Development of high quality acoustic subband echo canceller using dual-filter structure and fast recursive least squares algorithm
نویسندگان
چکیده
A high quality acoustic subband echo canceller is developed based on a dual-filter structure and the fast recursive least squares (FRLS) algorithm. Methods for overcoming the instability problem of the FRLS algorithm and implementing it using the 32-bit fixed-point arithmetic are presented. A new tap-weight transfer method, which assures double talk detection, is proposed. Computer simulations demonstrate that fast convergence and fast tracking are achieved in an acoustic subband echo canceller using 32 subbands and a total of 4000-tap FIR filter for a 250ms echo path. The combined use of the FRLS algorithm in the lowest eight frequency bands and the normalized least mean square (NLMS) algorithm in the rest of the frequency bands increases convergence rate for speech signals by five to ten times, and the echo return loss enhancement (ERLE) by more than 10dB over those of using only the NLMS algorithm.
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Speech Signal Extraction A Multichannel Approach
The increasing use of modern hands free communication systems such as video conferencing, computer communications, and vehicle mounted cellular telephones brings the demand for high-quality acoustic echo cancellation up to focus. In these applications the echo path which has to be identified typically has long time duration, the order of 100 ms. For this identification the length of the filter ...
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