gain.m

JAKES 模型的具体实现,应用瑞利衰落信道的特性

function[raleigh]=Gain(Fd,N)
%%	Producing a raleigh distribution with given Doppler frequency Fd;
%% 	N>10000,small N will distroy the gaussion of WGN;

Fs=256000;                    %% channel sample rate;
sgma=1;
tmax=40/(2*pi*Fd);            %% 20dB time point;
r=ceil(64/(2*tmax));          %% symbol rate of the gaussian data;
rn=ceil(r*N/Fs);              %% the numble of gaussion noise;             
    
L=Fs/r;                       %   interpolation factor;          
gnr=WGN(1,rn,0);               %   white gaussion noise;
gni=WGN(1,rn,0);               %   white gaussion noise;
gn=gnr+j*gni;

Jakes=Jfilter(Fd);            %   Jakes' filter with Doppler frequency Fd;
J=conv(gn,Jakes);             %   Doppler filter;
J=abs(J);
J1=J(33:(rn+32));             %   deleting the head and the tail;
JN=sqrt(var(J1));
J1=J1/JN;
m=1:rn;                       %% interpolation with factor L;
n=1:1/L:rn;
raleigh=spline(m,J1,n);       %% raleigh data with Fd and channel sample rate;
size(raleigh)