Aiding in a satellite positioning system

• US 7,236,883 B2
• Filed: 12/04/2003
• Issued: 06/26/2007
• Est. Priority Date: 08/14/2000
• Status: Expired due to Term

• Current Assignee: CSR Limited (Qualcomm, Inc.)
• Original Assignee: SIRF Technology Incorporated (Qualcomm, Inc.)
• Inventors: Zhang, Gengsheng, Vantalon, Nicolas Patrick, Garin, Lionel Jacques, Peng, Leon Kuo-Liang
• Primary Examiner(s): Jeanglaude; Gertrude A.
• Application Number:
  US10/515,808
• Publication Number:
  US 20060095206A1
• Time in Patent Office: 1,300 Days
• Field of Search: 701207-215, 342/357.01, 342/357.05, 342/357.06, 342/357.1, 342/357.12, 455/456.1, 455/456.6, 455/3.01
• US Class Current: 701/213
• CPC Class Codes: G01S 19/235 Calibration of receiver components
• CPC Class Codes: G01S 19/254 relating to Doppler shift of satellite signals
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset

Abstract

The invention relates to an aided Global Positioning System (GPS) subsystem within a wireless device. The wireless device includes a wireless processing section capable of receiving signals from a wireless network and a GPS subsystem having a radio frequency (RF) front-end capable of receiving a GPS satellite signal. The wireless processing section of the wireless device receives an external clock and determines the offset between the clock in the wireless processing section and that of the external clock. The GPS subsystem then receives the offset information from the wireless processing section, information related to the nominal frequency of the wireless processing section clock and the wireless processing section clock. Using this information and the GPS clock in the GPS subsystem, the GPS subsystem determines an acquiring signal, which is related to a frequency offset between the GPS clock and the network clock. The GPS subsystem then acquires GPS satellite signals in an acquiring unit though the use of the acquiring signal.

Claims

1. An aided Global Positioning System (GPS) subsystem within a wireless device, wherein the wireless device has a wireless processing section having a wireless processing section clock, the wireless processing section capable of receiving signals from a wireless network including a network clock signal and capable of generating a first offset indicative of the difference between the network clock and the wireless processing section clock, and the GPS subsystem has a radio frequency (RF) front-end capable of receiving a GPS satellite signal, the aided GPS subsystem comprising:

a GPS clock; and

a GPS processor section that receives the GPS clock and at least one signal from the wireless processing section including the first offset, and in response produces at least one acquiring signal that is utilized by an acquiring unit to acquire the GPS satellite signal.

2. The aided GPS subsystem of claim 1, wherein the at least one signal from the wireless processing section may include a digital message.

3. The aided GPS subsystem of claim 1, wherein the GPS processing section includes:

a GPS clock processor that receives the GPS clock and the first offset and produces a second offset representative of the difference between the GPS clock and a network clock that is external to the wireless device; and

a GPS carrier and code generator that produces the at least one acquiring signal in response to receiving the offset signal from the GPS clock processor.

4. The aided GPS subsystem of claim 3, wherein the at least one signal from the wireless processing section may include a digital message.

5. The aided GPS subsystem of claim 3, wherein the GPS clock processor includes an offset counter that receives the GPS clock and the first offset and produces an offset counter output signal that is representative of the difference between the GPS clock and wireless processing section clock signal.

6. The aided GPS subsystem of claim 5, wherein the at least one signal from the wireless processing section includes information about the clock within the wireless processing section.

7. The sided GPS subsystem of claim 6, wherein the information about the clock within the wireless processing section includes the wireless processing section clock signal.

8. The aided GPS subsystem of claim 5 further including an offset combiner that produces the second offset signal in response to combining the offset counter output signal with the first offset signal from the wireless processor.

9. The aided GPS subsystem of claim 8, wherein the GPS carrier and code generator includes:

a Doppler correction unit that produces Doppler correction values; and

an offset combiner unit that combines the Doppler correction values with the second offset signal and produces a total offset signal that is utilized by die GPS carrier and code generator in producing the at least one acquiring signal.

10. The aided GPS subsystem of claim 3, wherein the GPS carrier and code generator includes:

a Doppler prediction model that produces Doppler correction values; and

an offset combiner unit that combines the Doppler correction values with a second offset signal and produces a total offset signal that is utilized by the GPS carrier and code generator in producing the at least one acquiring signal.

11. An aided Global Positioning System (GPS) subsystem within a wireless device, wherein the wireless device has a wireless processing section having a wireless processing section clock, the wireless processing section capable of receiving signals from a wireless network including a network clock signal and capable of generating a first offset indicative of the difference between the network clock and the wireless processing section clock, and the GPS subsystem has a radio frequency (RF) front-end capable of receiving a GPS satellite signal, the aided GPS subsystem comprising:

a GPS clock;

means for receiving the GPS clock and at least one signal from the wireless processing section including the first offset; and

means for producing in response to the receiving means at least one acquiring signal that is utilized by an acquiring unit to acquire the GPS satellite signal.

12. The aided GPS subsystem of claim 11, wherein the at least one signal from the wireless processing section may include a digital message.

13. The aided GPS subsystem of claim 11, wherein the GPS processing section includes:

means for receiving the GPS clock and the first offset;

means for producing a second offset representative of the difference between the GPS clock and a network clock that is external to the wireless device; and

means for producing the at least one acquiring signal in response to receiving the offset signal from the receiving means.

14. The aided GPS subsystem of claim 13, wherein the offset signal producing means includes an offset counter that receives the GPS clock and the first offset and produces an offset counter output signal that is representative of the difference between the GPS clock and wireless processing section clock signal.

15. The aided GPS subsystem of claim 14 further including an offset combiner that produces the second offset signal in response to combining the offset counter output signal with the first offset signal from the wireless processor.

16. The aided GPS subsystem of claim 15, wherein the producing acquiring signal means includes:

means for producing Doppler correction values; and

means for combining the Doppler correction values with the second offset signal and produces a total offset signal that is utilized by a GPS carrier and code generator in producing the at least one acquiring signal.

17. A method for aiding a Global Positioning System (GPS) subsystem within a wireless device, wherein the wireless device has a wireless processing section capable of receiving signals from a wireless network and the GPS subsystem has a radio frequency (RF) front-end capable of receiving a GPS satellite signal, the method comprising:

receiving a GPS clock, wireless processing section clock, message having information related to the wireless processing section clock nominal frequency, and a message having information related to an offset between the wireless processing section clock and a network clock external to the wireless device;

determining am acquiring signal in response to receiving the GPS clock, wireless processing section clock, wireless processing section clock nominal frequency message, and the offset message, wherein the acquiring signal is related to a frequency offset between the GPS clock and the network clock;

acquiring the GPS satellite signal in an acquiring unit that utilizes the acquiring signal.

18. The method of claim 17, wherein the acquiring signal includes a digital message having information related to the frequency offset between the GPS clock and the network clock.

19. The method of claim 17, wherein determining the acquiring signal further includes;

determining an offset between the GPS clock and the wireless processing section clock; and

determining the frequency offset between the GPS clock and network clock from the offset between the GPS clock and wireless processing section and the offset between the wireless processing section clock and the network clock.

20. The method of claim 19, wherein determining the acquiring signal further includes combining the frequency offset between the GPS clock and the network clock with the Doppler correction value.

21. The method of claim 20 further including adjusting a numerically controlled (NCO) with the combined frequency offset between the GPS clock and the network clock with the Doppler correction value.

22. The method of claim 21, wherein acquiring includes utilizing a correlator to acquire the received GPS satellite signal.

23. The method of claim 21, wherein acquiring includes utilizing a matched filter to acquire the received GPS satellite signal.

24. A signal-bearing medium having software for aiding a Global Positioning System (GPS) subsystem within a wireless device, wherein the wireless device has a wireless processing section capable of receiving signals from a wireless network and the GPS subsystem has a radio frequency (RF) front-end capable of receiving a GPS satellite signal, the signal-bearing medium comprising:

logic for receiving a GPS clock, wireless processing section clock, message having information related to the wireless processing section clock nominal frequency, and a message having information related to an offset between the wireless processing section clock and a network clock external to the wireless device;

logic for determining an acquiring signal in response to receiving the GPS clock, wireless processing section clock, wireless processing section clock nominal frequency message, and the offset message, wherein the acquiring signal is related to a frequency offset between the GPS clock and the network clock;

logic for acquiring the GPS satellite signal in an acquiring unit that utilizes the acquiring signal.

25. The signal-bearing medium of claim 24, wherein the logic for acquiring the GPS satellite signal includes a digital message having information related to the frequency offset between the GPS clock and the network clock.

26. The signal-bearing medium of claim 24, wherein determining logic the acquiring signal further includes:

logic for determining an offset between the GPS clock and the wireless processing section clock; and

logic for determining the frequency offset between the GPS clock and network clock from the offset between the GPS clock and wireless processing section and the offset between the wireless processing section clock and the network clock.

27. The signal-bearing medium of claim 26, wherein the logic for determining the acquiring signal further includes combining the frequency offset between the GPS clock and the network clock with a Doppler correction value.

28. The signal-bearing medium of claim 27 further including logic for adjusting a numerically controlled oscillator (NCO) with the combined frequency offset between the GPS clock and the network clock with the Doppler correction value.

29. The signal-bearing medium of claim 28, wherein the acquiring logic includes logic for utilizing a correlator to acquire the received GPS satellite signal.

30. The signal-bearing medium of claim 28, wherein the acquiring logic includes logic for utilizing a matched filter to acquire the received GPS satellite signal.