%-------------------------------------------------------------
%  Plots time-varying frequency response of a time-varying channel
%-------------------------------------------------------------------
tx_sig=ones(1,60000);
fadeBW1=0.1; fadeBW2=0.1;
KdB1=-100; KdB2=-100; 
tau=0.25; 
rel_PowdB=-3;

[rx_sig,chansamps] = RayleighFade(tx_sig,fadeBW1,KdB1,tau,fadeBW2,KdB2,rel_PowdB);

blksz=256;
spec3D = [];
N2=1;
for j= 0:7
    spec = zeros(blksz,1);
    for i=0:N2-1
        spec = spec + fftshift(abs(fft(rx_sig(1+(N2*j+i)*blksz:(N2*j+i+1)*blksz))));
    end
    spec = spec/(blksz*N2);
    plot3(0.1*j*ones(blksz,1),[-blksz/2:blksz/2-1]*1000/blksz,spec); hold on
    pause
end
xlabel('Time (s)')
ylabel('Frequency (Hz)')
zlabel('Amplitude Response')
grid
view(-37.5,30)