US5412415A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Distribution of digitized composite AM FDM signals
Assignee: British Telecommunications PLC
•
Filing: 1991-04-10
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Granted: 1995-05-02
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Expires: 2011-04-10
Abstract
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.
Inventors
- 👤 Andrew R. J. Cook
- 👤 David W. Faulkner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:15
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/22
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
72 words
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, and receiving the digital data at a receiver and reconstituting the composite analogue signal for reception at a termination.
Claim 2
Independent Claim
72 words
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, and receiving the digital data at a receiver and reconstituting the composite analogue signal for reception at a termination.
Claim 3
Dependent Claim
36 words
A method according to claim 1, in which the network is an optical network, the receiver is an optical receiver, and the composite analogue signal is treated to reduce its peak-to-mean ratio by clipping the signal.
Claim 4
Dependent Claim
29 words
A method according to claim 1, including: receiving the digitized signal at a node remote from the termination, and transmitting the reconstituted signal onwards for reception at the termination.
Claim 5
Dependent Claim
26 words
A method according to claim 1, including compressing the composite analogue signal at the head-end station and applying complementary expansion to the signal at the receiver.
Claim 6
Dependent Claim
18 words
A method according to claim 1, in which the signals distributed from the head-end station are television signals.
Claim 7
Independent Claim
97 words
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, 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.
Claim 8
Independent Claim
97 words
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, 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.
Claim 9
Dependent Claim
36 words
A method as in claim 6, in which the network is an optical network, the receiver is an optical receiver, and the composite analogue signal is treated to reduce its peak-to-mean ratio by clipping the signal.
Claim 10
Dependent Claim
29 words
A method as in claim 6 including: receiving the digitized signal at a node remote from the termination, and transmitting the reconstituted signal onwards for reception at the termination.
Claim 11
Dependent Claim
26 words
A method as in claim 6, including compressing the composite analogue signal at the head-end station and applying complementary expansion to the signal at the receiver.
Claim 12
Independent Claim
112 words
A system for distributing signals comprising: 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.
Claim 13
Independent Claim
112 words
A system for distributing signals comprising: 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.
Claim 14
Dependent Claim
35 words
A system according to claim 10, in which the network is an optical network, the receiver is an optical receiver, and the converter means are arranged to treat the composite analogue signal by clipping it.
Claim 15
Dependent Claim
37 words
A system according to claim 11, in which the or each optical receiver is located at a respective node remote from the termination and is arranged to transmit the reconstituted signal onwards for reception at the termination.
Claim 16
Independent Claim
37 words
A system according to claims 10, further including compression means located in the head-end station and expansion means located in the or each receiver and arranged to apply complementary compression and expansion to the composite analogue signals.
Claim 17
Independent Claim
144 words
A system for distributing signals comprising: 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.
Claim 18
Independent Claim
144 words
A system for distributing signals comprising: 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.
Claim 19
Dependent Claim
35 words
A system according to claim 14, in which the network is an optical network, the receiver is an optical receiver, and the converter means are arranged to treat the composite analogue signal by clipping it.
Claim 20
Dependent Claim
37 words
A system as in claim 15, in which the or each optical receiver is located at a respective node remote from the termination and is arranged to transmit the reconstituted signal onwards for reception at the termination.
Claim 21
Dependent Claim
37 words
A system as in claim 14, further including compression means located in the head-end station and expansion means located in the or each receiver and arranged to apply complementary compression and expansion to the composite analogue signals.
Claim 22
Dependent Claim
18 words
A system as in claim 14, in which the signals distributed from the head-end station are television signals.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-05-01 | 1998-10-31 | 1999-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-01 | 2002-10-31 | 2003-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-01 | 2006-10-31 | 2007-05-02 | $7700.00 | Window Closed / Lapsed |