%FRFT
%50次統計平均

clc
clear?all
close?all
%常量設置
f0=2000;
B=500:200:2500;
fs=4*f0;

ts=0.5;
t=-1*ts/2:1/fs:ts/2;
alfa=pi/6;
alfa11=30;


t=-1*ts/2:1/fs:ts/2;
S=sqrt（ts/fs）;
dx=sqrt（ts*fs）;
tt=-1*dx/2:1/dx:dx/2;%歸一化之后的數據
point=ts*fs+1;


snr=5;

%濾波器
%?b=fir1（256[（f0-B/2）/（fs/2）（f0+B/2）/（fs/2）]）;
for?k=1:length（B）%k為snr;
????k
????for?k1=1:50%k1為統計平均次數
%造信號
????????signal=exp（i*2*pi*（f0）*tt*S+i*pi*（B（k）/ts）*tt.*tt*S*S）;
????????noise=normrnd（011point）;
????????nx=normrnd（011point）;
????????ny=normrnd（011point）;

????????%加信噪比
????????%信噪比db/Hz
????????b1=10^（snr/10）;??
????????a1=std（signal）;
????????a2=std（noise）;
????????n=sqrt（b1*a2*B（k）/a1/fs）;

????????signal1=n*signal;
????????p=signal1+noise;

????????%通過濾波器
%?????????p1=conv（bp）;?
%?????????p2=p1（129:1:point+128）;?

????????vx=signal1*cos（alfa）+nx;
%?????????vx1=conv（bvx）;
%?????????vx2=vx1（129:1:point+128）;

????????vy=signal1*sin（alfa）+ny;
%?????????vy1=conv（bvy）;
%?????????vy2=vy1（129:1:point+128）;
%時域
%?????????sypvy=mean（real（p.*conj（vy）））;
%?????????sypvx=mean（real（p.*conj（vx）））;
%?????????syalfa1（k1）=atan（sypvy/sypvx）*180/pi;
%頻域
????????p3=fft（p）;
????????vx3=fft（vx）;
????????vy3=fft（vy）;
????????
????????pvy=real（p3.*conj（vy3））;
????????pvx=real（p3.*conj（vx3））;
????????pvx1=mean（pvx（f0/2-B（k）/4:f0/2+B（k）/4））;
????????pvy1=mean（pvy（f0/2-B（k）/4:f0/2+B（k）/4））;
????????alfa1（k1）=atan（pvy1/pvx1）*180/pi;
??
?%分數階域????
????????a=atan（-1/（S*S*B（k）/ts））*2/pi+4;
????????frp3=frft（pa）;
????????frvx3=frft（vxa）;
????????frvy3=frft（vya）;
????????frpvy=real（frp3.*conj（frvy3））;
????????frpvx=real（frp3.*conj（frvx3））;
????????[CxIx]=max（frpvx）;
????????[CyIy]=max（frpvy）;
????????frpvy1=mean（frpvy（Iy-15:Iy+15））;
????????frpvx1=mean（frpvx（Ix-15:Ix+15））;
????????fralfa1（k1）=atan（frpvy1/frpvx1）*180/pi;?

????????
?
????????
????end
%?????頻域
????alfa2（k）=mean（alfa1）;
????error1=（alfa1-alfa2（k））;
????error2（k）=sqrt（mean（error1.^2））;
%?????時域;
%?????syalfa2（k）=mean（syalfa1）;
%?????syerror1=syalfa1-alfa11;
%?????syerror2（k）=sqrt（mean（syerror1.^2））;
%????分數階域
????fralfa2（k）=mean（fralfa1）;
????frerror1=fralfa1-alfa11;
????frerror2（k）=sqrt（mean（frerror1.^2））;
end


figure
plot（Berror2‘-*‘）;
hold?on?
%?plot（snrsyerror2‘-d‘）;
%?hold?on
plot（Bfrerror2‘-o‘）;

xlabel（‘輸入信噪比/（dB）‘）
ylabel（‘方位估計標準偏差/（°）‘）

figure
plot（Balfa2‘-*‘）%頻域
hold?on?
%?plot（snrsyalfa2‘-d‘）;%時域
%?hold?on?
plot（Bfralfa2‘-o‘）;%分數階域
xlabel（‘輸入信噪比/（dB）‘）
ylabel（‘估計方位/（°）‘）

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????2668??2010-10-26?11:01??BFRFT.m
?????文件????????2373??2010-06-19?09:37??chirpallfft.m
?????文件????????2237??2010-06-02?19:13??chirpcexiang.m
?????文件????????1182??2010-06-04?11:26??Chirpexample.m
?????文件????????2135??2010-07-03?12:33??chirpFrft.m
?????文件????????2527??2010-05-11?11:38??chirpFrfthuadongchuang.m
?????文件?????????973??2010-12-28?15:09??corror.m
?????文件????????1959??2010-05-20?20:59??CWcexiang.m
?????文件????????1560??2010-06-06?15:24??cWchirp.m
?????文件????????2130??2010-04-21?09:51??Disfrft.m
?????文件?????????141??2010-04-19?16:15??fconv.m
?????文件????????1620??2010-04-19?16:40??frft.m
?????文件?????????192??2010-04-19?16:21??interp.m
?????文件????????2727??2010-04-25?10:42??jiaoduguji.m
?????文件?????????310??2010-05-19?09:42??matlabalfa2.mat
?????文件?????????316??2010-05-19?09:41??matlaberror2.mat
?????文件????????2643??2010-07-03?22:09??PJSQQfft.m
?????文件????????1276??2011-01-05?16:57??pujisnr.m
?????文件?????????715??2010-04-23?09:22??RectExample.m
?????文件?????????977??2010-12-30?16:05??twodom.m