JPS5789337A - Echo erasing device - Google Patents

Echo erasing device

Info

Publication number
JPS5789337A
JPS5789337A JP16563180A JP16563180A JPS5789337A JP S5789337 A JPS5789337 A JP S5789337A JP 16563180 A JP16563180 A JP 16563180A JP 16563180 A JP16563180 A JP 16563180A JP S5789337 A JPS5789337 A JP S5789337A
Authority
JP
Japan
Prior art keywords
level
echo
signal
output
measuring circuit
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
JP16563180A
Other languages
Japanese (ja)
Other versions
JPH0131731B2 (en
Inventor
Hidenori Ito
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 JP16563180A priority Critical patent/JPS5789337A/en
Publication of JPS5789337A publication Critical patent/JPS5789337A/en
Publication of JPH0131731B2 publication Critical patent/JPH0131731B2/ja
Granted legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/20—Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other
    • H04B3/23—Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other using a replica of transmitted signal in the time domain, e.g. echo cancellers

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

PURPOSE:To prevent the lowering of the quantity of echo erase, by detecting rapidly the overlap speech state even for a low overlap signal level and a low echo signal level by detecting the level of the transmission-side signal in the output level. CONSTITUTION:The receiving-side signal has the level measured by a receiving- side signal level measuring circuit 8, and the erase residual echo in the transmission output side of a subtracting circuit 6 of an echo erasing part 5 has the level measured by a erase residual signal level measuring circuit 9 as a transmission-side signal. On the basis of outputs of both level measuring circuits 8 and 9, the sum of echo loss and cancellation is obtained by an attenuation quantity measuring circuit 10. The attenuation quantity level from the attenuation quantity measuring circuit 10 and the receiving-side output signal level are inputted to an operation circuit 11 for an erase residual echo level estimated value to obtain the estimated value of the erase residual echo level. This estimated value is compared with the output of the erase residual signal level measuring circuit 9 by a comparing circit 12, and an approximate echo signal synthesizing circuit 7 is controlled by the comparison output.
JP16563180A 1980-11-25 1980-11-25 Echo erasing device Granted JPS5789337A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16563180A JPS5789337A (en) 1980-11-25 1980-11-25 Echo erasing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16563180A JPS5789337A (en) 1980-11-25 1980-11-25 Echo erasing device

Publications (2)

Publication Number Publication Date
JPS5789337A true JPS5789337A (en) 1982-06-03
JPH0131731B2 JPH0131731B2 (en) 1989-06-27

Family

ID=15816027

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16563180A Granted JPS5789337A (en) 1980-11-25 1980-11-25 Echo erasing device

Country Status (1)

Country Link
JP (1) JPS5789337A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5949027A (en) * 1982-09-14 1984-03-21 Fujitsu Ltd Echo canceller controlling system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5949027A (en) * 1982-09-14 1984-03-21 Fujitsu Ltd Echo canceller controlling system

Also Published As

Publication number Publication date
JPH0131731B2 (en) 1989-06-27

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