/*!
 * \file
 * \brief Definition of a BCH encoder/decoder class
 * \author Pal Frenger, Steve Peters and Adam Piatyszek
 *
 * -------------------------------------------------------------------------
 *
 * IT++ - C++ library of mathematical, signal processing, speech processing,
 *        and communications classes and functions
 *
 * Copyright (C) 1995-2009  (see AUTHORS file for a list of contributors)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * -------------------------------------------------------------------------
 */

#ifndef BCH_H
#define BCH_H

#include <itpp/comm/galois.h>
#include <itpp/comm/channel_code.h>


namespace itpp
{

/*!
  \addtogroup fec
*/

//---------------------- BCH --------------------------------------

/*!
  \ingroup fec
  \brief Class for binary, narrow-sense BCH codes.

  The notation used is found in S. B. Wicker, "Error control systems for
  digital communication and storage", Appendix E, Prentice-Hall, 1995.

  Example:
  \code BCH bch(31,21,2,"3 5 5 1")
  \endcode
  uses the generator polynomial
  \f$g(x) = x^{10} + x^9 + x^8 + x^6 + x^5 + x^3 + 1\f$, and is capable of
  correcting 2 errors with \a n = 31 and \a k = 21.
*/
class BCH : public Channel_Code
{
public:
  //! Initialize a (n,k)-code that can correct t errors
  BCH(int in_n, int in_k, int in_t, ivec genpolynom, bool sys = false);

  //! Destructor
  virtual ~BCH() { }

  //! Encode a bvec of indata
  virtual void encode(const bvec &uncoded_bits, bvec &coded_bits);
  //! Encode a bvec of indata
  virtual bvec encode(const bvec &uncoded_bits);

  //! Decode a bvec of coded data.
  virtual void decode(const bvec &coded_bits, bvec &decoded_bits);
  //! Decode a bvec of coded data
  virtual bvec decode(const bvec &coded_bits);

  // Soft-decision decoding is not implemented
  virtual void decode(const vec &received_signal, bvec &output);
  virtual bvec decode(const vec &received_signal);

  //! Get the code rate
  virtual double get_rate() const {return static_cast<double>(k) / n; }

  //! Dummy assignment operator - MSVC++ warning C4512
  BCH & operator=(const BCH &) { return *this; }
private:
  int n, k, t;
  GFX g;
  const bool systematic;
};

} // namespace itpp

#endif // #ifndef BCH_H
