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Diffstat (limited to 'gr-digital/lib/digital_lms_dd_equalizer_cc.h')
-rw-r--r-- | gr-digital/lib/digital_lms_dd_equalizer_cc.h | 116 |
1 files changed, 0 insertions, 116 deletions
diff --git a/gr-digital/lib/digital_lms_dd_equalizer_cc.h b/gr-digital/lib/digital_lms_dd_equalizer_cc.h deleted file mode 100644 index e3ad4bf4a..000000000 --- a/gr-digital/lib/digital_lms_dd_equalizer_cc.h +++ /dev/null @@ -1,116 +0,0 @@ -/* -*- c++ -*- */ -/* - * Copyright 2011 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_LMS_DD_EQUALIZER_CC_H -#define INCLUDED_DIGITAL_LMS_DD_EQUALIZER_CC_H - -#include <gr_adaptive_fir_ccc.h> -#include <digital_constellation.h> - -class digital_lms_dd_equalizer_cc; -typedef boost::shared_ptr<digital_lms_dd_equalizer_cc> digital_lms_dd_equalizer_cc_sptr; - -digital_lms_dd_equalizer_cc_sptr digital_make_lms_dd_equalizer_cc (int num_taps, - float mu, int sps, - digital_constellation_sptr cnst); - -/*! - * \brief Least-Mean-Square Decision Directed Equalizer (complex in/out) - * \ingroup eq_blk - * - * This block implements an LMS-based decision-directed equalizer. - * It uses a set of weights, w, to correlate against the inputs, u, - * and a decisions is then made from this output. The error - * in the decision is used to update teh weight vector. - * - * y[n] = conj(w[n]) u[n] - * d[n] = decision(y[n]) - * e[n] = d[n] - y[n] - * w[n+1] = w[n] + mu u[n] conj(e[n]) - * - * Where mu is a gain value (between 0 and 1 and usualy small, - * around 0.001 - 0.01. - * - * This block uses the digital_constellation object for making - * the decision from y[n]. Create the constellation object for - * whatever constellation is to be used and pass in the object. - * In Python, you can use something like: - * self.constellation = digital.constellation_qpsk() - * To create a QPSK constellation (see the digital_constellation - * block for more details as to what constellations are available - * or how to create your own). You then pass the object to this - * block as an sptr, or using "self.constellation.base()". - * - * The theory for this algorithm can be found in Chapter 9 of: - * S. Haykin, Adaptive Filter Theory, Upper Saddle River, NJ: - * Prentice Hall, 1996. - * - */ -class digital_lms_dd_equalizer_cc : public gr_adaptive_fir_ccc -{ -private: - friend digital_lms_dd_equalizer_cc_sptr digital_make_lms_dd_equalizer_cc (int num_taps, - float mu, int sps, - digital_constellation_sptr cnst); - - float d_mu; - std::vector<gr_complex> d_taps; - digital_constellation_sptr d_cnst; - - digital_lms_dd_equalizer_cc (int num_taps, - float mu, int sps, - digital_constellation_sptr cnst); - -protected: - - virtual gr_complex error(const gr_complex &out) - { - gr_complex decision, error; - d_cnst->map_to_points(d_cnst->decision_maker(&out), &decision); - error = decision - out; - return error; - } - - virtual void update_tap(gr_complex &tap, const gr_complex &in) - { - tap += d_mu*conj(in)*d_error; - } - -public: - float get_gain() - { - return d_mu; - } - - void set_gain(float mu) - { - if(mu < 0.0f || mu > 1.0f) { - throw std::out_of_range("digital_lms_dd_equalizer::set_mu: Gain value must in [0, 1]"); - } - else { - d_mu = mu; - } - } - -}; - -#endif |