sa_ex8_4.m

这个是英文版<<Smart Antennas for Wireless Communications>>配套的matlab源程序

%Maximum Likelihood Array Weights
% example 8.4
d=.5;
N= 5;
sig2=.001;        % noise variance
theta=-pi/2:.01:pi/2;
ang=theta*180/pi;
th0=30*pi/180;      % receive angle

s=1;                %signal amplitude

a=[];
n1=[];
n2=[];
n=-(N-1)/2:(N-1)/2;
a=exp(1j*2*pi*n*d*sin(th0));  % array steering vector
a=a.';
Rnn=sig2*eye(N);        % noise correlation matrix       

w=inv(Rnn)*a./(a'*inv(Rnn)*a);           % calculated weight vector

for j=1:length(theta)
    th=theta(j);
    aa=[exp(1j*2*pi*n*d*sin(th))];  
    y(j)=w'*aa.';
end
figure;
plot(ang,abs(y)/max(abs(y)),'k')
axis([-90 90 0 1])
xlabel('\theta')
ylabel('|AF(\theta)|')
num2str(a,2)