Lms_beamform.rar_LMS MATLAB_LMS自适应波束形成MATLAB程序_lms波束形成_波束形成

% LMS波束形成的MATLAB仿真程序 % Developed by xiaofei zhang (南京航空航天大学 电子工程系 张小飞） % EMAIL:zhangxiaofei@nuaa.edu.cn, fei_zxf@163.com clear all close all clc M=16; % the number of antenna K=2; % the number of sources theta=[0 30]; % DOA d=0.3; % antenna spacing N=500; % samples Meann=0; varn=1; % mean of noise,variance of noise SNR=20; % signal-to-noise ratio INR=20; % interference-to-noise ratio pp=zeros(100,N);pp1=zeros(100,N); rvar1=sqrt(varn) * 10^(SNR/20); % power of signal rvar2=sqrt(varn) * 10^(INR/20); % power of interference for q=1:100 s=[rvar1*exp(j*2*pi*(50*0.001*[0:N-1]));rvar2*exp(j*2*pi*(100*0.001*[0:N-1]+rand))]; % generate the source signals A=exp(-j*2*pi*d*[0:M-1].'*sin(theta*pi/180)); % the direction matrix e=sqrt(varn/2)*(randn(M,N)+j*randn(M,N)); % the noise Y=A*s+e; % the received data % LMS algorithm L=200 de =s(1, :); mu=0.0005; w = zeros(M, 1); for k = 1:N y(k) = w'*Y(:, k); % predict next sample and error e(k) = de(k) - y(k); % error w = w + mu * Y(:,k)*conj(e(k)); % adapt weight matrix and step size end end % beamforming using the LMS method beam=zeros(1,L); for i = 1 : L a=exp(-j*2*pi*d*[0:M-1].'*sin(-pi/2 + pi*(i-1)/L)); beam(i)=20*log10(abs(w'*a)); end % plotting figure angle=-90:180/200:(90-180/200); plot(angle,beam); grid on xlabel('方向角/degree'); ylabel('幅度响应/dB'); figure for k = 1:N en(k)=(abs(e(k))).^2; end semilogy(en); hold on xlabel('迭代次数'); ylabel('MSE');