music.m

经典MUSIC算法 进行DOA估计 出图效果良好

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;
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);
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;