Multi-path mitigation in rangefinding and tracking objects using reduced attenuation RF technology

• US 9,699,607 B2
• Filed: 12/12/2013
• Issued: 07/04/2017
• Est. Priority Date: 12/15/2005
• Status: Active Grant

• Current Assignee: Qualcomm Technologies Incorporated (Qualcomm, Inc.)
• Original Assignee: Polte Corporation
• Inventors: Markhovsky, Felix, Prevatt, Truman
• Primary Examiner(s): MCNALLY, KERRI L
• Application Number:
  US14/105,098
• Publication Number:
  US 20160366554A1
• Time in Patent Office: 1,300 Days
• Field of Search: 3405721
• CPC Class Codes: G01S 3/46 using antennas spaced apart and measuring phase or time difference between signals therefrom, i.e. path-difference systems
• CPC Class Codes: G01S 5/0218 Multipath in signal reception
• CPC Class Codes: G01S 5/0226 Transmitters
• CPC Class Codes: G01S 5/0273 using multipath or indirect path propagation signals in position determination
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 4/026 using orientation information, e.g. compass
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Methods for determining a LOB of one or more user equipment (UE) in a wireless system employing Time Difference of Arrival (TDOA) is described. TDOA techniques are based on estimating the difference in the arrival times of reference signals from multiple receivers or from multiple emitters to a receiver. A particular value of the time difference estimate defines a hyperbola between the two receivers on which the handset may exist. When the distance between the receiving antennas is small relative to the distance of the emitter source (the handset) being located, then the TDOA is equivalent to the angle between the baseline of the sensors (receivers antennas) and the incident RF energy from the emitter. If the angle between the baseline and true North is known, then the line of bearing (LOB) and/or angle of arrival (AoA), can be utilized to determine the location of the UE.

Claims

1. A method for determining a location of a user equipment (UE) in a wireless system, the method comprising:

determining at the UE specific reference signals from two or more nodes communicated within the wireless system and network parameters for the wireless system and the UE;

receiving at the UE timing offsets associated with the specific reference signals; and

utilizing at the UE the specific reference signals, the timing offsets, and the network parameters to calculate a location of the UE without requiring synchronization between the two or more nodes.

2. The method of claim 1, wherein the wireless system includes one or more nodes and one or more sectors per node, and wherein the network parameters include network node location coordinates, coordinates of the one or more sectors, a number of sectors per node, an azimuth and an elevation of a sector'"'"'s composite receive directionality, including sectors IDs.

3. The method of claim 1, wherein the wireless system includes one or more nodes, one or more antennas per node and one or more sectors per node, and wherein the network parameters include network node location coordinates, coordinates of the one or more sectors, a number of antennas per node;

an azimuth and an elevation of each antenna'"'"'s receive directionality, each antenna'"'"'s location, each node'"'"'s physical antennas to Multiple Input Multiple Output (MIMO) mapping for serving nodes and neighboring nodes, each nodes physical antennas to antenna port mapping for serving nodes and neighboring nodes, and a mapping of each antenna among the one or more antennas to each sector among the one or more sectors.

4. The method of claim 1, wherein the wireless system includes one or more nodes and one or more sectors per node, and wherein received signals from all sectors of each serving node and each neighboring node are sent to a locate server unit.

5. The method of claim 1, wherein the specific reference signals are uplink reference signals, including sounding reference signals (SRS), reference signals for MIMO, or a combination of SRS and reference signals for MIMO.

6. The method of claim 1, wherein the wireless system includes one or more nodes and one or more sectors per node, and wherein SRS schedules and Timing Advance (TA) measurements for the UE are provided to a locate server unit (LSU) by each serving sector at each node.

7. The method of claim 1, wherein the wireless system includes one or more nodes and each of the one or more nodes includes at least one sector, wherein a sector of each node is configured to communicate with a locate server unit (LSU), and further comprising utilizing at the LSU or a combination of the one or more nodes and the LSU the specific reference signals, the timing offsets, and the network parameters to calculate a location of the UE.

8. The method of claim 1, wherein the wireless system includes one or more nodes and each of the one or more nodes includes at least one sector, wherein a sector of each node is configured to communicate with a locate server unit (LSU), and further comprising utilizing at the UE and the LSU, the one or more nodes, or a combination thereof the specific reference signals, the timing offsets, and the network parameters to calculate a location of the UE.

9. The method of claim 8, wherein the UE are configured to communicate with the LSU.

10. The method of claim 9, wherein the UE, the LSU, the one or more nodes, or a combination thereof are configured to support multipath mitigation and reference signals processing to calculate the location of each UE.

11. The method of claim 1, wherein the wireless system is configured to include functionality of a Locate Server Unit (LSU) in a network Secure User Plane Location (SUPL) server, a Evolved Serving Mobile Location Center (E-SMLC) server, a LCS (LoCation Services) system, or a combination thereof.

12. The method of claim 1, wherein the wireless system includes a Locate Server Unit (LSU) and one or more nodes, and wherein the LSU is configured to interface the one or more nodes and network infrastructure of the wireless system.

13. The method of claim 1, wherein the step of utilizing includes utilizing one or more line of bearing (LOB).

14. The method of claim 13, wherein the one or more LOB are obtained from time difference of arrival results from two or more sectors formed by one or more antennas from one or more nodes of the wireless system, one or more locations where the one or more antennas are co-located, one or more locations of a combination of the two or more sectors, one or more locations of the one or more antennas from one or more locations, and combinations thereof.

15. The method of claim 1, wherein the wireless system includes one or more nodes with one or more sectors each formed by one or more antennas, wherein the step of utilizing further includes utilizing a triangulation or three or more line of bearing (LOB) from the one or more nodes, one or more locations where multiples of the one or more antennas are co-located, or a combination of one or more LOB from each of the one or more nodes and the one or more locations.

16. The method of claim 1, wherein the wireless system includes one or more nodes, and wherein the step of utilizing further includes utilizing a combination of a distance measurement between the UE and a single node and one or more line of bearing (LOB) from the single node.

17. The method of claim 1, wherein the wireless system includes one or more nodes, and wherein the step of utilizing further includes utilizing a combination of a distance measurement between the UE and a single node and one or more line of bearing (LOB) from the single node and one or more neighboring nodes to the UE, and one or more locations where multiple antennas are co-located.

18. The method of claim 1, wherein the wireless system includes one or more nodes with one or more sectors each formed by one or more antennas, and wherein the step of utilizing further includes utilizing a multilateration between the one or more sectors, one or more line of bearing (LOB) from one or more nodes or from one or more locations, or a combination of multilateration between the one or more sectors and one or more LOB from one or more nodes or one or more locations.

19. The method of claim 1, wherein the wireless system includes one or more nodes with one or more sectors each formed by one or more antennas, and wherein the step of utilizing further includes utilizing a combination of a distance measurement between the UE and a node among the one or more nodes, or one or more nodes and one or more locations where multiple antennas are co-located and a line of bearing (LOB) from one or more nodes or from one or more locations.

20. The method of claim 1, wherein the step of utilizing further includes utilizing a time difference of arrival to determine one or more line of bearing of the UE.

21. The method of claim 1, wherein the one or more UE are configured to communicate with Locate Server Unit (LSU), a Secure User Plane Location (SUPL) server, a Evolved Serving Mobile Location Center (E-SMLC) server, a LCS (LoCation Services) system or a combination thereof.

22. The method of claim 1, wherein the specific reference signals are downlink reference signals including Cells-Specific Reference Signals (CRS), Position Reference Signals (PRS), reference signals for MIMO, or a combination of CRS, PRS or reference signals for MIMO.

23. The method of claim 22, wherein the wireless system includes one or more nodes and one or more serving sectors per node, and wherein Timing Advance (TA) measurements for each served UE among the UE are provided to a LSU, a SUPL server, a E-SMLC server, a LCS (LoCation Services) system, or a combination thereof by each serving sector among the one or more serving sectors and each node among the one or more nodes.

24. The method of claim 22, wherein PRS schedule measurements are provided to a LSU by the UE, each node among the one or more nodes, or by each serving sector among the one or more serving sectors.

25. The method of claim 22, wherein measurements corresponding to the specific reference signals are provided by each UE among the UE, to a locate server unite (LSU), a SUPL server, a E-SMLC server, a LoCation Services (LCS) system or a combination of the LSU, the SUPL server, the E-SMLC server and the LCS system.

26. A method for determining a location of a user equipment (UE) in a wireless system with one or more sectors each formed by one or more antennas, the method comprising:

determining arrival times at the UE of reference signals from two or more antennas from different sectors of a serving cell tower;

determining a difference in the arrival times to determine an angle between a baseline of the antennas or sectors and incident energy from the UE; and

using the angle to determine the location of the UE.

27. The method of claim 26, wherein one sector among the different sectors is a serving sector and one sector among the different sectors is not a serving sector.

28. The method of claim 26, wherein a distance between the two or more antennas or sectors is small relative to a distance to the UE from the two or more antennas or sectors.

29. A method for determining a location of a user equipment (UE) in a wireless system with one or more sectors each formed by one or more antennas, the method comprising:

determining arrival times from the UE of reference signals at two or more antennas from different sectors of a serving cell tower;

determining a difference in the arrival times to determine an angle between a baseline of the antennas or sectors and incident energy from UE to the two or more antennas or sectors; and

using the angle to determine the location of the UE.

30. The method of claim 29, wherein one sector among the different sectors is a serving sector and one sector among the different sectors is not a serving sector.

31. The method of claim 29, wherein a distance between the two or more antennas or sectors is small relative to a distance to the UE from the two or more antennas.