线性调频信号的压缩以及加窗处理

% B=4M T=16us 1倍采样率 12位定点 clear all; clc; B=4e6; T=16e-6; K=B/T; fs=B; Ts=1/fs; N=round(T/Ts); t=-T/2:1/fs:T/2-1/fs; s=exp(j*pi*K*t.^2); f=conj(s); %线性调频信号的匹配滤波器 fham=f.*hamming(N)'; %加海明窗后的匹配滤波器 %%%%%%%%%%%%%%%%%%%%%%%%浮点到定点转换%%%%%%%%%%%%%%%%% s_real=real(s); s_image=imag(s); S_I=[zeros(1,96),s_real,zeros(1,96)]; S_Q=[zeros(1,96),s_image,zeros(1,96)]; maxv=max(max(S_I),max(S_Q)); S_I=fix((2.^11-1)*(S_I/maxv)); S_Q=fix((2.^11-1)*(S_Q/maxv)); s_d=S_I+j*S_Q; %定点的线性调频信号 %%%%%%%%%%%%%%%%%%%%%%%产生mif文件%%%%%%%%%%%%%%%%%%%%%%% % S_I_bd=y2b(S_I,12); % miffile('E:\mydesigns\lfm_match_64\mif\lfm_i.mif',S_I_bd,12,256); % S_Q_bd=y2b(S_Q,12); % miffile('E:\mydesigns\lfm_match_64\mif\lfm_q.mif',S_Q_bd,12,256); %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %************************match_filter***************** f_real=real(f); f_image=imag(f); maxf=max(max(f_real),max(f_image)); f_real_d=fix((2^11-1)*(f_real/maxf)); % fid=fopen('E:\mydesigns\lfm_match_64\coef\fir_i_64.dat','w'); % fprintf(fid,'%d\n',f_real_d); % fclose(fid); f_image_d=fix((2^11-1)*(f_image/maxf)); % fid=fopen('E:\mydesigns\lfm_match_64\coef\fir_q_64.dat','w'); % fprintf(fid,'%d\n',f_image_d); % fclose(fid); f_d=f_real_d+j*f_image_d; %定点的匹配滤波器 %*************************match_filter_ham***************** fham_real=real(fham); fham_image=imag(fham); maxfham=max(max(fham_real),max(fham_image)); fham_real_d=fix((2.^11-1)*(fham_real/maxfham)); % fid=fopen('E:\mydesigns\lfm_match_64\coef\fir_ham_i_64.dat','w'); % fprintf(fid,'%d\n',fham_real_d); % fclose(fid); fham_image_d=fix((2.^11-1)*(fham_image/maxfham)); % fid=fopen('E:\mydesigns\lfm_match_64\coef\fir_ham_q_64.dat','w'); % fprintf(fid,'%d\n',fham_image_d); % fclose(fid); fham_d=fham_real_d+j*fham_image_d; %定点的加海明窗后的匹配滤波器 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% ya=fix(abs(conv(s_d,f_d))); yham=fix(abs(conv(s_d,fham_d))/2.^12); l1=length(ya); t1=-T/2:T/(l1-1):T/2; l2=length(yham); t2=-T/2:T/(l2-1):T/2; figure; subplot(211);plot(t1,20*log10(ya/max(ya)));grid on;xlabel('时间(s)');ylabel('幅度(dB)');title('未加窗时时域脉压输出');%axis([-T/2 T/2 -90 0]); subplot(212);plot(t2,20*log10(yham/max(yham)));grid on;xlabel('时间(s)');ylabel('幅度(dB)');title('加窗(海明窗)后的脉压输出');%axis([-T/2 T/2 -90 0]); %*************************************