Computationally-Efficient Estimation of the Location of a Wireless Terminal Based on Pattern Matching

• US 20080299993A1
• Filed: 08/14/2008
• Published: 12/04/2008
• Est. Priority Date: 05/22/2006
• Status: Abandoned Application

• Current Assignee: Polaris Wireless Incorporated
• Original Assignee: Polaris Wireless Incorporated
• Inventors: Gordon, Scot Douglas, Martin, Robert Lewis, Spain, David Stevenson JR.
• Application Number:
  US12/191,777
• Publication Number:
  US 20080299993A1
• Time in Patent Office: Days
• US Class Current: 455/456.5
• CPC Class Codes: G01S 19/06 employing an initial estimate of the location of the receiver as aiding data or in generating aiding data
• CPC Class Codes: G01S 19/17 Emergency applications
• CPC Class Codes: G01S 19/252 Employing an initial estimate of location in generating assistance data
• CPC Class Codes: G01S 5/0252 Radio frequency fingerprinting
• CPC Class Codes: H04W 4/021 Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
• CPC Class Codes: H04W 4/029 Location-based management or tracking services
• CPC Class Codes: H04W 4/33 for indoor environments, e.g. buildings
• CPC Class Codes: H04W 4/48 for in-vehicle communication
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A method of using a non-GPS-derived technique to estimate the location of an Assisted-GPS-enabled wireless terminal for the purposes of generating location-specific assistance data for the wireless terminal is disclosed. The wireless terminal then uses the assistance data to acquire and process one or more GPS signals and to derive information that is probative of the wireless terminal'"'"'s location. The GPS-derived location information is then combined with non-GPS-derived location to form an estimate of the location of the wireless terminal that is better than can be derived from either alone. This combination of GPS-derived and non-GPS techniques is particularly useful when the wireless terminal can only acquire one or two GPS signals because it is not possible to determine the location of the wireless terminal with only two GPS signals alone.

Claims

1. A method comprising:

receiving a measurement of a first characteristic of a first signal that is processed by a wireless terminal;

designating at least one of a plurality of possible locations of said wireless terminal as improbable; and

estimating the location of said wireless terminal based on a comparison of said measurement of said first characteristic of said first signal to a predicted value of said first characteristic of said first signal for at least one of said plurality of possible locations not designated as improbable.

2. The method of claim 1 further comprising:

receiving a measurement of said first characteristic of a second signal that is processed by said wireless terminal; and

estimating the location of said wireless terminal based on a comparison of said measurement of said first characteristic of said second signal to a predicted value of said first characteristic of said second signal for at least one of said plurality of possible locations not designated as improbable.

3. The method of claim 2 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when a ranking of said measurement of said first characteristic of said first signal and said measurement of said first characteristic of said second signal differs from a ranking of said predicted value of said first characteristic of said first signal and said predicted value of said first characteristic of said second signal at said possible location.

4. The method of claim 1 further comprising:

receiving a measurement of a second characteristic of said first signal; and

estimating the location of said wireless terminal based on a comparison of said measurement of said second characteristic of said first signal to a predicted value for said second characteristic of said first signal for at least one of said plurality of possible locations not designated as improbable.

5. The method of claim 1 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when a difference of said measurement of said first characteristic of said first signal and said predicted value of said first characteristic of said first signal exceeds a threshold.

6. The method of claim 1 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when said location is not provided wireless telecommunications service by a base station that is known to be providing service to said wireless terminal.

7. The method of claim 1 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when said location is not within the neighboring coverage area of a base station that is known to be a neighboring base station of said wireless terminal.

8. The method of claim 1 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when a measurement of said first characteristic of a second signal is not received when it would have been received if said wireless terminal were, in fact, at that location.

9. The method of claim 1 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when a measurement of a second characteristic of said first signal is not received when it would have been received if said wireless terminal were, in fact, at that location.

10. The method of claim 1 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when a measurement of a second characteristic of a second signal is not received when it would have been received if said wireless terminal were, in fact, at that location.

11. A method comprising:

receiving a measurement of a first characteristic of a first signal that is processed by said wireless terminal;

designating a possible location as improbable when said location is not provided wireless telecommunications service by a first base station that is known to be providing service to said wireless terminal; and

estimating the location of said wireless terminal based on a comparison of said measurement of said first characteristic of said first signal to a predicted value of said first characteristic of said first signal for at least one of said plurality of possible locations not designated as improbable.

12. The method of claim 11 further comprising:

designating a possible location as improbable when said location is not within the neighboring coverage area of a base station that is known to be a neighboring base station of said wireless terminal.

13. The method of claim 11 further comprising:

receiving an indication that a measurement of a second characteristic of said first signal is not received; and

designating at least one of said plurality of possible locations of said wireless terminal as improbable when said measurement of said second characteristic of said first signal is not received when it would have been received if said wireless terminal were, in fact, at that location.

14. The method of claim 11 further comprising:

receiving an indication that a measurement of said first characteristic of a second signal is not received; and

designating at least one of said plurality of possible locations of said wireless terminal as improbable when said measurement is not received when it would have been received if said wireless terminal were, in fact, at that location.

15. The method of claim 14 further comprising:

designating a possible location as improbable when a ranking of said measurement of said first characteristic of said first signal and said measurement of said first characteristic of said second signal differs from a ranking of said predicted value of said first characteristic of said first signal and said predicted value of said first characteristic of said second signal at said possible location.

16. The method of claim 11 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when a difference of said measurement of said first characteristic of said first signal and said predicted value of said first characteristic of said first signal exceeds a threshold.

17. A method comprising:

receiving a measurement of a first characteristic of a first signal that is processed by said wireless terminal;

designating a possible location as improbable when said location is not within the neighboring coverage area of a first base station that is known to be a neighboring base station of said wireless terminal; and

estimating the location of said wireless terminal based on a comparison of said measurement of said first characteristic of said first signal to a predicted value of said first characteristic of said first signal for at least one of said plurality of possible locations not designated as improbable.

18. The method of claim 17 further comprising:

designating a possible location as improbable when said location is not provided wireless telecommunications service by a second base station that is known to be providing service to said wireless terminal.

19. The method of claim 17 further comprising:

receiving an indication that a measurement of a second characteristic of said first signal is not received; and

designating at least one of said plurality of possible locations of said wireless terminal as improbable when said measurement of said second characteristic of said first signal is not received when it would have been received if said wireless terminal were, in fact, at that location.

20. The method of claim 17 further comprising:

receiving an indication that a measurement of said first characteristic of a second signal is not received; and

designating at least one of said plurality of possible locations of said wireless terminal as improbable when said measurement is not received when it would have been received if said wireless terminal were, in fact, at that location.

21. The method of claim 20 further comprising:

designating a possible location as improbable when a ranking of said measurement of said first characteristic of said first signal and said measurement of said first characteristic of said second signal differs from a ranking of said predicted value of said first characteristic of said first signal and said predicted value of said first characteristic of said second signal at said possible location.

22. The method of claim 17 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when a difference of said measurement of said first characteristic of said first signal and said predicted value of said first characteristic of said first signal exceeds a threshold.

23. A method comprising:

receiving a measurement of a first characteristic of a first signal that is processed by a wireless terminal;

designating a possible location of said wireless terminal as improbable when a difference of said measurement of said first characteristic of said first signal and a predicted value of said first characteristic of said first signal exceeds a threshold; and

estimating the location of said wireless terminal based on a comparison of said measurement of said first characteristic of said first signal to a predicted value of said first characteristic of said first signal for at least one of said plurality of possible locations not designated as improbable.

24. The method of claim 23 further comprising:

receiving a measurement of said first characteristic of a second signal that is processed by said wireless terminal; and

wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises;

designating a possible location as improbable when a ranking of said measurement of said first characteristic of said first signal and said measurement of said first characteristic of said second signal differs from a ranking of said predicted value of said first characteristic of said first signal and said predicted value of said first characteristic of said second signal at said possible location.

25. The method of claim 23 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when said location is not provided wireless telecommunications service by a base station that is known to be providing service to said wireless terminal.

26. The method of claim 23 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when said location is not within the neighboring coverage area of a base station that is known to be a neighboring base station of said wireless terminal.

27. The method of claim 23 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when a measurement of said first characteristic of a second signal is not received when it would have been received if said wireless terminal were, in fact, at that location.

28. The method of claim 23 wherein designating at least one of said plurality of possible locations of said wireless terminal as improbable comprises:

designating a possible location as improbable when a measurement of a second characteristic of said first signal is not received when it would have been received if said wireless terminal were, in fact, at that location.