rayleigh_generater.m

例程中包含了matlab仿真的瑞利衰落信道产生

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 (%)');