diff options
Diffstat (limited to 'gr-digital/lib')
| -rw-r--r-- | gr-digital/lib/.gitignore | 4 | ||||
| -rw-r--r-- | gr-digital/lib/Makefile.am | 51 | ||||
| -rw-r--r-- | gr-digital/lib/digital_cma_equalizer_cc.cc | 46 | ||||
| -rw-r--r-- | gr-digital/lib/digital_cma_equalizer_cc.h | 101 | ||||
| -rw-r--r-- | gr-digital/lib/digital_constellation.cc | 464 | ||||
| -rw-r--r-- | gr-digital/lib/digital_constellation.h | 352 | ||||
| -rw-r--r-- | gr-digital/lib/digital_constellation_decoder_cb.cc | 77 | ||||
| -rw-r--r-- | gr-digital/lib/digital_constellation_decoder_cb.h | 64 | ||||
| -rw-r--r-- | gr-digital/lib/digital_constellation_receiver_cb.cc | 131 | ||||
| -rw-r--r-- | gr-digital/lib/digital_constellation_receiver_cb.h | 149 | ||||
| -rw-r--r-- | gr-digital/lib/digital_costas_loop_cc.cc | 201 | ||||
| -rw-r--r-- | gr-digital/lib/digital_costas_loop_cc.h | 150 | ||||
| -rw-r--r-- | gr-digital/lib/digital_kurtotic_equalizer_cc.cc | 51 | ||||
| -rw-r--r-- | gr-digital/lib/digital_kurtotic_equalizer_cc.h | 111 | ||||
| -rw-r--r-- | gr-digital/lib/digital_lms_dd_equalizer_cc.cc | 85 | ||||
| -rw-r--r-- | gr-digital/lib/digital_lms_dd_equalizer_cc.h | 116 | ||||
| -rw-r--r-- | gr-digital/lib/digital_metric_type.h | 31 |
17 files changed, 2184 insertions, 0 deletions
diff --git a/gr-digital/lib/.gitignore b/gr-digital/lib/.gitignore new file mode 100644 index 000000000..1b6114c39 --- /dev/null +++ b/gr-digital/lib/.gitignore @@ -0,0 +1,4 @@ +/.libs +/.deps +/Makefile +/Makefile.in diff --git a/gr-digital/lib/Makefile.am b/gr-digital/lib/Makefile.am new file mode 100644 index 000000000..4f67614d8 --- /dev/null +++ b/gr-digital/lib/Makefile.am @@ -0,0 +1,51 @@ +# +# 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. +# + +include $(top_srcdir)/Makefile.common + +AM_CPPFLAGS = $(STD_DEFINES_AND_INCLUDES) $(PYTHON_CPPFLAGS) $(WITH_INCLUDES) + +# These headers get installed in ${prefix}/include/gnuradio +grinclude_HEADERS = \ + digital_constellation.h \ + digital_constellation_receiver_cb.h \ + digital_constellation_decoder_cb.h \ + digital_costas_loop_cc.h \ + digital_cma_equalizer_cc.h \ + digital_lms_dd_equalizer_cc.h \ + digital_kurtotic_equalizer_cc.h \ + digital_metric_type.h + +lib_LTLIBRARIES = libgnuradio-digital.la + +libgnuradio_digital_la_SOURCES = \ + digital_constellation.cc \ + digital_constellation_receiver_cb.cc \ + digital_constellation_decoder_cb.cc \ + digital_costas_loop_cc.cc \ + digital_cma_equalizer_cc.cc \ + digital_lms_dd_equalizer_cc.cc \ + digital_kurtotic_equalizer_cc.cc + +libgnuradio_digital_la_LIBADD = \ + $(GNURADIO_CORE_LA) + +libgnuradio_digital_la_LDFLAGS = $(NO_UNDEFINED) $(LTVERSIONFLAGS) diff --git a/gr-digital/lib/digital_cma_equalizer_cc.cc b/gr-digital/lib/digital_cma_equalizer_cc.cc new file mode 100644 index 000000000..c6c46c2d8 --- /dev/null +++ b/gr-digital/lib/digital_cma_equalizer_cc.cc @@ -0,0 +1,46 @@ +/* -*- 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. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <digital_cma_equalizer_cc.h> +#include <cstdio> + +digital_cma_equalizer_cc_sptr +digital_make_cma_equalizer_cc(int num_taps, float modulus, float mu, int sps) +{ + return gnuradio::get_initial_sptr(new digital_cma_equalizer_cc(num_taps, modulus, + mu, sps)); +} + +digital_cma_equalizer_cc::digital_cma_equalizer_cc(int num_taps, float modulus, + float mu, int sps) + : gr_adaptive_fir_ccc("cma_equalizer_cc", sps, + std::vector<gr_complex>(num_taps, gr_complex(0,0))) +{ + set_modulus(modulus); + set_gain(mu); + if (num_taps > 0) + d_taps[0] = 1.0; +} diff --git a/gr-digital/lib/digital_cma_equalizer_cc.h b/gr-digital/lib/digital_cma_equalizer_cc.h new file mode 100644 index 000000000..0dd99debd --- /dev/null +++ b/gr-digital/lib/digital_cma_equalizer_cc.h @@ -0,0 +1,101 @@ +/* -*- 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_CMA_EQUALIZER_CC_H +#define INCLUDED_DIGITAL_CMA_EQUALIZER_CC_H + +#include <gr_adaptive_fir_ccc.h> +#include <gr_math.h> +#include <iostream> + +class digital_cma_equalizer_cc; +typedef boost::shared_ptr<digital_cma_equalizer_cc> digital_cma_equalizer_cc_sptr; + +digital_cma_equalizer_cc_sptr +digital_make_cma_equalizer_cc(int num_taps, float modulus, float mu, int sps); + +/*! + * \brief Implements constant modulus adaptive filter on complex stream + * \ingroup eq_blk + * + * 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_cma_equalizer_cc : public gr_adaptive_fir_ccc +{ +private: + float d_modulus; + float d_mu; + + friend digital_cma_equalizer_cc_sptr digital_make_cma_equalizer_cc(int num_taps, + float modulus, + float mu, + int sps); + digital_cma_equalizer_cc(int num_taps, float modulus, float mu, int sps); + +protected: + + virtual gr_complex error(const gr_complex &out) + { + gr_complex error = out*(norm(out) - d_modulus); + float re = gr_clip(error.real(), 1.0); + float im = gr_clip(error.imag(), 1.0); + return gr_complex(re, im); + } + + virtual void update_tap(gr_complex &tap, const gr_complex &in) + { + // Hn+1 = Hn - mu*conj(Xn)*zn*(|zn|^2 - 1) + 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_cma_equalizer::set_gain: Gain value must be in [0,1]"); + } + d_mu = mu; + } + + float get_modulus() + { + return d_modulus; + } + + void set_modulus(float mod) + { + if(mod < 0) + throw std::out_of_range("digital_cma_equalizer::set_modulus: Modulus value must be >= 0"); + d_modulus = mod; + } +}; + +#endif diff --git a/gr-digital/lib/digital_constellation.cc b/gr-digital/lib/digital_constellation.cc new file mode 100644 index 000000000..2263bba0b --- /dev/null +++ b/gr-digital/lib/digital_constellation.cc @@ -0,0 +1,464 @@ +/* -*- c++ -*- */ +/* + * Copyright 2010, 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. + */ + +#include <gr_io_signature.h> +#include <digital_constellation.h> +#include <digital_metric_type.h> +#include <gr_math.h> +#include <gr_complex.h> +#include <math.h> +#include <iostream> +#include <stdlib.h> +#include <float.h> +#include <stdexcept> + +#define M_TWOPI (2*M_PI) +#define SQRT_TWO 0.707107 + +// Base Constellation Class + +digital_constellation::digital_constellation (std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, + unsigned int dimensionality) : + d_constellation(constellation), + d_pre_diff_code(pre_diff_code), + d_rotational_symmetry(rotational_symmetry), + d_dimensionality(dimensionality) +{ + if (pre_diff_code.size() == 0) + d_apply_pre_diff_code = false; + else if (pre_diff_code.size() != constellation.size()) + throw std::runtime_error ("The constellation and pre-diff code must be of the same length."); + else + d_apply_pre_diff_code = true; + calc_arity(); +} + +digital_constellation::digital_constellation () : + d_apply_pre_diff_code(false), + d_rotational_symmetry(0), + d_dimensionality(1) +{ + calc_arity(); +} + +//! Returns the constellation points for a symbol value +void +digital_constellation::map_to_points(unsigned int value, gr_complex *points) +{ + for (unsigned int i=0; i<d_dimensionality; i++) + points[i] = d_constellation[value*d_dimensionality + i]; +} + +std::vector<gr_complex> +digital_constellation::map_to_points_v(unsigned int value) +{ + std::vector<gr_complex> points_v; + points_v.resize(d_dimensionality); + map_to_points(value, &(points_v[0])); + return points_v; +} + +float +digital_constellation::get_distance(unsigned int index, const gr_complex *sample) +{ + float dist = 0; + for (unsigned int i=0; i<d_dimensionality; i++) { + dist += norm(sample[i] - d_constellation[index*d_dimensionality + i]); + } + return dist; +} + +unsigned int +digital_constellation::get_closest_point(const gr_complex *sample) +{ + unsigned int min_index = 0; + float min_euclid_dist; + float euclid_dist; + + min_euclid_dist = get_distance(0, sample); + min_index = 0; + for (unsigned int j = 1; j < d_arity; j++){ + euclid_dist = get_distance(j, sample); + if (euclid_dist < min_euclid_dist){ + min_euclid_dist = euclid_dist; + min_index = j; + } + } + return min_index; +} + +unsigned int +digital_constellation::decision_maker_pe(const gr_complex *sample, float *phase_error) +{ + unsigned int index = decision_maker(sample); + *phase_error = 0; + for (unsigned int d=0; d<d_dimensionality; d++) + *phase_error += -arg(sample[d]*conj(d_constellation[index+d])); + return index; +} + +/* +unsigned int digital_constellation::decision_maker_e(const gr_complex *sample, float *error) +{ + unsigned int index = decision_maker(sample); + *error = 0; + for (unsigned int d=0; d<d_dimensionality; d++) + *error += sample[d]*conj(d_constellation[index+d]); + return index; +} +*/ + +std::vector<gr_complex> digital_constellation::s_points () { + if (d_dimensionality != 1) + throw std::runtime_error ("s_points only works for dimensionality 1 constellations."); + else + return d_constellation; +} + +std::vector<std::vector<gr_complex> > +digital_constellation::v_points () +{ + std::vector<std::vector<gr_complex> > vv_const; + vv_const.resize(d_arity); + for (unsigned int p=0; p<d_arity; p++) { + std::vector<gr_complex> v_const; + v_const.resize(d_dimensionality); + for (unsigned int d=0; d<d_dimensionality; d++) { + v_const[d] = d_constellation[p*d_dimensionality+d]; + } + vv_const[p] = v_const; + } + return vv_const; +} + +void +digital_constellation::calc_metric(const gr_complex *sample, float *metric, + trellis_metric_type_t type) +{ + switch (type){ + case TRELLIS_EUCLIDEAN: + calc_euclidean_metric(sample, metric); + break; + case TRELLIS_HARD_SYMBOL: + calc_hard_symbol_metric(sample, metric); + break; + case TRELLIS_HARD_BIT: + throw std::runtime_error ("Invalid metric type (not yet implemented)."); + break; + default: + throw std::runtime_error ("Invalid metric type."); + } +} + +void +digital_constellation::calc_euclidean_metric(const gr_complex *sample, float *metric) +{ + for (unsigned int o=0; o<d_arity; o++) { + metric[o] = get_distance(o, sample); + } +} + +void +digital_constellation::calc_hard_symbol_metric(const gr_complex *sample, float *metric) +{ + float minm = FLT_MAX; + unsigned int minmi = 0; + for (unsigned int o=0; o<d_arity; o++) { + float dist = get_distance(o, sample); + if (dist < minm) { + minm = dist; + minmi = o; + } + } + for(unsigned int o=0; o<d_arity; o++) { + metric[o] = (o==minmi?0.0:1.0); + } +} + +void +digital_constellation::calc_arity () +{ + if (d_constellation.size() % d_dimensionality != 0) + throw std::runtime_error ("Constellation vector size must be a multiple of the dimensionality."); + d_arity = d_constellation.size()/d_dimensionality; +} + +unsigned int +digital_constellation::decision_maker_v (std::vector<gr_complex> sample) +{ + assert(sample.size() == d_dimensionality); + return decision_maker (&(sample[0])); +} + +digital_constellation_calcdist_sptr +digital_make_constellation_calcdist(std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, + unsigned int dimensionality) +{ + return digital_constellation_calcdist_sptr(new digital_constellation_calcdist + (constellation, pre_diff_code, + rotational_symmetry, dimensionality)); +} + +digital_constellation_calcdist::digital_constellation_calcdist(std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, + unsigned int dimensionality) : + digital_constellation(constellation, pre_diff_code, rotational_symmetry, dimensionality) +{} + +// Chooses points base on shortest distance. +// Inefficient. +unsigned int +digital_constellation_calcdist::decision_maker(const gr_complex *sample) +{ + return get_closest_point(sample); +} + +digital_constellation_sector::digital_constellation_sector (std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, + unsigned int dimensionality, + unsigned int n_sectors) : + digital_constellation(constellation, pre_diff_code, rotational_symmetry, dimensionality), + n_sectors(n_sectors) +{ +} + +unsigned int +digital_constellation_sector::decision_maker (const gr_complex *sample) +{ + unsigned int sector; + sector = get_sector(sample); + return sector_values[sector]; +} + +void +digital_constellation_sector::find_sector_values () +{ + unsigned int i; + sector_values.clear(); + for (i=0; i<n_sectors; i++) { + sector_values.push_back(calc_sector_value(i)); + } +} + +digital_constellation_rect_sptr +digital_make_constellation_rect(std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, + unsigned int real_sectors, unsigned int imag_sectors, + float width_real_sectors, float width_imag_sectors) +{ + return digital_constellation_rect_sptr(new digital_constellation_rect + (constellation, pre_diff_code, + rotational_symmetry, + real_sectors, imag_sectors, + width_real_sectors, + width_imag_sectors)); + } + +digital_constellation_rect::digital_constellation_rect (std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, + unsigned int real_sectors, unsigned int imag_sectors, + float width_real_sectors, float width_imag_sectors) : + digital_constellation_sector(constellation, pre_diff_code, rotational_symmetry, 1, real_sectors * imag_sectors), + n_real_sectors(real_sectors), n_imag_sectors(imag_sectors), + d_width_real_sectors(width_real_sectors), d_width_imag_sectors(width_imag_sectors) +{ + find_sector_values(); +} + +unsigned int +digital_constellation_rect::get_sector (const gr_complex *sample) +{ + int real_sector, imag_sector; + unsigned int sector; + + real_sector = int(real(*sample)/d_width_real_sectors + n_real_sectors/2.0); + if(real_sector < 0) + real_sector = 0; + if(real_sector >= (int)n_real_sectors) + real_sector = n_real_sectors-1; + + imag_sector = int(imag(*sample)/d_width_imag_sectors + n_imag_sectors/2.0); + if(imag_sector < 0) + imag_sector = 0; + if(imag_sector >= (int)n_imag_sectors) + imag_sector = n_imag_sectors-1; + + sector = real_sector * n_imag_sectors + imag_sector; + return sector; +} + +unsigned int +digital_constellation_rect::calc_sector_value (unsigned int sector) +{ + unsigned int real_sector, imag_sector; + gr_complex sector_center; + unsigned int closest_point; + real_sector = float(sector)/n_imag_sectors; + imag_sector = sector - real_sector * n_imag_sectors; + sector_center = gr_complex((real_sector + 0.5 - n_real_sectors/2.0) * d_width_real_sectors, + (imag_sector + 0.5 - n_imag_sectors/2.0) * d_width_imag_sectors); + closest_point = get_closest_point(§or_center); + return closest_point; +} + + +digital_constellation_psk_sptr +digital_make_constellation_psk(std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int n_sectors) +{ + return digital_constellation_psk_sptr(new digital_constellation_psk + (constellation, pre_diff_code, + n_sectors)); +} + +digital_constellation_psk::digital_constellation_psk (std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int n_sectors) : + digital_constellation_sector(constellation, pre_diff_code, constellation.size(), 1, n_sectors) +{ + find_sector_values(); +} + +unsigned int +digital_constellation_psk::get_sector (const gr_complex *sample) +{ + float phase = arg(*sample); + float width = M_TWOPI / n_sectors; + int sector = floor(phase/width + 0.5); + unsigned int u_sector; + if (sector < 0) + sector += n_sectors; + u_sector = sector; + return sector; +} + +unsigned int +digital_constellation_psk::calc_sector_value (unsigned int sector) +{ + float phase = sector * M_TWOPI / n_sectors; + gr_complex sector_center = gr_complex(cos(phase), sin(phase)); + unsigned int closest_point = get_closest_point(§or_center); + return closest_point; +} + + +digital_constellation_bpsk_sptr +digital_make_constellation_bpsk() +{ + return digital_constellation_bpsk_sptr(new digital_constellation_bpsk ()); +} + +digital_constellation_bpsk::digital_constellation_bpsk () +{ + d_constellation.resize(2); + d_constellation[0] = gr_complex(-1, 0); + d_constellation[1] = gr_complex(1, 0); + d_rotational_symmetry = 2; + d_dimensionality = 1; + calc_arity(); +} + +unsigned int +digital_constellation_bpsk::decision_maker(const gr_complex *sample) +{ + return (real(*sample) > 0); +} + + +digital_constellation_qpsk_sptr +digital_make_constellation_qpsk() +{ + return digital_constellation_qpsk_sptr(new digital_constellation_qpsk ()); +} + +digital_constellation_qpsk::digital_constellation_qpsk () +{ + d_constellation.resize(4); + // Gray-coded + d_constellation[0] = gr_complex(-SQRT_TWO, -SQRT_TWO); + d_constellation[1] = gr_complex(SQRT_TWO, -SQRT_TWO); + d_constellation[2] = gr_complex(-SQRT_TWO, SQRT_TWO); + d_constellation[3] = gr_complex(SQRT_TWO, SQRT_TWO); + d_rotational_symmetry = 4; + d_dimensionality = 1; + calc_arity(); +} + +unsigned int +digital_constellation_qpsk::decision_maker(const gr_complex *sample) +{ + // Real component determines small bit. + // Imag component determines big bit. + return 2*(imag(*sample)>0) + (real(*sample)>0); +} + + +digital_constellation_8psk_sptr +digital_make_constellation_8psk() +{ + return digital_constellation_8psk_sptr(new digital_constellation_8psk ()); +} + +digital_constellation_8psk::digital_constellation_8psk () +{ + float angle = M_PI/8.0; + d_constellation.resize(8); + // Gray-coded + d_constellation[0] = gr_complex(cos( 1*angle), sin( 1*angle)); + d_constellation[1] = gr_complex(cos( 7*angle), sin( 7*angle)); + d_constellation[2] = gr_complex(cos(15*angle), sin(15*angle)); + d_constellation[3] = gr_complex(cos( 9*angle), sin( 9*angle)); + d_constellation[4] = gr_complex(cos( 3*angle), sin( 3*angle)); + d_constellation[5] = gr_complex(cos( 5*angle), sin( 5*angle)); + d_constellation[6] = gr_complex(cos(13*angle), sin(13*angle)); + d_constellation[7] = gr_complex(cos(11*angle), sin(11*angle)); + d_rotational_symmetry = 8; + d_dimensionality = 1; + calc_arity(); +} + +unsigned int +digital_constellation_8psk::decision_maker(const gr_complex *sample) +{ + unsigned int ret = 0; + + float re = sample->real(); + float im = sample->imag(); + + if(fabsf(re) <= fabsf(im)) + ret = 4; + if(re <= 0) + ret |= 1; + if(im <= 0) + ret |= 2; + + return ret; +} diff --git a/gr-digital/lib/digital_constellation.h b/gr-digital/lib/digital_constellation.h new file mode 100644 index 000000000..4119b5803 --- /dev/null +++ b/gr-digital/lib/digital_constellation.h @@ -0,0 +1,352 @@ +/* -*- c++ -*- */ +/* + * Copyright 2010, 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_CONSTELLATION_H +#define INCLUDED_DIGITAL_CONSTELLATION_H + +#include <vector> +#include <math.h> +#include <gr_complex.h> +#include <boost/enable_shared_from_this.hpp> +#include <digital_metric_type.h> + +/************************************************************/ +/* digital_constellation */ +/* */ +/* Base class defining interface. */ +/************************************************************/ + +class digital_constellation; +typedef boost::shared_ptr<digital_constellation> digital_constellation_sptr; + +class digital_constellation : public boost::enable_shared_from_this<digital_constellation> +{ +public: + digital_constellation (std::vector<gr_complex> constellation, std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, unsigned int dimensionality); + digital_constellation (); + + //! Returns the constellation points for a symbol value + void map_to_points(unsigned int value, gr_complex *points); + std::vector<gr_complex> map_to_points_v(unsigned int value); + + //! Returns the constellation point that matches best. + virtual unsigned int decision_maker (const gr_complex *sample) = 0; + //! Takes a vector rather than a pointer. Better for SWIG wrapping. + unsigned int decision_maker_v (std::vector<gr_complex> sample); + //! Also calculates the phase error. + unsigned int decision_maker_pe (const gr_complex *sample, float *phase_error); + //! Calculates distance. + unsigned int decision_maker_e (const gr_complex *sample, float *error); + + //! Calculates metrics for all points in the constellation. + //! For use with the viterbi algorithm. + virtual void calc_metric(const gr_complex *sample, float *metric, trellis_metric_type_t type); + virtual void calc_euclidean_metric(const gr_complex *sample, float *metric); + virtual void calc_hard_symbol_metric(const gr_complex *sample, float *metric); + + //! Returns the set of points in this constellation. + std::vector<gr_complex> points() { return d_constellation;} + //! Returns the vector of points in this constellation. + //! Raise error if dimensionality is not one. + std::vector<gr_complex> s_points(); + //! Returns a vector of vectors of points. + std::vector<std::vector<gr_complex> > v_points(); + //! Whether to apply an encoding before doing differential encoding. (e.g. gray coding) + bool apply_pre_diff_code() { return d_apply_pre_diff_code;} + //! Returns the encoding to apply before differential encoding. + std::vector<unsigned int> pre_diff_code() { return d_pre_diff_code;} + //! Returns the order of rotational symmetry. + unsigned int rotational_symmetry() { return d_rotational_symmetry;} + //! Returns the number of complex numbers in a single symbol. + unsigned int dimensionality() {return d_dimensionality;} + + unsigned int bits_per_symbol () { + return floor(log(d_constellation.size())/d_dimensionality/log(2)); + } + + unsigned int arity () { + return d_arity; + } + + digital_constellation_sptr base() { + return shared_from_this(); + } + + protected: + + std::vector<gr_complex> d_constellation; + std::vector<unsigned int> d_pre_diff_code; + bool d_apply_pre_diff_code; + unsigned int d_rotational_symmetry; + unsigned int d_dimensionality; + unsigned int d_arity; + + float get_distance(unsigned int index, const gr_complex *sample); + unsigned int get_closest_point(const gr_complex *sample); + void calc_arity (); +}; + +/************************************************************/ +/* digital_constellation_calcdist */ +/* */ +/* Constellation which calculates the distance to each */ +/* point in the constellation for decision making. */ +/* Inefficient for large constellations. */ +/************************************************************/ + +class digital_constellation_calcdist; +typedef boost::shared_ptr<digital_constellation_calcdist> digital_constellation_calcdist_sptr; + +// public constructor +digital_constellation_calcdist_sptr +digital_make_constellation_calcdist (std::vector<gr_complex> constellation, std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, unsigned int dimensionality); + + +class digital_constellation_calcdist : public digital_constellation +{ + public: + digital_constellation_calcdist (std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, + unsigned int dimensionality); + unsigned int decision_maker (const gr_complex *sample); + // void calc_metric(gr_complex *sample, float *metric, trellis_metric_type_t type); + // void calc_euclidean_metric(gr_complex *sample, float *metric); + // void calc_hard_symbol_metric(gr_complex *sample, float *metric); + + private: + friend digital_constellation_calcdist_sptr + digital_make_constellation_calcdist (std::vector<gr_complex> constellation); +}; + +/************************************************************/ +/* digital_constellation_sector */ +/* */ +/* An abstract class. */ +/* Constellation space is divided into sectors. */ +/* Each sector is associated with the nearest constellation */ +/* point. */ +/************************************************************/ + +class digital_constellation_sector : public digital_constellation +{ + public: + + digital_constellation_sector (std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, + unsigned int dimensionality, + unsigned int n_sectors); + + unsigned int decision_maker (const gr_complex *sample); + + protected: + + virtual unsigned int get_sector (const gr_complex *sample) = 0; + virtual unsigned int calc_sector_value (unsigned int sector) = 0; + void find_sector_values (); + + unsigned int n_sectors; + + private: + + std::vector<unsigned int> sector_values; + +}; + +/************************************************************/ +/* digital_constellation_rect */ +/* */ +/* Only implemented for 1-(complex)dimensional */ +/* constellation. */ +/* Constellation space is divided into rectangular sectors. */ +/* Each sector is associated with the nearest constellation */ +/* point. */ +/* Works well for square QAM. */ +/* Works for any generic constellation provided sectors are */ +/* not too large. */ +/************************************************************/ + +class digital_constellation_rect; +typedef boost::shared_ptr<digital_constellation_rect> digital_constellation_rect_sptr; + +// public constructor +digital_constellation_rect_sptr +digital_make_constellation_rect (std::vector<gr_complex> constellation, std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, + unsigned int real_sectors, unsigned int imag_sectors, + float width_real_sectors, float width_imag_sectors); + +class digital_constellation_rect : public digital_constellation_sector +{ + public: + + digital_constellation_rect (std::vector<gr_complex> constellation, std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, + unsigned int real_sectors, unsigned int imag_sectors, + float width_real_sectors, float width_imag_sectors); + + protected: + + unsigned int get_sector (const gr_complex *sample); + + unsigned int calc_sector_value (unsigned int sector); + + private: + + unsigned int n_real_sectors; + unsigned int n_imag_sectors; + float d_width_real_sectors; + float d_width_imag_sectors; + + friend digital_constellation_rect_sptr + digital_make_constellation_rect (std::vector<gr_complex> constellation, std::vector<unsigned int> pre_diff_code, + unsigned int rotational_symmetry, + unsigned int real_sectors, unsigned int imag_sectors, + float width_real_sectors, float width_imag_sectors); + +}; + +/************************************************************/ +/* digital_constellation_psk */ +/* */ +/* Constellation space is divided into pie slices sectors. */ +/* Each slice is associated with the nearest constellation */ +/* point. */ +/* Works well for PSK but nothing else. */ +/* Assumes that there is a constellation point at 1. */ +/************************************************************/ + +class digital_constellation_psk; +typedef boost::shared_ptr<digital_constellation_psk> digital_constellation_psk_sptr; + +// public constructor +digital_constellation_psk_sptr +digital_make_constellation_psk (std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int n_sectors); + +class digital_constellation_psk : public digital_constellation_sector +{ + public: + + digital_constellation_psk (std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int n_sectors); + + protected: + + unsigned int get_sector (const gr_complex *sample); + + unsigned int calc_sector_value (unsigned int sector); + + private: + + friend digital_constellation_psk_sptr + digital_make_constellation_psk (std::vector<gr_complex> constellation, + std::vector<unsigned int> pre_diff_code, + unsigned int n_sectors); + +}; + +/************************************************************/ +/* digital_constellation_bpsk */ +/* */ +/* Only works for BPSK. */ +/* */ +/************************************************************/ + +class digital_constellation_bpsk; +typedef boost::shared_ptr<digital_constellation_bpsk> digital_constellation_bpsk_sptr; + +// public constructor +digital_constellation_bpsk_sptr +digital_make_constellation_bpsk (); + +class digital_constellation_bpsk : public digital_constellation +{ + public: + + digital_constellation_bpsk (); + unsigned int decision_maker (const gr_complex *sample); + + friend digital_constellation_bpsk_sptr + digital_make_constellation_bpsk (); + +}; + +/************************************************************/ +/* digital_constellation_qpsk */ +/* */ +/* Only works for QPSK. */ +/* */ +/************************************************************/ + +class digital_constellation_qpsk; +typedef boost::shared_ptr<digital_constellation_qpsk> digital_constellation_qpsk_sptr; + +// public constructor +digital_constellation_qpsk_sptr +digital_make_constellation_qpsk (); + +class digital_constellation_qpsk : public digital_constellation +{ + public: + + digital_constellation_qpsk (); + unsigned int decision_maker (const gr_complex *sample); + + friend digital_constellation_qpsk_sptr + digital_make_constellation_qpsk (); + +}; + + +/************************************************************/ +/* digital_constellation_8psk */ +/* */ +/* Only works for 8PSK. */ +/* */ +/************************************************************/ + +class digital_constellation_8psk; +typedef boost::shared_ptr<digital_constellation_8psk> digital_constellation_8psk_sptr; + +// public constructor +digital_constellation_8psk_sptr +digital_make_constellation_8psk (); + +class digital_constellation_8psk : public digital_constellation +{ + public: + + digital_constellation_8psk (); + unsigned int decision_maker (const gr_complex *sample); + + friend digital_constellation_8psk_sptr + digital_make_constellation_8psk (); + +}; + +#endif diff --git a/gr-digital/lib/digital_constellation_decoder_cb.cc b/gr-digital/lib/digital_constellation_decoder_cb.cc new file mode 100644 index 000000000..4638790f6 --- /dev/null +++ b/gr-digital/lib/digital_constellation_decoder_cb.cc @@ -0,0 +1,77 @@ +/* -*- 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. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <digital_constellation_decoder_cb.h> +#include <digital_constellation.h> +#include <gr_io_signature.h> +#include <iostream> + +digital_constellation_decoder_cb_sptr +digital_make_constellation_decoder_cb (digital_constellation_sptr constellation) +{ + return gnuradio::get_initial_sptr + (new digital_constellation_decoder_cb(constellation)); +} + +digital_constellation_decoder_cb:: +digital_constellation_decoder_cb (digital_constellation_sptr constellation) + : gr_block ("constellation_decoder_cb", + gr_make_io_signature (1, 1, sizeof (gr_complex)), + gr_make_io_signature (1, 1, sizeof (unsigned char))), + d_constellation(constellation), + d_dim(constellation->dimensionality()) +{ + set_relative_rate (1.0 / ((double) d_dim)); +} + +void +digital_constellation_decoder_cb::forecast (int noutput_items, + gr_vector_int &ninput_items_required) +{ + unsigned int input_required = noutput_items * d_dim; + + unsigned ninputs = ninput_items_required.size(); + for (unsigned int i = 0; i < ninputs; i++) + ninput_items_required[i] = input_required; +} + + +int +digital_constellation_decoder_cb::general_work (int noutput_items, + gr_vector_int &ninput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items) +{ + gr_complex const *in = (const gr_complex *) input_items[0]; + unsigned char *out = (unsigned char *) output_items[0]; + + for(int i = 0; i < noutput_items; i++){ + out[i] = d_constellation->decision_maker(&(in[i*d_dim])); + } + + consume_each (noutput_items * d_dim); + return noutput_items; +} diff --git a/gr-digital/lib/digital_constellation_decoder_cb.h b/gr-digital/lib/digital_constellation_decoder_cb.h new file mode 100644 index 000000000..022456733 --- /dev/null +++ b/gr-digital/lib/digital_constellation_decoder_cb.h @@ -0,0 +1,64 @@ +/* -*- 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_CONSTELLATION_DECODER_CB_H +#define INCLUDED_DIGITAL_CONSTELLATION_DECODER_CB_H + +#include <gr_block.h> +#include <digital_constellation.h> +#include <vector> + +class digital_constellation_decoder_cb; +typedef boost::shared_ptr<digital_constellation_decoder_cb>digital_constellation_decoder_cb_sptr; + +digital_constellation_decoder_cb_sptr +digital_make_constellation_decoder_cb (digital_constellation_sptr constellation); + +/*! + * \brief Constellation Decoder + * \ingroup coding_blk + * + */ +class digital_constellation_decoder_cb : public gr_block +{ + + private: + digital_constellation_sptr d_constellation; + unsigned int d_dim; + + friend digital_constellation_decoder_cb_sptr + digital_make_constellation_decoder_cb (digital_constellation_sptr constellation); + + digital_constellation_decoder_cb (digital_constellation_sptr constellation); + + public: + + 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 diff --git a/gr-digital/lib/digital_constellation_receiver_cb.cc b/gr-digital/lib/digital_constellation_receiver_cb.cc new file mode 100644 index 000000000..56385f11e --- /dev/null +++ b/gr-digital/lib/digital_constellation_receiver_cb.cc @@ -0,0 +1,131 @@ +/* -*- 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. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <gr_io_signature.h> +#include <gr_prefs.h> +#include <digital_constellation_receiver_cb.h> +#include <stdexcept> +#include <gr_math.h> +#include <gr_expj.h> + + +#define M_TWOPI (2*M_PI) +#define VERBOSE_MM 0 // Used for debugging symbol timing loop +#define VERBOSE_COSTAS 0 // Used for debugging phase and frequency tracking + +// Public constructor + +digital_constellation_receiver_cb_sptr +digital_make_constellation_receiver_cb(digital_constellation_sptr constell, + float alpha, float beta, + float fmin, float fmax) +{ + return gnuradio::get_initial_sptr(new digital_constellation_receiver_cb (constell, + alpha, beta, + fmin, fmax)); +} + +static int ios[] = {sizeof(char), sizeof(float), sizeof(float), sizeof(float)}; +static std::vector<int> iosig(ios, ios+sizeof(ios)/sizeof(int)); +digital_constellation_receiver_cb::digital_constellation_receiver_cb (digital_constellation_sptr constellation, + float alpha, float beta, + float fmin, float fmax) + : gr_block ("constellation_receiver_cb", + gr_make_io_signature (1, 1, sizeof (gr_complex)), + gr_make_io_signaturev (1, 4, iosig)), + d_constellation(constellation), + d_alpha(alpha), d_beta(beta), d_freq(0), d_max_freq(fmax), d_min_freq(fmin), d_phase(0), + d_current_const_point(0) +{ + if (d_constellation->dimensionality() != 1) + throw std::runtime_error ("This receiver only works with constellations of dimension 1."); +} + +void +digital_constellation_receiver_cb::phase_error_tracking(float phase_error) +{ + d_freq += d_beta*phase_error; // adjust frequency based on error + d_phase += d_freq + d_alpha*phase_error; // adjust phase based on error + + // Make sure we stay within +-2pi + while(d_phase > M_TWOPI) + d_phase -= M_TWOPI; + while(d_phase < -M_TWOPI) + d_phase += M_TWOPI; + + // Limit the frequency range + d_freq = gr_branchless_clip(d_freq, d_max_freq); + +#if VERBOSE_COSTAS + printf("cl: phase_error: %f phase: %f freq: %f sample: %f+j%f constellation: %f+j%f\n", + phase_error, d_phase, d_freq, sample.real(), sample.imag(), + d_constellation->points()[d_current_const_point].real(), + d_constellation->points()[d_current_const_point].imag()); +#endif +} + +int +digital_constellation_receiver_cb::general_work (int noutput_items, + gr_vector_int &ninput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items) +{ + const gr_complex *in = (const gr_complex *) input_items[0]; + unsigned char *out = (unsigned char *) output_items[0]; + + int i=0; + + float phase_error; + unsigned int sym_value; + gr_complex sample, nco; + + float *out_err = 0, *out_phase = 0, *out_freq = 0; + if(output_items.size() == 4) { + out_err = (float *) output_items[1]; + out_phase = (float *) output_items[2]; + out_freq = (float *) output_items[3]; + } + + while((i < noutput_items) && (i < ninput_items[0])) { + sample = in[i]; + nco = gr_expj(d_phase); // get the NCO value for derotating the current sample + sample = nco*sample; // get the downconverted symbol + sym_value = d_constellation->decision_maker_pe(&sample, &phase_error); + // phase_error = -arg(sample*conj(d_constellation->points()[sym_value])); + phase_error_tracking(phase_error); // corrects phase and frequency offsets + out[i] = sym_value; + if(output_items.size() == 4) { + out_err[i] = phase_error; + out_phase[i] = d_phase; + out_freq[i] = d_freq; + } + i++; + } + + consume_each(i); + return i; +} + diff --git a/gr-digital/lib/digital_constellation_receiver_cb.h b/gr-digital/lib/digital_constellation_receiver_cb.h new file mode 100644 index 000000000..bf6fc51fa --- /dev/null +++ b/gr-digital/lib/digital_constellation_receiver_cb.h @@ -0,0 +1,149 @@ +/* -*- 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_CONSTELLATION_RECEIVER_CB_H +#define INCLUDED_DIGITAL_CONSTELLATION_RECEIVER_CB_H + +#include <gr_block.h> +#include <digital_constellation.h> +#include <gr_complex.h> +#include <math.h> +#include <fstream> + +class digital_constellation_receiver_cb; +typedef boost::shared_ptr<digital_constellation_receiver_cb> digital_constellation_receiver_cb_sptr; + +// public constructor +digital_constellation_receiver_cb_sptr +digital_make_constellation_receiver_cb (digital_constellation_sptr constellation, + float alpha, float beta, + float fmin, float fmax); + +/*! + * \brief This block takes care of receiving generic modulated signals through phase, frequency, and symbol + * synchronization. + * \ingroup sync_blk + * \ingroup demod_blk + * + * This block takes care of receiving generic modulated signals through phase, frequency, and symbol + * synchronization. It performs carrier frequency and phase locking as well as symbol timing recovery. + * + * The phase and frequency synchronization are based on a Costas loop that finds the error of the incoming + * signal point compared to its nearest constellation point. The frequency and phase of the NCO are + * updated according to this error. + * + * The symbol synchronization is done using a modified Mueller and Muller circuit from the paper: + * + * G. R. Danesfahani, T.G. Jeans, "Optimisation of modified Mueller and Muller + * algorithm," Electronics Letters, Vol. 31, no. 13, 22 June 1995, pp. 1032 - 1033. + * + * This circuit interpolates the downconverted sample (using the NCO developed by the Costas loop) + * every mu samples, then it finds the sampling error based on this and the past symbols and the decision + * made on the samples. Like the phase error detector, there are optimized decision algorithms for BPSK + * and QPKS, but 8PSK uses another brute force computation against all possible symbols. The modifications + * to the M&M used here reduce self-noise. + * + */ + +class digital_constellation_receiver_cb : public gr_block +{ + public: + int general_work (int noutput_items, + gr_vector_int &ninput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items); + + + // Member function related to the phase/frequency tracking portion of the receiver + //! (CL) Returns the value for alpha (the phase gain term) + float alpha() const { return d_alpha; } + + //! (CL) Returns the value of beta (the frequency gain term) + float beta() const { return d_beta; } + + //! (CL) Returns the current value of the frequency of the NCO in the Costas loop + float freq() const { return d_freq; } + + //! (CL) Returns the current value of the phase of the NCO in the Costal loop + float phase() const { return d_phase; } + + //! (CL) Sets the value for alpha (the phase gain term) + void set_alpha(float alpha) { d_alpha = alpha; } + + //! (CL) Setss the value of beta (the frequency gain term) + void set_beta(float beta) { d_beta = beta; } + + //! (CL) Sets the current value of the frequency of the NCO in the Costas loop + void set_freq(float freq) { d_freq = freq; } + + //! (CL) Setss the current value of the phase of the NCO in the Costal loop + void set_phase(float phase) { d_phase = phase; } + + +protected: + + /*! + * \brief Constructor to synchronize incoming M-PSK symbols + * + * \param constellation constellation of points for generic modulation + * \param alpha gain parameter to adjust the phase in the Costas loop (~0.01) + * \param beta gain parameter to adjust the frequency in the Costas loop (~alpha^2/4) + * \param fmin minimum normalized frequency value the loop can achieve + * \param fmax maximum normalized frequency value the loop can achieve + * + * The constructor also chooses which phase detector and decision maker to use in the + * work loop based on the value of M. + */ + digital_constellation_receiver_cb (digital_constellation_sptr constellation, + float alpha, float beta, + float fmin, float fmax); + + void phase_error_tracking(float phase_error); + + private: + unsigned int d_M; + + // Members related to carrier and phase tracking + float d_alpha; + float d_beta; + float d_freq, d_max_freq, d_min_freq; + float d_phase; + + digital_constellation_sptr d_constellation; + unsigned int d_current_const_point; + + //! delay line length. + static const unsigned int DLLEN = 8; + + //! delay line plus some length for overflow protection + gr_complex d_dl[2*DLLEN] __attribute__ ((aligned(8))); + + //! index to delay line + unsigned int d_dl_idx; + + friend digital_constellation_receiver_cb_sptr + digital_make_constellation_receiver_cb (digital_constellation_sptr constell, + float alpha, float beta, + float fmin, float fmax); +}; + +#endif diff --git a/gr-digital/lib/digital_costas_loop_cc.cc b/gr-digital/lib/digital_costas_loop_cc.cc new file mode 100644 index 000000000..5d98bde4c --- /dev/null +++ b/gr-digital/lib/digital_costas_loop_cc.cc @@ -0,0 +1,201 @@ +/* -*- c++ -*- */ +/* + * Copyright 2006,2010,2011 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. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <digital_costas_loop_cc.h> +#include <gr_io_signature.h> +#include <gr_expj.h> +#include <gr_sincos.h> +#include <gr_math.h> + +#define M_TWOPI (2*M_PI) + +digital_costas_loop_cc_sptr +digital_make_costas_loop_cc (float damping, float nat_freq, + int order + ) throw (std::invalid_argument) +{ + return gnuradio::get_initial_sptr(new digital_costas_loop_cc (damping, + nat_freq, + order)); +} + +digital_costas_loop_cc::digital_costas_loop_cc (float damping, float nat_freq, + int order + ) throw (std::invalid_argument) + : gr_sync_block ("costas_loop_cc", + gr_make_io_signature (1, 1, sizeof (gr_complex)), + gr_make_io_signature2 (1, 2, sizeof (gr_complex), sizeof(float))), + d_max_freq(1.0), d_min_freq(-1.0), d_phase(0), d_freq(0.0), + d_nat_freq(nat_freq), d_damping(damping), + d_order(order), d_phase_detector(NULL) +{ + // initialize gains from the natural freq and damping factors + update_gains(); + + switch(d_order) { + case 2: + d_phase_detector = &digital_costas_loop_cc::phase_detector_2; + break; + + case 4: + d_phase_detector = &digital_costas_loop_cc::phase_detector_4; + break; + + case 8: + d_phase_detector = &digital_costas_loop_cc::phase_detector_8; + break; + + default: + throw std::invalid_argument("order must be 2, 4, or 8"); + break; + } +} + +float +digital_costas_loop_cc::phase_detector_8(gr_complex sample) const +{ + /* This technique splits the 8PSK constellation into 2 squashed + QPSK constellations, one when I is larger than Q and one where + Q is larger than I. The error is then calculated proportionally + to these squashed constellations by the const K = sqrt(2)-1. + + The signal magnitude must be > 1 or K will incorrectly bias + the error value. + + Ref: Z. Huang, Z. Yi, M. Zhang, K. Wang, "8PSK demodulation for + new generation DVB-S2", IEEE Proc. Int. Conf. Communications, + Circuits and Systems, Vol. 2, pp. 1447 - 1450, 2004. + */ + + float K = (sqrt(2.0) - 1); + if(fabsf(sample.real()) >= fabsf(sample.imag())) { + return ((sample.real()>0 ? 1.0 : -1.0) * sample.imag() - + (sample.imag()>0 ? 1.0 : -1.0) * sample.real() * K); + } + else { + return ((sample.real()>0 ? 1.0 : -1.0) * sample.imag() * K - + (sample.imag()>0 ? 1.0 : -1.0) * sample.real()); + } +} + +float +digital_costas_loop_cc::phase_detector_4(gr_complex sample) const +{ + + return ((sample.real()>0 ? 1.0 : -1.0) * sample.imag() - + (sample.imag()>0 ? 1.0 : -1.0) * sample.real()); +} + +float +digital_costas_loop_cc::phase_detector_2(gr_complex sample) const +{ + return (sample.real()*sample.imag()); +} + +void +digital_costas_loop_cc::set_natural_freq(float w) +{ + d_nat_freq = w; + update_gains(); +} + +void +digital_costas_loop_cc::set_damping_factor(float eta) +{ + d_damping = eta; + update_gains(); +} + +void +digital_costas_loop_cc::update_gains() +{ + d_beta = d_nat_freq*d_nat_freq; + d_alpha = 2*d_damping*d_nat_freq; +} + +int +digital_costas_loop_cc::work (int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items) +{ + const gr_complex *iptr = (gr_complex *) input_items[0]; + gr_complex *optr = (gr_complex *) output_items[0]; + float *foptr = (float *) output_items[1]; + + bool write_foptr = output_items.size() >= 2; + + float error; + gr_complex nco_out; + + if (write_foptr) { + + for (int i = 0; i < noutput_items; i++){ + nco_out = gr_expj(-d_phase); + optr[i] = iptr[i] * nco_out; + + error = (*this.*d_phase_detector)(optr[i]); + error = gr_branchless_clip(error, 1.0); + + d_freq = d_freq + d_beta * error; + d_phase = d_phase + d_freq + d_alpha * error; + + while(d_phase>M_TWOPI) + d_phase -= M_TWOPI; + while(d_phase<-M_TWOPI) + d_phase += M_TWOPI; + + if (d_freq > d_max_freq) + d_freq = d_min_freq; + else if (d_freq < d_min_freq) + d_freq = d_max_freq; + + foptr[i] = d_freq; + } + } else { + for (int i = 0; i < noutput_items; i++){ + nco_out = gr_expj(-d_phase); + optr[i] = iptr[i] * nco_out; + + error = (*this.*d_phase_detector)(optr[i]); + error = gr_branchless_clip(error, 1.0); + + d_freq = d_freq + d_beta * error; + d_phase = d_phase + d_freq + d_alpha * error; + + while(d_phase>M_TWOPI) + d_phase -= M_TWOPI; + while(d_phase<-M_TWOPI) + d_phase += M_TWOPI; + + if (d_freq > d_max_freq) + d_freq = d_min_freq; + else if (d_freq < d_min_freq) + d_freq = d_max_freq; + + } + } + return noutput_items; +} diff --git a/gr-digital/lib/digital_costas_loop_cc.h b/gr-digital/lib/digital_costas_loop_cc.h new file mode 100644 index 000000000..9c112d328 --- /dev/null +++ b/gr-digital/lib/digital_costas_loop_cc.h @@ -0,0 +1,150 @@ +/* -*- c++ -*- */ +/* + * Copyright 2006,2011 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_COSTAS_LOOP_CC_H +#define INCLUDED_DIGITAL_COSTAS_LOOP_CC_H + +#include <gr_sync_block.h> +#include <stdexcept> +#include <fstream> + + +/*! \brief A Costas loop carrier recovery module. + * \ingroup sync_blk + * + * The Costas loop locks to the center frequency of a signal and + * downconverts it to baseband. The second (order=2) order loop is + * used for BPSK where the real part of the output signal is the + * baseband BPSK signal and the imaginary part is the error + * signal. When order=4, it can be used for quadrature modulations + * where both I and Q (real and imaginary) are outputted. + * + * More details can be found online: + * + * J. Feigin, "Practical Costas loop design: Designing a simple and inexpensive + * BPSK Costas loop carrier recovery circuit," RF signal processing, pp. 20-36, + * 2002. + * + * http://rfdesign.com/images/archive/0102Feigin20.pdf + * + * \param alpha the loop gain used for phase adjustment + * \param beta the loop gain for frequency adjustments + * \param max_freq the maximum frequency deviation (radians/sample) the loop can handle + * \param min_freq the minimum frequency deviation (radians/sample) the loop can handle + * \param order the loop order, either 2 or 4 + */ +class digital_costas_loop_cc; +typedef boost::shared_ptr<digital_costas_loop_cc> digital_costas_loop_cc_sptr; + + +digital_costas_loop_cc_sptr +digital_make_costas_loop_cc (float damping, float nat_freq, + int order + ) throw (std::invalid_argument); + + +/*! + * \brief Carrier tracking PLL for QPSK + * \ingroup sync_blk + * input: complex; output: complex + * <br>The Costas loop can have two output streams: + * stream 1 is the baseband I and Q; + * stream 2 is the normalized frequency of the loop + * + * \p order must be 2 or 4. + */ +class digital_costas_loop_cc : public gr_sync_block +{ + friend digital_costas_loop_cc_sptr + digital_make_costas_loop_cc (float damping, float nat_freq, + int order + ) throw (std::invalid_argument); + + float d_alpha, d_beta, d_max_freq, d_min_freq, d_phase, d_freq; + float d_nat_freq, d_damping; + int d_order; + + digital_costas_loop_cc (float damping, float nat_freq, + int order + ) throw (std::invalid_argument); + + + /*! \brief update the system gains from omega and eta + * + * This function updates the system gains based on the natural + * frequency (omega) and damping factor (eta) of the system. + * These two factors can be set separately through their own + * set functions. + * + * These equations are summarized nicely in this paper from Berkeley: + * http://www.complextoreal.com/chapters/pll.pdf + */ + void update_gains(); + + /*! \brief the phase detector circuit for 8th-order PSK loops + * \param sample complex sample + * \return the phase error + */ + float phase_detector_8(gr_complex sample) const; // for 8PSK + + /*! \brief the phase detector circuit for fourth-order loops + * \param sample complex sample + * \return the phase error + */ + float phase_detector_4(gr_complex sample) const; // for QPSK + + /*! \brief the phase detector circuit for second-order loops + * \param sample a complex sample + * \return the phase error + */ + float phase_detector_2(gr_complex sample) const; // for BPSK + + + float (digital_costas_loop_cc::*d_phase_detector)(gr_complex sample) const; + +public: + + void set_natural_freq(float w); + void set_damping_factor(float eta); + + /*! \brief get the first order gain + * + */ + float alpha() const { return d_alpha; } + + /*! \brief get the second order gain + * + */ + float beta() const { return d_beta; } + + int work (int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items); + + /*! \brief returns the current NCO frequency in radians/sample + * + */ + float freq() const { return d_freq; } +}; + +#endif diff --git a/gr-digital/lib/digital_kurtotic_equalizer_cc.cc b/gr-digital/lib/digital_kurtotic_equalizer_cc.cc new file mode 100644 index 000000000..c95b56021 --- /dev/null +++ b/gr-digital/lib/digital_kurtotic_equalizer_cc.cc @@ -0,0 +1,51 @@ +/* -*- 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. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <digital_kurtotic_equalizer_cc.h> + +digital_kurtotic_equalizer_cc_sptr +digital_make_kurtotic_equalizer_cc(int num_taps, float mu) +{ + return gnuradio::get_initial_sptr(new digital_kurtotic_equalizer_cc(num_taps, mu)); +} + +digital_kurtotic_equalizer_cc::digital_kurtotic_equalizer_cc(int num_taps, float mu) + : gr_adaptive_fir_ccc("kurtotic_equalizer_cc", 1, std::vector<gr_complex>(num_taps)) +{ + set_gain(mu); + if (num_taps > 0) + d_taps[0] = 1.0; + + d_alpha_p = 0.01; + d_alpha_q = 0.01; + d_alpha_m = 0.01; + + d_p = 0.0f; + d_m = 0.0f; + d_q = gr_complex(0,0); + d_u = gr_complex(0,0); +} + diff --git a/gr-digital/lib/digital_kurtotic_equalizer_cc.h b/gr-digital/lib/digital_kurtotic_equalizer_cc.h new file mode 100644 index 000000000..e01cbd6e6 --- /dev/null +++ b/gr-digital/lib/digital_kurtotic_equalizer_cc.h @@ -0,0 +1,111 @@ +/* -*- 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_KURTOTIC_EQUALIZER_CC_H +#define INCLUDED_DIGITAL_KURTOTIC_EQUALIZER_CC_H + +#include <gr_adaptive_fir_ccc.h> +#include <gr_math.h> +#include <iostream> + +class digital_kurtotic_equalizer_cc; +typedef boost::shared_ptr<digital_kurtotic_equalizer_cc> digital_kurtotic_equalizer_cc_sptr; + +digital_kurtotic_equalizer_cc_sptr +digital_make_kurtotic_equalizer_cc(int num_taps, float mu); + +/*! + * \brief Implements a kurtosis-based adaptive equalizer on complex stream + * \ingroup eq_blk + * + * Y. Guo, J. Zhao, Y. Sun, "Sign kurtosis maximization based blind + * equalization algorithm," IEEE Conf. on Control, Automation, + * Robotics and Vision, Vol. 3, Dec. 2004, pp. 2052 - 2057. + */ +class digital_kurtotic_equalizer_cc : public gr_adaptive_fir_ccc +{ +private: + float d_mu; + float d_p, d_m; + gr_complex d_q, d_u; + float d_alpha_p, d_alpha_q, d_alpha_m; + + friend digital_kurtotic_equalizer_cc_sptr digital_make_kurtotic_equalizer_cc(int num_taps, + float mu); + digital_kurtotic_equalizer_cc(int num_taps, float mu); + + gr_complex sign(gr_complex x) + { + float re = (float)(x.real() >= 0.0f); + float im = (float)(x.imag() >= 0.0f); + return gr_complex(re, im); + } + +protected: + + virtual gr_complex error(const gr_complex &out) + { + + // p = E[|z|^2] + // q = E[z^2] + // m = E[|z|^4] + // u = E[kurtosis(z)] + + float nrm = norm(out); + gr_complex cnj = conj(out); + float epsilon_f = 1e-12; + gr_complex epsilon_c = gr_complex(1e-12, 1e-12); + + + d_p = (1-d_alpha_p)*d_p + (d_alpha_p)*nrm + epsilon_f; + d_q = (1-d_alpha_q)*d_q + (d_alpha_q)*out*out + epsilon_c; + d_m = (1-d_alpha_m)*d_m + (d_alpha_m)*nrm*nrm + epsilon_f; + d_u = d_m - 2.0f*(d_p*d_p) - d_q*d_q; + + gr_complex F = (1.0f / (d_p*d_p*d_p)) * + (sign(d_u) * (nrm*cnj - 2.0f*d_p*cnj - conj(d_q)*out) - + abs(d_u)*cnj); + + //std::cout << "out: " << out << " p: " << d_p << " q: " << d_q; + //std::cout << " m: " << d_m << " u: " << d_u << std::endl; + //std::cout << "error: " << F << std::endl; + + float re = gr_clip(F.real(), 1.0); + float im = gr_clip(F.imag(), 1.0); + return gr_complex(re, im); + } + + virtual void update_tap(gr_complex &tap, const gr_complex &in) + { + tap += d_mu*in*d_error; + } + +public: + void set_gain(float mu) + { + if(mu < 0) + throw std::out_of_range("digital_kurtotic_equalizer::set_gain: Gain value must be >= 0"); + d_mu = mu; + } +}; + +#endif diff --git a/gr-digital/lib/digital_lms_dd_equalizer_cc.cc b/gr-digital/lib/digital_lms_dd_equalizer_cc.cc new file mode 100644 index 000000000..e2c2f16f2 --- /dev/null +++ b/gr-digital/lib/digital_lms_dd_equalizer_cc.cc @@ -0,0 +1,85 @@ +/* -*- 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. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <digital_lms_dd_equalizer_cc.h> +#include <gr_io_signature.h> +#include <gr_misc.h> +#include <iostream> + +digital_lms_dd_equalizer_cc_sptr +digital_make_lms_dd_equalizer_cc(int num_taps, float mu, int sps, + digital_constellation_sptr cnst) +{ + return gnuradio::get_initial_sptr(new digital_lms_dd_equalizer_cc(num_taps, mu, + sps, cnst)); +} + +digital_lms_dd_equalizer_cc::digital_lms_dd_equalizer_cc(int num_taps, float mu, + int sps, + digital_constellation_sptr cnst) + : gr_adaptive_fir_ccc("lms_dd_equalizer_cc", sps, + std::vector<gr_complex>(num_taps, gr_complex(0,0))), + d_taps(num_taps), d_cnst(cnst) +{ + set_gain(mu); + if (num_taps > 0) + d_taps[num_taps/2] = 1.0; +} + + + + +/* +int +digital_lms_dd_equalizer_cc::work (int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items) +{ + const gr_complex *in = (const gr_complex *) input_items[0]; + gr_complex *out = (gr_complex *) output_items[0]; + + gr_complex acc, decision, error; + + for(int i = 0; i < noutput_items; i++) { + acc = 0; + + // Compute output + for (size_t j=0; j < d_taps.size(); j++) + acc += in[i+j] * conj(d_taps[j]); + + d_cnst->map_to_points(d_cnst->decision_maker(&acc), &decision); + error = decision - acc; + + // Update taps + for (size_t j=0; j < d_taps.size(); j++) + d_taps[j] += d_mu * conj(error) * in[i+j]; + + out[i] = acc; + } + + return noutput_items; +} +*/ diff --git a/gr-digital/lib/digital_lms_dd_equalizer_cc.h b/gr-digital/lib/digital_lms_dd_equalizer_cc.h new file mode 100644 index 000000000..e3ad4bf4a --- /dev/null +++ b/gr-digital/lib/digital_lms_dd_equalizer_cc.h @@ -0,0 +1,116 @@ +/* -*- 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 diff --git a/gr-digital/lib/digital_metric_type.h b/gr-digital/lib/digital_metric_type.h new file mode 100644 index 000000000..83de166f0 --- /dev/null +++ b/gr-digital/lib/digital_metric_type.h @@ -0,0 +1,31 @@ +/* -*- 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_DIGITAL_METRIC_TYPE_H +#define INCLUDED_DIGITAL_METRIC_TYPE_H + +typedef enum { + TRELLIS_EUCLIDEAN = 200, TRELLIS_HARD_SYMBOL, TRELLIS_HARD_BIT +} trellis_metric_type_t; + +#endif + |