线性调频信号

图单平面振幅和差单脉冲雷达简化方框图

t=0:0.01*10^(-6):0.1*10^(-3);

N=length(t);

x1=randn(1,N);

x2=randn(1,N);

figure(1);subplot(211);plot(t,x1);

title('高斯信号','color','b');

subplot(212);plot(t,x2);

x2=3*(1+1/3*x2).*cos(1e10*t);

x1=3*(1+1/3*x1).*cos(1e10*t);

s1=sinc(t-pi/6);

s2=sinc(t+pi/6);

s3=s1+s2;

s4=s1-s2;

x1=x1.*s3;

x2=x2.*s4;

figure(2);subplot(211);plot(t,x1);

title('调制回波输出信号','color','b');

subplot(212);plot(t,x2);

x2=2*x2;

x1=2*x1;

figure(3);subplot(211);plot(t,x1);

title('高放输出信号','color','b');

subplot(212);plot(t,x2);

x2=6*(1+1/3*x2).*cos(1.003*1e10*t);

x1=6*(1+1/3*x1).*cos(1.003*1e10*t);

figure(4);subplot(211);plot(t,x1);

title('混频输出信号','color','b');

subplot(212);plot(t,x2);

r=fir1(1000,[0.5,0.7],'bandpass');

h1=fftfilt(r,x1);

h2=fftfilt(r,x2);

figure(5);

subplot(211);plot(t,h1);

title('经过中放后的两路信号','color','b'); subplot(212);plot(t,h2);

for i=1:N;

if(h1(i)<0)

h1(i)=0;

end

end

for i=1:N;

if(h2(i)<0)

h2(i)=0;

end

end

j=fir1(10000,0.02,'low');

J1=fftfilt(j,x1);

J2=fftfilt(j,x2);

figure(6);

subplot(211);plot(t,J1);

title('经过检波后的两路噪声信号','color','b') subplot(212);plot(t,J2);

s1=J1.*80;

s2=J2.*80;

figure(7);

subplot(211);plot(t,s1);

title('经过视放后的两路信号','color','b') subplot(212);plot(t,s2);

t1=s2./s1;

figure(8);plot(t,t1);

title('经过相除后的信号','color','b')