US3586781A
Expired / Lapsed
US
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Telecommunication apparatus
Assignee: TECHNOLOGY UK
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Filing: 1970-05-19
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Granted: 1971-06-22
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Expires: 1990-05-19
Abstract
Abstract In telecommunications apparatus for transmitting a speech signal and at least one digital data signal in different frequency ranges over a common channel, the amplitude of the data signals is made to follow the mean amplitude of the speech signal. An amplitude limiter circuit may be provided in the speech signal path; the amplitude-limiting action of this circuit is preferably controlled by a signal derived from a sample or simulation of the intermodulation, distortion and noise-producing effects of the common channel. A controllable amplitude-limiter circuit is described.
Inventors
- 👤 Elwyn T Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 00:54
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/06; H04M11/062
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
200 words
Telecommunications transmitting apparatus for transmitting a speech signal and at least one digital data signal in different frequency ranges over a common telecommunications channel, said apparatus comprising: a speech signal path, a data signal path, transmitting means responsive to signals from said speech signal path and to signals from said data signal path for transmitting said signals over said common telecommunications channel, an electrically controllable amplitude limiter circuit connected in said speech signal path, amplitude adjusting means series connected in one of said signal paths, first control means connected both to said speech signal path and to said amplitude adjusting means for controlling the amplitude adjusting means to cause data signal amplitude applied to said transmitting means to increase when mean speech signal amplitude concurrently applied to said transmitting means increases, and second control means connected to said transmitting means and to said amplitude limiter circuit for deriving a signal representative of interference and noise effects liable to effect reproduction of said data signals due to transmission of the speech signal in a common telecommunications channel and for controlling said amplitude limiter circuit to intensify the amplitude limiting action thereof, whenever said interference and noise effects exceed a predetermined amplitude.
Claim 2
Dependent Claim
200 words
Telecommunications transmitting apparatus for transmitting a speech signal and at least one digital data signal in different frequency ranges over a common telecommunications channel, said apparatus comprising: a speech signal path, a data signal path, transmitting means responsive to signals from said speech signal path and to signals from said data signal path for transmitting said signals over said common telecommunications channel, an electrically controllable amplitude limiter circuit connected in said speech signal path, amplitude adjusting means series connected in one of said signal paths, first control means connected both to said speech signal path and to said amplitude adjusting means for controlling the amplitude adjusting means to cause data signal amplitude applied to said transmitting means to increase when mean speech signal amplitude concurrently applied to said transmitting means increases, and second control means connected to said transmitting means and to said amplitude limiter circuit for deriving a signal representative of interference and noise effects liable to effect reproduction of said data signals due to transmission of the speech signal in a common telecommunications channel and for controlling said amplitude limiter circuit to intensify the amplitude limiting action thereof, whenever said interference and noise effects exceed a predetermined amplitude.
Claim 3
Dependent Claim
123 words
Apparatus as in claim 1 wherein said transmitting means comprises: a band stop filter connected to said speech signal path, a band pass filter connected to said data signal path, a transmitter connected to outputs of said band stop filter and said band pass filter; and where said second control means comprises: a second band stop filter connected to said speech signal path, line simulator means connected to an output of said second band stop filter for simulating probable intermodulation, distortion and noise-producing effects of said common telecommunications channel, a second band-pass filter connected to an output of said line simulator means, and a control circuit connected to an output of said second band pass filter and responsive to signal amplitudes obtained therefrom.
Claim 4
Dependent Claim
31 words
Apparatus as in claim 2 wherein said amplitude limiter circuit comprises: an impedance in series with said speech signal path, and a variable load in parallel with said speech signal path.
Claim 5
Dependent Claim
31 words
Apparatus as in claim 3 wherein said variable load comprises: a rectifier circuit, and a bias voltage source circuit connected thereto for applying a reverse bias voltage to said rectifier circuit.
Claim 6
Dependent Claim
38 words
Apparatus as in claim 4 wherein said control circuit comprises: rectifying means having input connections to an output of said second band pass filter, and said rectifying means also having output connections to said bias voltage source circuit.
Claim 7
Dependent Claim
38 words
Apparatus as in claim 5 wherein said bias voltage source circuit comprises: a potentiometer chain, and at least one transistor connected in parallel with part of said potentiometer chain and connected to an output of said rectifying means.
Claim 8
Dependent Claim
180 words
Telecommunications transmitting apparatus for transmitting a speech signal and at least one digital data signal in different frequency ranges over a common telecommunications channel, said apparatus comprising: a speech signal path, a data signal path, transmitting means having a common input connection responsive to signals from said speech signal path and to signals from said data signal path for transmitting said signals over said common telecommunications channel, amplitude adjusting means, series-connected in said data signal path, and having a control input, for continuously adjusting the amplitude of the signals in the said path in response to variations of a signal applied to said control input, while preserving the waveform of said signals substantially undistorted, and control means connected to said speech signal path and to said control input of said amplitude adjusting means for controlling said amplitude-adjusting means to cause the amplitude of data signals applied to said transmitting means to follow variations in the mean amplitude of speech signals concurrently applied to said transmitting means so that the data signal amplitude will increase whenever the speech-signal mean amplitude increases.
Claim 9
Dependent Claim
180 words
Telecommunications transmitting apparatus for transmitting a speech signal and at least one digital data signal in different frequency ranges over a common telecommunications channel, said apparatus comprising: a speech signal path, a data signal path, transmitting means having a common input connection responsive to signals from said speech signal path and to signals from said data signal path for transmitting said signals over said common telecommunications channel, amplitude adjusting means, series-connected in said data signal path, and having a control input, for continuously adjusting the amplitude of the signals in the said path in response to variations of a signal applied to said control input, while preserving the waveform of said signals substantially undistorted, and control means connected to said speech signal path and to said control input of said amplitude adjusting means for controlling said amplitude-adjusting means to cause the amplitude of data signals applied to said transmitting means to follow variations in the mean amplitude of speech signals concurrently applied to said transmitting means so that the data signal amplitude will increase whenever the speech-signal mean amplitude increases.
Claim 10
Dependent Claim
17 words
Apparatus as in claim 7 wherein an amplitude limiter circuit is provided in said speech signal path.
Claim 11
Dependent Claim
21 words
Apparatus as in claim 7 wherein said transmitting means includes equipment of the class comprising pulse code modulators and delta modulators.
Claim 12
Dependent Claim
184 words
Telecommunications transmitting apparatus for transmitting speech signals and at least one digital date signal in different frequency ranges over a common telecommunications channel, said apparatus comprising: a speech signal path for carrying said speech signals, a data signal path for carrying said data signals, transmitting means for transmitting both said speech and said data signals over said common telecommunications channel, and means for maintaining a substantially constant ratio between the transmitted speech signal amplitudes and the transmitted data signal amplitudes, said means comprising: amplitude adjusting means, series connected in one of said signal paths, and having a control input for continuously adjusting the amplitude of signals in the said one of said signal paths in response to variations of a signal applied to said control input, while preserving the waveform of said signals substantially undistorted, and control means connected both to said transmitting means and to said contRol input of said amplitude adjusting means, for varying signal amplitude in at least one of said signal paths so as to maintain said ratio substantially constant despite natural variations in the amplitude of said speech signals.
Claim 13
Dependent Claim
184 words
Telecommunications transmitting apparatus for transmitting speech signals and at least one digital date signal in different frequency ranges over a common telecommunications channel, said apparatus comprising: a speech signal path for carrying said speech signals, a data signal path for carrying said data signals, transmitting means for transmitting both said speech and said data signals over said common telecommunications channel, and means for maintaining a substantially constant ratio between the transmitted speech signal amplitudes and the transmitted data signal amplitudes, said means comprising: amplitude adjusting means, series connected in one of said signal paths, and having a control input for continuously adjusting the amplitude of signals in the said one of said signal paths in response to variations of a signal applied to said control input, while preserving the waveform of said signals substantially undistorted, and control means connected both to said transmitting means and to said contRol input of said amplitude adjusting means, for varying signal amplitude in at least one of said signal paths so as to maintain said ratio substantially constant despite natural variations in the amplitude of said speech signals.
Claim 14
Dependent Claim
21 words
Apparatus as in claim 10 wherein said amplitude means comprises a variable gain amplifier series connected in said data signal path.
Claim 15
Dependent Claim
35 words
Apparatus as in claim 11 wherein said first control means is connected to said speech signal path for adjusting the gain of said variable gain amplifier in accordance with the amplitude of said speech signal.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |