function genpoly = rs_genpoly(n,k,b)
% clc
% clear all
% m = 4;
% n = 15; % n = 2^m-1;% (Integer between 3 and 2m-1)
% k = 11; b = 12; 
a = gf(2,log2(n+1)); % Root of primitive polynomial
%% (X - A^b)(X - A^b+1)...(X - A^b+2t-1)
% Factors that form generator polynomial
f = [1 a^b];
for i=1:n-k-1 % 2*t-1
    ff = [1 a^(b+i)];
    % Generator polynomial, same as r above.
    f = conv(f, ff);
end
genpoly = f;
% genpoly = rsgenpoly(n,k,19,12) % ,19,12