Determining location of target user equipment relative to location of anchor user equipment
By establishing a side-link communication between the target UE and the anchor UE, and using SLPP and positioning reference signals combined with local sensor information, the relative position of the target UE is calculated, solving the positioning problem in urban canyons where GNSS is lacking, and achieving fast and reliable position determination.
Patent Information
- Application Number
- CN202480050116.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-07-31
- Filing Date
- 2024-07-30
- Publication Date
- 2026-03-03
AI Technical Summary
In the absence of a global navigation satellite system, especially in urban canyons, existing technologies struggle to quickly and reliably determine the location of mobile devices.
By establishing sidelink communication between the target user equipment (UE) and the anchor UE, the absolute position of the anchor UE is requested using the 3GPP Sidelink Positioning Protocol (SLPP). Combined with positioning reference signals and local sensor information, the relative position of the target UE is calculated using filter techniques such as extended Kalman filters, and the positioning filter is updated to improve accuracy.
It enables the rapid and reliable determination of the relative position of the target UE with respect to the anchor UE in the absence of GNSS support, thereby improving positioning accuracy and robustness.
Smart Images
Figure CN121605722A_ABST
Abstract
Description
Background Technology
[0001] A wireless communication device, also known as a mobile device or user equipment (UE), communicates with a base station of a wireless network or directly with another UE. A UE can be a portable cellular device or a vehicle such as a car or electric bicycle. A UE can also be a terminal supporting Secure User Plane Positioning (SUPL). When the UE is a vehicle, device-to-device (D2D) communication can be referred to as vehicle-to-vehicle (V2V) communication. Other vehicle-based UE communications include vehicle-to-infrastructure (V2I), vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P).
[0002] For some applications, even in the absence of support from Global Navigation Satellite Systems (GNSS) such as GPS, Galileo, or GLONASS, obtaining the UE's location via wireless communication systems is crucial. This could be applicable to UEs located in urban canyons, for example. Therefore, a further system is needed for reliably and quickly locating mobile devices.
[0003] Sidelink is one of the core technologies of 5G systems, enabling direct communication between two UEs without accessing the wireless network. Through the sidelink interface, the 3GPP Sidelink Positioning Protocol (SLPP) allows for the exchange of location data between UEs. Summary of the Invention
[0004] A first aspect of this disclosure relates to a method for determining the location of a first user equipment (UE) relative to the location of a second UE.
[0005] The methods disclosed herein include: - Establish a positioning mechanism at a higher communication layer for the target UE. - The target UE initiates sidelink communication via the sidelink positioning protocol through the sidelink interface of the wireless network between the target UE and the anchor UE. - The target UE requests the absolute position of the anchor UE from the anchor UE via the side link interface. - The target UE receives a positioning reference signal from the anchor UE via a side link interface. The positioning reference signal includes the absolute position of the anchor UE, preferably along with uncertainty information regarding the absolute position. - The distance to the anchor UE is evaluated based on the signal running time of the target UE using the positioning reference signal. - The target UE calculates its position relative to the anchor UE based on an estimate of the measurement error along with the evaluation. - The target UE requests the absolute position of the target UE from a higher layer. - The relative position of the target UE with respect to the anchor UE is determined by using the absolute position of the target UE and the absolute position of the anchor UE, preferably together with an estimate of the measurement error. - The target UE updates the positioning mechanism's input using the calculated relative position and the determined relative position.
[0006] The second aspect of this disclosure relates to a user equipment adapted to communicate via a sidelink positioning protocol through a sidelink interface of a wireless network, the user equipment including a positioning mechanism in a higher communication layer and adapted to perform the method according to the first aspect (or embodiments thereof).
[0007] A third aspect of this disclosure relates to a computer system adapted to perform the method according to the first aspect (or embodiments thereof).
[0008] The fourth aspect of this disclosure relates to a computer program that includes instructions that, when executed by a computer, cause the computer to perform the method according to the first aspect (or an embodiment thereof).
[0009] The fifth aspect of this disclosure relates to a computer-readable medium or signal that stores and / or contains a computer program according to the third aspect (or its embodiments).
[0010] The technologies in the first through fifth aspects can have favorable technical effects.
[0011] First, the technology disclosed herein is proposed for a target UE that does not have precise positioning (e.g., GNSS in an urban canyon) but is able to use 3GPP side link positioning (SLPP) to request location information from an anchor UE. A better estimate of the actual relative position of the target UE is proposed, using two relative position measurements from different channels.
[0012] Second, the technology disclosed herein provides a higher-level or L3 mechanism (such as filters in the L3 function of a UE) that allows the sidelink position management function (SLMF) to use local sensors (e.g., velocity sensors, GNSS (if available)) along with information fragments obtained from the SLPP (relative position to the anchor UE, absolute position of the anchor UE). The filter is updated to improve the estimation of the relative position between the two UEs. Therefore, the filter combines different measurements.
[0013] Third, the technology disclosed herein allows for the generation of accurate location data from measurements with low accuracy by incorporating further information from the UE (such as, for example, GNSS location).
[0014] Fourth, the technology disclosed herein allows for the efficient use of information provided in the side link location management function (SLMF) and efficient positioning of the SLMF.
[0015] Some terms are used in this specification as follows: The term "OSI layer" refers to one of the seven layers of the OSI model. The Open Systems Interconnection (OSI) model is a conceptual model from the International Organization for Standardization (ISO). In the OSI model, communication between computing systems is divided into seven different abstract layers: Physical Layer, Data Link Layer, Network Layer, Transport Layer, Session Layer, Presentation Layer, and Application Layer, with the Physical Layer being the lowest layer.
[0016] The terms "location filter" or "L3 (layer 3) filter" can refer to linear filters, extended Kalman filters (EKF), particle filters (sequence Monte Carlo method), etc., arranged in the third (network) layer according to the OSI model. Therefore, the L3 filter operates independently of L1 and L2, allowing L1 / L2 values, for example, obtained from SLPP, to be input into the L3 filter. The filter is adapted for measurement switching from higher to lower layers and vice versa, i.e., inter-layer signaling. The filter has coefficients and is input in the time domain.
[0017] The filter can be implemented as an FIR filter as shown below.
[0018] F_n = (1-a).F_{n-1}+a.M_n In this example, possible structures for an FIR filter include: M_n is the latest measurement received from a lower layer in state n (where n is the current time state). F_n is the updated measurement result in state n. F_{n-1} is the filter measurement result under the previous state n-1. a is the filter coefficient.
[0019] Examples of filter measurements could be: Channel quality and Received Strength Signal Indication (RSSI) measurements, where the L3 filter can average RSSI values based on individual RSSI measurements.
[0020] Localization, where filters update and enhance localization based on existing measurements from multiple sources.
[0021] The filter can be implemented as a continuous-time extended Kalman filter as shown below.
[0022] In this model, the motion of the UE can be obtained as the model (x'(t) = ...) and its corresponding error w(t), and the measurement (relative / absolute) can be obtained as z(t) and the corresponding error v(t). The prediction / update steps depend on the filter, but the ultimate goal is to improve the estimation of the relative position between the two UEs.
[0023] Q and R are covariance matrices, and u is the control vector. P is the covariance estimate. K is the Kalman gain. F and H are the state transition Jacobian matrix and the observation Jacobian matrix, respectively. Attached Figure Description
[0024] Figure 1 It is a flowchart illustrating a method for determining the position of a first user equipment relative to the position of a second user equipment, as described in the first aspect.
[0025] Figure 2 The possible topologies of this technology are illustrated schematically.
[0026] Figure 3 The schematic illustration shows possible communication topologies of this technology.
[0027] Figure 4 The schematic illustration shows possible communication topologies of this technology. Detailed Implementation
[0028] Figure 1 This is a flowchart of method 10 for determining the position of a target user equipment UE relative to the position of an anchor UE, based on the first aspect. This method allows for precise relative positioning using the relative position of the anchor point or UE and local sensors, aided by filtering. This method can be performed partially or entirely by the target UE.
[0029] First, the target UE performs the establishment of a positioning mechanism (such as a positioning filter) in a higher communication layer. The positioning filter can be established at Layer 3 of the OSI model. The filter, or one or more of its coefficients, can use initialization values from a wireless network (such as a 5G network). The filter includes computational capabilities and inter-layer signaling capabilities for combining different measurements. Therefore, the positioning or L3 filter operates independently of L1 and L2, allowing L1 / L2 values, for example, obtained from SLPP, to be input into the L3 filter.
[0030] Next, the target UE initiates step 12, which involves initiating sidelink communication via the sidelink positioning protocol through the sidelink interface of the wireless network between the target UE and the anchor UE.
[0031] Subsequently, the target UE executes request 13, thereby requesting the absolute position of the anchor UE from the anchor UE via the side link interface. The 3GPP Side Link Positioning Protocol (SLPP) allows UEs to exchange location data via the side link interface.
[0032] The target UE performs reception 14, thereby receiving a positioning reference signal from the anchor UE via a side link interface. The positioning reference signal includes the absolute position of the anchor UE along with uncertainty information regarding that absolute position. The uncertainty information may include an uncertainty ellipse surrounding the position of the anchor UE. Furthermore, the position of the anchor UE may be an ellipsoidal point.
[0033] Subsequently, evaluation 15 is performed at the target UE, where the distance to the anchor UE is evaluated based on the signal run time of the positioning reference signal. Further, the evaluation can be based on the angle of arrival of the positioning reference signal.
[0034] Next, calculation 16 is performed on the target UE, where its position relative to the anchor UE is calculated based on the evaluation along with an estimate of the measurement error. The position of the target UE can be calculated in polar coordinates. The measurement error can be obtained through error propagation calculations, stochastic models, or statistical parameters of the error distribution.
[0035] Subsequently, the target UE executes request 17, thereby requesting its absolute position from a higher layer, such as its GNSS position coordinates.
[0036] The target UE performs the determination 18, thereby using the absolute position of the target UE and the absolute position of the anchor UE to determine the relative position of the target UE with respect to the anchor UE, along with an estimate of the measurement error. The measurement error can be obtained through error propagation calculations, stochastic models, or statistical parameters of the error distribution.
[0037] Subsequently, the target UE performs calculation 19, thereby calculating the error of the calculated relative position and / or the error of the determined relative position based on the calculation uncertainty information and / or measurement error, respectively. In other words, the target UE performs utilization 19, thereby utilizing the uncertainty information and / or measurement error for the calculation of the calculated relative position and the calculation of the determined relative position, respectively. The uncertainty information and / or measurement error may also be utilized in the corresponding steps described above.
[0038] Finally, update 20 is performed on the target UE, thereby updating the input of the positioning filter with the calculated relative position and the determined relative position. The update depends on the filter used, which may be an EKF. Here, the input of the positioning mechanism is further updated with the calculation error of the calculated relative position and / or the calculation error of the determined relative position.
[0039] The above steps can be processed iteratively (i.e., in a loop). Intermediate steps 12 to 19 can be considered as data preparation for the filter updates performed in steps 11 and 20. In step 11, an initial setup can be performed. After step 19, the filter is subsequently updated or reinitialized according to steps 20 and 11.
[0040] The filter output is, optionally, a more accurate relative position of the target UE with respect to the anchor UE in polar coordinates. This relative position becomes increasingly accurate with each iteration of the filter.
[0041] Additionally, if the angle of arrival (AoA) resolution is too poor or unavailable, the positioning filter can compensate for the missing or poor information using the absolute position coordinates transmitted by the SLMF (of the anchor UE) and higher layers of the target UE. Furthermore, when the target UE lacks angle resolution capability (e.g., due to its implemented antenna / antenna array), the target UE's SLMF (or the network, if the network is configuring SLMF) configures the filter to overcome the AoA calculation. This can be achieved, for example, by changing the filter coefficients of the AoA value.
[0042] Figure 2 The schematic illustration shows a possible topology of the present technology implemented in system 30. System 30 may be a computing system according to the third aspect, adapted to perform the methods described above.
[0043] System 30 includes or is a part of wireless network 31. Wireless network 31 may be a wireless communication network according to one of the 3GPP standards (such as, for example, 5G). Wireless network 31 includes one or more relay (Via) stations not depicted for ease of understanding. Wireless network 31 may include gNBs and ng-eNBs.
[0044] System 30 further includes an anchor UE 40 and a target UE 50. Anchor UE 40 may be a vehicle, such as a car. Target UE 50 may be a further vehicle, such as, for example, an electric bicycle. Anchor UE 40 includes a sidelink location management function 42 (SLMF) for managing 3GPP sidelink positioning (SLP). Anchor UE 40 further includes an application layer or application 44. Target UE 50 includes a sidelink location management function 52 for managing 3GPP sidelink positioning; and an application layer or application 54. Target UE 50 and anchor UE 40 can communicate via the sidelink interface 32 of wireless network 31, via the sidelink positioning protocol (SLPP). Target UE 50 and anchor UE 40 can request and exchange their respective locations and further location information via the sidelink interface 32.
[0045] The target UE 50 can communicate with the wireless network 31 via the NR-Uu interface 33. The NR-Uu interface 33 connects the UE 50 to the gNB of the wireless network 31 via the air interface. For a target UE accessing the NG-RAN using NR, the NR-Uu interface 33 is used as one of several transport links for the LTE positioning protocol. Similarly, the anchor UE 40 communicates with the wireless network 31 via the NR-Uu link or interface 34. Furthermore, the anchor UE 40 can communicate with the wireless network 31 via the LTE-Uu interface 35. The LTE-Uu interface connects the UE to the eNode B of the wireless network 31 via the air interface and is used as one of several transport links for the LTE positioning protocol.
[0046] Anchor UE 40 has a further (S)LPP connection 36 with the gNB of wireless network 31. Connection 36 implements 3GPP side link positioning protocol (SLPP) or LTE positioning protocol (LPP).
[0047] Figure 3 The possible communications of a possible topology of this technology are illustrated schematically. Communication between anchor UE 40 (e.g., a car) and target UE 50 (e.g., an electric bicycle) is described. For target UE 50, the communication is described for the side link location management function 52 of target UE 50 and one or more applications 54. The communication includes reporting to lower-level non-RAT measurements.
[0048] Communication between anchor UE 40 and sidelink location management function 52 occurs at Layers 1 and 2 of the OSI model. Sidelink location management function 52 and its location filter are located at or organized at Layer 3. Communication between application 54 and sidelink location management function 52 occurs at higher layers, i.e., above Layer 3. Computation is performed within sidelink location management function 52 in the 3GPP stack.
[0049] Initially, application 54 requests the relative position of target UE 50 with respect to anchor UE 40 from the sidelink location management function 52. Next, the filter is initialized in management function 52. Within the coverage of the wireless network, sidelink location management function 52 can be inherited from the network. Subsequently, the filter configuration, requested possible information collection, and data collection strategies can be directly configured by the network. If target UE 50 is outside network coverage, sidelink location management function 52 can be initiated through pre-configuration, in which values are configured. These values are either configured offline from the time the UE is connected or configured via software update. Such configuration should include possible coefficient configurations for the filter.
[0050] Subsequently, the sidelink location management function 52 requests SLPP signaling from the anchor UE 40. The anchor UE 40 provides its absolute position via SLPP signaling. Thus, the sidelink location management function 52 is provided with the anchor UE's local coordinate information, such as, for example, GNSS coordinates or ellipsoidal points. This SL positioning report further includes possible errors or uncertainties, such as, for example, ellipsoidal points with uncertain ellipses.
[0051] The sidelink location management function 52 extracts the relative position of the target UE 50 with respect to the anchor UE 40 from the SL location report.
[0052] Next, the sidelink location management function 52 requests the location of the target UE 50 from the application 54. The location of the target UE 50 is provided by the application 54 to the sidelink location management function 52.
[0053] Subsequently, the sidelink location management function 52 calculates the relative position of the anchor UE 40 based on the absolute position of the target UE 50 received from the target UE 50 using the SL location report and based on the absolute position of the target UE 50 received from the application 54.
[0054] Next, the sidelink location management function 52 updates the filter using the relative position measured or extracted based on the SL location report and the relative position calculated based on the position provided by the application 54. One or more coefficients of the filter are updated to improve the accuracy of the filter.
[0055] The filter outputs an estimate of the relative position of the target UE 50 with respect to the anchor UE 40, or the next iteration, to the application 54. Actions performed after filter initialization are executed cyclically, iterating the relative position of the target UE 50 with respect to the anchor UE 40 to the precise position. Iteration is achieved by the filter, or more precisely, by updating or adapting the filter coefficients.
[0056] Figure 4 The possible communications of a possible topology of this technology are illustrated schematically. Communication between anchor UE 40 (e.g., a car) and target UE 50 (e.g., an electric bicycle) is described. For target UE 50, the communication is described for the sidelink location management function 52 of target UE 50 and one or more applications 54. The communication covers reporting to higher layers (including measurement reports).
[0057] and Figure 3In contrast, the sidelink location management function 52 is an entity that has an interface with SL measurements and enables cross-layer API triggering and collection of corresponding requests / measurements. Calculations are performed at a higher layer (e.g., the application layer). Location filters are located at or organized within these or this higher layer. Measurement reports (i.e., the relative position of the target UE 50 to the anchor UE 40, the absolute position of the anchor UE 40, and their measurement errors) are requested by application 54 and reported to application 54 via appropriate inter-layer signaling.
[0058] Initially, the filter is initialized in application 54. Within the coverage of the wireless network, the filter configuration, requested possible information gathering, and data collection strategies can be configured directly by the network. If the target UE 50 is outside network coverage, these values are either configured offline from the time the UE is connected or configured via a software update. Such configuration should include possible coefficient configurations for the filter.
[0059] Next, application 54 requests measurements from the side link location management function 52. The requested measurements include the relative position of the target UE 50 to the anchor UE 40, the absolute position of the anchor UE 40, and their measurement errors.
[0060] In response, the sidelink location management function 52 requests SLPP signaling from the anchor UE 40. The anchor UE 40 provides its absolute position via the SLPP signaling. Thus, the sidelink location management function 52 is provided with local coordinate information of the anchor UE, such as, for example, GNSS coordinates or ellipsoidal points. The SL positioning report further includes possible errors or uncertainties, such as, for example, ellipsoidal points with uncertain ellipses.
[0061] The sidelink location management function 52 extracts the relative position of the target UE 50 with respect to the anchor UE 40 from the SL location report.
[0062] Subsequently, the sidelink location management function 52 provides the requested measurements to the application 54. The requested measurements include the relative position of the target UE 50 to the anchor UE 40, the absolute position of the anchor UE 40, and their measurement errors.
[0063] Next, application 54 calculates the relative position of the anchor UE 40 based on the absolute position of the target UE 50 received from the target UE 50 using the SL positioning report and based on the absolute position of the target UE 50 that is available in application 54 or to application 54.
[0064] Next, application 54 updates the filter using the relative position measured or extracted based on the SL positioning report and the relative position calculated based on the position known in application 54. One or more coefficients of the filter are updated to improve the accuracy of the filter.
[0065] The filter provides an estimate of the relative position of the target UE 50 with respect to the anchor UE 40, or the next iteration, to the application 54. Actions performed after filter initialization are executed cyclically, iterating the relative position of the target UE 50 with respect to the anchor UE 40 to the precise position. Iteration is achieved by the filter, or more precisely, by updating or adapting the filter coefficients.
Claims
1. A method for determining the location of a target user equipment (UE) (50) relative to the location of an anchor UE (40), the method (10) comprising: -A positioning mechanism (11) is established in a higher communication layer in the target UE (50). - The target UE (50) initiates (12) sidelink communication via the sidelink positioning protocol through the sidelink interface (32) of the wireless network (31) between the target UE (50) and the anchor UE (40). -The target UE (50) requests (13) the absolute position of the anchor UE (40) from the anchor UE (40) via the side link interface (32). - The target UE (50) receives (14) a positioning reference signal via the side link interface (32) and from the anchor UE (40), the positioning reference signal including the absolute position of the anchor UE (40), preferably together with uncertainty information about the absolute position. -The distance from the target UE (50) to the anchor UE (40) is evaluated (15) based on the signal running time of the positioning reference signal. -The target UE (50) calculates (16) its position relative to the anchor UE (40) based on the assessment along with an estimate of the measurement error. -The target UE (50) requests (17) the absolute position of the target UE (50) from a higher layer. - The relative position of the target UE (50) with respect to the anchor UE (40) is determined by the absolute position of the target UE (50) and the absolute position of the anchor UE (40), preferably together with an estimate of the measurement error. - The target UE (50) updates the input of the positioning mechanism (20) with the calculated relative position and the determined relative position.
2. The method according to claim 1, further comprising: In the target UE (50), based on the calculated uncertainty information and / or measurement error, the error of the calculated relative position and / or the error of the determined relative position are calculated (19), respectively, wherein the input of the positioning mechanism is further updated with the calculation error of the calculated relative position and / or the calculation error of the determined relative position.
3. The method according to claim 1 or 2, wherein the positioning mechanism is a positioning filter.
4. The method of claim 3, wherein the localization filter is established in the third layer of the OSI (Open Systems Interconnection) layer.
5. The method according to claim 3 or 4, wherein establishing the positioning filter includes receiving at least one filter coefficient and / or at least one filter input of the positioning filter from the wireless network (31).
6. The method according to any one of claims 1 to 5, wherein the uncertainty information includes an uncertainty ellipse about the position of the anchor point UE (40).
7. The method according to any one of claims 1 to 6, wherein the evaluation (15) of the distance to the anchor point UE (40) is further based on the angle of arrival of the positioning reference signal.
8. The method according to any one of claims 1 to 7, wherein the method steps are performed in the application layer of the target UE (50), wherein the application layer communicates with the side link location management function (SLMF) (52) via inter-layer signaling.
9. The method according to any one of claims 1 to 7, wherein the method steps are performed in the SLMF in the stack of the wireless network (31).
10. A user equipment adapted to communicate via a sidelink positioning protocol through a sidelink interface (32) of a wireless network (31), the user equipment including a positioning mechanism in a higher communication layer and adapted to perform the method according to any one of claims 1 to 9.
11. A computing system (30) adapted to perform the method according to any one of claims 1 to 9.
12. A computer program comprising instructions that, when executed by a computer, cause the computer to perform the method according to any one of claims 1 to 9.
13. A computer-readable medium or signal that stores and / or contains a computer program according to claim 12.