Post-Filtering for Stereo Acoustic Echo Cancellation

Authors: M. Kallinger, J. Bitzer, K.-D. Kammeyer
Abstract: The transmission of a spatial acoustical impression is one aim of high-quality video conferencing systems. Therefore, the transmission of stereo speech signals is a major task of such a device. Compared to the mono-case, specific problems arise, if an acoustic echo canceller (AEC) is one component of the transmission device. Its echo attenuation in the receiving room degrades, if spatial statistics in the sending room vary. Simulation results indicate that short echo cancellers are less sensitive regarding this "stereo problem". However, to achieve sufficient echo attenuation a post-filter should be applied. In this paper, we introduce a new method to design a post-filter for stereo acoustic echo cancellation. A vital task during the design procedure is the estimation of the residual echo's power spectral density (PSD) at the output of the stereo acoustic echo canceller (Stereo AEC). This estimate is sensitive regarding the "stereo problem", too. Therefore, we show up an effective way to increase its robustness and give a theoretical foundation. The result is a combination of a short Stereo AEC and a post-filter, which reveals less and shorter degradation of echo attenuation after spatial modifications in the sending room than a long (Stereo AEC), which shows the same steady-state performance.
Document type: Conference Paper
Publication: Kyoto, Japan, 8. - 11. September 2003
Conference: International Workshop on Acoustic Echo and Noise Control (IWAENC 03)
Index: 212
IWAENC_2003_kallinger.pdf111 KB
Last change on 24.04.2008 by Admin
AIT ieee GOC tzi ith Fachbereich 1
© Department of Communications Engineering - University of BremenImprint / Contact