boc_bak.m

几个BOC 信号的分析例程

M=2;
N=1;
fs=80e6;
t=0:1/fs:10000/fs;
f0=1.023e6;
code=cacode(1,N*1.023e6, fs,10000,0);
x=2*pi*f0*M*t(1:length(code));

Xnm=code.*exp(j*x);
Xnm2=code.*sign(exp(j*x));%sign(sin(x))+j*sign(cos(x))

CnmO=code.*sign(sin(x));
CnmQ=code.*sign(cos(x));


f = [0 0.02 0.02 1]; m = [1 1 0 0];
b = fir2(30,f,m);
%Cnm=filter(b,1,CnmO);
Cnm=CnmO;
figure(1)
subplot(2,1,1);
tmp=abs(fft(Xnm));
plot(20*log10(tmp));
subplot(2,1,2);
tmp=abs(fft(Cnm));
plot(20*log10(tmp));

figure(2)
xc1=abs(xcorr(Cnm,Xnm2));
xc2=abs(xcorr(Cnm,CnmO));
xc3=abs(xcorr(Cnm,CnmQ));
xc4=xcorr(Cnm,code);
xias=((9900:10100)-10000)*1.023/80;
plot(xias,xc2(9900:10100),xias,xc3(9900:10100),xias,xc1(9900:10100));
figure(3)
plot(xias,sqrt(xc2(9900:10100).^2+xc3(9900:10100).^2),xias,xc4(9900:10100));