JPS5742241A - Echo erasion type two-wire bidirectional amplifier - Google Patents
Echo erasion type two-wire bidirectional amplifierInfo
- Publication number
- JPS5742241A JPS5742241A JP11795480A JP11795480A JPS5742241A JP S5742241 A JPS5742241 A JP S5742241A JP 11795480 A JP11795480 A JP 11795480A JP 11795480 A JP11795480 A JP 11795480A JP S5742241 A JPS5742241 A JP S5742241A
- Authority
- JP
- Japan
- Prior art keywords
- echo
- circuit
- amount
- erasion
- gain
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Abstract
PURPOSE:To prevent the deterioration of quality of call due to level contrast, by controlling the gain of a variable gain amplifier connected to the reception input of an echo erasing circuit through the output of a detection circuit estimating the amount of erasion of echo. CONSTITUTION:When a signal comes from two-wire side of a direction E, an echo erasing circuit 12 of a direction W is operated, the amount of echo at W transmission side is erased and the amount of erasion is calculated with an echo erasing amount detection circuit 20 and the gain is increased by the amount of erasion for a variable gain amplifier circuit 5 at the E transmission side. When a call only from the W side is made from this state, an echo erasing circuit 11 at the E side is operated and gain direction control of the circuit 5' at the E side transmission side is made and it is operated as two-wire bidirectional amplifier. Thus, in a line having much loss, the voice with a gain from the original call is delivered to the opposing party and it is not required to obtain a greater loss to the opposing side.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11795480A JPS5742241A (en) | 1980-08-27 | 1980-08-27 | Echo erasion type two-wire bidirectional amplifier |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP11795480A JPS5742241A (en) | 1980-08-27 | 1980-08-27 | Echo erasion type two-wire bidirectional amplifier |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5742241A true JPS5742241A (en) | 1982-03-09 |
JPS6221457B2 JPS6221457B2 (en) | 1987-05-13 |
Family
ID=14724346
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP11795480A Granted JPS5742241A (en) | 1980-08-27 | 1980-08-27 | Echo erasion type two-wire bidirectional amplifier |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5742241A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5742242A (en) * | 1980-08-27 | 1982-03-09 | Nec Corp | Two-wire type bidirectional amplifier system |
EP0174781A2 (en) * | 1984-09-07 | 1986-03-19 | AT&T Corp. | Bidirectional adaptive voice frequency repeater |
EP0176262A2 (en) * | 1984-09-07 | 1986-04-02 | AT&T Corp. | Bidirectional adaptive voice frequency repeater |
US4782525A (en) * | 1985-11-25 | 1988-11-01 | Northern Telecom Limited | Echo cancellation in two-wire transmission path repeaters |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS55117955A (en) * | 1979-03-05 | 1980-09-10 | Fujitsu Ltd | Semiconductor sensor and impurity detection method |
-
1980
- 1980-08-27 JP JP11795480A patent/JPS5742241A/en active Granted
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS55117955A (en) * | 1979-03-05 | 1980-09-10 | Fujitsu Ltd | Semiconductor sensor and impurity detection method |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5742242A (en) * | 1980-08-27 | 1982-03-09 | Nec Corp | Two-wire type bidirectional amplifier system |
JPS6223936B2 (en) * | 1980-08-27 | 1987-05-26 | Nippon Electric Co | |
EP0174781A2 (en) * | 1984-09-07 | 1986-03-19 | AT&T Corp. | Bidirectional adaptive voice frequency repeater |
EP0176262A2 (en) * | 1984-09-07 | 1986-04-02 | AT&T Corp. | Bidirectional adaptive voice frequency repeater |
US4782525A (en) * | 1985-11-25 | 1988-11-01 | Northern Telecom Limited | Echo cancellation in two-wire transmission path repeaters |
Also Published As
Publication number | Publication date |
---|---|
JPS6221457B2 (en) | 1987-05-13 |
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