%?script?to?simulate?LFM?pulse?signal?intermediate?frequency?sample?quandrature?
%?demodulation?and?match?filter?processing.?
%
%
%?Author:?leassun
%?Institution:?NJUST?-?Department?of?E.E
%?Year:?2013
%?Version:?1.0

clc;
clear;
close?all;


f0?=?20e9;??????%?transfer?carrier?frequency
f1?=?15e6;??????%?intermediate?frequency
fs?=?20e6;??????%?sample?frequency
B?=?4e6;
T?=?16e-6;
Tprf?=?500e-6;
C?=?3e8;
K?=?B/T;

dist?=?0*20e3;
tao?=?2*dist/C;
sig?=?zeros（1Tprf*fs）;

t_wav?=?（[1:T*fs]-T*fs/2）/fs;
wav_tr?=?exp（1i*2*pi*f1*t_wav+1i*pi*K*t_wav.^2）;
wav_re?=?exp（-1i*2*pi*f0*tao）.*wav_tr;
len_wav?=?length（wav_tr）;

sop?=?floor（tao*fs）?+?1;
sig（sop:sop+len_wav-1）?=?real（wav_tr）;

figure（‘Name‘‘Receive?Echo?Signal‘）;
plot（real（sig））

%%?intermediate?frequency?sample?quandrature?demodulation
sigout?=?Sub_InterFreqQuadDemod（sigf1fs）;

figure（‘Name‘‘Intermediate?frequency?quandrature?demodulation?output‘）;
subplot（211）;plot（real（sigout））;title（‘Real?signal‘）;
subplot（212）;plot（imag（sigout））;title（‘Image?signal‘）;


%%?match?filter
wav_ref?=?exp（-1i*pi*K*t_wav.^2）;
wav_ref?=?wav_ref（1:2:end）;
%?fs2?=?fs/2;
%?t_ref?=?（[1:T*fs2]-T*fs2/2）/fs2;
%?wav_ref?=?conj（exp（1i*2*pi*f1*t_ref+1i*pi*K*t_ref.^2））;

sigout?=?filter（wav_ref1sigout）;

figure（‘Name‘‘Match?filter?output‘）;
subplot（211）plot（abs（sigout））;
logsigout?=?20*log10（abs（sigout）/max（abs（sigout）））;
subplot（212）plot（logsigout）;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2020-09-10?11:07??FPGA實驗\matlab\
?????文件????????1837??2013-12-30?14:40??FPGA實驗\matlab\Sub_InterFreqQuadDemod.m
?????文件????????1469??2014-02-26?21:59??FPGA實驗\matlab\simu_system.m
?????文件??????835519??2018-05-31?18:46??FPGA實驗\基于線性調頻信號的脈沖壓縮處理.pdf
?????目錄???????????0??2020-09-10?11:07??FPGA實驗\