text: /* -*- c++ -*- */
  /*
   * Copyright 2015 Free Software Foundation, Inc.
   *
   * This file is part of GNU Radio
   *
   * GNU Radio 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 3, or (at your option)
   * any later version.
   *
   * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
   * the Free Software Foundation, Inc., 51 Franklin Street,
   * Boston, MA 02110-1301, USA.
   */
  
  
  #ifndef INCLUDED_FEC_POLAR_DECODER_SC_H
  #define INCLUDED_FEC_POLAR_DECODER_SC_H
  
  #include <gnuradio/fec/api.h>
  #include <gnuradio/fec/polar_decoder_common.h>
  
  
  namespace gr {
    namespace fec {
      namespace code {
  
        /*!
         * \brief Standard successive cancellation (SC) decoder for POLAR codes
         *
         * \details
         * It expects float input with bits mapped 1 --> 1, 0 --> -1
         * Or: f = 2.0 * bit - 1.0
         *
         */
        class FEC_API polar_decoder_sc : public polar_decoder_common
        {
        public:
  
          /*!
           * \param block_size codeword size. MUST be a power of 2.
           * \param num_info_bits represents the number of information
           *        bits in a block. Also called frame_size. <= block_size
           * \param frozen_bit_positions is an integer vector which
           *        defines the position of all frozen bits in a block.
           *        Its size MUST be equal to block_size - num_info_bits.
           *        Also it must be sorted and every position must only
           *        occur once.
           * \param frozen_bit_values holds an unpacked byte for every
           *        frozen bit position. It defines if a frozen bit is
           *        fixed to '0' or '1'. Defaults to all ZERO.
           */
          static generic_decoder::sptr make(int block_size, int num_info_bits,
                                            std::vector<int> frozen_bit_positions,
                                            std::vector<char> frozen_bit_values);
          ~polar_decoder_sc();
  
          // FECAPI
          void generic_work(void *in_buffer, void *out_buffer);
  
        private:
          polar_decoder_sc(int block_size, int num_info_bits,
                           std::vector<int> frozen_bit_positions,
                           std::vector<char> frozen_bit_values);
  
          float* d_llr_vec;
          unsigned char* d_u_hat_vec;
  
          unsigned char retrieve_bit_from_llr(float llr, const int pos);
          void sc_decode(float* llrs, unsigned char* u);
        };
  
      } // namespace code
    } // namespace fec
  } // namespace gr
  
  #endif /* INCLUDED_FEC_POLAR_DECODER_SC_H */
  