线性调频信号的压缩以及加窗处理

%线性调频信号的实部和虚部及时域脉压输出 clear all; clc; T=16e-6; B=5e6; K=B/T; fs=6*B; Ts=1/fs; N=T/Ts; t=-T/2:T/(N-1):T/2; s=exp(j*pi*K*t.^2); y=conv(s,conj(s)); len=length(y); t1=-T/2:T/(len-1):T/2; figure;plot(t,real(s));grid on;axis([-1.2e-5 1.2e-5 -1 1]);xlabel('时间(s)');ylabel('幅度');title('LFM信号的I路'); figure;plot(t,imag(s));grid on; axis([-1.2e-5 1.2e-5 -1 1]);xlabel('时间(s)');ylabel('幅度');title('LFM信号的Q路'); figure;plot(t1,20*log10(abs(y)/max(abs(y))));grid on;axis([-1.2e-5 1.2e-5 -90 0]);xlabel('时间(s)');ylabel('幅度(dB)');title('时域脉压后的波形(未加权)'); subplot(311);plot(t,real(s));grid on;xlabel('time(s)');ylabel('amplitude(dB)');title('real part of LFM:T=16us,B=4MHz');axis([-T/2 T/2 -1 1]); subplot(312);plot(t,imag(s));grid on;xlabel('time(s)');ylabel('amplitude(dB)');title('image part of LFM:T=16us,B=4MHz');axis([-T/2 T/2 -1 1]); subplot(313);plot(t1,20*log10(abs(y)/max(abs(y))));grid on;axis([-1.2e-5 1.2e-5 -90 0]);xlabel('时间(s)');ylabel('幅度(dB)');title('时域脉压后的波形(未加权)');

% 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（196）s_realzeros（196）];
S_Q=[zeros（196）s_imagezeros（196）];
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_I12）;
% miffile（‘E:\mydesigns\lfm_match_64\mif\lfm_i.mif‘S_I_bd12256）;
% S_Q_bd=y2b（S_Q12）;
% miffile（‘E:\mydesigns\lfm_match_64\mif\lfm_q.mif‘S_Q_bd12256）;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%************************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_df_d）））;
yham=fix（abs（conv（s_dfham_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（t120*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（t220*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]）;
%*************************************

 属性            大小     日期    时间   名称
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     文件       2589  2007-06-28 10:19  lfm\LFM_4_16.m

     文件       1051  2007-07-03 13:59  lfm\LFM_PC1.m

     文件        877  2007-06-23 16:07  lfm\LFM_window3.m

     目录          0  2009-08-28 15:20  lfm

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