JPS5792927A - Echo cancelling device - Google Patents

Echo cancelling device

Info

Publication number
JPS5792927A
JPS5792927A JP16859280A JP16859280A JPS5792927A JP S5792927 A JPS5792927 A JP S5792927A JP 16859280 A JP16859280 A JP 16859280A JP 16859280 A JP16859280 A JP 16859280A JP S5792927 A JPS5792927 A JP S5792927A
Authority
JP
Japan
Prior art keywords
output
level
subtractors
subtractor
accordance
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
JP16859280A
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 JP16859280A priority Critical patent/JPS5792927A/en
Publication of JPS5792927A publication Critical patent/JPS5792927A/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

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 cancel the side tone in accordance with a line fluctuation with a simple constitution without a learning algorithm, by selecting and using plural false echo paths in accordance with line conditions. CONSTITUTION:False side tones are generated by the first and the second digital filters 12 and 13 and are subtracted from a receiving signal by the first and the second subtractors 15 and 16. Output levels of subtractors 15 and 16 are compared and decided by a level deciding device 17; and on a basis of the decision output, the output of the subtractor having a smaller level is outputted as a receiving signal, and the coefficient of the digital filter for the output of the subtractor having a larger level is switched to a coefficieot stored preliminarily in a coefficient ROM 14. This operation is repreated to eliminate the side tone while following the fluctuation of service conditions.
JP16859280A 1980-11-29 1980-11-29 Echo cancelling device Pending JPS5792927A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP16859280A JPS5792927A (en) 1980-11-29 1980-11-29 Echo cancelling device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP16859280A JPS5792927A (en) 1980-11-29 1980-11-29 Echo cancelling device

Publications (1)

Publication Number Publication Date
JPS5792927A true JPS5792927A (en) 1982-06-09

Family

ID=15870905

Family Applications (1)

Application Number Title Priority Date Filing Date
JP16859280A Pending JPS5792927A (en) 1980-11-29 1980-11-29 Echo cancelling device

Country Status (1)

Country Link
JP (1) JPS5792927A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6165629A (en) * 1984-09-07 1986-04-04 Hitachi Ltd Digital automatic hybrid circuit
US4757527A (en) * 1984-09-12 1988-07-12 Plessey Overseas Limited Echo canceller
JPH01500872A (en) * 1986-09-05 1989-03-23 リンカビット・ワイヤレス・インコーポレーテッド Linear predictive echo canceller with integrated RELP vocoder

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6165629A (en) * 1984-09-07 1986-04-04 Hitachi Ltd Digital automatic hybrid circuit
US4757527A (en) * 1984-09-12 1988-07-12 Plessey Overseas Limited Echo canceller
JPH01500872A (en) * 1986-09-05 1989-03-23 リンカビット・ワイヤレス・インコーポレーテッド Linear predictive echo canceller with integrated RELP vocoder

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