Compensation of propagation delays of wireless signals

• US 8,929,914 B2
• Filed: 10/25/2012
• Issued: 01/06/2015
• Est. Priority Date: 01/23/2009
• Status: Active Grant

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Inventors: Davis, Richard W.
• Primary Examiner(s): TRAN, CONGVAN
• Application Number:
  US13/660,689
• Publication Number:
  US 20130045755A1
• Time in Patent Office: 803 Days
• Field of Search: 455/404.2, 455/456.1, 455/456.5, 455/456.6, 455/67.11, 455/115.1
• US Class Current: 455/456.1
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 56/006 using known positions of transmitter and receiver

Abstract

Propagation delay offsets of wireless signals are compensated. Compensation is accomplished through determination of an effective wireless signal propagation delay that accounts for signal path delay and propagation delay over the air. Such determination is based at least in part on statistical analysis of accurate location estimates of reference positions throughout a coverage sector or cell, and location estimates of the reference positions generated through time-of-flight (TOF) measurements of wireless signals. Determination of propagation or signal path delay offset also is attained iteratively based at least in part on reference location estimates and TOF location estimates. High-accuracy location estimates such as those obtained through global navigation satellite systems are employed as reference location estimates. Position of probes or wireless beacons, deployed throughout a sector or cell, also are employed as reference locations. Compensation of propagation delay offset improves accuracy of conventional TOF location estimates and radio network performance.

Claims

1. A method, comprising:

determining, by a system comprising a processor, first location estimate data indicative of a first set of location estimates associated with a location and second location estimate data indicative of a second set of location estimates associated with the location, wherein the first set of location estimates and the second set of location estimates are determined based on different location assessment techniques;

mapping, by the system, first sector identification data determined from the first location estimate data with second sector identification data determined from the second location estimate data; and

based on the mapping, calibrating, by the system, sector bearing data that represents a position of a user equipment within a defined sector of an access point device, with respect to a centerline determined between a receiver antenna and an emitter antenna of the access point device.

2. The method of claim 1, further comprising:

determining, by the system, propagation delay offset data based on a correlation between first location estimate data and the second location estimate data, wherein the determining the propagation delay offset data comprises determining the propagation delay offset data based on a determination of a degree to which the first set of location estimates are linearly related to the second set of location estimates; and

based on the propagation delay offset data, calibrating, by the system, a propagation timing measurement associated with a wireless signal based on the propagation delay offset data.

3. The method of claim 1, further comprising:

selecting, by the system, model data indicative of a propagation model that facilitates a determination of the first set of location estimates.

4. The method of claim 1, wherein the determining comprises determining , the first set of location estimate data based on time-of-flight measurement data associated with a wireless signal transmitted between the access point device and the user equipment.

5. The method of claim 1, further comprising:

based on the calibrating, determining, by the system, timing delay error data indicative of disparate timing delay errors for respective portions of the sector.

6. The method of claim 1, wherein the calibrating comprises compensating for disparate degrees of multipath effects in disparate sections of the sector.

7. The method of claim 1, wherein the mapping comprises mapping first pilot code sequence data determined from the first location estimate data with second pilot code sequence data determined from the second location estimate data.

8. The method of claim 1, further comprising:

determining, by the system, the second set of location estimates based on global positioning system data.

9. The method of claim 1, further comprising:

determining, by the system, the second set of location estimates based on global navigation satellite system data.

10. The method of claim 1, further comprising:

determining, by the system, the second set of location estimates based on network planning data.

11. A system, comprising:

a memory to store executable instructions; and

a processor coupled to the memory that facilitates execution of the executable instructions to perform operations, comprising;

determining first location estimate data and second location estimate data, wherein the first location estimate data is generated based on a first estimation of a location of a device and the second location estimate data is generated based on a second estimation of the location of the device,

determining first sector identification data based on the first location estimate data and second sector identification data based on the second location estimate data; and

based on mapping the first sector identification data with the second sector identification data, adjusting a sector bearing that represents the location within a defined sector of an access point device, with respect to a centerline between a receiver antenna and an emitter antenna of the access point device.

12. The system of claim 11, wherein the operations further comprise:

determining angular information associated with the first location estimate data and the second location estimate data, and

based on the angular information, updating wireless propagation timing measurement data.

13. The system of claim 11, wherein the device is an access point device and the operations further comprise:

receiving the first location estimate data associated with the access point device from a network data store.

14. The system of claim 13, wherein the access point device comprises a pseudo-stationary access point device and wherein the receiving comprises receiving the first location estimate data in response to a change in the location of the access point device.

15. The system of claim 11, wherein the second location estimate data is determined based on time-of-flight measurement data associated with a signal transmitted between a base station device and the device.

16. A computer-readable storage device comprising executable instructions that, in response to execution, cause a system comprising a processor to perform operations, comprising:

correlating a first set of location estimates and a second set of location estimates that are associated with a common location, wherein the first set of location estimates and the second set of location estimates are determined based on different location assessments;

mapping first sector identification data determined from the first location estimate data with second sector identification data determined from the second location estimate data; and

based on the mapping, determining sector bearing data that represents a position of a user equipment within a defined sector of an access point device, with respect to a determined centerline between a receiver antenna and an emitter antenna of the access point device.

17. The computer-readable storage device of claim 16, wherein the correlating comprises determining a variance between the first set of location estimates and the second set of location estimates.

18. The computer-readable storage device of claim 16, wherein the operations further comprise:

based on the sector bearing data, determining timing delay error data indicative of disparate timing delay errors for respective portions of the sector.

19. The computer-readable storage device of claim 16, wherein the operations further comprise:

based on the sector bearing data, compensating for disparate degrees of multipath effects in disparate sections of the sector.

20. The computer-readable storage device of claim 16, wherein the first sector identification data comprises first pilot code sequence data and the second sector identification data comprises second pilot code sequence data.