close?all;??????????clear;
%%?產生Up_chirp和Down_chirp???????????????????%TB=16
Fs?=?200e6;??????????????????????????????????????????????????????????%采樣頻率是200MHz
Rb=?0.5e6;?%符號速率
t?=?（-1/（2*Rb）+1/Fs）?:?1/Fs?:?1/（2*Rb）?;??????????????????????%chirp寬度為2e-6秒
u?=?4e12?;?????????????????????????????????????????????????????????????%斜率u=4e12;
f_0?=?40e6?;??????????????????????????????????????????????????????????%中心頻率fo=40MHz
Up_chirp?=?cos（2*pi*（f_0*t+0.5*u*t.^2））;???????????????????%Up_chirp
Down_chirp?=?fliplr（Up_chirp）;
%%?Chirp?BOK調制
N=length（t）;
Symbol=10;??????????????????????????????????????????????????????????%仿真碼元個數
Bit_send?=?randi（[0?1]1Symbol）;

Signal_send?=?zeros（1Symbol*N）;
for?num=1:Symbol
????if?Bit_send（num）==1
????????Signal_send（（?num-1）*N?+?1:?num*N?）=Up_chirp;
????else
????????Signal_send（?（num-1）*N?+?1?:?num*N?）=Down_chirp;
????end;
end;
%%?解調
NUM_FFT=1024;
FFT_Up=fft（Up_chirpNUM_FFT）;
FFT_Down=fft（Down_chirpNUM_FFT）;
Up_match?=?zeros（1Symbol*NUM_FFT）;
Down_match?=?zeros（1Symbol*NUM_FFT）;
for?num=1:Symbol
????FFT_window=fft（Signal_send（（num-1）*N+1?:?num*N）NUM_FFT）;
????Up_match（（num-1）*NUM_FFT+1?:?num*NUM_FFT）=abs（ifft（FFT_window.*FFT_DownNUM_FFT））;
????Down_match（（num-1）*NUM_FFT+1?:?num*NUM_FFT）=abs（ifft（FFT_window.*FFT_UpNUM_FFT））;
end;

Bit_figure?=?kron（Bit_sendones（1NUM_FFT））;???????????%純屬為了好看

figure（1）;subplot（411）;plot（Bit_figure）;title（‘發送符號‘）;axis（[0?Symbol*NUM_FFT?-0.5?1.5]）?
?????????????subplot（412）;plot（Up_match）;title（‘符號“1”匹配輸出‘）;axis（[0?Symbol*NUM_FFT?0?max（Up_match）]）?
?????????????subplot（413）;plot（Down_match）;title（‘符號“0”匹配輸出‘）;axis（[0?Symbol*NUM_FFT?0?max（Up_match）]）?
?????????????subplot（414）;plot（Up_match-Down_match）;title（‘相減輸出‘）;axis（[0?Symbol*NUM_FFT?-max（Up_match）?max（Up_match）]）?

?????????????
?????????????
?????????????

?屬性????????????大小?????日期????時間???名稱
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?????文件????????1918??2011-06-23?11:19??Chirp_FDM.m