Mobile positioning using intergrated ad-hoc network

• US 20050075111A1
• Filed: 12/05/2001
• Published: 04/07/2005
• Est. Priority Date: 12/06/2000
• Status: Active Grant

• Current Assignee: University of Surrey
• Original Assignee: University of Surrey
• Inventors: Tafazolli, Rahim, Yap, Jung Houn, Ghaheri-Niri, Shahram
• Granted Patent: US 7,231,216 B2
• Time in Patent Office: Days
• US Class Current: 455/456.100
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station
• CPC Class Codes: G01S 5/02 using radio waves using satellite radio beacon systems for determining position G01S19/00
• CPC Class Codes: G01S 5/0289 of multiple transceivers, e.g. in ad hoc networks
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• 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 positioning method for a cellular communications system includes evaluating an initial position estimate of a target mobile station having an initial area of uncertainty, evaluating a position estimate of a further mobile station of the system, estimating distance between the target and further mobile stations and using the position and distance estimates to evaluate a new position estimate of the target mobile station having a reduced area of uncertainty. Bi-circular and tri-circular methods are described.

Claims

1. A mobile station positioning method for a cellular communications system comprising,

evaluating an initial position estimate of a target mobile station, the initial position estimate having an initial area of uncertainty,

evaluating a position estimate of a further mobile station also having an area of uncertainty,

evaluating an estimate of distance between said target mobile station and said further mobile station, and

using said position and distance estimates to evaluate a new position estimate of the target mobile station having an area of uncertainty less than said initial area of uncertainty.

2. The method as claimed in claim 1 including evaluating position estimates of at least two said further mobile stations, evaluating the corresponding said distance estimates and using all the position and distance estimates to evaluate said new position estimate.

3. The method as claimed in claim 1 wherein each said position estimate is evaluated from signals transmitted between the respective mobile station and a group of three neighboring base stations of the system.

4. The method as claimed in claim 3 wherein said position estimates are all evaluated using the same group of neighboring base stations.

5. The method as claimed in claim 1 wherein said initial position estimate and the position estimate of a said further mobile station are evaluated from signals transmitted between the respective mobile stations and different pairs of a group of three neighboring base stations of the system.

6. The method as claimed in an one of claims 1 wherein said position estimates are evaluated using Timing Advance signals.

7. The method as claimed in claim 1 wherein said position estimates are evaluated using a cellular positioning method.

8. The method as claimed in claim 7 wherein said cellular position method comprises at least one positioning method selected from a Timing Advance-based method, a Time Difference of Arrival method and an Observed Time Difference method.

9. The method as claimed in claim 1 wherein said position estimates are evaluated using a GPS-assisted method.

10. The method as claimed in claim 1 wherein said distance estimate is evaluated in a said mobile station.

11. The method as claimed in claim 9 wherein said distance estimate is evaluated using an Opportunity Driven Multiple Access (ODMA) protocol.

12. The method as claimed in claim 1 for use in a GSM cellular communications system.

14. The cellular communications system adapted to perform the method according to claim 1.

15. The system according to claim 14 being a GSM cellular communications system.

18. The method as claimed in claim 2 wherein each said position estimate is evaluated from signals transmitted between the respective mobile station and a group of three neighboring base stations of the system.

19. The method as claimed in claim 18 wherein said position estimates are all evaluated using the same group of neighboring base stations.

20. The method as claimed in claim 2 wherein said initial position estimate and the position estimate of a said further mobile station are evaluated from signals transmitted between the respective mobile stations and different pairs of a group of three neighboring base stations of the system.

13. A mobile station positioning method for a cellular communications system comprising,

evaluating an initial position estimate of a target mobile station, the initial position estimate having an initial area of uncertainty,

evaluating a position estimate of a further mobile station having a further area of uncertainty,

evaluating an estimate of distance between said target mobile station and said further mobile station, and

reducing said initial area of uncertainty so that the resultant reduced area of uncertainty does not extend beyond said further area of uncertainty by more than the estimated distance.

16. (canceled)

17. (canceled)