music1.m

阵列信号处理_空间谱估计原理的一些基本算法——MusicEspritMp

  %  the  data of signal
clear;
format long;
c=3*10.^8;    % speed of light
L=8;          % the number of array
sam=128*2;      
N=128*2;
w1=1000;
w2=1001;
w3=1002;
w4=1003;
phase=0;
%Amp=10;
snr=20;
Amp=sqrt(2*10^(snr/10));
lamta=c/w1;
len=lamta/2;

P1=40*pi/360;
P2=60*pi/360;
P3=80*pi/360;
P4=120*pi/360;
%P;

for t=1:sam
    s1(t)=Amp*(exp(j*2*pi*w1*0.1*t));
    s2(t)=Amp*(exp(j*2*pi*w2*0.1*t));
    s3(t)=Amp*(exp(j*2*pi*w3*0.1*t));
    s4(t)=Amp*(exp(j*2*pi*w4*0.1*t));
end
  s=[s1(1:N);s2(1:N);s3(1:N);s4(1:N)];

  %n=1:1800;
  %aa=(0.1*n)*pi/180;
  
  i=1:L;
  x1=exp(j*2*pi*w1*(len*(i-1)*sin(P1))/c);
  x2=exp(j*2*pi*w2*(len*(i-1)*sin(P2))/c);
  x3=exp(j*2*pi*w3*(len*(i-1)*sin(P3))/c);
  x4=exp(j*2*pi*w4*(len*(i-1)*sin(P4))/c);
  a1=x1.';
  a2=x2.';
  a3=x3.';
  a4=x4.';
  a=[a1,a2,a3,a4];
  
  %a=[a1.';a2.'];
   
 noise=randn(L,N)+j*randn(L,N);
 
 z=a*s+noise;
 
 Rz=(z*z')/N;
 
 [e,v]=eig(Rz);

 es=e(:,5:L);
 en=e(:,(1:4));
itr=1800;  
aaaa=zeros(L,itr);
 for k=1:L;
     for h=1:itr;
         aaaa(k,h)=exp(j*pi*(k-1)*sin(0.1*h*pi/360));
         %aaaa(k,h)=exp(j*2*pi*w1*len*(k-1)*sin(0.1*h*pi/180)/c);
     end
 end
b=zeros(L);
for i=1:L;
 b(i,i)=1;
end
 c=b-es*es';
 for m=1:itr;
     aac=aaaa(:,m);
     pp=aac'*aac/((aac)'*c*aac); 
     %pp=1/((aac)'*c*aac);
     p(m)=real(pp);
    
 end
 %p1=p(1:4500);
 %p2=p(4501:9000);
%[m1,n1]=max(p1);
%doa1=n1/100
%[m2,n2]=max(p2);
%doa2=n2/100+45
u=0:0.1:180-0.1;
p=10*log(p);
plot(u,p);