CA2211994A1 - Apparatus and method for canceling acoustic echoes including non-linear distortions in loudspeaker telephones - Google Patents

Apparatus and method for canceling acoustic echoes including non-linear distortions in loudspeaker telephones

Info

Publication number
CA2211994A1
CA2211994A1 CA002211994A CA2211994A CA2211994A1 CA 2211994 A1 CA2211994 A1 CA 2211994A1 CA 002211994 A CA002211994 A CA 002211994A CA 2211994 A CA2211994 A CA 2211994A CA 2211994 A1 CA2211994 A1 CA 2211994A1
Authority
CA
Canada
Prior art keywords
echo
loudspeaker
sound pressure
signal
estimate
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
CA002211994A
Other languages
French (fr)
Other versions
CA2211994C (en
Inventor
Paul Wilkinson Dent
Torbjorn W. Solve
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.)
Ericsson Inc
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of CA2211994A1 publication Critical patent/CA2211994A1/en
Application granted granted Critical
Publication of CA2211994C publication Critical patent/CA2211994C/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/08—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
    • H04M9/082—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic using echo cancellers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/08—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Telephone Function (AREA)
  • Circuit For Audible Band Transducer (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
  • Soundproofing, Sound Blocking, And Sound Damping (AREA)

Abstract

An echo canceling loudspeaker telephone includes a loudspeaker which produces a sound pressure wave in response to an input signal which is applied to an audio input. thereof. This sound pressure wave includes a desired linear component which is a linear function of the input signal, and an undesired non-linear component which is a non-linear function of the input signal, and the sound pressure wave is transmitted along an acoustic path. A microphone is positioned in the acoustic path and converts the sound pressure wave into an output signal. An echo filter is responsive to the input signal and generates an estimated echo signal. This echo filter includes a loudspeaker model which generates an estimate of the sound pressure: wave including an estimate of the linear component and an estimate of the non-linear component.
This echo filter also includes an acoustic path model which generates an estimate of the acoustic path from the loudspeaker to the microphone. In addition, a subtractor subtracts the estimated echo signal from the output signal thereby reducing an echo portion of said sound signal.
CA002211994A 1995-02-24 1996-02-20 Apparatus and method for canceling acoustic echoes including non-linear distortions in loudspeaker telephones Expired - Fee Related CA2211994C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US08/393,711 1995-02-24
US08/393,711 US5680450A (en) 1995-02-24 1995-02-24 Apparatus and method for canceling acoustic echoes including non-linear distortions in loudspeaker telephones
PCT/US1996/002073 WO1996026592A1 (en) 1995-02-24 1996-02-20 Apparatus and method for canceling acoustic echoes including non-linear distortions in loudspeaker telephones

Publications (2)

Publication Number Publication Date
CA2211994A1 true CA2211994A1 (en) 1996-08-29
CA2211994C CA2211994C (en) 2005-08-02

Family

ID=23555920

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002211994A Expired - Fee Related CA2211994C (en) 1995-02-24 1996-02-20 Apparatus and method for canceling acoustic echoes including non-linear distortions in loudspeaker telephones

Country Status (12)

Country Link
US (1) US5680450A (en)
EP (1) EP0811288B1 (en)
JP (1) JPH11501171A (en)
KR (1) KR100400683B1 (en)
CN (1) CN1176034A (en)
AU (1) AU694622B2 (en)
BR (1) BR9607284A (en)
CA (1) CA2211994C (en)
DE (1) DE69616517T2 (en)
ES (1) ES2163005T3 (en)
FI (1) FI111310B (en)
WO (1) WO1996026592A1 (en)

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Also Published As

Publication number Publication date
FI111310B (en) 2003-06-30
BR9607284A (en) 1998-06-23
JPH11501171A (en) 1999-01-26
DE69616517D1 (en) 2001-12-06
FI973460A0 (en) 1997-08-22
KR100400683B1 (en) 2003-11-14
EP0811288A1 (en) 1997-12-10
AU4925296A (en) 1996-09-11
ES2163005T3 (en) 2002-01-16
CN1176034A (en) 1998-03-11
US5680450A (en) 1997-10-21
KR19980702166A (en) 1998-07-15
WO1996026592A1 (en) 1996-08-29
CA2211994C (en) 2005-08-02
EP0811288B1 (en) 2001-10-31
FI973460A (en) 1997-10-23
DE69616517T2 (en) 2002-05-02
AU694622B2 (en) 1998-07-23

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