Subband coded digital transmission system using some composite signals
DC CAFCFirst Claim
1. A digital transmission system, for producing a replica of a digital signal comprising at least a first component and a second component, comprising:
- an encoder including analysis means for altering said digital signal to obtain a plurality of sub-signals, including at least a first sub-signal and a second sub-signal from said first component and said second component respectively,signal combination means for combining said first sub-signal and said second sub-signal to obtain a composite sub-signal,signal generator means for generating an indicator signal indicating that said first sub-signal and said second sub-signal are combined,transmission means for transmitting said indicator signal, said composite sub-signal, and sub-signals which have not been combined,receiving means for receiving the signals which were transmitted,means, responsive to the received indicator signal and composite subsignal, for generating a signal related to at least one of said first component and said second component, anda decoder including synthesis means for combining the transmitted subsignals and the signal related to at least one of said first component and said second component to produce said replica of the digital signal.
2 Assignments
Litigations
1 Petition
Accused Products
Abstract
Reproduction accuracy of, for example a digital stereo audio signal, is improved by transmitting sample data as sub-signals such as frequency subband signals. In one or more subbands, corresponding components such as left and right stereo channels are combined so that only one composite signal is transmitted per subband. An indicator signal is transmitted, indicating which subbands are combined. Scale factor signals for all subbands, and for the relative intensity of the respective subband signals which were combined, may also be transmitted. In the receiver a subband signal is derived for each channel from the composite signal, before synthesis of the full channel signals which will be reproduced.
225 Citations
22 Claims
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1. A digital transmission system, for producing a replica of a digital signal comprising at least a first component and a second component, comprising:
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an encoder including analysis means for altering said digital signal to obtain a plurality of sub-signals, including at least a first sub-signal and a second sub-signal from said first component and said second component respectively, signal combination means for combining said first sub-signal and said second sub-signal to obtain a composite sub-signal, signal generator means for generating an indicator signal indicating that said first sub-signal and said second sub-signal are combined, transmission means for transmitting said indicator signal, said composite sub-signal, and sub-signals which have not been combined, receiving means for receiving the signals which were transmitted, means, responsive to the received indicator signal and composite subsignal, for generating a signal related to at least one of said first component and said second component, and a decoder including synthesis means for combining the transmitted subsignals and the signal related to at least one of said first component and said second component to produce said replica of the digital signal. - View Dependent Claims (2, 3, 11)
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4. A digital transmission system, for producing a replica of a digital signal comprising at least a first and a second component, comprising a transmitter and a receiver,
wherein said transmitter comprises: -
an encoder including analysis means for filtering said digital signal to obtain subband signals for M subbands, where M>
1, said subband signals including a plurality of first subband signals and a plurality of second subband signals from said first component and second component respectively,signal combination means for combining m1 of said first subband signals respectively with m1 of said second subband signals from corresponding subbands to obtain m1 composite subband signals, where 1<
m1 <
M,signal generator means for generating an indicator signal indicating which said first and second subband signals are combined, and transmission means for transmitting said indicator signal, said composite subband signals, and subband signals which were not combined, and the receiver comprises; receiving means for receiving the signals which have been transmitted, detection means for detecting said indicator signal, derivation means responsive to the received indicator signal, for producing, from the received composite subband signals, derived subband signals related to m1 of said first subband signals and m1 of said second subband signals, and a decoder including synthesis means for combining said derived subband signals and the received subband signals which were not combined, to produce said replica of the digital signal. - View Dependent Claims (5, 6, 7, 8, 9, 10)
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12. A transmitter, for transmitting signals representative of a digital signal comprising at least a first component and a second component, over a transmission medium, comprising:
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an encoder including analysis means for altering said digital signal to obtain a plurality of sub-signals, including at least a first sub-signal and a second sub-signal from said first component and said second component respectively, signal combination means for combining said first sub-signal and said second sub-signal to obtain a composite sub-signal, signal generator means for generating an indicator signal indicating that said first sub-signal and said second sub-signal are combined, transmission means for transmitting said indicator signal, said composite sub-signal, and sub-signals which have not been combined. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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19. A receiver for producing a replica of a digital signal including a first component and a second component, from digital signal components comprising at least one composite sub-signal, an indicator signal indicating that at least a first and a second sub-signal are combined, and a plurality of subsignals not including said first and second sub-signal, said digital signal components being representative of said digital signal,
receiving means for receiving said digital signal components, means, responsive to the received indicator signal and composite subsignal, for generating a signal related to at least one of said first component and said second component, and a decoder including synthesis means for combining the transmitted subsignals and the signal related to at least one of said first component and said second component to produce said replica of the digital signal.
Specification