Title:
ADAPTIVE FILTER AND ECHO CANCELLER HAVING SAME
Document Type and Number:
WIPO Patent Application WO/2010/055650
Kind Code:
A1
Abstract:
Provided is an adaptive filter which can prevent increase of an adaptation error in a double talk state without requiring arrangement of a double talk detection circuit. The adaptive filter includes a tap coefficient setting unit (202) which uses: a delay circuit (301) and a multiplier (302) for calculating a numerator term of an update coefficient Δwn [i] by using an input signal x[n] and an error signal e[n]; and a multiplier (303), a multiplier (304), an adder (305), an averaging circuit (306), and an adder (307) for calculating a normalization denominator term of the update coefficient Δwn [i]. Moreover, the tap coefficient setting unit (202) uses a reciprocal calculation circuit (308) and a multiplier (309) for calculating an update coefficient Δwn [i] by dividing the numerator term by the normalization denominator term. Furthermore, the tap coefficient setting unit (202) uses a multiplier (310), an adder (311), and a delay circuit (312) for adding the update coefficient Δwn [i] multiplied by step size 2μ to the tap coefficient wn[i], so as to generate a tap coefficient wn+1 [i] after the update.
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Inventors:
YAMAGUCHI, Akio (())
Application Number:
JP2009/006017
Publication Date:
May 20, 2010
Filing Date:
November 11, 2009
Export Citation:
Assignee:
Yugengaisya Cepstrum (Excellent Seisekisakuragaoka 402, 33-1 Renkouji 2-chome, Tama-sh, Tokyo 21, 〒2060021, JP)
有限会社ケプストラム (〒21 東京都多摩市連光寺２丁目３３番地１号エクセレント聖蹟桜ヶ丘４０２ Tokyo, 〒2060021, JP)
有限会社ケプストラム (〒21 東京都多摩市連光寺２丁目３３番地１号エクセレント聖蹟桜ヶ丘４０２ Tokyo, 〒2060021, JP)
International Classes:
H04B3/23; H03H21/00; H04R3/02
Attorney, Agent or Firm:
WASHIDA, Kimihito (5th Floor, Shintoshicenter Bldg. 24-1, Tsurumaki 1-chome, Tama-sh, Tokyo 34, 〒2060034, JP)
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