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/* -*- c++ -*- */
/*
* Copyright 2011,2012 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_DIGITAL_CMA_EQUALIZER_CC_H
#define INCLUDED_DIGITAL_CMA_EQUALIZER_CC_H
#include <digital/api.h>
#include <gr_sync_decimator.h>
namespace gr {
namespace digital {
/*!
* \brief Implements constant modulus adaptive filter on complex stream
* \ingroup eq_blk
* \ingroup digital
*
* The error value and tap update equations (for p=2) can be found in:
*
* D. Godard, "Self-Recovering Equalization and Carrier Tracking
* in Two-Dimensional Data Communication Systems," IEEE
* Transactions on Communications, Vol. 28, No. 11, pp. 1867 -
* 1875, 1980.
*/
class DIGITAL_API cma_equalizer_cc: virtual public gr_sync_decimator
{
protected:
virtual gr_complex error(const gr_complex &out) = 0;
virtual void update_tap(gr_complex &tap, const gr_complex &in) = 0;
public:
// gr::digital::cma_equalizer_cc::sptr
typedef boost::shared_ptr<cma_equalizer_cc> sptr;
/*!
* Make a CMA Equalizer block
*
* \param num_taps Numer of taps in the equalizer (channel size)
* \param modulus Modulus of the modulated signals
* \param mu Gain of the update loop
* \param sps Number of samples per symbol of the input signal
*/
static sptr make(int num_taps, float modulus, float mu, int sps);
virtual void set_taps(const std::vector<gr_complex> &taps) = 0;
virtual std::vector<gr_complex> taps() const = 0;
virtual float gain() const = 0;
virtual void set_gain(float mu) = 0;
virtual float modulus() const = 0;
virtual void set_modulus(float mod) = 0;
};
} /* namespace digital */
} /* namespace gr */
#endif /* INCLUDED_DIGITAL_CMA_EQUALIZER_CC_H */
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