beamforming_music_bs1.m

含有波束空间MUSIC算法、阵元数变化的经典MUSIC算法统计分析、与平滑相关的矩阵分解MUSIC算法

%BEAMFORMING_MUSIC_BS1 ALOGRITHM
%DOA ESTIMATION BY BEAMFORMING_MUSIC(BS1)
clear all;
close all;
clc;

source_number=2;%信元数
sensor_number=8;%阵元数
B=4;%波束数
N_x=1024; %信号长度
snapshot_number=N_x;%快拍数
w=[pi/4 pi/6]';%信号频率
l=[(2*pi*3e8)/w(1) (2*pi*3e8)/w(2)];%信号波长  
d=[0.5*l(1) 0.5*l(2)];%阵元间距
snr=20;%信噪比

source_doa=[45 60];%两个信号的入射角度
A=[exp(-j*(0:sensor_number-1)*d(1)*2*pi*sin(source_doa(1)*pi/180)/l(1));exp(-j*(0:sensor_number-1)*d(2)*2*pi*sin(source_doa(2)*pi/180)/l(2))].';%阵列流型

s=10*exp(j*w*[0:N_x-1]);%仿真信号
%x=awgn(s,snr);
x=A*s+(1/sqrt(2))*(randn(sensor_number,N_x)+j*randn(sensor_number,N_x));%加了高斯白噪声后的阵列接收信号

%生成变换矩阵T
T=1/sqrt(sensor_number)*[exp(-j*(0:sensor_number-1)'*pi*sin(2/sensor_number)) exp(-j*(0:sensor_number-1)'*pi*sin(4/sensor_number)) exp(-j*(0:sensor_number-1)'*pi*sin(6/sensor_number)) exp(-j*(0:sensor_number-1)'*pi*sin(8/sensor_number))];                                             
T1=T'*T;
disp(T1);

%通过波束空间变换后的输出
y=T'*x;


R=y*y'/N_x;

%[V,D]=eig(R);
%Un=V(:,1:B-source_number);
%Gn=Un*Un';
[V,D]=eig(R);
D=diag(D);
disp(D);
Un=V(:,1:B-source_number);
Gn=Un*Un';

searching_doa=-90:0.1:90;%线阵的搜索范围为-90~90度
 for i=1:length(searching_doa)
   a_theta=exp(-j*(0:sensor_number-1)'*2*pi*d*sin(pi*searching_doa(i)/180)/l);
   Pmusic(i)=1./abs((a_theta)'*T*Gn*T'*a_theta);
 end
plot(searching_doa,10*log(Pmusic));
%axis([-90 90 -90 90]);
xlabel('入射角/度');
ylabel('谱峰');
legend('BEAMFORMING-MUSIC-BS1 Spectrum');
title('波束空间MUSIC估计');
grid on;