fir_mtd8.m

Moving target detection and the principle of achieving matlab

clear;
clc;
close all;
fr=1.6e3;%脉冲重复频率
tr=1/fr;%脉冲重复周期
fs=1e6;%采样频率
ts=1/fs;%采样周期

f_doppler=1000;%多普勒频率

t=0:1/fs:tr-1/fs;%一个脉冲重复时间轴

x=ones(1,2);%回波中目标的回波

n=length(x);
N=fs/fr;
x_1=[zeros(1,120),x,zeros(1,N-120-n)];%一个脉冲回波
x_8=repmat(x_1,1,8);%8个脉冲回波,一个相关处理间隔为8*tr
t_8=(0:length(x_8)-1)*ts;
s_doppler=exp(j*2*pi*f_doppler*t_8);%多普勒调制信号
 %s_doppler=cos(2*pi*f_doppler*t_8);%多普勒调制信号
randn('state', sum(100*clock));%Initialize randn to a different state each time
s_noise_i=0.1*randn(1,length(s_doppler));
randn('state', sum(100*clock));%Initialize randn to a different state each time
s_noise_q=0.1*randn(1,length(s_doppler));
y=x_8.*s_doppler+s_noise_i+s_noise_q*j;%附带多普勒的动目标回波
 %y=x_8;
 figure('Name','附带多普勒的动目标回波显示')
 subplot(211)
 plot(t_8,real(y));
 subplot(212)
 plot(t_8,imag(y));
 
%%%%%%%%%%%%%%%%%%%%  产生8个FIR滤波器的滤波器组  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
a0=[ 7.135916968387e-010,1.568395747901e-008,5.471539757694e-008,9.376656588003e-008,...
  9.376656588003e-008,5.471539757694e-008,1.568395747901e-008,7.135916968387e-010]*1e10;
n=1:8;
f=linspace(0.61,1.388,8)*pi;
fn=f'*n;
fnexp=exp(j*fn);
a08=repmat(a0,1,8);
a08=reshape(a08,8,8)';
b=a08.*fnexp;
%%%%%%%% FIR滤波器的滤波器组的频率响应曲线  %%%%%%%%%%%%
figure('Name','FIR滤波器的滤波器组的频率响应曲线');
for n=1:8
    freqz(b(n,:),1,1024,'whole',fr)
    hold on;
end
axis([0 fr -50 100]);
%%%%%%%% FIR滤波器的滤波器组的频率响应曲线  %%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%  产生8个FIR滤波器的滤波器组  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

yt=reshape(y,length(y)/8,8)';

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  采用FIR进行MTD处理  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
M=8;
L=length(yt);
for i=1:L
    s_temp=yt(:,i); 
    s_mtd(:,i)=b*s_temp;    
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%  采用FIR进行MTD处理 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


%%%%%%%%%%%%%%%%%%%%  MTD处理结果显示  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%  MTD各通道结果显示  %%%%%
t=0:ts:(length(s_mtd)-1)*ts;
figure('Name','MTD各通道结果显示')
subplot(241),plot(t,abs(s_mtd(1,:))),title('（第1通道）');
subplot(242),plot(t,abs(s_mtd(2,:))),title('（第2通道）');
subplot(243),plot(t,abs(s_mtd(3,:))),title('（第3通道）');
subplot(244),plot(t,abs(s_mtd(4,:))),title('（第4通道）');
subplot(245),plot(t,abs(s_mtd(5,:))),title('（第5通道）');
subplot(246),plot(t,abs(s_mtd(6,:))),title('（第6通道）');
subplot(247),plot(t,abs(s_mtd(7,:))),title('（第7通道）');
subplot(248),plot(t,abs(s_mtd(8,:))),title('（第8通道）');
%%%%%  MTD各通道结果显示  %%%%%

%%%%%  MTD距离维结果显示  %%%%%
figure('Name','MTD距离维结果显示');
plot(max(abs(s_mtd)))
%%%%%  MTD距离维结果显示  %%%%%

%%%%%  MTD速度维结果显示  %%%%%
figure('Name','MTD速度维结果显示')
plot(1:8,(max(abs(s_mtd'))))
%%%%%  MTD速度维结果显示  %%%%%

%%%%%%%%%%%%%%%%%%%%  MTD处理结果显示  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%