function s = WienerARprocess (x, a, varu, varn)

N = length(x);
% for k = 1:N
%     Pss(k) = varu/norm(1+a*exp(-j*2*pi*(k-1)/N));
% end;
% Cs = real(ifft(Pss));

for k = 0:N-1
    rss(k+1) = (varu*a^k)/(1-a^2);
end;
for i = 1:N
    for j = 1:N
        Cs(i,j) = rss(abs(i-j)+1);
    end;
end;
s = (Cs*inv(Cs+varn*eye(N))*x')';