ofdm_frame_equalizer_vcvc.h

Go to the documentation of this file.

/* -*- c++ -*- */
/* Copyright 2012 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_OFDM_FRAME_EQUALIZER_VCVC_H
#define INCLUDED_OFDM_FRAME_EQUALIZER_VCVC_H

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

namespace gr {
  namespace digital {

    /*!
     * \brief OFDM frame equalizer
     * \ingroup ofdm_blk
     *
     * \details
     * Performs equalization in one or two dimensions on a tagged OFDM frame.
     *
     * This does two things:
     * First, it removes the coarse carrier offset. If a tag is found on the first
     * item with the key 'ofdm_sync_carr_offset', this is interpreted as the coarse
     * frequency offset in number of carriers.
     * Next, it performs equalization in one or two dimensions on a tagged OFDM frame.
     * The actual equalization is done by a ofdm_frame_equalizer object, outside of
     * the block.
     *
     * Note that the tag with the coarse carrier offset is not removed. Blocks
     * downstream from this block must not attempt to also correct this offset.
     *
     * Input: a tagged series of OFDM symbols.
     * Output: The same as the input, but equalized and frequency-corrected.
     */
    class DIGITAL_API ofdm_frame_equalizer_vcvc : virtual public tagged_stream_block
    {
     public:
      typedef boost::shared_ptr<ofdm_frame_equalizer_vcvc> sptr;

      /*!
       * \param equalizer The equalizer object that will do the actual work
       * \param cp_len Length of the cyclic prefix in samples (required to correct the frequency offset)
       * \param tsb_key TSB key
       * \param propagate_channel_state If true, the channel state after the last symbol
       *                                will be added to the first symbol as a tag
       * \param fixed_frame_len Set if the frame length is fixed. When this value is given,
       *                        the TSB tag key can be left empty, but it is useful even
       *                        when using tagged streams at the input.
       */
      static sptr make(
          ofdm_equalizer_base::sptr equalizer,
          int cp_len,
          const std::string &tsb_key="frame_len",
          bool propagate_channel_state=false,
          int fixed_frame_len=0
      );
    };

  } // namespace digital
} // namespace gr

#endif /* INCLUDED_OFDM_FRAME_EQUALIZER_VCVC_H */