JPS5742241A - Echo erasion type two-wire bidirectional amplifier - Google Patents

Echo erasion type two-wire bidirectional amplifier

Info

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
Application number
JP11795480A
Other languages
Japanese (ja)
Other versions
JPS6221457B2 (en
Inventor
Yoshiji Furuya
Yuzo Fukushi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP11795480A priority Critical patent/JPS5742241A/en
Publication of JPS5742241A publication Critical patent/JPS5742241A/en
Publication of JPS6221457B2 publication Critical patent/JPS6221457B2/ja
Granted legal-status Critical Current

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.
JP11795480A 1980-08-27 1980-08-27 Echo erasion type two-wire bidirectional amplifier Granted JPS5742241A (en)

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)

* Cited by examiner, † Cited by third party
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)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS55117955A (en) * 1979-03-05 1980-09-10 Fujitsu Ltd Semiconductor sensor and impurity detection method

Patent Citations (1)

* Cited by examiner, † Cited by third party
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)

* Cited by examiner, † Cited by third party
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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