2droot_music.txt

对二维矩形阵列

%----------------------------------------------
clc;
clear all;
tic;
close all;
% 模型的基本建立
% 对于来波信号的数目设置为NUM
NUM = 3;
% 天线阵列每行的阵元个数设置为M，共两行
M = 8;
% 波长间隔比d
dx = 0.5;
dy = 0.5;
% 采样点数
Sample_Num = 64;
t=[0:1:(Sample_Num-1)];

% 来波信号的设置，采用归一化频率的方法，频率分别设置为 0.2,0.4,0.6,初始相位均为0，功率初始为0dB
% 入射方位角为sita，高度角为phi
% 选择非相干的信号
f1 = 0.21;S1=sin(2*pi*f1*t);sita1=10;phi1=30;
f2 = 0.33;S2=sin(2*pi*f2*t);sita2=10;phi2=60;
f3 = 0.40;S3=sin(2*pi*f3*t);sita3=10;phi3=90;

sita = pi/180*[sita1,sita2,sita3];
phi = pi/180*[phi1,phi2,phi3];
% 形成信号矩阵 S＝3*Sample_Num
S=[S1;S2;S3];

% 构建阵元矩阵M×3
x_pos=[0:M-1,0:M-1].';
y_pos=[zeros(1,M),ones(1,M)].';
sensor_pos=[x_pos,y_pos];
for n=1:NUM
A(:,n)=exp(-j*pi*sensor_pos*[sin(sita(n))*cos(phi(n)),sin(sita(n))*sin(phi(n))].');
end
%构成阵元接收矩阵M×Sample_Num
X=A*S;

% 协方差矩阵RXX
RXX=X*X'/Sample_Num;

[V,D] = eig(RXX);
En=V(:,1:NUM);

rad=180/pi;
theta=[0:2:90];
phi =[0:2:180];
theta_counter=1;
for index_theta=theta
phi_counter=1;
for phi_index=phi
steering_vector=exp(-j*pi*sensor_pos*[sin(index_theta/rad)*cos(phi_index/rad),sin(index_theta/rad)*sin(phi_index/rad)].');
P_MUSIC(theta_counter,phi_counter)=1/abs(steering_vector'*En*En'*steering_vector);
phi_counter=phi_counter+1;
end
theta_counter=theta_counter+1;
end

figure(1);
mesh(phi,theta,10*log10(P_MUSIC));
xlabel('azimuth');
ylabel('elevation'); 

toc;