u7.m

基于多径传输和多普勒频移的 瑞利（Rayleigh）信道的仿真 主要考虑不同条件下的仿真

clear
f_c=1e3;                                   %carrier frequency(no modulation)
time_1 = (linspace (0, 10, 1000));         %time
signal_in = sin (2 * pi *f_c* time_1);     %sine wave
         
plot (time_1, signal_in, 'b');
grid on;           %blue=signal_in
xlabel('time');
ylabel('amplitude');
title('Rayleigh fading channel with two path sine wave input')
hold on
for ii = 1:10                                    %# iterations
    tau=round(50*rand(1,1)+1);                   % variable delay(phase shift)
    g1=1;%fixed gain
    g2=round(.5*rand(1,1)+1);                     %variable gain or attenuation
    signal_out=g1*signal_in + g2*[zeros(1,tau) signal_in(1:end-tau)];

  plot (time_1,(signal_out),'r')                  %red=signal_out
  pause (2)                                       %~ seconds
end
hold off