Inter-channel decorrelation by sub-band resampling in frequency domain

This paper presents a novel decorrelation procedure by frequency-domain resampling in sub-bands. The new procedure expands on the idea of resampling in the frequency domain that efficiently and effectively alleviates the non-uniqueness problem for a multi-channel acoustic echo cancellation system while introducing minimal distortion to the signal. We show in theory and verify experimentally that the amount of decorrelation in each sub-band, measured in terms of the coherence, can be controlled arbitrarily by varying the resampling ratio per frequency bin. For perceptual evaluation, we adjust the sub-band resampling ratios to match the coherence given by other decorrelation procedures. The speech quality (PESQ) score from the proposed decorrelation procedure remains high at around 4.5, which is about the highest possible PESQ score after signal modification.

[1]  G. Carter.  Coherence and time delay estimation , 1987, Proceedings of the IEEE.

[2]  J. L. Hall,et al.  Stereophonic acoustic echo cancellation-an overview of the fundamental problem , 1995, IEEE Signal Processing Letters.

[3]  Ted S. Wada,et al.  Decorrelation by resampling in frequency domain for multi-channel acoustic echo cancellation based on residual echo enhancement , 2011, 2011 IEEE Workshop on Applications of Signal Processing to Audio and Acoustics (WASPAA).

[4]  Ted S. Wada,et al.  Acoustic echo cancellation based on independent component analysis and integrated residual echo enhancement , 2009, 2009 IEEE Workshop on Applications of Signal Processing to Audio and Acoustics.

[5]  F. Wightman,et al.  The dominant role of low-frequency interaural time differences in sound localization. , 1992, The Journal of the Acoustical Society of America.

[6]  P. Welch.  The use of fast Fourier transform for the estimation of power spectra: A method based on time averaging over short, modified periodograms , 1967 .

[7]  Ted S. Wada,et al.  MULTI-CHANNEL ACOUSTIC ECHO CANCELLATION BASED ON RESIDUAL ECHO ENHANCEMENT WITH EFFECTIVE CHANNEL , 2010 .

[8]  Jacob Benesty,et al.  Stereophonic acoustic echo cancellation and two‐channel adaptive filtering: an overview , 2000 .

[9]  Walter Kellermann,et al.  Acoustic Echo Cancellation for Surround Sound using Perceptually Motivated Convergence Enhancement , 2007, 2007 IEEE International Conference on Acoustics, Speech and Signal Processing - ICASSP '07.

[10]  Yann Joncour,et al.  A stereo echo canceler with correct echo-path identification based on an input-sliding technique , 2001, IEEE Trans. Signal Process..