fft.m

用matlab写的FFT程序。简单易懂！

echo_36=echo_i36+i*echo_q36;   %回波复信号1

tran_36_cn=conj(tran_36);
return_36=conv(tran_36_cn,echo_36);
%********************************************************************第37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)))];
s37=10*cos(2*pi*fo*(n-36*T_frame)-pha+pha37);
signal_37=s11.*s37;
 
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_doppler37=10*cos(2*pi*(fo+fd)*(n-36*T_frame)-pha+pha37);
r37=s_doppler37.*echo_mobj;
s_echo137=awgn(r37,20);                      %加了白噪声的回波信号
s_echo_37=s_echo137+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i37=local_oscillator_i.*signal_37;           % I路解调
t_q37=local_oscillator_q.*signal_37;        % Q路解调

b=fir1(20,0.2);
tran_i37=filter(b,1,t_i37);
tran_q37=filter(b,1,t_q37);

tran_37=tran_i37+i*tran_q37;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i37=local_oscillator_i.*s_echo_37;           % I路解调
s_echo_q37=local_oscillator_q.*s_echo_37;        % Q路解调
echo_i37=filter(b,1,s_echo_i37);
echo_q37=filter(b,1,s_echo_q37);

echo_37=echo_i37+i*echo_q37;   %回波复信号1

tran_37_cn=conj(tran_37);
return_37=conv(tran_37_cn,echo_37);
%********************************************************************第38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)))];
s38=10*cos(2*pi*fo*(n-37*T_frame)-pha+pha38);
signal_38=s11.*s38;
 
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_doppler38=10*cos(2*pi*(fo+fd)*(n-37*T_frame)-pha+pha38);
r38=s_doppler38.*echo_mobj;
s_echo138=awgn(r38,20);                      %加了白噪声的回波信号
s_echo_38=s_echo138+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i38=local_oscillator_i.*signal_38;           % I路解调
t_q38=local_oscillator_q.*signal_38;        % Q路解调

b=fir1(20,0.2);
tran_i38=filter(b,1,t_i38);
tran_q38=filter(b,1,t_q38);

tran_38=tran_i38+i*tran_q38;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i38=local_oscillator_i.*s_echo_38;           % I路解调
s_echo_q38=local_oscillator_q.*s_echo_38;        % Q路解调
echo_i38=filter(b,1,s_echo_i38);
echo_q38=filter(b,1,s_echo_q38);

echo_38=echo_i38+i*echo_q38;   %回波复信号1

tran_38_cn=conj(tran_38);
return_38=conv(tran_38_cn,echo_38);
%********************************************************************第39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)))];
s39=10*cos(2*pi*fo*(n-38*T_frame)-pha+pha39);
signal_39=s11.*s39;
 
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_doppler39=10*cos(2*pi*(fo+fd)*(n-38*T_frame)-pha+pha39);
r39=s_doppler39.*echo_mobj;
s_echo139=awgn(r39,20);                      %加了白噪声的回波信号
s_echo_39=s_echo139+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i39=local_oscillator_i.*signal_39;           % I路解调
t_q39=local_oscillator_q.*signal_39;        % Q路解调

b=fir1(20,0.2);
tran_i39=filter(b,1,t_i39);
tran_q39=filter(b,1,t_q39);

tran_39=tran_i39+i*tran_q39;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i39=local_oscillator_i.*s_echo_39;           % I路解调
s_echo_q39=local_oscillator_q.*s_echo_39;        % Q路解调
echo_i39=filter(b,1,s_echo_i39);
echo_q39=filter(b,1,s_echo_q39);

echo_39=echo_i39+i*echo_q39;   %回波复信号1

tran_39_cn=conj(tran_39);
return_39=conv(tran_39_cn,echo_39);
%********************************************************************第40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)))];
s40=10*cos(2*pi*fo*(n-39*T_frame)-pha+pha40);
signal_40=s11.*s40;
 
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_doppler40=10*cos(2*pi*(fo+fd)*(n-39*T_frame)-pha+pha40);
r40=s_doppler40.*echo_mobj;
s_echo140=awgn(r40,20);                      %加了白噪声的回波信号
s_echo_40=s_echo140+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i40=local_oscillator_i.*signal_40;           % I路解调
t_q40=local_oscillator_q.*signal_40;        % Q路解调

b=fir1(20,0.2);
tran_i40=filter(b,1,t_i40);
tran_q40=filter(b,1,t_q40);

tran_40=tran_i40+i*tran_q40;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i40=local_oscillator_i.*s_echo_40;           % I路解调
s_echo_q40=local_oscillator_q.*s_echo_40;        % Q路解调
echo_i40=filter(b,1,s_echo_i40);
echo_q40=filter(b,1,s_echo_q40);

echo_40=echo_i40+i*echo_q40;   %回波复信号1

tran_40_cn=conj(tran_40);
return_40=conv(tran_40_cn,echo_40);
%********************************************************************第41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)))];
s41=10*cos(2*pi*fo*(n-40*T_frame)-pha+pha41);
signal_41=s11.*s41;
 
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_doppler41=10*cos(2*pi*(fo+fd)*(n-40*T_frame)-pha+pha41);
r41=s_doppler41.*echo_mobj;
s_echo141=awgn(r41,20);                      %加了白噪声的回波信号
s_echo_41=s_echo141+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i41=local_oscillator_i.*signal_41;           % I路解调
t_q41=local_oscillator_q.*signal_41;        % Q路解调

b=fir1(20,0.2);
tran_i41=filter(b,1,t_i41);
tran_q41=filter(b,1,t_q41);

tran_41=tran_i41+i*tran_q41;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i41=local_oscillator_i.*s_echo_41;           % I路解调
s_echo_q41=local_oscillator_q.*s_echo_41;        % Q路解调
echo_i41=filter(b,1,s_echo_i41);
echo_q41=filter(b,1,s_echo_q41);

echo_41=echo_i41+i*echo_q41;   %回波复信号1

tran_41_cn=conj(tran_41);
return_41=conv(tran_41_cn,echo_41);
%********************************************************************第42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)))];
s42=10*cos(2*pi*fo*(n-41*T_frame)-pha+pha42);
signal_42=s11.*s42;
 
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_doppler42=10*cos(2*pi*(fo+fd)*(n-41*T_frame)-pha+pha42);
r42=s_doppler42.*echo_mobj;
s_echo142=awgn(r42,20);                      %加了白噪声的回波信号
s_echo_42=s_echo142+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i42=local_oscillator_i.*signal_42;           % I路解调
t_q42=local_oscillator_q.*signal_42;        % Q路解调

b=fir1(20,0.2);
tran_i42=filter(b,1,t_i42);
tran_q42=filter(b,1,t_q42);

tran_42=tran_i42+i*tran_q42;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i42=local_oscillator_i.*s_echo_42;           % I路解调
s_echo_q42=local_oscillator_q.*s_echo_42;        % Q路解调
echo_i42=filter(b,1,s_echo_i42);
echo_q42=filter(b,1,s_echo_q42);

echo_42=echo_i42+i*echo_q42;   %回波复信号1

tran_42_cn=conj(tran_42);
return_42=conv(tran_42_cn,echo_42);
%********************************************************************第43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)))];
s43=10*cos(2*pi*fo*(n-42*T_frame)-pha+pha43);
signal_43=s11.*s43;
 
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_doppler43=10*cos(2*pi*(fo+fd)*(n-42*T_frame)-pha+pha43);
r43=s_doppler43.*echo_mobj;
s_echo143=awgn(r43,20);                      %加了白噪声的回波信号
s_echo_43=s_echo143+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i43=local_oscillator_i.*signal_43;           % I路解调
t_q43=local_oscillator_q.*signal_43;        % Q路解调

b=fir1(20,0.2);
tran_i43=filter(b,1,t_i43);
tran_q43=filter(b,1,t_q43);

tran_43=tran_i43+i*tran_q43;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i43=local_oscillator_i.*s_echo_43;           % I路解调
s_echo_q43=local_oscillator_q.*s_echo_43;        % Q路解调
echo_i43=filter(b,1,s_echo_i43);
echo_q43=filter(b,1,s_echo_q43);

echo_43=echo_i43+i*echo_q43;   %回波复信号1

tran_43_cn=conj(tran_43);
return_43=conv(tran_43_cn,echo_43);
%********************************************************************第44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)))];
s44=10*cos(2*pi*fo*(n-43*T_frame)-pha+pha44);
signal_44=s11.*s44;
 
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_doppler44=10*cos(2*pi*(fo+fd)*(n-43*T_frame)-pha+pha44);
r44=s_doppler44.*echo_mobj;
s_echo144=awgn(r44,20);                      %加了白噪声的回波信号
s_echo_44=s_echo144+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i44=local_oscillator_i.*signal_44;           % I路解调
t_q44=local_oscillator_q.*signal_44;        % Q路解调

b=fir1(20,0.2);
tran_i44=filter(b,1,t_i44);
tran_q44=filter(b,1,t_q44);

tran_44=tran_i44+i*tran_q44;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i44=local_oscillator_i.*s_echo_44;           % I路解调
s_echo_q44=local_oscillator_q.*s_echo_44;        % Q路解调
echo_i44=filter(b,1,s_echo_i44);
echo_q44=filter(b,1,s_echo_q44);

echo_44=echo_i44+i*echo_q44;   %回波复信号1

tran_44_cn=conj(tran_44);
return_44=conv(tran_44_cn,echo_44);
%********************************************************************第45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)))];
s45=10*cos(2*pi*fo*(n-44*T_frame)-pha+pha45);
signal_45=s11.*s45;
 
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_doppler45=10*cos(2*pi*(fo+fd)*(n-44*T_frame)-pha+pha45);
r45=s_doppler45.*echo_mobj;
s_echo145=awgn(r45,20);                      %加了白噪声的回波信号
s_echo_45=s_echo145+s_echo_clutter;
 
%%%%%%发射信号1正交解调 %%%%%%
t_i45=local_oscillator_i.*signal_45;           % I路解调
t_q45=local_oscillator_q.*signal_45;        % Q路解调

b=fir1(20,0.2);
tran_i45=filter(b,1,t_i45);
tran_q45=filter(b,1,t_q45);

tran_45=tran_i45+i*tran_q45;   %发射复信号1

%%%%%%%%%回波信号1正交解调%%%%%%%%%%%      

s_echo_i45=local_oscillator_i.*s_echo_45;           % I路解调
s_echo_q45=local_oscillator_q.*s_echo_45;        % Q路解调
echo_i45=filter(b,1,s_echo_i45);
echo_q45=filter(b,1,s_echo_q45);

echo_45=echo_i45+i*echo_q45;   %回波复信号1

tran_45_cn=conj(tran_45);
return_45=conv(tran_45_cn,echo_45);
%********************************************************************第46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)))];
s46=10*cos(2*pi*fo*(n-45*T_frame)-pha+pha46);
signal_46=s11.*s46;
 
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_doppler46=10*cos(2*pi*(fo+fd)*(n-45*T_frame)-pha+pha46);
r46=s_doppler46.*echo_mobj;
s_echo146=awgn(r46,20