Method and apparatus for receiving a global positioning system signal using a cellular acquisition signal

• US 7,053,824 B2
• Filed: 11/06/2001
• Issued: 05/30/2006
• Est. Priority Date: 11/06/2001
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Global Locate Incorporated (Broadcom, Inc.)
• Inventors: Abraham, Charles
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US09/993,335
• Publication Number:
  US 20030085837A1
• Time in Patent Office: 1,666 Days
• Field of Search: 342/357.09, 342/357.1, 342/357.15, 375/356
• US Class Current: 342/357.64
• 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

1. A method, comprising:

obtaining a time synchronization signal from a cellular network at a global positioning system (GPS) handheld device without a subscription to the cellular network using a front end only capable of receiving signals from said cellular network;

determining a timing offset responsive to the time synchronization signal;

determining a time of day responsive to the timing offset without having to have a subscription to the cellular network; and

processing satellite trajectory data within the GPS handheld device using the time of day.

2. The method of claim 1 wherein the step of processing comprises:

determining at least one of a satellite position and a satellite velocity responsive to the time of day.

3. The method of claim 2 further comprising determining a window of delay search for receiving a GPS signal at the GPS handheld device responsive to the satellite position.

4. The method of claim 2 further comprising determining a window of frequency search for receiving a GPS signal at the GPS handheld device responsive to the satellite velocity.

5. The method of claim 2 further comprising computing position of the GPS handheld device responsive to the satellite position.

6. The method of claim 2 further comprising computing velocity of the GPS handheld device responsive to the satellite velocity.

7. The method of claim 1 further comprising determining a window of delay search for receiving a GPS signal at the GPS handheld device responsive to the time of day.

8. The method of claim 1 further comprising:

receiving a GPS signal to the GPS handheld device; and

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

9. A method, comprising:

obtaining a time synchronization signal from a cellular network without transmitting a cellular signal to the cellular network using a front end only capable of receiving signals from said cellular network;

determining a timing offset responsive to the time synchronization signal;

determining a time of day responsive to the timing offset; and

processing satellite trajectory data within the GPS handheld device using the time of day.

10. The method of claim 9 wherein the step of processing comprises:

determining at least one of a satellite position and a satellite velocity responsive to the time of day.

11. The method of claim 10 further comprising determining a window of delay search for receiving a GPS signal at the GPS handheld device responsive to the satellite position.

12. The method of claim 10 further comprising determining a window of frequency search for receiving a GPS signal at the GPS handheld device responsive to the satellite velocity.

13. The method of claim 10 further comprising computing position of the GPS handheld device responsive to the satellite position.

14. The method of claim 10 comprising computing velocity of the GPS handheld device responsive to the satellite velocity.

15. The method of claim 9 further comprising determining a window of delay search for receiving a GPS signal at the GPS handheld device responsive to the time of day.

16. The method of claim 9 further comprising:

receiving a GPS signal to the GPS handheld device; and

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