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SE8205841L - echo canceller - Google Patents

echo canceller

Info

Publication number
SE8205841L
SE8205841L SE8205841A SE8205841A SE8205841L SE 8205841 L SE8205841 L SE 8205841L SE 8205841 A SE8205841 A SE 8205841A SE 8205841 A SE8205841 A SE 8205841A SE 8205841 L SE8205841 L SE 8205841L
Authority
SE
Sweden
Prior art keywords
echo
signal
generating means
preliminary
echo replica
Prior art date
Application number
SE8205841A
Other languages
Unknown language ( )
Swedish (sv)
Other versions
SE8205841D0 (en
Inventor
D A Alsberg
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 SE8205841D0 publication Critical patent/SE8205841D0/en
Publication of SE8205841L publication Critical patent/SE8205841L/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)
  • Radio Relay Systems (AREA)

Abstract

An echo canceller arrangement performs a two-stage cancellation while employing only a single echo replica generating means (18). Initially the generating means (18) generates a preliminary echo replica signal (@1(k)) in response to the application by switching means (24) of the resulting preliminary echo cancelled signal (e1(k)) to the echo replica generating means. When the controller (26) deems that sufficient cancellation has taken place ie the preliminary echo cancelled signal is reduced to a level below that at which it might wrongly be identified as near end speech by detector 30, the switching means (24) is activated to provide a final echo cancelled signal (e2(k)) to the echo replica generating means to form the second echo replica signal y2(k), the final value of the preliminary echo replica signal @1(k) being stored in RAM (28). <IMAGE>
SE8205841A 1981-10-23 1982-10-14 echo canceller SE8205841L (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US31435381A 1981-10-23 1981-10-23

Publications (2)

Publication Number Publication Date
SE8205841D0 SE8205841D0 (en) 1982-10-14
SE8205841L true SE8205841L (en) 1983-04-24

Family

ID=23219622

Family Applications (1)

Application Number Title Priority Date Filing Date
SE8205841A SE8205841L (en) 1981-10-23 1982-10-14 echo canceller

Country Status (8)

Country Link
JP (1) JPS5881345A (en)
KR (1) KR840002178A (en)
AU (1) AU8965582A (en)
DE (1) DE3238550A1 (en)
FR (1) FR2515453A1 (en)
GB (1) GB2109208A (en)
NL (1) NL8204100A (en)
SE (1) SE8205841L (en)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4605826A (en) * 1982-06-23 1986-08-12 Nec Corporation Echo canceler with cascaded filter structure
EP0117626A3 (en) * 1983-02-04 1985-12-18 Western Electric Company, Incorporated Improvements in or relating to adaptive filter arrangements
GB8423017D0 (en) * 1984-09-12 1984-10-17 Plessey Co Plc Echo canceller
CA1238381A (en) * 1985-03-14 1988-06-21 Ephraim Arnon Multi-stage echo canceller
US4868874A (en) * 1986-04-18 1989-09-19 Hitachi, Ltd. Echo canceller
US5471527A (en) 1993-12-02 1995-11-28 Dsc Communications Corporation Voice enhancement system and method
KR100586586B1 (en) * 1999-12-18 2006-06-02 주식회사 케이티 Interference Cancellation Weight Variable Method

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
US4057696A (en) * 1976-08-09 1977-11-08 Bell Telephone Laboratories, Incorporated Recursive-like adaptive echo canceller
DE3070399D1 (en) * 1980-12-06 1985-05-02 Communications Satellite Corp Improved double talk detector for echo cancellers

Also Published As

Publication number Publication date
JPS5881345A (en) 1983-05-16
FR2515453A1 (en) 1983-04-29
AU8965582A (en) 1983-04-28
SE8205841D0 (en) 1982-10-14
NL8204100A (en) 1983-05-16
DE3238550A1 (en) 1983-06-30
KR840002178A (en) 1984-06-11
GB2109208A (en) 1983-05-25

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