music.m

对均匀直线阵、半波振子进行各种方向图综合,用music算法进行的DOA估计

clear;


Pd=1000;
Fd=1;
Fs=4*Fd;
R=0.5;
Delay=5;
No=1;
m=4;
x1=randint(Pd,1,m);
x2=randint(Pd,1,m);
x3=randint(Pd,1,m);
%y1=modmap(x1,Fd,Fs,'qask',m);
%y2=modmap(x2,Fd,Fs,'qask',m);
%y3=modmap(x3,Fd,Fs,'qask',m);
%[rcv_a1,ti]=rcosflt(y1,Fd,Fs,'fir/sqrt/Fs',R,Delay);
%[rcv_a2,ti]=rcosflt(y2,Fd,Fs,'fir/sqrt/Fs',R,Delay);
%[rcv_a3,ti]=rcosflt(y3,Fd,Fs,'fir/sqrt/Fs',R,Delay);
s1=dmodce(x1,Fd,Fs,'ask',m);
s2=dmodce(x2,Fd,Fs,'ask',m);
s3=dmodce(x3,Fd,Fs,'ask',m);
%s1=demodmap(rcv_a1,Fd,Fs,'qam',m);
%s2=demodmap(rcv_a2,Fd,Fs,'qam',m);
%s3=demodmap(rcv_a3,Fd,Fs,'qam',m);
%s1=amodce(rcv_a1,10,'qam');
%s2=amodce(rcv_a2,10,'qam');
%s3=amodce(rcv_a3,10,'qam');

 

i=sqrt(-1);
j=i;
M=8;
p=3;
angle1=30;
angle2=35;
angle3=141;
th=[angle1;angle2;angle3];
nn=1024;
SN1=10;SN2=10;SN3=5;%%%dB
sn=[SN1;SN2;SN3];
degrad=pi/180;


u=1:nn;
S=[s1(u).';s2(u).';s3(u).'];
nr=randn(M,nn);
ni=randn(M,nn);
U=nr+j*ni;
Ps=S*S.'/nn;
ps=diag(Ps);
refp=2*10.^(sn/10);
tmp=sqrt(refp./ps);
S2=diag(tmp)*S;

tmp=-i*pi*cos(th'*degrad);


tmp2=[0:M-1]';
a2=tmp2*tmp;
A=exp(a2);
X=A*S2+U;
Rxx=X*X'/nn;
[U,S,V]=svd(Rxx);%%%特征分解
Vs=U(:,1:p);
Vu=U(:,p+1:M);

th2=[0:180]';
tmp=-i*pi*cos(th2'*degrad);
tmp2=[0:M-1]';
a2=tmp2*tmp;
A2=exp(a2);
num=diag(A2'*A2);
Ena=Vu'*A2;
den=diag(Ena'*Ena);
doa=num./den;

semilogy(th2,doa);
title('MUSIC Spectrum');
xlabel('Angle(deg)');
ylabel('Spectrum');
axis([0 180 0.1 1e7]);
grid;