Method and apparatus for processing position information in a mobile device

• US 7,254,404 B2
• Filed: 04/13/2004
• Issued: 08/07/2007
• Est. Priority Date: 04/13/2004
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Global Locate Incorporated (Broadcom, Inc.)
• Inventors: Abraham, Charles, van Diggelen, Frank
• Primary Examiner(s): Nguyen; Duc
• Assistant Examiner(s): LEE, JUSTIN YE
• Application Number:
  US10/823,504
• Publication Number:
  US 20050228589A1
• Time in Patent Office: 1,211 Days
• Field of Search: 4554561-457, 455/237.1, 455/238.1, 342/450, 342454-457, 342/458, 342461-462
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/396 Determining accuracy or reliability of position or pseudorange measurements
• CPC Class Codes: G01S 19/42 Determining position

Abstract

Method and apparatus for processing position information in a mobile device is described. In one example, a request for a position to be computed within a predefined period of time is received. A plurality of positions is calculated within the predefined period of time. At least one of the plurality of positions is cached in a position cache. Accuracy data is derived with respect to at least one of the plurality of positions. A best position stored in the position cache is identified in response to the accuracy data. The best position may be sent to a server in communication with the mobile device.

Claims

1. A method of processing position information in a mobile device, comprising:

receiving a request for a position to be computed within a predefined period of time;

computing a best position and a corresponding indicia of accuracy within said predefined period of time;

comparing said indicia of accuracy to a threshold;

retaining said best position in a cache in response to said indicia of accuracy satisfying said threshold;

searching said cache for a previously retained position having a best accuracy in response to said indicia of accuracy failing said threshold; and

sending an indication of no accurate position to a server in response to no previously retained position being stored in said cache.

2. The method of claim 1, further comprising:

sending said best position to a server in communication with said mobile device.

3. The method of claim 1, further comprising:

identifying a previously retained position in said cache having a best accuracy in response to said indicia of accuracy failing said threshold;

sending said previously retained position to a server in communication with said mobile device.

4. The method of claim 1, wherein computing a best position and a corresponding indicia of accuracy comprises:

calculating a plurality of positions within said predefined period of time;

caching at least one of said plurality of positions;

deriving an indicia of accuracy with respect to at least one of said plurality of positions; and

identifying said best position and said corresponding indicia of accuracy.

5. The method of claim 4, wherein said best position is identified before expiration of said predefined period of time.

6. The method of claim 4, wherein said best position is a last calculated position of said plurality of positions with respect to expiration of said predefined period of time.

7. The method of claim 1, wherein said request is received from a server in communication with said mobile device.

8. The method of claim 1, wherein said request is generated by said mobile device.

9. The method of claim 1, wherein said indicia of accuracy is derived from at least one of a covariance matrix of a Kalman filter, pseudorange residual data, and dilution of precision data.

10. The method of claim 1, further comprising:

sending said best position and said indicia of accuracy to a server in communication with said mobile device.

11. A method of processing position information in a mobile device, comprising:

receiving a request for a position to be computed within a predefined period of time;

computing a best position and a corresponding indicia of accuracy within said predefined period of time;

comparing said indicia of accuracy to a threshold;

retaining said best position in a cache in response to said indicia of accuracy satisfying said threshold;

identifying a previously retained position in said cache having a best accuracy in response to said indicia of accuracy failing said threshold;

comparing said best accuracy of said previously retained position to a second threshold; and

sending said previously retained position to a server in communication with said mobile device in response to said best accuracy satisfying said second threshold.

12. The method of claim 11, further comprising:

searching said cache for another previously retained position having a second best accuracy in response to said best accuracy failing said threshold.

13. The method of claim 11, wherein said indicia of accuracy is derived from at least one of a covariance matrix of a Kalman filter, pseudorange residual data, and dilution of precision data.

14. The method of claim 11, further comprising:

sending said best position and said indicia of accuracy to a server in communication with said mobile device.

15. The method of claim 11, wherein said best position is identified before expiration of said predefined period of time.

16. The method of claim 11, wherein computing a best position and a corresponding indicia of accuracy comprises:

calculating a plurality of positions within said predefined period of time;

caching at least one of said plurality of positions in a position cache;

deriving accuracy data with respect to at least one of said plurality of positions; and

identifying a best position stored in said position cache in response to said accuracy data.

17. The method of claim 16, wherein said best position is a last calculated position of said plurality of positions with respect to expiration of said predefined period of time.

18. The method of claim 16, further comprising:

storing at least a portion of said accuracy data in said position cache.

19. The method of claim 16, wherein deriving an indicia of accuracy comprises:

computing said indicia of accuracy for the at least one of said plurality of positions stored in said position cache; and

storing each said indicia of accuracy in said position cache.

20. The method of claim 11, further comprising:

sending said best position to a server in communication with said mobile device.

21. The method of claim 11, wherein said request is received from a server in communication with said mobile device.

22. The method of claim 11, wherein said request is generated by said mobile device.