US4484336A
Expired / Lapsed
US
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Digital transmission systems
Assignee: STC PLC
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Filing: 1982-05-21
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Granted: 1984-11-20
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Expires: 2002-05-21
Abstract
Abstract Feedback equalization is employed for digital repeaters of transmission systems having twisted-wire pairs, in order to reduce intersymbol interference while minimizing near-end crosstalk gain. Previously the incoming signal was selectively amplified at the higher frequencies in order to negate intersymbol interference, with subsequent near-end crosstalk gain. According to the present invention the intersymbol interference element of an incoming signal is cancelled, prior to amplification in an adder by a compensation signal derived from the output signal of a regenerator and a retimer. An output stage serves to amplify and shape the resultant signal to a form suitable for transmission. The compensation signal comprises the inverted output of a filtering and scaling network.
Inventors
- 👤 Richard J. Catchpole
- 👤 Peter J. Dyke
- 👤 Brian S. Farley
- 👤 Harbhajan S. Virdee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:12
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/62; H04B1/64; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03012; H04L25/03019
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
172 words
A digital transmission system comprising: a twisted-wire pair transmission line; and at least one digital repeater coupled to said transmission line having an arrangement to reduce intersymbol interference in an incoming signal while minimizing near-end crosstalk gain, said arrangement including a pulse regenerator and a retimer network having an input and an output, an adder having two inputs and an output, a feedback network coupled to said output of said regenerator and retimer network to produce a compensation signal, said compensation signal being coupled to one of said two inputs of said adder, an additional network disposed between said output of said adder and said input of said regenerator and retimer network to provide a suitable input signal for said regenerator and retimer network, a filter network coupling said incoming signal to the other of said two inputs of said adder, and a control network coupled to said input of said regenerator and retimer network and at least a selected one of said feedback network, said additional network and said filter network.
Claim 2
Dependent Claim
172 words
A digital transmission system comprising: a twisted-wire pair transmission line; and at least one digital repeater coupled to said transmission line having an arrangement to reduce intersymbol interference in an incoming signal while minimizing near-end crosstalk gain, said arrangement including a pulse regenerator and a retimer network having an input and an output, an adder having two inputs and an output, a feedback network coupled to said output of said regenerator and retimer network to produce a compensation signal, said compensation signal being coupled to one of said two inputs of said adder, an additional network disposed between said output of said adder and said input of said regenerator and retimer network to provide a suitable input signal for said regenerator and retimer network, a filter network coupling said incoming signal to the other of said two inputs of said adder, and a control network coupled to said input of said regenerator and retimer network and at least a selected one of said feedback network, said additional network and said filter network.
Claim 3
Dependent Claim
51 words
A system according to claim 1, wherein said repeater further includes an output network coupled to said output of said regenerator and retimer network to form a signal suitable for transmission on said transmission line and to buffer said feedback network from the effects of the impedance of said transmission line.
Claim 4
Dependent Claim
156 words
A digital repeater for use with a twisted-pair transmission line to reduce intersymbol interference in an incoming signal while minimizing near-end crosstalk gain comprising: a pulse regenerator and a retimer network having an input and an output, an adder having two inputs and an output, a feedback network coupled to said output of said regenerator and retimer network to produce a compensation signal, said compensation signal being coupled to one of said two inputs of said adder, an additional network disposed between said output of said adder and said input of said regenerator and retimer network to provide a suitable input signal for said regenerator and retimer network, a filter network coupling said incoming signal to the other of said two inputs of said adder, and a control network coupled to said input of said regenerator and retimer network and at least a selected one of said feedback network, said additional network and said filter network.
Claim 5
Dependent Claim
156 words
A digital repeater for use with a twisted-pair transmission line to reduce intersymbol interference in an incoming signal while minimizing near-end crosstalk gain comprising: a pulse regenerator and a retimer network having an input and an output, an adder having two inputs and an output, a feedback network coupled to said output of said regenerator and retimer network to produce a compensation signal, said compensation signal being coupled to one of said two inputs of said adder, an additional network disposed between said output of said adder and said input of said regenerator and retimer network to provide a suitable input signal for said regenerator and retimer network, a filter network coupling said incoming signal to the other of said two inputs of said adder, and a control network coupled to said input of said regenerator and retimer network and at least a selected one of said feedback network, said additional network and said filter network.
Claim 6
Dependent Claim
47 words
A repeater according to claim 3, further including an output network coupled to said output of said regenerator and retimer network to form a signal suitable for transmission on said transmission line and to buffer said feedback network from the effects of impedance of said transmission line.
Claim 7
Dependent Claim
19 words
A system according to claim 1, wherein a control signal output of said control network controls said filter network.
Claim 8
Dependent Claim
19 words
A system according to claim 1, wherein a control signal output of said control network controls said feedback network.
Claim 9
Dependent Claim
23 words
A system according to claim 1, wherein a control signal output of said control network controls said filter network and said feedback network.
Claim 10
Dependent Claim
19 words
A system according to claim 1, wherein a control signal output of said control network controls said additional network.
Claim 11
Dependent Claim
23 words
A system according to claim 1, wherein a control signal output of said control network controls said filter network and said additional network.
Claim 12
Dependent Claim
23 words
A system according to claim 1, wherein a control signal output of said control network controls said feedback network and said additional network.
Claim 13
Dependent Claim
26 words
A system according to claim 1, wherein a control signal output of said control network controls said feedback network, said filter network and said additional network.
Claim 14
Dependent Claim
22 words
A repeater according to claim 3, wherein said output network prevents impedance variations of said transmission lines from affecting said compensation signal.
Claim 15
Dependent Claim
22 words
A repeater according to claim 3, wherein said feedback network prevents impedance variations of said transmission lines from affecting said compensation signal.
Claim 16
Dependent Claim
18 words
A repeater according to claim 3, wherein said control network has a low-pass characteristic to limit error multiplication.
Claim 17
Dependent Claim
31 words
A repeater according to claim 3, wherein said control network has a high frequency characteristic to minimize generation of pattern dependent jitter in said retimer of said regenerator and retimer network.
Claim 18
Dependent Claim
19 words
A repeater according to claim 3, wherein a control signal output of said control network controls said filter network.
Claim 19
Dependent Claim
19 words
A repeater according to claim 3, wherein a control signal output of said control network controls said feedback network.
Claim 20
Dependent Claim
23 words
A repeater according to claim 3, wherein a control signal output of said control network controls said filter network and said feedback network.
Claim 21
Dependent Claim
19 words
A repeater according to claim 3, wherein a control signal output of said control network controls said additional network.
Claim 22
Dependent Claim
23 words
A repeater according to claim 3, wherein a control signal output of said control network controls said filter network and said additional network.
Claim 23
Dependent Claim
23 words
A repeater according to claim 3, wherein a control signal output of said control network controls said feedback network and said additional network.
Claim 24
Dependent Claim
26 words
A repeater according to claim 3, wherein a control signal output of said control network controls said feedback network, said filter network and said additional network.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-20 | 1988-05-21 | 1988-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-20 | 1992-05-21 | 1992-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-20 | 1996-05-21 | 1996-11-20 | $7700.00 | Window Closed / Lapsed |