fft.m

用matlab写的FFT程序。简单易懂！

t_mobj=2*r/c;              % 动目标位置
echo_mobj=[zeros(1,t_mobj/ts),spt,zeros(1,(T_frame-t_mobj)/ts-length(spt))];
s_doppler27=10*cos(2*pi*(fo+fd)*(n-26*T_frame)-pha+pha27);
r27=s_doppler27.*echo_mobj;
s_echo127=awgn(r27,20);                      %加了白噪声的回波信号
s_echo_27=s_echo127+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i27=local_oscillator_i.*signal_27;           % I路解调
t_q27=local_oscillator_q.*signal_27;        % Q路解调

b=fir1(20,0.2);
tran_i27=filter(b,1,t_i27);
tran_q27=filter(b,1,t_q27);

tran_27=tran_i27+i*tran_q27;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i27=local_oscillator_i.*s_echo_27;           % I路解调
s_echo_q27=local_oscillator_q.*s_echo_27;        % Q路解调
echo_i27=filter(b,1,s_echo_i27);
echo_q27=filter(b,1,s_echo_q27);

echo_27=echo_i27+i*echo_q27;   %回波复信号1

tran_27_cn=conj(tran_27);
return_27=conv(tran_27_cn,echo_27);
%********************************************************************第28路*************************************************************************%
n1=0:ts:tao-ts;
spt=ones(1,length(n1)); 
n=0:ts:T_frame-ts;
s11=[spt, zeros(1,(T_frame/ts-length(spt)))];
s28=10*cos(2*pi*fo*(n-27*T_frame)-pha+pha28);
signal_28=s11.*s28;
 
n=0:ts:T_frame-ts;
t_mobj=2*r/c;              % 动目标位置
echo_mobj=[zeros(1,t_mobj/ts),spt,zeros(1,(T_frame-t_mobj)/ts-length(spt))];
s_doppler28=10*cos(2*pi*(fo+fd)*(n-27*T_frame)-pha+pha28);
r28=s_doppler28.*echo_mobj;
s_echo128=awgn(r28,20);                      %加了白噪声的回波信号
s_echo_28=s_echo128+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i28=local_oscillator_i.*signal_28;           % I路解调
t_q28=local_oscillator_q.*signal_28;        % Q路解调

b=fir1(20,0.2);
tran_i28=filter(b,1,t_i28);
tran_q28=filter(b,1,t_q28);

tran_28=tran_i28+i*tran_q28;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i28=local_oscillator_i.*s_echo_28;           % I路解调
s_echo_q28=local_oscillator_q.*s_echo_28;        % Q路解调
echo_i28=filter(b,1,s_echo_i28);
echo_q28=filter(b,1,s_echo_q28);

echo_28=echo_i28+i*echo_q28;   %回波复信号1

tran_28_cn=conj(tran_28);
return_28=conv(tran_28_cn,echo_28);
%********************************************************************第29路*************************************************************************%
n1=0:ts:tao-ts;
spt=ones(1,length(n1)); 
n=0:ts:T_frame-ts;
s11=[spt, zeros(1,(T_frame/ts-length(spt)))];
s29=10*cos(2*pi*fo*(n-28*T_frame)-pha+pha29);
signal_29=s11.*s29;
 
n=0:ts:T_frame-ts;
t_mobj=2*r/c;              % 动目标位置
echo_mobj=[zeros(1,t_mobj/ts),spt,zeros(1,(T_frame-t_mobj)/ts-length(spt))];
s_doppler29=10*cos(2*pi*(fo+fd)*(n-28*T_frame)-pha+pha29);
r29=s_doppler29.*echo_mobj;
s_echo129=awgn(r29,20);                      %加了白噪声的回波信号
s_echo_29=s_echo129+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i29=local_oscillator_i.*signal_29;           % I路解调
t_q29=local_oscillator_q.*signal_29;        % Q路解调

b=fir1(20,0.2);
tran_i29=filter(b,1,t_i29);
tran_q29=filter(b,1,t_q29);

tran_29=tran_i29+i*tran_q29;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i29=local_oscillator_i.*s_echo_29;           % I路解调
s_echo_q29=local_oscillator_q.*s_echo_29;        % Q路解调
echo_i29=filter(b,1,s_echo_i29);
echo_q29=filter(b,1,s_echo_q29);

echo_29=echo_i29+i*echo_q29;   %回波复信号1

tran_29_cn=conj(tran_29);
return_29=conv(tran_29_cn,echo_29);
%********************************************************************第30路*************************************************************************%
n1=0:ts:tao-ts;
spt=ones(1,length(n1)); 
n=0:ts:T_frame-ts;
s11=[spt, zeros(1,(T_frame/ts-length(spt)))];
s30=10*cos(2*pi*fo*(n-29*T_frame)-pha+pha30);
signal_30=s11.*s30;
 
n=0:ts:T_frame-ts;
t_mobj=2*r/c;              % 动目标位置
echo_mobj=[zeros(1,t_mobj/ts),spt,zeros(1,(T_frame-t_mobj)/ts-length(spt))];
s_doppler30=10*cos(2*pi*(fo+fd)*(n-29*T_frame)-pha+pha30);
r30=s_doppler30.*echo_mobj;
s_echo130=awgn(r30,20);                      %加了白噪声的回波信号
s_echo_30=s_echo130+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i30=local_oscillator_i.*signal_30;           % I路解调
t_q30=local_oscillator_q.*signal_30;        % Q路解调

b=fir1(20,0.2);
tran_i30=filter(b,1,t_i30);
tran_q30=filter(b,1,t_q30);

tran_30=tran_i30+i*tran_q30;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i30=local_oscillator_i.*s_echo_30;           % I路解调
s_echo_q30=local_oscillator_q.*s_echo_30;        % Q路解调
echo_i30=filter(b,1,s_echo_i30);
echo_q30=filter(b,1,s_echo_q30);

echo_30=echo_i30+i*echo_q30;   %回波复信号1

tran_30_cn=conj(tran_30);
return_30=conv(tran_30_cn,echo_30);
%********************************************************************第31路*************************************************************************%
n1=0:ts:tao-ts;
spt=ones(1,length(n1)); 
n=0:ts:T_frame-ts;
s11=[spt, zeros(1,(T_frame/ts-length(spt)))];
s31=10*cos(2*pi*fo*(n-30*T_frame)-pha+pha31);
signal_31=s11.*s31;
 
n=0:ts:T_frame-ts;
t_mobj=2*r/c;              % 动目标位置
echo_mobj=[zeros(1,t_mobj/ts),spt,zeros(1,(T_frame-t_mobj)/ts-length(spt))];
s_doppler31=10*cos(2*pi*(fo+fd)*(n-30*T_frame)-pha+pha31);
r31=s_doppler31.*echo_mobj;
s_echo131=awgn(r31,20);                      %加了白噪声的回波信号
s_echo_31=s_echo131+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i31=local_oscillator_i.*signal_31;           % I路解调
t_q31=local_oscillator_q.*signal_31;        % Q路解调

b=fir1(20,0.2);
tran_i31=filter(b,1,t_i31);
tran_q31=filter(b,1,t_q31);

tran_31=tran_i31+i*tran_q31;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i31=local_oscillator_i.*s_echo_31;           % I路解调
s_echo_q31=local_oscillator_q.*s_echo_31;        % Q路解调
echo_i31=filter(b,1,s_echo_i31);
echo_q31=filter(b,1,s_echo_q31);

echo_31=echo_i31+i*echo_q31;   %回波复信号1

tran_31_cn=conj(tran_31);
return_31=conv(tran_31_cn,echo_31);
%********************************************************************第32路*************************************************************************%
n1=0:ts:tao-ts;
spt=ones(1,length(n1)); 
n=0:ts:T_frame-ts;
s11=[spt, zeros(1,(T_frame/ts-length(spt)))];
s32=10*cos(2*pi*fo*(n-31*T_frame)-pha+pha32);
signal_32=s11.*s32;
 
n=0:ts:T_frame-ts;
t_mobj=2*r/c;              % 动目标位置
echo_mobj=[zeros(1,t_mobj/ts),spt,zeros(1,(T_frame-t_mobj)/ts-length(spt))];
s_doppler32=10*cos(2*pi*(fo+fd)*(n-31*T_frame)-pha+pha32);
r32=s_doppler32.*echo_mobj;
s_echo132=awgn(r32,20);                      %加了白噪声的回波信号
s_echo_32=s_echo132+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i32=local_oscillator_i.*signal_32;           % I路解调
t_q32=local_oscillator_q.*signal_32;        % Q路解调

b=fir1(20,0.2);
tran_i32=filter(b,1,t_i32);
tran_q32=filter(b,1,t_q32);

tran_32=tran_i32+i*tran_q32;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i32=local_oscillator_i.*s_echo_32;           % I路解调
s_echo_q32=local_oscillator_q.*s_echo_32;        % Q路解调
echo_i32=filter(b,1,s_echo_i32);
echo_q32=filter(b,1,s_echo_q32);

echo_32=echo_i32+i*echo_q32;   %回波复信号1

tran_32_cn=conj(tran_32);
return_32=conv(tran_32_cn,echo_32);
%********************************************************************第33路*************************************************************************%
n1=0:ts:tao-ts;
spt=ones(1,length(n1)); 
n=0:ts:T_frame-ts;
s11=[spt, zeros(1,(T_frame/ts-length(spt)))];
s33=10*cos(2*pi*fo*(n-32*T_frame)-pha+pha33);
signal_33=s11.*s33;
 
n=0:ts:T_frame-ts;
t_mobj=2*r/c;              % 动目标位置
echo_mobj=[zeros(1,t_mobj/ts),spt,zeros(1,(T_frame-t_mobj)/ts-length(spt))];
s_doppler33=10*cos(2*pi*(fo+fd)*(n-32*T_frame)-pha+pha33);
r33=s_doppler33.*echo_mobj;
s_echo133=awgn(r33,20);                      %加了白噪声的回波信号
s_echo_33=s_echo133+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i33=local_oscillator_i.*signal_33;           % I路解调
t_q33=local_oscillator_q.*signal_33;        % Q路解调

b=fir1(20,0.2);
tran_i33=filter(b,1,t_i33);
tran_q33=filter(b,1,t_q33);

tran_33=tran_i33+i*tran_q33;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i33=local_oscillator_i.*s_echo_33;           % I路解调
s_echo_q33=local_oscillator_q.*s_echo_33;        % Q路解调
echo_i33=filter(b,1,s_echo_i33);
echo_q33=filter(b,1,s_echo_q33);

echo_33=echo_i33+i*echo_q33;   %回波复信号1

tran_33_cn=conj(tran_33);
return_33=conv(tran_33_cn,echo_33);
%********************************************************************第34路*************************************************************************%
n1=0:ts:tao-ts;
spt=ones(1,length(n1)); 
n=0:ts:T_frame-ts;
s11=[spt, zeros(1,(T_frame/ts-length(spt)))];
s34=10*cos(2*pi*fo*(n-33*T_frame)-pha+pha34);
signal_34=s11.*s34;
 
n=0:ts:T_frame-ts;
t_mobj=2*r/c;              % 动目标位置
echo_mobj=[zeros(1,t_mobj/ts),spt,zeros(1,(T_frame-t_mobj)/ts-length(spt))];
s_doppler34=10*cos(2*pi*(fo+fd)*(n-33*T_frame)-pha+pha34);
r34=s_doppler34.*echo_mobj;
s_echo134=awgn(r34,20);                      %加了白噪声的回波信号
s_echo_34=s_echo134+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i34=local_oscillator_i.*signal_34;           % I路解调
t_q34=local_oscillator_q.*signal_34;        % Q路解调

b=fir1(20,0.2);
tran_i34=filter(b,1,t_i34);
tran_q34=filter(b,1,t_q34);

tran_34=tran_i34+i*tran_q34;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i34=local_oscillator_i.*s_echo_34;           % I路解调
s_echo_q34=local_oscillator_q.*s_echo_34;        % Q路解调
echo_i34=filter(b,1,s_echo_i34);
echo_q34=filter(b,1,s_echo_q34);

echo_34=echo_i34+i*echo_q34;   %回波复信号1

tran_34_cn=conj(tran_34);
return_34=conv(tran_34_cn,echo_34);
%********************************************************************第35路*************************************************************************%
n1=0:ts:tao-ts;
spt=ones(1,length(n1)); 
n=0:ts:T_frame-ts;
s11=[spt, zeros(1,(T_frame/ts-length(spt)))];
s35=10*cos(2*pi*fo*(n-34*T_frame)-pha+pha35);
signal_35=s11.*s35;
 
n=0:ts:T_frame-ts;
t_mobj=2*r/c;              % 动目标位置
echo_mobj=[zeros(1,t_mobj/ts),spt,zeros(1,(T_frame-t_mobj)/ts-length(spt))];
s_doppler35=10*cos(2*pi*(fo+fd)*(n-34*T_frame)-pha+pha35);
r35=s_doppler35.*echo_mobj;
s_echo135=awgn(r35,20);                      %加了白噪声的回波信号
s_echo_35=s_echo135+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i35=local_oscillator_i.*signal_35;           % I路解调
t_q35=local_oscillator_q.*signal_35;        % Q路解调

b=fir1(20,0.2);
tran_i35=filter(b,1,t_i35);
tran_q35=filter(b,1,t_q35);

tran_35=tran_i35+i*tran_q35;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i35=local_oscillator_i.*s_echo_35;           % I路解调
s_echo_q35=local_oscillator_q.*s_echo_35;        % Q路解调
echo_i35=filter(b,1,s_echo_i35);
echo_q35=filter(b,1,s_echo_q35);

echo_35=echo_i35+i*echo_q35;   %回波复信号1

tran_35_cn=conj(tran_35);
return_35=conv(tran_35_cn,echo_35);
%********************************************************************第36路*************************************************************************%
n1=0:ts:tao-ts;
spt=ones(1,length(n1)); 
n=0:ts:T_frame-ts;
s11=[spt, zeros(1,(T_frame/ts-length(spt)))];
s36=10*cos(2*pi*fo*(n-35*T_frame)-pha+pha36);
signal_36=s11.*s36;
 
n=0:ts:T_frame-ts;
t_mobj=2*r/c;              % 动目标位置
echo_mobj=[zeros(1,t_mobj/ts),spt,zeros(1,(T_frame-t_mobj)/ts-length(spt))];
s_doppler36=10*cos(2*pi*(fo+fd)*(n-35*T_frame)-pha+pha36);
r36=s_doppler36.*echo_mobj;
s_echo136=awgn(r36,20);                      %加了白噪声的回波信号
s_echo_36=s_echo136+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i36=local_oscillator_i.*signal_36;           % I路解调
t_q36=local_oscillator_q.*signal_36;        % Q路解调

b=fir1(20,0.2);
tran_i36=filter(b,1,t_i36);
tran_q36=filter(b,1,t_q36);

tran_36=tran_i36+i*tran_q36;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i36=local_oscillator_i.*s_echo_36;           % I路解调
s_echo_q36=local_oscillator_q.*s_echo_36;        % Q路解调
echo_i36=filter(b,1,s_echo_i36);
echo_q36=filter(b,1,s_echo_q36);