Detection and filtering of an undesired narrowband signal contribution in a wireless signal receiver

• US 9,008,249 B2
• Filed: 02/10/2012
• Issued: 04/14/2015
• Est. Priority Date: 02/10/2012
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Wu, Jie, Simic, Emilija M., Pals, Timothy Paul, Hoang, Duong A.
• Primary Examiner(s): Washburn, Daniel
• Assistant Examiner(s): Singh, Amneet
• Application Number:
  US13/371,311
• Publication Number:
  US 20130208838A1
• Time in Patent Office: 1,159 Days
• Field of Search: 375/350, 375/148, 375/150, 375/347, 455/307, 708/300, 342/357, 370/210
• US Class Current: 375/350
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
• CPC Class Codes: H04B 1/1036 with automatic suppression of narrow band noise or interference, e.g. by using tuneable notch filters H04B1/123 takes precedence; filter circuits H03H

Abstract

Techniques are provided which may be implemented using various methods and/or apparatuses in a device comprising a receiver to scan a spectral band of a received signal comprising a desired signal contribution to determine whether signal data associated with at least a sub-band of the spectral band further comprises at least one undesired signal contribution. In response to determining that the signal data comprises at least one undesired signal contribution, the mobile station may initiate at least one notch filter to affect the undesired signal contribution in subsequent signal data associated with the received signal.

Claims

1. A method comprising, at a device comprising a receiver:

scanning at least one sub-band of a plurality of sub-bands within a spectral band of a received signal comprising a desired signal contribution to determine whether signal data obtained from said at least one sub-band further comprises at least one undesired signal contribution, wherein said at least one sub-band is selected for scanning based, at least in part, on a scan order that prioritizes scanning of said plurality of sub-bands based, at least in part, on;

a ranking in increasing order of differences between a center frequency of said spectral band and respective center frequencies of each of said plurality of sub-bands, wherein said respective center frequencies of a first portion of said plurality of sub-bands are greater than said center frequency of said spectral band, and said respective center frequencies of a second portion of said plurality of sub-bands are less than said center frequency of said spectral band, and wherein at least a part of said ranking in increasing order alternates between sub-bands of said first portion and sub-bands of said second portion; and

in response to determining that said signal data in said at least one sub-band comprises said at least one undesired signal contribution, initiating at least one notch filter within the receiver to affect said at least one undesired signal contribution.

2. The method as recited in claim 1, wherein said scanning further comprises setting:

a bandwidth of one or more of said plurality of sub-bands;

a center frequency of one or more of said plurality of sub-bands;

an integration time for one or more of said plurality of sub-bands;

or a combination thereof.

3. The method as recited in claim 1, wherein said scanning further comprises:

selecting said at least one sub-band; and

estimating a center frequency for said at least one undesired signal contribution.

4. The method as recited in claim 3, wherein said scanning further comprises:

selecting said at least one sub-band;

collecting signal samples in said selected sub-band;

applying Fourier analysis to said signal samples to generate a power spectrum for said selected sub-band; and

applying peak processing to said power spectrum to estimate one or more parameters for said at least one undesired signal contribution in said selected sub-band.

5. The method as recited in claim 3, wherein said estimating said center frequency further comprises:

non-coherently combining one or more power spectra for said at least one sub-band; and

applying a threshold to said combined power spectra.

6. The method as recited in claim 1, wherein two of said plurality of sub-bands are at least partially overlapping.

7. The method as recited in claim 1, wherein at least two of said plurality of sub-bands have different center frequencies and equal bandwidth sizes.

8. The method as recited in claim 1, wherein said spectral band is consumed by said plurality of sub-bands.

9. The method as recited in claim 1, and further comprising, at said device:

obtaining said signal data from at least one of a plurality of different processing stages in said receiver.

10. The method as recited in claim 1, wherein said signal data is obtained either before or after a filtering stage comprising said at least one notch filter.

11. The method as recited in claim 1, wherein said desired signal contribution comprises a satellite positioning system (SPS) signal.

12. The method as recited in claim 1, wherein said at least one undesired signal contribution comprises a continuous wave signal that interferes with said desired signal.

13. The method as recited in claim 1, wherein said scanning is initiated in response to one or more triggering events.

14. The method as recited in claim 13, wherein said one or more triggering events comprises at least one of:

a device or session initiation event;

an new channel initiation event;

a time-based event;

a frequency drift event;

an initiated scan event;

or a signal data threshold event.

15. The method as recited in claim 1, and further comprising, at said device:

determining at least one parameter for said at least one undesired signal contribution.

16. The method as recited in claim 15, wherein said at least one parameter is indicative of at least one of:

an estimated power, an estimated bandwidth, or an estimated center frequency for said at least one undesired signal contribution.

17. The method as recited in claim 15, and further comprising, at said device:

storing said at least one parameter in memory; and

subsequently programming said at least one notch filter based, at least in part, on said stored parameter.

18. The method as recited in claim 15, and further comprising, at said device:

transmitting said at least one parameter to at least one other device.

19. The method as recited in claim 18, and further comprising, at said device:

transmitting a current estimated position of said device to said at least one other device.

20. An apparatus comprising:

means for scanning at least one sub-band of a plurality of sub-bands within a spectral band of a received signal comprising a desired signal contribution to determine whether signal data obtained from said at least one sub-band further comprises at least one undesired signal contribution, wherein said at least one sub-band is selected for scanning based, at least in part, on a scan order that prioritizes scanning of said plurality of sub-bands based, at least in part, on;

a ranking in increasing order of differences between a center frequency of said spectral band and respective center frequencies of each of said plurality of sub-bands, wherein said respective center frequencies of a first portion of said plurality of sub-bands are greater than said center frequency of said spectral band, and said respective center frequencies of a second portion of said plurality of sub-bands are less than said center frequency of said spectral band, and wherein at least a part of said ranking in increasing order alternates between sub-bands of said first portion and sub-bands of said second portion; and

means for initiating at least one notch filter within a receiver to affect said at least one undesired signal contribution, in response to determining that said signal data in said at least one sub-band comprises said at least one undesired signal contribution.

21. The apparatus as recited in claim 20, and further comprising at least one of:

means for setting a bandwidth of one or more of said plurality of sub-bands;

means for setting a center frequency of one or more of said plurality of sub-bands;

or

means for setting an integration time for one or more of said plurality of sub-bands.

22. The apparatus as recited in claim 20, wherein said means for scanning further comprises:

means for selecting said at least one sub-band; and

means for estimating a center frequency for said at least one undesired signal contribution.

23. The apparatus as recited in claim 22, wherein said estimating said center frequency further comprises:

non-coherently combining one or more power spectra for said at least one sub-band; and

applying a threshold to said combined power spectra.

24. The apparatus as recited in claim 20, wherein said scanning further comprises:

means for selecting said at least one sub-band;

means for collecting signal samples in said selected sub-band;

means for applying Fourier analysis to said signal samples to generate a power spectrum for said selected sub-band; and

means for applying peak processing to said power spectrum to estimate one or more parameters for said at least one undesired signal contribution in said selected sub-band.

25. The apparatus as recited in claim 20, wherein two of said plurality of sub-bands are at least partially overlapping.

26. The apparatus as recited in claim 20, wherein at least two of said plurality of sub-bands have different center frequencies and equal bandwidth sizes.

27. The apparatus as recited in claim 20, wherein said spectral band is consumed by said plurality of sub-bands.

28. The apparatus as recited in claim 20, and further comprising:

means for obtaining said signal data from at least one of a plurality of different processing stages in said receiver.

29. The apparatus as recited in claim 20, wherein said desired signal contribution comprises a SPS signal.

30. The apparatus as recited in claim 20, wherein said at least one undesired signal contribution comprises a continuous wave signal that interferes with said desired signal.

31. The apparatus as recited in claim 20, wherein said scanning is initiated in response to one or more triggering events.

32. The apparatus as recited in claim 31, wherein said one or more triggering events comprises at least one of:

a device or session initiation event;

an new channel initiation event;

a time-based event;

a frequency drift event;

an initiated scan event;

or a signal data threshold event.

33. The apparatus as recited in claim 20, and further comprising:

means for determining at least one parameter for said at least one undesired signal contribution.

34. The apparatus as recited in claim 33, wherein said at least one parameter is indicative of at least one of:

an estimated power, an estimated bandwidth, or an estimated center frequency for said at least one undesired signal contribution.

35. The apparatus as recited in claim 33, and further comprising:

means for storing said at least one parameter in memory; and

means for subsequently programming said at least one notch filter based, at least in part, on said stored parameter.

36. The apparatus as recited in claim 33, and further comprising:

means for transmitting said at least one parameter to at least one other device.

37. A device comprising:

a receiver; and

at least one processing unit to;

scan at least one sub-band of a plurality of sub-bands within a spectral band of a signal received via said receiver, said received signal comprising a desired signal contribution to determine whether signal data obtained from said at least one sub-band further comprises at least one undesired signal contribution, wherein said at least one sub-band is selected for scanning based, at least in part, on a scan order that prioritizes scanning of said plurality of sub-bands based, at least in part, on;

a ranking in increasing order of differences between a center frequency of said spectral band and respective center frequencies of each of said plurality of sub-bands, wherein said respective center frequencies of a first portion of said plurality of sub-bands are greater than said center frequency of said spectral band, and said respective center frequencies of a second portion of said plurality of sub-bands are less than said center frequency of said spectral band, and wherein at least a part of said ranking in increasing order alternates between sub-bands of said first portion and sub-bands of said second portion; and

in response to determining that said signal data in said at least one sub-band comprises said at least one undesired signal contribution, initiate at least one notch filter within said receiver to affect said at least one undesired signal contribution.

38. The device as recited in claim 37, said at least one processing unit to further set:

a bandwidth of one or more of said plurality of sub-bands;

a center frequency of one or more of said plurality of sub-bands;

an integration time for one or more of said plurality of sub-bands;

or

a combination thereof.

39. The device as recited in claim 37, said at least one processing unit to further:

select said at least one sub-band; and

estimate a center frequency for said at least one undesired signal contribution.

40. The device as recited in claim 39, said at least one processing unit to further:

select said at least one sub-band;

collect signal samples in said selected sub-band;

apply Fourier analysis to said signal samples to generate a power spectrum for said selected sub-band; and

apply peak processing to said power spectrum to estimate one or more parameters for said at least one undesired signal contribution in said selected sub-band.

41. The device as recited in claim 39, said at least one processing unit to further:

non-coherently combine one or more power spectra for said at least one sub-band; and

apply a threshold to said combined power spectra.

42. The device as recited in claim 37, wherein two of said plurality of sub-bands are at least partially overlapping.

43. The device as recited in claim 37, wherein at least two of said plurality of sub-bands have different center frequencies and equal bandwidth sizes.

44. The device as recited in claim 37, wherein said spectral band is consumed by said plurality of sub-bands.

45. The device as recited in claim 37, said at least one processing unit to further:

obtain said signal data from at least one of a plurality of different processing stages in said receiver.

46. The device as recited in claim 37, wherein said signal data is obtained either before or after a filtering stage comprising said at least one notch filter.

47. The device as recited in claim 37, wherein said desired signal contribution comprises a SPS signal.

48. The device as recited in claim 37, wherein said at least one undesired signal contribution comprises a continuous wave signal that interferes with said desired signal.

49. The device as recited in claim 37, said at least one processing unit to further:

initiate said scan in response to one or more triggering events.

50. The device as recited in claim 49, wherein said one or more triggering events comprises at least one of:

a device or session initiation event;

an new channel initiation event;

a time-based event;

a frequency drift event;

an initiated scan event;

or a signal data threshold event.

51. The device as recited in claim 37, said at least one processing unit to further:

determine at least one parameter for said at least one undesired signal contribution.

52. The device as recited in claim 51, wherein said at least one parameter is indicative of at least one of:

an estimated power, an estimated bandwidth, or an estimated center frequency for said at least one undesired signal contribution.

53. The device as recited in claim 51, and further comprising:

memory; and

wherein said at least one processing unit to further;

initiate storage of said at least one parameter in said memory; and

subsequently program said at least one notch filter based, at least in part, on said stored parameter.

54. The device as recited in claim 51, and further comprising:

a communication interface; and

wherein said at least one processing unit to further;

initiate transmission of said at least one parameter to at least one other device via said communication interface.

55. The device as recited in claim 54, said at least one processing unit to further:

initiate transmission of a current estimated position of said device to said at least one other device via said communication interface.

56. An article for use in a device comprising a receiver and a processing unit, the article comprising:

a non-transitory computer readable medium having stored therein computer-implementable instructions executable by said processing unit to;

scan at least one sub-band of a plurality of sub-bands within a spectral band of a received signal comprising a desired signal contribution to determine whether signal data obtained from said at least one sub-band further comprises at least one undesired signal contribution, wherein said at least one sub-band is selected for scanning based, at least in part, on a scan order that prioritizes scanning of said plurality of sub-bands based, at least in part, on;

a ranking in increasing order of differences between a center frequency of said spectral band and respective center frequencies of each of said plurality of sub-bands, wherein said respective center frequencies of a first portion of said plurality of sub-bands are greater than said center frequency of said spectral band, and said respective center frequencies of a second portion of said plurality of sub-bands are less than said center frequency of said spectral band, and wherein at least a part of said ranking in increasing order alternates between sub-bands of said first portion and sub-bands of said second portion; and

in response to a determination that said signal data in said at least one sub-band comprises said at least one undesired signal contribution, initiate at least one notch filter within the receiver to affect said at least one undesired signal contribution.

57. The article as recited in claim 56, wherein said computer-implementable instructions are further executable by said processing unit to set:

a bandwidth of one or more of said plurality of sub-bands;

a center frequency of one or more of said plurality of sub-bands;

an integration time for one or more of said plurality of sub-bands;

or

a combination thereof.

58. The article as recited in claim 56, wherein said computer-implementable instructions are further executable by said processing unit to:

select said at least one sub-band; and

estimate a center frequency for said at least one undesired signal contribution.

59. The article as recited in claim 58, wherein said computer-implementable instructions are further executable by said processing unit to:

select said at least one sub-band;

collect signal samples in said selected sub-band;

apply Fourier analysis to said signal samples to generate a power spectrum for said selected sub-band; and

apply peak processing to said power spectrum to estimate one or more parameters for said at least one undesired signal contribution in said selected sub-band.

60. The article as recited in claim 58, wherein said computer-implementable instructions are further executable by said processing unit to:

non-coherently combine one or more power spectra for said at least one sub-band; and

apply a threshold to said combined power spectra.

61. The article as recited in claim 56, wherein two of said plurality of sub-bands are at least partially overlapping.

62. The article as recited in claim 56, wherein at least two of said plurality of sub-bands have different center frequencies and equal bandwidth sizes.

63. The article as recited in claim 56, wherein said spectral band is consumed by said plurality of sub-bands.

64. The article as recited in claim 56, wherein said computer-implementable instructions are further executable by said processing unit to:

obtain said signal data from at least one of a plurality of different processing stages in the receiver.

65. The article as recited in claim 56, wherein said signal data is obtained either before or after a filtering stage comprising said at least one notch filter.

66. The article as recited in claim 56, wherein said desired signal contribution comprises a SPS signal.

67. The article as recited in claim 56, wherein said at least one undesired signal contribution comprises a continuous wave signal that interferes with said desired signal.

68. The article as recited in claim 56, wherein said computer-implementable instructions are further executable by said processing unit to initiate said scan in response to one or more triggering events.

69. The article as recited in claim 68, wherein said one or more triggering events comprises at least one of:

a device or session initiation event;

an new channel initiation event;

a time-based event;

a frequency drift event;

an initiated scan event;

or a signal data threshold event.

70. The article as recited in claim 56, wherein said computer-implementable instructions are further executable by said processing unit to:

determine at least one parameter for said at least one undesired signal contribution.

71. The article as recited in claim 70, wherein said at least one parameter is indicative of at least one of:

an estimated power, an estimated bandwidth, or an estimated center frequency for said at least one undesired signal contribution.

72. The article as recited in claim 70, wherein said computer-implementable instructions are further executable by said processing unit to:

store said at least one parameter in memory; and

subsequently program said at least one notch filter based, at least in part, on said stored parameter.

73. The article as recited in claim 70, wherein said computer-implementable instructions are further executable by said processing unit to:

initiate transmission of said at least one parameter to at least one other device.

74. The article as recited in claim 73, wherein said computer-implementable instructions are further executable by said processing unit to:

initiate transmission of a current estimated position of the device to said at least one other device.

75. A method comprising, at a device comprising a receiver:

scanning at least one sub-band of a plurality of sub-bands within a spectral band of a received signal comprising a desired signal contribution to determine whether signal data obtained from said at least one sub-band further comprises at least one undesired signal contribution, wherein said at least one sub-band is selected for scanning based, at least in part, on a scan order that prioritizes scanning of said plurality of sub-bands based, at least in part, on a ranking of said plurality of sub-bands based on use in channel tracking, wherein a sub-band that is being used in said channel tracking has a higher rank than another sub-band that is not being used in said channel tracking, and wherein said at least one sub-band is further selected for said scanning based, at least in part, on a ranking in increasing order of differences between a center frequency of said spectral band and respective center frequencies of each of said plurality of sub-bands, wherein said respective center frequencies of a first portion of said plurality of sub-bands are greater than said center frequency of said spectral band, and said respective center frequencies of a second portion of said plurality of sub-bands are less than said center frequency of said spectral band, and wherein at least a part of said ranking in increasing order alternates between sub-bands of said first portion and sub-bands of said second portion; and

in response to determining that said signal data in said at least one sub-band comprises said at least one undesired signal contribution, initiating at least one notch filter within the receiver to affect said at least one undesired signal contribution.

76. The method as recited in claim 75, and further comprising, at said device:

determining at least one parameter based, at least in part, on said at least one undesired signal contribution; and

programming said at least one notch filter based, at least in part, on said at least one parameter.

77. An apparatus comprising:

means for scanning at least one sub-band of a plurality of sub-bands within a spectral band of a received signal comprising a desired signal contribution to determine whether signal data obtained from said at least one sub-band further comprises at least one undesired signal contribution, wherein said at least one sub-band is selected for scanning based, at least in part, on a scan order that prioritizes scanning of said plurality of sub-bands based, at least in part, on a ranking of said plurality of sub-bands based on use in channel tracking, wherein a sub-band that is being used in said channel tracking has a higher rank than another sub-band that is not being used in said channel tracking, and wherein said at least one sub-band is further selected for said scanning based, at least in part, on a ranking in increasing order of differences between a center frequency of said spectral band and respective center frequencies of each of said plurality of sub-bands, wherein said respective center frequencies of a first portion of said plurality of sub-bands are greater than said center frequency of said spectral band, and said respective center frequencies of a second portion of said plurality of sub-bands are less than said center frequency of said spectral band, and wherein at least a part of said ranking in increasing order alternates between sub-bands of said first portion and sub-bands of said second portion; and

means for initiating at least one notch filter within a receiver to affect said at least one undesired signal contribution, in response to a determination that said signal data in said at least one sub-band comprises said at least one undesired signal contribution.

78. The apparatus as recited in claim 77, and further comprising:

means for determining at least one parameter based, at least in part, on said at least one undesired signal contribution; and

means for programming said at least one notch filter based, at least in part, on said at least one parameter.

79. A device comprising:

a receiver;

at least one processing unit to;

scan at least one sub-band of a plurality of sub-bands within a spectral band of a received signal comprising a desired signal contribution to determine whether signal data obtained from said at least one sub-band further comprises at least one undesired signal contribution, wherein said at least one sub-band is selected for scanning based, at least in part, on a scan order that prioritizes scanning of said plurality of sub-bands based, at least in part, on a ranking of said plurality of sub-bands based on use in channel tracking, wherein a sub-band that is being used in said channel tracking has a higher rank than another sub-band that is not being used in said channel tracking, and wherein said at least one sub-band is further selected for said scanning based, at least in part, on a ranking in increasing order of differences between a center frequency of said spectral band and respective center frequencies of each of said plurality of sub-bands, wherein said respective center frequencies of a first portion of said plurality of sub-bands are greater than said center frequency of said spectral band, and said respective center frequencies of a second portion of said plurality of sub-bands are less than said center frequency of said spectral band, and wherein at least a part of said ranking in increasing order alternates between sub-bands of said first portion and sub-bands of said second portion; and

in response to a determination that said signal data in said at least one sub-band comprises said at least one undesired signal contribution, initiate at least one notch filter within said receiver to affect said at least one undesired signal contribution.

80. The device as recited in claim 79, said at least one processing unit to further:

determine at least one parameter based, at least in part, on said at least one undesired signal contribution; and

program said at least one notch filter based, at least in part, on said at least one parameter.

81. An article for use in a device comprising a receiver and a processing unit, the article comprising:

a non-transitory computer readable medium having stored therein computer-implementable instructions executable by the processing unit to;

scan at least one sub-band of a plurality of sub-bands within a spectral band of a received signal comprising a desired signal contribution to determine whether signal data obtained from said at least one sub-band further comprises at least one undesired signal contribution, wherein said at least one sub-band is selected for scanning based, at least in part, on a scan order that prioritizes scanning of said plurality of sub-bands based, at least in part, on a ranking of said plurality of sub-bands based on use in channel tracking, wherein a sub-band that is being used in said channel tracking has a higher rank than another sub-band that is not being used in said channel tracking, and wherein said at least one sub-band is further selected for said scanning based, at least in part, on a ranking in increasing order of differences between a center frequency of said spectral band and respective center frequencies of each of said plurality of sub-bands, wherein said respective center frequencies of a first portion of said plurality of sub-bands are greater than said center frequency of said spectral band, and said respective center frequencies of a second portion of said plurality of sub-bands are less than said center frequency of said spectral band, and wherein at least a part of said ranking in increasing order alternates between sub-bands of said first portion and sub-bands of said second portion; and

in response to a determination that said signal data in said at least one sub-band comprises said at least one undesired signal contribution, initiate at least one notch filter within the receiver to affect said at least one undesired signal contribution.

82. The article as recited in claim 81, wherein said computer-implementable instructions are further executable by the processing unit to:

determine at least one parameter based, at least in part, on said at least one undesired signal contribution; and

program said at least one notch filter based, at least in part, on said at least one parameter.