Blind Source Separation Coping with the
Change of the Number of Sources

Masanori Ito1, Noboru Ohnishi1, Ali Mansour2, and Mitsuru Kawamoto3,4

1 Graduate School of Information Science, Nagoya University
Furo-cho, Chikusa-ku, Nagoya,464–8603 Japan
ito-m@nagoya-u.jp

2 ENSIETA, 29806 Brest cedex 09, France

3 Advanced Industrial Science and Technology,
Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki, 305–8568 Japan

4 Bio-mimetic Control Research Center, RIKEN,
2271–120 Anagahora, Shimoshidami, Moriyama-ku, Nagoya, 463–0003 Japan


Abstract. This manuscript deals with the blind source separation problem
with an instantaneous but dynamical mixture model. This study is
limited to the case when the number of sources is time-variant. Theoretically,
when new sources are detected, a new separating matrix should be
estimated in order to extract all sources. However this effort implies an
overwhelm computational cost. Our idea consists to use the previous separating
matrix which was estimated before the appearance of the new
sources. Owing to this point, the computational time and cost can be
effectively reduced compared with the conventional separation scheme.
Our new algorithm was corroborated with many simulations. Some results
are given in the manuscript. The obtained and presented results
clearly show that the proposed method outperformed the conventional
method in processing time as well as in separation quality.
Keywords: blind source separation, time-variant system, dynamical instantaneous
mixtures, independent component analysis.