hold off
subplot(2,2,1)
semilogy(G(:,1),G(:,2),'k:')
hold on
semilogy(G(:,1),G(:,3),'k-.')
semilogy(G(:,1),G(:,4),'k-')

d = 0.10741*(0.0662714/0.065207) * ones(size(G(:,1)));

semilogy(G(:,1),d,'k--');

% axis tight
xlabel 'Model \alpha'
ylabel 'BER'
title 'BER vs. Model \alpha'

axis([0 1 0.5e-1 0.5]);

a = axis;

x = a(1) + 1*(a(2)-a(1))/20;
y = a(3) + (a(4)-a(3))/3;

text(x,y, ['---- deterministic Model'; ...
           '....... Gaussian Model  '; ...
           '.-.-. Gauss-Markov Model'; ...
           '\_\_\_\_ known channel  ' ]);

hold off
