The separation of a set of observations into the constituent underlying source signals.
A New Learning Algorithm for Blind Signal Separation
S Amari, A Cichocki, H H Yang
http://papers.nips.cc/paper/1115-a-new-learning-algorithm-for-blind-signal-separation.pdf
BLIND SOURCE SEPARATION: Principal & Independent Component Analysis
G.D. Clifford
http://www.mit.edu/~gari/teaching/6.555/LECTURE_NOTES/ch15_bss.pdf