JPS5792928A - Echo cancelling device - Google Patents

Echo cancelling device

Info

Publication number
JPS5792928A
JPS5792928A JP16859380A JP16859380A JPS5792928A JP S5792928 A JPS5792928 A JP S5792928A JP 16859380 A JP16859380 A JP 16859380A JP 16859380 A JP16859380 A JP 16859380A JP S5792928 A JPS5792928 A JP S5792928A
Authority
JP
Japan
Prior art keywords
echo
circuit
signal
training signal
path characteristic
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.)
Pending
Application number
JP16859380A
Other languages
Japanese (ja)
Inventor
Shigenobu Minami
Tadamichi Kawasaki
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.)
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura 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 Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP16859380A priority Critical patent/JPS5792928A/en
Publication of JPS5792928A publication Critical patent/JPS5792928A/en
Pending 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
    • H04B3/238—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 using initial training sequence

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 estimate effectively an echo path characteristic,by transmitting a training signal before the start of service. CONSTITUTION:When an output is issued from one of an originating discriminator 9 to be called, a receiving detector 10, and a call detector 11, a control circuit regulates the timing for supply of a training signal and the timing for estimation of an echo path characteristic and supplies the output of a training signal generator 6 to an echo canceler circuit 7 and a hybrid circuit 3. The echo cancler circuit 7 estimates the echo path characteristic on a basis of the training signal and the echo signal from the hybrid circuit 3. Next, the control circuit closes a switch 1 and switches a changeover switch 5 to the amplifier 2 side. Thus, the echo canceler circuit 7 generates a false echo signal and the false signal is subtracted from the receiving signal from the hybrid circuit 3 at the service time, thereby eliminating the echo.
JP16859380A 1980-11-29 1980-11-29 Echo cancelling device Pending JPS5792928A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16859380A JPS5792928A (en) 1980-11-29 1980-11-29 Echo cancelling device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16859380A JPS5792928A (en) 1980-11-29 1980-11-29 Echo cancelling device

Publications (1)

Publication Number Publication Date
JPS5792928A true JPS5792928A (en) 1982-06-09

Family

ID=15870922

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16859380A Pending JPS5792928A (en) 1980-11-29 1980-11-29 Echo cancelling device

Country Status (1)

Country Link
JP (1) JPS5792928A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS622316A (en) * 1985-06-27 1987-01-08 Nippon Telegr & Teleph Corp <Ntt> Voice information inputting/outputting system
JPH02280422A (en) * 1989-04-20 1990-11-16 Nec Corp Training method for echo canceller for voice conference equipment
WO1992020170A1 (en) * 1991-04-30 1992-11-12 Kabushiki Kaisha Toshiba Voice communication device provided with echo canceler
JPH0514246A (en) * 1991-07-01 1993-01-22 Iwatsu Electric Co Ltd Bidirectional amplifier
JP2002353863A (en) * 2001-05-30 2002-12-06 Toyo Commun Equip Co Ltd Echo canceller

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS622316A (en) * 1985-06-27 1987-01-08 Nippon Telegr & Teleph Corp <Ntt> Voice information inputting/outputting system
JPH02280422A (en) * 1989-04-20 1990-11-16 Nec Corp Training method for echo canceller for voice conference equipment
WO1992020170A1 (en) * 1991-04-30 1992-11-12 Kabushiki Kaisha Toshiba Voice communication device provided with echo canceler
US5400399A (en) * 1991-04-30 1995-03-21 Kabushiki Kaisha Toshiba Speech communication apparatus equipped with echo canceller
JPH0514246A (en) * 1991-07-01 1993-01-22 Iwatsu Electric Co Ltd Bidirectional amplifier
JP2002353863A (en) * 2001-05-30 2002-12-06 Toyo Commun Equip Co Ltd Echo canceller

Similar Documents

Publication Publication Date Title
CA2167940A1 (en) Method and apparatus for echo cancelling with double-talk immunity
GB1205938A (en) Improvements in or relating to echo suppressors
JPS573101A (en) Multiple control device
JPS5792928A (en) Echo cancelling device
JPS5397714A (en) Signal holding circuit
JPS57152242A (en) Mobile communication control system
JPS5733844A (en) Echo cancelling device
ES444971A1 (en) Offset keying technique for segregated phase comparison relaying
JPS5733843A (en) Echo cancelling device
JPS648755A (en) Conference communication equipment
JPS5685963A (en) Called line indicating circuit of telephone set
GB891959A (en) Improvements in or relating to time assignment speech interpolation systems
JPS53117922A (en) Absence reception voice answer skip system
JPS5390707A (en) Detecting system for circuit fault
JPS5451702A (en) Automatic power supply cut-off circuit
JPS5461808A (en) Audio response unit
JPS54130818A (en) Adaptive echo suppressor
JPS57136857A (en) Audible signal transmission system
JPS53136414A (en) Sending system for subscriber&#39;s line signal
JPS53105923A (en) Automatic test system for ringer
JPS5355905A (en) Automatic dialing system
JPS5535585A (en) Multiple sound signal reception device
JPS5337304A (en) Telephone system
JPS5787629A (en) Single radio device
GB1418085A (en) Circuit arrangement for generating prefix signals in telecommuni cation and particularly telephone systems