Systems and methods for estimating direction from one UE to another UE using sidelink links

Abstract

A method for estimating a direction from a first user equipment (UE) to a second UE, the first UE and the second UE being connectable to a communication network, the method comprising: determining a signal, SL-PDS, based on a first sidelink position transmitted on a sidelink of the communication network between the first UE and the second UE, obtaining a first estimated distance between the first UE and the second UE; obtaining a second estimated distance between the first UE and a first secondary node associated with the communication network based on a second position determination signal (PDS) transmitted between the first UE and the first secondary node; obtaining a third estimated distance between the second UE and the first auxiliary node based on a third PDS transmitted between the second UE and the first auxiliary node; and estimating a direction from the first UE to the second UE based on the first estimated distance, the second estimated distance, and the third estimated distance.

Description

Technical Field

[0001] The present invention generally relates to estimating a direction from one user equipment (UE) to another user equipment relying at least in part on direct communication. In some embodiments of the present invention, the direct communication occurs over a PC5 interface. Background Art

[0002] A modern UE is typically not able to estimate the distance and direction of another UE relative to its own position. However, as described in RP-213588: "Revised SID in Extended and Improved NR Positioning Study", it would be beneficial to be able to provide at least a rough estimate of the relative position of UEs with respect to each other given the multiple functions that modern UEs are expected to perform. One way to achieve distance estimation may be to exchange reference signals via direct communication between UEs. An exemplary mode of direct communication is sidelink communication via a PC5 interface, as defined, for example, in 3GPP Technical Specifications 38.211 Chapter 8, 38.212 Chapter 8, 38.213 Chapter 16 and 38.214 Chapter 8 for RAN1 (all RAN1 Technical Specifications Version 17.1.0) and 38.331 Chapter 5.8 for RAN2 (Version 17.0.0).

[0003] Figure 1 2 shows the two-dimensional results of distance estimation based on the reference signal exchange between UE 101 and UE 102. It can be seen that UE 101 can estimate the relative distance to UE 102 based on the reference signal exchange. However, UE 101 cannot estimate the direction from itself to UE 102. From the point of view of UE 101, UE 102 can be located anywhere on a circle around UE 101, the radius of which is the estimated distance between UE 101 and UE 102. This is explained by Figure 1 1 is shown as a box with a dashed outline. Any of the three exemplary instances may be the actual location of UE 102 relative to UE 101. However, UE 101 cannot identify the actual relative location of UE 102. Figure 1 The two-dimensional results of the current estimation of the relative position are shown, so it should be understood that, in fact, when the third dimension is considered, UE 102 can be located anywhere on multiple circles centered on UE 101, where one circle is at Figure 1 A. Thus, UE 102 may be located anywhere on the surface of a sphere having a radius corresponding to the estimated distance from UE 101 to UE 102.

[0004] The UE may be incorporated into a cell phone, terminal, IoT device, extended sensor, or vehicle, etc., or the UE itself may be a cell phone, terminal, IoT device, extended sensor, or vehicle, etc. In particular, in the case of vehicles, for example for the purposes of vehicle platooning, advanced driving, and remote driving, when estimating the relative position of the UEs to each other, it would be beneficial if the UEs knew the relative direction in addition to the relative distance. Of course, the benefits of knowing the relative direction are not limited to vehicles.

[0005] In addition to being unable to estimate direction, current UEs are only able to estimate the distance between them if direct communication via a line of sight (LOS) link is available. Therefore, for current UEs, the estimation of their relative position to each other is limited to the distance estimation based on the LOS link.

[0006] It is therefore an object of the present invention to improve the way in which UEs estimate their relative position with respect to each other, so that they know their relative direction without having to rely on LOS links. Summary of the invention

[0007] To achieve this purpose, the present invention provides a method for estimating the direction from a first UE to a second UE, the first UE and the second UE being able to connect to a communication network. The method comprises the following steps: obtaining a first estimated distance between the first UE and the second UE based on a first sidelink position determination signal SL-PDS transmitted on a sidelink between the first UE and the second UE of the communication network; obtaining a second estimated distance between the first UE and the first auxiliary node based on a second position determination signal PDS transmitted between the first UE and a first auxiliary node associated with the communication network; obtaining a third estimated distance between the second UE and the first auxiliary node based on a third PDS transmitted between the second UE and the first auxiliary node; and estimating the direction from the first UE to the second UE based on the first estimated distance, the second estimated distance and the third estimated distance.

[0008] In addition, the present invention provides a computer-readable medium, which includes instructions for enabling one or more processors of at least one of a first UE, a second UE, a first and a position control node to estimate the direction from the first UE to the second UE by performing the following steps, wherein the first UE and the second UE are capable of connecting to a communication network: obtaining a first estimated distance between the first UE and the second UE based on a first sidelink position determination signal SL-PDS transmitted on a sidelink between the first UE and the second UE of the communication network; obtaining a second estimated distance between the first UE and the first auxiliary node based on a second position determination signal PDS transmitted between the first UE and a first auxiliary node associated with the communication network; obtaining a third estimated distance between the second UE and the first auxiliary node based on a third PDS transmitted between the second UE and the first auxiliary node; and estimating the direction from the first UE to the second UE based on the first estimated distance, the second estimated distance and the third estimated distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Embodiments of the Invention Embodiments of the present invention will be described, wherein like reference numerals denote like elements.

[0010] Figure 1 is an example of a UE's estimation of a relative position according to the prior art.

[0011] Figure 2 are examples of direct communication between UEs and a communication network, which alone or in combination respectively enable estimation of a direction from a first UE to a second UE.

[0012] Figure 3 is an example of a base station according to an embodiment of the present invention.

[0013] Figure 4 is an example of a UE according to an embodiment of the present invention.

[0014] Figure 5 is an example of a position monitoring function according to an embodiment of the present invention.

[0015] FIG. 6A to FIG. 6C A method for estimating a direction from a first UE to a second UE according to an embodiment of the present invention is shown.

[0016] 7A to 7C Provides how to use according to embodiments of the present invention FIG. 6A to FIG. 6C An example of a method.

[0017] Fig. 8A and Figure 8B According to an embodiment of the present invention, how to use the LOS link if it is not available for at least some UEs or nodes is respectively provided. FIG. 6A to FIG. 6CAn example of a method.

[0018] Fig.9A and Fig. 9B The following respectively show which UEs or nodes can perform the following operations according to the embodiments of the present invention. FIG. 6A to FIG. 6C certain steps of the method.

[0019] It should be understood that these drawings are by no means intended to limit the disclosure of the present invention. On the contrary, these drawings are provided to help understand the present invention. It will be readily understood by those skilled in the art that the various aspects of the present invention shown in one drawing may be combined with the various aspects in another drawing, or may be omitted without departing from the scope of the present invention. DETAILED DESCRIPTION

[0020] The present disclosure generally provides a method for estimating the direction from a first UE to a second UE. In order to estimate the direction, an auxiliary node is included to obtain three estimated distances, namely, the distance from the first UE to the second UE and to the auxiliary node and from the second UE to the auxiliary node. The auxiliary node can be a UE similar to the first UE and the second UE, or it can be a node of a communication network. Using these three estimated distances, the direction from the first UE to the second UE can be estimated. In the case of the first estimated distance (i.e., the distance from the first UE to the second UE), the distance is obtained based on a first sidelink position determination signal (SL-PDS), which is a signal that enables the position of the second UE relative to the first UE to be determined using direct communication between the first UE and the second UE (e.g., communication through a PC5 interface). The second estimated distance and the third estimated distance are obtained based on the second PDS and the third PDS, i.e., the estimated distance between the first UE and the auxiliary node and the estimated distance between the second UE and the auxiliary node. The first PDS and the second PDS are both signals that can determine the relative position of each entity relative to each other. The second PDS and the third PDS can be transmitted via a communication network, or transmitted via direct communication like the first SL-PDS. In the latter case, the second PDS and the third PDS may also be referred to as a second SL-PDS and a third SL-PDS.

[0021] In summary, the method for estimating the direction from the first UE to the second UE is generally based on the inclusion of an auxiliary node and estimating the distances between the three entities based on signaling between the three entities, wherein at least the signaling between the first UE and the second UE is based on direct communication. In the case where the auxiliary node is also a UE, the method can rely entirely on direct communication and can therefore be independent of the communication network. By incorporating an auxiliary node to estimate the direction, the method can use a specific auxiliary node that has a LOS link with the first UE and the second UE. In addition, if the first UE does not have a LOS link with the second UE, one or more additional auxiliary nodes can be included, so that at least three estimated distances based on the LOS link can be obtained.

[0022] The general concept of a method for estimating a direction from a first UE to a second UE will now be discussed in detail with reference to the accompanying drawings.

[0023] Figure 2 A cellular communication network 100 is schematically shown. Figure 2 The example of FIG. 1 shows a communication network 100 according to the 3GPP 5G architecture. Details of the 3GPP 5G architecture are described in 3GPP TS 23.501, version 17.4.0. Figure 2 The following and other parts of the description illustrate technologies in the 3GPP 5G framework of cellular networks, but similar technologies can be easily applied to other communication networks. Examples include, for example, IEEE Wi-Fi technology.

[0024] exist Figure 2 In the case of a cellular communication network 100, the first UE 101 can be connected to the cellular communication network 100. Throughout the discussion of the present invention, UE can refer to any type of user equipment, including but not limited to a cellular phone, an IoT device, a traffic infrastructure device such as a traffic light or a variable message sign (VMS), an eCall or In other words, a UE may refer to any type of device that can be connected to a communication network and that requires direction estimation for some part of the functionality of another UE.

[0025] The first UE 101 may be connected to the network 100 via a radio access network (RAN) 111, which is typically formed by one or more base stations (BSs), such as BSs 112a and 112b (for simplicity, the BSs are shown in FIG. Figure 2Only two BSs are shown; the BSs implement access nodes (ANs). Depending on the standard implemented by the communication network 100, the BSs may also be referred to as eNBs, gNBs, or transmission and reception points (TRPs). A wireless link 114 is established between the RAN 111 (particularly one or more BSs 112 in the RAN 111) and the UE 101. The wireless link 114 is defined by one or more OFDM carriers. BSs 112a and 112b may also be referred to as auxiliary nodes.

[0026] Figure 2 Also shown are a second UE 102 and an auxiliary UE 103. Both the second UE 102 and the auxiliary UE 103 correspond to the UE 101 in terms of their functionality. Therefore, the above discussion of the first UE 101 is applicable to the second UE 102 and the auxiliary UE 103. For simplicity, the connections of the UE 102 and UE 103 to the RAN 111 are omitted. The auxiliary UE 103 may also be referred to as an auxiliary node.

[0027] The first UE 101, the second UE 102 and the third UE 103 may also be connected to each other for direct communication, as shown by connection 150. Connection 150 may be established through a PC5 interface, i.e. via sidelink communication (e.g. as defined in 3GPP Technical Specifications 38.211 Chapter 8, 38.212 Chapter 8, 38.213 Chapter 16 and 38.214 Chapter 8 for RAN1 (all RAN1 Technical Specifications Version 17.1.0) and 38.331 Chapter 5.8 for RAN2 (Version 17.0.0)). It should be noted that sidelink communication is possible even if none of UE 101, UE 102 and UE 103 is connected to the communication network 100.

[0028] RAN 111 is connected to core network (CN) 115. CN 115 includes user plane (UP) 191 and control plane (CP) 192. Application data is usually routed via UP 191. For this purpose, UP function (UPF) 121 is provided. UPF 121 can implement a router function. Application data can pass through one or more UPF 121. Figure 2 In the case of a UE 101, UPF 121 acts as a gateway to a data network (DN) 180 (eg, the Internet or a local area network). Application data may be transmitted between UE 101 and one or more servers on DN 180.

[0029] The communication network 100 also includes an access and mobility management function (AMF) 131; a session management function (SMF) 132; a policy control function (PCF) 133; an application function (AF) 134; a network slice selection function (NSSF) 134; an authentication server function (AUSF) 136; a unified data management (UDM) 137; and a location management function (LMF) 139. Figure 2 Also shown are the protocol reference points N1 - N22 between these nodes.

[0030] AMF 131 provides one or more of the following functions: registration management; NAS termination; connection management; reachability management; mobility management; access authentication; and access authorization. If the first UE 101 operates in connected mode, a data connection 189 is established by AMF 131. Connection 189 is established by AMF 131 for the second UE 102 and the secondary UE 103, but for simplicity in FIG. Figure 2 Connection 189 is omitted.

[0031] SMF 132 provides one or more of the following functions: session management, including session establishment, modification and release, including the establishment of UP bearers between RAN 111 and UPF 121; UPF selection and control; configuration of traffic diversion; roaming functions; at least part of the termination of NAS messages. Therefore, both AMF 131 and SMF 132 implement CP mobility management required to support mobile UEs.

[0032] The data connection 189 is established between the first UE 101 and the data plane 191 of the CN 115 via the RAN 111 and towards the DN 180. For example, a connection with the Internet or another packet data network can be established. In order to establish the data connection 189, the first UE 101 can perform a random access (RA) procedure, for example, in response to receiving a paging indicator or a paging message and an optional previous wake-up signal (WUS). The server of the DN 180 can host a service that transmits payload data via the data connection 189. The data connection 189 may include one or more bearers, such as a dedicated bearer or a default bearer. The data connection 189 may be defined at a radio resource control (RRC) layer (e.g., layer 3 of the OSI model, which is typically layer 2).

[0033] The LMF 139 (also referred to as a location control node) processes location service requests. This may include transmitting assistance data to the first UE 101 to be positioned to assist UE-based positioning and / or UE-assisted positioning, and / or may include positioning of the first UE 101. See 3GPP TS 38.305, Section 5.1, Version 17.0.0. For downlink (DL) positioning using PRS, the LMF 139 may initiate a positioning procedure using a positioning protocol with the first UE 101, for example, to obtain a position estimate or positioning measurements or to transmit positioning assistance data to the first UE 101. The location service request processed by the LMF 139 may also include a request to estimate the direction from the first UE 101 to the second UE 102.

[0034] Figure 3 BS112a and 112b are schematically shown. BS112 includes an interface 1121. For example, interface 1121 may include an analog front end and a digital front end. Interface 1121 may support a variety of signal designs, such as different modulation schemes, coding schemes, modulation digital schemes, and / or multiplexing schemes. BS112 also includes a control circuit 1122 implemented, for example, by one or more processors and software. For example, the program code to be executed by the control circuit 1122 may be stored in a non-volatile memory 1123. In various examples disclosed herein, various functions may be implemented by the control circuit 1122, such as estimating the direction from the first UE 101 to the second UE 102, as will be further referenced FIG. 6A to FIG. 6C For example, in one embodiment, the functions implemented by the control circuit 1122 may be functions of an auxiliary node.

[0035] Figure 4 A first UE 101, a second UE 102, and an auxiliary UE 103 are schematically shown. The UE includes an interface 1011. For example, the interface 1011 may include an analog front end and a digital front end. The UE also includes a control circuit 1012 implemented, for example, by one or more processors and software. The control circuit 1012 may also be at least partially implemented in hardware. For example, a program code to be executed by the control circuit 1012 may be stored in a non-volatile memory 1013. In various examples disclosed herein, various functions may be implemented by the control circuit 1012. Such functions may include estimating a direction from the first UE 101 to the second UE 102 based on transmitting a first SL-PDS, a second PDS, and a third PDS via the interface 1011.

[0036] Figure 5 Schematically shows the reference Figure 2The example LMF 139 discussed. The LMF 139 includes an interface 1391 for communicating with other nodes of the CN 115 or with the RAN 111 of the cellular network 100. The LMF 139 also includes a control circuit 1392 implemented, for example, by one or more processors and software. For example, program code to be executed by the control circuit 1392 may be stored in a non-volatile memory 1393. In various examples disclosed herein, various functions may be implemented by the control circuit 1392, such as referring to FIG. 6A to FIG. 6C A method for estimating a direction from a first UE 101 to a second UE 102 is discussed.

[0037] FIG. 6A to FIG. 6C A method 600 for estimating a direction from a first UE 101 to a second UE 102 is shown. FIG. 6A to FIG. 6C In the embodiment, the steps shown in the dotted box are used to indicate optional steps. Some of these optional steps (e.g., steps 621 to 623) are optional parts of a step (e.g., step 620), as shown in these steps shown in the boxes of the corresponding steps.

[0038] Steps 601 to 690 will be FIG. 6A to FIG. 6C 101 to the second UE 102. The steps 620 to 655 are discussed in the order shown. However, those skilled in the art will appreciate that this description is by no means meant to imply that these steps need to be performed in this order. Instead, these steps may be performed in any order suitable for estimating the direction from the first UE 101 to the second UE 102. For example, steps 620 to 655 may be performed simultaneously in the reverse order shown or in a completely different order (e.g., first step 640, then steps 620, 655, 630, and 650). In addition, step 660 may be performed, for example, before steps 620 to 655.

[0039] In step 601, the method 600 may establish a request to estimate the direction from the first UE 101 to the second UE 102. The request may be established within the first UE 101, for example by another function executed within the control circuit 1012, such as an autonomous driving function. The request may be established by the first UE 101 and sent to the second UE 102 and / or the auxiliary UE 103 directly or via the communication network 100. The request may be established by an entity of the communication network 100 (e.g., LMF 139) in response to a location service request. In some embodiments, the method 600 may skip step 601 and estimate the direction from the first UE 101 to the second UE 102 without establishing a request.

[0040] In step 610, the method 600 may configure a SL-PDS configuration for at least the first UE 101 or the second UE 102, where the SL-PDS configuration is used to configure a sidelink position determination signal SL-PDS.

[0041] In the context of the present application, SL-PDS refers to any type of signal that is capable of determining the position of one UE (e.g., the second UE 102) relative to another UE (e.g., the first UE 101) using any type of direct communication between two UEs. Although the description refers to such a signal as SL-PDS, it should be clear that the name of the signal can be replaced by any other suitable expression, such as Sidelink Position Reference Signal (SL-PRS) or Sidelink Reference Signal (SL-RS). Direct communication refers to direct communication between UEs without routing through the communication network 100. As described above, one such type of direct communication is direct communication via the PC5 interface, commonly referred to as a sidelink, and Figure 2 1 is shown by connection 150. Of course, other types of direct communications may be used in place of or in combination with sidelink communications, such as Bluetooth Low Energy (BLE) or Wi-Fi.

[0042] In some embodiments, the SL-PDS configuration may be transmitted from an access node (e.g., RAN 111) or a location control node (e.g., LMF 139) of the communication network 100 to the first UE 101 or the second UE 102. In some embodiments, the SL-PDS configuration may also be transmitted from these entities to assist the UE 103.

[0043] In some embodiments, the SL-PDS configuration may be communicated between the first UE 101 and the second UE 102 using control signaling on the sidelink 150. For example, the SL-PDS configuration may be included in a Sidelink Broadcast Control Channel (SBCCH) or a Sidelink Control Information (SCI) signal.

[0044] In some embodiments, the SL-PDS configuration may include at least one of the transmission timing of the SL-PDS, the time-frequency resources allocated to the SL-PDS by the communication network 100, the transmission power of the SL-PDS, the beam configuration of the SL-PDS, the sequence design of the SL-PDS, at least one report item for reporting the exchange of the SL-PDS between the first UE 101 and the second UE 102, the time point for sending the first SL-PDS, or the time interval for sending the first SL-PDS. All of these configuration items may enable the estimation of the distance between the first UE 101, the second UE 102, and the auxiliary node, as will be discussed below.

[0045] In some embodiments, SL-PDS configuration may not be required because both the first UE 101 and the second UE 102 are aware of the SL-PDS configuration, for example because the SL-PDS configuration is predetermined or determined by the UE based on predetermined factors, such as the mobility of the UE or the characteristics of previous sidelink communications between the UEs.

[0046] In step 620 , the method 600 obtains a first estimated distance between the first UE 101 and the second UE 102 based on a first SL-PDS transmitted on the sidelink 150 of the communication network 100 .

[0047] The first distance may be estimated based on any distance estimation method capable of estimating a distance based on an exchange of signals (ie, in the case of the first estimated distance, the first SL-PDS).

[0048] In some embodiments, the distance estimation method may be a one-way ranging or a round-trip measurement, i.e., the method may be based only on the reception of the first SL-PDS, or may be based on receiving an indication of the reception of the first SL-PDS at the transmitter of the first SL-PDS, such as an acknowledgment (ACK) signal from the receiver of the first SL-PDS. In some embodiments, the distance estimation method may be based on the reception of SL-PDS in both directions.

[0049] In some embodiments, the distance estimation method can be based on measuring one of signal strength, angle, or time. Therefore, the distance can be measured based on the signal strength of the first SL-PDS, the angle (such as the angle of arrival (AoA) or the angle of departure (AoD) of the first SL-PDS), or the time between the transmission and reception of the first SL-PDS. More specifically, in some embodiments, the measurement result can be one of the reference signal received power (RSRP), the arrival time difference (TDOA), or the time difference between the transmitter and the receiver.

[0050] In some embodiments, the method 600 may specifically include step 623, which estimates the first estimated distance based on the reception properties of the first SL-PDS exchanged between the second UE 102 and the first UE 101. Therefore, the estimate of the first distance may be estimated based on the measurement of the properties of the received first SL-PDS.

[0051] The measured attribute may be the received signal strength of the first SL-PDS. For example, the SL-PDS may be defined to have a reference signal strength. Thus, the distance estimation may be based on the difference between the received signal strength and the reference signal strength. To this end, the transmit power of the SL-PDS may be defined in the SL-PDS configuration.

[0052] The measured attribute may be a propagation time. In the case of one-way ranging, the propagation time corresponds to the time taken to receive the first SL-PDS after sending the first SL-PDS. In the case of a round-trip measurement, the propagation time corresponds to the time taken for the transmitter of the first SL-PDS to receive an ACK message from the receiver of the first SL-PDS. In another example, the round-trip measurement is measured based on the sending and receiving of the SL-PDS in two directions. In both cases, the first distance can be estimated based on the elapsed time. To this end, any one of the transmission timing of the SL-PDS, the time-frequency resources allocated to the SL-PDS, the time point at which the first SL-PDS is sent, at least one report item for reporting the exchange of the SL-PDS between the first UE 101 and the second UE 102, and the time interval at which the first SL-PDS is sent may be defined in the SL-PDS configuration.

[0053] The measured attribute may be a timestamp indicating the transmission time of the first SL-PDS or a timestamp indicating that a trigger message is received at the transmitter of the first SL-PDS. To this end, in an embodiment where the first UE 101 and the second UE 102 are connected to the communication network 100, the two UEs may be synchronized with the clock of the communication network 100. In an embodiment where the first UE 101 and the second UE 102 are not connected to the communication network 100, the two UEs may negotiate or define a synchronized clock via an SCI signal of the side link 150 or some other control signaling.

[0054] The measured attribute may be the AoA of the first SL-PDS. For example, if the interface 1011 of the receiving UE includes an antenna array, the AoA may be determined based on the phase difference received at each element in the antenna array. The measured attribute may be the angle of departure (AoD). For example, if the interface 1011 of the transmitting UE is capable of beam scanning, the receiving UE may determine the AoD based on identifying the strongest beam received at the receiving UE. In either case, an estimated first distance may be obtained from the corresponding angle. This may be achieved, for example, if the AoD or AoA is known for one node, such as a first auxiliary node, from the perspective of two other nodes, such as the first UE 101 and the second UE 102. To this end, any one of the beam configuration of the SL-PDS and the sequence design of the SL-PDS may be defined in the SL-PDS configuration.

[0055] In some embodiments, the reception attribute is used at the receiver to estimate the first distance. Thus, in an embodiment where the first SL-PDS is sent from the second UE 102 to the first UE 101, the first UE 101 estimates the first distance. In some embodiments, the reception attribute is transmitted to another entity (e.g., a location control such as LMF 139 of the communication network 100) for estimating the first distance.

[0056] In one embodiment, the first SL-PDS is transmitted from the second UE 102 to the first UE 101. In one embodiment, the first SL-PDS is transmitted from the first UE 101 to the second UE 102. Therefore, either the first UE 101 or the second UE 102 may measure properties of the received first SL-PDS.

[0057] In some embodiments, obtaining the first estimated distance may include step 621, which triggers the exchange of a first SL-PDS between the second UE 102 and the first UE 101 on a first sidelink communication channel established between the first UE 101 and the second UE 102 on the sidelink 150 of the communication network 100. In other words, the exchange of the first SL-PDS may be triggered using sidelink data during sidelink data transmission.

[0058] In some embodiments, obtaining the first estimated distance may include step 622, which uses a broadcast transmission of at least one of the first UE 101 and the second UE 102 to trigger an exchange of a first SL-PDS between the second UE 102 and the first UE 101. In other words, one of the first UE 101 and the second UE 102 may use a sidelink broadcast channel (SL-BCH) to trigger the exchange of the SL-PDS.

[0059] In some embodiments, triggering the exchange of the first SL-PDS may define the configuration of the first SL-PDS. To define such a configuration, Figure 6C As shown, steps 621 and 622 may also include step 621a, which provides a trigger message to at least one of the first UE 101 and the second UE 102, and the trigger message defines the initiator and the receiver of the first SL-PDS. In some embodiments, the initiator may be the second UE 102, and the receiver may be the first UE 101. In some embodiments, the initiator may be the first UE 101, and the receiver may be the second UE 102. It should be noted that in some embodiments, the entity that triggers the exchange may not be either the initiator or the receiver of the first SL-PDS. The configuration of the SL-PDS may also include a LOS indication, which may be used to determine the reliability of the estimate of the first distance.

[0060] In addition, if Figure 6C As shown in , both step 621 and step 622 may further include step 621b, which may define (as part of the trigger message or independently) the distance estimation method used to estimate the first estimated distance. Thus, triggering the exchange may provide instructions to identify the distance estimation method to be used and what information should be provided to enable the corresponding distance estimation method. Those skilled in the art will appreciate that the trigger message may also include any other information required to estimate the first distance based on the selected distance estimation method.

[0061] In step 630, method 600 obtains a second estimated distance between the first UE 101 and the first auxiliary node associated with the communication network 100 based on a second PDS transmitted between the first UE 101 and the first auxiliary node. Similar to the first estimated distance at step 620, the second distance can be estimated based on any distance estimation method that enables the distance to be estimated based on the exchange of signals (i.e., the second PDS in the case of the second estimated distance). It should be noted that in some embodiments, the distance estimation method for estimating the first distance may be the same as the method for estimating the second distance. However, in some embodiments, the distance estimation method for estimating the first distance may be different from the method for estimating the second distance. The distance estimation method for estimating these two distances depends on the capabilities of the communication links between the various entities and the capabilities of the various interfaces used to connect to the various communication links. It is obvious to those skilled in the art that additional or other factors that determine the selection of the distance estimation method may be considered.

[0062] In some embodiments, the first auxiliary node may be an auxiliary UE 103. In some embodiments, the first auxiliary node may be a node of the communication network 100, such as BS 112a or BS 112b. In general, the first auxiliary node may be any node that enables estimation of the second distance and the third distance, which will be discussed with respect to step 640, in order to allow estimation of the direction from the first UE 101 to the second UE 102. Thus, the auxiliary node may be any node that is capable of exchanging signals that enable estimation of the distance from the auxiliary node to the first UE 101 and to the second UE 102.

[0063] Similar to the first SL-PDS, the second PDS involves any type of signal that enables the position of the first auxiliary node relative to the first UE 101 to be determined. However, unlike the first SL-PDS, the second PDS can be sent via other communication channels other than direct communication. The second PDS can, for example, be routed through the communication network 100 to reach the UE 101, for example via a Uu interface, such as the wireless connection 114. Of course, if the first auxiliary node is an auxiliary UE (e.g., an auxiliary UE 103), the second PDS can be exchanged via direct communication (e.g., via the second sidelink 150) like the first SL-PDS. In this case, the second PDS may also be referred to as a second SL-PDS. It should be noted that although the present application refers to the signal that enables the position of the first auxiliary node relative to the first UE 101 to be determined as a second PDS, the signal may also be referred to as a second PRS or a second RS or any other suitable expression.

[0064] Step 630 may also include step 631, which triggers the exchange of a second PDS between the first UE 101 and the first auxiliary node. Step 631 corresponds to step 621, where the second PDS replaces the first SL-PDS and the first auxiliary node replaces the second UE 102. In an embodiment where the first auxiliary node is not an auxiliary UE, downlink control information (DCI) and uplink control information (UCI) replace SCI. To avoid repetition, similar parts of the description of step 621 are not repeated here. In addition, similar to step 621, step 631 may include Figure 6C Steps 621a and 621b are shown.

[0065] Although in Fig. 6A Although not shown in FIG. 6 , step 630 may include a step corresponding to step 622, i.e., the second PDS may be exchanged using broadcast transmission. If the first auxiliary node is not an auxiliary UE, the transmission may be performed on a broadcast channel BCH. If the first auxiliary node is an auxiliary UE, the transmission may be performed on a SL-BCH.

[0066] Step 630 may further include step 632, which estimates a second estimated distance based on a reception property of a second PDS exchanged between the first auxiliary node and the first UE 101. Step 632 corresponds to step 623, where the second PDS replaces the first SL-PDS and the first auxiliary node replaces the second UE 102. To avoid repetition, the description of step 623 is not repeated here.

[0067] At step 640, the method 600 obtains a third estimated distance between the second UE 102 and the first auxiliary node associated with the communication network based on a third PDS transmitted between the second UE 102 and the first auxiliary node. Step 640 corresponds to step 630, wherein the third estimated distance replaces the second estimated distance and the first UE 101 is replaced by the second UE 102. To avoid repetition, similar parts of the description of step 630 are not repeated here.

[0068] It should be noted that although the present application refers to the signal enabling determination of the position of the first auxiliary node relative to the second UE 102 as a third PDS, the signal may also be referred to as a third PRS or a third RS or any other suitable expression.

[0069] Step 640 may further include step 641, which triggers the exchange of a second PDS between the second UE 102 and the first auxiliary node. Step 641 corresponds to step 621, wherein the third PDS replaces the first SL-PDS, the first auxiliary node replaces the second UE 102, and the second UE 102 replaces the first UE 101. In an embodiment where the first auxiliary node is not an auxiliary UE, downlink control information (DCI) and uplink control information (UCI) replace SCI. To avoid repetition, similar parts of the description of step 621 are not repeated here. In addition, similar to step 621, step 641 may include Figure 6C Steps 621a and 621b are shown.

[0070] Although in Fig. 6A Although not shown in FIG. 6 , step 640 may include a step corresponding to step 622, i.e., the third PDS may be exchanged using broadcast transmission. If the first auxiliary node is not an auxiliary UE, the transmission may be performed on the BCH. If the first auxiliary node is an auxiliary UE, the transmission may be performed on the SL-BCH.

[0071] Step 640 may further include step 642, which estimates a third estimated distance based on a reception property of a third PDS exchanged between the first auxiliary node and the second UE 102. Step 642 corresponds to step 623, wherein the third PDS replaces the first SL-PDS, the first auxiliary node replaces the second UE 102, and the second UE 102 replaces the first UE 101. To avoid repetition, the description of step 623 is not repeated here.

[0072] Steps 620, 630 and 640 and more specifically steps 621, 631 and 641 are Fig. 6Aare shown as occurring successively to each other. However, although in some embodiments, the exchange of the first SL-PDS, the second PDS, and the third PDS may actually be triggered subsequently, they may also be triggered simultaneously. In addition, each trigger message may define the same transmission timing for the first SL-PDS, the second PDS, and the third PDS, resulting in simultaneous or near-simultaneous transmission of the first SL-PDS, the second PDS, and the third PDS. In addition, each trigger message may define the same time interval for the first SL-PDS, the second PDS, and the third PDS, that is, the three signals may be sent at similar times. In the case of a mobile UE (e.g., an autonomous driving unit), it may be advantageous to define the same timing interval. In some embodiments, any information about the transmission time of the first SL-PDS, the second PDS, and the third PDS may be omitted, in which case the three signals may be transmitted on the next available pre-configured time resource.

[0073] In some embodiments, steps 621, 631, and 641 may be performed by the first UE 101. For example, the first UE 101 may broadcast a trigger message to the second UE 102 and the first auxiliary node. Alternatively, the first UE 101 may send a trigger message to the second UE 102 and the first auxiliary node. In some embodiments, steps 621, 631, and 641 may be performed by a location control node (such as LMF 139) of the communication network 100 or another node (such as RAN 111) of the communication network 100. As in the case where these steps are triggered by the first UE 101, the LMF 139 or the RAN 111 may broadcast a trigger message, or may send a trigger message to the first UE 101, the second UE 102, and the first auxiliary node.

[0074] The method 600 may further include steps 650 and 655, wherein step 650 obtains a fourth estimated distance between the first UE 101 and the second auxiliary node based on the fourth PDS, and step 655 obtains a fifth estimated distance between the second UE 102 and the second auxiliary node based on the fifth PDS. The second auxiliary node is similar to the first auxiliary node, and may be, for example, an auxiliary UE 103 or a node of the communication network 100, such as BS112a or BS112b. Although steps 650 and 655 refer to the signal enabling determination of the position of the second auxiliary node relative to the first UE 101 as the fourth PDS, and the signal enabling determination of the position of the second auxiliary node relative to the second UE 102 as the fifth PDS, these signals may also be referred to as the fourth and fifth PRSs or the fourth and fifth RSs, respectively, or any other suitable expressions. Steps 650 and 655 correspond to steps 620, 630, and 640, and their descriptions are not repeated here to avoid repetition.

[0075] In step 660, the method 600 may select a first auxiliary node from a plurality of candidate nodes. The candidate node may be, for example, another UE that may establish direct communication with the first UE 101, or may be a node of the communication network 100 that may establish communication with the first UE 101 via the communication network 100, such as BS 112a and BS 112b. In general, the candidate node may be any node that is suitable for assisting in estimating the direction from the first UE 101 to the second UE 102.

[0076] In some embodiments, step 660 may depend on a plurality of predetermined distances between the first UE 101 and each of the plurality of candidate nodes. For example, the distances of the plurality of candidate nodes may be estimated in advance, for example, according to the distance estimation method discussed with reference to step 620. In some embodiments, the first auxiliary node may then be selected from these nodes based on the shortest estimated distance.

[0077] In some embodiments, step 660 may also depend on a plurality of additional predetermined distances between the second UE 102 and each of the plurality of candidate nodes, the plurality of additional predetermined distances being obtained from distance observations different from the plurality of predetermined distances. For example, the distances of the plurality of candidate nodes to the second UE 102 may be estimated in advance, for example, according to the distance estimation method discussed with reference to step 620. These distances from each candidate node to the second UE 102 are then compared with the corresponding distances from each candidate node to the first UE 101. The first auxiliary node may then be selected based on the shortest distances to the first UE 101 and to the second UE 102.

[0078] In addition to or in lieu of selecting the first auxiliary node from a plurality of candidate nodes based on the estimated distances from the first UE 101 and the second UE 102 to the candidate node, step 660 may also select the first auxiliary node based on another criterion. For example, in an embodiment where the communication network 100 is a cellular network, the first auxiliary node may be selected based on the cell in which the first auxiliary node is located. In some embodiments, the list of candidate nodes may be predetermined based on the cell in which the candidate node is located to reduce the number of required distance estimates. In some embodiments, the first auxiliary node may be selected based on the mobility level of the candidate node. For example, the first auxiliary node may be selected based on no mobility or limited mobility, i.e., a fixed node (e.g., BS112a or BS112b) or a low mobility UE (e.g., an anchor UE, a roadside unit (RSU) or a VMS) of the communication network 100. In some embodiments, the first auxiliary node may be selected based on no or limited relative mobility, i.e., the first auxiliary node may be an auxiliary UE moving at a similar or same speed as the first UE 101. In some embodiments, the mobility level may also be used to determine multiple candidate nodes to reduce the number of required distance estimates. In some embodiments, the received signal strength may be used to select the first auxiliary node or to predetermine a plurality of candidate nodes. In some embodiments, a plurality of candidate nodes may be predetermined based on a LOS indication received from each candidate node.

[0079] If steps 650 and 655 of method 600 are performed, step 660 may additionally select a second auxiliary node in the same manner as the first auxiliary node. In the context of the second auxiliary node, step 660 may also determine that it may be beneficial to use the second auxiliary node based on the auxiliary node selection criteria discussed above. For example, when selecting the first auxiliary node, step 660 may determine that estimating the second distance and the third distance based on any one of a plurality of candidate nodes may not be accurate enough. This determination may be based, for example, on an LOS indication from a candidate node, a signal strength of a candidate node, a mobility level of a candidate node, and / or a predetermined positioning accuracy requirement. Those skilled in the art will appreciate that other or additional factors may affect the determination. In this case, after making the determination, step 660 may select a second auxiliary node, thereby triggering the execution of steps 650 and 655. Therefore, step 660 may be performed before steps 650 and 655. In some embodiments, it may be determined before step 660 that steps 650 and 655 are performed. The determination may be based, for example, on the same criteria as the criteria used by step 660 to determine the selection of the second auxiliary node discussed above. In this case, the second assisting node may be used to reliably estimate the direction from the first UE 101 to the second UE 102. Thus, step 660 may select the second assisting node without determining the need for the second assisting node.

[0080] As described above, selecting the first auxiliary node can be based on a predetermined distance between at least one of the first UE 101 and the second UE 102 and a plurality of candidate nodes. In some embodiments, steps 620 to 655 are effectively performed simultaneously, for example, simultaneously or within a specific time interval, to generate a predetermined distance. Then, step 660 determines whether to use all estimated distances or the first estimated distance, the second estimated distance, and the third estimated distance are sufficient to determine the direction. More generally, the method 600 can obtain various estimated distances, and step 660 can determine which of these distances is considered for the direction estimation in step 680. For example, the method 600 can first determine a plurality of candidate nodes based on the criteria discussed above, then obtain the estimated distances between the first UE 101, the second UE 102, and the candidate nodes, and then select the estimated distance to be considered in step 680. In other words, in some embodiments, step 660 can select the estimated distance.

[0081] The method 600 may include step 670, which obtains a report message indicating at least one of an estimated first distance, an estimated second distance, or an estimated third distance. In particular, in some embodiments, in addition to the corresponding estimated distance, the report message may include at least one report item, which is optionally specified by a trigger message defining an initiator and a receiver of the first SL-PDS or a corresponding one of the second and third PDSs.

[0082] As discussed above with respect to step 621, the trigger message may define that the first SL-PDS, the second PDS, and the third PDS include any information necessary to enable the distance estimation method to be used to estimate the corresponding distance. This information may be included in the report item of step 670. Exemplary report items include, but are not limited to, at least one of one or more distance estimation parameters, line of sight indication, receiver orientation, and receiver position for estimating the corresponding estimated distance. In some embodiments, the one or more distance estimation parameters include at least one of the reception properties of the first SL-PDS or at least one of the second PDS and the third PDS, received signal strength, arrival time difference, round-trip time, transmitter ID, receiver ID, arrival angle, departure angle, transmitter beam information, transmitter beam ID, receiver beam information, and receiver beam ID.

[0083] RSRP, TDOA, LOS indication, time measurements (e.g. based on timestamps or measured propagation delays), AoA measurements, AoD measurements, receiver orientation of their respective locations in the case of nearly static or low mobility nodes or UEs, trigger messages or transmitter beam information.

[0084] The report message may be obtained by a node performing distance estimation. Thus, in an embodiment where the first UE 101 estimates the first distance and estimates the direction, step 670 constitutes an intra-node operation with respect to the first UE 101 and the first estimated distance. In an embodiment where the direction is estimated by a local control node (e.g., LMF 139), the report message may be obtained by the local control node.

[0085] Method 600 includes step 680, which estimates the direction from the first UE to the second UE based on the first estimated distance, the second estimated distance, and the third estimated distance. In other words, the direction is estimated based on the azimuth. Step 680 can calculate the azimuth using the three estimated distances based on the following equation:

[0086]

[0087] In the above equation, θ is the estimated angle, d1 is the first estimated distance, d2 is the second estimated distance, and d3 is the third estimated distance. It should be understood that this equation only represents one option for calculating the direction estimate. Those skilled in the art will understand that other ways of estimating the direction based on at least three measured distances can be used.

[0088] More precisely, from the perspective of the first UE 101, θ represents the estimated angle between the first auxiliary node and the second UE 102. Fig. 7A , step 680 may define a two-dimensional coordinate system in which the first UE 101 is located at the center of the coordinate system and the second estimated distance forms part of the y-axis. Step 680 may also define the x-axis of the coordinate system to intersect the second estimated distance at 90°. Based on the correspondingly defined x-axis, step 680 may determine the direction from the first UE 101 to the second UE 102 by subtracting θ from 90°. Thus, by utilizing the ability to estimate the distance between the first UE 101, the second UE 102 and the auxiliary node to define a coordinate system centered on the first UE 101, the first UE 101 is able to estimate the direction from itself to the second UE 102. If the first UE 101 is moving, it may be particularly beneficial to estimate the direction based on the coordinate system centered on the first UE 101. One such scenario would be where the first UE 101, the second UE 102 and the auxiliary node are a platooning. In this case, any estimate of the direction based on other coordinate systems, particularly the global coordinate system or the coordinate system defined by the communication network 100, may be too unreliable.

[0089] Embodiments using other equations other than the equation defined above can, for example, use another estimated distance in the estimated distance as the axis of the coordinate system. In addition, such a reference coordinate system need not be two-dimensional. For example, two estimated distances in the estimated distance can be used to define two axes, and a third axis can be defined based on the two axes defined accordingly, so as to estimate the direction from the first UE 101 to the second UE 102.

[0090] To further refine the estimation of the direction from the first UE 101 to the second UE 102, step 680 may also use the above method to determine the height of the second UE 102 relative to the first UE 101. For example, step 680 may perform the above method by defining a horizontal coordinate system centered on the first UE 101 to estimate the direction horizontally, and may also perform the above method by defining a vertical coordinate system centered on the first UE 101 to estimate the direction (i.e., height) vertically.

[0091] In some embodiments, step 680 may be performed by the first UE 101. In some embodiments, step 680 may be performed by a node of the communication network 100, such as a location control node, such as LMF 139.

[0092] Finally, the method 600 may include a step 690 of reporting the estimated direction from the first UE 101 to the second UE 102. Step 690 may report the estimated direction to a node that requires the estimated direction for its function. For example, if the first UE 101 performs step 680, the first UE 101 may report the estimated distance to a process requesting the direction running on its control circuit 1012. If a location control node such as the LMF 139 performs step 680, and the UE 10 requires the estimated distance for some of its functions, the LMF 139 reports the estimated distance to the UE 101.

[0093] To better understand FIG. 6A to FIG. 6C method, FIG. 7A to FIG. 7C An example of how to estimate the direction from the first UE 101 to the second UE 102 is provided.

[0094] Fig. 7AA first UE 101, a second UE 102 and a first auxiliary node are shown, and the first auxiliary node can be, for example, one of the auxiliary UE 103, BS112a or BS112b. In addition, the first estimated distance, the second estimated distance and the third estimated distance obtained in steps 620, 630 and 640 are represented by lines d1, d2 and d3. The azimuth is represented by θ. Since d1, d2 and d3 form a triangle, the direction from the first UE 101 to the second UE 102 can be estimated in step 680 by performing the above trigonometric function.

[0095] Figure 7B Similar to Fig. 7A , but also includes the fourth estimated distance and the fifth estimated distance obtained in steps 650 and 655 (represented by lines d4 and d5). Therefore, Figure 7B A second auxiliary node is included, which can be, for example, one of the auxiliary UE 103, BS 112a or 112b. In this case, step 680 can be performed in a manner to obtain two azimuth angles θ1 and θ2. In such an embodiment, a more appropriate azimuth angle can be selected or used in combination based on the AoA or AoD measurement in step 623.

[0096] and Figure 7B similar, Figure 7C The estimated distances d1 to d5 are included, and a sixth estimated distance d6 from the first auxiliary node to the second auxiliary node is also included. Based on the additional sixth estimated distance, θ can be determined based on first calculating the other two angles of the triangle formed by the first UE 101, the second UE 102 and the second auxiliary node, and then based on the fact that the sum of the angles must be 180°.

[0097] Fig. 8A and Figure 8B Provides how to use the LOS link in the event that it is unavailable for at least some UEs or nodes. FIG. 6A to FIG. 6C An example of a method.

[0098] Corresponds to Figure 7B of Fig. 8A An example is shown where a LOS link is not available between the second UE 102 and the candidate node. Therefore, the candidate node is not selected in step 680, and thus the candidate distance d is not selected. c2 and d c3 Instead, only candidate nodes having LOS links to both the first UE 101 and the second UE 102 are selected in step 680 .

[0099] Corresponds to Figure 7C of Figure 8BAn example is shown in which the LOS link is not available between the first UE 101 and the second UE 102. Therefore, the method 600 determines that steps 650 and 655 should be performed to obtain the fourth distance and the fifth distance, thereby estimating the direction based on first obtaining the other two angles in the triangle formed by the first UE 101, the second UE 102, and the second auxiliary node via the triangle formed by the first UE 101, the first auxiliary node, and the second auxiliary node and the triangle formed by the second UE 102, the first auxiliary node, and the second auxiliary node.

[0100] Fig.9A and Fig. 9B The following respectively show which UEs or nodes can perform the following operations according to the embodiments of the present invention. FIG. 6A to FIG. 6C certain steps of the method.

[0101] Fig.9A A signaling diagram including a first UE 101, a second UE 102, a first auxiliary node (here represented as auxiliary UE 103 / BS 112a / BS 112b) and a RAN 111 is shown. Fig.9A , RAN 111 performs step 610 to provide configuration of the first SL-PDS, the second PDS and the third PDS to the first UE 101, the second UE 102 and the first auxiliary node, respectively. The first UE 101 performs steps 621, 631 and 641 to trigger the exchange of the first SL-PDS, the second PDS and the third PDS. The first UE 101 receives the first SL-PDS and the second PDS, and performs steps 623 and 632 respectively to estimate the first distance and the second distance. The auxiliary node receives the third PDS, and performs step 642 to estimate the third distance and performs step 670 to report the third estimated distance to the first UE 101. The UE 101 then performs step 680 to estimate the direction.

[0102] Apart from Fig.9A In addition, Fig. 9B A signaling diagram including LMF 139 is shown. Fig. 9B, the first UE 101 performs step 601 by sending a request to the LMF 139 to estimate the direction. The RAN 111 performs step 610 to provide the configuration of the first SL-PDS, the second PDS and the third PDS to the first UE 101, the second UE 102 and the first auxiliary node, respectively. The LMF 139 performs steps 621, 631 and 641 to trigger the exchange of the first SL-PDS, the second PDS and the third PDS. The first UE 101 receives the first SL-PDS and the second PDS, and performs steps 623 and 632 respectively to estimate the first distance and the second distance. The first UE 101 then performs step 670 to report the first estimated distance and the second estimated distance to the LMF 139. The auxiliary node receives the third PDS and performs step 642 to estimate the third distance, and performs step 670 to report the estimated third distance to the LMF 139. Then, the LMF 139 performs step 680 to estimate the direction from the first UE 101 to the second UE 102. Finally, the LMF 139 performs step 690 to report the estimated direction to the first UE 101.

[0103] Fig.9A and Fig. 9B 1 and 2 show examples of how a node or UE can perform the steps of method 600. It should be understood that these steps can be distributed differently on multiple nodes, or can be partially or completely performed by other nodes of communication network 100. In addition, although Fig.9A and Fig. 9B A specific order of the steps of method 600 is shown, but the order may be changed according to the configuration of the corresponding nodes, the spatial arrangement and other factors. Fig.9A and Fig. 9B Some steps are omitted, which indicates that not all steps of method 600 need to be performed to estimate the direction from the first UE 101 to the second UE 102. Some steps, such as step 690, may also not be shown because they are performed in the node. Fig.9A In the embodiment, the first UE 101 estimates the direction and may therefore perform step 690 within the node, as discussed above.

[0104] In addition to the above discussion of the drawings, the present invention can be further illustrated by the following embodiments.

[0105] In one example, a method for estimating a direction from a first user equipment UE to a second UE, wherein the first UE and the second UE are capable of connecting to a communication network, the method may include the following steps: obtaining a first estimated distance between the first UE and the second UE based on a first sidelink position determination signal SL-PDS transmitted on a sidelink between the first UE and the second UE of the communication network; obtaining a second estimated distance between the first UE and a first auxiliary node associated with the communication network based on a second position determination signal PDS transmitted between the first UE and the first auxiliary node; obtaining a third estimated distance between the second UE and the first auxiliary node based on a third PDS communicated between the second UE and the first auxiliary node; and estimating the direction from the first UE to the second UE based on the first estimated distance, the second estimated distance, and the third estimated distance.

[0106] In one example, the exemplary method may also include configuring, at at least one of the first UE or the second UE, a SL-PDS configuration for configuring the SL-PDS.

[0107] In one example, configuring the SL-PDS configuration may include transmitting the SL-PDS configuration from an access node or a location control node of the communication network to at least one of the first UE or the second UE.

[0108] In one example, configuring the SL-PDS configuration may include communicating the SL-PDS configuration between the first UE and the second UE using control signaling on a sidelink.

[0109] In one example, the SL-PDS configuration may include at least one of the following: transmission timing of the SL-PDS, time-frequency resources allocated to the SL-PDS by the communication network, transmit power of the SL-PDS, beam configuration of the SL-PDS, sequence design of the SL-PDS, at least one report item for reporting the exchange of the SL-PDS between the first UE and the second UE, the time point at which the first SL-PDS will be sent, or the time interval at which the first SL-PDS will be sent.

[0110] In one example, the step of obtaining the first estimated distance may include triggering an exchange of a first SL-PDS between the second UE and the first UE on a first sidelink communication channel established between the first UE and the second UE on a sidelink of the communication network.

[0111] In one example, the step of obtaining the first estimated distance may include triggering an exchange of a first SL-PDS between the second UE and the first UE using a broadcast transmission of at least one of the first UE or the second UE.

[0112] In one example, the step of obtaining the first estimated distance may include estimating the first estimated distance based on a reception property of a first SL-PDS exchanged between the second UE and the first UE.

[0113] In one example, the reception attribute may include at least one of received signal strength, propagation time, angle of departure, or angle of arrival.

[0114] In one example, the step of obtaining the second estimated distance and the third estimated distance may include triggering an exchange of a second PDS between the first UE and the first assisting node and triggering an exchange of a third PDS between the second UE and the first assisting node.

[0115] In one example, the exchange of a second PDS between a first UE and a first auxiliary node and the exchange of a third PDS between the second UE and the first auxiliary node may be on a sidelink of a communication network, wherein the second PDS and the third PDS may be SL-PDSs, respectively, and wherein the first auxiliary node is a first auxiliary UE.

[0116] In one example, the exchange of the second PDS and the third PDS may be respectively on a second sidelink communication channel established between the first UE and the first auxiliary UE on a sidelink of the communication network and a third sidelink communication channel established on a sidelink between the second UE and the first auxiliary UE.

[0117] In one example, the exchange of the second PDS and the third PDS may use a broadcast transmission on the sidelink.

[0118] In one example, the step of obtaining a second estimated distance and a third estimated distance may include: estimating the second estimated distance based on a reception property of the second PDS exchanged between the auxiliary node and the first UE; and estimating the third estimated distance based on a reception property of the third PDS exchanged between the second UE and the first auxiliary node.

[0119] In one example, the method may also include the following steps: based on a fourth PDS, obtaining a fourth estimated distance between the first UE and a second auxiliary node; and based on a fifth PDS, obtaining a fifth estimated distance between the second UE and the second auxiliary node, wherein estimating the direction from the first UE to the second UE may also be based on the fourth estimated distance and the fifth estimated distance.

[0120] In one example, the direction from the first UE to the second UE can be selectively estimated based on the second estimated distance to the fifth estimated distance according to one or more trigger criteria, and the one or more trigger criteria include at least one of the following: whether line-of-sight communication between the first UE and the second UE is available; the mobility level of the first UE; the mobility level of the second UE; the mobility level of the first auxiliary node; or a predetermined positioning accuracy requirement.

[0121] In one example, the method may also include a step of triggering the exchange of at least one of the first SL-PDS, the second PDS, or the third PDS, wherein the triggering step includes providing a trigger message to at least one of the first UE, the second UE, or the auxiliary node, the trigger message defining an initiator and a receiver of the first SL-PDS or the second PDS and at least one of the third PDS.

[0122] In one example, the step of estimating the corresponding estimated distance may be performed by a receiver of the first SL-PDS or at least one of the second PDS and the third PDS.

[0123] In one example, the triggering step may further include defining a distance estimation method for estimating the corresponding estimated distance.

[0124] In one example, the distance estimation method may be one of one-way ranging or round-trip measurement.

[0125] In one example, the distance estimation method may further define the measurement type, wherein the measurement type is one of a signal strength-based measurement, an angle-based measurement, or a time-based measurement.

[0126] In one example, the measurement type may be one of reference signal received power RSRP, time difference of arrival TDOA, or a time difference between a transmitter and a receiver.

[0127] In one example, the trigger message may also define a configuration of the first SL-PDS or at least one of the second PDS and the third PDS.

[0128] In one example, the triggering step may be performed by one of the first UE, an access node of the communication network, and a location control node of the communication network.

[0129] In one example, the method may further include the step of obtaining a report message indicating at least one of the estimated first distance, the estimated second distance, or the estimated third distance.

[0130] In one example, the report message may include the corresponding estimated distance and at least one report item, wherein the at least one report item is optionally specified by a trigger message defining an initiator and a receiver of the first SL-PDS or a corresponding one of the second PDS and the third PDS.

[0131] In one example, the at least one report item may include at least one of one or more distance estimation parameters for estimating a corresponding estimated distance, a line of sight indication, a reception direction, and a reception location.

[0132] In one example, one or more distance estimation parameters may include reception properties of the first SL-PDS or at least one of the second PDS and the third PDS, received signal strength, arrival time difference, round-trip time, transmitter ID, receiver ID, arrival angle, departure angle, transmitter beam information, transmitter beam ID, receiver beam information, and at least one of the receiver beam ID.

[0133] In one example, the direction from the first UE to the second UE may be estimated based on the azimuth.

[0134] In one example, the azimuth angle may be calculated based on the following equation:

[0135]

[0136] Wherein, θ is the estimated angle, d1 is the first estimated distance, d2 is the second estimated distance, and d3 is the third estimated distance.

[0137] In one example, the direction may be estimated by one of the first UE and the position control node.

[0138] In one example, the method may include the step of selecting a first auxiliary node from a plurality of candidate nodes.

[0139] In one example, the step of selecting the first auxiliary node from the plurality of candidate nodes may depend on a plurality of predetermined distances between the first UE and each of the plurality of candidate nodes.

[0140] In one example, the first auxiliary node may be selected based on a shortest distance among a plurality of predetermined distances.

[0141] In one example, the step of selecting the first auxiliary node from the plurality of candidate nodes may also depend on a plurality of additional predetermined distances between the second UE and each of the plurality of candidate nodes, the plurality of additional predetermined distances being obtained from distance observations different from the plurality of predetermined distances.

[0142] In one example, a plurality of predetermined distances may be predetermined based on cells of a communication network associated with each of the plurality of candidate nodes and the second UE and the first UE.

[0143] The foregoing description has been provided to illustrate estimating a direction from a first UE to a second UE while relying at least in part on direct communication between the first UE and the second UE. It should be understood that this description is by no means intended to limit the scope of the present invention to the precise embodiments discussed throughout the description. On the contrary, those skilled in the art will appreciate that these embodiments may be combined, modified or condensed without departing from the scope of the present invention as defined by the appended claims.

Claims

1. A method for estimating a direction from a first user equipment UE to a second UE, the first UE and the second UE being connectable to a communication network, the method The following steps are involved: Obtaining a first estimated distance between the first UE and the second UE based on a first sidelink position determination signal SL-PDS transmitted on a sidelink between the first UE and the second UE of the communication network; obtaining a second estimated distance between the first UE and a first auxiliary node associated with the communication network based on a second position determination signal PDS transmitted between the first UE and the first auxiliary node; obtaining a third estimated distance between the second UE and the first auxiliary node based on a third PDS transmitted between the second UE and the first auxiliary node; as well as A direction from the first UE to the second UE is estimated based on the first estimated distance, the second estimated distance, and the third distance.

2. The method according to claim 1, in, The method further comprises: At at least one of the first UE or the second UE, a SL-PDS configuration for configuring the SL-PDS is configured.

3. The method according to claim 2, in, The SL-PDS configuration includes at least one of the following: The sending timing of the SL-PDS, time-frequency resources allocated to the SL-PDS by the communication network, The transmission power of the SL-PDS, The beam configuration of the SL-PDS, The sequence design of the SL-PDS, at least one reporting item for reporting the exchange of the SL-PDS between the first UE and the second UE, The time point at which the first SL-PDS is to be sent, or The time interval at which the first SL-PDS will be sent.

4. The method according to any one of the preceding claims, in, The step of obtaining the first estimated distance comprises: An exchange of the first SL-PDS between the second UE and the first UE is triggered on a first sidelink communication channel established between the first UE and the second UE on the sidelink of the communication network.

5. The method according to any one of claims 1 to 4, in, The step of obtaining the first estimated distance comprises: An exchange of the first SL-PDS between the second UE and the first UE is triggered using a broadcast transmission of at least one of the first UE or the second UE.

6. The method according to any one of the preceding claims, in, The step of obtaining the first estimated distance comprises: The first estimated distance is estimated based on a reception property of the first SL-PDS exchanged between the second UE and the first UE.

7. The method according to claim 6, in, The reception attribute includes at least one of received signal strength, propagation time, departure angle, or arrival angle.

8. The method according to any one of the preceding claims, in, The step of obtaining the second estimated distance and the third estimated distance comprises: An exchange of a second PDS between the first UE and the first assisting node is triggered, and an exchange of a third PDS between the second UE and the first assisting node is triggered.

9. The method according to claim 8, in, The exchange of the second PDS between the first UE and the first auxiliary node and the exchange of the third PDS between the second UE and the first auxiliary node are on the sidelink of the communication network, Wherein, the second PDS and the third PDS are SL-PDS respectively, The first auxiliary node is a first auxiliary UE.

10. The method according to claim 9, in, The exchange of the second PDS and the third PDS on a second sidelink communication channel established between the first UE and the first auxiliary UE and on a third sidelink communication channel established between the second UE and the first auxiliary UE on the sidelink of the communication network, respectively; or Broadcast transmission on the sidelink is used.

11. The method according to any one of the preceding claims, in, The step of obtaining the second estimated distance and the third estimated distance comprises: estimating the second estimated distance based on a reception property of the second PDS exchanged between an assisting node and the first UE; and The third estimated distance is estimated based on a reception property of the third PDS exchanged between the second UE and the first assisting node.

12. The method according to any one of the preceding claims, further comprising: The following steps are involved: Obtaining a fourth estimated distance between the first UE and the second auxiliary node based on a fourth PDS; as well as obtaining, based on a fifth PDS, a fifth estimated distance between the second UE and the second auxiliary node, The estimating the direction from the first UE to the second UE is also based on the fourth estimated distance and the fifth estimated distance.

13. The method according to claim 12, in, The direction from the first UE to the second UE is selectively estimated based on the second estimated distance to the fifth estimated distance according to one or more trigger criteria, and the one or more trigger criteria include at least one of the following: whether line-of-sight communication between the first UE and the second UE is available; the mobility level of the first UE; the mobility level of the second UE; the mobility level of the first auxiliary node; or a predetermined positioning accuracy requirement.

14. The method according to any one of the preceding claims, further comprising the step of triggering the exchange of at least one of the first SL-PDS, the second PDS or the third PDS, in, The triggering step includes providing a trigger message to at least one of the first UE, the second UE or an auxiliary node, the trigger message defining an initiator and a receiver of the first SL-PDS or the at least one of the second PDS and the third PDS.

15. The method according to claim 14, in, The step of estimating the corresponding estimated distance is performed by a receiver of the first SL-PDS or at least one of the second PDS and the third PDS.

16. The method according to claim 14 or 15, in, The triggering step further comprises defining a distance estimation method to be used to estimate said corresponding estimated distance.

17. The method according to claim 16, in, The distance estimation method is one of one-way ranging or round-trip measurement.

18. The method according to claim 16 or 17, in, The distance estimation method further defines a measurement type, wherein the measurement type is one of a signal strength based type, an angle based type, or a time based type.

19. The method according to any one of claims 14 to 18, in, The trigger message also defines a configuration of the first SL-PDS or the at least one of the second PDS and the third PDS.

20. The method according to any one of claims 14 to 19, in, The triggering step is performed by one of the first UE, an access node of the communication network, and a location control node of the communication network.

21. The method of any preceding claim, further comprising the step of obtaining a report message indicating at least one of the estimated first distance, the estimated second distance or the estimated third distance.

22. The method according to claim 21, in, The report message includes a corresponding estimated distance and at least one report item, and the at least one report item is optionally specified by a trigger message defining an initiator and a receiver of a corresponding one of the first SL-PDS or the second PDS and the third PDS.

23. The method according to claim 22, in, The at least one report item includes one or more distance estimation parameters for estimating the corresponding estimated distance, a line of sight indication, a receiving direction, and at least one of the position of the receiver, and wherein the one or more distance estimation parameters include reception properties of the first SL-PDS or at least one of the second PDS and the third PDS, received signal strength, arrival time difference, round-trip time, transmitter ID, receiver ID, arrival angle, departure angle, transmitter beam information, transmitter beam ID, receiver beam information, and at least one of the receiver beam ID.

24. A method according to any one of the preceding claims, in, The direction from the first UE to the second UE is estimated based on an azimuth angle, wherein the azimuth angle is calculated based on the following equation: where θ is the estimated angle, d 1 is the first estimated distance, d 2 is the second estimated distance, and d 3 is the third estimated distance.

25. A method according to any preceding claim, further comprising the step of selecting the first auxiliary node from a plurality of candidate nodes.

26. The method according to claim 25, in, The step of selecting the first auxiliary node from a plurality of candidate nodes depends on a plurality of predetermined distances between the first UE and respective candidate nodes of the plurality of candidate nodes.

27. The method according to claim 26, in, The first auxiliary node is selected based on a shortest distance among the plurality of predetermined distances.

28. The method according to claim 26 or 27, in, The step of selecting the first auxiliary node from a plurality of candidate nodes is further dependent on a plurality of further predetermined distances between the second UE and respective candidate nodes of the plurality of candidate nodes, the plurality of further predetermined distances being obtained from distance observations different from the plurality of predetermined distances.

29. The method according to any one of claims 26 to 28, in, The plurality of predetermined distances are predetermined based on cells of the communication network associated with respective candidate nodes of the plurality of candidate nodes and the second UE and the first UE.

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