SE8205840L - echo canceller - Google Patents

echo canceller

Info

Publication number
SE8205840L
SE8205840L SE8205840A SE8205840A SE8205840L SE 8205840 L SE8205840 L SE 8205840L SE 8205840 A SE8205840 A SE 8205840A SE 8205840 A SE8205840 A SE 8205840A SE 8205840 L SE8205840 L SE 8205840L
Authority
SE
Sweden
Prior art keywords
signal
echo
end speech
echo canceller
combiner
Prior art date
Application number
SE8205840A
Other languages
Unknown language ( )
Swedish (sv)
Other versions
SE8205840D0 (en
Inventor
R P Coulter
Original Assignee
Western Electric Co
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 Western Electric Co filed Critical Western Electric Co
Publication of SE8205840D0 publication Critical patent/SE8205840D0/en
Publication of SE8205840L publication Critical patent/SE8205840L/en

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
    • H04B3/237—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 two adaptive filters, e.g. for near end and for end echo cancelling
    • 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
    • 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)
  • Noise Elimination (AREA)

Abstract

An echo canceller with improved near-end speech detection consists of a transversal filter (12) which synthesizes from an input signal (x(k)) on a receive signal path (12) an estimate of an echo replica signal (@(k)). A combiner (20) subtracts the echo replica estimate signal from the actual return echo signal (y(k)) on transmit signal path (14) to generate a first echo cancelled signal e(k). The improved near-end speech detector (24) comprises a combiner (28) and a transversal filter (26) which operate to generate a second echo cancelled signal (ed(k)) which is employed by a near-end speech detector (22) which compares the echo cancelled signal to past and present values of the input signal x(k) to ascertain the presence of near-end speech and inhibit the echo canceller. <IMAGE>
SE8205840A 1981-10-23 1982-10-14 echo canceller SE8205840L (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US31449781A 1981-10-23 1981-10-23

Publications (2)

Publication Number Publication Date
SE8205840D0 SE8205840D0 (en) 1982-10-14
SE8205840L true SE8205840L (en) 1983-04-24

Family

ID=23220193

Family Applications (1)

Application Number Title Priority Date Filing Date
SE8205840A SE8205840L (en) 1981-10-23 1982-10-14 echo canceller

Country Status (8)

Country Link
JP (1) JPS58125920A (en)
KR (1) KR840002180A (en)
AU (1) AU8965482A (en)
DE (1) DE3238549A1 (en)
FR (1) FR2515452A1 (en)
GB (1) GB2109209A (en)
NL (1) NL8204099A (en)
SE (1) SE8205840L (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6076825A (en) * 1983-10-03 1985-05-01 Nec Corp Adaptive echo canceller
JPH0624327B2 (en) * 1985-05-24 1994-03-30 日本電気株式会社 Terminal device
JPS6235723A (en) * 1985-08-08 1987-02-16 Matsushita Electric Ind Co Ltd Echo canceling device
EP0307765A1 (en) * 1987-09-18 1989-03-22 Siemens Aktiengesellschaft Arrangement for detecting periodic signals for a speech echo canceller
US5471527A (en) 1993-12-02 1995-11-28 Dsc Communications Corporation Voice enhancement system and method
US5978763A (en) * 1995-02-15 1999-11-02 British Telecommunications Public Limited Company Voice activity detection using echo return loss to adapt the detection threshold
GB2308283A (en) * 1995-12-16 1997-06-18 Ibm System and method for echo cancellation

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1816153B2 (en) * 1968-12-20 1971-04-15 CIRCUIT ARRANGEMENT FOR ECHO SUPPRESSION IN A TALK CIRCUIT ON A FOUR WIRE TRANSMISSION SYSTEM IN THE CASE OF A TRANSITION TO A TWO WIRE TRANSMISSION PATH
US3992594A (en) * 1975-10-10 1976-11-16 Bell Telephone Laboratories, Incorporated Echo suppressor break-in circuitry
JPS56153850A (en) * 1980-04-28 1981-11-28 Kokusai Denshin Denwa Co Ltd <Kdd> Echo control system

Also Published As

Publication number Publication date
NL8204099A (en) 1983-05-16
AU8965482A (en) 1983-04-28
JPS58125920A (en) 1983-07-27
GB2109209A (en) 1983-05-25
FR2515452A1 (en) 1983-04-29
KR840002180A (en) 1984-06-11
DE3238549A1 (en) 1983-05-19
SE8205840D0 (en) 1982-10-14

Similar Documents

Publication Publication Date Title
KR960702965A (en) Echo cancellation device and echo path estimation method
MY118091A (en) Double talk and echo path change detection in a telephony system
SE9504520L (en) Method and apparatus for echo extinguishing by estimating residual signal power
ATE38753T1 (en) ECHO CANCELLATION SYSTEMS.
CA2051147A1 (en) Echo canceller using impulse response estimating method
SE7709560L (en) ECO-ELIMINATOR
IT1250130B (en) RECEIVING APPARATUS.
MY124227A (en) Noise suppressing apparatus capable of preventing deterioration in high frequency signal characteristic after noise suppression and in balanced signal transmitting system
JPS6442929A (en) All double data transmission tranceiver
EP0708536B8 (en) Echo canceler and its learning method
SE9301666L (en) Method and echo extinguisher for echo extinguishing with a number of cascade-coupled adaptive filters
EP0792029A3 (en) Echo canceller E-side speech detector
SE8205840D0 (en) echo canceller
TR199902332T2 (en) Method and equipment for controlling the echo occurring at both ends of a connection
DE59108356D1 (en) Method for checking transmission properties of a subscriber line circuit
SE8205839L (en) echo canceller
DK0635178T3 (en) Method of avoiding self-oscillation associated with echo suppression
ATE214850T1 (en) DEVICE FOR REDUCING THE RISK OF UNDESIRABLE PARAMETER DEVIATIONS OF AN ADAPTIVE FILTER USED FOR ECHO CANCELLATION
NO913936D0 (en) MEASURING DETECTOR ELIMINATING INSIDE THE RANGE OF SENSITIVITY
FI925294A0 (en) FRAMEWORK FOR RETURN ATTACHED TO RESTEKO-BEGRAENSARE
NO883355L (en) Echo cancellation.
JPS648755A (en) Conference communication equipment

Legal Events

Date Code Title Description
NAV Patent application has lapsed

Ref document number: 8205840-5

Format of ref document f/p: F