METHOD AND APPARATUS FOR RECEIVING A GLOBAL POSITIONING SYSTEM SIGNALUSING A CELLULAR ACQUISITION SIGNAL

• US 20030085837A1
• Filed: 11/06/2001
• Published: 05/08/2003
• Est. Priority Date: 11/06/2001
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Global Locate Incorporated (Broadcom, Inc.)
• Inventors: Abraham, Charles
• Granted Patent: US 7,053,824 B2
• Time in Patent Office: Days
• US Class Current: 342/357.1
• CPC Class Codes: G01S 19/235 Calibration of receiver components
• CPC Class Codes: G01S 19/252 Employing an initial estimate of location in generating assistance data
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: G01S 19/29 carrier including Doppler, related G01S19/246 takes precedence
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: H04B 1/3805 with built-in auxiliary receivers

Abstract

Method and apparatus for a GPS device that uses at least one cellular acquisition signal is described. More particularly, a GPS device is configured to receive at least one cellular acquisition signal for obtaining benefits associated with AGPS with only a small subset of AGPS circuitry to interact with a cell phone network. This facilitates use of GPS devices without subscription to a cell phone service provider, thus avoiding cellular subscription fees.

Claims

2. A method for receiving a Global Positioning System (GPS) signal to a GPS handheld device, comprising:

obtaining a time synchronization burst from a cellular network;

determining a timing offset responsive to the time synchronization burst; and

determining a time of day responsive to the timing offset for receiving the GPS signal without having to have a subscription to the cellular network.

3. The method of claim 2 further comprising determining at least one of a satellite position and a satellite velocity responsive to the time of day.

4. The method of claim 3 further comprising determining a window of delay search for receiving the GPS signal responsive to the satellite position.

5. The method of claim 3 further comprising determining a window of frequency search for receiving the GPS signal responsive to the satellite velocity.

6. The method of claim 3 further comprising computing position of the GPS handheld device responsive to the satellite position.

7. The method of claim 3 further comprising computing velocity of the GPS handheld device responsive to the satellite velocity.

8. The method of claim 2 further comprising determining a window of delay search for receiving the GPS signal responsive to the time of day.

9. The method of claim 2 further comprising:

receiving the GPS signal to the GPS handheld device; and

coherent averaging responsive to the time of day to synchronize to navigation data bits.

10. A method for determining position of a Global Positioning System (GPS) handheld device in proximity to a cellular basestation of a cellular network, comprising:

obtaining at least one of location information and identification information from the cellular basestation; and

determining a position estimate of the GPS handheld device responsive to the at least one of location information and identification information without having to have fee-based access to the cellular network.

11. The method of claim 10 further comprising computing a pseudorange responsive to the position estimate.

12. The method of claim 11 further comprising determining a window of delay search for receiving GPS signals responsive to the pseudorange.

13. The method of claim 11 further comprising synchronizing coherent averaging to navigation data bits responsive to the pseudorange.

14. The method of claim 10 further comprising computing a pseudorange rate responsive to the position estimate.

15. The method of claim 14 further comprising determining a window of frequency search responsive to the pseudorange rate for receiving a GPS signal.

16. The method of claim 10 wherein the identification information is a cell identifier.

17. The method of claim 16 further comprising providing a lookup table relating basestation locations to cell identifiers, wherein the step of determining the position estimate comprises using the cell identifier to obtain a cellular basestation location of the cellular basestation.

18. The method of claim 10 wherein the location information is a cellular basestation location of the cellular basestation.

19. A Global Positioning System (GPS) mobile device, comprising:

at least one antenna;

a cellular acquisition signal front end couple to the at least one antenna to receive a cellular acquisition signal;

a GPS signal front end coupled to the at least one antenna to receive a GPS signal;

a GPS/cellular processor coupled to the GPS front end and to the cellular acquisition front end, the GPS/cellular processor is configured with a GPS baseband processor in electrical communication with the GPS front end and a cellular acquisition signal baseband processor in electrical communication with the cellular acquisition signal front end;

a reference oscillator coupled to the GPS/cellular processor;

a general purpose processor coupled to the cellular acquisition signal baseband processor and to the GPS baseband processor; and

memory coupled to the general-purpose processor.

20. The GPS mobile device of claim 19 wherein the GPS mobile device does not comprise a cellular transmitter.

21. The GPS mobile device of claim 19 wherein the GPS mobile device is not integrated with a cellular handset.

22. The GPS mobile device of claim 19 wherein the cellular acquisition signal front end and GPS signal front end are integrated in a single integrated circuit.

23. The GPS mobile device of claim 19 wherein the cellular acquisition signal baseband processor and the GPS baseband processor are integrated in a single integrated circuit.

24. The GPS mobile device of claim 19 further comprising a timekeeping counter coupled to the reference oscillator and in electrical communication with the cellular acquisition signal baseband processor and the GPS baseband processor.

25. A method for receiving a Global Positioning System (GPS) signal, comprising:

obtaining a frequency correction burst from a cellular network;

determining a frequency offset responsive to the frequency correction burst; and

determining a window of frequency search responsive to the frequency offset for receiving the GPS signal without having to transmit a cellular signal to the cellular network.

26. A method for receiving a Global Positioning System (GPS) signal to a GPS handheld device, comprising:

obtaining a time synchronization burst from a cellular network;

determining a timing offset responsive to the time synchronization burst; and

determining a time of day responsive to the timing offset for receiving the GPS signal without having to transmit a cellular signal to the cellular network.

27. The method of claim 26 further comprising determining at least one of a satellite position and a satellite velocity responsive to the time of day.

28. The method of claim 27 further comprising determining a window of delay search for receiving the GPS signal responsive to the satellite position.

29. The method of claim 27 further comprising determining a window of frequency search for receiving the GPS signal responsive to the satellite velocity.

30. The method of claim 27 further comprising computing position of the GPS handheld device responsive to the satellite position.

31. The method of claim 27 further comprising computing velocity of the GPS handheld device responsive to the satellite velocity.

32. The method of claim 26 further comprising determining a window of delay search for receiving the GPS signal responsive to the time of day.

33. The method of claim 26 further comprising:

receiving the GPS signal to the GPS handheld device; and

coherent averaging responsive to the time of day to synchronize to navigation data bits.

34. A method for determining position of a Global Positioning System (GPS) handheld device in proximity to a cellular basestation of a cellular network, comprising:

obtaining at least one of location information and identification information from the cellular basestation; and

determining a position estimate of the GPS handheld device responsive to the at least one of location information and identification information without having to transmit a cellular signal to the cellular network.

1. A method for receiving a Global Positioning System (GPS) signal, comprising:

obtaining a frequency correction burst from a cellular network;

determining a frequency offset responsive to the frequency correction burst; and

determining a window of frequency search responsive to the frequency offset for receiving the GPS signal without having to have a subscription to the cellular network.

35. The method of claim 34 further comprising computing a pseudorange responsive to the position estimate.

36. The method of claim 35 further comprising determining a window of delay search for receiving GPS signals responsive to the pseudorange.

37. The method of claim 35 further comprising synchronizing coherent averaging to navigation data bits responsive to the pseudorange.

38. The method of claim 34 further comprising computing a pseudorange rate responsive to the position estimate.

39. The method of claim 38 further comprising determining a window of frequency search responsive to the pseudorange rate for receiving a GPS signal.

40. The method of claim 39 further comprising providing a lookup table relating basestation locations to cell identifiers wherein the step of determining the position estimate comprises using the cell identifier to obtain a cellular basestation location of the cellular basestation.

41. The method of claim 34 wherein the location information is a cellular basestation location of the cellular basestation.

39-1. The method of claim 34 wherein the identification information is a cell identifier.