LMS算法_RLS算法_波束形成_matlab_beamform_LMS_RLS

clear; close all; clc; s_n=3;%信元数 s_nn=16;%阵元数 N=1024; %信号长度 ww=[pi/4 pi/6 pi/8].';%信号频率 lamda=((2*pi*3e8)/ww(1)+(2*pi*3e8)/ww(3))/2;%信号波长 d=0.5*lamda;%阵元间距 snr=10;%信噪比 s_d=[0 -40 40];%信号的入射角度 delta0=5e-14;% N越大delta要求越小 v=0.98; Q=delta0*eye(s_nn); angle=-90:0.5:90; M=length(angle); a=zeros(s_nn,1); A=zeros(s_nn,s_n); w=zeros(s_nn,N); g=zeros(s_nn,N); u=[4e-3,zeros(1,N-1)]; yp=zeros(1,N); y=zeros(1,N); for n=1:s_n A(:,n)=[exp(-j*(0:s_nn-1)*d*2*pi*sin(s_d(n)*pi/180)/lamda)].'; end w(:,1)=A(:,1)/s_nn; s=sqrt(10.^(snr/10))*exp(j*ww*[0:N-1]);%仿真信号 x=A*s+(1/sqrt(2))*(randn(s_nn,N))+j*randn(s_nn,N);%加了高斯白噪声后的阵列接收信号 for n=2:N g(:,n)=(1/v*Q*x(:,n))/(1+1/v*x(:,n)'*Q*x(:,n)); Q=1/v*(Q-g(:,n)*x(:,n)'*Q); yp(n)=w(:,n-1)'*x(:,n); u(n)=inv(A(:,1)'*Q*A(:,1)); w(:,n)=(u(n)/(v*u(n-1)))*(w(:,n-1)-g(:,n)*yp(n)); end for k=1:M%画形成波束方向图 for m=1:s_nn a(m)=exp(-j*2*pi/lamda*d*(m-1)*sin(angle(k)*pi/180)); end beam_form(k)=w(:,n)'*a; end beam_form=abs(beam_form); beam_form=beam_form/max(beam_form);%归一化 beam_form=20*log10(beam_form); plot(angle,beam_form) xlabel('角度'); ylabel('方向图：dB'); title('形成波束方向图'); grid on