rayleigh11.m.txt

一种改进型的瑞利信道仿真模型小案例（JAKES参考模型）

%function Tk(t) =
%sqrt(1/(2N0+1)){2sum{(cos(bn)+jsin(bn)*cos(wmcos(an*t+sita_nk)}+sqrt(2)*co
%s(wm*t+sita_ok)} ( sum is fron 0 to N0) N0 = (1/2)(N/2-1)
clear all; 
close all;  
nn=5000;                      %Number of paths 
t=0.0002:1/nn:5;              %Time range ts=0.1ms
fc=900*10.^6;                %Carrier frequency 
wc=2*pi*fc;                  
v=30/3600;                   %Receiver speed[km/h] 
c=300*10^3;                  %Light speed 3*10^5 km/s
wm=wc*(v/c);                   %Maximum shift 
fm=wm/(2*pi);                %Doppler shift 
N0 = 100;
N = 2*(2*N0+1);%反射波数
 xc = zeros(1,length(t));
xs= zeros(1,length(t));
b = (2*rand(1,N0)-1)*pi;
for i=1:N0 
   A(i)=(2*pi/N)*i;          %Azimuthal angles 
   wn(i)=wm*cos(A(i)); 
  % O(i)=(pi*i)/(N+1); % beta? N0 or N?
  O(i) = b(i);% 
  aa=cos(wn(i)*t); 
   xc =xc+2*cos(O(i))*cos(wn(i)*t);%+cos(wm*t); 
  xs =xs+2*cos(wn(i)*t)*sin(O(i)); 
 %T(t)=(1/(2*N+1)^0.5).*(xc(i)+j*xs(i));%Complex envelope 
 end 
T=(1/(2*N+1)^0.5).*(xc+j*xs)+cos(wm*t);%Complex envelope 
Tt=abs(T);%/sum(abs(T));
K1=46.3+33.9*log(fc);
K2=44.9;
K3=0;%Mobile Antenna height factor
K4=0;%Okumura-Hata multiplying factor for Hms
K5=-13.8;%Effective Antenna Height Gain
K6=-6.55;%Okumura Hata multiplying factor for Log(Heff)log(d)
K7=0;%Multiplying factor for diffraction calculations
d=1;%Distance between Base Station and Mobile Station [km]
Hms=1.5;%Mobile Station Antenna Height [m] (e.g. 1.5m)
Heff=30;%Effective Base Station Antenna Height [m] (e.g. 30m)


PL=K1+K2*log10(d)+K3*Hms+K4*log10(Hms)+K5*log10(Heff)+K6*log10(Heff)*log10(d)+K7*DL+CL



 M=mean(abs(T));               %Mean 
 MdB=20*log10(M); 
 TdB=floor(20*log10(abs(T)));     %Field [dB] 
 hist(Tt,0:0.02:3)% plot pdf
 
  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 
       figure;
plot(z1)                       %Distribution chart also pdf
title('Rayleigh’s distribution'); 

figure;
% pause 
semilogy(t(1:2500),abs(T(1:2500))/max(abs(T(1:2500))),'r') %Fading graphic partly
title('Received field'); 
ylabel('Received field intensity'); 
xlabel('time'); 
grid on 
% pause 
figure;
loglog(100*F,'m');%Indicates the probability of exceed a given attenuation 
title('Probability of exceed a given attenuation (%)');