DocumentCode :
1538282
Title :
A robust echo canceler for acoustic environments
Author :
Doherty, John F. ; Porayath, Rajiv
Author_Institution :
Dept. of Electr. Eng., Pennsylvania State Univ., University Park, PA, USA
Volume :
44
Issue :
5
fYear :
1997
fDate :
5/1/1997 12:00:00 AM
Firstpage :
389
Lastpage :
396
Abstract :
This paper presents a novel acoustic echo canceler for teleconference and speakerphone systems based upon input orthogonalization and spread spectrum communication techniques. The new echo canceler represents a significant departure from traditional methods of removing acoustical echo and solves the open problem of echo cancellation during double-talk transmission. A decorrelation based adaptive filtering algorithm is introduced and its performance studied. A contraction mapping principle is applied to obtain a tight bound on the step size for the convergence of the adaptive algorithm. In conjunction, a direct sequence spread spectrum correlation technique is used to estimate the room impulse response during double-talk. Both components of the echo canceler rely on an innocuous wide-band training signal which is transmitted into the room along with the speech. The new echo canceler was implemented on a TMS320C30 DSP processor and experimental results are presented. The echo canceler was found to give excellent performance for all operating conditions, including during double-talk transmission
Keywords :
adaptive filters; echo suppression; spread spectrum communication; teleconferencing; TMS320C30 DSP processor; acoustic environments; acoustical echo; contraction mapping principle; decorrelation based adaptive filtering algorithm; direct sequence spread spectrum correlation technique; double-talk transmission; input orthogonalization; robust echo canceler; room impulse response; speakerphone systems; spread spectrum communication techniques; teleconference systems; wide-band training signal; Adaptive algorithm; Adaptive filters; Convergence; Decorrelation; Echo cancellers; Filtering algorithms; Robustness; Spread spectrum communication; Teleconferencing; Wideband;
fLanguage :
English
Journal_Title :
Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on
Publisher :
ieee
ISSN :
1057-7130
Type :
jour
DOI :
10.1109/82.580846
Filename :
580846
Link To Document :
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