GNU Radio 3.7.1 C++ API
cma_equalizer_cc.h
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00001 /* -*- c++ -*- */
00002 /*
00003  * Copyright 2011,2012 Free Software Foundation, Inc.
00004  * 
00005  * This file is part of GNU Radio
00006  * 
00007  * GNU Radio is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 3, or (at your option)
00010  * any later version.
00011  * 
00012  * GNU Radio is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  * 
00017  * You should have received a copy of the GNU General Public License
00018  * along with GNU Radio; see the file COPYING.  If not, write to
00019  * the Free Software Foundation, Inc., 51 Franklin Street,
00020  * Boston, MA 02110-1301, USA.
00021  */
00022 
00023 #ifndef INCLUDED_DIGITAL_CMA_EQUALIZER_CC_H
00024 #define INCLUDED_DIGITAL_CMA_EQUALIZER_CC_H
00025 
00026 #include <gnuradio/digital/api.h>
00027 #include <gnuradio/sync_decimator.h>
00028 
00029 namespace gr {
00030   namespace digital {
00031 
00032     /*!
00033      * \brief Implements constant modulus adaptive filter on complex stream
00034      * \ingroup equalizers_blk
00035      *
00036      * \details
00037      * The error value and tap update equations (for p=2) can be found in:
00038      *
00039      * D. Godard, "Self-Recovering Equalization and Carrier Tracking
00040      * in Two-Dimensional Data Communication Systems," IEEE
00041      * Transactions on Communications, Vol. 28, No. 11, pp. 1867 -
00042      * 1875, 1980.
00043      */
00044     class DIGITAL_API cma_equalizer_cc: virtual public sync_decimator
00045     {
00046     protected:
00047       virtual gr_complex error(const gr_complex &out) = 0;
00048       virtual void update_tap(gr_complex &tap, const gr_complex &in) = 0;
00049   
00050     public:
00051       // gr::digital::cma_equalizer_cc::sptr
00052       typedef boost::shared_ptr<cma_equalizer_cc> sptr;
00053 
00054       /*!
00055        * Make a CMA Equalizer block
00056        *
00057        * \param num_taps Numer of taps in the equalizer (channel size)
00058        * \param modulus Modulus of the modulated signals
00059        * \param mu Gain of the update loop
00060        * \param sps Number of samples per symbol of the input signal
00061        */
00062       static sptr make(int num_taps, float modulus, float mu, int sps);
00063 
00064       virtual void set_taps(const std::vector<gr_complex> &taps) = 0;
00065       virtual std::vector<gr_complex> taps() const = 0;
00066       virtual float gain() const = 0;
00067       virtual void set_gain(float mu) = 0;
00068       virtual float modulus() const = 0;
00069       virtual void set_modulus(float mod) = 0;
00070     };
00071 
00072   } /* namespace digital */
00073 } /* namespace gr */
00074 
00075 #endif /* INCLUDED_DIGITAL_CMA_EQUALIZER_CC_H */