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

• US 7,127,257 B2
• Filed: 03/12/2002
• Issued: 10/24/2006
• Est. Priority Date: 12/27/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Girerd, Richard, Biacs, Zoltan, Riley, Wyatt
• Primary Examiner(s): FERGUSON, KEITH
• Application Number:
  US10/097,041
• Publication Number:
  US 20030125046A1
• Time in Patent Office: 1,687 Days
• Field of Search: 455/456.1, 455/456.2, 455/456.3, 455/456.4, 455/456.5, 455/456.6, 455/457, 455/414.1, 455/414.2, 455/404.1, 455/404.2, 455/426.1, 455/432.1, 455/550.1, 455/500, 455/517, 455/561, 455/524, 455/525, 455/446, 455/423, 455/424, 455/425, 455/445
• 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 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.

2. The method as claimed in claim 1, wherein the position of the mobile station is determined by the position determining entity when the mobile station receives a base station signal from a base station absent from the base station almanac

3. The method as claimed in claim 1, 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.

4. 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 programed 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.

5. The wireless communication network as claimed in claim 4, 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.

6. The wireless communication network as claimed in claim 4, 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.

7. The wireless communication network as claimed in claim 4, 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.

8. The wireless communication network as claimed in claim 4, 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.

9. The wireless communication network as claimed in claim 4, 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 front the positions of the mobile stations and the distances between the base station and the mobile station.

10. The wireless communication network as claimed in claim 4, wherein the position determining entity computes a dine 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.

11. The wireless communication network as claimed in claim 4, 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.

12. The wireless communication network as claimed in claim 4, 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.