Distribution of digitized composite AM FDM signals
First Claim
1. A method of distributing signals from a head-end station via a network comprising:
- combining a plurality of AM channels modulated on sub-carriers at different frequencies to form a composite analogue signal, treating the composite analogue signal to reduce the peak-to-mean ratio,digitizing the composite analogue signal,transmitting resulting digital data onto the network, andreceiving the digital data at a receiver and reconstituting the composite analogue signal for reception at a termination.
1 Assignment
0 Petitions
Accused Products
Abstract
Signals, such as television signals, are distributed from a head-end station via a fibre network. The signals are amplitude modulated on carriers at different frequencies, and the different carriers combined to form a composite analogue signal. In the head-end station the composite analogue signal is clipped to reduce the peak-to-mean ratio and the clipped composite signal is digitized. The resulting digital data is transmitted onto the fibre network and is received at an optical receiver. The optical receiver reconstitutes the composite analogue signal for reception by a termination. In one example the composite analogue signal has a bandwidth of one octave or less, and is digitized by sampling at a sampling rate below the Nyquist rate.
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Citations
18 Claims
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1. A method of distributing signals from a head-end station via a network comprising:
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combining a plurality of AM channels modulated on sub-carriers at different frequencies to form a composite analogue signal, treating the composite analogue signal to reduce the peak-to-mean ratio, digitizing the composite analogue signal, transmitting resulting digital data onto the network, and receiving the digital data at a receiver and reconstituting the composite analogue signal for reception at a termination. - View Dependent Claims (2, 3, 4, 5)
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6. A method of distributing signals from a head-end station via a network comprising:
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combining a plurality of AM channels modulated on sub-carriers at different frequencies to form a composite analogue signal, treating the composite analogue signal to reduce the peak-to-mean ratio, digitizing the composite analogue signal, transmitting resulting digital data onto the network, and receiving the digital data at a receiver and reconstituting the composite analogue signal for reception at a termination, the composite analogue signal having a bandwidth of one octave or less and being digitized by sampling at a sampling rate below the Nyquist rate. - View Dependent Claims (7, 8, 9)
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10. A system for distributing signals comprising:
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a head-end station, one or more receivers, a network connecting the head-end station to the or each receiver, the head-end station including an input stage arranged to receive a composite analogue signal comprising a plurality of AM channels modulated on sub-carriers at different frequencies, converter means arranged to treat the composite analogue signal to reduce the peak-to-mean ratio and to digitize the composite analogue signal, and transmitter means arranged to transmit the resulting digital data onto the network, and the receiver including reconstituting means arranged to reconstitute the composite analogue signal and output means arranged to output the composite analogue signal for reception by a termination. - View Dependent Claims (11, 12, 13)
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14. A system for distributing signals comprising:
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a head-end station, one or more receivers, a network connecting the head-end station to the or each receiver, the head-end station including an input stage arranged to receive a composite analogue signal comprising a plurality of AM channels modulated on sub-carriers at different frequencies, converter means arranged to treat the composite analogue signal to reduce the peak-to-mean ratio and to digitize the composite analogue signal, and transmitter means arranged to transmit the resulting digital data onto the network, and the receiver including reconstituting means arranged to reconstitute the composite analogue signal and output means arranged to output the composite analogue signal for reception by a termination, the composite analogue signal having a bandwidth of one octave or less and the converter means being arranged to sample the composite analogue signal at a sampling rate below the Nyquist rate. - View Dependent Claims (15, 16, 17, 18)
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Specification