加窗都脉冲压缩的影响

加窗都脉冲压缩的影响0.511.522.533.5x10-4-60-50-40-30-20-100t-seconds幅度db脉冲压缩输出对比未加窗加hamming窗0.511.522.533.5x10-4-60-50-40-30-20-100t-seconds幅度db脉冲压缩输出对比未加窗加hanning窗0.511.522.533.5x10-4-60-50-40-30-20-100t-seconds幅度db脉冲压缩输出对比未加窗加kaiser窗0.511.522.533.5x10-4-70-60-50-40-30-20-100t-seconds幅度db脉冲压缩输出对比未加窗加blackman窗加各种窗函数脉压的结果对比主瓣宽度峰值主副瓣比主瓣损失不加窗1.8us22.77dB10.83dB0.00dB加hamming窗2.0us20.26dB18.96dB2.51dB加hanning窗2.2us19.99dB20.67dB2.78dB加kaiser窗1.9us21.78dB15.66dB0.99dB加blackman窗3.1us19.20dB20.16dB3.67dB可见加窗脉压对副瓣抑制比较好。程序如下：closeall;clearall;eps=1e-10;%=====================================================================%雷达参数%%====================================================================C=3.0e8;%光速(m/s)Lambda=0.03;%雷达工作波长f0=C/Lambda;BandWidth=1.0e6;%发射信号带宽TimeWidth=200e-6;%发射信号时宽mu=BandWidth/TimeWidth%调频率Fs=2*BandWidth;%采样频率Ts=1/Fs;Ns=fix(Fs*TimeWidth);%计算一个脉冲周期的采样点数；N=1024;%FFT点数t=0:Ts:TimeWidth-Ts;%====================================================================y=exp(j*pi*mu*t.^2);yfft=fft(y,N);h=zeros(1,Ns);fori=1:Nsh(i)=conj(y(Ns-i+1));endhfft=fft(h,N);%匹配滤波器的频域响应ycomp=abs(ifft(yfft.*hfft));%脉冲压缩maxval=max(ycomp);ycomp=eps+ycomp./maxval;%利用最大值归一化ycomp_db=20*log10(ycomp);%取对数%%%%%%%%%%%%%%加窗处理%%%%%%%win=hamming(Ns)';h_w=h.*win;%加窗hfft_w=fft(h_w,N);%加窗的匹配滤波器的频域响应ycomp_w=abs(ifft(yfft.*hfft_w));%脉冲压缩maxval1=max(ycomp_w);val=ycomp_w;ycomp_w=eps+ycomp_w./maxval;%利用ycomp的最大值归一化ycomp_w1=eps+val./maxval1;%利用ycomp_w的最大值归一化ycomp_w_db=20*log10(ycomp_w);%取对数ycomp_w1_db=20*log10(ycomp_w1);%取对数%%%%%%%%%%%%%%%%tt=0:Ts:2*TimeWidth-Ts;figure(1)plot(tt,ycomp_db(1:2*Ns),'b')axis([.2*TimeWidth1.8*TimeWidth-600])xlabel('t-seconds');ylabel('幅度db')title('未加窗的脉冲压缩输出')gridonfigure(2)plot(tt,ycomp_w1_db(1:2*Ns),'r')axis([.2*TimeWidth1.8*TimeWidth-600])xlabel('t-seconds');ylabel('幅度db')title('加窗的脉冲压缩输出')gridonfigure(3)plot(tt,ycomp_db(1:2*Ns),'b',tt,ycomp_w_db(1:2*Ns),'r')axis([.2*TimeWidth1.8*TimeWidth-600])xlabel('t-seconds');ylabel('幅度db')legend('未加窗','加窗');title('脉冲压缩输出对比')gridon