ruili.m

瑞利信 道仿真瑞利信 道仿真

clear; 
clc; 
N=5000;                      %Number of paths 
t=0.0001:10/N:10;              %Time range 
fc=900*10.^6;                %Carrier frequency 
wc=2*pi*fc;                  
v=30/3600;                   %Receiver speed[km/h] 
c=300*10^3;                  %Light speed 
wm=wc*(v/c);                   %Maximum shift 
fm=wm/(2*pi);                %Doppler shift 
for i=1:N 
   A(i)=(2*pi/N)*i;          %Azimuthal angles 
   wn(i)=wm*cos(A(i)); 
   O(i)=(pi*i)/(N+1); 
   xc(i)=2*cos(wn(i)*t(i)).*cos(O(i))+cos(wm*t(i)); 
  xs(i)=2*cos(wn(i)*t(i)).*sin(O(i)); 
 T(i)=(1/(2*N+1)^0.5).*(xc(i)+j*xs(i));%Complex envelope 
end 
 M=mean(abs(T));               %Mean 
 MdB=20*log10(M); 
 TdB=floor(20*log10(abs(T)));     %Field [dB] 
 z1=hist(abs(T)); 
 z=hist(TdB,9); 
n=0; 
for k=1:9 
   n=n+z(k); 
end 
     for j=1:9 
           P(j)=z(j)/n; 
       end 
  f(1)=P(1); 
            for x=2:9 
               f(x)=f(x-1)+P(x); 
                 F(10-x)=f(x); 
             end 
plot(z1)                          %Distribution chart 
title('Rayleigh’s distribution'); 
pause 
semilogy(t,abs(T)/max(abs(T)),'r') %Fading graphic 
title('Received field'); 
ylabel('Received field intensity'); 
xlabel('time'); 
grid on 
pause 
loglog(100*F,'m');%Indicates the probability of exceed a given attenuation 
title('Probability of exceed a given attenuation (%)');