determine the signal to be sent based on the higher priority value of the two signals. In addition, the priority of the signal to be sent may be provided to the SCI (first SCI) through the PSCCH. In addition, the corresponding priority may be used for congestion control.

[0294] - Case 5: Positioning signal (S-PRS) and data (general data information, non-positioning related information) signals to be transmitted in the PSSCH region

[0295] The terminal may always prioritize the positioning signal (S-PRS), or may always prioritize the data (general data information, non-positioning related information) signal, or may determine which signal to send based on the priority of the positioning signal (S-PRS) and the data (general data information, non-positioning related information). The corresponding priority may be determined by the high level of the terminal. In the case of priority, the terminal may determine the signal to be sent based on the higher priority value of the two signals. In addition, the priority of the signal to be sent may be provided to the SCI (first SCI) through the PSCCH. In addition, the priority may be used for congestion control.

[0296] - Case 6: Positioning signal (S-PRS) and data (positioning related information and general data information other than positioning related information) signals to be transmitted in the PSSCH region

[0297] The terminal may always prioritize the positioning signal (S-PRS), or may always prioritize the data (positioning related information) signal, or may always prioritize the data (general data information, non-positioning related information) signal, or may determine which signal to send based on the priority of the positioning signal (S-PRS), the data (positioning related information) signal, and other data (general data information, non-positioning related information) signals. The corresponding priority may be determined by the higher level of the terminal. In the case of priority, the terminal may determine the signal to be sent based on the higher priority value in the corresponding signal. In addition, the priority of the signal to be sent may be provided to the SCI (first SCI) via the PSCCH. In addition, the corresponding priority may be used for congestion control.

[0298] - Case 7: Data (positioning related information) signal and another data (general data information, non-positioning related information) signal to be transmitted in the PSSCH region

[0299] The terminal may always prioritize the data (positioning related information) signal, or may always prioritize the data (general data information, non-positioning related information) signal, or may determine which signal to send based on the priority of the data (positioning related information) signal and another data (general data information, non-positioning related information) signal. The corresponding priority may be determined by the higher level of the terminal. In the case of priority, the terminal may determine the signal to be sent based on the higher priority value of the two signals. In addition, the priority of the signal to be sent may be provided to the SCI (first SCI) via the PSCCH. In addition, the corresponding priority may be used for congestion control.

[0300] When positioning signal transmission is performed in a dedicated resource region in Alternative Scheme 2, the following detailed alternative schemes may be considered. However, the present disclosure is not limited to the following detailed alternative schemes.

[0301] -Alternative scheme 2-1: Not only S-PRS but also data (positioning related information) may be transmitted in the dedicated resource region.

[0302] -Alternative 2-2: Send only S-PRS in dedicated resource regions

[0303] In alternative 2-1, similar to alternative 1 (case 1-2), a congestion control method may be considered. In addition, when alternative 2-2 is considered, similar to alternative 1 (case 2, case 1), a congestion control method may be considered. In addition, when alternative 2 is considered, since positioning signal transmission is considered in a dedicated resource area different from the resource area for transmitting PSSCH, a congestion control method for positioning signal transmission may be defined separately. When performing congestion control, the terminal may determine transmission parameters based on CBR and the priority of the positioning signal. The sixth embodiment may be referenced for CBR measurement. The fifth embodiment may be referenced for transmission parameters.

[0304] <Fifth Embodiment>

[0305] The fifth embodiment includes a transmission parameter adjustment method according to a congestion control method for positioning signal transmission. The terminal can adjust whether to send a positioning signal and related transmission parameters considering the congestion of SL transmission. Specifically, S-PRS can be transmitted in a different time and frequency manner from PSSCH transmission, and therefore, the parameters for S-PRS transmission can be defined differently from PSSCH transmission.

[0306] When performing congestion control, the terminal can determine the transmission parameters based on CBR and priority. The sixth embodiment can be referenced for CBR measurement. The fourth embodiment can be referenced for priority. However, when priority is not used and only CBR is used, congestion control for SL positioning signals can also be considered.

[0307] Fig.13 A method for determining transmission parameters according to congestion control when sending a SL positioning signal according to an embodiment is shown.

[0308] refer to Fig.13 , a transmission parameter configuration range 1350 corresponding to a CBR range 1340, a CBR level 1330, and a priority 1320 of a signal to be transmitted may be (pre)configured through a resource pool configuration 1310. The corresponding values ​​may be pre-configured in the terminal before the terminal is connected to the BS, or may be configured from the BS through an SIB, or may be configured specifically for the terminal after an RRC connection with the BS. Optionally, the terminal may be configured through a PC5-RRC connection between the terminals.

[0309] The terminal may perform CBR measurement for congestion control. The CBR may be measured as a value between 0 and 100. The terminal may determine the CBR level 1330 by determining whether the measured CBR corresponds to the minimum / maximum value of the CBR range 1340. For example, Fig.13 In the example, CBR can be divided into a maximum of X=16 CBR levels. Therefore, for congestion control, the terminal can refer to the priority 1320 of the signal to be sent, the CBR level 1330, and the corresponding transmission parameter configuration range 1350. When the priority is not used for congestion control of the SL positioning signal and only CBR is used, the terminal can refer to the CBR level 1330 and the transmission parameter configuration range 1350 corresponding to the CBR level 1330.

[0310] Details of the configuration range 1350 of transmission parameters related to the SL positioning signal are described below.

[0311] CR Limit

[0312] The CR limit may refer to an upper limit of a channel occupancy ratio (CR). Here, CR is a measurement value indicating how many channels a terminal has occupied and how many channels the terminal plans to occupy. The seventh embodiment may be referenced for CR measurement. The terminal may measure CR and perform congestion control so that the corresponding measurement value is less than the CR limit. For example, for a congested channel (i.e., a case of a large CBR level), the CR limit may be configured to a smaller value. In addition, since the terminal has a higher priority, the CR limit may be configured to a larger value. In Fig.13For example, the corresponding value can be configured in the range of integers (0..10000).

[0313] CombSize

[0314] CombSize is the size of the S-PRS comb teeth. Figure 8 and Fig. 9 As described above, S-PRS can be sent in various comb sizes. The terminal can perform congestion control by adjusting CombSize. For example, for a congested channel (i.e., a large CBR level), CombSize can be configured to a smaller value. The smaller the CombSize, the higher the probability of S-PRS collision in a congested channel. Fig.13 For example, the corresponding value can be configured within the range of integers (2, 4, 6, 12).

[0315] SymbolLength

[0316] SymbolLength is the length of a symbol that can be allocated to S-PRS in one slot. Figure 8 and Fig. 9 As described above, S-PRS can be designed to have symbols of various lengths. The terminal can perform congestion control by adjusting SymbolLength. For example, for a congested channel (i.e., a large CBR level), SymbolLength can be configured to a smaller value. The larger the SymbolLength, the higher the probability of S-PRS collision in a congested channel. Fig.13 For example, the corresponding value can be configured within the range of integers (2, 4, 6, 12).

[0317] RBdensity

[0318] RBdensity is the density on the frequency at which the S-PRS is transmitted, and may indicate whether the S-PRS is transmitted per RB in a frequency region with a density of 1 in units of RBs, whether the S-PRS is transmitted per 2 RBs in a frequency region with a density of 1 / 2 in units of RBs, or whether the S-PRS is transmitted per 4 RBs in a frequency region with a density of 1 / 4 in units of RBs. The terminal may perform congestion control by adjusting the RBdensity. For example, for a congested channel (ie, a case of a large CBR level), RBdensity may be configured to a smaller value. The higher the RBdensity, the higher the probability of an S-PRS conflict in a congested channel. Fig.13 For example, the corresponding value can be configured in the range of (1, 1 / 2, 1 / 4).

[0319] MinBWSub-channelNum, MaxSub-channelNum

[0320] MinBWSub-channelNum and MaxSub-channelNum can respectively represent the minimum and maximum number of subchannels that can be allocated to S-PRS in one time slot. The terminal can perform congestion control by adjusting MinBWSub-channelNum and MaxSub-channelNum. For example, for a congested channel (i.e., a case of a large CBR level), the number of subchannels that can be allocated to S-PRS can be configured to a smaller value. The more the number of allocable subchannels, the higher the probability of S-PRS collision in a congested channel. Fig.13 For example, the corresponding value can be configured in the range of integers (1...27).

[0321] MaxTxRepetition

[0322] MaxTxRepetition can indicate the maximum value of S-PRS repetition, and S-PRS repetition can indicate that S-PRS is sent repeatedly in one or more time slots. The terminal can perform congestion control by adjusting MaxTxRepetition. For example, for congested channels (i.e., large CBR level), the value of MaxTxRepetition can be configured to a smaller value. As the S-PRS repetition value increases, the probability of S-PRS collision in a congested channel may increase. Fig.13 For example, the corresponding value can be configured in the range of integers (1...4).

[0323] MaxTxPower

[0324] MaxTxPower can indicate the maximum value of the S-PRS power. The terminal can perform congestion control by adjusting MaxTxPower. For example, for a congested channel (i.e., a large CBR level), the value of MaxTxPower can be configured to a smaller value. As the value of MaxTxPower increases, the probability of interference to the S-PRS in the congested channel may increase. Fig.13 For example, the corresponding value can be configured in the range of integers (-30...33).

[0325] <Sixth Embodiment>

[0326] A sixth embodiment includes a method for defining a CBR to perform congestion control for positioning signal transmission.

[0327] CBR is an index indicating how much of the current channel the terminal occupies, and can determine whether the corresponding channel of the SL is congested. The terminal can determine whether the corresponding channel is congested by measuring the CBR value according to the CBR definition as described below. The terminal can report the measured CBR to the BS. Specifically, when the BS and the terminal are connected through Uu-RRC, the CBR value measured by the terminal can be reported to the BS through Uu-RRC.

[0328] Although a scenario of measuring the CBR based on an SL received signal strength indicator (RSSI) and a scenario of measuring the CBR based on an S-PRS are described below, the present disclosure is not limited thereto.

[0329] Measuring CBR based on SL RSSI

[0330] When the CBR is measured based on the SL RSSI, the CBR measured in time slot n may be defined as follows.

[0331] The CBR may be defined as the ratio of subchannels in the resource pool whose SL RSSI measured by the terminal exceeds a (pre-)configured threshold. Here, the CBR measurement may be performed in time slots [nX, n-1]. The time slot index may be based on the physical time slot index.

[0332] X represents the window value for measuring CBR, and the value of X can be a fixed value or a configurable value. For example, the value of X can be a fixed value of 100 time slots or 100·2 determined according to SCSμ. μ However, in the present disclosure, the method for determining the X value, that is, the method for determining the CBR measurement window is not limited to a specific method.

[0333] SL RSSI is the received signal strength and can indicate how much power (in [W]) is received from the terminal. Fig.12 As shown in (a), the SL RSSI can be defined as the average received power observed in symbols corresponding to the PSCCH and PSSCH regions of the OFDM symbol and the corresponding subchannel after the AGC symbol.

[0334] Measuring CBR for S-PRS (Method 1)

[0335] When measuring CBR for S-PRS, the CBR measured in time slot n may be defined as follows.

[0336] The CBR may be defined as the ratio of subchannels transmitting S-PRS where the SLPRS-RSSI measured by the terminal in the resource pool exceeds a (pre)configured threshold. The CBR measurement may be performed in time slots [nX, n-1]. The time slot index may be based on the physical time slot index.

[0337] X represents the window value for measuring CBR, and the value of X can be a fixed value or a configurable value. For example, the value of X can be a fixed value of 100 time slots or 100·2 determined according to SCSμ. μ However, in the present disclosure, the method for determining the X value, that is, the method for determining the CBR measurement window is not limited to a specific method.

[0338] SL PRS-RSSI is the received signal strength of the S-PRS and may indicate the power (in [W]) of the S-PRS received from the terminal. Fig.12 As shown in (b) to (c), SL RSSI can be defined as the average S-PRS received power observed in the OFDM symbol and the corresponding subchannel region where the S-PRS is transmitted. In this case, SL PRS-RSSI can be replaced by other terms.

[0339] Measuring CBR for S-PRS (Method 2)

[0340] When measuring CBR for S-PRS, the CBR measured in time slot n may be defined as follows.

[0341] CBR may be defined as the ratio of RBs transmitting S-PRS where the SL PRS-RSSI measured by the terminal in the resource pool exceeds a (pre)configured threshold. CBR measurements may be performed in time slots [nX, n-1] and the time slot index may be based on the physical time slot index.

[0342] X represents the window value for measuring CBR, and the value of X can be a fixed value or a configurable value. For example, the value of X can be a fixed value of 100 time slots or 100·2 determined according to SCSμ. μ However, in the present disclosure, the method for determining the X value, that is, the method for determining the CBR measurement window is not limited to a specific method.

[0343] SL PRS-RSSI is the received signal strength of the S-PRS and may indicate the power (in [W]) of the S-PRS received from the terminal. Fig.12 As shown in (b) to (c), SL RSSI can be defined as the average S-PRS received power observed in the OFDM symbol and corresponding RB region where the S-PRS is transmitted. In this case, SL PRS-RSSI can be replaced by other terms.

[0344] Measuring CBR for S-PRS (Method 3)

[0345] When measuring CBR for S-PRS, the CBR measured in time slot n may be defined as follows.

[0346] CBR can be defined as the ratio of resource elements (REs) transmitting S-PRS where the SL PRS-RSSI measured by the terminal in the resource pool exceeds a (pre)configured threshold. Here, CBR measurement can be performed in time slots [nX, n-1], and the time slot index can be based on the physical time slot index.

[0347] X represents the window value for measuring CBR, and the value of X can be a fixed value or a configurable value. For example, the value of X can be a fixed value of 100 time slots or 100·2 determined according to SCSμ. μ However, in the present disclosure, the method for determining the X value, that is, the method for determining the CBR measurement window is not limited to a specific method.

[0348] SL PRS-RSSI is the received signal strength of the S-PRS and may indicate the power (in [W]) of the S-PRS received from the terminal. Fig.12 As shown in (b) to (c), SL RSSI can be defined as the average S-PRS received power observed in the OFDM symbol and corresponding RE region where the S-PRS is transmitted. In this case, SL PRS-RSSI can be replaced by other terms.

[0349] <Seventh Embodiment>

[0350] The seventh embodiment includes a method for defining a CR to perform congestion control for positioning signal transmission.

[0351] CR may be a measurement indicating how many channels the terminal has occupied and how many channels the terminal plans to occupy. The terminal may measure CR and perform congestion control so that the measured value is less than the CR limit. When the CR limit is not met, that is, when the measured value is greater than the CR limit, the corresponding transmission may be discarded, or other transmission parameters may be adjusted by the terminal implementation to meet the CR limit.

[0352] When CR is measured for data transmitted in the PSSCH region and when CR is measured for the S-PRS, the CR may be defined differently.

[0353] CR is measured for data sent in the PSSCH region

[0354] When CR is measured for data transmitted in the PSSCH region, the CR measured in slot n may be defined as follows.

[0355] CR may be defined as a value obtained by dividing the sum of the number of subchannels occupied and used by the terminal at the time of time slot [na, n-1] and the number of subchannels that the terminal is allowed to occupy and use at the time of time slot [n, n+b] by the total number of subchannels configured in the transmission resource pool at the time of time slot [na, n+b]. The time slot index may be based on the physical time slot index.

[0356] Here, a is a positive integer, and b is 0 or a positive integer. In addition, the values ​​of a and b are fixed values ​​such as a+b+1=1000 time slots, or a+b+1=1000·2 determined by SCSμ. μ The value of a time slot and b<(a+b+1) / 2 can be achieved by the terminal. In addition, n+b cannot be configured to exceed the value of the last transmission opportunity allowed by the transmission resource reservation. However, in the present disclosure, the method for determining the value of a or b, that is, the method for determining the CR measurement window is not limited to a specific method.

[0357] Measuring CR for S-PRS

[0358] When measuring CR for S-PRS, the CR measured in slot n may be defined as follows.

[0359] Method 1: CR may be defined as a value obtained by dividing the sum of the number of S-PRS subchannels occupied and used by the transmitting terminal at the time of time slot [na, n-1] and the number of S-PRS subchannels that the transmitting terminal is allowed to occupy and use at the time of time slot [n, n+b] by the total number of subchannels configured in the transmission resource pool at the time of time slot [na, n+b]. The time slot index may be based on the physical time slot index.

[0360] Method 2: CR may be defined as a value obtained by dividing the sum of the number of S-PRS RBs occupied and used by the transmitting terminal at the time of time slot [na, n-1] and the number of S-PRS RBs of the channel that the transmitting terminal is allowed to occupy and use at the time of time slot [n, n+b] by the total number of RBs configured in the transmission resource pool at the time of time slot [na, n+b]. The time slot index may be based on the physical time slot index.

[0361] Method 3: CR may be defined as a value obtained by dividing the sum of the number of S-PRS REs occupied and used by the transmitting terminal at the time of time slot [na, n-1] and the number of S-PRS REs of the channel that the transmitting terminal is allowed to occupy and use at the time of time slot [n, n+b] by the total number of REs configured in the transmission resource pool at the time of time slot [na, n+b]. The time slot index may be based on the physical time slot index.

[0362] Here, a is a positive integer, and b is 0 or a positive integer. In addition, the values ​​of a and b are fixed values ​​such as a+b+1=1000 time slots, or A+b+1=1000·2 determined by SCSμ. μ The value of a time slot and b<(a+b+1) / 2 can be achieved by the terminal. In addition, n+b cannot be configured to exceed the value of the last transmission opportunity allowed by the transmission resource reservation. However, in the present disclosure, the method for determining the value of a or b, that is, the method for determining the CR measurement window is not limited to a specific method.

[0363] Fig.14 is a flowchart illustrating the operation of a terminal according to an embodiment.

[0364] For example, the following may be performed based on at least one of the above embodiments: Fig.14 In addition, you can omit Fig.14 Some operations may be combined or two or more steps may be performed as one step. In addition, Fig.14 order.

[0365] refer to Fig.14 In step 1401, the terminal may obtain information about transmission parameters associated with the S-PRS.

[0366] For example, information about transmission parameters can be configured based on the fifth embodiment. The transmission parameters may include at least one of a comb size associated with the S-PRS and the number of symbols used for the S-PRS in a time slot. The transmission parameters may also include at least one of the following: (i) RB density in the frequency domain, (ii) the minimum number of subchannels used for the S-PRS in a time slot, (iii) the maximum number of subchannels used for the S-PRS in a time slot, (iv) the maximum number of transmissions for the S-PRS, or (v) the maximum transmission power for the S-PRS.

[0367] For example, the comb size may be configured to be one of 2, 4, 6, or 12, and the number of symbols used for S-PRS in a slot may be configured to be one of 2, 4, 6, or 12.

[0368] In step 1402, the terminal may identify a resource pool associated with an S-PRS.

[0369] For example, the resource pool associated with the S-PRS may be identified based on the second embodiment or the third embodiment.For example, the resource pool associated with the PSSCH in the time domain may not overlap with the resource pool associated with the S-PRS.

[0370] In step 1403, the terminal may perform measurement based on the resource pool associated with the S-PRS. The measurement may be a measurement of the CBR or a measurement of the CR. The CBR measured in the time slot may be defined based on the sixth embodiment. The CR measured in the time slot may be defined based on the seventh embodiment.

[0371] In step 1404, the terminal may determine at least one transmission parameter associated with the S-PRS based on the information about the transmission parameter and the measurement. For example, the at least one transmission parameter may be determined based on the second embodiment and / or the fifth embodiment. In addition, when the priority of the S-PRS and the data is used when determining the at least one transmission parameter, the fourth embodiment may be further considered.

[0372] Despite Fig.14 Although not shown in the figure, the terminal may transmit information including the measurement result to the BS. The BS may perform congestion control associated with the S-PRS based on the information.

[0373] Fig.15 A terminal according to an embodiment is shown.

[0374] refer to Fig.15 , the terminal includes a receiver 1500, a transmitter 1504, and a processor 1502. The receiver 1500 and the transmitter 1504 may be generally referred to as a transceiver. The transceiver may send a signal to the BS and receive a signal from the BS. The signal may include control information and data. To this end, the transceiver may include a radio frequency (RF) transmitter that up-converts and amplifies the frequency of the transmitted signal, an RF receiver that performs low-noise amplification on the received signal and down-converts the frequency, etc. In addition, the transceiver may receive a signal through a wireless channel, output the signal to the processor 1502, and transmit the signal output from the processor 1502 through the wireless channel.

[0375] The processor 1502 may control a series of processes so that the terminal operates according to the embodiments of the present disclosure. For example, the processor 1502 may control the terminal to perform positioning operations in the SL according to the above embodiments of the present disclosure.

[0376] Fig.16 A BS according to an embodiment is shown.

[0377] refer to Fig.16, the BS includes a receiver 1601, a transmitter 1605, and a processor 1603. The receiver 1601 and the transmitter 1605 may be generally referred to as a transceiver. The transceiver may send and receive signals to and from a terminal. The signal may include control information and data. To this end, the transceiver may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, an RF receiver that performs low-noise amplification on a received signal and down-converts the frequency, and the like. In addition, the transceiver may receive a signal through a wireless channel, output the signal to the processor 1603, and transmit the signal output from the processor 1603 through a wireless channel.

[0378] The processor 1603 may control a series of processes so that the BS operates according to the embodiments of the present disclosure. For example, the processor 1603 may control the operation of the BS for terminal positioning measurement in the SL according to the above embodiments of the present disclosure.

[0379] The above-mentioned embodiments and drawings of the present disclosure are presented only as specific examples to easily explain the technical content of the present disclosure and help understand the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other modified examples based on the technical spirit of the present disclosure can be implemented. In addition, each embodiment can be combined with each other as needed. For example, parts of all embodiments of the present disclosure can be combined with each other to operate BS and terminals.

[0380] According to the above-mentioned embodiments, the terminal can perform positioning (eg, position measurement) through the SL, and the positioning accuracy can be improved.

[0381] In addition, according to the above-described embodiment, the terminal can perform congestion control when performing positioning through SL.

[0382] While the present disclosure has been described with reference to various embodiments, various changes may be made without departing from the spirit and scope of the present disclosure, which is defined not by the detailed description and embodiments but by the appended claims and their equivalents.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: obtaining information about transmission parameters associated with a sidelink (SL) positioning reference signal; Identifying a resource pool associated with a SL positioning reference signal; performing measurements based on a resource pool associated with a SL positioning reference signal; and determining at least one transmission parameter associated with the SL positioning reference signal based on the measurement and the information about the transmission parameter, The transmission parameters include at least one of a comb tooth size associated with the SL positioning reference signal and the number of symbols used for the SL positioning reference signal in a time slot.

2. The method according to claim 1, wherein: The transmission parameters also include at least one of the resource block density in the frequency domain, the minimum number of subchannels for SL positioning reference signals in a time slot, the maximum number of subchannels for SL positioning reference signals in a time slot, the maximum transmission number of SL positioning reference signals, and the maximum transmission power of SL positioning reference signals.

3. The method according to claim 1, wherein: The comb size is configured to a value of 2, 4, 6, or 12, and Therein, the number of symbols is configured to be a value of 2, 4, 6, or 12.

4. The method according to claim 1, wherein: The measurements include measurements of the channel busy ratio (CBR) or measurements of the channel occupancy ratio (CR).

5. The method according to claim 4, wherein: The CBR measured in a time slot is defined as the portion of subchannels in the resource pool whose received signal strength indicator (RSSI) of the SL positioning reference signal measured by the terminal exceeds a threshold sensed over the CBR measurement window.

6. The method according to claim 4, wherein: The CR in time slot n is defined as the total number of subchannels used for SL positioning reference signal transmission in time slot [na, n-1] and permitted in time slot [n, n+b] divided by the total number of subchannels in the resource pool configured on [na, n+b], where a is a positive integer, b is 0 or a positive integer, and (a+b+1=1000).

7. The method according to claim 1, further comprising: Information including the results of the measurements is sent to the base station.

8. The method according to claim 1, wherein: The resource pool associated with the SL positioning reference signal and the resource pool associated with the physical SL shared channel (PSSCH) do not overlap in the time domain.

9. A terminal, comprising: Transceiver; as well as A controller is coupled to the transceiver and is configured to: obtaining information about transmission parameters associated with a sidelink (SL) positioning reference signal, identifying a resource pool associated with the SL positioning reference signal, performing measurements based on a resource pool associated with the SL positioning reference signal, and determining at least one transmission parameter associated with the SL positioning reference signal based on the measurement and the information about the transmission parameter, The transmission parameters include at least one of a comb tooth size associated with the SL positioning reference signal and the number of symbols used for the SL positioning reference signal in a time slot.

10. The terminal according to claim 9, wherein: The transmission parameters also include at least one of the resource block density in the frequency domain, the minimum number of subchannels for SL positioning reference signals in a time slot, the maximum number of subchannels for SL positioning reference signals in a time slot, the maximum transmission number of SL positioning reference signals, and the maximum transmission power of SL positioning reference signals.

11. The terminal according to claim 9, wherein: The comb size is configured to a value of 2, 4, 6, or 12. where the number of symbols is configured to be a value of 2, 4, 6, or 12, and Among them, the resource pool associated with the SL positioning reference signal and the resource pool associated with the physical SL shared channel (PSSCH) do not overlap in the time domain.

12. The terminal according to claim 9, wherein: The measurements include measurements of the channel busy ratio (CBR) or measurements of the channel occupancy ratio (CR).

13. The terminal according to claim 12, wherein: The CBR measured in a time slot is defined as the portion of subchannels in the resource pool whose received signal strength indicator (RSSI) of the SL positioning reference signal measured by the terminal exceeds a threshold sensed over the CBR measurement window.

14. The terminal according to claim 12, wherein: The CR in time slot n is defined as the total number of subchannels used for SL positioning reference signal transmission in time slot [na, n-1] and permitted in time slot [n, n+b] divided by the total number of subchannels in the resource pool configured on [na, n+b], where a is a positive integer, b is 0 or the positive integer, and (a+b+1=1000).

15. The terminal according to claim 9, wherein: The controller is further configured to send information including the result of the measurement to the base station.

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