Multiple signal transmission method and system, particularly for television
First Claim
1. A method for scrambling a plurality of input signals for secure transmission thereof comprising the steps of:
- modulating an in-phase component of at least one carrier signal in response to one and then another of the plurality of input signals in a sequence of time intervals such that parts but not all of said one and another of the input signals are carried by said in-phase component;
modulating a quadrature component of said at least one carrier signal in response to said one and then said another of said plurality of input signals in said sequence of time intervals such that parts but not all of said one and another input signals are carried by said quadrature component and such that said in-phase and quadrature components together carry said two input signals in their entireties; and
,combining said modulated in-phase and quadrature components for transmission.
3 Assignments
0 Petitions
Accused Products
Abstract
A method and system for scrambling a plurality of input signals for secure transmission thereof, as well as various methods and systems for television transmission, are disclosed. The disclosed scrambling technique, in one form, includes modulating an in-phase component of at least one carrier signal in response to one and then another of a plurality of input signals in a sequence of time intervals such that parts but not all of the one and another of the input signals are carried by the in-phase component. A quadrature component of the at least one carrier signal is modulated in response to the one and another of the plurality of input signals in the sequence of time intervals such that parts but not all of the one and another of the input signals are carried by the quadrature component and such that the in-phase and quadrature components together carry the one and another of the input signals in their entireties. The modulated in-phase and quadrature components are combined for transmission. A decoder for unscrambling the plurality of signals is also disclosed. The various television transmission methods and systems involve provision of additional audio signals, in scrambled or unscrambled form, with the normal television audio and video signals so that multi-lingual program service as well as other services can be provided.
189 Citations
62 Claims
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1. A method for scrambling a plurality of input signals for secure transmission thereof comprising the steps of:
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modulating an in-phase component of at least one carrier signal in response to one and then another of the plurality of input signals in a sequence of time intervals such that parts but not all of said one and another of the input signals are carried by said in-phase component; modulating a quadrature component of said at least one carrier signal in response to said one and then said another of said plurality of input signals in said sequence of time intervals such that parts but not all of said one and another input signals are carried by said quadrature component and such that said in-phase and quadrature components together carry said two input signals in their entireties; and
,combining said modulated in-phase and quadrature components for transmission. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of operating a television system comprising the steps of:
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transmitting a television audio program signal and a television video program signal within respective normal television audio and video signal frequency bands of an overall television frequency band allocated for transmission of a single television channel, said audio and video program signals being transmitted at respective normal audio and normal video center frequencies assigned for normal transmission of the respective audio and video signals within said normal television audio and video frequency bands; simultaneously transmitting at least two additional user selectable audio signals within said overall television frequency band at at least one center frequency lying within the television audio frequency band, said at least one center frequency being displaced from the normal audio center frequency by an amount such that, in the transmission thereof, the two additional audio signals at said at least one center frequency do not interfere with the television audio or video program signals and do not exceed the limits of the overall television frequency band. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A method for transmitting television audio and video program signals comprising the steps of:
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providing at least two different audio signals and at least one television video program signal, at least one of the audio signals being a television audio program signal associated with the television video program signal; transmitting the video program signal in a first frequency band; transmitting in a first form within a second frequency band one and then the other of the audio signals in a sequence of time intervals such that parts but not all of each of the two audio signals are transmitted in the second frequency band in the first form; transmitting within said second frequency band, in a second form distinguishable from said first form, one and then the other of the audio signals in said sequence of time intervals such that the one of the audio signals is transmitted in a time interval in the second form while the other is being transmitted in a time interval of corresponding length in the first form and vice-versa, parts of the one and the other audio signals not transmitted in the first form thereby being transmitted in the second form so that the two audio signals are transmitted in their entireties in the second frequency band but are transmitted in part in the first form and in part in the second form, both of the two audio signals being available in the transmitted signal for selection in their entireties from said first and second forms. - View Dependent Claims (40, 41, 42, 43, 44, 45, 46)
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19. A method for operating a subscription television system comprising the steps of:
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transmiting a scrambled television video signal within a first frequency band together with both an unscrambled audio signal and a plurality of scrambled audio signals within a second frequency band, the first and second frequency bands being within an overall frequency band allocated to a single television channel; receiving the transmitted first and second frequency bands containing the scrambled video signal, the unscrambled audio signal and the plurality of scrambled audio signals; selectively displaying a scrambled or an unscrambled television video signal in response to the received scrambled television video signal in the first frequency band; selectively producing audio with the displayed scrambled television video signal in response to the received unscrambled audio signal in the second frequency band and producing audio with the displayed unscrambled television video signal in response to a selected one of the plurality of scrambled audio signals in the received second frequency band.
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20. Apparatus for scrambling a plurality of input signals for secure transmission thereof comprising:
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means for generating an in-phase and a quadrature component of at least one carrier signal; means for modulating the in-phase component of said at least one carrier signal in response to one and then another of the plurality of input signals in a sequence of time intervals such that parts but not all of said one another of the input signals are carried by said in-phase component; means for modulating the quadrature component of said at least one carrier signal in response to said one and then said another of said plurality of input signals in said sequence of time intervals such that parts but not all of said one and another input signals are carried by said quadrature component and such that said in-phase and quadrature components together carry said two input signals in their entireties; and
,means for combining said modulated in-phase and quadrature components for transmission. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29)
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- 30. In a television transmission system including means for transmitting a television audio and video program signals within respective normal television audio and video signal frequency band of an overall television frequency band allocated for transmission of a single television channel, wherein said audio and video program signal are transmitted at a normal audio and video center frequencies assigned for normal transmission of the respective audio and video signals within said normal television audio and video frequency bands, the improvement comprising means for simultaneously transmitting at least two additional user selectable audio signals within said overall television frequency band at at least one center frequency lying within said television audio frequency band, said at least one center frequency being displaced from said normal audio center frequency by an amount such that, in the transmission thereof, the two additional audio signals at said at least one center frequency do not interfere with the television audio or video program signals and do not exceed the limits of the overall television frequency band.
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35. A television audio and video program signal transmission system comprising:
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first and second sources for at least two different audio signals and a third source for at least one television video program signal, at least one of the audio signals being a television audio program signal associated with the television video program signal; first transmitting means for transmitting the video program signal in a first frequency band; second transmitting means for transmitting in a first form within a second frequency band one and then the other of the audio signals in a sequence of time intervals such that parts but not all of each of the two audio signals are transmitted in the second frequency band in the first form, said second transmitting means including means for transmitting within said second frequency band, in a second form distinguishable from said first form, one and then the other of the audio signals in said sequence of time intervals such that the one of the audio signals is transmitted in a time interval in the second form while the other is being transmitted in a time interval of corresponding length in the first form and vice-versa, parts of the one and the other audio signals not transmitted in the first form thereby being transmitted in the second form so that the two audio signals are transmitted in their entireties in the second frequency band but are transmitted in part in the first form and in part in the second form, both of the two audio signals being available in the transmitted signal from said second transmitting means for selection in their entireties from said first and second forms. - View Dependent Claims (36, 37, 38)
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39. A subscription television system comprising:
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means for transmitting a scrambled television video signal within a first frequency band together with both an unscrambled audio signal and a plurality of scrambled audio signals within a second frequency band, the first and second frequency bands being within an overall frequency band allocated to a single television channel; means for receiving the transmitted first and second frequency bands containing the scrambled video signal, the unscrambled audio signal and the plurality of scrambled audio signals; means for selectively displaying a scrambled or an unscrambled television video signal in response to the received scrambled television video signal in the first frequency band; and
,means for selectively producing audio with the displayed scrambled television video signal in response to the received unscrambled audio signal in the second frequency band and producing audio with the displayed unscrambled television video signal in response to a selected one of the plurality of scrambled audio signals in the received second frequency band.
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47. A method of operating a television system comprising the steps of:
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transmitting from a first location, a television audio and video program signal and at least two additional audio program signals associated with the television video signal so that the television video signal is transmitted with at least three associated audio program signals each containing information relating to the video content of the video signal, the television audio and video program signal and the at least two additional audio program signals being transmitted within a frequency band allocated to a single television channel each in a form distinguishable from the others; receiving at a location remote from the one location, the transmitted television audio and video program signals and the at least two additional audio program signals and selecting at least one of the three audio program signals for production of sound with the video signal. - View Dependent Claims (48, 49)
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50. A television system comprising:
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means at a first location for transmitting a television audio and video program signal and at least two additional audio program signals associated with the television video signal such that the television video signal is transmitted with at least three associated audio program signals each containing information relating to the video content of the video signal, said transmitting means transmitting the television audio and video program signal and the at least two additional audio program signals within a frequency band allocated to a single television channel each in a form distinguishable from the other; and
,means at a location remote from the first location for receiving the television audio and video program signal and the at least two additional audio program signals transmitted from the first location and selecting at least one of the three audio program signals for production of sound with the video signal. - View Dependent Claims (51, 52, 53, 54)
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55. A method for transmitting and receiving information in a television system comprising the steps of:
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providing a television video program signal, a television audio program signal and a plurality of information signals, the information signals each being limited in frequency to a predetermined audio frequency range; generating a plurality of distinctive carrier signals within a predetermined frequency band allocated for transmission of audio to a single television channel; modulating a first one of the plurality of carrier signals with at least one of the plurality of information signals; modulating a second of the plurality of carrier signals with at least another of the plurality of information signals; combining the audio program signal and the modulated first and second carrier signals to form a composite baseband audio signal; transmitting the video program signal and the composite baseband audio signal at carrier frequencies within respective video and audio frequency bands allocated to a single television channel for transmission of video and audio; detecting the composite baseband audio signal in the transmitted signal; and selecting any of the audio program signal and the plurality of information signals from the detected composite baseband audio signal as a useable output signal. - View Dependent Claims (56, 57, 58, 61)
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59. Apparatus for transmitting and receiving information in a television system comprising:
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means for providing a television video program signal, a television audio program signal and a plurality of information signals, the information signals each being limited in frequency to a predetermined audio frequency range; means for generating a plurality of distinctive carrier signals within a predetermined frequency band allocated for transmission of audio to a single television channel; means for modulating a first and a second of the plurality of carrier signals with at least one and another, respectively, of the plurality of information signals; means for combining the audio program signal and the modulated first and second carrier signals to form a composite baseband audio signal; means for transmitting the video program signal and the composite baseband audio signal at carrier frequencies within respective video and audio frequency bands allocated to a single televison channel for transmission of video and audio; and means remote from the transmitting means for detecting the composite baseband audio signal in the transmitted signal and selecting any of the audio program signal and the plurality of information signals from the detected composite baseband audio signal as a useable output signal. - View Dependent Claims (60, 62)
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Specification