gen2par.m

数字通信第四版原书的例程

function h = gen2par(g);
%GEN2PAR Converts generator matrix to parity-check matrix in GF(2).
%       H = GEN2PAR(G) computes parity-check matrix H from generator matrix G.
%       The function can also used to convert parity-check matrix to generator
%       matrix. The conversion is used in GF(2) only.
%
%       See also: CYCLGEN, HAMMGEN.

%       Wes Wang 10/5/95
%       Copyright (c) 1995-96 by The MathWorks, Inc.
%       $Revision: 1.1 $  $Date: 1996/04/01 17:57:58 $

[n,m] = size(g);
if n >= m
    error('The input for GEN2PAR is not a generator or parity-check matrix')
end;

I = eye(n);
if abs(max(max(g(:, 1:n)-I))) == 0
    h = [g(:,n+1:m)' eye(m-n)];
elseif abs(max(max(g(:, m-n+1:m)-I))) == 0
    h = [eye(m-n) g(:,1:m-n)'];
else
    error('The input for GEN2PAR is not a generator or parity-check matrix')
end;

%--end of GEN2PAR