System and method for measuring and locating a mobile station signal in a wireless communication system

• US 6,246,884 B1
• Filed: 08/19/1998
• Issued: 06/12/2001
• Est. Priority Date: 08/19/1998
• Status: Expired due to Fees

• Current Assignee: SigmaOne Communications Corp.
• Original Assignee: SigmaOne Communications Corp.
• Inventors: Weiss, Anthony, Karmi, Yair
• Primary Examiner(s): Trost, William G.
• Assistant Examiner(s): SMITH, SHEILA B
• Application Number:
  US09/136,277
• Time in Patent Office: 1,028 Days
• Field of Search: 455/9, 455/67.1, 455/115, 455/161.3, 455/226.1, 455/226.2, 455/440, 455/447, 455/448, 455/456, 455/457, 342/450, 342/457
• US Class Current: 455/521
• CPC Class Codes: G01S 5/0081 Transmission between base stations
• CPC Class Codes: G01S 5/02 using radio waves using satellite radio beacon systems for determining position G01S19/00
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A communication system comprises a reference base station which collects one or more signal features of a mobile station signal. The reference base station determines a first location parameter of the mobile station signal it receives. The reference base station forwards the signal features to an auxiliary base station. Using the signal features, the auxiliary base station creates a replica of the mobile station signal as transmitted by the mobile station. The auxiliary base station correlates the replica with a same mobile station signal as received at the auxiliary base station in order to determine a second set of signal features. The auxiliary base station uses the second set of signal features to determine a second location parameter. The position of the mobile station is determined using the first and second location parameters. The process may be repeated at a plurality of auxiliary base stations and for a plurality of different location parameters in order to improve the accuracy of the determination of mobile station location.

Claims

1. A method of measuring transmission of a transmitter within a communication system, the method comprising the steps of:

collecting a first set of one or more signal features of a first transmitter signal received at a first receiver wherein said first set of signal features comprises a data content of said first transmitter signal;

forwarding said first set of signal features to a second receiver;

creating a replica of said first transmitter signal at said second receiver in response to said first set of signal features;

correlating said replica with a second transmitter signal received at said second receiver; and

determining a second set of one or more signal features for said second transmitter signal as received at said second receiver;

determining a first location parameter of said first transmitter signal in response to said first set of signal features;

determining a second location parameter of said second transmitter signal in response to said second set of signal features; and

estimating a position of said transmitter in response to said first and second location parameters.

2. The method of claim 1, further comprising the step of performing error detection at said first receiver to determine said data content.

3. The method of claim 1, wherein said first set of signal features is distributed to a plurality of receivers and corresponding location parameters of said transmitter are determined and wherein said step of estimating said position of said transmitter comprises the step of estimating said position of said transmitter using said corresponding location parameters.

4. The method of claim 1, wherein said first set of signal features is determined in response to information regarding a model, type or manufacturer of said transmitter.

5. The method of claim 1, wherein said first set of signal features comprises a phase trajectory of said first transmitter signal.

6. The method of claim 1, wherein said first set of signal features comprises frequency deviations of said first transmitter signal.

7. The method of claim 1, wherein said first set of signal features comprises frequency variations along a portion of said first transmitter signal.

8. The method of claim 1, wherein said first set of signal features comprises Doppler shift information corresponding to said first transmitter signal.

9. The method of claim 1, wherein said step of correlating is carried out over a range of parameters and wherein said range of parameters is limited in response to said first set of signal features.

10. The method of claim 1, wherein said second receiver is co-located with a base station of said communication system.

11. The method of claim 10, wherein said transmitter is outside of a coverage area corresponding to said base station.

12. The method of claim 1, wherein said first transmitter signal comprises an emergency voice call.

13. The method of claim 1, wherein said first transmitter signal comprises a known location beacon.

20. The method of claim 1, wherein said first receiver communicates with said transmitter.

21. The method of claim 1, wherein said transmitter is within a coverage area corresponding to said first receiver.

22. The method of claim 1, wherein said first receiver receives said transmitter signals at a higher signal to noise ratio than any other receiver in said communication system.

14. An apparatus for measuring a mobile station transmission within a communication system comprising:

means for collecting a first set of one or more signal features of a first mobile station signal received at a reference base station, wherein said first set of signal features comprises a data content of said mobile station signal;

means for forwarding said first set of signal features to an auxiliary base station;

means for creating a replica of said first mobile station signal at said auxiliary base station in response to said first set of signal features;

means for correlating said replica with a second mobile station signal received at said auxiliary base station in order to determine a second set of one or more signal features for said mobile station signal as received at said auxiliary base station;

means responsive to said first set of signal features for determining a first location parameter of said first mobile station signal;

means responsive to said second set of signal features for determining a second location parameter of said second mobile station signal; and

means for estimating a position of said mobile station in response to said first and second location parameters.

15. The apparatus of claim 14, wherein said reference base station performs error detection to determine said data content.

16. The apparatus of claim 14, wherein said means for correlating operates over a range of parameters and wherein said range of parameters is limited by said first set of signal features.

17. The apparatus of claim 14, wherein co-channel interference prevents said auxiliary base station from detecting and demodulating said second mobile station signal.

18. The apparatus of claim 14, wherein a low signal to noise ratio prevents said auxiliary base station from detecting and demodulating said second mobile station signal.

19. The apparatus of claim 14, wherein said auxiliary base station is co-located with a fully functioning base station of said communication system.

23. The apparatus of claim 16, wherein said reference base station receives said mobile station signal at a higher signal to noise ratio than any other base station in said communication system.