Calibration system and method

• US 8,514,978 B2
• Filed: 12/22/2010
• Issued: 08/20/2013
• Est. Priority Date: 07/30/2010
• Status: Active Grant

• Current Assignee: National Instruments Corporation (Emerson Electric Company)
• Original Assignee: National Instruments Corporation (Emerson Electric Company)
• Inventors: Wertz, Daniel S., Corley, Charles L. II, Patel, Kunal H.
• Primary Examiner(s): LAM, KENNETH T
• Application Number:
  US12/976,638
• Publication Number:
  US 20120027063A1
• Time in Patent Office: 972 Days
• Field of Search: 375/316, 375/224, 375/225, 375/226, 375/227, 375/228, 375/354, 375/359
• US Class Current: 375/316
• CPC Class Codes: H04B 17/21 for calibration; for correcting measurements
• CPC Class Codes: H04B 17/364 Delay profiles
• CPC Class Codes: H04L 2025/03598 Algorithms

Abstract

Receiving a modulated carrier signal that is modulated using a reference signal, wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to a start of an acquisition within the digitizer. Further including routing the modulated carrier signal through a receiver system to generate a processed signal, receiving the processed signal at the digitizer, digitizing the processed signal at the digitizer, and determining a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.

Claims

1. A method comprising:

receiving, at a receiver system, a modulated carrier signal, wherein the carrier signal is modulated using a reference signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to a start of an acquisition within the digitizer, wherein the receiver system comprises an onboard signal source, the method further comprising generating the modulated carrier signal by modulating a signal provided from the onboard signal source of the receiver system;

routing the modulated carrier signal through the receiver system to generate a processed signal;

receiving the processed signal at the digitizer;

digitizing the processed signal at the digitizer; and

determining a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.

2. The method of claim 1, wherein the reference signal is generated by the digitizer.

3. The method of claim 1, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing offset of the processed signal with respect to the start of data acquisition at the digitizer.

4. The method of claim 1, further comprising modulating the carrier signal across a plurality of frequencies across an analysis bandwidth of the downconverter such that receiving, routing, receiving, digitizing and determining a delay are repeated for a plurality of frequencies across an analysis bandwidth of the receiver system.

5. The method of claim 4, further comprising determining delay vs. frequency data based on the determined delay, and generating an equalization filter based on the delay vs. frequency data.

6. The method of claim 5, further comprising:

receiving a radio-frequency (RF) signal from a source external to the receiver system;

routing the RF signal through the receiver device to generate a processed RF signal;

routing the processed RF signal to the digitizer;

receiving the processed RF signal at the digitizer; and

digitizing the processed RF signal at the digitizer, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system including the receiver device.

7. The method of claim 1, wherein the receiver system comprises a downconverter, and wherein routing the modulated carrier signal through the receiver system to generate a processed signal comprises routing the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal.

8. The method of claim 7, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.

9. A system, comprising:

a receiver system configured to;

receive a modulated a carrier signal, wherein the carrier signal is modulated using a reference signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to a start of an acquisition within the digitizer, wherein the receiver system comprises an onboard signal source, and wherein the receiver system is configured to generate the modulated carrier signal by modulating a signal provided from the onboard signal source; and

route the modulated carrier signal through the receiver system to generate a processed signal; and

the digitizer, configured to;

receive the processed signal;

digitize the processed signal; and

determine a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.

10. The system of claim 9, wherein the digitizer is configured to generate the reference signal.

11. The system of claim 9, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing of fset of the processed signal with respect to the start of data acquisition at the digitizer.

12. The system of claim 9, wherein the carrier signal is modulated across a plurality of frequencies across an analysis bandwidth of the downconverter such that modulating, routing, receiving, digitizing and determining a delay are repeated for a plurality of frequencies across the analysis bandwidth of the downconverter.

13. The system of claim 12, wherein the determined delays are used to determine delay vs. frequency data, and wherein the system is configured to generate an equalization filter based on the delay vs. frequency data.

14. The system of claim 13,

wherein the receiver system is further configured to:

receive a radio-frequency (RF) signal form a source external to the receiver system;

route the RF signal through the receiver system to generate a processed RF signal; and

wherein the digitizer is further configured to;

receive the processed RF signal at the digitizer; and

digitize the processed RF signal, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system.

15. The system of claim 9, wherein the receiver system comprises a downconverter, and wherein routing the modulated carrier signal through the receiver system to generate a processed signal comprises routing the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal.

16. The method of claim 15, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.

17. A non-transitory computer readable storage medium comprising program instruction stored thereon, wherein the program instructions are executable by a computer to cause:

receiving, at a receiver system, a modulated carrier signal wherein the carrier signal is modulated using a reference signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to the start of an acquisition within the digitizer, wherein the receiver system comprises an onboard signal source, and wherein the program instructions are further executable to cause generating the modulated carrier signal by modulating a signal provided from the onboard signal source of the receiver system;

routing the modulated carrier signal through the receiver system to generate a processed signal;

receiving the processed signal at the digitizer;

digitizing the processed signal at the digitizer; and

determining a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.

18. The non-transitory computer readable storage medium of claim 17, wherein the reference signal is generated by the digitizer.

19. The non-transitory computer readable storage medium of claim 17, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing offset of the processed signal with respect to the start of data acquisition at the digitizer.

20. The non-transitory computer readable storage medium of claim 17, wherein the program instructions are further executable to cause:

modulating the carrier signal across a plurality of frequencies across an analysis bandwidth of the downconverter such that execution of the program instructions causes the receiving, routing, receiving, digitizing and determining a delay to be repeated for a plurality of frequencies across an analysis bandwidth of the receiver system.

21. The non-transitory computer readable storage medium of claim 20, wherein execution of the program instructions causes generation of delay vs. frequency data based on the determined delay, and generation of an equalization filter based on the delay vs. frequency data.

22. The non-transitory computer readable storage medium of claim 21, wherein the program instructions are further executable to cause:

receiving a radio-frequency (RF) signal form a source external to the receiver system;

routing the RF signal through the receiver device to generate a processed RF signal;

routing the processed RF signal to the digitizer;

receiving the processed RF signal at the digitizer; and

digitizing the processed RF signal at the digitizer, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system including the receiver device.

23. The non-transitory computer readable storage medium of claim 17, wherein the receiver system comprises a downconverter, and wherein routing the modulated carrier signal through the receiver system to generate a processed signal comprises routing the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal.

24. The non-transitory computer readable storage medium of claim 23, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.

25. A system, comprising:

a downconverter receiver system configured to;

modulate a carrier signal generated from an onboard signal source of the downconverter receiver system, wherein the carrier signal is modulated using a reference signal provided from a digitizer such that the modulated carrier signal has known timing with respect to the start of an acquisition within the digitizer; and

route the modulated carrier signal through a receiver device of the downconverter receiver system to generate a processed signal;

wherein the digitizer is configured to;

receive the processed signal;

digitize the processed signal; and

determine a delay of the modulated carrier signal routed through the downconverter receiver system based on the timing of the processed signal.

26. A system, comprising:

a digitizer configured to;

provide a reference signal to a downconverter receiver system, wherein the downconverter receiver system is configured to;

modulate a carrier signal generated from an onboard signal source of the downconverter receiver system, wherein the carrier signal is modulated using the reference signal provided from the digitizer such that the modulated carrier signal has known timing with respect to the start of an acquisition within the digitizer; and

route the modulated carrier signal through a receiver device of the downconverter receiver system to generate a processed signal;

receive the processed signal;

digitize the processed signal; and

determine a delay of the modulated carrier signal routed through the downconverter receiver system based on the timing of the processed signal.

27. A method comprising:

receiving, at a receiver system, a modulated carrier signal, wherein the carrier signal is modulated using a reference signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to a start of an acquisition within the digitizer;

routing the modulated carrier signal through the receiver system to generate a processed signal;

receiving the processed signal at the digitizer;

digitizing the processed signal at the digitizer;

determining a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal; and

wherein the carrier signal is modulated across a plurality of frequencies across an analysis bandwidth of a downconverter such that said receiving the modulated carrier signal, said routing, said receiving the processed signal, said digitizing, and said determining a delay are repeated for a plurality of frequencies across an analysis bandwidth of the receiver system.

28. The method of claim 27, wherein the receiver system comprises an onboard signal source, and further comprising generating the modulated carrier signal by modulating a signal provided from the onboard signal source of the receiver system.

29. The method of claim 27, wherein the reference signal is generated by the digitizer.

30. The method of claim 27, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing offset of the processed signal with respect to the start of data acquisition at the digitizer.

31. The method of claim 27, further comprising determining delay vs. frequency data based on the determined delay, and generating an equalization filter based on the delay vs. frequency data.

32. The method of claim 31, further comprising:

receiving a radio-frequency (RF) signal from a source external to the receiver system;

routing the RF signal through the receiver device to generate a processed RF signal;

routing the processed RF signal to the digitizer;

receiving the processed RF signal at the digitizer; and

digitizing the processed RF signal at the digitizer, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system including the receiver device.

33. The method of claim 27, wherein the receiver system comprises the downconverter, and wherein said routing the modulated carrier signal through the receiver system to generate a processed signal comprises routing the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal.

34. The method of claim 33, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.

35. A system, comprising:

a receiver system configured to;

modulate a carrier signal using a reference signal, thereby generating a modulated carrier signal;

receive the modulated a carrier signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to a start of an acquisition within the digitizer; and

route the modulated carrier signal through the receiver system to generate a processed signal; and

the digitizer, configured to;

receive the processed signal;

digitize the processed signal; and

determine a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal;

wherein the carrier signal is modulated across a plurality of frequencies across an analysis bandwidth of a downconverter such that modulating, routing, receiving, digitizing and determining a delay are repeated for a plurality of frequencies across the analysis bandwidth of the downconverter.

36. The system of claim 35, wherein the receiver system comprises an onboard signal source and wherein the receiver system is configured to generate the modulated carrier signal by modulating a signal provided from the onboard signal source.

37. The system of claim 35, wherein the digitizer is configured to generate the reference signal.

38. The system of claim 35, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing offset of the processed signal with respect to the start of data acquisition at the digitizer.

39. The system of claim 35, wherein the determined delays are used to determine delay vs. frequency data, and wherein the system is configured to generate an equalization filter based on the delay vs. frequency data.

40. The system of claim 39,

wherein the receiver system is further configured to:

receive a radio-frequency (RF) signal form a source external to the receiver system;

route the RF signal through the receiver system to generate a processed RF signal; and

wherein the digitizer is further configured to;

receive the processed RF signal at the digitizer; and

digitize the processed RF signal, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system.

41. The system of claim 35, wherein the receiver system comprises the downconverter, and wherein routing the modulated carrier signal through the receiver system to generate a processed signal comprises routing the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal.

42. The method of claim 41, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.

43. A non-transitory computer readable storage medium comprising program instruction stored thereon, wherein the program instructions are executable by a computer to cause:

receiving, at a receiver system, a modulated carrier signal wherein the carrier signal is modulated using a reference signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to the start of an acquisition within the digitizer;

routing the modulated carrier signal through the receiver system to generate a processed signal;

receiving the processed signal at the digitizer;

digitizing the processed signal at the digitizer;

determining a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal; and

wherein the carrier signal is modulated across a plurality of frequencies across an analysis bandwidth of a downconverter such that execution of the program instructions causes the receiving, routing, receiving, digitizing and determining a delay to be repeated for a plurality of frequencies across an analysis bandwidth of the receiver system.

44. The non-transitory computer readable storage medium of claim 43, wherein the receiver system comprises an onboard signal source, wherein the program instructions are further executable to cause:

generating the modulated carrier signal by modulating a signal provided from the onboard signal source of the receiver system.

45. The non-transitory computer readable storage medium of claim 43, wherein the reference signal is generated by the digitizer.

46. The non-transitory computer readable storage medium of claim 43, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing offset of the processed signal with respect to the start of data acquisition at the digitizer.

47. The non-transitory computer readable storage medium of claim 43, wherein execution of the program instructions causes generation of delay vs. frequency data based on the determined delay, and generation of an equalization filter based on the delay vs. frequency data.

48. The non-transitory computer readable storage medium of claim 47, wherein the program instructions are further executable to cause:

receiving a radio-frequency (RF) signal from a source external to the receiver system;

routing the RF signal through the receiver device to generate a processed RF signal;

routing the processed RF signal to the digitizer;

receiving the processed RF signal at the digitizer; and

digitizing the processed RF signal at the digitizer, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system including the receiver device.

49. The non-transitory computer readable storage medium of claim 43, wherein the receiver system comprises the downconverter, and wherein said routing the modulated carrier signal through the receiver system to generate a processed signal comprises routing the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal.

50. The non-transitory computer readable storage medium of claim 49, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.

51. A method comprising:

receiving, at a receiver system, a modulated carrier signal, wherein the carrier signal is modulated using a reference signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to a start of an acquisition within the digitizer;

routing the modulated carrier signal through the receiver system to generate a processed signal, wherein the receiver system comprises a downconverter, and wherein said routing the modulated carrier signal through the receiver system to generate a processed signal comprises routing the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal;

receiving the processed signal at the digitizer;

digitizing the processed signal at the digitizer; and

determining a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.

52. The method of claim 51, wherein the receiver system comprises an onboard signal source, and further comprising generating the modulated carrier signal by modulating a signal provided from the onboard signal source of the receiver system.

53. The method of claim 51, wherein the reference signal is generated by the digitizer.

54. The method of claim 51, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing offset of the processed signal with respect to the start of data acquisition at the digitizer.

55. The method of claim 51, further comprising modulating the carrier signal across a plurality of frequencies across an analysis bandwidth of the downconverter such that receiving, routing, receiving, digitizing and determining a delay are repeated for a plurality of frequencies across an analysis bandwidth of the receiver system.

56. The method of claim 55, further comprising determining delay vs. frequency data based on the determined delay, and generating an equalization filter based on the delay vs. frequency data.

57. The method of claim 56, further comprising:

receiving a radio-frequency (RF) signal from a source external to the receiver system;

routing the RF signal through the receiver device to generate a processed RF signal;

routing the processed RF signal to the digitizer;

receiving the processed RF signal at the digitizer; and

digitizing the processed RF signal at the digitizer, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system including the receiver device.

58. The method of claim 51, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.

59. A system, comprising:

a receiver system configured to;

receive a modulated a carrier signal, wherein the carrier signal is modulated using a reference signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to a start of an acquisition within the digitizer; and

route the modulated carrier signal through the receiver system to generate a processed signal, wherein the receiver system comprises a downconverter, and wherein to route the modulated carrier signal through the receiver system to generate a processed signal, the receiver system is configured to route the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal; and

the digitizer, configured to;

receive the processed signal;

digitize the processed signal; and

determine a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.

60. The system of claim 59, wherein the receiver system comprises an onboard signal source and wherein the receiver system is configured to generate the modulated carrier signal by modulating a signal provided from the onboard signal source.

61. The system of claim 59, wherein the digitizer is configured to generate the reference signal.

62. The system of claim 59, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing offset of the processed signal with respect to the start of data acquisition at the digitizer.

63. The system of claim 59, wherein the carrier signal is modulated across a plurality of frequencies across an analysis bandwidth of the downconverter such that modulating, routing, receiving, digitizing and determining a delay are repeated for a plurality of frequencies across the analysis bandwidth of the downconverter.

64. The system of claim 63, wherein the determined delays are used to determine delay vs. frequency data, and wherein the system is configured to generate an equalization filter based on the delay vs. frequency data.

65. The system of claim 64,

wherein the receiver system is further configured to:

receive a radio-frequency (RF) signal form a source external to the receiver system;

route the RF signal through the receiver system to generate a processed RF signal; and

wherein the digitizer is further configured to;

receive the processed RF signal at the digitizer; and

digitize the processed RF signal, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system.

66. The method of claim 59, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.

67. A non-transitory computer readable storage medium comprising program instruction stored thereon, wherein the program instructions are executable by a computer to cause:

receiving, at a receiver system, a modulated carrier signal wherein the carrier signal is modulated using a reference signal, and wherein an acquisition by a digitizer is synced to the reference signal such that the modulated carrier signal has known timing with respect to the start of an acquisition within the digitizer, wherein the receiver system comprises a downconverter, and wherein said routing the modulated carrier signal through the receiver system to generate a processed signal comprises routing the modulated carrier signal through the downconverter to generate a processed signal that is a downconversion of the modulated carrier signal;

routing the modulated carrier signal through the receiver system to generate a processed signal;

receiving the processed signal at the digitizer;

digitizing the processed signal at the digitizer; and

determining a delay of the modulated carrier signal routed through the receiver system based on the timing of the processed signal.

68. The non-transitory computer readable storage medium of claim 67, wherein the receiver system comprises an onboard signal source, and further comprising generating the modulated carrier signal by modulating a signal provided from the onboard signal source of the receiver system.

69. The non-transitory computer readable storage medium of claim 67, wherein the reference signal is generated by the digitizer.

70. The non-transitory computer readable storage medium of claim 67, wherein determining a delay of the modulated carrier signal comprises analyzing digitized data generated by digitizing the processed signal at the digitizer, and determining the timing offset of the processed signal with respect to the start of data acquisition at the digitizer.

71. The non-transitory computer readable storage medium of claim 67, further comprising modulating the carrier signal across a plurality of frequencies across an analysis bandwidth of the downconverter such that execution of the program instructions causes the receiving, routing, receiving, digitizing and determining a delay to be repeated for a plurality of frequencies across an analysis bandwidth of the receiver system.

72. The non-transitory computer readable storage medium of claim 71, wherein execution of the program instructions causes generation of delay vs. frequency data based on the determined delay, and generation of an equalization filter based on the delay vs. frequency data.

73. The non-transitory computer readable storage medium of claim 72, further comprising:

receiving a radio-frequency (RF) signal form a source external to the receiver system;

routing the RF signal through the receiver device to generate a processed RF signal;

routing the processed RF signal to the digitizer;

receiving the processed RF signal at the digitizer; and

digitizing the processed RF signal at the digitizer, wherein digitizing the processed RF signal comprises applying the equalization filter to account for the delay of the receiver system including the receiver device.

74. The non-transitory computer readable storage medium of claim 67, wherein a reference clock of the digitizer is used to activate modulation write operations to eliminate jitter in the generation of amplitude modulation (AM) modulation pulses inside the downconverter.