On the difference between updating the mixing matrix and updating the separation matrix
Jan Larsen, Ulrik Kjems and Michael Pedersen
Proceedings of ICASSP 2005
When the ICA source separation problem is solved by maximum
likelihood, a proper choice of the parameters is important.
A comparison has been performed between the use
of a mixing matrix and the use of the separation matrix as
parameters in the likelihood. By looking at a general behavior
of the cost function as function of the mixing matrix
or as function of the separation matrix, it is explained and
illustrated why it is better to select the separation matrix as
a parameter than to use the mixing matrix as a parameter.
The behavior of the natural gradient in the two cases has
been considered as well.