eps_pnl.m

盲分离算法

% CALCULATION OF EPSILON ( algorithm : x(t+1)=x(t)+nu*epsilon(x(t)) )

%-------------------------------------------------------------------------------
%	y  =	output matrix (nsrc-by-T)
%	x  = 	imput matrix (nsrc-by-T)
%   alpha  =	sum(psi(yi)*bik,i) (nsrc-by-T)
%-------------------------------------------------------------------------------

% Grenoble, December 2000
% This work has been partly funded by the European project BLIS (IST-1999-14190)


function [y]=eps_pnl(alpha,x)

% initialisations
sigma=0.3;
[nsrc,T]=size(x);
y=zeros(nsrc,T);

for i=1:nsrc
   M=x(i,:)'*ones(1,T);				% matrix (T-by-T)
   M=M-M';					% M(k,j)=xi(k)-xi(j)
   z=(2/sqrt(pi))*exp(-(M/sigma).^2);		% Gauss function
   u=(-2*M.*z)/(sigma^2);
			% z derivative
   y(i,:)=-(z'*alpha(i,:)'+u'*ones(T,1))';	% vector :1-by-T
end;

y=y/T;						% mean