JPS61135239A - Echo canceller - Google Patents

Echo canceller

Info

Publication number
JPS61135239A
JPS61135239A JP25802784A JP25802784A JPS61135239A JP S61135239 A JPS61135239 A JP S61135239A JP 25802784 A JP25802784 A JP 25802784A JP 25802784 A JP25802784 A JP 25802784A JP S61135239 A JPS61135239 A JP S61135239A
Authority
JP
Grant status
Application
Patent type
Prior art keywords
signal
narrow
echo
band
filter
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
JP25802784A
Inventor
Kiyotaka Nagai
Ryoji Suzuki
Akiyoshi Yamada
Original Assignee
Matsushita Electric Ind 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

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B3/00Line transmission systems
    • H04B3/02Details
    • H04B3/20Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other
    • H04B3/23Reducing 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
    • H04B3/238Reducing 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

Abstract

PURPOSE:To secure the stable working of an echo canceller at all times despite a long-time input of a narrow-band signal, by detecting the narrow-band properties of a received input signal and inhibiting the correction of coefficient of an adaptive filter. CONSTITUTION:An adaptive filter 5 stores the estimated impulse response of an echo route 9 as the coefficient of the filter 5 and filters the input signal received through a terminal 1 to produce an artificial echo signal and to supply this echo signal to a subtractor 6. The subtractor 6 subtracts the echo signal from the signal supplied through an input terminal 3 at the transmission side through a route 9 with cancellation of the echo component to deliver the subtracted signal through an output terminal 4 at the transmission side. A narrow-band signal detector 7 measures the narrow-band properties of the input signal at the reception side and inhibits the correction of the coefficient of the filter 5 when a narrow-band signal is decided. Thus an echo canceller has the stable working with no accumulation of arithmetic errors of the tap coefficient of the filter 5 despite the long-time reception of the narrow-band signal.
JP25802784A 1984-12-06 1984-12-06 Echo canceller Pending JPS61135239A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP25802784A JPS61135239A (en) 1984-12-06 1984-12-06 Echo canceller

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP25802784A JPS61135239A (en) 1984-12-06 1984-12-06 Echo canceller

Publications (1)

Publication Number Publication Date
JPS61135239A true true JPS61135239A (en) 1986-06-23

Family

ID=17314511

Family Applications (1)

Application Number Title Priority Date Filing Date
JP25802784A Pending JPS61135239A (en) 1984-12-06 1984-12-06 Echo canceller

Country Status (1)

Country Link
JP (1) JPS61135239A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0307765A1 (en) * 1987-09-18 1989-03-22 Siemens Aktiengesellschaft Arrangement for detecting periodic signals for a speech echo canceller
US6895086B2 (en) 2001-11-13 2005-05-17 Inmate Telephone, Inc. 3-Way call detection system and method
JP2005269546A (en) * 2004-03-22 2005-09-29 Pioneer Electronic Corp Device, method and program for echo cancellation
JP2005531200A (en) * 2002-06-24 2005-10-13 フリースケール セミコンダクター インコーポレイテッド Communication system and method therefor
US7248685B2 (en) 2003-08-05 2007-07-24 Inmate Telephone, Inc. Three-way call detection using steganography
US8942356B2 (en) 2007-02-15 2015-01-27 Dsi-Iti, Llc System and method for three-way call detection
US9225838B2 (en) 2009-02-12 2015-12-29 Value-Added Communications, Inc. System and method for detecting three-way call circumvention attempts
US9923936B2 (en) 2016-04-07 2018-03-20 Global Tel*Link Corporation System and method for third party monitoring of voice and video calls
US9930088B1 (en) 2017-06-22 2018-03-27 Global Tel*Link Corporation Utilizing VoIP codec negotiation during a controlled environment call
US10027797B1 (en) 2017-05-10 2018-07-17 Global Tel*Link Corporation Alarm control for inmate call monitoring

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0307765A1 (en) * 1987-09-18 1989-03-22 Siemens Aktiengesellschaft Arrangement for detecting periodic signals for a speech echo canceller
US7664243B2 (en) 2001-11-13 2010-02-16 Inmate Telephone, Inc. 3-way call detection system and method
US6895086B2 (en) 2001-11-13 2005-05-17 Inmate Telephone, Inc. 3-Way call detection system and method
US7123704B2 (en) 2001-11-13 2006-10-17 Inmate Telephone, Inc. 3-Way call detection system
JP2005531200A (en) * 2002-06-24 2005-10-13 フリースケール セミコンダクター インコーポレイテッド Communication system and method therefor
US7248685B2 (en) 2003-08-05 2007-07-24 Inmate Telephone, Inc. Three-way call detection using steganography
US7826604B2 (en) 2003-08-05 2010-11-02 Dsi-Iti, Llc Three-way call detection using steganography
JP2005269546A (en) * 2004-03-22 2005-09-29 Pioneer Electronic Corp Device, method and program for echo cancellation
US9621732B2 (en) 2007-02-15 2017-04-11 Dsi-Iti, Llc System and method for three-way call detection
US9930173B2 (en) 2007-02-15 2018-03-27 Dsi-Iti, Llc System and method for three-way call detection
US8942356B2 (en) 2007-02-15 2015-01-27 Dsi-Iti, Llc System and method for three-way call detection
US9225838B2 (en) 2009-02-12 2015-12-29 Value-Added Communications, Inc. System and method for detecting three-way call circumvention attempts
US10057398B2 (en) 2009-02-12 2018-08-21 Value-Added Communications, Inc. System and method for detecting three-way call circumvention attempts
US9923936B2 (en) 2016-04-07 2018-03-20 Global Tel*Link Corporation System and method for third party monitoring of voice and video calls
US10027797B1 (en) 2017-05-10 2018-07-17 Global Tel*Link Corporation Alarm control for inmate call monitoring
US9930088B1 (en) 2017-06-22 2018-03-27 Global Tel*Link Corporation Utilizing VoIP codec negotiation during a controlled environment call

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