Reference Oscillator Management for Wireless Devices Having Position Determination Functionality

• US 20130295865A1
• Filed: 07/01/2013
• Published: 11/07/2013
• Est. Priority Date: 06/18/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: FARMER, Dominic Gerard, BHATIA, Ashok, SIMIC, Emilija M., RISTIC, Borislav
• Granted Patent: US 9,103,915 B2
• Time in Patent Office: Days
• US Class Current: 455/257
• CPC Class Codes: G01S 19/45 by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement
• CPC Class Codes: H03J 1/0008 using a central processing unit, e.g. a microprocessor digital tuning in general H03J5/0245
• CPC Class Codes: H03J 7/02 Automatic frequency control H03J7/18 takes precedence
• CPC Class Codes: H03L 7/00 Automatic control of frequency or phase; Synchronisation
• CPC Class Codes: H04B 1/26 for superheterodyne receivers multiple frequency-changing H03D7/16
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]

Abstract

A method and device for managing a reference oscillator within a wireless device is presented. The method includes selecting reference oscillator parameters associated with the lowest reference oscillator error, where the selection is based upon reference oscillator parameters derived using different technologies within a wireless device, acquiring a satellite based upon the selected reference parameters, determining the quality of the satellite-based position fix, and updating the reference oscillator parameters based upon the quality of the satellite-based position fix. The wireless device includes a wireless communications system, a satellite positioning system (SPS) receiver, a reference oscillator connected to the wireless communications system and SPS receiver, and a mobile controller connected to the reference oscillator, SPS, and wireless communications system, and a memory connected to the mobile controller, where the memory stores a reference oscillator parameter table and instructions causing the mobile controller to execute the aforementioned method.

Claims

1. A method for managing a reference oscillator within a wireless device, comprising:

selecting reference oscillator parameters associated with the lowest reference oscillator error, wherein the selection is based upon reference oscillator parameters derived using different technologies within the wireless device;

acquiring a satellite based upon the selected reference oscillator parameters;

calculating a satellite-based position fix;

determining the quality of the satellite-based position fix, wherein the quality corresponds to an uncertainty associated with the selected reference oscillator parameters; and

updating the reference oscillator parameters based upon the quality of the satellite-based position fix.

2. The method according to claim 1, wherein the reference oscillator comprises a tunable reference oscillator or a free-running reference oscillator, and the reference oscillator parameters include tunable oscillator parameters or free-running reference oscillator parameters, the method further comprising:

determining the frequency center and width of a search window using the frequency oscillator parameters; and

initializing or re-initializing an SPS receiver using the frequency center and search width.

3. The method according to claim 2, wherein the tunable reference oscillator comprises a Voltage Controlled Crystal Oscillator (VCXO) or Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO), and further wherein the free running reference oscillator comprises a crystal oscillator (XO) or a Temperature Compensated Crystal Oscillator (TCXO).

4. The method according to claim 2, further comprising:

determining reference oscillator parameters based upon the quality of satellite-based position fix; and

storing the reference oscillator parameters when the wireless device successfully determines a position fix.

5. The method according to claim 4, wherein the reference oscillator parameters include a reference oscillator frequency bias, reference oscillator frequency bias uncertainty and a time at the reference oscillator parameters were determined

6. The method according to claim 5, wherein the reference oscillator parameters include a reference oscillator frequency control value.

7. The method according to claim 4, further comprising storing the reference oscillator parameters in a table containing a plurality of reference oscillator parameters derived from the various technologies in the wireless device.

8. The method according to claim 4, further comprising:

determining the frequency center and a search window width using the reference oscillator parameters; and

initializing or re-initializing at least one receiver in the wireless device using the frequency center and search window width.

9. The method according to claim 1, wherein the technologies include a communications system and a Satellite Positioning System.

10. The method according to claim 9, wherein the communication network includes at least one of a CDMA network, a TDMA network, and a Wi-Fi network.

11. The method according to claim 9, wherein the Satellite Positioning System include a Global Positioning System (GPS).

12. The method according to claim 1, wherein the reference oscillator comprises a tunable reference oscillator and the reference oscillator parameters include tunable reference oscillator parameters, the method further comprising:

determining the frequency center and a search window width using the reference oscillator parameters; and

tuning a tunable reference oscillator using the determined tunable reference oscillator parameters.

13. The method according to claim 12, wherein the tunable reference oscillator includes a Voltage Controlled Crystal Oscillator (VCXO) or Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO).

14. The method according to claim 12, further comprising:

determining the reference oscillator parameters based upon the quality of the satellite-based position fix; and

storing the reference oscillator parameters when the wireless device successfully determines the satellite-based position fix.

15. The method according to claim 14, wherein the reference oscillator parameters include a reference oscillator frequency control value, reference oscillator frequency bias, reference oscillator frequency bias uncertainty and a time at which the reference oscillator parameters were determined.

16. The method according to claim 15, further comprising

storing the reference oscillator parameters in a table containing a plurality of reference oscillator parameters derived from the various technologies in the wireless device.

17. The method according to claim 16, further comprising:

determining a frequency center and a search window width using the reference oscillator parameters; and

initializing or re-initializing at least one receiver associated with any of the various technologies in the wireless device, using the frequency center and the search window width.

18. The method according to claim 12, wherein the various technologies include a communications system and a Satellite Positioning System.

19. The method according to claim 18, wherein the communication system includes at least one of a CDMA network, a TDMA network, and a Wi-Fi network.

20. The method according to claim 18, wherein the Satellite Positioning System include a Global Positioning System (GPS).

21. The method according to claim 15, further comprising:

receiving a current reference oscillator frequency control value and a current reference oscillator frequency bias estimate;

adjusting the received reference oscillator frequency bias estimate;

performing sanity checks on the adjusted reference oscillator frequency bias estimate; and

determining reference oscillator parameters for storage based upon the adjusted reference oscillator frequency bias parameters.

22. The method according to claim 21, further comprising:

incrementing a counter which represents a confidence in the determined reference oscillator parameters.

23. The method according to claim 22, further comprising:

adjusting the received frequency bias estimate when the stored reference oscillator parameters have been determined and the confidence is sufficient; and

determining a reference oscillator frequency uncertainty based upon an age of the bias estimate.

24. The method of claim 23, further comprising:

resetting the current reference oscillator frequency bias estimate to zero and the current reference oscillator frequency uncertainty to maximum value when the stored reference oscillator parameters have not been initialized or when the confidence is not sufficient.

48. The device according to claim 2, further comprising:

means for determining reference oscillator parameters based upon the quality of satellite-based position fix; and

means for storing the reference oscillator parameters when the wireless device successfully determines a position fix.

49. The device according to claim 48, wherein the reference oscillator parameters include a reference oscillator frequency bias, reference oscillator frequency bias uncertainty and a time at the reference oscillator parameters were determined

50. The device according to claim 49, wherein the reference oscillator parameters include a reference oscillator frequency control value.

51. The device according to claim 48, further comprising means for storing the reference oscillator parameters in a table containing a plurality of reference oscillator parameters derived from the various technologies in the wireless device.

52. The device according to claim 48, further comprising:

means for determining the frequency center and a search window width using the reference oscillator parameters; and

means for initializing or re-initializing at least one receiver in the wireless device using the frequency center and search window width.

60. The device according to claim 15, further comprising means for storing the reference oscillator parameters in a table containing a plurality of reference oscillator parameters derived from the various technologies in the wireless device.

61. The device according to claim 60, further comprising:

means for determining a frequency center and a search window width using the reference oscillator parameters; and

means for initializing or re-initializing at least one receiver associated with any of the various technologies in the wireless device, using the frequency center and the search window width.

65. The device according to claim 60, further comprising:

means for receiving a current reference oscillator frequency control value and a current reference oscillator frequency bias estimate;

means for adjusting the received reference oscillator frequency bias estimate;

means for performing sanity checks on the adjusted reference oscillator frequency bias estimate; and

means for determining reference oscillator parameters for storage based upon the adjusted reference oscillator frequency bias parameters.

66. The device according to claim 65, further comprising:

means for incrementing a counter which represents a confidence in the determined reference oscillator parameters.

67. The device according to claim 66, further comprising:

means for adjusting the received frequency bias estimate when the reference oscillator parameters have been determined and the confidence is sufficient; and

means for determining a reference oscillator frequency uncertainty based upon an age of the bias estimate.

68. The device of claim 67, further comprising:

means for resetting the current reference oscillator frequency bias estimate to zero and the reference oscillator frequency uncertainty to maximum value when the reference oscillator parameters have not been initialized or when the confidence is not sufficient.

25. A wireless device having position determination functionality which manages a reference oscillator using a plurality of technologies, comprising:

a wireless communications system;

a satellite positioning system (SPS) receiver;

a reference oscillator connected to the wireless communications system and SPS receiver; and

a mobile controller connected to the reference oscillator, SPS, and wireless communications system; and

a memory connected to the mobile controller, wherein the memory stores a reference oscillator parameter table and instructions causing the mobile controller to;

select reference oscillator parameters associated with the lowest reference oscillator error, wherein the selection is based upon reference oscillator parameters derived using different technologies within a wireless device,

acquire a satellite based upon the selected reference oscillator parameters,

calculate a satellite-based position fix,

determine the quality of the satellite-based position fix, wherein the quality corresponds to an uncertainty associated with the selected reference oscillator parameters, and

update the reference parameters based upon the quality of the satellite-based position fix.

26. The device according to claim 25, wherein the reference oscillator comprises either a tunable reference oscillator or a free-running reference oscillator, and the reference oscillator parameters include tunable reference oscillator parameters or free-running reference oscillator parameters, and further wherein the stored instructions cause the processor to:

determine the frequency center and width of a search window using the reference oscillator parameters; and

initialize the SPS receiver using the frequency center and search width.

27. The device according to claim 26, wherein the tunable reference oscillator includes a Voltage Controlled Crystal Oscillator (VCXO) or Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO), and/or the free running reference oscillator includes a crystal oscillator (XO) or a Temperature Compensated Crystal Oscillator (TCXO).

28. The device according to claim 26, wherein the stored instructions further cause the processor to:

determine reference oscillator parameters based upon the quality of position fix and

store the reference oscillator parameters when the wireless device successfully determines its position.

29. The device according to claim 28, wherein the reference oscillator parameters include a reference oscillator frequency bias, reference oscillator frequency uncertainty and a time at which the reference oscillator parameters are determined.

30. The device according to claim 25, wherein the reference oscillator parameters include a reference oscillator frequency control value.

31. The device according to claim 29, wherein the stored instructions further cause the processor to store the reference oscillator parameters in a table containing a plurality of reference oscillator parameters derived from the various technologies the wireless device.

32. The device according to claim 25, wherein the stored instructions cause the processor to:

determine a frequency center and width of a search window using the reference oscillator parameters; and

initialize or re-initialize at least one receiver associated with any of the various technologies in the wireless device, using the frequency center and search window width.

33. The device according to claim 25, wherein the various technologies are associated with the wireless communications system and a SPS receiver.

34. The device according to claim 33, wherein the wireless communication system includes at least one of a CDMA system, a TDMA system, and a Wi-Fi system.

35. The device according to claim 33, wherein the SPS receiver includes a Global Positioning System (GPS) receiver

36. The device according to claim 25, wherein the reference oscillator comprises a tunable oscillator, and the reference oscillator parameters include tunable reference oscillator parameters, further wherein the stored instructions cause the processor to:

determine the frequency center and width of the search window based upon the reference oscillator parameters; and

adjust the tunable oscillator using the determined reference oscillator parameters.

37. The device according to claim 36, wherein the tunable oscillator includes a Voltage Controlled Crystal Oscillator (VCXO) or a Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO).

38. The device according to claim 36, wherein the stored instructions further cause the processor to:

determine reference oscillator parameters based upon the quality of position fix; and

store the reference oscillator parameters when the wireless device successfully calculates its position.

39. The device according to claim 38, wherein the reference oscillator parameters include a reference oscillator frequency control value, reference oscillator frequency bias, reference oscillator frequency bias uncertainty and a time at which determined

40. The device according to claim 39, wherein the reference oscillator parameter table stores a plurality of reference oscillator parameters derived from various technologies.

41. The device according to claim 40, wherein the stored instructions cause the processor to:

determine a frequency center and a search window width using the reference oscillator parameters; and

initialize or re-initialize at least one receiver associated with any of the various technologies in the wireless device, using the frequency center and the search window width.

42. The device according to claim 31, wherein the various technologies are associated with the wireless communications system and a SPS receiver.

43. The device according to claim 42, wherein the wireless communication system includes at least one of a CDMA system, a TDMA system, and a Wi-Fi system.

44. The device according to claim 43, wherein the SPS receiver includes a Global Positioning System (GPS) receiver.

45. A wireless device having position determination functionality which manages a reference oscillator using a plurality of technologies, comprising:

means for selecting reference oscillator parameters associated with the lowest reference oscillator error, wherein the selection is based upon reference oscillator parameters derived using different technologies within the wireless device;

means for acquiring a satellite based upon the selected reference oscillator parameters;

means for calculating a satellite-based position fix;

means for determining the quality of the satellite-based position fix, wherein the quality corresponds to an uncertainty associated with the selected reference oscillator parameters; and

means for updating the reference oscillator parameters based upon the quality of the satellite-based position fix.

46. The device according to claim 45, wherein the reference oscillator comprises a tunable reference oscillator or a free-running reference oscillator, and the reference oscillator parameters include tunable oscillator parameters or free-running reference oscillator parameters, the device further comprising:

means for determining the frequency center and width of a search window using the frequency oscillator parameters; and

means for initializing or re-initializing an SPS receiver using the frequency center and search width.

47. The device according to claim 46, wherein the tunable reference oscillator comprises a Voltage Controlled Crystal Oscillator (VCXO) or Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO), and further wherein the free running reference oscillator comprises a crystal oscillator (XO) or a Temperature Compensated Crystal Oscillator (TCXO).

53. The device according to claim 45, wherein the technologies include a communications system and a Satellite Positioning System.

54. The device according to claim 53, wherein the communication network includes at least one of a CDMA network, a TDMA network, and a Wi-Fi network.

55. The device according to claim 53, wherein the Satellite Positioning System include a Global Positioning System (GPS).

56. The device according to claim 45, wherein the reference oscillator comprises a tunable reference oscillator and the reference oscillator parameters include tunable reference oscillator parameters, the device further comprising:

means for determining the frequency center and a search window width using the reference oscillator parameters; and

means for tuning a tunable reference oscillator using the determined tunable reference oscillator parameters.

57. The device according to claim 56, wherein the tunable reference oscillator includes a Voltage Controlled Crystal Oscillator (VCXO) or Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO).

58. The device according to claim 56, further comprising:

means for determining the reference oscillator parameters based upon the quality of the satellite-based position fix; and

means for storing the reference oscillator parameters when the wireless device successfully determines the satellite-based position fix.

59. The device according to claim 58, wherein the reference oscillator parameters include a reference oscillator frequency control value, reference oscillator frequency bias, reference oscillator frequency bias uncertainty and a time at which the reference oscillator parameters were determined.

62. The device according to claim 56, wherein the various technologies include a communications system and a Satellite Positioning System.

63. The device according to claim 62, wherein the communication system includes at least one of a CDMA network, a TDMA network, and a Wi-Fi network.

64. The device according to claim 62, wherein the Satellite Positioning System include a Global Positioning System (GPS).

69. A non-transitory computer readable medium comprising instructions for causing a processor to perform operations, comprising:

instructions to select reference oscillator parameters associated with the lowest reference oscillator error, wherein the selection is based upon reference oscillator parameters derived using different technologies within the wireless device;

instructions to acquire a satellite based upon the selected reference oscillator parameters;

instructions to calculate a satellite-based position fix;

instructions to determine the quality of the satellite-based position fix, wherein the quality corresponds to an uncertainty associated with the reference oscillator parameters; and

instructions to update the reference oscillator parameters based upon the quality of the satellite-based position fix.

70. The non-transitory computer readable medium according to claim 69, wherein the reference oscillator comprises a tunable reference oscillator or a free-running reference oscillator, and the reference oscillator parameters include tunable oscillator parameters or free-running reference oscillator parameters, the non-transitory computer readable medium further comprising:

instructions to determine the frequency center and width of a search window using the frequency oscillator parameters; and

instructions to initialize or re-initializing an SPS receiver using the frequency center and search width.

71. The non-transitory computer readable medium according to claim 70, wherein the tunable reference oscillator comprises a Voltage Controlled Crystal Oscillator (VCXO) or Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO), and further wherein the free running reference oscillator comprises a crystal oscillator (XO) or a Temperature Compensated Crystal Oscillator (TCXO).

72. The non-transitory computer readable medium according to claim 70, further comprising:

instructions to determine reference oscillator parameters based upon the quality of satellite-based position fix; and

instructions to store the reference oscillator parameters when the wireless device successfully determines a position fix.

73. The non-transitory computer readable medium according to claim 72, wherein the reference oscillator parameters include a reference oscillator frequency bias, reference oscillator frequency bias uncertainty and a time at the reference oscillator parameters were determined.

74. The non-transitory computer readable medium according to claim 73, wherein the reference oscillator parameters include a reference oscillator frequency control value.

75. The non-transitory computer readable medium according to claim 72, further comprising instructions to store the reference oscillator parameters in a table containing a plurality of reference oscillator parameters derived from the various technologies in the wireless device.

76. The non-transitory computer readable medium according to claim 72, further comprising:

instructions to determine the frequency center and a search window width using the reference oscillator parameters; and

instructions to initialize or re-initializing at least one receiver in the wireless device using the frequency center and search window width.

77. The non-transitory computer readable medium according to claim 69, wherein the technologies include a communications system and a Satellite Positioning System.

78. The non-transitory computer readable medium according to claim 77, wherein the communication network includes at least one of a CDMA network, a TDMA network, and a Wi-Fi network.

79. The non-transitory computer readable medium according to claim 77, wherein the Satellite Positioning System include a Global Positioning System (GPS).

80. The non-transitory computer readable medium according to claim 69, wherein the reference oscillator comprises a tunable reference oscillator and the reference oscillator parameters include tunable reference oscillator parameters, the non-transitory computer readable medium further comprising:

instructions to determine the frequency center and a search window width using the reference oscillator parameters; and

instructions to tune a tunable reference oscillator using the determined tunable reference oscillator parameters.

81. The non-transitory computer readable medium according to claim 80, wherein the tunable reference oscillator includes a Voltage Controlled Crystal Oscillator (VCXO) or Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO).

82. The non-transitory computer readable medium according to claim 80, further comprising:

instructions to determine the reference oscillator parameters based upon the quality of the satellite-based position fix; and

instructions to store the reference oscillator parameters when the wireless device successfully determines the satellite-based position fix.

83. The non-transitory computer readable medium according to claim 82, wherein the reference oscillator parameters include a reference oscillator frequency control value, reference oscillator frequency bias, reference oscillator frequency bias uncertainty and a time at which the reference oscillator parameters were determined

84. The non-transitory computer readable medium according to claim 83, further comprising

instructions to store the reference oscillator parameters in a table containing a plurality of reference oscillator parameters derived from the various technologies in the wireless device.

85. The non-transitory computer readable medium according to claim 84, further comprising:

instructions to determine a frequency center and a search window width using the reference oscillator parameters; and

instructions to initialize or re-initialize at least one receiver associated with any of the various technologies in the wireless device, using the frequency center and the search window width.

86. The non-transitory computer readable medium according to claim 80, wherein the various technologies include a communications system and a Satellite Positioning System.

87. The non-transitory computer readable medium according to claim 86, wherein the communication system includes at least one of a CDMA network, a TDMA network, and a Wi-Fi network.

88. The non-transitory computer readable medium according to claim 86, wherein the Satellite Positioning System include a Global Positioning System (GPS).

89. The non-transitory computer readable medium according to claim 83, further comprising:

instructions to receive a current reference oscillator frequency control value and a current reference oscillator frequency bias estimate;

instructions to adjust the received reference oscillator frequency bias estimate;

instructions to perform sanity checks on the adjusted reference oscillator frequency bias estimate; and

instructions to determine reference oscillator parameters for storage based upon the adjusted reference oscillator frequency bias parameters.

90. The non-transitory computer readable medium according to claim 89, further comprising:

instructions to increment a counter which represents a confidence in the determined reference oscillator parameters.

91. The non-transitory computer readable medium according to claim 90, further comprising:

instructions to adjust the received frequency bias estimate when the reference oscillator parameters have been determined and the confidence is sufficient; and

instructions to determine a reference oscillator frequency uncertainty based upon an age of the bias estimate.

92. The non-transitory computer readable medium of claim 91, further comprising:

instructions to reset the current reference oscillator frequency bias estimate to zero and the reference oscillator frequency uncertainty to maximum value when the reference oscillator parameters have not been initialized or when the confidence is not sufficient.