clear;
clc;
close all;
fr=1.6e3;%脈沖重復(fù)頻率
tr=1/fr;%脈沖重復(fù)周期
fs=1e6;%采樣頻率
ts=1/fs;%采樣周期

f_doppler=800;%多普勒頻率

t=0:1/fs:tr-1/fs;%一個(gè)脈沖重復(fù)時(shí)間軸

x=ones(1,2);%回波中目標(biāo)的回波

n=length(x);
N=fs/fr;
x_1=[zeros(1,120),x,zeros(1,N-120-n)];%一個(gè)脈沖回波
x_18=repmat(x_1,1,18);%18個(gè)脈沖回波,其中兩個(gè)為填充脈沖,一個(gè)相關(guān)處理間隔為16*tr
t_18=(0:length(x_18)-1)*ts;
s_doppler=exp(j*2*pi*f_doppler*t_18);%多普勒調(diào)制信號(hào)
 %s_doppler=cos(2*pi*f_doppler*t_18);%多普勒調(diào)制信號(hào)
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_18.*s_doppler+s_noise_i+s_noise_q*j;%附帶多普勒的動(dòng)目標(biāo)回波
 %y=x_18;
 subplot(211)
 plot(t_18,real(y));
 subplot(212)
 plot(t_18,imag(y));
%%%%%%%%%%%%%%固定雜波對(duì)消處理%%%%%%%%%%%%%%%%%%%%
yt=reshape(y,length(y)/18,18)';
for i=1:16
      s_mti(i,:)=yt(i,:)+yt(i+2,:)-2*yt(i+1,:);%三脈沖對(duì)消
%      s_mti(i,:)=yt(i,:)-yt(i+1,:);%兩脈沖對(duì)消
end
% s_mti=s_mti/max(max(s_mti));
% s_mti=yt(1:16,:);
%%%%%%%%%%%%%%%%%%%%采用FFT進(jìn)行MTD處理%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
M=16;
L=length(s_mti);
for i=1:L
    s_temp=s_mti(:,i);%不加權(quán)
  % s_temp=s_mti(:,i).*hamming(M);%Hamming 加權(quán)FFT
  %     s_temp=s_mti(:,i).*chebwin(M);%切比雪夫 加權(quán)FFT
    s_mtd(:,i)=fft(s_temp,M);
end;
figure
t=0:ts:(length(s_mtd)-1)*ts;
subplot(241),plot(t,abs(s_mtd(1,:))),title('（第0通道）');
subplot(242),plot(t,abs(s_mtd(2,:))),title('（第1通道）');
subplot(243),plot(t,abs(s_mtd(3,:))),title('（第2通道）');
subplot(244),plot(t,abs(s_mtd(4,:))),title('（第3通道）');
subplot(245),plot(t,abs(s_mtd(5,:))),title('（第4通道）');
subplot(246),plot(t,abs(s_mtd(6,:))),title('（第5通道）');
subplot(247),plot(t,abs(s_mtd(7,:))),title('（第6通道）');
subplot(248),plot(t,abs(s_mtd(8,:))),title('（第7通道）');
figure
subplot(241),plot(t,abs(s_mtd(9,:))),title('（第8通道）');
subplot(242),plot(t,abs(s_mtd(10,:))),title('（第9通道）');
subplot(243),plot(t,abs(s_mtd(11,:))),title('（第10通道）');
subplot(244),plot(t,abs(s_mtd(12,:))),title('（第11通道）');
subplot(245),plot(t,abs(s_mtd(13,:))),title('（第12通道）');
subplot(246),plot(t,abs(s_mtd(14,:))),title('（第13通道）');
subplot(247),plot(t,abs(s_mtd(15,:))),title('（第14通道）');
subplot(248),plot(t,abs(s_mtd(16,:))),title('（第15通道）');
figure
plot(max(abs(s_mtd)))
figure
plot(0:15,(max(abs(s_mtd'))))