dpskdemod.m

实现QPSK和BPSK的调制解调程序

function [idataout,qdataout]=adpskdemod(idatain,qdatain)
phase=0.75*pi;
for i=1:length(idatain);
    a=idatain(i);
    b=qdatain(i);
    if a==0&&b==0
        current_phase=0.75*pi;
    elseif a==0&&b==1
       current_phase=1.25*pi; 
   elseif a==1&&b==1
       current_phase=1.75*pi;
   elseif a==1&&b==0
       current_phase=0.25*pi;
   end
   if current_phase<phase
       diff_phase=current_phase+2*pi-phase;
else
    diff_phase=current_phase-phase;
end
   if abs(diff_phase-0)<0.01;
       idataout(i)=0;
       qdataout(i)=0; 
   elseif abs(diff_phase-0.5*pi)<0.01;
       idataout(i)=0;
       qdataout(i)=1; 
   elseif abs(diff_phase-pi)<0.01;
       idataout(i)=1;
       qdataout(i)=1; 
   elseif abs(diff_phase-1.5*pi)<0.01;
       idataout(i)=1;
       qdataout(i)=0;  
   end
   phase=current_phase;
end