u3_music.m

几种music算法

%MUSIC ALGORITHM
%DOA Estimation by ULA
clear all; 
close all;
clc


N_x=1024; 
N=8; 
l=1.8;
d=0.5*l;
M=3; 
w=[pi/6 pi/6 pi/6]';
xx=pi/6;yy=pi/6;zz=pi/6; %三个信号的入射角
B=[1 exp(-j*2*pi*d*sin(xx)/l) exp(-j*2*2*pi*d*sin(xx)/l) exp(-j*2*3*pi*d*sin(xx)/l) exp(-j*2*4*pi*d*sin(xx)/l) exp(-j*2*5*pi*d*sin(xx)/l) exp(-j*2*6*pi*d*sin(xx)/l) exp(-j*2*7*pi*d*sin(xx)/l);
   1 exp(-j*2*pi*d*sin(yy)/l) exp(-j*2*2*pi*d*sin(yy)/l) exp(-j*2*3*pi*d*sin(yy)/l) exp(-j*2*4*pi*d*sin(yy)/l) exp(-j*2*5*pi*d*sin(yy)/l) exp(-j*2*6*pi*d*sin(yy)/l) exp(-j*2*7*pi*d*sin(yy)/l);
   1 exp(-j*2*pi*d*sin(zz)/l) exp(-j*2*2*pi*d*sin(zz)/l) exp(-j*2*3*pi*d*sin(zz)/l) exp(-j*2*4*pi*d*sin(zz)/l) exp(-j*2*5*pi*d*sin(zz)/l) exp(-j*2*6*pi*d*sin(zz)/l) exp(-j*2*7*pi*d*sin(zz)/l)]'; 
xxx=2*exp(j*w*[0:N_x-1]);
x=B*xxx+randn(8,N_x)+j*randn(8,N_x);


R=x*x'/N_x;
[V D]=eig(R);
[lambda,index] = sort((diag(D)));
UU=V(:,index(1:5));
theta=-90:0.1:90;
for i = 1:length(theta)
    AA=[1 exp(-j*2*pi*d*sin(theta(i)/180*pi)/l) exp(-j*2*2*pi*d*sin(theta(i)/180*pi)/l) exp(-j*2*3*pi*d*sin(theta(i)/180*pi)/l) exp(-j*2*4*pi*d*sin(theta(i)/180*pi)/l) exp(-j*2*5*pi*d*sin(theta(i)/180*pi)/l) exp(-j*2*6*pi*d*sin(theta(i)/180*pi)/l) exp(-j*2*7*pi*d*sin(theta(i)/180*pi)/l)];%方向矢量
    WW=AA*UU*UU'*AA';
    Pmusic(i)=abs(1/WW);
end
Pmusic = 20*log10(Pmusic);
sita=-90:0.1:90;
plot(sita,Pmusic);
grid
xlabel('rad')