Patent US3754105A successfully refreshed from Google Patents.
US3754105A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for echo suppression in a voice circuit on a four-wire transmission system upon transfer to a two-wire transmission line
Assignee: Individual
•
Filing: 1972-06-07
•
Granted: 1973-08-21
•
Expires: 1992-06-07
Abstract
Abstract An echo suppression arrangement for a four-wire to two-wire transfer in a communication system employs a first echo suppressor which is normally inactive and which is rendered active in response to a first comparator of the first echo suppressor and a second comparator of an echo canceller when echo simulation of the canceller is inadequate to compensate for the instant echo.
Inventors
- 👤 W Poschenrieder
- 👤 H Bendel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:28
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
192 words
An arrangement for echo suppression in a voice circuit on a four-wire transmission system upon transfer to a two-wire transmission line switched into the transmission directions of the four-wire transmission line to be looked upon as a sending line and a receiving line with respect to the transfer wherein a first echo suppressor is provided with switching means switched into the sending line controlled by a first comparator and a second echo suppressor provided with an echo simulator fed by the signal of the receiving line, said echo simulator feeding a subtraction device switched into the sending line and being controlled by the output signal of the subtraction device via a second comparator circuit, the improvement therein residing in that said first echo suppressor is connected after said second echo suppressor relative to the sending line and that said first echo sUppressor is normally interconnected to both voice lines, and said second echo suppressor comprises an error signal control circuit connected to control the operation of said first echo suppressor such that the first echo suppressor is activated only when there is inadequate compensation of the echo in the second echo suppressor.
Claim 2
Dependent Claim
192 words
An arrangement for echo suppression in a voice circuit on a four-wire transmission system upon transfer to a two-wire transmission line switched into the transmission directions of the four-wire transmission line to be looked upon as a sending line and a receiving line with respect to the transfer wherein a first echo suppressor is provided with switching means switched into the sending line controlled by a first comparator and a second echo suppressor provided with an echo simulator fed by the signal of the receiving line, said echo simulator feeding a subtraction device switched into the sending line and being controlled by the output signal of the subtraction device via a second comparator circuit, the improvement therein residing in that said first echo suppressor is connected after said second echo suppressor relative to the sending line and that said first echo sUppressor is normally interconnected to both voice lines, and said second echo suppressor comprises an error signal control circuit connected to control the operation of said first echo suppressor such that the first echo suppressor is activated only when there is inadequate compensation of the echo in the second echo suppressor.
Claim 3
Dependent Claim
20 words
An arrangement according to claim 1, characterized in that the first and the second echo suppressors form one constructional unit.
Claim 4
Dependent Claim
53 words
An arrangement according to claim 1, characterized in that the first echo suppressor comprises a four-terminal attenuation network to be switched into the receiving line and said first comparator is connected to control said four-terminal attenuation network in response to the operation of said error signal control circuit of the second echo suppressor.
Claim 5
Dependent Claim
43 words
An arrangement according to claim 3, characterized in that said four-terminal attenuation network compresses the sound volume range of the voice signal of the receiving line in response to the control signals of said first comparator and of said error signal control circuit.
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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |