Apparatus for transmitting auxiliary signal in a TV channel
First Claim
1. Apparatus for frequency interleaving an auxiliary signal with a television signal, said auxiliary signal having a substantially continuous frequency bandwidth which is greater than a multiple of the horizontal line frequency of said video signal, said apparatus comprising:
- means for providing said auxiliary signal and said video signal;
means for providing a horizontal synchronizing signal related to said video signal;
means including means, responsive to said auxiliary signal and said horizontal synchronizing signal, for apportioning said auxiliary signal to generate first and second signals each of which includes a mutually exclusive portion of said auxiliary signal, and includes polarity inverted portions of said auxiliary signal;
means responsive to said first and second signals and said horizontal synchronizing signal for generating a quadrature phase modulated signal; and
means for combining said quadrature phase modulated signal with said video signal.
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Accused Products
Abstract
Apparatus for converting a signal having a substantially continuous frequency spectrum to a signal having its energy concentrated at multiples of the line frequency of a video signal, includes circuitry for apportioning the signal into two intermediate signals including, in part, mutually exclusive portions of the original signal and inverting the polarity of portions of the signal. The two intermediate signals are thereafter used to quadrature phase modulate a carrier of multiple line frequency to generate a signal for combining with a video signal for transmission.
139 Citations
16 Claims
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1. Apparatus for frequency interleaving an auxiliary signal with a television signal, said auxiliary signal having a substantially continuous frequency bandwidth which is greater than a multiple of the horizontal line frequency of said video signal, said apparatus comprising:
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means for providing said auxiliary signal and said video signal; means for providing a horizontal synchronizing signal related to said video signal; means including means, responsive to said auxiliary signal and said horizontal synchronizing signal, for apportioning said auxiliary signal to generate first and second signals each of which includes a mutually exclusive portion of said auxiliary signal, and includes polarity inverted portions of said auxiliary signal; means responsive to said first and second signals and said horizontal synchronizing signal for generating a quadrature phase modulated signal; and means for combining said quadrature phase modulated signal with said video signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. Apparatus for frequency interleaving an auxiliary signal with a television signal, said auxiliary signal having a substantially continuous frequency bandwidth which is greater than a multiple of the horizontal line frequency of said video signal, said apparatus comprising:
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means for providing said auxiliary signal and said video signal; means for providing a horizontal synchronizing signal related to said video signal; means responsive to said horizontal synchronizing signal for generating first and second operating signals having a 90 degree phase relationship and a frequency which is an odd multiple, including one of one-fourth of said horizontal line frequency; first and second multiplying means responsive to said first and second operating signals, for multiplying said auxiliary signal; a first subtractive comb filter coupled to an output of said first multiplying means for providing a first signal; and a second subtractive comb filter coupled to an output of said second multiplying means for providing a second signal; means responsive to said first and second signals and said horizontal synchronizing signal for generating a quadrature phase modulated signal; and means for combining said quadrature phase modulated signal with said video signal.
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9. Apparatus for converting the frequency spectrum of an auxiliary signal having a substantially continuous frequency bandwidth, to a frequency spectrum wherein its signal energy is concentrated at odd multiples of one-half the line frequency of a video signal, said apparatus comprising:
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means for providing said auxiliary signal; means for providing a video signal horizontal synchronizing signal having a frequency fH ; delay means, responsive to said auxiliary signal, for providing polarity inverted auxiliary signal delayed by an integer multiple, including one of periods equal to the reciprocal of fH ; switch means coupled for receiving said auxiliary signal and said polarity inverted delayed auxiliary signal, for providing at a first output terminal thereof, a first signal including periods of said auxiliary signal alternating with periods of said polarity inverted delayed auxiliary signal which periods correspond to said multiple of the reciprocal of fH, and for providing at a second output terminal thereof, a second signal including periods of said polarity inverted delayed auxiliary signal alternating with periods of said auxiliary signal, which periods correspond to said multiple of the reciprocal of fH ; means responsive to said horizontal synchronizing signal for generating first and second operating signals having a 90 degree phase relationship and a frequency which is a further multiple of fH ; and means responsive to said first and second signals and said first and second operating signals for generating a quadrature phase modulated signal having a carrier frequency equal to said further multiple of fH, said quadrature phase modulated signal corresponding to said auxiliary signal with signal energy concentrated at odd multiples of one-half line frequency.
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10. Apparatus for converting the frequency spectrum of an auxiliary signal having a substantially continuous frequency bandwidth, to a frequency spectrum wherein its signal energy is concentrated at odd multiples of one-half the line frequency of a video signal, said apparatus comprising:
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means for providing said auxiliary signal; means for providing a video signal horizontal synchronizing signal having a frequency fH ; means for providing a video carrier signal of frequency fP ; means responsive to said horizontal synchronizing signal for generating first and second operating signals having a 90 degree phase relationship and a frequency which is an odd multiple, including one, of one-fourth of said horizontal line frequency; first and second multiplying means responsive to said first and second operating signals, for multiplying said auxiliary signal; a first subtractive comb filter coupled to an output of said first multiplying means for providing a first information signal; a second subtractive comb filter coupled to an output of said second multiplying means for providing a second information signal; means responsive to said video carrier signal and said horizontal synchronizing signal for generating third and fourth operating signals having a 90 degree phase relationship and a frequency equal to the fP -kfH, where k is an integer; and means responsive to said first and second information signals and said third and fourth operating signals for generating a quadrature phase modulated signal, said quadrature phase modulated signal corresponding to an auxiliary carrier with its energy concentrated at multiples of half said horizontal line frequency.
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11. In a receiver for detecting combined signals including an auxiliary signal and a television signal, said auxiliary signal representing an auxiliary signal having a substantially continuous frequency spectrum but having its energy concentrated at odd half multiples of the television signal line frequency for transmission, apparatus comprising:
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means for receiving said combined signal; means responsive to said combined signal for separating said auxiliary signal; means responsive to said television signal for providing a horizontal synchronizing signal; means responsive to said horizontal synchronizing signal for providing first and second operating signals having a 90 degree phase relationship and a frequency which is a multiple of the frequency of said horizontal synchronizing signal; first and second multiplying means having respective output terminals, for respectively multiplying said auxiliary signal by said first and second operating signals; switch means having first and second output terminals and having respective input terminals coupled respectively to the output terminals of said first and second multiplying means, said switch means alternately coupling its first output terminal to the output terminals of the first and second multiplying means for horizontal line periods and alternately coupling its second output terminal to the output terminals of said second and first multiplying means for horizontal line periods; delay means coupled to the first output terminal of said switch means for delaying signal by integral horizontal line periods; and signal combining means coupled to the delay means and the second output terminal of said switch means for providing an output auxiliary signal. - View Dependent Claims (12, 13)
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14. In a receiver for detecting combined signals including an auxiliary signal and a television signal, said auxiliary signal representing an auxiliary signal having a substantially continuous frequency spectrum but having its energy concentrated at odd half multiples of the television signal line frequency for transmission, apparatus comprising:
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means for receiving said combined signal; means responsive to said television signal for providing a horizontal synchronizing signal; means for providing a video carrier signal; means responsive to said horizontal synchronizing signal and said video carrier signal for generating first, second, third and fourth operating signals of the form cos(ω
t)cos(ω
0 t), sin(ω
t)sin(w0 t), -sin(ω
t)cos(ω
0 t) and cos(ω
t)sin(0 t) respectively where ω
is an angular frequency corresponding to an odd multiple of said line frequency divided by four, and ω
0 is an angular frequency corresponding to P-kfH where P is the video carrier frequency, k is an integer and fH is said line frequency;first, second, third and fourth multiplying circuits respectively responsive to said first, second, third and fourth operating signals for respectively multiplying said received signal; first adding means for adding signals provided by said first and second multiplying circuits; second adding means for adding signals provided by said third and fourth multiplying circuits; delay means coupled to one of said first and second adding means for delaying signal by an integer multiple of the reciprocal of said line frequency; and combining means coupled to said delay means and the other of said first and second adding circuits, for providing said auxiliary signal having a substantially continuous frequency spectrum.
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15. Apparatus for decoding a vestigial sideband video signal including a sound signal and, an auxiliary digital sound signal in the vestigial sideband comprising:
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antenna and RF tuner circuitry for detecting said vestigial sideband video signal; picture IF detector and processing circuitry, coupled to said tuner circuitry for generating baseband video signals; sound IF detector and processing circuitry, coupled to said tuner circuitry for generating baseband sound signals from said sound signal included in said vestigial sideband video signal; auxiliary IF detector and processing circuitry, coupled to said tuner circuitry for generating auxiliary baseband sound signals from said auxiliary digital sound signal in the vestigial sideband sound reproduction means; and means for selectively coupling said baseband sound signals or said auxiliary baseband sound signal to said sound reproduction means. - View Dependent Claims (16)
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Specification