speed_distant.m

单脉冲雷达中频目标测速

clear all
a=1;
Bi=[ -0.000046451962915,	-0.00075518384827	,-0.000135308415921,	0.002841555023619	,0.00084437987058	,-0.007634010375115,	-0.002839935656942	,0.017363950908455	,0.007712529489581	,-0.038285191153445	,-0.021562253256757	,0.115631928738445	,0.24000074917771	,0.192654053061175	,0.036063683235075	,-0.045213871437468	,-0.015108046955929	,0.019192080579196	,0.007479138501009	,-0.008227322716728	,-0.003467948663973	,0.003044762311011	,0.001333679741865	,-0.000823931106908	,-0.000362828687586	,0.000096763709473];
Bq=[0.000096763709473,	-0.000362828687586	,-0.000823931106908	,0.001333679741865	,0.003044762311011,	-0.003467948663973,	-0.008227322716728	,0.007479138501009	,0.019192080579196	,-0.015108046955929	,-0.045213871437468	,0.036063683235075	,0.192654053061175	,0.24000074917771	,0.115631928738445	,-0.021562253256757	,-0.038285191153445	,0.007712529489581	,0.017363950908455	,-0.002839935656942	,-0.007634010375115	,0.00084437987058	,0.002841555023619	,-0.000135308415921	,-0.00075518384827	,-0.000046451962915];

f0=60*10^6-390.625*40;
fs=48*10^6;
n=240*8192*4;

signal=zeros(1,80*12*8192);

%设置回波脉冲位置
for i=1:8192
    for k=1:12
        signal((i-1)*960+12*66+8+k)=cos(2*pi*f0*((i-1)*960+12*66+8+k)*(1/fs));
    end
end

%高斯白噪声
signal=signal+20*rand(1,n);

%奇偶抽取
num_i=1:2:(240*8192*4-1);
num_q=2:2:(240*8192*4);
signal_i_temp=signal(num_i);
signal_q_temp=signal(num_q);

%符号变换
k=1:(240*8192*2);
signal_i=((-1).^(k+1).*signal_i_temp(k));
signal_q=((-1).^(k).*signal_q_temp(k));

%多相滤波
Yi=filter(Bi,a,signal_i);
Yq=filter(Bq,a,signal_q);

%修正延迟
Yi(1:12)=[];
Yi=[Yi,zeros(1,12)];
Yq(1:12)=[];
Yq=[Yq,zeros(1,12)];

%2倍抽取
kk=0:2:(240*8192*2-2);
Yii=Yi(kk+1);
Yqq=Yq(kk+1);

i=1:(80*8192);
Yii_1=Yii(3*i-2)+Yii(3*i-1)+Yii(3*i);
A=reshape(Yii_1,80,8192);

i=1:(80*8192);
Yqq_1=Yqq(3*i-2)+Yqq(3*i-1)+Yqq(3*i);
A1=reshape(Yqq_1,80,8192);

sepctrum=zeros(80,128); 
for p=1:80
    B=A(p,:);
    C=reshape(B,128,64);
    D=C';
    B1=A1(p,:);
    C1=reshape(B1,128,64);
    D1=C1';
    E=D+j*D1;    
    for i=1:64
        sepctrum(p,:)=sepctrum(p,:)+abs(fft((E(i,:).*(hann(128)'))));
    end

end

figure(1);
mesh(sepctrum);
xlabel('速度对应频率点数N：1-128');
ylabel('距离对应距离门数n：1-80');
zlabel('视频信号幅度');