Independent Component Analysis - Chapter 16: ICA with Overcomplete Bases
Independent Component Analysis - Chapter 16: ICA with Overcomplete Bases
A difficult problem in independent component analysis (ICA) is encountered if the number of mixtures xi is smaller than the number of independent components si. This means that the mixing system is not invertible: We cannot obtain the independent components (ICs) by simply inverting the mixing matrix . Therefore, even if we knew the mixing matrix exactly, we could not recover the exact values of the independent components.