%Godara Method
% Example 8.1
d=.5;
N=3;

theta=-pi/2:.01:pi/2;
ang=theta*180/pi;
th0=0;      % receive angle
th1=-45*pi/180;          % first interferer angle
th2=60*pi/180;           % second interferer angle

n=0:(N-1);
a0=[exp(-1j*(2-n)*pi*sin(th0)) ]';   % received angle steering vector
a1=[exp(-1j*(2-n)*pi*sin(th1)) ]';   % interferer 1 steering vector
a2=[exp(-1j*(2-n)*pi*sin(th2)) ]';   % interferer 2 steering vector
A=[a0 a1 a2];

I=eye(length(A(:,1)));
u1=I(:,1);
w=u1'*inv(A);


for j=1:length(theta)
    th=theta(j);
    aa=[exp(-1j*(2-n)*pi*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)|')