% simulation of Adaptive Equalization RLS
N=2000;%%%%碼元個數(shù)
K=5;%%%抽頭個數(shù)為2*K＋1
% W=3.1;
% n=[1,2,3];
% actual_isi=0.5*(1+cos(2*pi*(n-2)/W));
h=[1,zeros(1,6),0.60346,zeros(1,5),0.62736];%%%10Km信道（碼元寬度為1Ms的情況）
snr=20;%%%信噪比，注意此處信噪比為頻帶內(nèi)的而非通帶內(nèi)的
delta=1;
Num_of_realizations=100;%%%運行次數(shù)
BETA=250;
mse_av=zeros(1,N-2*K);
for j=1:Num_of_realizations,
    info=1-2*randint(1,N);
%     y=filter(actual_isi,1,info);
    y=filter(h,1,info);%%%%加多徑影響
    noise=randn(1,length(y))/10.^(snr/10);%%%%加噪聲影響
    y=y+noise;
    estimated_c=zeros(1,2*K+1);
    P=BETA*eye(11,11);  % important
        for k=1:N-2*K,
        y_k=y(k:k+2*K);
        z_k=estimated_c*y_k.';
        e_k=info(k)-z_k;
        K1=(P*y_k')/(delta+y_k*P*y_k');
        P=(P-K1*y_k*P)/delta;
        estimated_c=estimated_c+K1'*e_k;
        mse(k)=e_k^2;
    end;
    mse_av=mse_av+mse;
end
mse_av=mse_av/Num_of_realizations;
t=1:N-2*K;
% semilogy(t,mse_av)
plot(mse_av);
xlabel('迭代次數(shù)');
ylabel('MSE');
grid on ;
hold on