jackes.m

Modelo de Jakes para se&ntilde ales

clear all 
close all

%function [h]=jacks_model(fm,M,dt,N) 
%jacks_model(0.02, 64, 0.1, 1024);
%define variables: 
%fm--maximum doppler shift 
fm=0.02;
%M--the number of sinusoids,number of scatterers  
M=64;
%dt -- one symbol duration in second 
dt=0.1;
%N -- the length of the fading sequence in symbol, sampling point? 
N=1024;

T=(N-1)*dt;  %%%m=128;      
t=0:dt:T;    %%%t=linspace(0,3,m); 
w=2*pi*fm; 
x=0; 
y=0; 
alpha=pi*(M+1)/(4*M+1);    %alpha=beita_(M+1) 
for n=1:M 
 beita_n=pi*n/(4*M+1);      % no cross-correlation 
 alpha_n=(2*pi*n-pi+(2*pi*rand-pi))/(4*M);    % the AoAs of the nth ray  
 x=x+cos(beita_n)*cos(w*t*cos(alpha_n)); 
 y=y+sin(beita_n)*cos(w*t*cos(alpha_n)); 
end 
% generate a complex-valued sequence 
% its amplitude is Rayleigh distributed 
% its angle is uniformly distributed 
h=(sqrt(2)*x+cos(alpha)*cos(w*t))+j*(sqrt(2)*y+sin(alpha)*cos(w*t)); 
%plot(abs(h)); 
[corr00,xxx]=xcorr(h,'coeff'); 
xx2=find(xxx>=0); 
figure()
plot(xxx(xx2),corr00(xx2));
figure()
plot(10*log10((abs(xcorr(h))).^2));
figure
plot(10*log10((abs(fft(h))).^2));    %power spectrum density 
figure()
plot(abs(ifft(fft(h))));