signature.m

Signature estimation using LMS algorith for CDMA systems

function [W] = signature(snr_in_dB,h,B)
E = 1; numoferr = 0;
SNR = 10^(snr_in_dB/10);         % signal to noise ratio
sgma = (E/sqrt(2*SNR));
w1 = -1*[1 -1 1 -1]';N = 4;
w2 = -1*[1 1 -1 1]';w3 = w1;w4 = w1;
W = [w1 w2 w3 w4];
signat = 0.5*hadamard(4);            % using columns of hadamard matrix as spreading code
N=800;
for i=1:N
    r = signat*B(:,i) + sgma*(randn(4,1));  
    err = [];
    x = .005*[0.1 0.2 0.3 0.1];
    mu = diag(x);
    err =  B(:,i) - (W'*r);
    W = W - 2*mu*r*err';
    %E(i) = err;
    %E1(i) = error1;
    %MSE1(i) = mean(E1(1:i).*E1(1:i));
    %E2(i) = error2;
    %MSE2(i) = mean(E2(1:i).*E2(1:i));
end
W = [w1 w2 w3 w4];
%if (snr_in_dB == 10)
%    figure;plot(MSE1);title('MSE');
%    figure;plot(MSE2);title('MSE');
%end