ofdm_cyclic_prefixer.h

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/* -*- c++ -*- */
/* 
 * Copyright 2013 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_DIGITAL_OFDM_CYCLIC_PREFIXER_H
#define INCLUDED_DIGITAL_OFDM_CYCLIC_PREFIXER_H

#include <gnuradio/digital/api.h>
#include <gnuradio/tagged_stream_block.h>

namespace gr {
  namespace digital {

    /*!
     * \brief Adds a cyclic prefix and performs pulse shaping on OFDM symbols.
     * \ingroup ofdm_blk
     *
     * \details
     * Input: OFDM symbols (in the time domain, i.e. after the IFFT). Optionally,
     *        entire frames can be processed. In this case, \p len_tag_key must be
     *        specified which holds the key of the tag that denotes how
     *        many OFDM symbols are in a frame.
     * Output: A stream of (scalar) complex symbols, which include the cyclic prefix
     *         and the pulse shaping.
     *         Note: If complete frames are processed, and \p rolloff_len is greater
     *         than zero, the final OFDM symbol is followed by the delay line of
     *         the pulse shaping.
     *
     * The pulse shape is a raised cosine in the time domain.
     */
    class DIGITAL_API ofdm_cyclic_prefixer : virtual public tagged_stream_block
    {
     public:
      typedef boost::shared_ptr<ofdm_cyclic_prefixer> sptr;

      /*!
       * \param input_size FFT length (i.e. length of the OFDM symbols)
       * \param output_size FFT length + cyclic prefix length (in samples)
       * \param rolloff_len Length of the rolloff flank in samples
       * \param len_tag_key For framed processing the key of the length tag
       */
      static sptr make(
          size_t input_size,
          size_t output_size,
          int rolloff_len=0,
          const std::string &len_tag_key=""
      );
    };

  } // namespace digital
} // namespace gr

#endif /* INCLUDED_DIGITAL_OFDM_CYCLIC_PREFIXER_H */