Resolving Transmit Time Uncertainty in Carrier Phase Relative Positioning

• US 20100182195A1
• Filed: 01/16/2009
• Published: 07/22/2010
• Est. Priority Date: 01/16/2009
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Garin, Lionel J.
• Application Number:
  US12/355,610
• Publication Number:
  US 20100182195A1
• Time in Patent Office: Days
• US Class Current: 342/357.220
• CPC Class Codes: G01S 19/04 providing carrier phase data
• CPC Class Codes: G01S 19/37 Hardware or software details of the signal processing chain
• CPC Class Codes: G01S 19/43 using carrier phase measurements, e.g. kinematic positioning; using long or short baseline interferometry
• CPC Class Codes: G01S 19/54 using carrier phase measurements; using long or short baseline interferometry
• CPC Class Codes: G01S 5/0284 Relative positioning

Abstract

Methods and apparatus are provided for use in electronic devices to perform carrier phase relative positioning processing.

Claims

1. A method for use with a device having an SPS receiver, the method comprising:

determining a current chip number associated with a spread-spectrum sequence in at least one received Satellite Positioning System (SPS) signal transmitted by at least one space vehicle (SV);

determining a fraction of a chip associated with at least one carrier signal phase measurement sample; and

determining at least one SV transmit time based, at least in part on a local receiver time, said current chip number, and said fraction of said chip.

2. The method as recited in claim 1, further comprising:

determining a carrier phase integer ambiguity associated with at least said at least one SV transmit time.

3. The method as recited in claim 2, further comprising:

determining at least one cumulated carrier phase measurement based, at least in part, on said at least one SV transmit time and said carrier phase integer ambiguity.

4. The method as recited in claim 3, further comprising:

determining a Double Difference (DD) Carrier Phase observable based, at least in part, on said at least one cumulated carrier phase measurement.

5. The method as recited in claim 4, wherein said DD Carrier Phase observable is associated, at least in part, with at least one other receiver of at least one other device.

6. The method as recited in claim 5, wherein said local receiver is associated with a slave receiver and said at least one other device comprises a master device.

7. The method as recited in claim 6, wherein said slave and master devices are operatively coupled together through at least a portion of a wireless network.

8. The method as recited in claim 6, further comprising:

establishing said local receiver time based, at least in part, on synchronization information associated with said master device.

9. The method as recited in claim 6, wherein said master device and said at least one SV are substantially synchronized to an SPS system time.

10. The method as recited in claim 4, further comprising:

determining a transmit time ambiguity associated with said slave device based, at least in part, on at least one DD Carrier Phase observable; and

resolving a single unknown parameter vector based, at least in part, on a transmit time ambiguity associated with said slave device, and at least one DD integer ambiguity associated with at least said at least one SV.

11. The method as recited in claim 4, further comprising:

determining a OD carrier phase linearization point based, at least in part, on said DD carrier phase observable; and

determining a relative position between at least said slave and master devices based, at least in part, on said DD carrier phase linearization point.

12. An apparatus comprising:

means for determining a current chip number associated with a spread-spectrum sequence in at least one received Satellite Positioning System (SPS) signal transmitted by at least one space vehicle (SV);

means for determining a fraction of a chip associated with at least one carrier signal phase measurement sample; and

means for determining at least one SV transmit time based, at least in part on a local receiver time, said current chip number, and said fraction of said chip.

13. The apparatus as recited in claim 12, further comprising:

means for determining a carrier phase integer ambiguity associated with at least said at least one SV transmit time.

14. The apparatus as recited in claim 13, further comprising:

means for determining at least one cumulated carrier phase measurement based, at least in part, on said at least one SV transmit time and said carrier phase integer ambiguity).

15. The apparatus as recited in claim 14, further comprising:

means for determining a Double Difference (DD) Carrier Phase observable based, at least in part, on said at least one cumulated carrier phase measurement.

16. The apparatus as recited in claim 15, wherein said DD Carrier Phase observable is associated, at least in part, with at least one other receiver of at least one other device.

17. The apparatus as recited in claim 16, wherein said local receiver is associated with a slave receiver and said at least one other device comprises a master device.

18. The apparatus as recited in claim 17, further comprising:

means for operatively coupling said slave and master devices together.

19. The apparatus as recited in claim 17, further comprising:

means for establishing said local receiver time based, at least in part, on synchronization information associated with said master device.

20. The apparatus as recited in claim 17, wherein said master device and said at least one SV are substantially synchronized to an SPS system time.

21. The apparatus as recited in claim 15, further comprising:

means for determining a transmit time ambiguity associated with said slave device based, at least in part, on at least one DD Carrier Phase observable; and

means for resolving a single unknown parameter vector based, at least in part, on a transmit time ambiguity associated with said slave device, and at least one DD integer ambiguity associated with at least said at least one SV.

22. The apparatus as recited in claim 15, further comprising:

means for determining a DD carrier phase linearization point based, at least in part, on said DD carrier phase observable; and

means for determining a relative position between at least said slave and master devices based, at least in part, on said DD carrier phase linearization point.

23. An article comprising:

a computer readable medium having stored thereon computer implementable instructions that if implemented by one or more processing units operatively enable the one or more processing unit to;

determine a current chip number associated with a spread-spectrum sequence in at least one received Satellite Positioning System (SPS) signal transmitted by at least one space vehicle (SV);

determine a fraction of a chip associated with at least one carrier signal phase measurement sample; and

determine at least one SV transmit time based, at least in part on a local receiver time, said current chip number, and said fraction of said chip.

24. The article as recited in claim 23, wherein the computer implementable instructions, if implemented by one or more processing units, operatively enable the one or more processing unit to:

determine a carrier phase integer ambiguity associated with at least said at least one SV transmit time.

25. The article as recited in claim 24, wherein the computer implementable instructions, if implemented by one or more processing units, operatively enable the one or more processing unit to:

determine at least one cumulated carrier phase measurement based, at least in part, on said at least one SV transmit time and said carrier phase integer ambiguity.

26. The article as recited in claim 25, wherein the computer implementable instructions, if implemented by one or more processing units, operatively enable the one or more processing unit to:

determine a Double Difference (DD) Carrier Phase observable based, at least in part, on said at least one cumulated carrier phase measurement.

27. The article as recited in claim 26, wherein said DD Carrier Phase observable is associated, at least in part, with at least one other receiver of at least one other device.

28. The article as recited in claim 27, wherein said local receiver is associated with a slave receiver and said at least one other device comprises a master device.

29. The article as recited in claim 28, wherein said slave and master devices are operatively coupled together through at least a portion of a wireless network.

30. The article as recited in claim 28, wherein the computer implementable instructions, if implemented by one or more processing units, operatively enable the one or more processing unit to:

establish said local receiver time based, at least in part, on synchronization information associated with said master device.

31. The article as recited in claim 28, wherein said master device and said at least one SV are substantially synchronized to an SPS system time.

32. The article as recited in claim 26, wherein the computer implementable instructions, if implemented by one or more processing units, operatively enable the one or more processing unit to:

determine a transmit time ambiguity associated with said slave device based, at least in part, on at least one DD Carrier Phase observable; and

resolve a single unknown parameter vector based, at least in part, on a transmit time ambiguity associated with said slave device, and at least one DD integer ambiguity associated with at least said at least one SV.

33. The article as recited in claim 26, wherein the computer implementable instructions, if implemented by one or more processing units, operatively enable the one or more processing unit to:

determine a DD carrier phase linearization point based, at least in part, on said DD carrier phase observable; and

determine a relative position between at least said slave and master devices based, at least in part, on said DD carrier phase linearization point.

34. An apparatus comprising:

a receiver operatively enabled to acquire at least one SPS signal associated with a spread-spectrum sequence as transmitted using a carrier signal by at least one space vehicle (SV); and

at least one processing unit operatively coupled to said receiver, and operatively enabled to;

determine a current chip number associated with said spread-spectrum sequence;

determine a fraction of a chip associated with at least one carrier signal phase measurement sample; and

determine at least one SV transmit time based, at least in part on a local receiver time, said current chip number, and said fraction of said chip.

35. The apparatus as recited in claim 34, wherein said one processing unit is further operatively enabled to:

determine a carrier phase integer ambiguity associated with at least said at least one SV transmit time.

36. The apparatus as recited in claim 35, wherein said one processing unit is further operatively enabled to:

determine at least one cumulated carrier phase measurement based, at least in part, on said at least one SV transmit time and said carrier phase integer ambiguity.

37. The apparatus as recited in claim 36, wherein said one processing unit is further operatively enabled to:

determine a Double Difference (DD) Carrier Phase observable based, at least in part, on said at least one cumulated carrier phase measurement.

38. The apparatus as recited in claim 37, wherein said DD Carrier Phase observable is associated, at least in part, with at least said second device.

39. The apparatus as recited in claim 38, wherein said first device comprises a slave device and said second device comprises a master device.

40. The apparatus as recited in claim 39, wherein said one processing unit is further operatively enabled to:

establish said local receiver time based, at least in part, on synchronization information associated with said master device.

41. The apparatus as recited in claim 39, wherein said master device and said at least one SV are substantially synchronized to an SPS system time.

42. The apparatus as recited in claim 37, wherein said one processing unit is further operatively enabled to:

determine a transmit time ambiguity associated with said slave device based, at least in part, on at least one DD Carrier Phase observable; and

resolve a single unknown parameter vector based, at least in part, on a transmit time ambiguity associated with said slave device, and at least one DD integer ambiguity associated with at least said at least one SV.

43. The apparatus as recited in claim 37, wherein said one processing unit is further operatively enabled to:

determine a DD carrier phase linearization point based, at least in part, on said DD carrier phase observable; and

determine a relative position between at least said slave and master devices based, at least in part, on said DD carrier phase linearization point.