function [g]=nrz(points)
%function [g]=nrz(points)
%points: sampling points in [0-T); must be even
%max(abs(conv(g,g)))=1

%Fulvio Babich, 2001

if rem(points,2)
   disp('error: points must be even');
   return;
end
g=ones(1,points)/points^.5;