GPS position tracking method with variable updating rate for power conservation

• US 8,131,326 B2
• Filed: 03/15/2010
• Issued: 03/06/2012
• Est. Priority Date: 03/17/2005
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Persico, Charles James
• Primary Examiner(s): Cho, Un C
• Application Number:
  US12/724,220
• Publication Number:
  US 20110070896A1
• Time in Patent Office: 722 Days
• Field of Search: 455/456.1, 455/456.6, 455/574, 342/107, 342/114, 342/357.01, 342/357.06, 342/357.08, 342/357.1, 342/357.12, 342/104, 342/109, 342/457
• US Class Current: 455/574
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 19/39 the satellite radio beacon positioning system transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
• CPC Class Codes: G01S 19/393 Trajectory determination or predictive tracking, e.g. Kalman filtering
• CPC Class Codes: G01S 19/396 Determining accuracy or reliability of position or pseudorange measurements
• CPC Class Codes: G01S 5/0263 by combining or switching between positions derived from two or more separate positioning systems
• CPC Class Codes: G01S 5/0294 Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering

Abstract

A system and method in which the position update rate is adaptively modified, based on previous position measurements. By adjusting the update rate based on velocity predictions from two or more position fixes, a lower update rate may be used without exceeding the maximum error. Lowering the update rate reduces power consumption in the UE, providing longer battery operation. The updating method may comprise periodically repeating the velocity prediction and periodically adjusting the update rate responsive thereto. The update rate may be adjusted using additional information such as an acceleration prediction, a minimum update rate, or a preferred error. In some embodiments a model for user movement may be used to provide more accurate predictions, for example, stationary, walking, jogging, city driving, and freeway driving. The updating method may comprise receiving user input regarding the maximum position error.

Claims

1. A method for efficiently updating the position of mobile wireless user equipment (UE) to reduce the rate of energy consumption, comprising:

establishing an update rate for determining position;

making a velocity prediction for said UE;

adjusting said update rate responsive to said velocity prediction and a target power consumption; and

making a series of position fixes at said adjusted update rate.

2. The method of claim 1, further comprising periodically repeating said velocity prediction and periodically adjusting said update rate responsive thereto.

3. The method of claim 1, further comprising making an acceleration prediction and adjusting said update rate responsive to said acceleration prediction.

4. The method of claim 1, further comprising establishing a minimum update rate and adjusting said update rate to at least said minimum update rate.

5. The method of claim 1, further comprising determining a model for user movement responsive to said series of position fixes, and further adjusting said update rate responsive to said movement model and said velocity prediction.

6. The method of claim 5, wherein said movement model comprises one of stationary, walking, jogging, city driving, and freeway driving.

7. The method of claim 1, further comprising establishing a preferred error and adjusting said update rate responsive to said preferred error and said maximum error.

8. The method of claim 1, further comprising receiving user input regarding a maximum position error and determining said maximum position error responsive thereto.

9. The method of claim 1, wherein said step of making said velocity prediction for said UE comprises:

making a series of at least two position fixes at said update rate;

estimating a distance between at least two of said position fixes;

determining a time difference between said two position fixes; and

responsive to said time difference and said estimated distance, calculating said velocity prediction of said UE.

10. The method of claim 1, wherein said step of adjusting said update rate responsive to said velocity prediction comprises reducing said update rate to reduce power consumption without exceeding a maximum position error.

11. The method of claim 1, wherein said step of adjusting said update rate comprises increasing said update rate to follow a faster predicted velocity without exceeding a maximum position error.

12. A system for efficiently updating the position of mobile wireless user equipment (UE) to reduce the rate of energy consumption, comprising:

means for establishing an update rate for determining position;

means for making a velocity prediction for said UE;

means for adjusting said update rate responsive to said velocity prediction and a target power consumption; and

means for making a series of position fixes at said adjusted update rate.

13. The system of claim 12, further comprising means for periodically repeating said velocity prediction, and means for periodically adjusting said update rate responsive thereto.

14. The system of claim 12, further comprising means for making an acceleration prediction, and means for adjusting said update rate responsive to said acceleration prediction.

15. The system of claim 12, further comprising means for establishing a minimum update rate, and means for adjusting said update rate to at least said minimum update rate.

16. The system of claim 12, further comprising means for determining a model for user movement responsive to said series of position fixes, and means for further adjusting said update rate responsive to said movement model and said velocity prediction.

17. The system of claim 16, wherein said movement model comprises one of stationary, walking, jogging, city driving, and freeway driving.

18. The system of claim 12, further comprising means for establishing a preferred error, and means for adjusting said update rate responsive to said preferred error and said maximum error.

19. The system of claim 12, further comprising means for receiving user input regarding a maximum position error, and means for determining said maximum position error responsive thereto.

20. The system of claim 12, wherein said means for making said velocity prediction for said UE comprises:

means for making a series of at least two position fixes at said update rate;

means for estimating a distance between at least two of said position fixes;

means for determining a time difference between said two position fixes; and

means, responsive to said time difference and said estimated distance, for calculating said velocity prediction of said UE.

21. The system of claim 12, wherein said means for adjusting said update rate responsive to said velocity prediction comprises means for reducing said update rate to reduce power consumption without exceeding a maximum position error.

22. The system of claim 12, wherein said means for adjusting said update rate comprises means for increasing said update rate to follow a faster predicted velocity without exceeding a maximum position error.

23. A method for efficiently updating the position of mobile wireless user equipment (UE) to reduce the rate of energy consumption, comprising:

establishing an update rate for determining position;

making a velocity prediction for said UE;

adjusting said update rate responsive to said velocity prediction and a location of said UE; and

making a series of position fixes at said adjusted update rate.

24. The method of claim 23, further comprising periodically repeating said velocity prediction and periodically adjusting said update rate responsive thereto.

25. The method of claim 23, further comprising making an acceleration prediction and adjusting said update rate responsive to said acceleration prediction.

26. The method of claim 23, further comprising establishing a minimum update rate and adjusting said update rate to at least said minimum update rate.

27. The method of claim 23, further comprising determining a model for user movement responsive to said series of position fixes and further adjusting said update rate responsive to said movement model and said velocity prediction.

28. The method of claim 27, wherein said movement model comprises one of stationary, walking, jogging, city driving, and freeway driving.

29. The method of claim 23, further comprising establishing a preferred error and adjusting said update rate responsive to said preferred error and said maximum error.

30. The method of claim 23, further comprising receiving user input regarding a maximum position error and determining said maximum position error responsive thereto.

31. The method of claim 23, wherein said step of making said velocity prediction for said UE comprises:

making a series of at least two position fixes at said update rate;

estimating a distance between at least two of said position fixes;

determining a time difference between said two position fixes; and

responsive to said time difference and said estimated distance, calculating said velocity prediction of said UE.

32. The method of claim 23, wherein said step of adjusting said update rate responsive to said velocity prediction comprises reducing said update rate to reduce power consumption without exceeding a maximum position error.

33. The method of claim 23, wherein said step of adjusting said update rate comprises increasing said update rate to follow a faster predicted velocity without exceeding a maximum position error.

34. A system for efficiently updating the position of mobile wireless user equipment (UE) to reduce the rate of energy consumption, comprising:

means for establishing an update rate for determining position;

means for making a velocity prediction for said UE;

means for adjusting said update rate responsive to said velocity prediction and a location of said UE; and

means for making a series of position fixes at said adjusted update rate.

35. The system of claim 34, further comprising means for periodically repeating said velocity prediction and means for periodically adjusting said update rate responsive thereto.

36. The system of claim 34, further comprising means for making an acceleration prediction and means for adjusting said update rate responsive to said acceleration prediction.

37. The system of claim 34, further comprising means for establishing a minimum update rate and means for adjusting said update rate to at least said minimum update rate.

38. The system of claim 34, further comprising means for determining a model for user movement responsive to said series of position fixes, and means for further adjusting said update rate responsive to said movement model and said velocity prediction.

39. The system of claim 38, wherein said movement model comprises one of stationary, walking, jogging, city driving, and freeway driving.

40. The system of claim 34, further comprising means for establishing a preferred error, and means for adjusting said update rate responsive to said preferred error and said maximum error.

41. The system of claim 34, further comprising means for receiving user input regarding a maximum position error, and means for determining said maximum position error responsive thereto.

42. The system of claim 34, wherein said means for making said velocity prediction for said UE comprises:

means for making a series of at least two position fixes at said update rate;

means for estimating a distance between at least two of said position fixes;

means for determining a time difference between said two position fixes; and

means, responsive to said time difference and said estimated distance, for calculating said velocity prediction of said UE.

43. The system of claim 34, wherein said means for adjusting said update rate responsive to said velocity prediction comprises means for reducing said update rate to reduce power consumption without exceeding a maximum position error.

44. The system of claim 34, wherein said means for adjusting said update rate comprises means for increasing said update rate to follow a faster predicted velocity without exceeding a maximum position error.

45. Apparatus for updating the position of mobile wireless user equipment (UE), comprising:

processing circuitry configured to establish an update rate for determining position;

the processing circuitry further configured to make a velocity prediction for said UE;

the processing circuitry further configured to adjust said update rate responsive to said velocity prediction and a target power consumption; and

the processing circuitry further configured to make a series of position fixes at said adjusted update rate.

46. The apparatus of claim 45, the processing circuitry further configured to periodically repeat said velocity prediction and periodically adjust said update rate responsive thereto.

47. The apparatus of claim 45, the processing circuitry further configured to make an acceleration prediction and adjust said update rate responsive to said acceleration prediction.

48. The apparatus of claim 45, the processing circuitry further configured to establish a minimum update rate and adjust said update rate to at least said minimum update rate.

49. The apparatus of claim 45, the processing circuitry further configured to determine a model for user movement responsive to said series of position fixes, and further adjust said update rate responsive to said movement model and said velocity prediction.

50. The apparatus of claim 49, wherein said movement model comprises one of stationary, walking, jogging, city driving, and freeway driving.

51. The apparatus of claim 45, the processing circuitry further configured to establish a preferred error and adjust said update rate responsive to said preferred error and said maximum error.

52. The apparatus of claim 45, the processing circuitry further configured to receive user input regarding a maximum position error and determine said maximum position error responsive thereto.

53. The apparatus of claim 45, wherein said processing circuitry that is further configured to make said velocity prediction for said UE comprises:

processing circuitry configured to make a series of at least two position fixes at said update rate;

the processing circuitry further configured to estimate a distance between at least two of said position fixes;

the processing circuitry further configured to determine a time difference between said two position fixes; and

the processing circuitry further configured to calculate said velocity prediction of said UE, responsive to said time difference and said estimated distance.

54. The apparatus of claim 45, wherein said processing circuitry that is further configured to adjust said update rate responsive to said velocity prediction comprises processing circuitry configured to reduce said update rate to reduce power consumption without exceeding a maximum position error.

55. The apparatus of claim 45, wherein said processing circuitry that is further configured to adjust said update rate comprises processing circuitry configured to increase said update rate to follow a faster predicted velocity without exceeding a maximum position error.

56. A non-transitory processor-readable storage medium storing a program that when executed on a processor of a device, causes the processor to perform a method of updating the position of mobile wireless user equipment (UE), the method comprising:

establishing an update rate for determining position;

making a velocity prediction for said UE;

adjusting said update rate responsive to said velocity prediction and a target power consumption; and

making a series of position fixes at said adjusted update rate.

57. Apparatus for updating the position of mobile wireless user equipment (UE), comprising:

processing circuitry configured to establish an update rate for determining position;

the processing circuitry further configured to make a velocity prediction for said UE;

the processing circuitry further configured to adjust said update rate responsive to said velocity prediction and a location of said UE; and

the processing circuitry further configured to make a series of position fixes at said adjusted update rate.

58. The apparatus of claim 57, the processing circuitry further configured to periodically repeat said velocity prediction and periodically adjust said update rate responsive thereto.

59. The apparatus of claim 57, the processing circuitry further configured to make an acceleration prediction and adjust said update rate responsive to said acceleration prediction.

60. The apparatus of claim 57, the processing circuitry further configured to establish a minimum update rate and adjust said update rate to at least said minimum update rate.

61. The apparatus of claim 57, the processing circuitry further configured to determine a model for user movement responsive to said series of position fixes, and further adjust said update rate responsive to said movement model and said velocity prediction.

62. The apparatus of claim 61, wherein said movement model comprises one of stationary, walking, jogging, city driving, and freeway driving.

63. The apparatus of claim 57, the processing circuitry further configured to establish a preferred error and adjust said update rate responsive to said preferred error and said maximum error.

64. The apparatus of claim 57, the processing circuitry further configured to receive user input regarding a maximum position error and determine said maximum position error responsive thereto.

65. The apparatus of claim 57, wherein said processing circuitry that is further configured to make said velocity prediction for said UE comprises:

processing circuitry configured to make a series of at least two position fixes at said update rate;

the processing circuitry further configured to estimate a distance between at least two of said position fixes;

the processing circuitry further configured to determine a time difference between said two position fixes; and

the processing circuitry further configured to calculate said velocity prediction of said UE, responsive to said time difference and said estimated distance.

66. The apparatus of claim 57, wherein said processing circuitry that is further configured to adjust said update rate responsive to said velocity prediction comprises processing circuitry configured to reduce said update rate to reduce power consumption without exceeding a maximum position error.

67. The apparatus of claim 57, wherein said processing circuitry that is further configured to adjust said update rate comprises processing circuitry configured to increase said update rate to follow a faster predicted velocity without exceeding a maximum position error.

68. A non-transitory processor-readable storage medium storing a program that when executed on a processor of a device, causes the processor to perform a method of updating the position of mobile wireless user equipment (UE), the method comprising:

establishing an update rate for determining position;

making a velocity prediction for said UE;

adjusting said update rate responsive to said velocity prediction and a location of said UE; and

making a series of position fixes at said adjusted update rate.