clcclose?allclear?all;
%%?parameters
f0??????=?24.125e9;?%%?center?freq?unit:?Hz
fm??????=?100;??????%%?unit:?Hz
tm??????=?1/fm;?????%%?unit:?s
N???????=?1024;?????%%?points?of?FFT?trans
B???????=?100e6;????%%?mod?bandwidth?unit:?Hz
C???????=?3e8;??????%%?speed?of?light?unit:?m/s
d_2p????=?0.014;????%%?distance?between?two?echo?antennas?unit:?m
fs??????=?256e3;????%%?AD?sample?rate?unit:?Hz
t???????=?0:1/fs:1;?%%?range?of?time?domin（?1?second?）

%%?window?function?type?length?of?window?is?the?same?as?FFT
win?????=?chebwin（N）;

%%?user?define
ang_simu????????=?2;????????????????????%%?angle?base?on?normal?line?unit:?°
ang_hd??????????=?ang_simu/360*2*pi;????%%?angle?base?on?normal?line?unit:?rad
diff_refr???????=?sin（ang_hd）*d_2p;?????%%?distance_diff?of?two?echos?unit:?m?
ang_hd_lamda????=?diff_refr*f0/C*2*pi;??%%?phase_diff?of?two?echos?unit;?rad

r???????????=?90;???????????????????????%%?distance?base?on?normal?point?unit:?m??????????????
tao1????????=?2*r/C?+?diff_refr/C;??????%%?delay?of?echo1?unit:?s
tao2????????=?2*r/C;????????????????????%%?delay?of?echo2?unit:?s

%%?signals?after?mix
s1_mix_i?=?cos（2*pi*（f0?-?B*0.5）*tao1?+?2*pi*B*tao1.*t/tm）;
s1_mix_q?=?sin（2*pi*（f0?-?B*0.5）*tao1?+?2*pi*B*tao1.*t/tm）;
s2_mix_i?=?cos（2*pi*（f0?-?B*0.5）*tao2?+?2*pi*B*tao2.*t/tm）;
s2_mix_q?=?sin（2*pi*（f0?