Transmitter identifier database for enhanced GPS performance

• US 8,131,464 B2
• Filed: 03/05/2010
• Issued: 03/06/2012
• Est. Priority Date: 10/19/2004
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Farmer, Dominic Gerard, Arcens, Suzanne F.
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): Sample, Jonathan L
• Application Number:
  US12/718,663
• Publication Number:
  US 20100156706A1
• Time in Patent Office: 732 Days
• Field of Search: None
• 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 a position of a mobile station, the method comprising:

storing a database of transmitter identifiers and associated mobile station position information, wherein the mobile station position information is one or more previously determined positions of the mobile station;

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

determining the position of the mobile station using the signal.

2. The method of claim 1, further comprising:

receiving a transmitter identifier through a wireless signal; and

locating the received transmitter identifier and associated mobile station position information in the database;

wherein the uncertainty region is a function of the mobile station position information associated with the received transmitter identifier.

3. The method of claim 1, wherein the transmitter is a cellular telecommunications base station.

4. The method of claim 3, 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 mobile station position information associated with the identifier.

5. The method of claim 1, wherein the uncertainty region comprises a region based upon mobile station position information associated with one transmitter identifier.

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

7. The method of claim 1, wherein the uncertainty region is further a function of platform dynamics.

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

9. The method of claim 1, wherein the uncertainty region is a function of the smallest of a region defined by mobile station position information in the database, a region of predefined size, and a region based upon platform dynamics.

10. The method of claim 1, further comprising:

limiting a first region (R₀) for a first position (x₀, y₀) as a function of the smallest of a region defined by mobile station position information stored in the database, a region of predefined size, and a region based upon assumed platform dynamics;

limiting a second region (R₁) for a second position (x₁, y₁) as a function of the smallest of a region defined by mobile station position information stored in the database, a region of predefined size, and a region based upon assumed platform dynamics; and

wherein the uncertainty region used to search for the signal is an area of overlap of the first region (R₀) and the second region (R₁).

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

12. The method of claim 1, wherein maintaining the database comprises recalculating mobile station position information based upon previous mobile station position information and current mobile station position information.

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

measuring a signal propagation delay; and

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

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

16. The method of claim 1, further comprising storing an “

out-of-network”

database when the transmitter identifiers and associated mobile station position information are located outside a mobile station home network.

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

out-of-network”

database to a network.

18. The method of claim 1, wherein searching for a signal comprises searching for a satellite vehicle signal.

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

receiving a transmitter identifier from a base station;

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

searching for a signal based upon the mobile station position information from the position database; and

determining precise mobile station position based upon an acquired signal.

20. The method of claim 19, wherein the base station is a cellular telecommunications base station.

21. The method of claim 19, wherein the mobile station position information is one or more previously determined positions of the mobile station.

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

23. The method of claim 22, further comprising calculating an approximate mobile station position associated with the received transmitter identifier based upon precise mobile station position and at least one precise mobile station position determined earlier in time.

24. The method of claim 19, further comprising comparing the received transmitter identifier to transmitter identifiers stored in the position database to determine if the mobile station communicated with the base station at an earlier time.

25. The method of claim 24, further comprising adding the transmitter identifier to the position database in the event that the mobile station did not previously communicate with the base station.

26. The method of claim 25, further comprising storing mobile station position information associated with the added transmitter identifier in the position database.

27. The method of claim 19, wherein searching for a signal comprises searching for a satellite vehicle signal.

28. 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 transmitter identifier and mobile station position information associated with the transmitter identifier, wherein the mobile station position information is one or more previously determined positions of the mobile station;

wherein the two-way communication system, position location system, mobile control, and memory communicate such that a signal is searched based upon the mobile station position information in the position database.

29. The mobile station of claim 28, wherein the transmitter identifier is an identifier for a cellular telecommunications base station.

30. The mobile station of claim 28, wherein the two way communication system receives a transmitter identifier from a base station and the signal search is based on mobile station position information associated with the transmitter identifier in the position database.

31. The mobile station of claim 28, wherein the mobile station position information comprises precise position information for the mobile station at a particular time, and approximate position information for the identifier.

32. The mobile station of claim 31, wherein approximate position information is determined from the precise position information.

33. The mobile station of claim 28, wherein the signal is a satellite vehicle signal.

34. A mobile station apparatus comprising:

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

means for receiving a transmitter identifier from a base station;

means for searching the database to locate mobile station position information associated with the received transmitter identifier;

means for searching for a signal in an uncertainty region that is a function of the located mobile station position information; and

means for determining the position of the mobile station assisting based upon signal acquisition.

35. A processor comprising:

a position location system and a mobile control;

memory comprising a position database comprising at least one transmitter identifier and mobile station position information associated with the transmitter identifier, wherein the mobile station position information is one or more previously determined positions of a mobile station;

wherein the memory communicates with the position location system and the mobile control such that the position location system searches for a signal based upon the mobile station position information in the position database.