Efficient Multichannel NLMS Implementation for Acoustic Echo Cancellation

Fredric Lindstrom1, Christian Schüldt2, Ingvar Claesson2
1Konftel AB, Research and Development, Umea, Sweden
2Department of Signal Processing, Blekinge Institute of Technology, Ronneby, Sweden

Tóm tắt

An acoustic echo cancellation structure with a single loudspeaker and multiple microphones is, from a system identification perspective, generally modelled as a single-input multiple-output system. Such a system thus implies specific echo-path models (adaptive filter) for every loudspeaker to microphone path. Due to the often large dimensionality of the filters, which is required to model rooms with standard reverberation time, the adaptation process can be computationally demanding. This paper presents a selective updating normalized least mean square (NLMS)-based method which reduces complexity to nearly half in practical situations, while showing superior convergence speed performance as compared to conventional complexity reduction schemes. Moreover, the method concentrates the filter adaptation to the filter which is most misadjusted, which is a typically desired feature.

Tài liệu tham khảo

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