Reference signal transmission alignment mechanism

Abstract

The invention relates to reference signal transmission alignment. In particular, a target device determines whether reference signal transmission alignment is required between a set of anchor devices. If reference signal transmission alignment is needed, the anchoring device receives a request for reference signal transmission alignment. The anchoring device determines a transmission time window based on the request and transmits a reference signal according to the transmission time window. This may mitigate the effects of synchronization timing reference variations at the target device in the measurement. Therefore, the solution can realize high-precision measurement, thereby realizing high-precision side link positioning.

Description

Technical Field

[0001] Various example embodiments of the present disclosure relate generally to the field of telecommunications, and in particular, to methods, devices, apparatuses, and computer-readable storage media for reference signal transmission alignment. Background Art

[0002] Location awareness is a fundamental aspect of wireless communication networks, which will support a large number of location-supported services in different applications. As the accuracy of the technology improves, the integration and utilization of location information in daily applications will grow significantly. Many positioning techniques that rely on techniques such as time of arrival (TOA), time difference of arrival (TDOA), and angle of arrival (AOA) require line-of-sight (LOS) propagation between a reference point (e.g., network equipment) and the mobile device to be located. In some cases, the user equipment (UE) can facilitate the positioning of the device. Therefore, sidelink (SL) positioning deserves investigation. Public Content

[0003] In a first aspect of the present disclosure, a device is provided. The device includes: at least one processor; and at least one memory storing instructions, wherein when the instructions are executed by the at least one processor, the device: receives a request for reference signal transmission alignment for triggering reference signal transmission alignment with a set of devices, wherein the device and the set of devices are participating in a positioning session with a target device; based on the request for reference signal transmission alignment, determines a transmission time window for reference signal transmission alignment; and sends a reference signal to at least the target device according to the transmission time window.

[0004] In a second aspect of the present disclosure, a device is provided. The device includes: at least one processor; and at least one memory storing instructions, wherein when the instructions are executed by the at least one processor, the device: determines whether reference signal transmission alignment between a set of devices is required, wherein the set of devices is participating in a positioning session with the device; receives a reference signal from at least one device in the set of devices according to a transmission time window determined by at least one device based on a request for reference signal transmission alignment; and performs measurement using the received reference signal.

[0005] In a third aspect of the present disclosure, a device is provided. The device includes: at least one processor; and at least one memory storing instructions, wherein when the instructions are executed by the at least one processor, the device: receives information indicating that reference signal transmission alignment is required between a set of devices from a device, wherein the set of devices is participating in a positioning session with the device; and sends a request for reference signal transmission alignment to the set of devices, for triggering the reference signal transmission alignment.

[0006] In a fourth aspect of the present disclosure, a method is provided. The method includes: receiving a request for reference signal transmission alignment for triggering reference signal transmission alignment with a device set, wherein the device and the device set are participating in a positioning session with a target device; determining a transmission time window for reference signal transmission alignment based on the request for reference signal transmission alignment; and sending a reference signal to at least the target device according to the transmission time window.

[0007] In a fifth aspect of the present disclosure, a method is provided. The method includes: determining whether reference signal transmission alignment between a set of devices is required, wherein the set of devices is participating in a positioning session with an apparatus; receiving a reference signal from at least one device in the set of devices according to a transmission time window determined by at least one device based on a request for reference signal transmission alignment; and performing measurement using the received reference signal.

[0008] In a sixth aspect of the present disclosure, a method is provided. The method includes: receiving information from a device indicating that reference signal transmission alignment is required between a set of devices, wherein the set of devices is participating in a positioning session with the device; and sending a request for reference signal transmission alignment to the set of devices for triggering the reference signal transmission alignment.

[0009] In a seventh aspect of the present disclosure, a first device is provided. The first device includes a component for receiving a request for reference signal transmission alignment, for triggering the reference signal transmission alignment with a set of devices, wherein the first device and the set of devices are participating in a positioning session with a target device; a component for determining a transmission time window for reference signal transmission alignment based on the request for reference signal transmission alignment; and a component for transmitting a reference signal to at least the target device according to the transmission time window.

[0010] In an eighth aspect of the present disclosure, a second device is provided. The second device includes: a component for determining whether reference signal transmission alignment between a set of devices is required, wherein the set of devices is participating in a positioning session with a second device; a component for receiving a reference signal from at least one device in the set of devices according to a transmission time window determined by at least one device based on a request for reference signal transmission alignment; and a component for performing measurement using the received reference signal.

[0011] In a ninth aspect of the present disclosure, a third apparatus is provided. The third apparatus includes: a component for receiving information indicating that reference signal transmission alignment is required between a set of devices from a device, wherein the set of devices is participating in a positioning session with the device; and a component for sending a request for reference signal transmission alignment to the set of devices for triggering the reference signal transmission alignment.

[0012] In a tenth aspect of the present disclosure, a computer-readable medium is provided, wherein the computer-readable medium includes instructions stored thereon, and is used to cause a device to at least execute the method according to the fourth aspect.

[0013] In an eleventh aspect of the present disclosure, a computer-readable medium is provided, wherein the computer-readable medium includes instructions stored thereon, and is used to cause a device to at least execute the method according to the fifth aspect.

[0014] In a twelfth aspect of the present disclosure, a computer-readable medium is provided, wherein the computer-readable medium includes instructions stored thereon, and is used to cause a device to at least execute the method according to the sixth aspect.

[0015] It should be understood that the disclosure part is not intended to identify the key or essential features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0017] Figure 1 An example communication environment is shown in which example embodiments of the present disclosure may be implemented;

[0018] Figure 2 A signaling diagram illustrating reference signal transmission alignment according to an example embodiment of the present disclosure;

[0019] Figure 3A and Figure 3B Schematic diagrams of synchronization search opportunities according to example embodiments of the present disclosure are respectively shown;

[0020] Figure 4A and Figure 4B Schematic diagrams of transmission time windows according to example embodiments of the present disclosure are respectively shown;

[0021] Figure 5 A flowchart showing a method implemented at an anchor device according to some example embodiments of the present disclosure is shown;

[0022] Figure 6 A flowchart of a method implemented at a target device according to some example embodiments of the present disclosure is shown;

[0023] Figure 7 A flowchart showing a method implemented at a device according to some example embodiments of the present disclosure is shown;

[0024] Figure 8 shows a simplified block diagram of a device suitable for implementing an example embodiment of the present disclosure; and

[0025] Fig. 9 A block diagram of an example computer-readable medium is shown according to some example embodiments of the present disclosure.

[0026] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0027] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described only for illustrative purposes to help those skilled in the art understand and implement the present disclosure without limiting the scope of the present disclosure. The embodiments described herein can be implemented in various ways except for the ways described below.

[0028] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0029] References in this disclosure to "one embodiment," "an embodiment," "an example embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment must include the particular feature, structure, or characteristic. Furthermore, these phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is within the knowledge of those skilled in the art to affect such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0030] It should be understood that although the terms "first", "second", etc. in front of nouns may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element and do not limit the order of the nouns. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the exemplary embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0031] As used herein, “at least one of: ” and “at least one of ” and similar expressions, where a list of two or more elements is connected by “and” or “or”, mean at least any one element, or at least any two or more elements, or at least all elements.

[0032] As used herein, unless explicitly stated, performing a step "in response to A" does not identify performing the step immediately after "A" occurs and may include one or more intermediate steps.

[0033] The terms used herein are used only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments. As used herein, the singular forms "a", "an", and "this" are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprises", "comprising", "has", "having", "includes", and / or "including", when used herein, specify the presence of stated features, elements, and / or components, etc., but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0034] As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) pure hardware circuit implementation (e.g., implementation in analog and / or digital circuits only) and (b) a combination of hardware circuitry and software, such as (where applicable): (i) a combination of analog and / or digital hardware circuitry and software / firmware, and (ii) a hardware processor (including a digital signal processor) with software, software and any portion of memory that work together to enable a device (such as a mobile phone or server) to perform various functions, and (c) Hardware circuits and / or processors, such as a microprocessor or portion of a microprocessor, that require software (such as firmware) to operate, but the software may not be present when not required for operation.

[0035] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term "circuitry" also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0036] As used herein, the term "communication network" refers to a network that complies with any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), Advanced LTE (LTE-A), Wideband Code Division Multiple Access (WCDMA), High Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. In addition, the communication between the terminal equipment and the network equipment in the communication network can be carried out according to any suitable generation of communication protocols, including but not limited to the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), sixth generation (6G) communication protocols and / or any other currently known or future to be developed protocols. The embodiments of the present disclosure can be applied to various communication systems. In view of the rapid development of communication, there will certainly be communication technologies and systems that can embody future types of the present disclosure. It should not be regarded as limiting the scope of the present disclosure to the aforementioned systems.

[0037] As used herein, the term "network device" refers to a node in a communication network, via which a terminal device accesses the network and receives services from the network. A network device may refer to a base station (BS) or an access point (AP), such as a NodeB (NodeB or NB), an evolved NodeB (eNodeB or eNB), a NR NB (also referred to as a gNB), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, an integrated access and backhaul (IAB) node, a low-power node (e.g., a femto, a micro), a non-terrestrial network (NTN) or a non-terrestrial network device (e.g., a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, etc.), depending on the terms and technologies applied. In some example embodiments, a radio access network (RAN) separation architecture includes a centralized unit (CU) and a distributed unit (DU) at an IAB donor node. An IAB node includes a mobile terminal (IAB-MT) portion that behaves similarly to a UE toward a parent node, and the DU portion of the IAB node behaves similarly to a base station toward a next-hop IAB node.

[0038] The term "terminal device" refers to any terminal device capable of wireless communication. As an example and not limitation, the terminal device may also be referred to as a communication device, a user equipment (UE), a subscriber station (SS), a portable subscriber station, a mobile station (MS) or an access terminal (AT). The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet computer, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image acquisition terminal device (e.g., a digital camera), a game terminal device, a music storage and playback device, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, an embedded notebook device (LEE), an installed notebook device (LME), a USB dongle, a smart device, a wireless client device (CPE), an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical equipment and applications (e.g., remote surgery), industrial equipment and applications (e.g., robots and / or other wireless devices running in industrial and / or automated processing chain environments), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to the mobile terminal (MT) part of an IAB node (eg, a relay node).In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

[0039] As used herein, the terms "resource", "transmission resource", "resource block", "physical resource block" (PRB), "uplink resource" or "downlink resource" may refer to any resource used to perform communication, for example, communication between a terminal device and a network device, such as time domain resources, frequency domain resources, space domain resources, code domain resources, or any combination of time, frequency, space and / or code domain resources for implementing communication. In the following, unless explicitly stated, some example embodiments of the present disclosure are described using frequency domain and time domain resources as examples of transmission resources. It should be noted that the example embodiments of the present disclosure are also applicable to other resources in other fields.

[0040] As used herein, the term "target terminal device / target UE" refers to a terminal device to be located. The term "anchor terminal device / anchor UE" may refer to a terminal device that supports the positioning of a target terminal device. For example, an anchor terminal device may send and / or receive reference signals for positioning via a side link interface (e.g., a PC5 interface). The anchor terminal device may also provide positioning-related information. The functionality of an anchor UE (i.e., an anchor node) may be similar to uplink / downlink (UL / DL)-based positioning, where the gNB serves as an anchor that sends reference signals to / receives reference signals from a target UE for positioning.

[0041] The term "sidelink positioning" used herein may preferably refer to the use of a reference signal sent via the SL (i.e., PC5 interface) to locate a terminal device to obtain an absolute position, a relative position, or ranging information. The term "ranging" used herein may refer to the determination of the distance and / or direction between a terminal device and another entity (e.g., an anchor UE). The term "sidelink (SL) positioning reference signal (PRS)" used herein may refer to a reference signal sent on the SL for positioning purposes. The term "SL PRS configuration" used herein may refer to a set of configuration parameters for the SL PRS, such as time-frequency resources including its bandwidth and periodicity, and direction-related parameters (e.g., beam direction, beam width, and number of beams). The SL PRS (pre) configuration may also refer to (pre) configured parameters of the SL PRS, such as transmit power. In addition, the SL PRS configuration in coverage or partial coverage may be determined by the network (e.g., by a location management function (LMF) or a gNB), and may be autonomously pre-configured and / or determined by the UE outside of coverage. SL synchronization considerations during anchor UE selection may also involve roadside units (RSUs), where UE type or gNB type fixed infrastructure entities support vehicle-to-everything V2X applications. Absolute positioning may refer to estimating the position of a UE in 2D / 3D geographic coordinates (e.g., latitude, longitude, altitude) within a coordinate system. Additionally, relative positioning may refer to an estimate of the position relative to other network elements or relative to other UEs.

[0042] The term "reference signal transmission alignment" as used herein may refer to a mechanism for adjusting the transmission of reference signals relative to each other to achieve simultaneous transmission of reference signals. The term "positioning session" as used herein may refer to a connection / connectivity for positioning a device. The term "transmission time window" as used herein may refer to a time domain resource for sending and / or receiving signals.

[0043] The technical specifications of the Third Generation Partnership Project (3GPP) consider SL positioning in situations such as V2X, public safety, and commercial and industrial Internet of Things (IIoT). In addition, 3GPP also considers scenarios and requirements for NR positioning use cases in coverage, partial coverage, and out-of-coverage, with a focus on V2X and public safety use cases. SA1 has established requirements for ranging-based services in 3GPP and positioning accuracy requirements for IIoT use cases in out-of-coverage scenarios. Positioning requirements can be captured through key performance indices (KPIs). For example, KPIs may include horizontal and vertical accuracy, where vertical accuracy refers to height accuracy and determines the floor for indoor use cases and distinguishes between superimposed tracks (e.g., bridges) for road and rail use cases. KPIs may also include positioning service availability, which corresponds to a percentage value of the amount of time that the positioning service transmits the required location-related data within the performance requirements divided by the amount of time the system expects to transmit the positioning service according to the specifications in the target service area. KPIs may also include positioning service latency, which corresponds to the time elapsed between the determined event that triggers the location-related data and the availability of the location-related data at the system interface. Additionally, the KPI may include a fixed time (TTFF) corresponding to the amount of time that elapses between a determined event that first triggers location-related data and the availability of the location-related data at the location system interface. The KPI may also include update rate and energy consumption parameters.

[0044] SL positioning is based on SL PRS sent by multiple anchor UEs for reception by target UEs, for example in SL TDOA method, or SLPRS exchange between anchor and target UEs, for example in SL (multi)RRT method, to enable positioning of target UE relative to a reference UE (e.g. anchor UE) and / or ranging of target UE within the precise delay and accuracy requirements of corresponding SL positioning.

[0045] In SL positioning, the UE can perform SL synchronization to obtain the SL timing reference by synchronizing with a synchronization reference (SyncRef) source. In some cases, if the gNB / eNB or Global Navigation Satellite System (GNSS) is not available as a SyncRef source, the UE can select SyncRef UE as the SyncRef source. Due to the distributed nature of SyncRef selection, different UEs can select different SyncRef sources in SL positioning scenarios.

[0046] In a DL-like SL TDOA approach, the target UE monitors the SL PRS transmitted by the anchor UE. In this case, the arrival time difference of the PRS relative to a reference time is measured for position estimation. In the case where the anchor UE does not transmit the SL PRS simultaneously, changes in the target UE's SyncRef source during measurements from different anchors may lead to inaccurate SL RSTD measurements.

[0047] Typically, a UE cannot schedule another UE. Therefore, with UE autonomous scheduling, for example in out-of-coverage scenarios (called Scheme 2 resource allocation, which is based on NR SL resource allocation Mode 2), simultaneous transmission of SL PRS cannot be ensured. Therefore, in SLTDOA-based positioning, if there is a SyncRef change at the target UE during SL RSTD measurements from different anchor UEs, the quality of the SL RSTD measurements and therefore the positioning accuracy is prone to degradation. Therefore, a solution for reference signal transmission alignment is needed. Example Environment

[0048] Figure 1 An example communication environment 100 is shown in which example embodiments of the present disclosure may be implemented. In the communication environment 100, there is a terminal device 110. The terminal device 110 may be, for example, a mobile phone or a vehicle. The communication environment 100 includes a set of terminal devices 120-1, 120-2, ..., 120-N (collectively referred to as "terminal devices 120"), where N may be an integer. It should be noted that the set of terminal devices 120 may include any appropriate number of terminal devices. The communication environment 100 also includes a device 130, which may be a server terminal device or a network node (e.g., a location management function (LMF) node). As shown in FIG. Figure 1 As shown, there may be one or more synchronization reference devices, such as device 140-1 and device 140-2. For example, device 140-1 may be a current synchronization reference device of device 110, and device 140-2 may be a candidate synchronization reference device of device 110.

[0049] Below, for the purpose of illustration, some example embodiments are described with terminal device 110 operating as a target device and terminal device 120 operating as an anchor device. However, in some example embodiments, the operations described in conjunction with the target device may be implemented at the anchor device, and the operations described in conjunction with the anchor device may be implemented at the target device. Hereinafter, terminal device 110 may be referred to as "target device 110", and terminal device 120 may be referred to as "anchor device 120".

[0050] In some example embodiments, the link between the target device 110 and the anchor device 120 is referred to as a side link (SL), and the link between the anchor devices is also referred to as a side link. In some example embodiments, the anchor device 120 is a transmit (TX) device (or transmitter) and the target device 110 is a receive (RX) device (or receiver). In some other example embodiments, the target device 110 is a TX device (or transmitter) and the anchor device 120 is an RX device (or receiver). It should be understood that Figure 1 The number of devices and their connections shown in are for illustration purposes only and do not represent any limitation.Communication environment 100 may include any suitable number of devices configured to implement example embodiments of the present disclosure.

[0051] The communication in the communication environment 100 can be implemented according to any appropriate communication protocol, including but not limited to cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G), the sixth generation (6G), etc., wireless local area network communication protocols such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11, and / or any other protocol currently known or developed in the future. In addition, the communication can utilize any appropriate wireless communication technology, including but not limited to: code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), frequency division duplex (FDD), time division duplex (TDD), multiple input multiple output (MIMO), orthogonal frequency division multiplexing (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM) and / or any other technology currently known or to be developed in the future. How communications work and example signaling

[0052] According to some example embodiments of the present disclosure, a solution for reference signal transmission alignment is provided. Specifically, the target device determines whether reference signal transmission alignment is required between anchor devices. If reference signal transmission alignment is required, the anchor device receives a request for reference signal transmission alignment. The anchor device determines a transmission time window based on the request, and sends a reference signal according to the transmission time window. In this way, the impact of changes in the synchronization timing reference at the target device in the measurement can be mitigated. Therefore, the solution can achieve high-precision measurement, thereby achieving high-precision side link positioning.

[0053] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Figure 2 , which shows a signaling flow 200 for reference signal transmission alignment according to some example embodiments of the present disclosure. For the purpose of discussion, reference Figure 1The signaling flow 200 is discussed, for example, by using the target device 110 , the anchor device 120 - 1 , the anchor device 120 - 2 , and the device 130 .

[0054] The anchor devices 120 (e.g., the anchor devices 120-1 and 120-2) are participating in a positioning session with the target device 110. For example, the anchor devices 120-1 and 120-2 may send reference signals (e.g., SL PRS) to the target device 110 for SL positioning. In other words, the anchor devices 120-1 and 120-2 may provide SL positioning reference signal assistance to the target device 110.

[0055] The target device 110 determines 2010 whether reference signal transmission alignment is required between the anchor devices 120. In this way, the risk of the time reference at the target device changing during measurements of more / all anchor devices may be minimized.

[0056] In an example embodiment, the target device 110 may determine whether reference signal transmission alignment is required based on the possibility of synchronization reference change within the duration of the side link measurement of the reference signal from the anchor device (i.e., the reference time change possibility). For example, the target device 110 may determine the possibility of changing the synchronization reference device from device 140-1 to device 140-2. In this case, if the possibility is higher than a threshold (i.e., the synchronization reference device is likely to change from device 140-1 to device 140-2), the target device 110 may determine that reference signal transmission alignment is required.

[0057] In some example embodiments, the target device 110 may determine whether a subsequent synchronization search opportunity is within the duration of the sidelink measurement for the reference signal from the anchor device. The term "synchronization search opportunity" as used herein may refer to a time domain resource used to search for a synchronization reference device. If the subsequent synchronization search opportunity is within the duration of the sidelink measurement, the target device 110 may determine that reference signal alignment between the anchor device 120 is required. For example, if Figure 3A As shown, the target device 110 may be configured with synchronization search opportunities 310-1 and 310-2. The target device 110 may have searched for a synchronization device in the synchronization search opportunity 310-1. Figure 3A As shown, the subsequent synchronization search opportunity 310-2 may be within the duration 320 for performing the sidelink measurement by the target device 110. In this case, the target device 110 may determine that reference signal alignment between the anchor devices 120 is required.

[0058] In some other example embodiments, the target device 110 may determine whether the subsequent synchronization search opportunity is within a configured duration (e.g., within a certain millisecond). If the subsequent synchronization search opportunity is within the configured duration, the target device 110 may determine that reference signal alignment between the anchor device 120 is required. For example, the target device 110 may determine whether the subsequent synchronization search opportunity is within the duration 330 starting from the time instance 340. Figure 3B As shown, the subsequent synchronization search opportunity 310 - 2 may be within the duration 330 . In this case, the target device 110 may determine that reference signal alignment between the anchor device 120 is required.

[0059] In some example embodiments, the target device 110 may determine whether the reference signal received power for the current synchronization reference device is lower than a first reference signal received power threshold. If the reference signal received power is lower than the first reference signal received power threshold, the target device 110 may determine that reference signal alignment between the anchor devices 120 is required. For example, the target device 110 may measure the reference signal received power for the device 140-1 as the current synchronization reference device. In this case, if the measured reference signal received power is lower than the first reference signal received power threshold, the target device 110 may determine that reference signal alignment between the anchor devices 120 is required. Alternatively or additionally, the target device 110 may determine whether the synchronization priority of the current synchronization reference device is lower than the first priority threshold. If the synchronization priority is lower than the first priority threshold, the target device 110 may determine that reference signal alignment between the anchor devices 120 is required. For example, the target device 110 may determine the synchronization priority of the device 140-1. In this case, if the synchronization priority of the device 140-1 is lower than the first priority threshold, the target device 110 may determine that reference signal alignment between the anchor devices 120 is required. Table 1 below shows examples of different priorities of sources (where P0 to P6 correspond to the highest to the lowest priority, respectively), depending on whether it is GNSS-based synchronization (GNSS has the highest priority) or gNB / eNB-based synchronization (gNB / eNB has the highest priority). Note that Table 1 is only an example and not a limitation. Table 1

[0060] For example, if the synchronization priority of device 140 - 1 is “P6” and the first priority threshold is “P5”, target device 110 may determine that reference signal alignment between anchor devices 120 is required.

[0061] In some other example embodiments, the target device 110 may determine whether the reference signal received power for the candidate synchronization reference device is higher than a second reference signal received power threshold. For example, the second reference signal received power threshold may be the same as the first reference signal received power threshold. Alternatively, the second reference signal received power threshold may be different from the first reference signal received power threshold. If the reference signal received power is higher than the second reference signal received power threshold, the target device 110 may determine that reference signal alignment between the anchor devices 120 is required. For example, the target device 110 may measure the reference signal received power for the device 140-2 as the candidate synchronization reference device. In this case, if the measured reference signal received power is higher than the second reference signal received power threshold, the target device 110 may determine that reference signal alignment between the anchor devices 120 is required. Alternatively or additionally, the target device 110 may determine whether the synchronization priority of the candidate synchronization reference device is higher than the second priority threshold. If the synchronization priority is higher than the second priority threshold, the target device 110 may determine that reference signal alignment between the anchor devices 120 is required. For example, the target device 110 may determine the synchronization priority of the device 140-2. In this case, if the synchronization priority of device 140-2 is higher than the second priority threshold, target device 110 may determine that reference signal alignment between anchor devices 120 is required. For example, if the synchronization priority of device 140-2 is "P4" and the second priority threshold is "P5", target device 110 may determine that reference signal alignment between anchor devices 120 is required.

[0062] In an example embodiment, the target device 110 may determine whether reference signal alignment between the anchor devices 120 is required based on the clock drift performance of the target device 110. The term "clock drift performance" may refer to how the performance of the internal clock is. For example, if the clock drift performance is below a performance threshold (i.e., the clock drift performance is poor), the target device 110 may determine that reference signal alignment between the anchor devices 120 is required.

[0063] In another example embodiment, the target device 110 may determine an expected difference between a first time reference before the time reference change and a second time reference after the time reference change. If the expected difference is above a difference threshold, the target device 110 may determine that reference signal alignment between the anchor devices 120 is required. For example, when the synchronization device is device 140-1, the target device 110 may determine a first time reference; and when the synchronization device is device 140-2, the target device 110 may determine a second time reference. The target device 110 may determine whether the difference between the first time reference and the second time reference is above a difference threshold.

[0064] In an example embodiment, in the presence of a device 130 as a control entity (e.g., LMF or server UE), the target device 110 may send a reference signal transmission alignment trigger or indicate its SyncRef change possibility and clock drift characteristics to the device 130. The device 130 may then take action to achieve reference signal transmission alignment between the anchor devices. For example, if a reference signal transmission alignment device is required, the target device 110 may send (2020) information indicating that a reference signal transmission alignment device is required to the device 130. In this case, the device 130 may send a request for reference signal transmission alignment to one or more anchor devices 120 for triggering reference signal transmission alignment.

[0065] Alternatively, the target device 110 may send a reference signal transmission alignment request to one or more anchor devices 120 to trigger the reference signal transmission alignment. Figure 2 As shown, target device 110 may send (2030) a request for reference signal transmission alignment to anchor device 120-1, and send (2030') a request for reference signal transmission alignment to anchor device 120-2. In other words, anchor device 120 may receive a request for reference signal transmission alignment from target device 110 or device 130. Note that Figure 2 The order of sending (2030) and sending (2030') shown in FIG. 1 is only an example and not a limitation.

[0066] In an example embodiment, the request for reference signal transmission alignment may be sent via a sidelink positioning protocol message.Alternatively, the sidelink control information may include a request for reference signal transmission alignment.

[0067] The anchor device 120 may determine the transmission time window based on the request for reference signal transmission alignment. Figure 4A and Figure 4A As shown, anchor device 120 may determine transmission time window 430 based on the request. For example, anchor device 120-1 may determine (2040) a transmission time window based on the request for reference signal transmission alignment. Anchor device 120-2 may determine (2040') a transmission window based on the request for reference signal transmission alignment. Note that Figure 2 The order of determining (2040) and determining (2040') shown in FIG. 2 is merely an example and not a limitation.

[0068] In some example embodiments, the request for reference signal transmission alignment may include an indication for triggering reference signal transmission alignment. Alternatively or additionally, the request for reference signal transmission alignment may include a time reference point for a transmission time window. The request for reference signal transmission alignment may also include time window information indicating a start point and an end point of the transmission time window starting from the time reference point. Anchor device 120 may determine an actual start point and an actual end point of the transmission time window based on the time window information and the time reference point. For example, Figure 4A As shown, the anchor device 120 can determine the actual start point (410-1) and the actual end point (420-1) of the transmission time window (430) based on the time window information and the time reference point (410-1). The anchor device 120 can determine the actual start point (410-2) and the actual end point (420-2) of the transmission time window (430) based on the time window information and the time reference point (410-2).

[0069] In an example embodiment, the time reference point in the request may include a time point of receipt of the request for reference signal transmission alignment. In this case, the anchor device 120 may determine the actual start point of the transmission time window as the time point of receipt of the request for reference signal transmission alignment. Figure 4A As shown, if the anchor device 120 receives the request at time point 410-1, the reception time point 410-1 can be determined as the actual starting point of the transmission time window. In some other example embodiments, the side link positioning protocol message can be used to indicate the need (i.e., request) for reference signal transmission alignment, and the side link control information can be used as a time reference point for the transmission time window. In this case, if the side link control information is received at time point 410-1, the reception time point 410-1 can be determined as the actual starting point of the transmission time window.

[0070] Alternatively, the time reference point includes a reception time point of a sidelink signal from one or more anchor devices 120. In this case, the request for reference signal transmission alignment may also include source identity information of the anchor devices 120. For example, the request may include the identities of the anchor devices 120-1, 120-2, and 120-3. Alternatively or additionally, the request for reference signal transmission alignment may include destination identity information used by the anchor device 120. For example, the request for reference signal transmission alignment may include the identity of the target device 110.

[0071] In an example embodiment, the anchor device 120 may broadcast a sidelink signal including its identity and / or the identity of the target device 110. For example, the anchor device 120-1 may broadcast a sidelink signal including one or more of the following to other anchor devices (e.g., the anchor device 120-2 and / or the anchor device 120-3): the identity of the anchor device 120-1 or the identity of the target device 110. In some embodiments, the sidelink signal may be a SL PRS. Alternatively, the sidelink signal may be sidelink control information.

[0072] Alternatively, the anchor device 120 may use at least one of the source identity information or the destination identity information to monitor a side link signal (e.g., SL PRS or side link control information) from one or more anchor devices. For example, the anchor device 120-2 may monitor a side link signal from another anchor device (e.g., the anchor device 120-1). The side link signal may include one or more of the following: the identity of the anchor device 120-1 or the identity of the target device 110. In this case, the anchor device 120-2 may determine the actual starting point of the transmission time window as the reception time point of the signal from the other anchor device. For example, as Figure 4B As shown, if the anchor device 120-2 receives the side link signal from the anchor device 120-1 at the time point 410-2, the reception time point 410-2 may be determined as the actual start point of the transmission time window.

[0073] The anchor device 120 transmits a reference signal (e.g., SL PRS) to at least the target device 110 according to a transmission time window (e.g., transmission time window 430). In other words, the target device 110 may receive the reference signal from one or more anchor devices (e.g., anchor device 120-1 and anchor device 120-2) within the transmission time window. For example, the anchor device 120 may broadcast the reference signal to the target device 110 and other anchor devices. For example, Figure 2 As shown, anchor device 120-1 may send (2050) a reference signal to at least target device 110 within transmission time window 430. Anchor device 120-2 may send (2050') a reference signal to at least target device 110 within transmission time window 430. Note that Figure 2 The order of sending (2050) and sending (2050') shown in FIG. 1 is only an example and not a limitation.

[0074] The anchor device 120 may obtain a configuration of a resource selection window based on the transmission time window. In an example embodiment, the anchor device 120 may use the time constraint (i.e., the transmission time window) at its physical layer and medium access control (MAC) layer for sidelink resource selection within the transmission time window. In this case, the physical layer sidelink resource selection window may be configured based on the time window.

[0075] Target device 110 performs (2060) measurements using the one or more reference signals received from anchor device 120. For example, target device 110 may perform SL reference signal time difference (RSTD) measurements using the received one or more reference signals. As an example, target device 110 may measure the arrival time difference of reference signals from anchor devices 120-1 and 120-2.

[0076] In some example embodiments, target device 110 may perform (2080) a position estimation of target device 110 based on the measurements (i.e., the measurement results). Alternatively, target device 110 may send (2070) a report indicating the measurements (i.e., the measurement results) of the received reference signal to device 130. In this case, device 130 may perform (2080') a position estimation of target device 110 based on the measurements indicated in the report.

[0077] In a further embodiment, in an in-coverage scenario, the device 130 may indicate transmission time windows / relative timing requirements to different gNBs (e.g., serving different anchor terminal devices) in order to achieve timely and aligned resource allocation. For example, the device 130 may send further information indicating the requirement for transmission time windows aligned for reference signal transmissions to another set of network devices of the anchor device 120. Alternatively, the device 130 may indicate the required timing to the anchor device 120 and the SL resource allocation to their own serving gNB. For example, the device 130 may send further information to the anchor device 120 indicating the requirement for transmission time windows aligned for reference signal transmissions.

[0078] According to reference Figure 2 In the described embodiments, the target device determines the need for reference signal transmission alignment between anchor devices based at least on its synchronization reference change probability and / or clock drift characteristics. The target device triggers reference signal transmission alignment between anchor devices by sending an "alignment trigger" to its anchor device. The anchor device aligns its reference signal transmission according to the received trigger. This can mitigate the impact of changes in the synchronization timing reference at the target device in the measurement. Therefore, the solution can achieve high-precision measurements, thereby achieving high-precision sidelink positioning. Example Method

[0079] Figure 5 A flowchart of an example method 500 implemented at an anchor device according to some example embodiments of the present disclosure is shown. For the purpose of discussion, Figure 1 Method 500 is described from the perspective of anchoring device 120 in FIG.

[0080] At block 510, the anchor device 120 obtains a request for reference signal transmission alignment for triggering reference signal transmission alignment with the set of devices 120. The anchor device 120 and the set of devices 120 are participating in a positioning session with the target device 110.

[0081] At block 520, the anchor device 120 determines a transmission time window for reference signal transmission alignment based on the request for reference signal transmission alignment.

[0082] At block 530, anchor device 120 transmits a reference signal according to the transmission time window to at least target device 110. In some example embodiments, the reference signal is a sidelink positioning reference signal.

[0083] In some example embodiments, the request for reference signal transmission alignment is received in at least one of: a sidelink positioning protocol message, or a sidelink control message. In some example embodiments, the request for reference signal transmission alignment includes at least one of: an indication for triggering reference signal transmission alignment, a time reference point for a transmission time window, or time window information indicating a start and end point of the transmission time window from the time reference point.

[0084] In some example embodiments, method 500 further comprises: determining an actual start point and an actual end point of the transmission time window based on the time window information and the time reference point. In some example embodiments, method 500 further comprises: determining the actual start point of the transmission time window as a reception time point of a request for reference signal transmission alignment.

[0085] In some example embodiments, the time reference point includes a reception time point of a side link signal from one or more devices in the device set, and the request for reference signal transmission alignment also includes at least one of the following: source identity information of the device set, or destination identity information used by the device set.

[0086] In some example embodiments, method 500 further includes: monitoring a side link signal from one or more devices using at least one of the source identity information or the destination identity information; and determining, based on a determination of receiving the side link signal, an actual starting point of the transmission time window as a point in time at which the signal from the one or more devices is received.

[0087] In some example embodiments, the method 500 further comprises: broadcasting a second side link signal to the set of devices, the second side link signal comprising one of: an identity of the apparatus or an identity of the target device. In some example embodiments, the method 500 further comprises: obtaining a configuration of a resource selection window according to the transmission time window.

[0088] In some example embodiments, the method 500 further includes: receiving a request for reference signal transmission alignment from a target device; or receiving a request for reference signal transmission alignment from another device that is a server terminal device or a network node.

[0089] Figure 6 A flowchart of an example method 600 implemented at a target device according to some example embodiments of the present disclosure is shown. For the purpose of discussion, Figure 1 The method 600 is described from the perspective of the target device 110 in FIG.

[0090] At block 610 , the target device 110 determines whether reference signal transmission alignment is required between a set of devices that are participating in a positioning session with an apparatus.

[0091] At block 620, the target device 110 receives a reference signal from at least one device in the set of devices according to a transmission time window determined by the at least one device based on a request for reference signal transmission alignment.

[0092] At block 630, the target device 110 performs measurements using the received reference signal. In some example embodiments, the reference signal is a sidelink positioning reference signal.

[0093] In some example embodiments, the method 600 further comprises determining whether reference signal alignment between the set of devices is required based on a reference time change likelihood within a duration of a sidelink measurement of reference signals from the set of devices.

[0094] In some example embodiments, method 600 further includes determining that reference signal alignment between a set of devices is required based on a determination that at least one of the following is satisfied: a next synchronization search opportunity at the device is within the duration of a sidelink measurement for a reference signal from a set of devices, a next synchronization search opportunity at the device is within a configured duration, a reference signal reception power for a current synchronization reference device of the device is lower than a first reference signal reception power threshold, a synchronization priority of the current synchronization reference device is lower than a first priority threshold, a reference signal reception power for a candidate synchronization reference device of the device is higher than a second reference signal reception power threshold, a synchronization priority of the candidate synchronization reference device is higher than a second priority threshold, a clock drift performance at the device is lower than a performance threshold, or a difference between a first time reference before a change in the time reference and a second time reference after the change in the time reference is higher than a difference threshold.

[0095] In some example embodiments, method 600 further includes: based on the determination that reference signal transmission alignment between the set of devices is required, sending a request for reference signal transmission alignment to the set of devices for triggering the reference signal transmission alignment. In some example embodiments, the request for reference signal transmission alignment is sent in at least one of: a sidelink positioning protocol message, or a sidelink control message.

[0096] In some example embodiments, the method 600 further comprises: based on the determination that reference signal transmission alignment between the set of devices is required, notifying another device that the reference signal transmission alignment between the set of devices is required.

[0097] In some example embodiments, the request for reference signal transmission alignment includes at least one of: an indication for triggering reference signal transmission alignment, a time reference point for a transmission time window, or time window information indicating a start and end point of the transmission time window starting from the time reference point.

[0098] In some example embodiments, the time reference point comprises a reception time point of a request for reference signal transmission alignment, or wherein the time reference point comprises a reception time point of a sidelink signal from one or more devices in the set of devices.

[0099] In some example embodiments, the request for reference signal transmission alignment further includes at least one of: source identity information of the set of devices, or destination identity information used by the set of devices.

[0100] In some example embodiments, the method 600 further comprises: performing a position estimation of the apparatus based on the measurement of the received reference signal. In some example embodiments, the method 600 further comprises: sending a report indicating the measurement of the received reference signal to another device.

[0101] Figure 7 A flowchart of an example method 700 implemented at a device according to some example embodiments of the present disclosure is shown. For the purpose of discussion, Figure 1 Method 700 is described from the perspective of device 130 in FIG.

[0102] At block 710, the device 130 receives information from a device indicating that reference signal transmission alignment between a set of devices is required. The set of devices is participating in a positioning session with the device.

[0103] At block 720, device 130 sends a request for reference signal transmission alignment to the set of devices for triggering reference signal transmission alignment. In some example embodiments, method 700 further includes: receiving a report from the device indicating measurements performed by the device based on a reference signal received from at least one device in the set of devices; and performing a position estimation of the device based on the measurements.

[0104] In some example embodiments, the method 700 further comprises: sending further information indicating a requirement for a transmission time window aligned for reference signal transmission to another set of network devices in the set of devices. In some example embodiments, the method 700 further comprises: sending further information indicating a requirement for a transmission time window aligned for reference signal transmission to the set of devices.

[0105] In some example embodiments, the apparatus comprises a server terminal device or a location management function node, the device comprises a target terminal device, and the set of devices comprises a set of anchor terminal devices. Example devices, equipment, and media

[0106] In some example embodiments, a first device (eg, Figure 1 The target device 110 in the method 500 may include a component for performing the corresponding operation of the method 500. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit or a software module. The first device may be implemented as or included in Figure 1 In the target device 110.

[0107] In some example embodiments, a first device includes components for receiving a request for reference signal transmission alignment for triggering reference signal transmission alignment with a set of devices, wherein the device and the set of devices are participating in a positioning session with a target device; components for determining a transmission time window for reference signal transmission alignment based on the request for reference signal transmission alignment; and components for sending a reference signal to at least the target device according to the transmission time window.

[0108] In some example embodiments, the request for reference signal transmission alignment is received in at least one of: a sidelink positioning protocol message, or a sidelink control message.

[0109] In some example embodiments, the request for reference signal transmission alignment includes at least one of: an indication for triggering reference signal transmission alignment, a time reference point for a transmission time window, or time window information indicating a start and end point of the transmission time window starting from the time reference point.

[0110] In some example embodiments, the first apparatus further comprises: means for determining an actual start point and an actual end point of the transmission time window based on the time window information and the time reference point.

[0111] In some example embodiments, the time reference point comprises a reception time point of a request for reference signal transmission alignment, and wherein the first device further comprises: a component for determining the actual starting point of the transmission time window as the reception time point of the request for reference signal transmission alignment.

[0112] In some example embodiments, the time reference point includes a reception time point of a side link signal from one or more devices in the device set, and wherein the request for reference signal transmission alignment also includes at least one of: source identity information of the device set, or destination identity information used by the device set.

[0113] In some example embodiments, the first apparatus further comprises: a component for monitoring a side link signal from one or more devices using at least one of the source identity information or the destination identity information; and a component for determining, based on a determination of receiving the side link signal, an actual starting point of the transmission time window as a point in time of reception of the signal from the one or more devices.

[0114] In some example embodiments, the first apparatus further comprises: means for broadcasting a further side link signal to the set of devices, the further side link signal comprising one of: an identity of the apparatus or an identity of a target device.

[0115] In some example embodiments, the first apparatus further comprises means for obtaining a configuration of a resource selection window according to the transmission time window.

[0116] In some example embodiments, the first apparatus further comprises: means for receiving a request for reference signal transmission alignment from a target device; or means for receiving a request for reference signal transmission alignment from another device being a server terminal device or a network node.

[0117] In some example embodiments, the reference signal is a sidelink positioning reference signal.

[0118] In some example embodiments, the apparatus comprises another anchor terminal device, the target device comprises a target terminal device, and the set of devices comprises a set of anchor terminal devices.

[0119] In some example embodiments, the first apparatus further comprises means for performing the method 500 or other operations in some example embodiments of the target device 110. In some example embodiments, the means comprises at least one processor; at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to perform.

[0120] In some example embodiments, a second device (eg, Figure 1The anchor device 120 in the second device may include a component for performing the corresponding operation of the method 600. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit or a software module. The second device may be implemented as or included in Figure 1 In the anchoring device 120.

[0121] In some example embodiments, the second device includes: a device for determining whether reference signal transmission alignment between a set of devices is required, wherein the set of devices is participating in a positioning session with the device; a component for receiving a reference signal from at least one device in the set of devices according to a transmission time window, the transmission time window being determined by the at least one device based on a request for reference signal transmission alignment; and a component for performing measurements using the received reference signal.

[0122] In some example embodiments, the second apparatus further comprises means for determining whether reference signal alignment between the set of devices is required based on a reference time change likelihood within a duration of a sidelink measurement of reference signals from the set of devices.

[0123] In some example embodiments, the second device further includes: a component for determining that reference signal alignment between the device set is required based on a determination that at least one of the following is satisfied: a next synchronization search opportunity at the device is within the duration of a sidelink measurement for a reference signal from the device set, a next synchronization search opportunity at the device is within a configured duration, a reference signal reception power for a current synchronization reference device of the device is lower than a first reference signal reception power threshold, a synchronization priority of the current synchronization reference device is lower than a first priority threshold, a reference signal reception power for a candidate synchronization reference device of the device is higher than a second reference signal reception power threshold, a synchronization priority of the candidate synchronization reference device is higher than a second priority threshold, a clock drift performance at the device is lower than a performance threshold, or a difference between a first time reference before a change in the time reference and a second time reference after the change in the time reference is higher than a difference threshold.

[0124] In some example embodiments, the second apparatus further comprises means for sending a request for reference signal transmission alignment to the set of devices for triggering the reference signal transmission alignment based on the determination that reference signal transmission alignment between the set of devices is required.

[0125] In some example embodiments, the request for reference signal transmission alignment is sent in at least one of: a sidelink positioning protocol message, or a sidelink control message.

[0126] In some example embodiments, the second apparatus further comprises means for notifying another device that alignment of reference signal transmissions between the set of devices is required based on the determination that alignment of reference signal transmissions between the set of devices is required.

[0127] In some example embodiments, the request for reference signal transmission alignment includes at least one of: an indication for triggering reference signal transmission alignment, a time reference point for a transmission time window, or time window information indicating a start and end point of the transmission time window starting from the time reference point.

[0128] In some example embodiments, the time reference point comprises a reception time point of a request for reference signal transmission alignment, or wherein the time reference point comprises a reception time point of a sidelink signal from one or more devices in the set of devices.

[0129] In some example embodiments, the request for reference signal transmission alignment further includes at least one of: source identity information of the set of devices, or destination identity information used by the set of devices.

[0130] In some example embodiments, the second apparatus further comprises means for performing a positioning estimate of the apparatus based on measurements of the received reference signal.

[0131] In some example embodiments, the second apparatus further comprises means for sending a report indicating the measurement of the received reference signal to another device.

[0132] In some example embodiments, the reference signal is a sidelink positioning reference signal.

[0133] In some example embodiments, the apparatus comprises a target terminal device, and the set of devices comprises a set of anchor terminal devices.

[0134] In some example embodiments, the second apparatus further comprises means for performing the method 600 or other operations in some example embodiments of the anchor device 120. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to perform.

[0135] In some example embodiments, a third device (eg, Figure 1 The device 130 in the method 700 may include a component for performing the corresponding operation of the method 700. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit or a software module. The third device may be implemented as or included in Figure 1 in device 130.

[0136] In some example embodiments, the third apparatus includes: a component for receiving information from a device indicating that reference signal transmission alignment is required between a set of devices, wherein the set of devices is participating in a positioning session with the device; and a component for sending a request for reference signal transmission alignment to the set of devices for triggering the reference signal transmission alignment.

[0137] In some example embodiments, the third apparatus further comprises: means for receiving a report from the device indicating measurements performed by the device based on a reference signal received from at least one device in the set of devices; and means for performing a position estimation of the device based on the measurements.

[0138] In some example embodiments, the third device also includes: a component for sending further information indicating the requirement for a transmission time window for reference signal transmission alignment to another network device set in the device set; or a component for sending further information indicating the requirement for a transmission time window for reference signal transmission alignment to the device set.

[0139] In some example embodiments, the apparatus comprises a server terminal device or a location management function node, the device comprises a target terminal device, and the set of devices comprises a set of anchor terminal devices.

[0140] In some example embodiments, the third apparatus further comprises means for performing other operations in some example embodiments of method 700 or device 130. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the third apparatus to perform.

[0141] Figure 8 8 is a simplified block diagram of a device 800 suitable for implementing an example embodiment of the present disclosure. The device 800 may be provided to implement a communication device, such as Figure 1 The target device 110 or the anchor device 120 or the device 130 is shown. As shown, the device 800 includes one or more processors 810, one or more memories 820 coupled to the processor 810, and one or more communication modules 840 coupled to the processor 810.

[0142] The communication module 840 is used for two-way communication. The communication module 840 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interface can represent any interface required to communicate with other network elements. In some example embodiments, the communication module 840 may include at least one antenna.

[0143] Processor 810 may be of any type suitable for the local technology network, and may include one or more of: a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture, as non-limiting examples. Device 800 may have multiple processors, such as application specific integrated circuit chips that are time slaved to a clock of a synchronized main processor.

[0144] The memory 820 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 824, electrically programmable read-only memory (EPROM), flash memory, hard disk, compact disk (CD), digital video disk (DVD), optical disk, laser disk, and other magnetic storage and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 822 and other volatile memories that do not persist during power outages.

[0145] The computer program 830 includes computer executable instructions executed by the associated processor 810. The instructions of the program 830 may include instructions for performing the operations / actions of some example embodiments of the present disclosure. The program 830 may be stored in a memory, such as ROM 824. The processor 810 may perform any suitable actions and processes by loading the program 830 into the RAM 822.

[0146] The exemplary embodiments of the present disclosure may be implemented by a program 830 so that the device 800 may execute the Figures 2 to 7 Any process of the present disclosure discussed. The exemplary embodiments of the present disclosure may also be implemented in hardware or a combination of software and hardware.

[0147] In some example embodiments, the program 830 may be tangibly embodied in a computer-readable medium, which may be contained in the device 800 (e.g., in the memory 820) or in other storage devices accessible to the device 800. The device 800 may load the program 830 from the computer-readable medium to the RAM 822 for execution. In some example embodiments, the computer-readable medium may include any type of non-transitory storage medium, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. As used herein, the term "non-transitory" is a limitation on the medium itself (i.e., tangible, non-signal), not on data storage persistence (e.g., RAM vs. ROM).

[0148] Fig. 9 An example of a computer readable medium 900 is shown, which may be in the form of a CD, DVD or other optical storage disk. The computer readable medium 900 has a program 830 stored thereon.

[0149] In general, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that the boxes, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices, or some combination thereof as non-limiting examples.

[0150] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer-readable medium (e.g., a non-transitory computer-readable medium). The computer program product includes computer executable instructions, such as those included in a program module, which are executed in a device on a target physical or virtual processor to perform any of the methods described above. In general, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The functions of program modules can be combined or split between program modules as needed in different embodiments. The machine executable instructions of the program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in local and remote storage media.

[0151] The program code for executing the method of the present disclosure can be written in any combination of one or more programming languages. The program code can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device, so that the program code causes the functions / operations specified in the flow chart and / or block diagram to be executed when executed by the processor or controller. The program code can be executed entirely on the machine, partially on the machine, as an independent software package, partially on the machine and partially on a remote machine, or completely on a remote machine or server.

[0152] In the context of the present disclosure, computer program codes or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of carriers include signals, computer readable media, etc.

[0153] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. The computer readable medium may include, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared or semiconductor system, device or apparatus, or any suitable combination of the foregoing. More specific examples of computer readable storage media would include an electrical connection with one or more wires, a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0154] In addition, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in a continuous order, or that all of the operations shown be performed, in order to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be interpreted as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to a particular embodiment. Unless expressly stated, certain functions described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless expressly stated, various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable sub-combination.

[0155] Although the disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

[0156] In some aspects, a device for communication is provided, comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the device to: receive a request for reference signal transmission alignment for triggering the reference signal transmission alignment with a set of devices, wherein the device and the set of devices are participating in a positioning session with a target device; determine a transmission time window for the reference signal transmission alignment based on the request for reference signal transmission alignment; and send a reference signal to at least the target device according to the transmission time window.

[0157] In some example embodiments, the request for reference signal transmission alignment is received in at least one of: a sidelink positioning protocol message, or a sidelink control information.

[0158] In some example embodiments, the request for reference signal transmission alignment includes at least one of: an indication for triggering the reference signal transmission alignment, a time reference point for the transmission time window, or time window information indicating the start and end points of the transmission time window starting from the time reference point.

[0159] In some example embodiments, the apparatus is caused to determine an actual start point and an actual end point of the transmission time window based on the time window information and the time reference point.

[0160] In some example embodiments, the time reference point includes a reception time point of the request for reference signal transmission alignment, and wherein the apparatus is caused to: determine the actual starting point of the transmission time window as the reception time point of the request for reference signal transmission alignment.

[0161] In some example embodiments, the time reference point includes a reception time point of a side link signal from one or more devices in the device set, and wherein the request for reference signal transmission alignment also includes at least one of: source identity information of the device set, or destination identity information used by the device set.

[0162] In some example embodiments, the apparatus is configured to: monitor the side link signal from the one or more devices using at least one of the source identity information or the destination identity information; and determine the actual starting point of the transmission time window as the reception time point of the signal from the one or more devices based on a determination of receiving the side link signal.

[0163] In some example embodiments, the apparatus is caused to: broadcast a further side link signal to the set of devices, the further side link signal comprising one of: an identity of the apparatus or an identity of the target device.

[0164] In some example embodiments, the apparatus is caused to obtain a configuration of a resource selection window based on the transmission time window.

[0165] In some example embodiments, the apparatus is caused to: receive the request for reference signal transmission alignment from the target device; or receive the request for reference signal transmission alignment from another device that is a server terminal device or a network node.

[0166] In some example embodiments, the reference signal is a sidelink positioning reference signal.

[0167] In some example embodiments, the apparatus comprises an anchor terminal device, the target device comprises a target terminal device, and the set of devices comprises a set of anchor terminal devices.

[0168] In some aspects, a device for communication is provided, comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the device to: determine whether reference signal transmission alignment between a set of devices is required, wherein the set of devices is participating in a positioning session with the device; receive a reference signal from at least one device in the set of devices according to a transmission time window determined by the at least one device based on the request for reference signal transmission alignment; and perform measurements using the received reference signal.

[0169] In some example embodiments, the apparatus is caused to determine whether alignment of the reference signals between the set of devices is required based on a likelihood of a reference time change within a duration of a sidelink measurement of reference signals from the set of devices.

[0170] In some example embodiments, the apparatus is caused to: determine that the reference signal alignment between the set of devices is required based on a determination that at least one of the following is satisfied: a next synchronization search opportunity at the apparatus is within the duration of a sidelink measurement of a reference signal from the set of devices, the next synchronization search opportunity at the apparatus is within a configured duration, a reference signal reception power for a current synchronization reference device of the apparatus is lower than a first reference signal reception power threshold, a synchronization priority of the current synchronization reference device is lower than a first priority threshold, a reference signal reception power for a candidate synchronization reference device of the apparatus is higher than a second reference signal reception power threshold, a synchronization priority of the candidate synchronization reference device is higher than a second priority threshold, a clock drift performance at the apparatus is lower than a performance threshold, or a difference between a first time reference before a change in time reference and a second time reference after the change in time reference is higher than a difference threshold.

[0171] In some example embodiments, the apparatus is caused to: based on a determination that the reference signal transmission alignment between the set of devices is required, send the request for reference signal transmission alignment to the set of devices for triggering the reference signal transmission alignment.

[0172] In some example embodiments, the request for reference signal transmission alignment is sent in at least one of: a sidelink positioning protocol message, or a sidelink control message.

[0173] In some example embodiments, the apparatus is caused to, based on a determination that the reference signal transmission alignment between the set of devices is required, notify another device that the reference signal transmission alignment between the set of devices is required.

[0174] In some example embodiments, the request for reference signal transmission alignment includes at least one of: an indication for triggering the reference signal transmission alignment, a time reference point for the transmission time window, or time window information indicating the start and end points of the transmission time window starting from the time reference point.

[0175] In some example embodiments, the time reference point comprises a reception time point of the request for reference signal transmission alignment, or wherein the time reference point comprises a reception time point of a side link signal from one or more devices in the set of devices.

[0176] In some example embodiments, the request for reference signal transmission alignment further includes at least one of: source identity information of the set of devices, or destination identity information used by the set of devices.

[0177] In some example embodiments, the apparatus is further caused to perform a positioning estimate of the apparatus based on the measurements of the received reference signals.

[0178] In some example embodiments, the apparatus is further caused to send a report indicating the measurement of the received reference signal to the other device.

[0179] In some example embodiments, the reference signal is a sidelink positioning reference signal.

[0180] In some example embodiments, the apparatus comprises a target terminal device, and the set of devices comprises a set of anchor terminal devices.

[0181] In some aspects, a device for communication is provided, comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the device to: receive information from a device indicating that reference signal transmission alignment is required between a set of devices, wherein the set of devices is participating in a positioning session with the devices; and send a request for the reference signal transmission alignment to the set of devices to trigger the reference signal transmission alignment.

[0182] In some example embodiments, the apparatus is further caused to: receive a report from the device indicating measurements performed by the device based on a reference signal received from at least one device in the set of devices; and perform a position estimation of the device based on the measurements.

[0183] In some example embodiments, the apparatus is further caused to: send further information indicating a requirement for a transmission time window for alignment of the reference signal transmission to another set of network devices in the set of devices; or send further information indicating a requirement for the transmission time window for alignment of the reference signal transmission to the set of network devices.

[0184] In some example embodiments, the apparatus comprises a server terminal device or a location management function node, the device comprises a target terminal device, and the set of devices comprises a set of anchor terminal devices.

[0185] In some aspects, a method for communication is provided, comprising: receiving, at a device, a request for reference signal transmission alignment for triggering the reference signal transmission alignment with a set of devices, wherein the device and the set of devices are participating in a positioning session with a target device; determining a transmission time window for the reference signal transmission alignment based on the request for reference signal transmission alignment; and sending a reference signal to at least the target device according to the transmission time window.

[0186] In some example embodiments, the request for reference signal transmission alignment is received in at least one of: a sidelink positioning protocol message, or a sidelink control information.

[0187] In some example embodiments, the request for reference signal transmission alignment includes at least one of: an indication for triggering the reference signal transmission alignment, a time reference point for the transmission time window, or time window information indicating the start and end points of the transmission time window starting from the time reference point.

[0188] In some example embodiments, determining the transmission time window includes determining an actual start point and an actual end point of the transmission time window based on the time window information and the time reference point.

[0189] In some example embodiments, the time reference point includes a reception time point of the request for reference signal transmission alignment, and wherein determining the transmission time window includes determining an actual starting point of the transmission time window as the reception time point of the request for reference signal transmission alignment.

[0190] In some example embodiments, the time reference point includes a reception time point of a side link signal from one or more devices in the device set, and wherein the request for reference signal transmission alignment also includes at least one of: source identity information of the device set, or destination identity information used by the device set.

[0191] In some example embodiments, the method further includes: monitoring the side link signal from the one or more devices using at least one of the source identity information or the destination identity information; and determining the actual starting point of the transmission time window as the reception time point of the signal from the one or more devices based on a determination of receiving the side link signal.

[0192] In some example embodiments, the method further comprises: broadcasting another side link signal to the set of devices, the other side link signal comprising one of: an identity of the apparatus or an identity of the target device.

[0193] In some example embodiments, the method further comprises: obtaining a configuration of a resource selection window according to the transmission time window.

[0194] In some example embodiments, the method further comprises: receiving the request for reference signal transmission alignment from the target device; or receiving the request for reference signal transmission alignment from another device that is a server terminal device or a network node.

[0195] In some example embodiments, the reference signal is a sidelink positioning reference signal.

[0196] In some example embodiments, the apparatus comprises an anchor terminal device, the target device comprises a target terminal device, and the set of devices comprises a set of anchor terminal devices.

[0197] In some aspects, a method for communication is provided, comprising: determining at a device whether reference signal transmission alignment is required between a set of devices, wherein the set of devices is participating in a positioning session with the device; receiving a reference signal from at least one device in the set of devices according to a transmission time window determined by the at least one device based on the request for reference signal transmission alignment; and performing measurements using the received reference signal.

[0198] In some example embodiments, determining whether alignment of the reference signals between the set of devices is required includes determining whether alignment of the reference signals between the set of devices is required based on a likelihood of a reference time change within a duration of a sidelink measurement of a reference signal from the set of devices.

[0199] In some example embodiments, determining whether the reference signal alignment between the set of devices is required includes: determining that the reference signal alignment between the set of devices is required based on a determination that at least one of the following is satisfied: a next synchronization search opportunity at the device is within the duration of a sidelink measurement of a reference signal from the set of devices, the next synchronization search opportunity at the device is within a configured duration, a reference signal reception power for a current synchronization reference device of the device is lower than a first reference signal reception power threshold, a synchronization priority of the current synchronization reference device is lower than a first priority threshold, a reference signal reception power for a candidate synchronization reference device of the device is higher than a second reference signal reception power threshold, a synchronization priority of the candidate synchronization reference device is higher than a second priority threshold, a clock drift performance at the device is lower than a performance threshold, or a difference between a first time reference before a change in a time reference and a second time reference after the change in the time reference is higher than a difference threshold.

[0200] In some example embodiments, the method further comprises: based on a determination that the reference signal transmission alignment between the set of devices is required, sending the request for reference signal transmission alignment to the set of devices to trigger the reference signal transmission alignment.

[0201] In some example embodiments, the request for reference signal transmission alignment is sent in at least one of: a sidelink positioning protocol message, or a sidelink control message.

[0202] In some example embodiments, the method further comprises: based on the determination that the reference signal transmission alignment between the set of devices is required, notifying another device that the reference signal transmission alignment between the set of devices is required.

[0203] In some example embodiments, the request for reference signal transmission alignment includes at least one of: an indication for triggering the reference signal transmission alignment, a time reference point for the transmission time window, or time window information indicating the start and end points of the transmission time window starting from the time reference point.

[0204] In some example embodiments, the time reference point comprises a reception time point of the request for reference signal transmission alignment, or wherein the time reference point comprises a reception time point of a side link signal from one or more devices in the set of devices.

[0205] In some example embodiments, the request for reference signal transmission alignment further includes at least one of: source identity information of the set of devices, or destination identity information used by the set of devices.

[0206] In some example embodiments, the method further comprises performing a positioning estimate for the apparatus based on the measurements of the received reference signals.

[0207] In some example embodiments, the method further comprises sending a report to the other device indicating the measurement of the received reference signal.

[0208] In some example embodiments, the reference signal is a sidelink positioning reference signal.

[0209] In some example embodiments, the apparatus comprises a target terminal device, and the set of devices comprises a set of anchor terminal devices.

[0210] In some aspects, a method for communication is provided, comprising: receiving, at an apparatus and from a device, information indicating that reference signal transmission alignment is required between a set of devices, wherein the set of devices is participating in a positioning session with the devices; and sending a request for the reference signal transmission alignment to the set of devices for triggering the reference signal transmission alignment.

[0211] In some example embodiments, the method further comprises: receiving a report from the device indicating measurements performed by the device based on a reference signal received from at least one device in the set of devices; and performing a position estimation of the device based on the measurements.

[0212] In some example embodiments, the method further includes: sending further information indicating a requirement for a transmission time window for alignment of the reference signal transmission to another set of network devices in the set of devices; or sending further information indicating a requirement for the transmission time window for alignment of the reference signal transmission to the set of network devices.

[0213] In some example embodiments, the apparatus comprises a server terminal device or a location management function node, the device comprises a target terminal device, and the set of devices comprises a set of anchor terminal devices.

[0214] In some aspects, a computer-readable medium is provided, comprising instructions stored thereon, for causing an apparatus to perform at least a method comprising: receiving a request for reference signal transmission alignment for triggering the reference signal transmission alignment with a set of devices, wherein the apparatus and the set of devices are participating in a positioning session with a target device; determining a transmission time window for the reference signal transmission alignment based on the request for reference signal transmission alignment; and transmitting a reference signal to at least the target device according to the transmission time window.

[0215] In some aspects, a computer-readable medium is provided, comprising instructions stored thereon for causing an apparatus to perform at least a method comprising: determining whether reference signal transmission alignment between a set of devices is required, wherein the set of devices is participating in a positioning session with the apparatus; receiving a reference signal from at least one device in the set of devices according to a transmission time window determined by the at least one device based on the request for reference signal transmission alignment; and performing measurements using the received reference signal.

[0216] In some aspects, a computer-readable medium is provided, comprising instructions stored thereon for causing an apparatus to perform at least a method comprising: receiving information from a device indicating a need for reference signal transmission alignment between a set of devices, wherein the set of devices is participating in a positioning session with the devices; and sending a request for the reference signal transmission alignment to the set of devices for triggering the reference signal transmission alignment.

Claims

1. A device for communication, comprising: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to: receiving a request for reference signal transmission alignment for triggering said reference signal transmission alignment with a set of devices, wherein said apparatus and said set of devices are participating in a positioning session with a target device; Based on the request for reference signal transmission alignment, determining a transmission time window for the reference signal transmission alignment; as well as At least a reference signal is sent to the target device according to the transmission time window.

2. The apparatus of claim 1 , wherein the request for reference signal transmission alignment is received in at least one of: Sidelink Positioning Protocol message, or Sidelink control information.

3. The apparatus according to claim 1, wherein the request for reference signal transmission alignment comprises at least one of the following: an indication for triggering the alignment of the reference signal transmission, a time reference point for said transmission time window, or Time window information indicating a start point and an end point of the transmission time window from the time reference point.

4. The apparatus according to claim 3, wherein the apparatus is configured to: An actual start point and an actual end point of the transmission time window are determined based on the time window information and the time reference point.

5. The apparatus according to claim 3 or 4, wherein the time reference point comprises a reception time point of the request for reference signal transmission alignment, and wherein the apparatus is caused to: The actual starting point of the transmission time window is determined as the reception time point of the request for reference signal transmission alignment.

6. The apparatus according to claim 3 or 4, wherein the time reference point comprises a reception time point of a side link signal from one or more devices in the set of devices, and The request for reference signal transmission alignment further includes at least one of the following: the source identity information of the set of devices, or The destination identity information used by the set of devices.

7. The apparatus according to claim 6, wherein the apparatus is configured to: monitoring the sidelink signal from the one or more devices using at least one of the source identity information or the destination identity information; and Based on a determination that the sidelink signal is received, the actual starting point of the transmission time window is determined to be the reception time point of the signal from the one or more devices.

8. The apparatus of claim 1, wherein the apparatus is configured to: A further side link signal is broadcasted to the set of devices, the further side link signal including one of: an identity of the apparatus or an identity of the target device.

9. The apparatus of claim 1, wherein the apparatus is configured to: A configuration of a resource selection window is obtained according to the transmission time window.

10. The apparatus of claim 1, wherein the apparatus is configured to: receiving the request for reference signal transmission alignment from the target device; or The request for reference signal transmission alignment is received from another device that is a server terminal device or a network node.

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