Mobile cellular identification database for enhanced GPS performance

• US 7,706,975 B2
• Filed: 10/18/2005
• Issued: 04/27/2010
• Est. Priority Date: 10/19/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Arcens, Suzanne, Farmer, Dominic Gerard
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): SAMPLE, JONATHAN L
• Application Number:
  US11/253,359
• Publication Number:
  US 20060129317A1
• Time in Patent Office: 1,652 Days
• Field of Search: 701/213, 701/207, 342/357.15
• US Class Current: 701/213
• 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 19/08 providing integrity information, e.g. health of satellites or quality of ephemeris data
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/26 involving a sensor measurement for aiding acquisition or tracking
• CPC Class Codes: G01S 5/0236 Assistance data, e.g. base station almanac
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A mobile station database of cellular identifications and associated position information is stored in mobile station memory. The mobile station uses the position information in the database to assist in determining a current position for the mobile based on an identifier, such as cell ID, base station BSIC, PSC, or carrier frequency. A satellite vehicle signal is searched in an uncertainty region that is a function of position information associated with the current identifier. The uncertainty region can be limited by assumed platform dynamics via predefined velocity and acceleration information. Time maintenance for the mobile station can also be achieved through known approximate position from the position database and measurement of a single satellite vehicle propagation delay. The mobile station can compare a position determination obtained through satellite vehicle signals with position database information to determine the validity of that position. Out-of-network position information is also stored in the position database and is optionally shared with a network.

Claims

1. A method for determining position of a mobile station, comprising:

storing a database of cellular identifications and associated position information in mobile station memory, wherein the position information is one or more previously determined positions of the mobile station;

searching for a satellite vehicle signal in an uncertainty region that is a function of the position information in the database; and

assisting in mobile station position determination with the database.

2. The method of claim 1 wherein storing a database comprises:

storing at least one identifier selected from the group consisting of cell ID, BSIC identifier, PSC identifier, and base station carrier frequency; and

storing position information associated with the identifier.

3. The method of claim 1 wherein the uncertainty region comprises a region based upon position information associated with one identifier selected from the group consisting of cellular identification, BSIC identifier, PSC identifier, and base station carrier frequency.

4. The method of claim 1 wherein the uncertainty region comprises a region of predefined size.

5. The method of claim 1 wherein the uncertainty region comprises a region based upon assumed platform dynamics.

6. The method of claim 1 further comprising limiting the uncertainty region by selecting the smaller of an uncertainty region that is a function of position information in the database, an uncertainty region of predefined size, and an uncertainty region based upon assumed platform dynamics.

7. The method of claim 6 wherein assumed platform dynamics are based upon predefined velocity and acceleration information.

8. The method of claim 1 further comprising limiting the uncertainty region by selecting the smaller region (R₀) of an uncertainty region that is a function of position information stored in the database, an uncertainty region of predefined size, and an uncertainty region based upon assumed platform dynamics, for an initial position (x₀, y₀).

9. The method of claim 8 further comprising selecting the smaller region (R₁) of an uncertainty region that is a function of position information stored in the database, an uncertainty region of predefined size, and an uncertainty region based upon assumed platform dynamics, for a position (x₁, y₁).

10. The method of claim 9 further comprising searching for a satellite vehicle signal in the area of overlap of regions (R₀) and (R₁).

11. The method of claim 1 further comprising maintaining the database based upon updated mobile station position information.

12. The method of claim 11 wherein maintaining the database comprises recalculating position information based upon previous position information and current position information.

13. The method of claim 1 further comprising performing time maintenance for the mobile station based upon position information in the database.

14. The method of claim 13 wherein performing time maintenance comprises:

determining a position for the mobile station based upon position information in the database;

measuring a satellite vehicle signal propagation delay; and

determining time based upon the position and the satellite vehicle signal propagation delay.

15. The method of claim 1 further comprising performing a sanity check on a position determination based upon position information in the database.

16. The method of claim 2 further comprising storing an “

out-of-network”

database when the identifier and associated position information are located outside the mobile station home network.

17. The method of claim 16 further comprising transferring the “

out-of-network”

database to a network.

18. A method of determining mobile station position, comprising:

receiving at least one identifier selected from the group consisting of cell ID, BSIC identifier, PSC identifier, and base station carrier frequency, from a base station;

searching a position database stored in the mobile station for the identifier, wherein the position database includes at least one identifier and position information associated with the identifier, wherein the position information is one or more previously determined positions of the mobile station;

searching for a satellite vehicle signal based upon the position information from the position database; and

determining precise mobile station position based upon satellite vehicle signal acquisition.

19. The method of claim 18 further comprising storing precise mobile station position associated with the received identifier.

20. The method of claim 19 further comprising calculating an approximate position associated with the received identifier based upon precise mobile station position and at least one precise mobile station position determined earlier in time.

21. The method of claim 18 further comprising comparing the received identifier to identifiers stored in the position database to determine if the mobile station communicated with the base station at an earlier time.

22. The method of claim 21 further comprising adding the identifier to the position database in the event that the mobile station did not previously communicate with the base station.

23. The method of claim 22 further comprising storing position information associated with the identifier in the position database.

24. A mobile station apparatus comprising:

a two-way communication system;

a position location system;

mobile station control; and

memory comprising a position database comprising at least one identifier selected from the group consisting of cell ID, BSIC identifier, PSC identifier, and base station carrier frequency, and position information associated with the identifier, wherein the position information is one or more previously determined positions of the mobile station;

wherein the position location system, mobile control, and memory communicate such that a satellite vehicle signal is searched based upon the position information in the position database.

25. The mobile station of claim 24 wherein the position information comprises precise position information associated with the identifier for the mobile station at a particular time, and approximate position information for the identifier.

26. The mobile station of claim 25 wherein approximate position information is determined from the precise position information.

27. A mobile station apparatus comprising:

means for storing a database of cellular identifications and associated position information in mobile station memory, wherein the position information is one or more previously determined positions of the mobile station;

means for searching for a satellite vehicle signal in an uncertainty region that is a function of the position information in the database; and

means for assisting in mobile station position determination with the database.

28. A processor comprising:

memory comprising a position database comprising at least one identifier selected from the group consisting of cell ID, BSIC identifier, PSC identifier, and base station carrier frequency, and position information associated with the identifier, wherein the position information is one or more previously determined positions of a mobile station including a position location system and a mobile control;

wherein the memory communicate with the position location system and the mobile control such that a satellite vehicle signal is searched based upon the position information in the position database.