gerchberg.m

Analytical constant-modulus algorithm, to separate linear combinations of CM sourcesThe algorithm i

function [s,w] = gerchberg(X,w0,numiter)
% function [s,w] = gerchberg(X,w0,numiter)
%
% Try to find a weight vector w such that
%   s = w [x(1) x(2) ... x(N)] = w X
% has constant modulus 
% 
% w0: initial guess for w (or random if unspecified)
% numiter: number of iterations (30)

[m,N] = size(X);

if (nargin <= 1),
    w0 = randn(1,m);	% initial guess of the weight vector w
end
if (nargin <= 2),
    numiter = 30;
end
    

Xi = pinv(X);

w = w0;
for k = 1:numiter,
  y = w*X;
  s = y./abs(y);
  w = s*Xi;
end;

s = w*X;