Method of and system for reducing a time to fix in a location-enabled receiver

• US 20060049982A1
• Filed: 06/03/2005
• Published: 03/09/2006
• Est. Priority Date: 09/03/2004
• Status: Abandoned Application

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Wells, Graham
• Application Number:
  US11/145,158
• Publication Number:
  US 20060049982A1
• Time in Patent Office: Days
• US Class Current: 342/357.290
• CPC Class Codes: G01S 19/03 Cooperating elements; Interaction or communication between different cooperating elements or between cooperating elements and receivers
• CPC Class Codes: G01S 19/256 relating to timing, e.g. time of week, code phase, timing offset

Abstract

A location-enabled wireless device includes a wireless receiver and a positioning-signal receiver. The wireless device further includes an oscillator adapted to output a reference-frequency signal to the wireless receiver and the positioning-signal receiver and a detector adapted to output a control signal upon detection of at least one of a frequency error and a phase error between wireless signals and the reference-frequency signal. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Claims

1. A location-enabled wireless device comprising:

a wireless receiver;

a positioning-signal receiver;

an oscillator adapted to output a reference-frequency signal to the wireless receiver and the positioning-signal receiver; and

a detector adapted to output a control signal upon detection of at least one of a frequency error and a phase error between wireless signals and the reference-frequency signal.

2. The location-enabled wireless device of claim 1, wherein the detector is adapted to output the control signal to a data demodulation unit of the positioning-signal receiver.

3. The location-enabled wireless device of claim 2, wherein the control signal provides an indication to the data demodulation unit that the reference-frequency of the oscillator is being updated.

4. The location-enabled wireless device of claim 2, wherein the control signal provides an indication to the data demodulation unit of a magnitude of the at least one of the frequency error and the phase error.

5. The location-enabled wireless device of claim 3, wherein the data demodulation unit is adapted to discontinue demodulation of positioning signals during a reference-frequency update.

6. The location-enabled wireless device of claim 1, wherein the detector comprises an automatic frequency control (AFC) circuit.

7. The location-enabled wireless device of claim 6, wherein the detector is adapted to periodically update the reference-frequency signal of the oscillator.

8. The location-enabled wireless device of claim 1, wherein the oscillator comprises a voltage-controlled oscillator (VCXO).

9. The device of claim 1, wherein the location-enabled wireless device comprises a mobile device.

10. The device of claim 1, wherein the positioning-signal receiver comprises a global positioning system (GPS) receiver.

11. The device of claim 1, wherein the detector is adapted to output the control signal to the positioning-signal receiver.

12. The device of claim 2, wherein the data demodulation unit comprises a digital signal processor (DSP).

13. A method of reducing a time to fix in a location-enabled wireless device, the method comprising:

receiving wireless signals;

receiving positioning signals;

outputting of a reference-frequency signal to a wireless receiver and a positioning-signal receiver;

responsive to detection of at least one of a frequency error and a phase error between wireless signals and the reference-frequency signal, outputting a control signal; and

wherein the control signal provides an indication that the reference-frequency signal is being updated.

14. The method of claim 13, wherein the control signal further provides an indication of a magnitude of the at least one of the frequency error and the phase error.

15. The method of claim 13, further comprising discontinuing demodulation of the positioning signals during a reference-frequency update.

16. The method of claim 13, wherein the step of detection further includes periodically updating the reference-frequency signal.

17. The method of claim 13, wherein the step of receiving positioning signals is in accordance with a global positioning system (GPS).

18. The method of claim 13, further comprising:

receiving the control signal; and

responsive to receipt of the control signal, discontinuing demodulation of positioning signals.

19. The method of claim 18, wherein the control signal is received by the positioning-signal receiver.

20. The method of claim 18, wherein the control signal is received by a data demodulation unit.

21. The method of claim 20, wherein the data demodulation unit comprises a digital signal processor (DSP).

22. The method of claim 13, wherein the step of outputting is performed by a detector.

23. The method of claim 22, wherein the detector comprises an automatic frequency control (AFC) circuit.