Use of mobile stations for determination of base station location parameters in a wireless mobile communication system

• US 20030125046A1
• Filed: 03/12/2002
• Published: 07/03/2003
• Est. Priority Date: 12/27/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Biacs, Zoltan, Riley, Wyatt, Girerd, Richard
• Granted Patent: US 7,127,257 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• 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 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 5/021 Calibration, monitoring or correction G01S5/0252 takes precedence
• CPC Class Codes: G01S 5/0226 Transmitters
• CPC Class Codes: G01S 5/0236 Assistance data, e.g. base station almanac
• CPC Class Codes: G01S 5/0242 Determining the position of transmitters to be subsequently used in positioning G01S5/0289 takes precedence
• CPC Class Codes: H04W 64/003 locating network equipment

Abstract

In a wireless communication network, base station antenna positions and time offsets are stored in a base station almanac data base along with other information used for obtaining the most reliable mobile station position fixes under a variety of conditions. The system uses the position fixes of mobile stations and terrestrial ranging information to determine base station antenna positions and base station timing offsets. The base station antenna positions are determined during normal mobile station position determinations, in order to maintain and improve the antenna location data, and to correct for change or relocation of the base station antennas. It is possible to recover quickly from a loss of cell sector identity during relocation of a base station antenna, and to ensure accuracy of mobile station position determination based on ranging from the base stations, and rapid acquisition of position data from mobile stations having global satellite receivers.

Claims

1. In a wireless communication network, a method of determining the position of a base station, the method comprising:

(a) determining positions of at least one mobile station in communication with the base station; and

(b) determining the position of the base station from the positions of the mobile station(s) and from signals transmitted between the base station and the mobile station(s).

2. The method as claimed in claim 1, wherein the mobile stations have global satellite receivers, and the positions of the mobile stations are determined from signals received by the mobile stations from global satellites.

3. The method as claimed in claim 1, wherein the positions of the mobile stations are determined by Advanced Forward Link Trilateration (AFLT) of each mobile station from base stations having known positions.

4. The method as claimed in claim 1, which includes measuring path delays of the signals transmitted between the base station and the mobile stations to determine distances between the base station and the mobile stations, and determining the position of the base station from the position of the mobile stations and the distances between the base station and the mobile stations.

5. The method as claimed in claim 1, wherein the mobile stations are hybrid telephone handsets including global satellite receivers, the positions of the mobile stations are determined from signals received by the mobile stations from global satellites, and the position of the bas e station is determined from the positions of the mobile stations using Advanced Forward Link Trilateration (AFLT).

6. The method as claimed in claim 1, where a single mobile station is at different positions at different times, and can provide more than one measurement for determination of the base station location.

7. The method as claimed in claim 1, which further includes computing a time bias of at least one of the mobile stations, and using the time bias in the calculation of the base station position.

8. The method as claimed in claim 1, which further includes computing a time bias in the base station transmitter from the determined positions of the mobile stations, from time biases of the mobile stations, and from the signals transmitted between the base station and the mobile stations.

9. The method as claimed in claim 1, which further includes using error estimates in the determined positions of the mobile stations and in time biases of the mobile stations for the determination of the position of the base station.

10. The method as claimed in claim 1, which includes estimating antenna elevation of the base station as an average antenna height above an average elevation of the mobile stations.

11. The method as claimed in claim 1, which includes estimating antenna elevation of the base station as an average antenna height above an elevation obtained by look-up of a terrain elevation database for the elevation at an estimated position of the base station.

12. The method as claimed in claim 1, which is performed in response to the mobile stations receiving a base station signal from a base station absent from a base station almanac.

13. The method as claimed in claim 1, wherein the position of the base station antenna determined from the positions of the mobile stations is compared to a position for the base station contained in a base station almanac in order to verify the position for the base station contained in the base station almanac.

14. In a wireless communication network having base stations for communication with mobile stations, a base station almanac, and a position determining entity for determining the positions of the mobile stations from signals transmitted between the base stations and the mobile stations, a method of maintaining base station location information in the base station almanac, the method comprising:

(a) when the position of a mobile station is determined by the position determining entity independent of the position of a base station in communication range of the mobile station, determining the distance between the base station and the mobile station from signals transmitted between the base station and the mobile station; and

(b) modifying the base station almanac to include corrected base station location information for the base station when the distance between the base station and the mobile station indicates that the base station location information in the base station almanac is incorrect or relatively inaccurate.

15. The method as claimed in claim 14, wherein the position of the mobile station is determined by the position determining entity [independent of the position of a base station in communication range of the mobile station] when the mobile station receives a base station signal from a base station absent from the base station almanac.

16. The method as claimed in claim 14, which includes determining the position of the base station from positions of a plurality of the mobile stations and signals transmitted between the base station and the plurality of the mobile stations, and modifying the base station almanac by storing the determined position of the base station in the base station almanac.

17. A wireless communication network comprising:

(a) base stations for communication with mobile stations; and

(b) at least one position determining entity for determining positions of the mobile stations based on signals transmitted between the base stations and the mobile stations, and information stored in a base station almanac;

wherein the wireless communication network is programmed for determining the position of a base station from the positions of the mobile stations and from signals transmitted between the base station and the mobile stations, and for using the determined position of the base station to maintain base station location information in the base station almanac.

18. The wireless communication network as claimed in claim 17, wherein the position of the base station is determined when a mobile station receives a signal from the base station and the base station is found to be absent from the base station almanac.

19. The wireless communication network as claimed in claim 17, wherein the base station almanac is updated with the determined position of the base station when the determined position of the base station indicates that base station location information in the base station almanac indicates an incorrect position for the base station.

20. The wireless communication network as claimed in claim 17, wherein the mobile stations have global satellite receivers, and the position determining entity determines the positions of the mobile stations from signals received by the mobile stations from global satellites.

21. The wireless communication network as claimed in claim 17, wherein the position determining entity determines the positions of the mobile stations by Advanced Forward Link Trilateration (AFLT) of each mobile station from base stations having known positions.

22. The wireless communication network as claimed in claim 17, wherein the position determining entity measures path delays of the signals transmitted between the base station and the mobile stations to determine distances between the base station and the mobile stations, and determines the position of the base station from the positions of the mobile stations and the distances between the base station and the mobile station.

23. The wireless communication network as claimed in claim 17, wherein the position determining entity computes a time bias in the base station transmitter from the position of the mobile stations and from the signals transmitted between the base station and the mobile stations.

24. The wireless communication network as claimed in claim 17, wherein the position determining entity estimates antenna elevation of the base station as an average antenna height above an average elevation of the mobile stations.

25. The wireless communication network as claimed in claim 17, wherein the position determining entity estimates antenna elevation of the base station as an average antenna height above an elevation obtained by look-up of a terrain elevation database for the elevation at an estimated position of the base station.