finefrequency.m

来自「利用自己仿真产生的卫星数据」· M 代码 · 共 35 行

function dfreq=finefrequency(CA,fr,inputdata,datalength,k)
global channel;
global num;
global datanum;
global fs;

ts=1/fs;

stripcode=inputdata.*CA;
fstripcode=stripcode.*exp(j*2*pi*fr*ts*[0:8*datanum-1]);
ang50=diff(angle(sum(reshape(fstripcode,datanum,8))));
ang=ang50;

 for counter=1:7
     if abs(ang(counter))>(2.3*pi/5),
         if ang(counter)>0,
             ang(counter)=ang(counter)-2*pi;
         else
             ang(counter)=ang(counter)+2*pi;
         end
         if abs(ang(counter))>(2.3*pi/5),
             %ang(counter)=ang(counter)-pi;
             if ang(counter)>0,
                 det(counter)=ang(counter)-pi;
             else
                 det(counter)=ang(counter)+pi;
             end
         else
             det(counter)=ang(counter);
         end
     else
         det(counter)=ang(counter);
     end
 end
 dfreq=mean(det)*1000/(2*pi);