US3898564A
Expired / Lapsed
US
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Margin monitoring circuit for repeatered digital transmission line
Assignee: AT&T Inc
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Filing: 1974-03-11
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Granted: 1975-08-05
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Expires: 1994-03-11
Abstract
Abstract The margin against the probable occurrence of errors as well as the actual occurrence of errors, is monitored in an automatically equalized repeater of a digital line of a pulse code modulation communication system. This is done while the system is in service. A model pulse stream derived from a regenerator output by use of a simulated equalized line; the previously equalized pulse stream received at the regenerator input, suitably delayed is compared with the model pulse stream in an analog subtraction circuit to produce an error signal. The error signal may then be peak-detected by a type of peak-detector capable of fast turn-on, to provide an output signal indicative of the occurrence of or margin against regeneration errors. The output signal is available for remote monitoring. The error signal may also be used for adaptive equalization by correlation with signals from the equalizer.
Inventors
- 👤 Frederick Donald Waldhauer
- 👤 Dan Holden Wolaver
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:41
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/20; H04L25/24; H04L25/242; H04L1/00; H04L1/20; H04L25/03; H04L25/03006; H04L25/03012; H04L25/03019
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
113 words
In a regenerative repeater for regenerating digital signals passed as pulse signals through a transmission medium, said repeater including an equalizer and connected in tandem with said equalizer a regenerator having means for admitting an input pulse signal from said equalizer and means for producing a regenerated output pulse signal, and means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output pulse signal, means for delaying said regenerator input pulse signal, means for comparing said delayed regenerator iNput signal with said model pulse signal, and means responsive to said comparison for deriving an error signal containing said information.
Claim 2
Dependent Claim
113 words
In a regenerative repeater for regenerating digital signals passed as pulse signals through a transmission medium, said repeater including an equalizer and connected in tandem with said equalizer a regenerator having means for admitting an input pulse signal from said equalizer and means for producing a regenerated output pulse signal, and means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output pulse signal, means for delaying said regenerator input pulse signal, means for comparing said delayed regenerator iNput signal with said model pulse signal, and means responsive to said comparison for deriving an error signal containing said information.
Claim 3
Dependent Claim
156 words
In a regenerative repeater for regenerating digital pulse signals passed through a transmission medium, said repeater including in tandem an equalizer receiving said signals and a regenerator having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said regenerator output circuit for simulating the pulse shaping of passing said digital signals through an ideal medium and an ideal equalizer, means for delaying said regenerator input signal by the signal delay of said regenerator, means comparing said model pulse signal with said delayed regenerator input signal for providing an error signal containing said information, and means responsive to said comparing means for utilizing said error signal.
Claim 4
Dependent Claim
156 words
In a regenerative repeater for regenerating digital pulse signals passed through a transmission medium, said repeater including in tandem an equalizer receiving said signals and a regenerator having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said regenerator output circuit for simulating the pulse shaping of passing said digital signals through an ideal medium and an ideal equalizer, means for delaying said regenerator input signal by the signal delay of said regenerator, means comparing said model pulse signal with said delayed regenerator input signal for providing an error signal containing said information, and means responsive to said comparing means for utilizing said error signal.
Claim 5
Dependent Claim
164 words
Apparatus for regeneration of digital pulse signals passed through a transmission medium, comprising a repeater including an equalizer and a regenerator having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said regenerator output circuit for simulating the pulse shaping of passing said digital signals through an ideal transmission medium and an ideal equalizer, means for delaying said regenerator input signal by the signal delay of said regenerator, and means comparing said model pulse signal with said delayed regenerator input signal to produce an error signal, and means responsive to said comparing means for utilizing said error signal comprising means for peak-detecting said error signal to provide a direct indication of said margin.
Claim 6
Dependent Claim
164 words
Apparatus for regeneration of digital pulse signals passed through a transmission medium, comprising a repeater including an equalizer and a regenerator having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said regenerator output circuit for simulating the pulse shaping of passing said digital signals through an ideal transmission medium and an ideal equalizer, means for delaying said regenerator input signal by the signal delay of said regenerator, and means comparing said model pulse signal with said delayed regenerator input signal to produce an error signal, and means responsive to said comparing means for utilizing said error signal comprising means for peak-detecting said error signal to provide a direct indication of said margin.
Claim 7
Dependent Claim
155 words
Apparatus for regeneration of digital pulse signals passed through a transmission medium, comprising a repeater including an equalizer and a regenerator having having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said regenerator output circuit for simulating the pulse shaping of passing said digital signals through an ideal transmission medium and an ideal equalizer, means for delaying said regenerator input signal by the signal delay of said regenerator, means comparing said model pulse signal with said delayed regenerator input signal to produce an error signal, and means responsive to said error signal for adjusting said equalizer to increase said margin of said repeater.
Claim 8
Dependent Claim
155 words
Apparatus for regeneration of digital pulse signals passed through a transmission medium, comprising a repeater including an equalizer and a regenerator having having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said regenerator output circuit for simulating the pulse shaping of passing said digital signals through an ideal transmission medium and an ideal equalizer, means for delaying said regenerator input signal by the signal delay of said regenerator, means comparing said model pulse signal with said delayed regenerator input signal to produce an error signal, and means responsive to said error signal for adjusting said equalizer to increase said margin of said repeater.
Claim 9
Dependent Claim
157 words
In a regenerative repeater for regenerating digital pulse signals passed through a transmission medium, said repeater including an equalizer and a regenerator having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said regenerator output circuit for simulating the pulse shaping of passing said digital signals through an ideal medium and an ideal equalizer, means for delaying said regenerator input signal by the signal delay of said regenerator, means for comparing said model pulse signal with said delayed regenerator input signal, and means including correlation means responding to said comparing means and to said equalizer for adjusting said equalizer to increase said margin of said repeater.
Claim 10
Dependent Claim
157 words
In a regenerative repeater for regenerating digital pulse signals passed through a transmission medium, said repeater including an equalizer and a regenerator having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said regenerator output circuit for simulating the pulse shaping of passing said digital signals through an ideal medium and an ideal equalizer, means for delaying said regenerator input signal by the signal delay of said regenerator, means for comparing said model pulse signal with said delayed regenerator input signal, and means including correlation means responding to said comparing means and to said equalizer for adjusting said equalizer to increase said margin of said repeater.
Claim 11
Dependent Claim
183 words
Apparatus for regeneration of digital pulse signals passed through a transmission medium, comprising a repeater including an equalizer including filtering means for a portion of the transmitted spectrum and a regenerator having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said output terminals for simulating the pulse shaping of passing said digital signals through an ideal transmission medium and an ideal equalizer, means for delaying signals proportional to the signals from said equalizer by the signal delay of said regenerator, means comparing said model pulse signal with said delayed regenerator input signal to produce an error signal, and means including at least one correlator responsive to the error signal and to a signal from the filtering means in the equalizer for adjusting said equalizer to increase said margin of said repeater.
Claim 12
Dependent Claim
183 words
Apparatus for regeneration of digital pulse signals passed through a transmission medium, comprising a repeater including an equalizer including filtering means for a portion of the transmitted spectrum and a regenerator having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said output terminals for simulating the pulse shaping of passing said digital signals through an ideal transmission medium and an ideal equalizer, means for delaying signals proportional to the signals from said equalizer by the signal delay of said regenerator, means comparing said model pulse signal with said delayed regenerator input signal to produce an error signal, and means including at least one correlator responsive to the error signal and to a signal from the filtering means in the equalizer for adjusting said equalizer to increase said margin of said repeater.
Claim 13
Dependent Claim
55 words
Apparatus according to claim 6 in which said correlator includes means for multiplying the error signal by a signal transmitted by the filtering means in the equalizer, said filtering means comprising band-pass filter means connected in said equalizer for producing said transmitted signal, said correlator including low-pass filtering means in tandem with said multiplying means.
Claim 14
Dependent Claim
155 words
Apparatus for regeneration of digital pulse signals passed through a transmission medium, comprising a repeater including an equalizer and a regenerator having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said output terminals for simulating the pulse shaping of passing said digital signals through an ideal transmission medium and an ideal equalizer, means for delaying said regenerator input signal by the signal delay of said regenerator, means comparing said model pulse signal with said delayed regenerator input signal to produce a difference signal, and means for peak-rectifying said difference signal to yield an analog signal as an indication of margin against regeneration errors.
Claim 15
Dependent Claim
155 words
Apparatus for regeneration of digital pulse signals passed through a transmission medium, comprising a repeater including an equalizer and a regenerator having an inherent signal delay and having an input circuit connected to said equalizer and an output circuit from which the regenerator output pulse signal issues after said signal delay, means for deriving information about the margin against regenerative error in said repeater comprising means for generating a model pulse signal from said regenerator output signal comprising filtering means connected to said output terminals for simulating the pulse shaping of passing said digital signals through an ideal transmission medium and an ideal equalizer, means for delaying said regenerator input signal by the signal delay of said regenerator, means comparing said model pulse signal with said delayed regenerator input signal to produce a difference signal, and means for peak-rectifying said difference signal to yield an analog signal as an indication of margin against regeneration errors.
Claim 16
Dependent Claim
136 words
Apparatus for regeneration of digital signals in a first digital transmission line, comprising a threshold-detecting and amplifying means for regenerating a stream of pulses in response to pulses received from said line, means for deriving information about the margin against regeneration errors in said repeater comprising means coupled to the regenerating means for deriving a model stream of pulses, said deriving means including means for simulating an ideal equalized section of digital transmission line, means responsive to the pulses received from said first line for producing a delayed stream of pulses replicating the received pulses, means for comparing the model stream and delayed stream to produce an analog difference signal, and means coupled to the comparing means for peak-detecting the difference signal to yield an analog signal as an indication of the margin against regeneration errors.
Claim 17
Dependent Claim
136 words
Apparatus for regeneration of digital signals in a first digital transmission line, comprising a threshold-detecting and amplifying means for regenerating a stream of pulses in response to pulses received from said line, means for deriving information about the margin against regeneration errors in said repeater comprising means coupled to the regenerating means for deriving a model stream of pulses, said deriving means including means for simulating an ideal equalized section of digital transmission line, means responsive to the pulses received from said first line for producing a delayed stream of pulses replicating the received pulses, means for comparing the model stream and delayed stream to produce an analog difference signal, and means coupled to the comparing means for peak-detecting the difference signal to yield an analog signal as an indication of the margin against regeneration errors.
Claim 18
Dependent Claim
40 words
Apparatus according to claim 9 in which the peak-detecting means includes a detecting dioDe and means for clamping the potential across the detecting diode in its off condition to substantially 0 volts regardless of the value of the peak-detected signal.
Claim 19
Dependent Claim
37 words
Apparatus according to claim 9 including means for disabling the comparing means partially, so that the peak-detecting means detects variations in the peak value of the pulse stream from the simulated equalized section of digital transmission line.
Claim 20
Dependent Claim
51 words
Apparatus according to claim 11 in which the disabling means includes a detecting diode and a switch connected between the delayed pulse stream producing means and the comparing means, and means for driving said switch periodically, said driving means including means connected to the peak-detecting means for resetting the peak-detecting means.
Claim 21
Dependent Claim
24 words
Apparatus according to claim 12 including means for modulating the output of the peak-detecting means for transmission to points remote from the regenerating means.
Claim 22
Dependent Claim
72 words
Apparatus according to claim 9 in which the means for simulating an ideal equalized section of digital transmission line includes means for splitting the pulse energy received from the regenerating means into two paths, the first path including a resistive bridged-T and the second path including a plurality of bridged-T sections having respective different transmission delays, and means for recombining pulses from the two paths at the output of said simulating means.
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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) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |