Angle of arrival (AOA) positioning method and system for positional finding and tracking objects using reduced attenuation RF technology

• US 9,813,867 B2
• Filed: 10/07/2016
• Issued: 11/07/2017
• Est. Priority Date: 12/15/2005
• Status: Active Grant

• Current Assignee: Qualcomm Technologies Incorporated (Qualcomm, Inc.)
• Original Assignee: Polte Corporation
• Inventors: Prevatt, Truman
• Primary Examiner(s): Osifade, Idowu O
• Application Number:
  US15/289,033
• Publication Number:
  US 20170026798A1
• Time in Patent Office: 396 Days
• Field of Search: None
• CPC Class Codes: G01S 13/222 using random or pseudorandom pulse repetition frequency
• CPC Class Codes: G01S 13/24 using frequency agility of carrier wave
• CPC Class Codes: G01S 13/767 Responders; Transponders teaching or practice apparatus for gun-aiming or gun-laying using reflecting targets or active targets F41G3/26
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 2013/466 by Trilateration, i.e. two antennas or two sensors determine separately the distance to a target, whereby with the knowledge of the baseline length, i.e. the distance between the antennas or sensors, the position data of the target is determined
• CPC Class Codes: G01S 2013/468 by Triangulation, i.e. two antennas or two sensors determine separately the bearing, direction or angle to a target, whereby with the knowledge of the baseline length, the position data of the target is determined
• CPC Class Codes: G01S 3/74 Multi-channel systems specially adapted for direction-finding, i.e. having a single antenna system capable of giving simultaneous indications of the directions of different signals systems in which the directions of different signals are determined sequentially and displayed simultaneously G01S3/04, G01S3/14
• CPC Class Codes: G01S 5/0205 Details
• CPC Class Codes: G01S 5/0218 Multipath in signal reception
• CPC Class Codes: G01S 5/02521 using a radio-map
• 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: H01Q 1/241 used in mobile communications, e.g. GSM H01Q1/247, H01Q1/248 take precedence
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds

Abstract

Systems and methods for determining user equipment (UE) locations within a wireless network using reference signals of the wireless network are described. The disclosed systems and methods utilize a plurality of in-phase and quadrature (I/Q) samples generated from signals provided by receive channels associated with two or more antennas of the wireless system. Based on received reference signal parameters the reference signal within the signals from each receive channel among the receive channels is identified. Based on the identified reference signal from each receive channel, an angle of arrival between a baseline of the two or more antennas and incident energy from the UE to the two or more antennas is determined. That angle of arrival is then used to calculate the location of the UE. The angle of arrival may be a horizontal angle of arrival and/or a vertical angle of arrival.

Claims

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

buffering a plurality of in-phase and quadrature (I/Q) samples generated from signals provided by receive channels associated with two or more antennas;

receiving reference signal parameters that describe a reference signal within the signals;

identifying the reference signal within the signals from each receive channel among the receive channels;

based on the identified reference signal from each receive channel, determining an angle of arrival between a baseline of the two or more antennas and incident energy from the UE to the two or more antennas; and

utilizing the angle of arrival to calculate the location of the UE.

2. The method of claim 1, wherein the step of identifying the reference signal includes determining a start time of the reference signal using the reference signal parameters and the plurality of buffered I/Q samples.

3. The method of claim 1, the step of identifying the reference signal includes peak detecting a matched filter output associated with each receive channel to identify a particular I/Q sample among the plurality of I/Q samples that is closest to a start time of the reference signal.

4. The method of claim 1, wherein the step of determining the angle of arrival includes determining a sub-sample estimation of a direct line of sight (DLOS) flight time from the UE to each antenna among the two or more antennas.

5. The method of claim 4, wherein the DLOS flight time from the UE to each antenna is used to determine a time difference of arrival of the reference signal between the two or more antennas.

6. The method of claim 4, wherein the DLOS flight time from the UE to each antenna is used to determine a phase shift between individual subcarriers of the reference signal.

7. The method of claim 1, wherein the two or more antennas are located in one sector of a cell tower.

8. The method of claim 1, wherein a distance between the two or more antennas is small relative to a distance to the UE from the two or more antennas.

9. The method of claim 1, wherein a reference signal includes a sounding reference signal (SRS) or a demodulation reference signal (DMRS).

10. The method of claim 1, wherein the angle of arrival is associated with a line of bearing (LOB) between a serving sector of a cell tower and the UE.

11. The method of claim 10, further comprising:

utilizing the angle of arrival to determine a second LOB between a non-serving sector of the cell tower and the UE.

12. The method of claim 11, further comprising:

utilizing the angle of arrival to determine a third LOB between a non-serving sector of a second cell tower and the UE.

13. A method for determining an elevation of a user equipment (UE) in a wireless system, the method comprising:

buffering a plurality of in-phase and quadrature (I/Q) samples generated from signals provided by receive channels associated with two or more antenna elements of a sector antenna pair, wherein one antenna element among the two or more antenna elements is displaced in a vertical direction with respect to another antenna element among the two or more antenna elements;

receiving reference signal parameters that describe a reference signal within the signals;

identifying the reference signal within the signals from each receive channel among the receive channels;

based on the identified reference signal from each receive channel, determining a vertical angle of arrival between a baseline of the sector antenna pair and incident energy from the UE to the two or more antenna elements; and

utilizing the vertical angle of arrival to calculate the elevation of the UE.

14. The method of claim 13, wherein two or more antenna elements are located in a single antenna enclosure of the sector antenna pair.

15. The method of claim 13, wherein two or more antenna elements are located in different antenna enclosures of the sector antenna pair.

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

buffering a plurality of in-phase and quadrature (I/Q) samples generated from signals provided by receive channels associated with two or more antennas including multiple antenna elements, wherein one antenna element among the multiple antenna elements is displaced in a vertical direction with respect to another antenna element among the multiple antenna elements;

receiving reference signal parameters that describe a reference signal within the signals;

identifying the reference signal within the signals from each receive channel among the receive channels;

based on the identified reference signal from each receive channel, determining a horizontal angle of arrival between a baseline of the antennas and incident energy from the UE to the two or more antennas and a vertical angle of arrival between the baseline of the antennas and incident energy from the UE to the two or more antennas; and

utilizing the horizontal angle of arrival and the vertical angle of arrival to calculate the position of the UE.

17. The method of claim 16, wherein the horizontal angle of arrival and the vertical angle of arrival are each associated with a line of bearing (LOB) between a serving sector of a cell tower and the UE.

18. The method of claim 17, further comprising:

utilizing the horizontal angle of arrival to determine a second LOB between a non-serving sector of the cell tower and the UE.

19. The method of claim 17, further comprising:

utilizing the vertical angle of arrival to determine a second vertical angle of arrival between a non-serving sector of a second cell tower and the UE.

20. The method of claim 16, further comprising:

clustering two or more coherent receiver channels among the receiver channels;

forming a group unit from the clusters; and

synchronizing the group unit using external timing inputs.