xiangganjianbo.m

雷达系统的模拟仿真对雷达的研究和发展有很重要的意义

function [I,Q]=xiangganjianbo(s,fs,f0,f1)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%相位相干检波
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
[M,N]=size(s);
i=0:M-1;
z1=cos(2*pi*f0*i/(3*fs));
z2=sin(2*pi*f0*i/(3*fs));
y1=zeros(M,N);
y2=zeros(M,N);
for i=1:N
    y1(1:M,i)=(z1.*s(1:M,i)')';
    y2(1:M,i)=(z2.*s(1:M,i)')';
end
wt1=2*pi*(4*f1)/(3*fs);%wt1=4pi/45
wt2=2*pi*(7*f1)/(3*fs);%wt2=7pi/45
th=wt2-wt1;
M1=ceil(6.6*pi/th)+1;%M1=70
%n=[0:M1-1];
wt3=(wt1+wt2)/2;%wt3=11pi/90
hd=wide(wt3,M1);
w=(hamming(M1))';
h=hd.*w;
L=length(h);
z1=zeros(M+L-1,N);
z2=zeros(M+L-1,N);
I=zeros(M,N);
Q=zeros(M,N);
K=ceil(L/2);
for i=1:N
    for j=1:10
        z1(1+(j-1)*M/10:j*M/10+L-1,i)=conv(h,y1(1+(j-1)*M/10:j*M/10,i)')';
        z2(1+(j-1)*M/10:j*M/10+L-1,i)=conv(h,y2(1+(j-1)*M/10:j*M/10,i)')';
        I(1+(j-1)*M/10:j*M/10,i)=z1(1+(j-1)*M/10+K:j*M/10+K,i);
        Q(1+(j-1)*M/10:j*M/10,i)=z2(1+(j-1)*M/10+K:j*M/10+K,i);
    end
end
w1=I(:)';
w2=Q(:)';
subplot(4,1,1);
j=0:length(w1)-1;
plot(j,w1),title('I路信号');
subplot(4,1,2);
plot(j,w2),title('Q路信号');
subplot(4,1,3);
w=w1+i*w2;
plotpu(w),title('频谱');
subplot(4,1,4);
plotpu(h),title('幅频特性');