qpsk.asv

gps c/a码程序以及模拟卫星定位的源代码、地球模型

clear
close all;
sr=256000.0;
m1=2;
br=sr.*m1;
nd=1000;
ebn0=3;
IPOINT=8;



irfn=21;
alfs=0.5;
[xh]=hrollfcoef(irfn,IPOINT,sr,alfs,1);
[xh2]=hrollfcoef(irfn,IPOINT,sr,alfs,0);


nloop=100;
noe=0;
nod=0;

for iii=1:nloop
    data1=rand(1,nd*m1)>0.5;
    
    [ich,qch]=qpskmod(data1,1,nd,m1);
    [ich1,qch1]=compoversamp(ich,qch,length(ich),IPOINT);
    [ich2,qch2]=compconv(ich1,qch1,xh);
    spow=sum(ich2.*ich2+qch2.*qch2)/nd;
    attn=0.5*spow*sr/br*10.^(-ebn0/10);
    attn=sqrt(attn);
    
    
    [ich3,qch3]=comb(ich2,qch2,attn);
    [ich4,qch4]=compconv(ich3,qch3,xh2);
    syncpoint=irfn*IPOINT+1;
    ich5=ich4(syncpoint:IPOINT:length(ich4));
    qch5=qch4(syncpoint:IPOINT:length(qch4));
    
    [demodata]=qpskdemod(ich5,qch5,1,nd,m1);
    noe2=sum(abs(data1-demodata));
    nod2=length(data1);
    noe=noe+noe2;
    nod=nod+nod2;
    fprintf('%d\t%e\n',iii,noe2/nod2);
end
ber=noe/nod;
fprintf('%d\t%d\t%d\t%e\n',ebn0,noe,nod,noe/nod);
fid=fopen('BERqpsk.dat','a');
fprintf(fid,'%d\t%e\t%f\t%f\t\n',ebn0,noe/nod,noe,nod);
fclose(fid);