. " ( t ) ) + ( n 1 ??? ( t ) n 2 ??? ( t ) ??? n k ??? ( t ) ) = ??? x ??? ( t ) = ??? y ??? ( t ) + n ??? ( t ) = ??? As ??? ( t ) + n ??? ( t ) , m < k [0100] Here, x(t) is an instantaneous linear mixture of the source signals and additive noise, y(t) is the same linear mixture without the additive noise, n(t) is environmental noise modeled as Gaussian noise, A is an unknown mixing matrix, and s(t" . . .