%implements a frequency domain adaptive LMS filter, using the overlap save
%method
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%restrictions: x & d = column vector
function [y,e,w] = fdaf_lms(x,d,adapt)

%get global variables
global N;global mu;global W;global k;global g;

%step that updates the output of the filter
X = diag(fft(x));
Y = X*W;%W has to be a column vector
y = k*ifft(Y)';y = y';%k has to be a row vector

if (adapt == 1)
    %step that computes the future filtercoefficients
    e = d-y;
    E = fft([zeros(N);e]);
    grad = g*ifft(X'*E);
    W = W + 2*mu*eye(N)*fft(grad);
end

w = W