TDOA/GPS Hybrid Wireless Location System

• US 20080248811A1
• Filed: 06/17/2008
• Published: 10/09/2008
• Est. Priority Date: 12/30/2003
• Status: Active Grant

• Current Assignee: Skyhook Holding, Inc. (Liberty Broadband Corp.)
• Original Assignee: TruePosition Incorporated
• Inventors: Anderson, Robert J., Maloney, John E.
• Granted Patent: US 7,925,274 B2
• Time in Patent Office: Days
• US Class Current: 455/456.1
• CPC Class Codes: G01S 19/09 providing processing capability normally carried out by the receiver
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

A method and system for enhancing the accuracy and robustness of locations determined for a mobile wireless transceiver in a cellular telephone communications system integrating location-related information both from an assisted GPS device embedded in the mobile unit and from infrastructure-based facilities that extract signal characteristic data at networked base stations. Available supporting collateral information may be additionally evaluated in the location determinations to provide location estimates of enhanced robustness and accuracy.

Claims

1. A method for the determination of the location of a mobile station (MS) equipped with embedded GPS signal reception capability and equipped to operate within a wireless communications network (WCN), the method comprising:

using a serving land station of the WCN, providing assistance data to a MS to be located, said assistance data enhancing the ability of the MS to receive GPS signals and extract time of arrival (TOA) or pseudorange measures;

at the serving land station, receiving GPS data from the MS to be located, wherein said GPS data comprises TOA or pseudorange measures;

at a land station equipped with location-measurement facilities, receiving a communications-band signal from said MS to be located and using the location-measurement facilities to extract location-related characteristic data from the communications-band signal, wherein said location-related characteristic data extracted from the communications-band signal is a function of the geographic location of said MS relative to said land station equipped with location-measurement facilities; and

at a land station equipped for location-determination calculations, performing location-determination calculations using the GPS data and the extracted location-related characteristic data to derive an estimated location for the MS.

2. A method as recited in claim 1, wherein said TOA or pseudorange measures are communicated by said MS to be located to said serving land station.

3. A method as recited in claim 1, further comprising communicating the GPS data and the extracted location-related characteristic data to said land station equipped for location-determination calculations.

4. A method as recited in claim 1, wherein said location-related characteristic data extracted from the communications-band signal includes time of arrival (TOA) data.

5. A method as recited in claim 1, wherein said location-related characteristic data extracted from the communications-band signal includes time difference of arrival (TDOA) data.

6. A method as recited in claim 1, wherein said location-related characteristic data extracted from the communications-band signal includes angle of arrival (AOA) data.

7. A method as recited in claim 1, wherein said location-related characteristic data extracted from the communications-band signal includes data concerning signal strength or propagation loss (PL).

8. A method as recited in claim 1, wherein said location-related characteristic data extracted from the communications-band signal includes timing advance (TA) data.

9. A method as recited in claim 1, further comprising using collateral information in performing said location-determination calculations.

10. A method as recited in claim 1, wherein said method is employed to achieve applicable accuracy requirements for emergency services.

11. A system for the determination of the location of a mobile station (MS) equipped with embedded GPS signal reception capability and equipped to operate within a wireless communications network, comprising:

means for receiving GPS data for use in location-determination calculations, said GPS data being received from a MS to be located;

a land station equipped with location-measurement facilities and a receiver for receiving from said MS to be located a wireless communications-band signal and using the location-measurement facilities to extract location-related characteristic data from the communications-band signal, wherein said location-related characteristic data extracted from the communications-band signal is a function of the geographic location of said MS relative to said land station equipped with location-measurement facilities; and

a land station equipped for location-determination calculations, including a processor for performing location-determination calculations using the GPS data and the extracted location-related characteristic data to derive an estimated location for the MS.

12. A system as recited in claim 11, further comprising means for communicating the GPS data and the extracted location-related characteristic data to said land station equipped for location-determination calculations.

13. A system as recited in claim 11, wherein said location-related characteristic data extracted from the communications-band signal includes time of arrival (TOA) data.

14. A system as recited in claim 11, wherein said location-related characteristic data extracted from the communications-band signal includes time difference of arrival (TDOA) data.

15. A system as recited in claim 11, wherein said location-related characteristic data extracted from the communications-band signal includes angle of arrival (AOA) data.

16. A system as recited in claim 11, wherein said location-related characteristic data extracted from the communications-band signal includes data concerning signal strength or propagation loss (PL).

17. A system as recited in claim 11, wherein said location-related characteristic data extracted from the communications-band signal includes timing advance (TA) data.

18. A system as recited in claim 11, further comprising using collateral information in performing said location-determination calculations.

19. A system as recited in claim 11, wherein said system achieves applicable accuracy requirements for emergency services.

20. A system as recited in claim 11, further comprising providing assistance data to the MS to be located, said assistance data enhancing the ability of the MS to receive GPS signals and extract TOA or pseudorange measures, wherein said TOA or pseudorange measures are then communicated to the said land station equipped with location-measurement facilities.

21. A system as recited in claim 11, further comprising means for providing assistance data to the MS to be located, said assistance data enhancing the ability of the MS to receive GPS signals and extract TOA or pseudorange measures.

22. A method for the determination of the location of a mobile station (MS) equipped with embedded GPS signal reception capability and equipped to operate within a wireless communications network, the method comprising:

(a) providing assistance data to a MS to be located, said assistance data enabling the MS to receive GPS signals and extract TOA or pseudorange measures;

(b) at a land station equipped with location-measurement facilities, receiving a communications-band signal from said MS to be located and using the location-measurement facilities to extract location-related characteristic data from the communications-band signal;

(c) communicating the TOA or pseudorange measures and the extracted location-related characteristic data to a land station equipped for location-determination calculations; and

(e) at said land station equipped for location-determination calculations, performing location-determination calculations using the GPS data and the extracted location-related characteristic data to derive an estimated location for the MS.

23. A method as recited in claim 22, wherein said location-related characteristic data extracted from the communications-band signal includes time of arrival (TOA) data.

24. A method as recited in claim 22, wherein said location-related characteristic data extracted from the communications-band signal includes time difference of arrival (TDOA) data.

25. A method as recited in claim 22, wherein said location-related characteristic data extracted from the communications-band signal includes angle of arrival (AOA) data.

26. A method as recited in claim 22, wherein said location-related characteristic data extracted from the communications-band signal includes data concerning signal strength or propagation loss (PL).

27. A method as recited in claim 22, wherein said location-related characteristic data extracted from the communications-band signal includes timing advance (TA) data.

28. A method as recited in claim 22, further comprising using collateral information in performing said location-determination calculations.

29. A method as recited in claim 22, wherein said method is employed to achieve applicable accuracy requirements for emergency services.

30. A method as recited in claim 22, wherein the wireless communications network is a GSM network, and the communications-band signal received from said MS complies with a GSM air interface specification.

31. A method as recited in claim 22, wherein the wireless communications network is a non-GSM network, and the communications-band signal received from said MS complies with a non-GSM air interface specification.

32. A system for the determination of the location of a mobile station (MS) equipped with embedded GPS signal reception capability and equipped to operate within a wireless communications network, the system comprising:

means for providing assistance data to a MS to be located, said assistance data enabling the MS to receive GPS signals and extract TOA or pseudorange measures;

a land station equipped with location-measurement facilities and configured to receive a communications-band signal from said MS to be located and to use the location-measurement facilities to extract location-related characteristic data from the communications-band signal; and

a land station equipped for location-determination calculations and configured to perform location-determination calculations using the GPS data and the extracted location-related characteristic data to derive an estimated location for the MS.

33. A system as recited in claim 32, wherein said location-related characteristic data extracted from the communications-band signal includes time of arrival (TOA) data.

34. A system as recited in claim 32, wherein said location-related characteristic data extracted from the communications-band signal includes time difference of arrival (TDOA) data.

35. A system as recited in claim 32, wherein said location-related characteristic data extracted from the communications-band signal includes angle of arrival (AOA) data.

36. A system as recited in claim 32, wherein said location-related characteristic data extracted from the communications-band signal includes data concerning signal strength or propagation loss (PL).

37. A system as recited in claim 32, wherein said location-related characteristic data extracted from the communications-band signal includes timing advance (TA) data.

38. A system as recited in claim 32, further comprising means for using collateral information in performing said location-determination calculations.

39. A system as recited in claim 32, further comprising means for communicating the TOA or pseudorange measures and the extracted location-related characteristic data to said land station equipped for location-determination calculations.

40. A system as recited in claim 32, wherein the wireless communications network is a GSM network, and the communications-band signal received from said MS complies with a GSM air interface specification.

41. A system as recited in claim 32, wherein the wireless communications network is a non-GSM network, and the communications-band signal received from said MS complies with a non-GSM air interface specification.