Ghost cancellation reference signal with bessel chirps & PN sequences, & TV receiver using such signal

• US 6,184,938 B1
• Filed: 02/04/1999
• Issued: 02/06/2001
• Est. Priority Date: 04/22/1992
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Yang, Jian, Patel, Chandrakant Bhailalbhai
• Primary Examiner(s): LEE, MICHAEL
• Application Number:
  US09/246,182
• Time in Patent Office: 733 Days
• Field of Search: H04/N.521, 348/614, 348/608
• US Class Current: 348/614
• CPC Class Codes: H04N 5/211 Ghost signal cancellation H04N23/81 takes precedence
• CPC Class Codes: H04N 5/44 Receiver circuitry for the reception of television signals according to analogue transmission standards H04N5/14 takes precedence

Abstract

Composite ghost cancellation reference (GCR) signals that make available both a chirp and a PN sequence during the same vertical-blanking-interval (VBI) scan line in each successive field facilitate more rapid and efficient calculations of ghost cancellation and of equalization, on a continuing basis. A television receiver for use with such composite GCR signals includes circuitry for separating the chirp and PN sequence portions of the GCR signals from the remainder of the composite video signal, a ghost cancellation filter and an equalization filter connected in cascade to respond to the composite video signal and provided each with adjustable filtering weights, and a computer. Random-access memory addressed during writing snatches the vertical-blanking-interval scan lines selected to include GCR signals. Sets of four successive ones of the selected scan lines are then additively and subtractively combined to separate the chirp portions of the GCR signals from a remainder of the composite video signal.

The sets of selected scan lines are additively and subtractively combined in another way to separate the PN sequence portions of the GCR signals form a remainder of the composite video signal. The computer responds to the separated chirp portions of the GCR signals to calculate a discrete Fourier transform (DFT) therefrom. The computer proceeds from that DFT to determine the adjustable filtering weights of the ghost cancellation filter. The computer thereafter responds to the separated PN sequences to determine the adjustable filtering weights of the equalization filter.

Claims

1. A television receiver for use with ghost-cancellation-reference signals of a type that include both a chirp and a pseudo-noise sequence in a selected scan line of a vertical blanking interval of each field of a composite video signal, said television receiver comprising:

means for separating the chirp and pseudo-noise sequence portions of the ghost-cancellation-reference signals from the remainder of the composite video signal; and

a ghost cancellation filter provided with adjustable filtering weights;

an equalization filter provided with adjustable filtering weights and connected in cascade with said ghost cancellation filter to respond to the composite video signal;

means responding to the separated chirp portions of the ghost-cancellation-reference signals to calculate a discrete Fourier transform therefrom;

means responding to said discrete Fourier transform to determine values of the adjustable filtering weights of the ghost cancellation filter; and

means responding to the separated pseudo-noise sequence portions of the ghost-cancellation-reference signals to determine values of the adjustable filtering weights of the equalization filter.

2. A television receiver as set forth in claim 1, wherein said means for separating the chirp and pseudo noise sequence portions of the ghost-cancellation-reference signals from the remainder of the composite video signal comprises:

means for selecting scan lines with said ghost-cancellation-reference signals from the vertical blanking interval of each field;

means for additively and subtractively combining selected scan lines in sets of four successive ones of said selected scan lines, so as to separate the chirp portions of the ghost-cancellation-reference signals from a remainder of the composite video signal; and

means for additively and subtractively combining selected scan lines in sets of four successive ones of said selected scan lines, so as to separate the pseudo noise sequence portions of the ghost-cancellation-reference signals from a remainder of the composite video signal.

3. A television receiver for receiving television signals of a type wherein a composite video signal including a ghost-cancellation reference signal therewithin is transmitted, said ghost-cancellation reference signal including within an active portion of each of selected scan lines both a chirp signal and a subsequent pseudo-noise sequence, wherein in each pair of successive pairs of said selected scan lines both scan lines have respective chirp signals of the same sense as each other, wherein within each said pair of selected scan lines the two scan lines have respective pseudo noise sequences of opposite sense to each other, wherein successive ones of said selected scan lines occur in successive vertical blanking intervals of said composite video signal, and wherein the two selected scan lines in each succeeding said pair of selected scan lines have respective chirp signals of opposite sense to the respective chirp signals in the preceding said pair of selected scan lines, said television receiver comprising:

means for responding to a selected one of said television signals to supply said composite video signal;

means for additively and subtractively combining selected scan lines in sets of four successive ones of said selected scan lines so as to separate chirp portions of the ghost-cancellation-reference signals from a remainder of said composite video signal;

means for additively and subtractively combining selected scan lines in sets of four successive ones of said selected scan lines so as to separate the pseudo noise sequence portions of the ghost-cancellation-reference signals from a remainder of said composite video signal;

a ghost cancellation filter provided with adjustable filtering weights;

an equalization filter provided with adjustable filtering weights and connected in cascade with said ghost cancellation filter to respond to said composite video signal;

means responding to the separated chirp portions of the ghost-cancellation-reference signals to calculate a discrete Fourier transform therefrom;

means responding to said discrete Fourier transform to determine values of the adjustable filtering weights of the ghost cancellation filter; and

means responding to the separated pseudo noise sequence portions to determine values of the adjustable filtering weights of the equalization filter.

4. A television receiver for television signals including ghost-cancellation-reference signals of a type that include chirp information comprising a single chirp with pedestal in a selected scan line of the vertical blanking interval of each field, consecutive ones of which chirps alternate being first and second senses in a prescribed pattern, said television receiver comprising:

means for responding to a selected one of said television signals to supply a composite video signal;

means for separating the chirp information from a remainder of said composite video signal, including;

means for selecting an even-numbered plurality of said scan lines with chirps from respective ones of said vertical blanking intervals, and

means for combining corresponding samples of said even-numbered plurality of said selected scan lines to generate respective samples of said chirp information without accompanying pedestal;

a ghost cancellation filter provided with adjustable filtering weighs; and

means responding to the separated chirp information for computing values for the adjustable filtering weights of the ghost cancellation filter.

5. A television receiver as set forth in claim 4, wherein said means responding to the separated chirp information for computing values of the adjustable filtering weights of the ghost cancellation filter comprises:

means responding to the separated chirp information of the ghost-cancellation-reference signals to calculate a discrete Fourier transform therefrom; and

means responding to said discrete Fourier transform to determine the values of the adjustable filtering weights of the ghost cancellation filter.

6. A television receiver as set forth in claim 5 wherein said even-numbered plurality of said selected scan lines includes four scan lines.

7. A television receiver as set forth in claim 5 wherein said even-numbered plurality of said selected scan lines includes a multiple of four scan lines.

8. A television receiver as set forth in claim 4 wherein said even-numbered plurality of said selected scan lines includes four scan lines.

9. A television receiver as set forth in claim 4 wherein said even-numbered plurality of said selected scan lines includes a multiple of four scan lines.

10. A television receiver as set forth in claim 4, including means for separating information concerning the pedestals of said chirp information, separated from said chirp information, which means comprises:

means for selecting an even-numbered plurality of said scan lines with chirps from respective ones of said vertical blanking intervals, and

means for combining corresponding samples of said even-numbered plurality of said selected scan lines to generate respective samples of said information concerning the pedestals of said chirp information, separated from said chirp information.

11. A television receiver for television signals including ghost-cancellation-reference signals of a type that include chirp information and pedestal information together comprising a single chirp with pedestal in a selected scan line of a vertical blanking interval of each field, consecutive ones of which chirps alternate being first and second senses in a prescribed pattern, said television receiver including:

means for responding to a selected one of said television signals to supply a composite video signal;

means for separating said pedestal information from said chirp information, which means comprises;

means for selecting an even-numbered plurality of said scan lines with chirps from respective ones of said vertical blanking intervals, and means for combining corresponding samples of said even-numbered plurality of said selected scan lines to generate respective samples of said pedestal information separated from said chirp information.

12. A television receiver for television signals including ghost-cancellation-reference signals of a type that include a single chirp with pedestal in a selected scan line of the vertical blanking interval of each field, consecutive ones of which chirps alternate being first and second senses in a prescribed patter, said television receiver comprising:

means for responding to a selected one of said television signals to supply a composite video signal;

means for separating chirp information from the remainder of the composite video signal, including;

means for selecting an even-numbered plurality of said scan lines with chirps from respective ones of said vertical blanking intervals, said even-numbered plurality being a multiple of four, each of which selected scan lines includes front porch, horizontal synchronizing pulse, back porch, color burst and a pedestal for the chirp therewithin;

means for combining corresponding samples of said even-numbered plurality of said selected scan lines to generate respective samples of said chirp information without accompanying front porch, horizontal synchronizing pulse, back porch, color burst or pedestal;

a ghost cancellation filter provided with adjustable filtering weights; and

means responding to the separated chirp information for computing values of the adjustable filtering weights of the ghost cancellation filter.

13. A communication system, comprising:

means for generating video signals;

means for inserting ghost canceling reference signals in each vertical blanking interval of said video signals, said ghost canceling reference signals comprising pseudo-random noise sequences and chirp signals of different predefined signal characteristics;

transmission means for enabling transmission of said video signals containing said ghost canceling reference signals; and

ghost canceling means for enabling reception of said video signals containing said ghost canceling reference signals transmitted by said transmission means and processing said ghost canceling reference signals contained in said received video signals to eliminate channel transmission delay distortion, said ghost canceling means comprising;

means for separating the chirp signals and the pseudo-random noise sequences of the ghost cancellation reference signals from the received video signals;

a ghost cancellation filter provided with adjustable filtering weights;

an equalization filter provided with adjustable filtering weights and connected in cascade with said ghost cancellation filter to respond to the received video signals;

means responding to the separated chirp signals to calculate a discrete Fourier transform therefrom;

means responding to said discrete Fourier transform to determine the adjustable filtering weights of said ghost cancellation filter for enabling said ghost cancellation filter to cancel ghost components of said received video signals resulting from said channel transmission delay distortion; and

means responding to the separated pseudo-random noise sequences to determine the adjustable filtering weights of said equalization filter for enabling said equalization filter to provide a flat spectrum over the entire frequency range for said ghost cancellation reference signals transmission.

14. A communication system as claimed in claim 13, wherein said pseudo-random noise sequences and chirp signals are included within an active portion of each of selected scan lines in each vertical blanking interval, and within each of said selected scan lines in each vertical blanking interval said chirp signals precede said pseudo-random noise sequences.

15. An apparatus for receiving a plurality of signals divided into a plurality of cyclic fields, each including field synchronization signals and a vertical blanking period which further includes a plurality of horizontal scanning periods, wherein at least two of said horizontal scanning periods in a single vertical blanking period include two different reference signals, one of said reference signals being a pseudo-random noise sequence and the other being a chirp signal, said apparatus including a channel characterization means comprising:

a reference signal processing means for processing said received signals including said two different reference signals in said two horizontal scanning periods within said single vertical blanking period, said reference signal processing means comprising;

means for separating said chirp signal and said pseudo-random noise sequence of said reference signals from said received signals;

a ghost cancellation filter provided with adjustable filtering weights;

an equalization filter provided with adjustable filtering weights and connected in cascade with said ghost cancellation filter to respond to said received signals;

means responding to the separated chirp signals of said reference signals to calculate a discrete Fourier transform therefrom;

means responding to said discrete Fourier transform to determine values of the adjustable filtering weights of the ghost cancellation filter; and

means responding to the separated pseudo-random noise sequence of said reference signals to determine values of the adjustable filtering weights of the equalization filter.

16. The apparatus of claim 15, wherein said means for separating said chirp signal and said pseudo-random noise sequence of said reference signals from said received signals comprises:

means for selecting scan lines with said reference signals from said vertical blanking interval of each cyclic field;

means for additively and subtractively combining selected scan lines in sets of four successive horizontal scanning periods so as to separate said chirp signal of said reference signals from a remainder of said received signals; and

means for additively and subtractively combining selected scan lines in sets of four successive horizontal scanning periods so as to separate said pseudo-random noise sequence of said reference signals from a remainder of said received signals.

17. A receiver for receiving a television signal divided into a plurality of successive fields each comprising a prescribed number of lines of information, said lines being of uniform respective duration, a prescribed single line of each of said fields including a first ghost-cancellation reference signal and a second ghost-cancellation reference signal different than said first ghost-cancellation reference signal, the relative phases of said first and said second ghost-cancellation reference signals varying from field to field in prescribed pattern, said first ghost-cancellation reference signal having a prescribed first duration longer than half a line duration and said second ghost-cancellation reference signal comprising a pseudo-noise (PN) sequence and having a prescribed second duration shorter than half a line duration, said receiver apparatus comprising:

circuitry for separating said first ghost-cancellation reference signal and any ghosting thereof from said second ghost-cancellation reference signal and any ghosting thereof;

circuitry for characterizing a reception channel responsive to said first ghost-cancellation reference signal and said any ghosting thereof; and

an adaptive filter for said television signal, the parameters of which adaptive filter are adjusted responsive to said characterizing of the reception channel for suppressing ghosting in the response of said adaptive filter.

18. The receiver of claim 17, wherein said circuitry for characterizing the reception channel includes:

a read-only memory operated to supply the discrete Fourier transform of a first ideal signal corresponding to said first ghost-cancellation reference signal without any attendant ghosting;

circuitry for calculating the discrete Fourier transform of said first ghost-cancellation reference signal as received with ghosting and separated from said second ghost-cancellation reference signal, and dividing the terms of the discrete Fourier transform of said separated first ghost-cancellation reference signal as received with ghosting by corresponding terms of said discrete Fourier transform of said first ideal signal supplied from said read-only memory, thereby to generate a discrete Fourier transform characterizing the reception channel.

19. The receiver of claim 17, wherein said adaptive filter is a ghost cancellation filter, said receiver further comprising:

circuitry for separating said second ghost-cancellation reference signal and any ghosting thereof from said first ghost-cancellation reference signal and any ghosting thereof,

a read-only memory operated to supply the discrete Fourier transform of a second ideal signal corresponding to said second ghost-cancellation reference signal without any attendant ghosting;

circuitry for calculating the discrete Fourier transform of said second ghost-cancellation reference signal as received with ghosting and separated from said first ghost-cancellation reference signal, and dividing the terms of the discrete Fourier transform of said separated second ghost-cancellation reference signal as received with ghosting by corresponding terms of said discrete Fourier transform of a second ideal signal supplied from said read-only memory, thereby to generate a discrete Fourier transform characterizing the reception channel; and

a further adaptive filter for said television signal, the parameters of which adaptive filter are adjusted responsive to said characterizing of the reception channel, for reducing the departure of the spectral response of said reception channel from a desired spectral response.

20. The receiver of claim 17, wherein said adaptive filter is a ghost cancellation filter, said receiver further comprising:

circuitry for separating said second ghost-cancellation reference signal and any ghosting thereof from said first ghost-cancellation reference signal and any ghosting thereof;

circuitry responsive to said second ghost-cancellation reference signal and said any ghosting thereof for calculating the departure of the spectral response of said reception channel from a desired spectral response; and

a further adaptive filter for said television signal, the parameters of which adaptive filter are adjusted for reducing the departure of the spectral response of said reception channel from said desired spectral response.

21. A receiver comprising:

detection circuitry for recovering a digitized baseband signal by detecting a transmitted signal having a succession of frames, each of said frames comprising an odd-numbered field followed by an even-numbered field, each of said fields comprising a specified number of lines with only a particular one of said lines being designated to carry a respective transmission equalization reference signal comprising a first component transmission equalization reference signal and a second component transmission equalization reference signal, said first component transmission equalization reference signals being of the same amplitude and sense of polarity in both said odd-numbered field and said even-numbered field of each said frame, said second component transmission equalization reference signals being the same in amplitude in both said odd-numbered field and said even-numbered field of each said frame but opposite in sense of polarity;

circuitry for separating from said digitized baseband signal said lines designated for carrying a respective transmission equalization reference signal;

memory for temporarily storing a number of said designated lines as separated;

combining circuitry for separating said second component transmission equalization reference signal from said transmission equalization reference signals by combining a most current one of said designated lines with at least one temporarily stored previous one of said designated lines;

an equalization filter with adjustable filtering weights, said equalization filter connected for responding to said digitized baseband signal; and

an equalization weight computer responding to said second component transmission equalization reference signal separated by said combining circuitry to determine said adjustable filtering weights of the equalization filter.

22. The receiver of claim 21, further characterized in that each said second component transmission equalization reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

23. The receiver of claim 22, further characterized in that said combining circuitry is of a type for separating said PN sequences of said prescribed first length from said transmission equalization reference signals by differentially combining said designated lines that are in different fields of the same frame.

24. The receiver of claim 21 further characterized in that, in each said particular one of said lines that is designated for carrying a respective transmission equalization reference signal, said second component transmission equalization reference signal is of shorter duration than said first component transmission equalization reference signal.

25. The receiver of claim 24 further characterized in that, in each said particular one of said lines that is designated for carrying a respective transmission equalization reference signal, said second component transmission equalization reference signal follows said first component transmission equalization reference signal.

26. The receiver of claim 25, further characterized in that each said second component transmission equalization reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

27. The receiver of claim 26, further characterized in that said combining circuitry is of a type for separating said PN sequences of said prescribed first length from said transmission equalization reference signals by differentially combining said designated lines that are in different fields of the same frame.

28. The receiver of claim 24, further characterized in that each said second component transmission equalization reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

29. The receiver of claim 28, further characterized in that said combining circuitry is of a type for separating said PN sequences of said prescribed first length from said transmission equalization reference signals by differentially combining said designated lines that are in different fields of the same frame.

30. The receiver of claim 21, further characterized in that said combining circuitry is of a type for separating said second component transmission equalization reference signals by combining an even number, at least four, of said designated lines.

31. The receiver of claim 30, further characterized in that each said second component transmission equalization reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

32. The receiver of claim 30 further characterized in that, in each said particular one of said lines that is designated for carrying a respective transmission equalization reference signal, said second component transmission equalization reference signal is of shorter duration than said first component transmission equalization reference signal.

33. The receiver of claim 32 further characterized in that, in each said particular one of said lines that is designated for carrying a respective transmission equalization reference signal, said second component transmission equalization reference signal follows said first component transmission equalization reference signal.

34. The receiver of claim 33, further characterized in that each said second component transmission equalization reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

40. The receiver of claim 31, further characterized in that each said second component ghost-cancellation reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

41. The receiver of claim 40, further characterized in that said combining circuitry is of a type for separating said pseudo-noise (PN) sequences of said prescribed first length from said ghost-cancellation reference signals by differentially combining said designated lines that are in different fields of the same frame.

35. A receiver comprising:

circuitry for recovering a digitized baseband signal by detecting a television signal having a succession of frames, each of said frames comprising an odd-numbered field followed by an even-numbered field, each of said fields comprising a specified number of lines only a particular one of which said lines is designated for carrying a respective ghost-cancellation reference signal comprising a first component ghost-cancellation reference signal and a second component ghost-cancellation reference signal, said first component ghost-cancellation reference signals being of the same amplitude and sense of polarity in both said odd-numbered field and said even-numbered field of each said frame, said second component ghost-cancellation reference signals being the same in amplitude in both said odd-numbered field and said even-numbered field of each said frame but opposite in sense of polarity;

circuitry for separating from said digitized baseband signal said lines designated for carrying a ghost-cancellation reference signal;

memory for temporarily storing a number of said designated lines as separated;

combining circuitry for separating said second component ghost-cancellation reference signal from said designated lines by combining a most current one of said designated lines with at least one temporarily stored previous one of said designated lines;

an equalization filter with adjustable filtering weights, said equalization filter connected for responding to said digitized baseband signal; and

an equalization weight computer responding to said second component ghost-cancellation reference signal separated by said combining circuitry to determine said adjustable filtering weights of the equalization filter.

36. The receiver of claim 35, further characterized in that each said second component ghost-cancellation reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

37. The receiver of claim 36, further characterized in that said combining circuitry is of a type for separating said pseudo-noise (PN) sequences of a prescribed first length from said ghost-cancellation reference signals by differentially combining said designated lines that are in the same frame.

38. The receiver of claim 35 further characterized in that, in each said particular one of said lines that is designated for carrying a respective ghost-cancellation reference signal, said second component ghost-cancellation reference signal is of shorter duration than said first component ghost-cancellation reference signal.

39. The receiver of claim 35 further characterized in that, in each said particular one of said lines that is designated for carrying a respective ghost-cancellation reference signal, said second component ghost-cancellation reference signal follows said first component ghost-cancellation reference signal.

42. The receiver of claim 38, further characterized in that each said second component ghost-cancellation reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

43. The receiver of claim 42, further characterized in that said combining circuitry is of a type for separating said pseudo-noise (PN) sequences of said prescribed first length from said ghost-cancellation reference signals by differentially combining said designated lines that are in different fields of the same frame.

44. The receiver of claim 35, further characterized in that said combining circuitry is of a type for separating said second component ghost-cancellation reference signals by combining an even number, at least four, of said designated lines.

45. The receiver of claim 44, further characterized in that each said second component ghost-cancellation reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

46. The receiver of claim 44 further characterized in that, in each said particular one of said lines that is designated for carrying a respective ghost-cancellation reference signal, said second component ghost-cancellation reference signal is of shorter duration than said first component ghost-cancellation reference signal.

47. The receiver of claim 46 further characterized in that, in each said particular one of said lines that is designated for carrying a respective ghost-cancellation reference signal, said second component ghost-cancellation reference signal follows said first component ghost-cancellation reference signal.

48. The receiver of claim 47, further characterized in that each said second component ghost-cancellation reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

49. A receiver comprising:

detection circuitry for recovering a digitized baseband signal by detecting a transmitted signal having a succession of frames, each of said frames comprising an odd-numbered field followed by an even-numbered field, each of said fields comprising a specified number of lines, a particular one of which said lines is designated for carrying a respective transmission equalization reference signal comprising a first component transmission equalization reference signal and a second component transmission equalization reference signal of shorter duration than said first component transmission equalization reference signal;

separator circuitry for separating each of said first and second component transmission equalization reference signals from said digitized baseband signal;

a ghost cancellation filter and an equalization filter connected in cascade for responding to said digitized baseband signal, each filter having adjustable filtering weights; and

filter weight computation circuitry for determining said adjustable filtering weights of said ghost cancellation filter responsive to said first component transmission equalization reference signals separated by said separator circuitry, and for determining said adjustable filtering weights of said equalization filter responsive to said second component transmission equalization reference signals separated by said separator circuitry.

50. The receiver of claim 49, further characterized in that said filter weight computation circuitry comprises:

a ghost cancellation filter weight computer responding to said first component transmission equalization reference signals separated by said separator circuitry to determine said adjustable filtering weights of said ghost cancellation filter; and

an equalization filter weight computer responding to said second component transmission equalization reference signals separated by said separator circuitry to determine said adjustable filtering weights of said equalization filter.

51. The receiver of claim 50, further characterized in that said ghost cancellation filter weight computer is arranged to calculate a discrete Fourier transform (DFT) in response to said first component transmission equalization reference signals separated by said separator circuitry and determines said adjustable filtering weights of the ghost cancellation filter from that DFT.

52. The receiver of claim 49, further characterized in that said separator circuitry is of a type for separating said first component transmission equalization reference signals by combining an even number at least four of said designated lines.

53. A receiver comprising:

detection circuitry for recovering a digitized baseband signal by detecting a transmitted signal having a succession of frames, each of said frames comprising an odd-numbered field followed by an even-numbered field, each of said fields comprising a specified number of lines, a particular one of which said lines is designated for carrying a respective transmission equalization reference signal comprising a first component transmission equalization reference signal and a second component transmission equalization reference signal of shorter duration than said first component transmission equalization reference signal, said first component transmission equalization reference signals being of the same amplitude and sense of polarity in both said odd-numbered field and said even-numbered field of each said frame, said second component transmission equalization reference signals being the same in amplitude in both said odd-numbered field and said even-numbered field of each said frame but opposite in sense of polarity;

circuitry for separating from said digitized baseband signal said lines designated for carrying a transmission equalization reference signal;

memory for temporarily storing a number of said designated lines as separated;

combining circuitry for separating from said transmission equalization reference signals said first component transmission equalization reference signal and said second component transmission equalization reference signal by combining a most current one of said designated lines with at least one temporarily stored previous one of said designated lines;

a ghost cancellation filter and an equalization filter connected in cascade for responding to said digitized baseband signal, each filter having adjustable filtering weights; and

filter weight computation circuitry for determining said adjustable filtering weights of said ghost cancellation filter responsive to said first component transmission equalization reference signals separated by said combining circuitry, and for determining said adjustable filtering weights of said equalization filter responsive to said second component transmission equalization reference signals separated by said combining circuitry.

54. The receiver of claim 53, further characterized in that said filter weight computation circuitry comprises:

a ghost cancellation filter weight computer responding to said first component transmission equalization reference signals separated by said combining circuitry to determine said adjustable filtering weights of said ghost cancellation filter; and

an equalization filter weight computer responding to said second component transmission equalization reference signals separated by said combining circuitry to determine said adjustable filtering weights of said equalization filter.

55. The receiver of claim 54, further characterized in that said ghost cancellation filter weight computer is arranged to calculate a discrete Fourier transform (DFT) in response to said first component transmission equalization reference signals separated by said combining circuitry and determines said adjustable filtering weights of the ghost cancellation filter from that DFT.

56. The receiver of claim 53, further characterized in that said combining circuitry is of a type for separating said first component transmission equalization reference signals and said second component transmission equalization reference signals by combining an even number, at least four, of said designated lines.

57. A receiver as set forth in claim 53, further characterized in that in each of said transmission equalization reference signals said first component transmission equalization reference signal precedes said second component transmission equalization reference signal.

58. The receiver of claim 57, further characterized in that said filter weight computation circuitry comprises:

a ghost cancellation filter weight computer responding to said first component transmission equalization reference signals separated by said combining circuitry to determine said adjustable filtering weights of said ghost cancellation filter; and

an equalization filter weight computer responding to said second component transmission equalization reference signals separated by said combining circuitry to determine said adjustable filtering weights of said equalization filter.

59. The receiver of claim 58, further characterized in that said ghost cancellation filter weight computer responds to said first component transmission equalization reference signals separated by said combining circuitry to calculate a discrete Fourier transform (DFT) therefrom and determines said adjustable filtering weights of the ghost cancellation filter from that DFT.

60. The receiver of claim 57, further characterized in that said combining circuitry is of a type for separating said first component transmission equalization reference signals and said second component transmission equalization reference signals by combining an even number, at least four, of said designated lines.

61. The receiver of claim 53, further characterized in that each said second component transmission equalization reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

62. The receiver of claim 61, further characterized in that said filter weight computation circuitry comprises:

a ghost cancellation filter weight computer responding to said first component transmission equalization reference signals separated by said combining circuitry to determine said adjustable filtering weights of said ghost cancellation filter; and

an equalization filter weight computer responding to said second component transmission equalization reference signals separated by said combining circuitry to determine said adjustable filtering weights of said equalization filter.

63. The receiver of claim 62, further characterized in that said ghost cancellation filter weight computer responds to said first component transmission equalization reference signals separated by said combining circuitry to calculate a discrete Fourier transform (DFT) therefrom and determines said adjustable filtering weights of the ghost cancellation filter from that DFT.

64. The receiver of claim 61, further characterized in that said combining circuitry is of a type for separating said first component transmission equalization reference signals and said second component transmission equalization reference signals by combining an even number, at least four, of said designated lines.

65. A receiver comprising:

circuitry for recovering a digitized baseband signal by detecting a television signal having a succession of frames, each of said frames comprising an odd-numbered field followed by an even-numbered field, each of said fields comprising a specified number of lines with a particular one of said lines being designated to carry a respective ghost-cancellation reference signal comprising a first component ghost-cancellation reference signal and a second component ghost-cancellation reference signal of shorter duration than said first component ghost-cancellation reference signal;

separator circuitry for separating each of said first and second component ghost-cancellation reference signals from said digitized baseband signal;

a ghost cancellation filter and an equalization filter connected in cascade for responding to said digitized baseband signal, each filter having adjustable filtering weights; and

filter weight computation circuitry for determining said adjustable filtering weights of said ghost cancellation filter responsive to said first component ghost-cancellation reference signal separated by said separator circuitry, and for determining said adjustable filtering weights of said equalization filter responsive to said second component ghost-cancellation reference signal separated by said separator circuitry.

66. The receiver of claim 65, further characterized in that said filter weight computation circuitry comprises:

a ghost cancellation filter weight computer responding to said first component ghost-cancellation reference signals separated by said separator circuitry to determine said adjustable filtering weights of said ghost cancellation filter; and

an equalization filter weight computer responding to said second component ghost-cancellation reference signals separated by said separator circuitry to determine said adjustable filtering weights of said equalization filter.

67. The receiver of claim 66, further characterized in that said ghost cancellation filter weight computer is arranged to calculate a discrete Fourier transform (DFT) in response to said first component ghost-cancellation reference signal separated by said combing circuitry and determines said adjustable filtering weights of the ghost cancellation filter from that DFT.

68. A receiver comprising:

circuitry for recovering a digitized baseband signal by detecting a television signal having a succession of frames, each of said frames comprising an odd-numbered field followed by an even-numbered field, each of said fields comprising a specified number of lines with a particular one of said lines being designated to carry a respective ghost-cancellation reference signal comprising a first component ghost-cancellation reference signal and a second component ghost-cancellation reference signal of shorter duration than said first component ghost-cancellation reference signal, said first component ghost-cancellation reference signal being of the same amplitude and sense of polarity in both said odd-numbered field and said even-numbered field of each said frame, said second component ghost-cancellation reference signal being the same in amplitude in both said odd-numbered field and said even-numbered field of each said frame but opposite in sense of polarity;

circuitry for separating from said digitized baseband signal said lines designated for carrying a ghost-cancellation reference signal;

memory for temporarily storing a number of said designated lines as separated;

combining circuitry for separating from said ghost-cancellation reference signals said first component ghost-cancellation reference signal and said second component ghost-cancellation reference signal by combining a most current one of said designated lines with at least one temporarily stored previous one of said designated lines;

a ghost cancellation filter and an equalization filter connected in cascade for responding to said digitized baseband signal, each filter having adjustable filtering weights; and

filter weight computation circuitry, for determining said adjustable filtering weights of said ghost cancellation filter responsive to said first component ghost-cancellation reference signal separated by said separator circuitry, and for determining said adjustable filtering weights of said equalization filter responsive to said second component ghost-cancellation reference signal separated by said separator circuitry.

69. The receiver of claim 68, further characterized in that said filter weight computation circuitry comprises:

a ghost cancellation filter weight computer responding to said first component ghost-cancellation reference signals separated by said combining circuitry to determine said adjustable filtering weights of said ghost cancellation filter; and

an equalization filter weight computer responding to said second component ghost-cancellation reference signals separated by said combining circuitry to determine said adjustable filtering weights of said equalization filter.

70. The receiver of claim 69, further characterized in that said ghost cancellation filter weight computer is arranged to calculate a discrete Fourier transform (DFT) in response to said first component ghost-cancellation reference signal separated by said combing circuitry and determines said adjustable filtering weights of the ghost cancellation filter from that DFT.

71. The receiver of claim 68, further characterized in that said combining circuitry is of a type for separating said first component ghost-cancellation reference signals and said second component ghost-cancellation reference signals by combining an even number, at least four, of said designated lines.

72. A receiver as set forth in claim 68, further characterized in that in each of said ghost-cancellation reference signals said first component ghost-cancellation reference signal precedes said second component ghost-cancellation reference signal.

73. The receiver of claim 72, further characterized in that said filter weight computation circuitry comprises:

a ghost cancellation filter weight computer responding to said first component ghost-cancellation reference signals separated by said combining circuitry to determine said adjustable filtering weights of said ghost cancellation filter; and

an equalization filter weight computer responding to said second component ghost-cancellation reference signals separated by said combining circuitry to determine said adjustable filtering weights of said equalization filter.

74. The receiver of claim 73, further characterized in that said ghost cancellation filter weight computer responds to said first component ghost-cancellation reference signals separated by said combining circuitry to calculate a discrete Fourier transform (DFT) therefrom and determines said adjustable filtering weights of the ghost cancellation filter from that DFT.

75. The receiver of claim 72, further characterized in that said combining circuitry is of a type for separating said first component ghost-cancellation reference signals and said second component ghost-cancellation reference signals by combining an even number, at least four, of said designated lines.

76. The receiver of claim 68, further characterized in that each said second component ghost-cancellation reference signal comprises a pseudo-noise (PN) sequence of a prescribed first length.

77. The receiver of claim 76, further characterized in that said filter weight computation circuitry comprises:

a ghost cancellation filter weight computer responding to said first component ghost-cancellation reference signals separated by said combining circuitry to determine said adjustable filtering weights of said ghost cancellation filter; and

an equalization filter weight computer responding to said second component ghost-cancellation reference signals separated by said combining circuitry to determine said adjustable filtering weights of said equalization filter.

78. The receiver of claim 77, further characterized in that said ghost cancellation filter weight computer responds to said first component ghost-cancellation reference signals separated by said combining circuitry to calculate a discrete Fourier transform (DFT) therefrom and determines said adjustable filtering weights of the ghost cancellation filter from that DFT.

79. The receiver of claim 76, further characterized in that said combining circuitry is of a type for separating said first component ghost-cancellation reference signals and said second component ghost-cancellation reference signals by combining an even number, at least four, of said designated lines.

80. A television receiver for detecting and processing television signals transmitted in a succession of frames, each of said frames comprising an odd-numbered field followed by an even-numbered field, each of said fields comprising a specified number of line s with at least one of said lines being designated to carry a ghost-cancellation reference signal comprising a first component ghost-cancellation reference signal and a second component ghost-cancellation reference signal, said television receiver comprising:

an input for collecting said television signals, wherein said television signals include video signals and said ghost-cancellation reference signals;

an analog to digital converter coupled to said input for digitizing said video signals and said ghost-cancellation reference signals collected by said input;

a signal capture processor coupled to said analog to digital converter for receiving said digitized ghost-cancellation reference signals and for separating said first component ghost-cancellation reference signal from said second component ghost-cancellation reference signal;

a ghost-cancellation filter weight computer coupled to said signal capture processor for receiving said first component ghost-cancellation reference signal and for responding to said first component ghost-cancellation reference signal to determine a first set of adjustable filtering weights; and

an adjustable ghost-cancellation filter coupled to said analog to digital converter for receiving said digitized video signals and also coupled to said ghost-cancellation filter weight computer for receiving said first set of adjustable filtering weights, said adjustable ghost-cancellation filter processing said digitized video signals in response to said first set of adjustable filtering weights.

81. The television receiver of claim 80 further comprising:

an equalization filter weight computer coupled to said signal capture processor for receiving said second component ghost-cancellation reference signal and for responding to said second component ghost-cancellation reference signal to determine a second set of adjustable filtering weights; and

an adjustable equalization filter coupled in cascade with said adjustable ghost cancellation filter and also coupled to said equalization filter weight computer for receiving said second set of adjustable filtering weights, said adjustable equalization filter processing signals output by said adjustable ghost cancellation filter in response to said second set of adjustable filtering weights.

82. The television receiver of claim 80 further characterized in that said second component ghost-cancellation reference signal is of shorter duration than said first component ghost-cancellation reference signal.

83. The television receiver of claim 82 further characterized in that said second component ghost-cancellation reference signal is a pseudo-noise (PN) sequence.

84. The television receiver of claim 83 further characterized in that said first component ghost-cancellation reference signal is of the same amplitude and sense of polarity in both said odd-numbered field and said even-numbered field of each said frame, and said second component ghost-cancellation reference signal is the same in amplitude in both said odd numbered field and said even-numbered field of each said frame but opposite in sense of polarity.

85. The television receiver of claim 84 further comprising:

an equalization filter weight computer coupled to said signal capture processor for receiving said second component ghost-cancellation reference signal and for responding to said second component ghost-cancellation reference signal to determine a second set of adjustable filtering weights; and

an adjustable equalization filter coupled in cascade with said adjustable ghost cancellation filter and also coupled to said equalization filter weight computer for receiving said second set of adjustable filtering weights, said adjustable equalization filter processing signals output by said adjustable ghost cancellation filter in response to said second set of adjustable filtering weights.

86. A television receiver for detecting and processing television signals transmitted in a succession of frames, each of said frames comprising an odd-numbered field followed by an even-numbered field, each of said fields comprising a specified number of line with at least one of said lines being designated to carry a ghost-cancellation reference signal comprising a first component ghost-cancellation reference signal and a second component ghost-cancellation reference signal, said television receiver comprising:

an analog-to-digital converter for digitizing said analog baseband signal to generate a digital baseband signal including digitized ghost-cancellation reference signals;

adaptive digital filtering circuitry with adjustable filtering weights, said adaptive digital filtering circuitry connected for receiving as an input signal thereof said digital baseband signal as supplied from said analog-to-digital converter with any accompanying multi-path distortion and for supplying as an output signal therefrom said digital baseband signal with reduction of any accompanying multi-path distortion;

a signal capture processor connected for receiving said digital baseband signal from said analog-to-digital converter, for retrieving said first component ghost-cancellation reference signal from said digital baseband signal, and for retrieving said second component ghost-cancellation reference signal from said digital baseband signal; and

filter weight computation circuitry, for determining said adjustable filtering weights of said adaptive digital filtering circuitry responsive to at least one of said first and said second component ghost-cancellation reference signals.

87. The television receiver of claim 86, wherein said adaptive digital filtering circuitry comprises the cascade connection of:

a first adaptive digital filter; and

a second adaptive digital filter, said first adaptive digital filter having a first set of said adjustable filtering weights; and

wherein said filter weight computation circuitry is of a type for determining said first set of said adjustable filtering weights responsive to said first component ghost-cancellation reference signal.

88. The television receiver of claim 87, wherein said first adaptive digital filter is operable as a ghost-cancellation filter.

89. The television receiver of claim 87, wherein said second adaptive digital filter has a second set of said adjustable filtering weights;

and wherein said filter weight computation circuitry is of a type for determining said second set of said adjustable filtering weights responsive to said second component ghost-cancellation reference signal.

90. The television receiver of claim 89, wherein said first adaptive digital filter is operable as a ghost-cancellation filter and said second adaptive digital filter is operable as an equalization filter.

91. The television receiver of claim 90, wherein said first adaptive digital filter precedes said second adaptive digital filter in their said cascade connection.

92. The television receiver of claim 90, wherein said second component ghost-cancellation reference signal is of shorter duration than said first component ghost-cancellation reference signal.

93. The television receiver of claim 90, wherein said second component ghost-cancellation reference signal is a pseudo-noise (PN) sequence.

94. The television receiver of claim 90, wherein said first component ghost-cancellation reference signal is of the same amplitude and sense of polarity in both said odd-numbered field and said even-numbered field of each said frame, and said second component ghost-cancellation reference signal is the same in amplitude in both said odd-numbered field and said even-numbered field of each said frame but opposite in sense of polarity.

95. The television receiver of claim 86, wherein said adaptive digital filtering comprises the cascade connection of:

a first adaptive digital filter; and

a second adaptive digital filter, said second adaptive digital filter having a respective set of said adjustable filtering weights; and

wherein said filter weight computation circuitry is of a type for determining said adjustable filtering weights of said second adaptive digital filter responsive to said second component ghost-cancellation reference signal.

96. The television receiver of claim 95, wherein said second adaptive digital filter is operable as an equalization filter.

97. The television receiver of claim 96, wherein said first adaptive digital filter precedes said second adaptive filter in their said cascade connection.

98. A receiver comprising:

detection circuitry for recovering a digitized baseband signal by detecting a transmitted signal having a succession of frames, each of said frames comprising an odd-numbered field followed by an even-numbered field, each of said fields comprising a specified number of lines with only a particular one of said lines being designated to carry a respective transmission equalization reference signal comprising a first component transmission equalization reference signal and a second component transmission equalization reference signal, said first component transmission equalization reference signals being of the same amplitude and sense of polarity in both said odd-numbered field and said even-numbered field of each said frame, said second component transmission equalization reference signals being pseudo-noise (PN) sequences and being the same in amplitude in both said odd-numbered field and said even-numbered field of each said frame but opposite in sense of polarity;

circuitry for separating from said digitized baseband signal said lines designated for carrying a respective transmission equalization reference signal;

retrieving circuitry for retrieving either of said first component or second component transmission equalization reference signal from said lines designated for carrying said respective transmission equalization reference signal;

an equalization filter with adjustable filtering weights, said equalization filter connected for responding to said digitized baseband signal; and

an equalization weight computer responding to either of said first component or said second component transmission equalization reference signal retrieved by said retrieving circuitry to determine said adjustable filtering weights of the equalization filter.

99. A receiver comprising:

circuitry for recovering a digitized baseband signal by detecting a television signal having a succession of frames, each of said frames comprising an odd-numbered field followed by an even-numbered field, each of said fields comprising a specified number of lines only a particular one of which said lines is designated for carrying a respective ghost-cancellation reference signal comprising a first component ghost-cancellation reference signal and a second component ghost-cancellation reference signal, said first component ghost-cancellation reference signals being of the same amplitude and sense of polarity in both said odd-numbered field and said even-numbered field of each said frame, said second component ghost-cancellation reference signals being pseudo-noise (PN) sequences and being the same in amplitude in both said odd-numbered field and said even-numbered field of each said frame but opposite in sense of polarity;

circuitry for separating from said digitized baseband signal said lines designated for carrying a ghost-cancellation reference signal;

retrieving circuitry for retrieving either of said first component or said second component ghost-cancellation reference signal from said lines designated for carrying said ghost-cancellation reference signal;

an equalization filter with adjustable filtering weights, said equalization filter connected for responding to said digitized baseband signal; and

an equalization weight computer responding to either of said first component or said second component ghost-cancellation reference signal retrieved by said retrieving circuitry to determine said adjustable filtering weights of the equalization filter.

100. A television receiver for detecting and processing television signals transmitted in a succession of frames, each of said frames comprising an odd-numbered field followed by an even-numbered field, each of said fields comprising a specified number of lines with at least one of said lines being designated to carry a ghost-cancellation reference signal comprising a first component ghost-cancellation reference signal and a second component ghost-cancellation reference signal, said television receiver comprising:

an input for collecting said television signals, wherein said television signals include video signals and said ghost-cancellation reference signals;

an analog to digital converter coupled to said input for digitizing said video signals and said ghost-cancellation reference signals collected by said input;

a signal capture processor coupled to said analog to digital converter for receiving said digitized ghost-cancellation reference signals and for retrieving said first component ghost-cancellation reference signal from said designated one of said lines;

a ghost-cancellation filter weight computer coupled to said signal capture processor for receiving said first component ghost-cancellation reference signal and for responding to said first component ghost-cancellation reference signal to determine a first set of adjustable filtering weights; and

an adjustable ghost-cancellation filter coupled to said analog to digital converter for receiving said digitized video signals and also coupled to said ghost-cancellation filter weight computer for receiving said first set of adjustable filtering weights, said adjustable ghost-cancellation filter processing said digitized video signals in response to said first set of adjustable filtering weights.

101. The television receiver of claim 100 further characterized in that said second component ghost-cancellation reference signal is of shorter duration than said first component ghost-cancellation reference signal.

102. The television receiver of claim 101 further characterized in that said second component ghost-cancellation reference signal is a pseudo-noise (PN) sequence.

103. The television receiver of claim 102 further characterized in that said first component ghost-cancellation reference signal is of the same amplitude and sense of polarity in both said odd-numbered field and said even-numbered field of each said frame, and said second component ghost-cancellation reference signal is the same in amplitude in both said odd-numbered field and said even-numbered field of each said frame but opposite in sense of polarity.