GB2008903A - Echo suppressors - Google Patents

Echo suppressors

Info

Publication number
GB2008903A
GB2008903A GB7845029A GB7845029A GB2008903A GB 2008903 A GB2008903 A GB 2008903A GB 7845029 A GB7845029 A GB 7845029A GB 7845029 A GB7845029 A GB 7845029A GB 2008903 A GB2008903 A GB 2008903A
Authority
GB
United Kingdom
Prior art keywords
hybrid
transmission
circuit
filter
echo suppressors
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
GB7845029A
Other versions
GB2008903B (en
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.)
General Electric Co PLC
Original Assignee
General Electric Co PLC
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 General Electric Co PLC filed Critical General Electric Co PLC
Priority to GB7845029A priority Critical patent/GB2008903B/en
Publication of GB2008903A publication Critical patent/GB2008903A/en
Application granted granted Critical
Publication of GB2008903B publication Critical patent/GB2008903B/en
Expired 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

A 4-wire loop-extender circuit for a 2-wire telephone line in which each hybrid transformer (or other hybrid circuit) 6, 7 has an adaptive filter 12, 13 connected between its two simplex paths to simulate the impulse response of the hybrid and provide an equal and cancelling signal for any leakage. Double-talk detectors 17, 18 only allow adaptation of the filters when a transmission signal is present, and a noise generator 19 is used to train each filter at the start of each transmission. <IMAGE>
GB7845029A 1977-08-17 1978-11-17 Amplifier arrangements Expired GB2008903B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB7845029A GB2008903B (en) 1977-08-17 1978-11-17 Amplifier arrangements

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB3452977 1977-08-17
GB7845029A GB2008903B (en) 1977-08-17 1978-11-17 Amplifier arrangements

Publications (2)

Publication Number Publication Date
GB2008903A true GB2008903A (en) 1979-06-06
GB2008903B GB2008903B (en) 1982-06-30

Family

ID=26262320

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7845029A Expired GB2008903B (en) 1977-08-17 1978-11-17 Amplifier arrangements

Country Status (1)

Country Link
GB (1) GB2008903B (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3141501A1 (en) * 1980-10-23 1982-06-24 International Standard Electric Corp., 10022 New York, N.Y. CIRCUIT ARRANGEMENT FOR TWO-WIRE VIE3RWAW-IMPLEMENTATION, IN PARTICULAR DIGITAL SUBSCRIBER CONNECTION CIRCUIT WITH MEANS FOR AUTOMATIC IMPEDANCE ADAPTATION TO THE SUBSCRIBER LINE
EP0054609A2 (en) * 1980-12-17 1982-06-30 ANT Nachrichtentechnik GmbH Arrangement for adjusting the echo cancellation coefficients at combined adaptive echo cancellation and equalization
DE3141503A1 (en) * 1980-10-23 1982-07-08 International Standard Electric Corp., 10022 New York, N.Y. CIRCUIT ARRANGEMENT FOR TWO-WIRE-FOUR-WIRE CONVERSION, IN PARTICULAR DIGITAL SUBSCRIBER CONNECTION
DE3141502A1 (en) * 1980-10-23 1982-07-29 International Standard Electric Corp., 10022 New York, N.Y. INTERFACE DEVICE FOR CONNECTING TELEPHONE SUBSCRIBER LINES TO A DIGITAL SWITCH
FR2501436A1 (en) * 1981-03-05 1982-09-10 Western Electric Co
GB2162679A (en) * 1984-06-25 1986-02-05 Duracell Int Auxiliary portable power supply
US4584441A (en) * 1984-09-07 1986-04-22 At&T Bell Laboratories Bidirectional adaptive voice frequency repeater
US4593161A (en) * 1983-06-30 1986-06-03 International Business Machines Corp. Method of initializing a filter in an echo canceller and communication system using said method
US4621173A (en) * 1982-06-14 1986-11-04 Telecommunications Radioelectriques et Telephoniques T.R.I Method of reducing the convergence time of an echo canceller and apparatus for carrying out said method
US4645884A (en) * 1983-01-31 1987-02-24 Telecommunications Radioelectriques Et Telephoniques Method and apparatus for initializing filter coefficients in an echo canceller
US4712235A (en) * 1984-11-19 1987-12-08 International Business Machines Corporation Method and apparatus for improved control and time sharing of an echo canceller
US4845746A (en) * 1987-06-23 1989-07-04 Rockwell International Corporation Echo canceller with relative feedback control

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3141501A1 (en) * 1980-10-23 1982-06-24 International Standard Electric Corp., 10022 New York, N.Y. CIRCUIT ARRANGEMENT FOR TWO-WIRE VIE3RWAW-IMPLEMENTATION, IN PARTICULAR DIGITAL SUBSCRIBER CONNECTION CIRCUIT WITH MEANS FOR AUTOMATIC IMPEDANCE ADAPTATION TO THE SUBSCRIBER LINE
DE3141503A1 (en) * 1980-10-23 1982-07-08 International Standard Electric Corp., 10022 New York, N.Y. CIRCUIT ARRANGEMENT FOR TWO-WIRE-FOUR-WIRE CONVERSION, IN PARTICULAR DIGITAL SUBSCRIBER CONNECTION
DE3141502A1 (en) * 1980-10-23 1982-07-29 International Standard Electric Corp., 10022 New York, N.Y. INTERFACE DEVICE FOR CONNECTING TELEPHONE SUBSCRIBER LINES TO A DIGITAL SWITCH
EP0054609A2 (en) * 1980-12-17 1982-06-30 ANT Nachrichtentechnik GmbH Arrangement for adjusting the echo cancellation coefficients at combined adaptive echo cancellation and equalization
EP0054609A3 (en) * 1980-12-17 1982-09-22 Ant Nachrichtentechnik Gmbh Arrangement for adjusting the echo cancellation coefficients at combined adaptive echo cancellation and equalization
FR2501436A1 (en) * 1981-03-05 1982-09-10 Western Electric Co
US4621173A (en) * 1982-06-14 1986-11-04 Telecommunications Radioelectriques et Telephoniques T.R.I Method of reducing the convergence time of an echo canceller and apparatus for carrying out said method
US4645884A (en) * 1983-01-31 1987-02-24 Telecommunications Radioelectriques Et Telephoniques Method and apparatus for initializing filter coefficients in an echo canceller
US4593161A (en) * 1983-06-30 1986-06-03 International Business Machines Corp. Method of initializing a filter in an echo canceller and communication system using said method
GB2162679A (en) * 1984-06-25 1986-02-05 Duracell Int Auxiliary portable power supply
US4584441A (en) * 1984-09-07 1986-04-22 At&T Bell Laboratories Bidirectional adaptive voice frequency repeater
US4712235A (en) * 1984-11-19 1987-12-08 International Business Machines Corporation Method and apparatus for improved control and time sharing of an echo canceller
US4845746A (en) * 1987-06-23 1989-07-04 Rockwell International Corporation Echo canceller with relative feedback control

Also Published As

Publication number Publication date
GB2008903B (en) 1982-06-30

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee