Star receiver burst processing

• US 7,200,185 B2
• Filed: 08/21/2001
• Issued: 04/03/2007
• Est. Priority Date: 08/21/2000
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Thesling, William H., Vanderaar, Mark
• Primary Examiner(s): Ghebretinsae; Temesghen
• Application Number:
  US09/934,299
• Publication Number:
  US 20020118737A1
• Time in Patent Office: 2,051 Days
• Field of Search: 375/326, 375/232, 375/316, 375/332, 375/371, 375/261, 375/329, 375/227, 375/260, 375/145, 375/149, 375/364, 375/368, 375/340, 375/148, 375/346, 375/140, 375/222, 375/274, 370/70, 370/210, 370/252, 370/343, 370/509, 370/513, 348/725, 709/225, 709/230, 709/253, 708/313, 708/290, 714/796, 455/73
• US Class Current: 375/316
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 27/2338 using sampling H04L27/2331 - H04L27/2335 take precedence

Abstract

Architecture for processing a record of burst information in a transmission link. A waveform sampler samples a received waveform containing a record of symbols imposed on a carrier signal. Symbol phase of the record symbols is determined utilizing one or more metrics. Any residual carrier error is corrected, and the carrier signal is removed. The phase and time-of-arrival of the burst information associated with a maximum positive correlation value are then determined.

Claims

1. A method of processing burst information in a transmission link, comprising the steps of:

receiving a sampled waveform containing a record of symbols imposed on a carrier signal;

determining symbol phase of said record of symbols utilizing one or more metrics;

processing said sample waveform to remove said carrier signal;

calculating phase ambiguity of the burst information;

resolving phase ambiguity of said sample waveform using the calculated phase ambiguity; and

indexing an arrival time of burst information;

wherein said symbol phase is determined with 5-points of correlation using sinusoidal functions.

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

locating a unique bit pattern of symbols in said record, said locating step comprising;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

3. The method recited in claim 1, further comprising:

locating a unique bit pattern of symbols in said record, wherein;

said unique bit pattern of symbols comprises an extended Hamming code word compatible for use in forward error correction decoding, and

said locating step comprises;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

4. The method recited in claim 1, further comprising:

locating a unique bit pattern of symbols in said record, said locating step comprising;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols, wherein;

said correlation parameters comprise a time offset value and a phase rotation value which are used to generate said maximum positive correlation.

5. The method recited in claim 1, wherein:

said sampled waveform is derived from a single channel per carrier waveform, and

said single channel comprises a plurality of time slices.

6. The method recited in claim 1, wherein said sampled waveform is derived from a TDMA signal.

7. The method recited in claim 1, wherein the step of processing comprises:

estimating residual carrier phase and frequency, and

down-converting to remove said carrier signal.

8. The method recited in claim 1, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and padded.

9. The method recited in claim 1, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and unpadded.

10. The method recited in claim 1, wherein said carrier signal is transmitted wirelessly.

11. The method recited in claim 1, wherein said carrier signal is transmitted wirelessly as part of a satellite return transmission link.

12. The method recited in claim 1, wherein at least one of said one or more metrics is a maximized square symbol amplitude.

13. The method recited in claim 1, wherein at least one of said one or more metrics is a maximized symbol amplitude.

14. The method recited in claim 1, wherein at least one of said one or more metrics is a minimized symbol variance.

15. An apparatus for processing burst information in a transmission link, comprising:

a waveform sampler for sampling a received waveform imposed on a carrier signal, said sampled waveform having a record of symbols;

a determinator for determining symbol phase of said record of symbols utilizing one or more metrics;

a processor for processing said sampled waveform to remove said carrier signal;

a resolver for determining phase ambiguity of the burst information; and

a detector for detecting a time of arrival of the burst information;

wherein said symbol phase is determined with 5-points of correlation using sinusoidal functions.

16. The apparatus recited in claim 15, further comprising:

a locator for locating a unique bit pattern of symbols in said record, said locator comprising a correlator for correlating said record of symbols with one or more predetermined sequences of symbols; and

a selector for selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

17. The apparatus recited in claim 15, further comprising:

a locator for locating a unique bit pattern of symbols in said record,

said unique bit pattern of symbols comprises an extended Hamming code word compatible for use in forward error correction decoding, and

said locator comprising a correlator for correlating said record of symbols with one or more predetermined sequences of symbols; and

a selector for selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

18. The apparatus recited in claim 15, further comprising:

a locator for locating a unique bit pattern of symbols in said record, said locator comprising a correlator for correlating said record of symbols with one or more predetermined sequences of symbols; and

a selector for selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols,

wherein said correlation parameters comprise a time offset value and a phase rotation value which are used to generate said maximum positive correlation.

19. The apparatus recited in claim 15, wherein:

said sampled waveform is derived from a single channel per carrier waveform, and

said single channel comprises a plurality of time slices.

20. The apparatus recited in claim 15, wherein said sampled waveform is derived from a TDMA signal.

21. The apparatus recited in claim 15, wherein the processor comprises:

an estimator for estimating residual carrier phase and frequency, and

a demodulator for down-converting to remove said carrier signal.

22. The apparatus recited in claim 15, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and padded.

23. The apparatus recited in claim 15, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and unpadded.

24. The apparatus recited in claim 15, wherein said carrier signal is transmitted wirelessly.

25. The apparatus recited in claim 15, wherein said carrier signal is transmitted wirelessly as part of a satellite return transmission link.

26. The apparatus recited in claim 15, wherein at least one of said one or more metrics is a maximized square symbol amplitude.

27. The apparatus recited in claim 15, wherein at least one of said one or more metrics is a maximized symbol amplitude.

28. The apparatus recited in claim 15, wherein at least one of said one or more metrics is a minimized symbol variance.

29. A method of processing burst information in a transmission link, comprising the steps of:

receiving a sampled waveform containing a record of symbols imposed on a carrier signal;

determining symbol timing of said record of symbols utilizing one or more metrics.

processing said sample waveform to remove said carrier signal by;

estimating residual carrier phase and frequency; and

down-converting to remove said carrier signal; and

determining phase ambiguity and burst arrival time by detecting a unique pattern of symbols word in said record of symbols, wherein phase ambiguity of said sample waveform is resolved using the determined phase ambiguity;

wherein symbol phase of said symbol timing is determined with 5-points of correlation using sinusoidal functions.

30. The method recited in claim 29, further comprising:

locating a unique bit pattern of symbols in said record, said locating step comprising;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

31. The method recited in claim 29, further comprising:

locating a unique bit pattern of symbols in said record, wherein;

said unique bit pattern of symbols comprises an extended Hamming code word compatible for use in forward error correction decoding, and

said locating step comprises;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

32. The method recited in claim 29, further comprising:

locating a unique bit pattern of symbols in said record, said locating step comprising;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols, wherein;

said correlation parameters comprise a time offset value and a phase rotation value which are used to generate said maximum positive correlation.

33. The method recited in claim 29, wherein:

said sampled waveform is derived from a single channel per carrier waveform, and

said single channel comprises a plurality of time slices.

34. The method recited in claim 29, wherein said sampled waveform is derived from a TDMA signal.

35. The method recited in claim 29, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and padded.

36. The method recited in claim 29, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and unpadded.

37. The method recited in claim 29, wherein said carrier signal is transmitted wirelessly.

38. The method recited in claim 29, wherein said carrier signal is transmitted wirelessly as part of a satellite return transmission link.

39. The method recited in claim 29, wherein at least one of said one or more metrics is a maximized square symbol amplitude.

40. The method recited in claim 29, wherein at least one of said one or more metrics is a maximized symbol amplitude.

41. The method recited in claim 29, wherein at least one of said one or more metrics is a minimized symbol variance.

42. An apparatus for processing burst information in a transmission link, comprising:

a waveform sampler for sampling a received waveform imposed on a carrier signal, said sampled waveform having a record of symbols;

a determinator of determining symbol timing of said record of symbols utilizing one or more metrics;

a processor for processing said sampled waveform in phase and frequency to remove said carrier signal;

a resolver for resolver phase ambiguity of burst information; and

a detector for detecting a time of arrival of the burst information;

wherein symbol phase of said symbol timing is determined with 5-points of correlation using sinusoidal functions.

43. The apparatus recited in claim 42, further comprising:

a locator for locating a unique bit pattern of symbols in said record, said locator comprising a correlator for correlating said record of symbols with one or more predetermined sequences of symbols; and

a selector for selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

44. The apparatus recited in claim 42, further comprising:

a locator for locating a unique bit pattern of symbols in said record,

said unique bit pattern of symbols comprises an extended Hamming code word compatible for use in forward error correction decoding, and

said locator comprising a correlator for correlating said record of symbols with one or more predetermined sequences of symbols; and

a selector for selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

45. The apparatus recited in claim 42, further comprising:

a locator for locating a unique bit pattern of symbols in said record, said locator comprising a correlator for correlating said record of symbols with one or more predetermined sequences of symbols; and

a selector for selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols,

wherein said correlation parameters comprise a time offset value and a phase rotation value which are used to generate said maximum positive correlation.

46. The apparatus recited in claim 42, wherein:

said sampled waveform is derived from a single channel per carrier waveform, and

said single channel comprises a plurality of time slices.

47. The apparatus recited in claim 42, wherein said sampled waveform is derived from a TDMA signal.

48. The apparatus recited in claim 42, wherein the processor comprises:

an estimator for estimating residual carrier phase and frequency, and

a demodulator for down-converting to remove said carrier signal.

49. The apparatus recited in claim 42, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and padded.

50. The apparatus recited in claim 42, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and unpadded.

51. The apparatus recited in claim 42, wherein said carrier signal is transmitted wirelessly.

52. The apparatus recited in claim 42, wherein said carrier signal is transmitted wirelessly as part of a satellite return transmission link.

53. The apparatus recited in claim 42, wherein at least one of said one or more metrics is a maximized square symbol amplitude.

54. The apparatus recited in claim 42, wherein at least one of said one or more metrics is a maximized symbol amplitude.

55. The apparatus recited in claim 42, wherein at least one of said one or more metrics is a minimized symbol variance.

56. A method of processing burst information in a transmission link, comprising the steps of:

receiving a sampled waveform containing a record of symbols imposed on a carrier signal;

determining symbol timing of said record of symbols utilizing one or more metrics;

processing said sample waveform in phase and frequency to remove said carrier signal;

calculating phase ambiguity of the burst information;

resolving phase ambiguity of said sample waveform using said calculated phase ambiguity; and

indexing an arrival time of the burst information;

wherein symbol phase of said symbol timing is determined in the step of determining with 5-points of correlation using sinusoidal functions.

57. The method recited in claim 56, further comprising:

locating a unique bit pattern of symbols in said record, said locating step comprising;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

58. The method recited in claim 56, further comprising:

locating a unique bit pattern of symbols in said record, wherein;

said unique bit pattern of symbols comprises an extended Hamming code word compatible for use in forward error correction decoding, and said locating step comprises;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

59. The method recited in claim 56, further comprising:

locating a unique bit pattern of symbols in said record, said locating step comprising;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols, wherein;

said correlation parameters comprise a time offset value and a phase rotation value which are used to generate said maximum positive correlation.

60. The method recited in claim 56, wherein:

said sampled waveform is derived from a single channel per carrier waveform, and

said single channel comprises a plurality of time slices.

61. The method recited in claim 56, wherein said sampled waveform is derived from a TDMA signal.

62. The method recited in claim 56, wherein the step of processing comprises:

estimating residual carrier phase and frequency, and

down-converting to remove said carrier signal.

63. The method recited in claim 56, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and padded.

64. The method recited in claim 56, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and unpadded.

65. The method recited in claim 56, wherein said carrier signal is transmitted wirelessly.

66. The method recited in claim 56, wherein said carrier signal is transmitted wirelessly as part of a satellite return transmission link.

67. The method recited in claim 56, wherein at least one of said one or more metrics is a maximized square symbol amplitude.

68. The method recited in claim 56, wherein at least one of said one or more metrics is a maximized symbol amplitude.

69. The method recited in claim 56, wherein at least one of said one or more metrics is a minimized symbol variance.

70. A method of processing burst information in a transmission link, comprising the steps of:

receiving a sampled waveform containing a record of symbols imposed on a carrier signal;

determining symbol timing of said record of symbols utilizing one or more metrics;

processing said sample waveform to remove said carrier signal; and

calculating phase ambiguity and time of arrival of the burst information by midamble detection, wherein phase ambiguity of said sample waveform is resolved using the calculated phase ambiguity;

wherein symbol phase of said symbol timing is determined in the step of determining with 5-points of correlation using sinusoidal functions.

71. The method recited in claim 70, further comprising:

locating a unique bit pattern of symbols in said record, said locating step comprising;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

72. The method recited in claim 70, further comprising:

locating a unique bit pattern of symbols in said record, wherein;

said unique bit pattern of symbols comprises an extended Hamming code word compatible for use in forward error correction decoding, and

said locating step comprises;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols.

73. The method recited in claim 70, further comprising:

locating a unique bit pattern of symbols in said record, said locating step comprising;

correlating said record of symbols with one or more predetermined sequences of symbols, and

selecting correlation parameters associated with a maximum positive correlation of said record of symbols and said one or more predetermined sequences of symbols, wherein;

said correlation parameters comprise a time offset value and a phase rotation value which are used to generate said maximum positive correlation.

74. The method recited in claim 70, wherein:

said sampled waveform is derived from a single channel per carrier waveform, and

said single channel comprises a plurality of time slices.

75. The method recited in claim 70, wherein said sampled waveform is derived from a TDMA signal.

76. The method recited in claim 70, wherein the step of processing comprises:

estimating residual carrier phase and frequency, and

down-converting to remove said carrier signal.

77. The method recited in claim 70, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and padded.

78. The method recited in claim 70, wherein the step of processing comprises:

computing a FFT on a block of symbols of said record of symbols, wherein said block of symbols is fixed and unpadded.

79. The method recited in claim 70, wherein said carrier signal is transmitted wirelessly.

80. The method recited in claim 70, wherein said carrier signal is transmitted wirelessly as part of a satellite return transmission link.

81. The method recited in claim 70, wherein at least one of said one or more metrics is a maximized square symbol amplitude.

82. The method recited in claim 70, wherein at least one of said one or more metrics is a maximized symbol amplitude.

83. The method recited in claim 70, wherein at least one of said one or more metrics is a minimized symbol variance.