correlate_and_sync_cc.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_CORRELATE_AND_SYNC_CC_H
#define INCLUDED_DIGITAL_CORRELATE_AND_SYNC_CC_H

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

namespace gr {
namespace digital {

/*!
 * \brief Correlate to a preamble and send time/phase sync info
 * \ingroup deprecated_blk
 *
 * \details
 * Input:
 * \li Stream of complex samples.
 *
 * Output:
 * \li Output stream that just passes the input complex samples
 * \li tag 'phase_est': estimate of phase offset
 * \li tag 'timing_est': estimate of symbol timing offset
 * \li tag 'corr_est': the correlation value of the estimates
 *
 * This block is designed to search for a preamble by correlation
 * and uses the results of the correlation to get a time and phase
 * offset estimate. These estimates are passed downstream as
 * stream tags for use by follow-on synchronization blocks.
 *
 * The preamble is provided as a set of symbols along with a
 * baseband matched filter which we use to create the filtered and
 * upsampled symbol that we will receive over-the-air.
 *
 * The phase_est tag is used to adjust the phase estimation of any
 * downstream synchronization blocks and is currently used by the
 * gr::digital::costas_loop_cc block.
 *
 * The time_est tag is used to adjust the sampling timing
 * estimation of any downstream synchronization blocks and is
 * currently used by the gr::digital::pfb_clock_sync_ccf block.
 */
class DIGITAL_API correlate_and_sync_cc : virtual public sync_block
{
public:
    typedef boost::shared_ptr<correlate_and_sync_cc> sptr;

    /*!
     * Make a block that correlates against the \p symbols vector
     * and outputs a phase and symbol timing estimate.
     *
     * \param symbols Set of symbols to correlate against (e.g., a
     *                preamble).
     * \param filter  Baseband matched filter (e.g., RRC)
     * \param sps     Samples per symbol
     * \param nfilts  Number of filters in the internal PFB
     */
    static sptr make(const std::vector<gr_complex>& symbols,
                     const std::vector<float>& filter,
                     unsigned int sps,
                     unsigned int nfilts = 32);

    virtual std::vector<gr_complex> symbols() const = 0;
    virtual void set_symbols(const std::vector<gr_complex>& symbols) = 0;
};

} // namespace digital
} // namespace gr

#endif /* INCLUDED_DIGITAL_CORRELATE_AND_SYNC_CC_H */