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/* -*- c++ -*- */
/*
* Copyright 2004 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_DAB_OFDM_SAMPLER_IMPL_H
#define INCLUDED_DAB_OFDM_SAMPLER_IMPL_H
#include <dab/ofdm_sampler.h>
namespace gr {
namespace dab {
/*!
* \brief cuts stream of DAB samples into symbol vectors
* \ingroup DAB
* \param fft_length length of the output vectors - number of samples per symbol without cyclic prefix
* \param cp_length lengith of the cyclic prefix
* \param symbols_per_frame number of symbols in a DAB frame, without Null symbol
* \param gap If the gap is > 0, leave a gap at the end of the symbol, i.e. return some of the cyclic prefix instead of the end of the symbol
*
* input: port 0: complex - actual data; port 1: byte stream with trigger signal indicating the start of a frame
* output: port 0: complex vectors - sampled data; port 1: byte stream with trigger signal indicating the start of a frame
*/
class ofdm_sampler_impl : public ofdm_sampler
{
private:
enum state_t {STATE_NS, STATE_CP, STATE_SYM};
state_t d_state;
unsigned int d_pos; // position inside OFDM symbol
unsigned int d_fft_length;
unsigned int d_cp_length;
unsigned int d_symbols_per_frame; // total number of symbols in a DAB frame
unsigned int d_sym_nr; // number of symbol inside DAB frame
unsigned int d_gap; // gap from next symbol -> if gap>0: sample before end of frame
unsigned int d_gap_left; // gap left to next symbol?
public:
ofdm_sampler_impl(unsigned int fft_length, unsigned int cp_length, unsigned int symbols_per_frame,unsigned int gap);
void forecast (int noutput_items, gr_vector_int &ninput_items_required);
int general_work (int noutput_items,
gr_vector_int &ninput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items);
};
}
}
#endif /* INCLUDED_DAB_OFDM_SAMPLER_H */
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