EUROSPEECH 2001 Scandinavia
7th European Conference on Speech Communication and Technology

Aalborg, Denmark
September 3-7, 2001


Equivalence between Frequency Domain Blind Source Separation and Frequency Domain Adaptive Null Beamformers

Shoko Araki (1), Shoji Makino (1), Ryo Mukai (1), Hiroshi Saruwatari (2)

(1) NTT Communication Science Laboratories, Japan
(2) Nara Institute of Science and Technology, Japan

Frequency domain Blind Source Separation (BSS) is shown to be equivalent to two sets of frequency domain adaptive microphone arrays, that is, Adaptive Null Beamformers (ANB). The unmixing matrix of the BSS and the filter coefficients of the ANB converge to the same solution in the mean square error sense if the two source signals are ideally independent. This understanding clearly explains the poor performance of the BSS in a real room with long reverberation. The fundamental difference exists in the adaptation period when they should adapt. That is, the ANB can adapt in the presence of a jammer but the absence of a target, whereas the BSS can adapt in the presence of a target and jammer, and also in the presence of only a target.

Full Paper

Bibliographic reference.  Araki, Shoko / Makino, Shoji / Mukai, Ryo / Saruwatari, Hiroshi (2001): "Equivalence between frequency domain blind source separation and frequency domain adaptive null beamformers", In EUROSPEECH-2001, 2595-2598.