diff options
Diffstat (limited to 'gr-digital/lib')
31 files changed, 4361 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..34988d9a2 --- /dev/null +++ b/gr-digital/lib/Makefile.am @@ -0,0 +1,65 @@ +# +# 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_binary_slicer_fb.h \ + digital_clock_recovery_mm_cc.h \ + digital_clock_recovery_mm_ff.h \ + digital_constellation.h \ + digital_constellation_receiver_cb.h \ + digital_constellation_decoder_cb.h \ + digital_correlate_access_code_bb.h \ + digital_costas_loop_cc.h \ + digital_cma_equalizer_cc.h \ + digital_crc32.h \ + digital_fll_band_edge_cc.h \ + digital_lms_dd_equalizer_cc.h \ + digital_kurtotic_equalizer_cc.h \ + digital_metric_type.h \ + digital_mpsk_receiver_cc.h + +lib_LTLIBRARIES = libgnuradio-digital.la + +libgnuradio_digital_la_SOURCES = \ + digital_binary_slicer_fb.cc \ + digital_clock_recovery_mm_cc.cc \ + digital_clock_recovery_mm_ff.cc \ + digital_constellation.cc \ + digital_constellation_receiver_cb.cc \ + digital_constellation_decoder_cb.cc \ + digital_correlate_access_code_bb.cc \ + digital_costas_loop_cc.cc \ + digital_cma_equalizer_cc.cc \ + digital_crc32.cc \ + digital_fll_band_edge_cc.cc \ + digital_lms_dd_equalizer_cc.cc \ + digital_kurtotic_equalizer_cc.cc \ + digital_mpsk_receiver_cc.cc + +libgnuradio_digital_la_LIBADD = \ + $(GNURADIO_CORE_LA) + +libgnuradio_digital_la_LDFLAGS = $(NO_UNDEFINED) $(LTVERSIONFLAGS) diff --git a/gr-digital/lib/digital_binary_slicer_fb.cc b/gr-digital/lib/digital_binary_slicer_fb.cc new file mode 100644 index 000000000..fcdb4291f --- /dev/null +++ b/gr-digital/lib/digital_binary_slicer_fb.cc @@ -0,0 +1,59 @@ +/* -*- 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_binary_slicer_fb.h> +#include <gr_io_signature.h> +#include <gr_math.h> +#include <stdexcept> + +digital_binary_slicer_fb_sptr +digital_make_binary_slicer_fb () +{ + return gnuradio::get_initial_sptr(new digital_binary_slicer_fb ()); +} + +digital_binary_slicer_fb::digital_binary_slicer_fb () + : gr_sync_block ("binary_slicer_fb", + gr_make_io_signature (1, 1, sizeof (float)), + gr_make_io_signature (1, 1, sizeof (unsigned char))) +{ +} + +int +digital_binary_slicer_fb::work (int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items) +{ + const float *in = (const float *) input_items[0]; + unsigned char *out = (unsigned char *) output_items[0]; + + + for (int i = 0; i < noutput_items; i++){ + out[i] = gr_binary_slicer(in[i]); + } + + return noutput_items; +} diff --git a/gr-digital/lib/digital_binary_slicer_fb.h b/gr-digital/lib/digital_binary_slicer_fb.h new file mode 100644 index 000000000..2d10484db --- /dev/null +++ b/gr-digital/lib/digital_binary_slicer_fb.h @@ -0,0 +1,51 @@ +/* -*- 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_BINARY_SLICER_FB_H +#define INCLUDED_DIGITAL_BINARY_SLICER_FB_H + +#include <gr_sync_block.h> + +class digital_binary_slicer_fb; +typedef boost::shared_ptr<digital_binary_slicer_fb> digital_binary_slicer_fb_sptr; + +digital_binary_slicer_fb_sptr digital_make_binary_slicer_fb (); + +/*! + * \brief slice float binary symbol outputting 1 bit output + * \ingroup converter_blk + * + * x < 0 --> 0 + * x >= 0 --> 1 + */ +class digital_binary_slicer_fb : public gr_sync_block +{ + friend digital_binary_slicer_fb_sptr digital_make_binary_slicer_fb (); + digital_binary_slicer_fb (); + + public: + int work (int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items); +}; + +#endif diff --git a/gr-digital/lib/digital_clock_recovery_mm_cc.cc b/gr-digital/lib/digital_clock_recovery_mm_cc.cc new file mode 100644 index 000000000..198eb4b89 --- /dev/null +++ b/gr-digital/lib/digital_clock_recovery_mm_cc.cc @@ -0,0 +1,217 @@ +/* -*- c++ -*- */ +/* + * Copyright 2005,2006,2010,2011 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 <gr_io_signature.h> +#include <gr_prefs.h> +#include <digital_clock_recovery_mm_cc.h> +#include <gri_mmse_fir_interpolator_cc.h> +#include <stdexcept> +#include <cstdio> + + +// Public constructor +static const int FUDGE = 16; + +digital_clock_recovery_mm_cc_sptr +digital_make_clock_recovery_mm_cc(float omega, float gain_omega, + float mu, float gain_mu, + float omega_relative_limit) +{ + return gnuradio::get_initial_sptr(new digital_clock_recovery_mm_cc (omega, + gain_omega, + mu, + gain_mu, + omega_relative_limit)); +} + +digital_clock_recovery_mm_cc::digital_clock_recovery_mm_cc (float omega, float gain_omega, + float mu, float gain_mu, + float omega_relative_limit) + : gr_block ("clock_recovery_mm_cc", + gr_make_io_signature (1, 1, sizeof (gr_complex)), + gr_make_io_signature2 (1, 2, sizeof (gr_complex), sizeof(float))), + d_mu (mu), d_omega(omega), d_gain_omega(gain_omega), + d_omega_relative_limit(omega_relative_limit), + d_gain_mu(gain_mu), d_last_sample(0), d_interp(new gri_mmse_fir_interpolator_cc()), + d_verbose(gr_prefs::singleton()->get_bool("clock_recovery_mm_cc", "verbose", false)), + d_p_2T(0), d_p_1T(0), d_p_0T(0), d_c_2T(0), d_c_1T(0), d_c_0T(0) +{ + if (omega <= 0.0) + throw std::out_of_range ("clock rate must be > 0"); + if (gain_mu < 0 || gain_omega < 0) + throw std::out_of_range ("Gains must be non-negative"); + + set_omega(omega); // also sets min and max omega + set_relative_rate (1.0 / omega); + set_history(3); // ensure 2 extra input sample is available +} + +digital_clock_recovery_mm_cc::~digital_clock_recovery_mm_cc () +{ + delete d_interp; +} + +void +digital_clock_recovery_mm_cc::forecast(int noutput_items, gr_vector_int &ninput_items_required) +{ + unsigned ninputs = ninput_items_required.size(); + for (unsigned i=0; i < ninputs; i++) + ninput_items_required[i] = + (int) ceil((noutput_items * d_omega) + d_interp->ntaps()) + FUDGE; +} + +gr_complex +digital_clock_recovery_mm_cc::slicer_0deg (gr_complex sample) +{ + float real=0, imag=0; + + if(sample.real() > 0) + real = 1; + if(sample.imag() > 0) + imag = 1; + return gr_complex(real,imag); +} + +gr_complex +digital_clock_recovery_mm_cc::slicer_45deg (gr_complex sample) +{ + float real= -1, imag = -1; + if(sample.real() > 0) + real=1; + if(sample.imag() > 0) + imag = 1; + return gr_complex(real,imag); +} + +/* + Modified Mueller and Muller clock recovery circuit + Based: + 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. +*/ + +int +digital_clock_recovery_mm_cc::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]; + gr_complex *out = (gr_complex *) output_items[0]; + float *foptr = (float *) output_items[1]; + + bool write_foptr = output_items.size() >= 2; + + int ii = 0; // input index + int oo = 0; // output index + int ni = ninput_items[0] - d_interp->ntaps() - FUDGE; // don't use more input than this + + assert(d_mu >= 0.0); + assert(d_mu <= 1.0); + + float mm_val=0; + gr_complex u, x, y; + + // This loop writes the error to the second output, if it exists + if (write_foptr) { + while(oo < noutput_items && ii < ni) { + d_p_2T = d_p_1T; + d_p_1T = d_p_0T; + d_p_0T = d_interp->interpolate (&in[ii], d_mu); + + d_c_2T = d_c_1T; + d_c_1T = d_c_0T; + d_c_0T = slicer_0deg(d_p_0T); + + x = (d_c_0T - d_c_2T) * conj(d_p_1T); + y = (d_p_0T - d_p_2T) * conj(d_c_1T); + u = y - x; + mm_val = u.real(); + out[oo++] = d_p_0T; + + // limit mm_val + mm_val = gr_branchless_clip(mm_val,4.0); + d_omega = d_omega + d_gain_omega * mm_val; + d_omega = d_omega_mid + gr_branchless_clip(d_omega-d_omega_mid, d_omega_relative_limit); // make sure we don't walk away + + d_mu = d_mu + d_omega + d_gain_mu * mm_val; + ii += (int)floor(d_mu); + d_mu -= floor(d_mu); + + // write the error signal to the second output + foptr[oo-1] = mm_val; + + if (ii < 0) // clamp it. This should only happen with bogus input + ii = 0; + } + } + // This loop does not write to the second output (ugly, but faster) + else { + while(oo < noutput_items && ii < ni) { + d_p_2T = d_p_1T; + d_p_1T = d_p_0T; + d_p_0T = d_interp->interpolate (&in[ii], d_mu); + + d_c_2T = d_c_1T; + d_c_1T = d_c_0T; + d_c_0T = slicer_0deg(d_p_0T); + + x = (d_c_0T - d_c_2T) * conj(d_p_1T); + y = (d_p_0T - d_p_2T) * conj(d_c_1T); + u = y - x; + mm_val = u.real(); + out[oo++] = d_p_0T; + + // limit mm_val + mm_val = gr_branchless_clip(mm_val,1.0); + + d_omega = d_omega + d_gain_omega * mm_val; + d_omega = d_omega_mid + gr_branchless_clip(d_omega-d_omega_mid, d_omega_relative_limit); // make sure we don't walk away + + d_mu = d_mu + d_omega + d_gain_mu * mm_val; + ii += (int)floor(d_mu); + d_mu -= floor(d_mu); + + if(d_verbose) { + printf("%f\t%f\n", d_omega, d_mu); + } + + if (ii < 0) // clamp it. This should only happen with bogus input + ii = 0; + } + } + + if (ii > 0){ + if (ii > ninput_items[0]){ + fprintf(stderr, "gr_clock_recovery_mm_cc: ii > ninput_items[0] (%d > %d)\n", + ii, ninput_items[0]); + assert(0); + } + consume_each (ii); + } + + return oo; +} diff --git a/gr-digital/lib/digital_clock_recovery_mm_cc.h b/gr-digital/lib/digital_clock_recovery_mm_cc.h new file mode 100644 index 000000000..422bf811c --- /dev/null +++ b/gr-digital/lib/digital_clock_recovery_mm_cc.h @@ -0,0 +1,112 @@ +/* -*- c++ -*- */ +/* + * Copyright 2004,2011 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_CLOCK_RECOVERY_MM_CC_H +#define INCLUDED_DIGITAL_CLOCK_RECOVERY_MM_CC_H + +#include <gr_block.h> +#include <gr_complex.h> +#include <gr_math.h> + +class gri_mmse_fir_interpolator_cc; + +class digital_clock_recovery_mm_cc; +typedef boost::shared_ptr<digital_clock_recovery_mm_cc> digital_clock_recovery_mm_cc_sptr; + +// public constructor +digital_clock_recovery_mm_cc_sptr +digital_make_clock_recovery_mm_cc (float omega, float gain_omega, + float mu, float gain_mu, + float omega_relative_limit=0.001); + +/*! + * \brief Mueller and Müller (M&M) based clock recovery block with complex input, complex output. + * \ingroup sync_blk + * + * This implements the Mueller and Müller (M&M) discrete-time error-tracking synchronizer. + * The complex version here is based on: + * Modified Mueller and Muller clock recovery circuit + * Based: + * 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. + */ +class digital_clock_recovery_mm_cc : public gr_block +{ + public: + ~digital_clock_recovery_mm_cc (); + 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); + float mu() const { return d_mu;} + float omega() const { return d_omega;} + float gain_mu() const { return d_gain_mu;} + float gain_omega() const { return d_gain_omega;} + void set_verbose (bool verbose) { d_verbose = verbose; } + + void set_gain_mu (float gain_mu) { d_gain_mu = gain_mu; } + void set_gain_omega (float gain_omega) { d_gain_omega = gain_omega; } + void set_mu (float mu) { d_mu = mu; } + void set_omega (float omega) { + d_omega = omega; + d_min_omega = omega*(1.0 - d_omega_relative_limit); + d_max_omega = omega*(1.0 + d_omega_relative_limit); + d_omega_mid = 0.5*(d_min_omega+d_max_omega); + } + +protected: + digital_clock_recovery_mm_cc (float omega, float gain_omega, + float mu, float gain_mu, + float omega_relative_limi); + + private: + float d_mu; + float d_omega; + float d_gain_omega; + float d_min_omega; // minimum allowed omega + float d_max_omega; // maximum allowed omeg + float d_omega_relative_limit; // used to compute min and max omega + float d_omega_mid; + float d_gain_mu; + gr_complex d_last_sample; + gri_mmse_fir_interpolator_cc *d_interp; + bool d_verbose; + + gr_complex d_p_2T; + gr_complex d_p_1T; + gr_complex d_p_0T; + + gr_complex d_c_2T; + gr_complex d_c_1T; + gr_complex d_c_0T; + + gr_complex slicer_0deg (gr_complex sample); + gr_complex slicer_45deg (gr_complex sample); + + friend digital_clock_recovery_mm_cc_sptr + digital_make_clock_recovery_mm_cc (float omega, float gain_omega, + float mu, float gain_mu, + float omega_relative_limit); +}; + +#endif diff --git a/gr-digital/lib/digital_clock_recovery_mm_ff.cc b/gr-digital/lib/digital_clock_recovery_mm_ff.cc new file mode 100644 index 000000000..04057f0e9 --- /dev/null +++ b/gr-digital/lib/digital_clock_recovery_mm_ff.cc @@ -0,0 +1,139 @@ +/* -*- c++ -*- */ +/* + * Copyright 2004,2010,2011 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 <gr_io_signature.h> +#include <digital_clock_recovery_mm_ff.h> +#include <gri_mmse_fir_interpolator.h> +#include <stdexcept> + +#define DEBUG_CR_MM_FF 0 // must be defined as 0 or 1 + +// Public constructor + +digital_clock_recovery_mm_ff_sptr +digital_make_clock_recovery_mm_ff(float omega, float gain_omega, + float mu, float gain_mu, + float omega_relative_limit) +{ + return gnuradio::get_initial_sptr(new digital_clock_recovery_mm_ff (omega, + gain_omega, + mu, + gain_mu, + omega_relative_limit)); +} + +digital_clock_recovery_mm_ff::digital_clock_recovery_mm_ff (float omega, float gain_omega, + float mu, float gain_mu, + float omega_relative_limit) + : gr_block ("clock_recovery_mm_ff", + gr_make_io_signature (1, 1, sizeof (float)), + gr_make_io_signature (1, 1, sizeof (float))), + d_mu (mu), d_gain_omega(gain_omega), d_gain_mu(gain_mu), + d_last_sample(0), d_interp(new gri_mmse_fir_interpolator()), + d_logfile(0), d_omega_relative_limit(omega_relative_limit) +{ + if (omega < 1) + throw std::out_of_range ("clock rate must be > 0"); + if (gain_mu < 0 || gain_omega < 0) + throw std::out_of_range ("Gains must be non-negative"); + + set_omega(omega); // also sets min and max omega + set_relative_rate (1.0 / omega); + + if (DEBUG_CR_MM_FF) + d_logfile = fopen("cr_mm_ff.dat", "wb"); +} + +digital_clock_recovery_mm_ff::~digital_clock_recovery_mm_ff () +{ + delete d_interp; + + if (DEBUG_CR_MM_FF && d_logfile){ + fclose(d_logfile); + d_logfile = 0; + } +} + +void +digital_clock_recovery_mm_ff::forecast(int noutput_items, gr_vector_int &ninput_items_required) +{ + unsigned ninputs = ninput_items_required.size(); + for (unsigned i=0; i < ninputs; i++) + ninput_items_required[i] = + (int) ceil((noutput_items * d_omega) + d_interp->ntaps()); +} + +static inline float +slice(float x) +{ + return x < 0 ? -1.0F : 1.0F; +} + +/* + * This implements the Mueller and Müller (M&M) discrete-time error-tracking synchronizer. + * + * See "Digital Communication Receivers: Synchronization, Channel + * Estimation and Signal Processing" by Heinrich Meyr, Marc Moeneclaey, & Stefan Fechtel. + * ISBN 0-471-50275-8. + */ +int +digital_clock_recovery_mm_ff::general_work (int noutput_items, + gr_vector_int &ninput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items) +{ + const float *in = (const float *) input_items[0]; + float *out = (float *) output_items[0]; + + int ii = 0; // input index + int oo = 0; // output index + int ni = ninput_items[0] - d_interp->ntaps(); // don't use more input than this + float mm_val; + + while (oo < noutput_items && ii < ni ){ + + // produce output sample + out[oo] = d_interp->interpolate (&in[ii], d_mu); + mm_val = slice(d_last_sample) * out[oo] - slice(out[oo]) * d_last_sample; + d_last_sample = out[oo]; + + d_omega = d_omega + d_gain_omega * mm_val; + d_omega = d_omega_mid + gr_branchless_clip(d_omega-d_omega_mid, d_omega_relative_limit); // make sure we don't walk away + d_mu = d_mu + d_omega + d_gain_mu * mm_val; + + ii += (int) floor(d_mu); + d_mu = d_mu - floor(d_mu); + oo++; + + if (DEBUG_CR_MM_FF && d_logfile){ + fwrite(&d_omega, sizeof(d_omega), 1, d_logfile); + } + } + + consume_each (ii); + + return oo; +} diff --git a/gr-digital/lib/digital_clock_recovery_mm_ff.h b/gr-digital/lib/digital_clock_recovery_mm_ff.h new file mode 100644 index 000000000..6fc5ac261 --- /dev/null +++ b/gr-digital/lib/digital_clock_recovery_mm_ff.h @@ -0,0 +1,98 @@ +/* -*- c++ -*- */ +/* + * Copyright 2004,2011 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_CLOCK_RECOVERY_MM_FF_H +#define INCLUDED_DIGITAL_CLOCK_RECOVERY_MM_FF_H + +#include <gr_block.h> +#include <gr_math.h> +#include <stdio.h> + +class gri_mmse_fir_interpolator; + +class digital_clock_recovery_mm_ff; +typedef boost::shared_ptr<digital_clock_recovery_mm_ff> digital_clock_recovery_mm_ff_sptr; + +// public constructor +digital_clock_recovery_mm_ff_sptr +digital_make_clock_recovery_mm_ff (float omega, float gain_omega, + float mu, float gain_mu, + float omega_relative_limit=0.001); + +/*! + * \brief Mueller and Müller (M&M) based clock recovery block with float input, float output. + * \ingroup sync_blk + * + * This implements the Mueller and Müller (M&M) discrete-time error-tracking synchronizer. + * + * See "Digital Communication Receivers: Synchronization, Channel + * Estimation and Signal Processing" by Heinrich Meyr, Marc Moeneclaey, & Stefan Fechtel. + * ISBN 0-471-50275-8. + */ +class digital_clock_recovery_mm_ff : public gr_block +{ + public: + ~digital_clock_recovery_mm_ff (); + 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); + float mu() const { return d_mu;} + float omega() const { return d_omega;} + float gain_mu() const { return d_gain_mu;} + float gain_omega() const { return d_gain_omega;} + + void set_gain_mu (float gain_mu) { d_gain_mu = gain_mu; } + void set_gain_omega (float gain_omega) { d_gain_omega = gain_omega; } + void set_mu (float mu) { d_mu = mu; } + void set_omega (float omega){ + d_omega = omega; + d_min_omega = omega*(1.0 - d_omega_relative_limit); + d_max_omega = omega*(1.0 + d_omega_relative_limit); + d_omega_mid = 0.5*(d_min_omega+d_max_omega); + } + +protected: + digital_clock_recovery_mm_ff (float omega, float gain_omega, float mu, float gain_mu, + float omega_relative_limit); + + private: + float d_mu; // fractional sample position [0.0, 1.0] + float d_omega; // nominal frequency + float d_min_omega; // minimum allowed omega + float d_omega_mid; // average omega + float d_max_omega; // maximum allowed omega + float d_gain_omega; // gain for adjusting omega + float d_gain_mu; // gain for adjusting mu + float d_last_sample; + gri_mmse_fir_interpolator *d_interp; + FILE *d_logfile; + float d_omega_relative_limit; // used to compute min and max omega + + friend digital_clock_recovery_mm_ff_sptr + digital_make_clock_recovery_mm_ff (float omega, float gain_omega, + float mu, float gain_mu, + float omega_relative_limit); +}; + +#endif 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..3dfc70273 --- /dev/null +++ b/gr-digital/lib/digital_constellation.cc @@ -0,0 +1,550 @@ +/* -*- 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_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_pre_diff_code.resize(4); + d_pre_diff_code[0] = 0x0; + d_pre_diff_code[1] = 0x2; + d_pre_diff_code[2] = 0x3; + d_pre_diff_code[3] = 0x1; + + 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); + + /* + bool a = real(*sample) > 0; + bool b = imag(*sample) > 0; + if(a) { + if(b) + return 0x0; + else + return 0x1; + } + else { + if(b) + return 0x2; + else + return 0x3; + } + */ +} + + +/********************************************************************/ + + +digital_constellation_dqpsk_sptr +digital_make_constellation_dqpsk() +{ + return digital_constellation_dqpsk_sptr(new digital_constellation_dqpsk ()); +} + +digital_constellation_dqpsk::digital_constellation_dqpsk () +{ + // This constellation is not gray coded, which allows + // us to use differential encodings (through gr_diff_encode and + // gr_diff_decode) on the symbols. + d_constellation.resize(4); + 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); + + // Use this mapping to convert to gray code before diff enc. + d_pre_diff_code.resize(4); + d_pre_diff_code[0] = 0x0; + d_pre_diff_code[1] = 0x1; + d_pre_diff_code[2] = 0x3; + d_pre_diff_code[3] = 0x2; + d_apply_pre_diff_code = true; + + d_rotational_symmetry = 4; + d_dimensionality = 1; + calc_arity(); +} + +unsigned int +digital_constellation_dqpsk::decision_maker(const gr_complex *sample) +{ + // Slower deicison maker as we can't slice along one axis. + // Maybe there's a better way to do this, still. + + bool a = real(*sample) > 0; + bool b = imag(*sample) > 0; + if(a) { + if(b) + return 0x0; + else + return 0x3; + } + else { + if(b) + return 0x1; + else + return 0x2; + } +} + +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..3e54e7d96 --- /dev/null +++ b/gr-digital/lib/digital_constellation.h @@ -0,0 +1,394 @@ +/* -*- 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;} + //! Whether to apply an encoding before doing differential encoding. (e.g. gray coding) + void set_pre_diff_code(bool a) { d_apply_pre_diff_code = a;} + //! 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_dqpsk */ +/* */ +/* Works with differential encoding; slower decisions. */ +/* */ +/************************************************************/ + +//! \brief DQPSK-specific constellation and decision maker +class digital_constellation_dqpsk; +typedef boost::shared_ptr<digital_constellation_dqpsk> digital_constellation_dqpsk_sptr; + +// public constructor +digital_constellation_dqpsk_sptr +digital_make_constellation_dqpsk (); + +class digital_constellation_dqpsk : public digital_constellation +{ + public: + + digital_constellation_dqpsk (); + unsigned int decision_maker (const gr_complex *sample); + + friend digital_constellation_dqpsk_sptr + digital_make_constellation_dqpsk (); + +}; + + +/************************************************************/ +/* 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..b9239962a --- /dev/null +++ b/gr-digital/lib/digital_constellation_receiver_cb.cc @@ -0,0 +1,123 @@ +/* -*- 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 loop_bw, float fmin, float fmax) +{ + return gnuradio::get_initial_sptr(new digital_constellation_receiver_cb (constell, + loop_bw, + 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 loop_bw, 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)), + gri_control_loop(loop_bw, fmax, fmin), + d_constellation(constellation), + 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) +{ + advance_loop(phase_error); + phase_wrap(); + frequency_limit(); + +#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_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..0ac80450f --- /dev/null +++ b/gr-digital/lib/digital_constellation_receiver_cb.h @@ -0,0 +1,114 @@ +/* -*- 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 <gri_control_loop.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 loop_bw, 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 gri_control_loop +{ +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); + +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 loop_bw, float fmin, float fmax); + + void phase_error_tracking(float phase_error); + +private: + unsigned int d_M; + + 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 loop_bw, float fmin, float fmax); +}; + +#endif diff --git a/gr-digital/lib/digital_correlate_access_code_bb.cc b/gr-digital/lib/digital_correlate_access_code_bb.cc new file mode 100644 index 000000000..f21b57d92 --- /dev/null +++ b/gr-digital/lib/digital_correlate_access_code_bb.cc @@ -0,0 +1,134 @@ +/* -*- c++ -*- */ +/* + * Copyright 2004,2006,2010,2011 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_correlate_access_code_bb.h> +#include <gr_io_signature.h> +#include <stdexcept> +#include <gr_count_bits.h> +#include <cstdio> + + +#define VERBOSE 0 + + +digital_correlate_access_code_bb_sptr +digital_make_correlate_access_code_bb (const std::string &access_code, int threshold) +{ + return gnuradio::get_initial_sptr(new digital_correlate_access_code_bb + (access_code, threshold)); +} + + +digital_correlate_access_code_bb::digital_correlate_access_code_bb ( + const std::string &access_code, int threshold) + : gr_sync_block ("correlate_access_code_bb", + gr_make_io_signature (1, 1, sizeof(char)), + gr_make_io_signature (1, 1, sizeof(char))), + d_data_reg(0), d_flag_reg(0), d_flag_bit(0), d_mask(0), + d_threshold(threshold) + +{ + if (!set_access_code(access_code)){ + fprintf(stderr, "digital_correlate_access_code_bb: access_code is > 64 bits\n"); + throw std::out_of_range ("access_code is > 64 bits"); + } +} + +digital_correlate_access_code_bb::~digital_correlate_access_code_bb () +{ +} + +bool +digital_correlate_access_code_bb::set_access_code( + const std::string &access_code) +{ + unsigned len = access_code.length(); // # of bytes in string + if (len > 64) + return false; + + // set len top bits to 1. + d_mask = ((~0ULL) >> (64 - len)) << (64 - len); + + d_flag_bit = 1LL << (64 - len); // Where we or-in new flag values. + // new data always goes in 0x0000000000000001 + d_access_code = 0; + for (unsigned i=0; i < 64; i++){ + d_access_code <<= 1; + if (i < len) + d_access_code |= access_code[i] & 1; // look at LSB only + } + + return true; +} + +int +digital_correlate_access_code_bb::work (int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items) +{ + const unsigned char *in = (const unsigned char *) input_items[0]; + unsigned char *out = (unsigned char *) output_items[0]; + + for (int i = 0; i < noutput_items; i++){ + + // compute output value + unsigned int t = 0; + + t |= ((d_data_reg >> 63) & 0x1) << 0; + t |= ((d_flag_reg >> 63) & 0x1) << 1; // flag bit + out[i] = t; + + // compute hamming distance between desired access code and current data + unsigned long long wrong_bits = 0; + unsigned int nwrong = d_threshold+1; + int new_flag = 0; + + wrong_bits = (d_data_reg ^ d_access_code) & d_mask; + nwrong = gr_count_bits64(wrong_bits); + + // test for access code with up to threshold errors + new_flag = (nwrong <= d_threshold); + +#if VERBOSE + if(new_flag) { + fprintf(stderr, "access code found: %llx\n", d_access_code); + } + else { + fprintf(stderr, "%llx ==> %llx\n", d_access_code, d_data_reg); + } +#endif + + // shift in new data and new flag + d_data_reg = (d_data_reg << 1) | (in[i] & 0x1); + d_flag_reg = (d_flag_reg << 1); + if (new_flag) { + d_flag_reg |= d_flag_bit; + } + } + + return noutput_items; +} + diff --git a/gr-digital/lib/digital_correlate_access_code_bb.h b/gr-digital/lib/digital_correlate_access_code_bb.h new file mode 100644 index 000000000..2607ae84c --- /dev/null +++ b/gr-digital/lib/digital_correlate_access_code_bb.h @@ -0,0 +1,83 @@ +/* -*- c++ -*- */ +/* + * Copyright 2005,2006,2011 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_CORRELATE_ACCESS_CODE_BB_H +#define INCLUDED_DIGITAL_CORRELATE_ACCESS_CODE_BB_H + +#include <gr_sync_block.h> +#include <string> + +class digital_correlate_access_code_bb; +typedef boost::shared_ptr<digital_correlate_access_code_bb> digital_correlate_access_code_bb_sptr; + +/*! + * \param access_code is represented with 1 byte per bit, e.g., "010101010111000100" + * \param threshold maximum number of bits that may be wrong + */ +digital_correlate_access_code_bb_sptr +digital_make_correlate_access_code_bb (const std::string &access_code, int threshold); + +/*! + * \brief Examine input for specified access code, one bit at a time. + * \ingroup sync_blk + * + * input: stream of bits, 1 bit per input byte (data in LSB) + * output: stream of bits, 2 bits per output byte (data in LSB, flag in next higher bit) + * + * Each output byte contains two valid bits, the data bit, and the + * flag bit. The LSB (bit 0) is the data bit, and is the original + * input data, delayed 64 bits. Bit 1 is the + * flag bit and is 1 if the corresponding data bit is the first data + * bit following the access code. Otherwise the flag bit is 0. + */ +class digital_correlate_access_code_bb : public gr_sync_block +{ + friend digital_correlate_access_code_bb_sptr + digital_make_correlate_access_code_bb (const std::string &access_code, int threshold); + private: + unsigned long long d_access_code; // access code to locate start of packet + // access code is left justified in the word + unsigned long long d_data_reg; // used to look for access_code + unsigned long long d_flag_reg; // keep track of decisions + unsigned long long d_flag_bit; // mask containing 1 bit which is location of new flag + unsigned long long d_mask; // masks access_code bits (top N bits are set where + // N is the number of bits in the access code) + unsigned int d_threshold; // how many bits may be wrong in sync vector + + protected: + digital_correlate_access_code_bb(const std::string &access_code, int threshold); + + public: + ~digital_correlate_access_code_bb(); + + int work(int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items); + + + /*! + * \param access_code is represented with 1 byte per bit, e.g., "010101010111000100" + */ + bool set_access_code (const std::string &access_code); +}; + +#endif /* INCLUDED_DIGITAL_CORRELATE_ACCESS_CODE_BB_H */ 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..370dc7e5c --- /dev/null +++ b/gr-digital/lib/digital_costas_loop_cc.cc @@ -0,0 +1,153 @@ +/* -*- 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> + +digital_costas_loop_cc_sptr +digital_make_costas_loop_cc (float loop_bw, int order + ) throw (std::invalid_argument) +{ + return gnuradio::get_initial_sptr(new digital_costas_loop_cc + (loop_bw, order)); +} + +digital_costas_loop_cc::digital_costas_loop_cc (float loop_bw, 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))), + gri_control_loop(loop_bw, 1.0, -1.0), + d_order(order), d_phase_detector(NULL) +{ + // Set up the phase detector to use based on the constellation order + 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()); +} + +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); + + advance_loop(error); + phase_wrap(); + frequency_limit(); + + 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); + + advance_loop(error); + phase_wrap(); + frequency_limit(); + } + } + 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..7b2cd6dad --- /dev/null +++ b/gr-digital/lib/digital_costas_loop_cc.h @@ -0,0 +1,115 @@ +/* -*- 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 <gri_control_loop.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 loop_bw, 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, public gri_control_loop +{ + friend digital_costas_loop_cc_sptr + digital_make_costas_loop_cc (float loop_bw, int order + ) throw (std::invalid_argument); + + int d_order; + + digital_costas_loop_cc (float loop_bw, int order + ) throw (std::invalid_argument); + + /*! \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: + + int work (int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items); +}; + +#endif diff --git a/gr-digital/lib/digital_crc32.cc b/gr-digital/lib/digital_crc32.cc new file mode 100644 index 000000000..8806d6e9c --- /dev/null +++ b/gr-digital/lib/digital_crc32.cc @@ -0,0 +1,130 @@ +/* -*- c++ -*- */ +/* + * Copyright 2005,2011 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. + */ + +/* + * See also ISO 3309 [ISO-3309] or ITU-T V.42 [ITU-V42] for a formal specification. + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif +#include <digital_crc32.h> + + +// Automatically generated CRC function +// polynomial: 0x104C11DB7 +unsigned int +digital_update_crc32(unsigned int crc, const unsigned char *data, size_t len) +{ + static const unsigned int table[256] = { + 0x00000000U,0x04C11DB7U,0x09823B6EU,0x0D4326D9U, + 0x130476DCU,0x17C56B6BU,0x1A864DB2U,0x1E475005U, + 0x2608EDB8U,0x22C9F00FU,0x2F8AD6D6U,0x2B4BCB61U, + 0x350C9B64U,0x31CD86D3U,0x3C8EA00AU,0x384FBDBDU, + 0x4C11DB70U,0x48D0C6C7U,0x4593E01EU,0x4152FDA9U, + 0x5F15ADACU,0x5BD4B01BU,0x569796C2U,0x52568B75U, + 0x6A1936C8U,0x6ED82B7FU,0x639B0DA6U,0x675A1011U, + 0x791D4014U,0x7DDC5DA3U,0x709F7B7AU,0x745E66CDU, + 0x9823B6E0U,0x9CE2AB57U,0x91A18D8EU,0x95609039U, + 0x8B27C03CU,0x8FE6DD8BU,0x82A5FB52U,0x8664E6E5U, + 0xBE2B5B58U,0xBAEA46EFU,0xB7A96036U,0xB3687D81U, + 0xAD2F2D84U,0xA9EE3033U,0xA4AD16EAU,0xA06C0B5DU, + 0xD4326D90U,0xD0F37027U,0xDDB056FEU,0xD9714B49U, + 0xC7361B4CU,0xC3F706FBU,0xCEB42022U,0xCA753D95U, + 0xF23A8028U,0xF6FB9D9FU,0xFBB8BB46U,0xFF79A6F1U, + 0xE13EF6F4U,0xE5FFEB43U,0xE8BCCD9AU,0xEC7DD02DU, + 0x34867077U,0x30476DC0U,0x3D044B19U,0x39C556AEU, + 0x278206ABU,0x23431B1CU,0x2E003DC5U,0x2AC12072U, + 0x128E9DCFU,0x164F8078U,0x1B0CA6A1U,0x1FCDBB16U, + 0x018AEB13U,0x054BF6A4U,0x0808D07DU,0x0CC9CDCAU, + 0x7897AB07U,0x7C56B6B0U,0x71159069U,0x75D48DDEU, + 0x6B93DDDBU,0x6F52C06CU,0x6211E6B5U,0x66D0FB02U, + 0x5E9F46BFU,0x5A5E5B08U,0x571D7DD1U,0x53DC6066U, + 0x4D9B3063U,0x495A2DD4U,0x44190B0DU,0x40D816BAU, + 0xACA5C697U,0xA864DB20U,0xA527FDF9U,0xA1E6E04EU, + 0xBFA1B04BU,0xBB60ADFCU,0xB6238B25U,0xB2E29692U, + 0x8AAD2B2FU,0x8E6C3698U,0x832F1041U,0x87EE0DF6U, + 0x99A95DF3U,0x9D684044U,0x902B669DU,0x94EA7B2AU, + 0xE0B41DE7U,0xE4750050U,0xE9362689U,0xEDF73B3EU, + 0xF3B06B3BU,0xF771768CU,0xFA325055U,0xFEF34DE2U, + 0xC6BCF05FU,0xC27DEDE8U,0xCF3ECB31U,0xCBFFD686U, + 0xD5B88683U,0xD1799B34U,0xDC3ABDEDU,0xD8FBA05AU, + 0x690CE0EEU,0x6DCDFD59U,0x608EDB80U,0x644FC637U, + 0x7A089632U,0x7EC98B85U,0x738AAD5CU,0x774BB0EBU, + 0x4F040D56U,0x4BC510E1U,0x46863638U,0x42472B8FU, + 0x5C007B8AU,0x58C1663DU,0x558240E4U,0x51435D53U, + 0x251D3B9EU,0x21DC2629U,0x2C9F00F0U,0x285E1D47U, + 0x36194D42U,0x32D850F5U,0x3F9B762CU,0x3B5A6B9BU, + 0x0315D626U,0x07D4CB91U,0x0A97ED48U,0x0E56F0FFU, + 0x1011A0FAU,0x14D0BD4DU,0x19939B94U,0x1D528623U, + 0xF12F560EU,0xF5EE4BB9U,0xF8AD6D60U,0xFC6C70D7U, + 0xE22B20D2U,0xE6EA3D65U,0xEBA91BBCU,0xEF68060BU, + 0xD727BBB6U,0xD3E6A601U,0xDEA580D8U,0xDA649D6FU, + 0xC423CD6AU,0xC0E2D0DDU,0xCDA1F604U,0xC960EBB3U, + 0xBD3E8D7EU,0xB9FF90C9U,0xB4BCB610U,0xB07DABA7U, + 0xAE3AFBA2U,0xAAFBE615U,0xA7B8C0CCU,0xA379DD7BU, + 0x9B3660C6U,0x9FF77D71U,0x92B45BA8U,0x9675461FU, + 0x8832161AU,0x8CF30BADU,0x81B02D74U,0x857130C3U, + 0x5D8A9099U,0x594B8D2EU,0x5408ABF7U,0x50C9B640U, + 0x4E8EE645U,0x4A4FFBF2U,0x470CDD2BU,0x43CDC09CU, + 0x7B827D21U,0x7F436096U,0x7200464FU,0x76C15BF8U, + 0x68860BFDU,0x6C47164AU,0x61043093U,0x65C52D24U, + 0x119B4BE9U,0x155A565EU,0x18197087U,0x1CD86D30U, + 0x029F3D35U,0x065E2082U,0x0B1D065BU,0x0FDC1BECU, + 0x3793A651U,0x3352BBE6U,0x3E119D3FU,0x3AD08088U, + 0x2497D08DU,0x2056CD3AU,0x2D15EBE3U,0x29D4F654U, + 0xC5A92679U,0xC1683BCEU,0xCC2B1D17U,0xC8EA00A0U, + 0xD6AD50A5U,0xD26C4D12U,0xDF2F6BCBU,0xDBEE767CU, + 0xE3A1CBC1U,0xE760D676U,0xEA23F0AFU,0xEEE2ED18U, + 0xF0A5BD1DU,0xF464A0AAU,0xF9278673U,0xFDE69BC4U, + 0x89B8FD09U,0x8D79E0BEU,0x803AC667U,0x84FBDBD0U, + 0x9ABC8BD5U,0x9E7D9662U,0x933EB0BBU,0x97FFAD0CU, + 0xAFB010B1U,0xAB710D06U,0xA6322BDFU,0xA2F33668U, + 0xBCB4666DU,0xB8757BDAU,0xB5365D03U,0xB1F740B4U, + }; + + while (len > 0) + { + crc = table[*data ^ ((crc >> 24) & 0xff)] ^ (crc << 8); + data++; + len--; + } + return crc; +} + +unsigned int +digital_update_crc32(unsigned int crc, const std::string s) +{ + return digital_update_crc32(crc, (const unsigned char *) s.data(), s.size()); +} + +unsigned int +digital_crc32(const unsigned char *buf, size_t len) +{ + return digital_update_crc32(0xffffffff, buf, len) ^ 0xffffffff; +} + +unsigned int +digital_crc32(const std::string s) +{ + return digital_crc32((const unsigned char *) s.data(), s.size()); +} diff --git a/gr-digital/lib/digital_crc32.h b/gr-digital/lib/digital_crc32.h new file mode 100644 index 000000000..64aa12f7b --- /dev/null +++ b/gr-digital/lib/digital_crc32.h @@ -0,0 +1,50 @@ +/* -*- c++ -*- */ +/* + * Copyright 2005,2011 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_CRC32_H +#define INCLUDED_DIGITAL_CRC32_H + +#include <string> +#include <gr_types.h> + +/*! + * \brief update running CRC-32 + * \ingroup misc + * + * Update a running CRC with the bytes buf[0..len-1] The CRC should be + * initialized to all 1's, and the transmitted value is the 1's + * complement of the final running CRC. The resulting CRC should be + * transmitted in big endian order. + */ +unsigned int +digital_update_crc32(unsigned int crc, const unsigned char *buf, size_t len); + +unsigned int +digital_update_crc32(unsigned int crc, const std::string buf); + +unsigned int +digital_crc32(const unsigned char *buf, size_t len); + +unsigned int +digital_crc32(const std::string buf); + +#endif /* INCLUDED_CRC32_H */ diff --git a/gr-digital/lib/digital_fll_band_edge_cc.cc b/gr-digital/lib/digital_fll_band_edge_cc.cc new file mode 100644 index 000000000..05c092622 --- /dev/null +++ b/gr-digital/lib/digital_fll_band_edge_cc.cc @@ -0,0 +1,259 @@ +/* -*- c++ -*- */ +/* + * Copyright 2009-2011 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_fll_band_edge_cc.h> +#include <gr_io_signature.h> +#include <gr_expj.h> +#include <cstdio> + +#define M_TWOPI (2*M_PI) + +float sinc(float x) +{ + if(x == 0) + return 1; + else + return sin(M_PI*x)/(M_PI*x); +} + +digital_fll_band_edge_cc_sptr +digital_make_fll_band_edge_cc (float samps_per_sym, float rolloff, + int filter_size, float bandwidth) +{ + return gnuradio::get_initial_sptr(new digital_fll_band_edge_cc (samps_per_sym, rolloff, + filter_size, bandwidth)); +} + + +static int ios[] = {sizeof(gr_complex), sizeof(float), sizeof(float), sizeof(float)}; +static std::vector<int> iosig(ios, ios+sizeof(ios)/sizeof(int)); +digital_fll_band_edge_cc::digital_fll_band_edge_cc (float samps_per_sym, float rolloff, + int filter_size, float bandwidth) + : gr_sync_block ("fll_band_edge_cc", + gr_make_io_signature (1, 1, sizeof(gr_complex)), + gr_make_io_signaturev (1, 4, iosig)), + gri_control_loop(bandwidth, M_TWOPI*(2.0/samps_per_sym), -M_TWOPI*(2.0/samps_per_sym)), + d_updated (false) +{ + // Initialize samples per symbol + if(samps_per_sym <= 0) { + throw std::out_of_range ("digital_fll_band_edge_cc: invalid number of sps. Must be > 0."); + } + d_sps = samps_per_sym; + + // Initialize rolloff factor + if(rolloff < 0 || rolloff > 1.0) { + throw std::out_of_range ("digital_fll_band_edge_cc: invalid rolloff factor. Must be in [0,1]."); + } + d_rolloff = rolloff; + + // Initialize filter length + if(filter_size <= 0) { + throw std::out_of_range ("digital_fll_band_edge_cc: invalid filter size. Must be > 0."); + } + d_filter_size = filter_size; + + // Build the band edge filters + design_filter(d_sps, d_rolloff, d_filter_size); +} + +digital_fll_band_edge_cc::~digital_fll_band_edge_cc () +{ +} + + +/******************************************************************* + SET FUNCTIONS +*******************************************************************/ + +void +digital_fll_band_edge_cc::set_samples_per_symbol(float sps) +{ + if(sps <= 0) { + throw std::out_of_range ("digital_fll_band_edge_cc: invalid number of sps. Must be > 0."); + } + d_sps = sps; + design_filter(d_sps, d_rolloff, d_filter_size); +} + +void +digital_fll_band_edge_cc::set_rolloff(float rolloff) +{ + if(rolloff < 0 || rolloff > 1.0) { + throw std::out_of_range ("digital_fll_band_edge_cc: invalid rolloff factor. Must be in [0,1]."); + } + d_rolloff = rolloff; + design_filter(d_sps, d_rolloff, d_filter_size); +} + +void +digital_fll_band_edge_cc::set_filter_size(int filter_size) +{ + if(filter_size <= 0) { + throw std::out_of_range ("digital_fll_band_edge_cc: invalid filter size. Must be > 0."); + } + d_filter_size = filter_size; + design_filter(d_sps, d_rolloff, d_filter_size); +} + +/******************************************************************* + GET FUNCTIONS +*******************************************************************/ + +float +digital_fll_band_edge_cc::get_samples_per_symbol() const +{ + return d_sps; +} + +float +digital_fll_band_edge_cc::get_rolloff() const +{ + return d_rolloff; +} + +int +digital_fll_band_edge_cc:: get_filter_size() const +{ + return d_filter_size; +} + + +/******************************************************************* +*******************************************************************/ + +void +digital_fll_band_edge_cc::design_filter(float samps_per_sym, + float rolloff, int filter_size) +{ + int M = rint(filter_size / samps_per_sym); + float power = 0; + + // Create the baseband filter by adding two sincs together + std::vector<float> bb_taps; + for(int i = 0; i < filter_size; i++) { + float k = -M + i*2.0/samps_per_sym; + float tap = sinc(rolloff*k - 0.5) + sinc(rolloff*k + 0.5); + power += tap; + + bb_taps.push_back(tap); + } + + d_taps_lower.resize(filter_size); + d_taps_upper.resize(filter_size); + + // Create the band edge filters by spinning the baseband + // filter up and down to the right places in frequency. + // Also, normalize the power in the filters + int N = (bb_taps.size() - 1.0)/2.0; + for(int i = 0; i < filter_size; i++) { + float tap = bb_taps[i] / power; + + float k = (-N + (int)i)/(2.0*samps_per_sym); + + gr_complex t1 = tap * gr_expj(-M_TWOPI*(1+rolloff)*k); + gr_complex t2 = tap * gr_expj(M_TWOPI*(1+rolloff)*k); + + d_taps_lower[filter_size-i-1] = t1; + d_taps_upper[filter_size-i-1] = t2; + } + + d_updated = true; + + // Set the history to ensure enough input items for each filter + set_history(filter_size+1); +} + +void +digital_fll_band_edge_cc::print_taps() +{ + unsigned int i; + + printf("Upper Band-edge: ["); + for(i = 0; i < d_taps_upper.size(); i++) { + printf(" %.4e + %.4ej,", d_taps_upper[i].real(), d_taps_upper[i].imag()); + } + printf("]\n\n"); + + printf("Lower Band-edge: ["); + for(i = 0; i < d_taps_lower.size(); i++) { + printf(" %.4e + %.4ej,", d_taps_lower[i].real(), d_taps_lower[i].imag()); + } + printf("]\n\n"); +} + +int +digital_fll_band_edge_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]; + + float *frq = NULL; + float *phs = NULL; + float *err = NULL; + if(output_items.size() == 4) { + frq = (float *) output_items[1]; + phs = (float *) output_items[2]; + err = (float *) output_items[3]; + } + + if (d_updated) { + d_updated = false; + return 0; // history requirements may have changed. + } + + int i; + float error; + gr_complex nco_out; + gr_complex out_upper, out_lower; + for(i = 0; i < noutput_items; i++) { + nco_out = gr_expj(d_phase); + out[i+d_filter_size-1] = in[i] * nco_out; + + // Perform the dot product of the output with the filters + out_upper = 0; + out_lower = 0; + for(int k = 0; k < d_filter_size; k++) { + out_upper += d_taps_upper[k] * out[i+k]; + out_lower += d_taps_lower[k] * out[i+k]; + } + error = norm(out_lower) - norm(out_upper); + + advance_loop(error); + phase_wrap(); + frequency_limit(); + + if(output_items.size() == 4) { + frq[i] = d_freq; + phs[i] = d_phase; + err[i] = error; + } + } + + return noutput_items; +} diff --git a/gr-digital/lib/digital_fll_band_edge_cc.h b/gr-digital/lib/digital_fll_band_edge_cc.h new file mode 100644 index 000000000..4fa7b3a3e --- /dev/null +++ b/gr-digital/lib/digital_fll_band_edge_cc.h @@ -0,0 +1,212 @@ +/* -*- c++ -*- */ +/* + * Copyright 2009,2011 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_FLL_BAND_EDGE_CC_H +#define INCLUDED_DIGITAL_FLL_BAND_EDGE_CC_H + +#include <gr_sync_block.h> +#include <gri_control_loop.h> + +class digital_fll_band_edge_cc; +typedef boost::shared_ptr<digital_fll_band_edge_cc> digital_fll_band_edge_cc_sptr; +digital_fll_band_edge_cc_sptr digital_make_fll_band_edge_cc (float samps_per_sym, + float rolloff, + int filter_size, + float bandwidth); + +/*! + * \class digital_fll_band_edge_cc + * \brief Frequency Lock Loop using band-edge filters + * + * \ingroup general + * + * The frequency lock loop derives a band-edge filter that covers the + * upper and lower bandwidths of a digitally-modulated signal. The + * bandwidth range is determined by the excess bandwidth (e.g., + * rolloff factor) of the modulated signal. The placement in frequency + * of the band-edges is determined by the oversampling ratio (number + * of samples per symbol) and the excess bandwidth. The size of the + * filters should be fairly large so as to average over a number of + * symbols. + * + * The FLL works by filtering the upper and lower band edges into + * x_u(t) and x_l(t), respectively. These are combined to form cc(t) + * = x_u(t) + x_l(t) and ss(t) = x_u(t) - x_l(t). Combining these to + * form the signal e(t) = Re{cc(t) \\times ss(t)^*} (where ^* is the + * complex conjugate) provides an error signal at the DC term that is + * directly proportional to the carrier frequency. We then make a + * second-order loop using the error signal that is the running + * average of e(t). + * + * In practice, the above equation can be simplified by just comparing + * the absolute value squared of the output of both filters: + * abs(x_l(t))^2 - abs(x_u(t))^2 = norm(x_l(t)) - norm(x_u(t)). + * + * In theory, the band-edge filter is the derivative of the matched + * filter in frequency, (H_be(f) = \\frac{H(f)}{df}. In practice, this + * comes down to a quarter sine wave at the point of the matched + * filter's rolloff (if it's a raised-cosine, the derivative of a + * cosine is a sine). Extend this sine by another quarter wave to + * make a half wave around the band-edges is equivalent in time to the + * sum of two sinc functions. The baseband filter fot the band edges + * is therefore derived from this sum of sincs. The band edge filters + * are then just the baseband signal modulated to the correct place in + * frequency. All of these calculations are done in the + * 'design_filter' function. + * + * Note: We use FIR filters here because the filters have to have a + * flat phase response over the entire frequency range to allow their + * comparisons to be valid. + * + * It is very important that the band edge filters be the derivatives + * of the pulse shaping filter, and that they be linear + * phase. Otherwise, the variance of the error will be very large. + * + */ + +class digital_fll_band_edge_cc : public gr_sync_block, public gri_control_loop +{ + private: + /*! + * Build the FLL + * \param samps_per_sym (float) Number of samples per symbol of signal + * \param rolloff (float) Rolloff factor of signal + * \param filter_size (int) Size (in taps) of the filter + * \param bandwidth (float) Loop bandwidth + */ + friend digital_fll_band_edge_cc_sptr digital_make_fll_band_edge_cc (float samps_per_sym, + float rolloff, + int filter_size, + float bandwidth); + + float d_sps; + float d_rolloff; + int d_filter_size; + + std::vector<gr_complex> d_taps_lower; + std::vector<gr_complex> d_taps_upper; + bool d_updated; + + /*! + * Build the FLL + * \param samps_per_sym (float) number of samples per symbol + * \param rolloff (float) Rolloff (excess bandwidth) of signal filter + * \param filter_size (int) number of filter taps to generate + * \param bandwidth (float) Loop bandwidth + */ + digital_fll_band_edge_cc(float samps_per_sym, float rolloff, + int filter_size, float bandwidth); + + /*! + * Design the band-edge filter based on the number of samples per symbol, + * filter rolloff factor, and the filter size + * + * \param samps_per_sym (float) Number of samples per symbol of signal + * \param rolloff (float) Rolloff factor of signal + * \param filter_size (int) Size (in taps) of the filter + */ + void design_filter(float samps_per_sym, float rolloff, int filter_size); + +public: + ~digital_fll_band_edge_cc (); + + /******************************************************************* + SET FUNCTIONS + *******************************************************************/ + + /*! + * \brief Set the number of samples per symbol + * + * Set's the number of samples per symbol the system should + * use. This value is uesd to calculate the filter taps and will + * force a recalculation. + * + * \param sps (float) new samples per symbol + * + */ + void set_samples_per_symbol(float sps); + + /*! + * \brief Set the rolloff factor of the shaping filter + * + * This sets the rolloff factor that is used in the pulse shaping + * filter and is used to calculate the filter taps. Changing this + * will force a recalculation of the filter taps. + * + * This should be the same value that is used in the transmitter's + * pulse shaping filter. It must be between 0 and 1 and is usually + * between 0.2 and 0.5 (where 0.22 and 0.35 are commonly used + * values). + * + * \param rolloff (float) new shaping filter rolloff factor [0,1] + * + */ + void set_rolloff(float rolloff); + + /*! + * \brief Set the number of taps in the filter + * + * This sets the number of taps in the band-edge filters. Setting + * this will force a recalculation of the filter taps. + * + * This should be about the same number of taps used in the + * transmitter's shaping filter and also not very large. A large + * number of taps will result in a large delay between input and + * frequency estimation, and so will not be as accurate. Between 30 + * and 70 taps is usual. + * + * \param filter_size (float) number of taps in the filters + * + */ + void set_filter_size(int filter_size); + + /******************************************************************* + GET FUNCTIONS + *******************************************************************/ + + /*! + * \brief Returns the number of sampler per symbol used for the filter + */ + float get_samples_per_symbol() const; + + /*! + * \brief Returns the rolloff factor used for the filter + */ + float get_rolloff() const; + + /*! + * \brief Returns the number of taps of the filter + */ + int get_filter_size() const; + + /*! + * Print the taps to screen. + */ + void print_taps(); + + int work (int noutput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items); +}; + +#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 + diff --git a/gr-digital/lib/digital_mpsk_receiver_cc.cc b/gr-digital/lib/digital_mpsk_receiver_cc.cc new file mode 100644 index 000000000..363b86c9f --- /dev/null +++ b/gr-digital/lib/digital_mpsk_receiver_cc.cc @@ -0,0 +1,316 @@ +/* -*- c++ -*- */ +/* + * Copyright 2005,2006,2007,2010,2011 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 <gr_io_signature.h> +#include <gr_prefs.h> +#include <digital_mpsk_receiver_cc.h> +#include <stdexcept> +#include <gr_math.h> +#include <gr_expj.h> +#include <gri_mmse_fir_interpolator_cc.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_mpsk_receiver_cc_sptr +digital_make_mpsk_receiver_cc(unsigned int M, float theta, + float loop_bw, + float fmin, float fmax, + float mu, float gain_mu, + float omega, float gain_omega, float omega_rel) +{ + return gnuradio::get_initial_sptr(new digital_mpsk_receiver_cc (M, theta, + loop_bw, + fmin, fmax, + mu, gain_mu, + omega, gain_omega, + omega_rel)); +} + +digital_mpsk_receiver_cc::digital_mpsk_receiver_cc (unsigned int M, float theta, + float loop_bw, + float fmin, float fmax, + float mu, float gain_mu, + float omega, float gain_omega, + float omega_rel) + : gr_block ("mpsk_receiver_cc", + gr_make_io_signature (1, 1, sizeof (gr_complex)), + gr_make_io_signature (1, 1, sizeof (gr_complex))), + gri_control_loop(loop_bw, fmax, fmin), + d_M(M), d_theta(theta), + d_current_const_point(0), + d_mu(mu), d_gain_mu(gain_mu), d_gain_omega(gain_omega), + d_omega_rel(omega_rel), d_max_omega(0), d_min_omega(0), + d_p_2T(0), d_p_1T(0), d_p_0T(0), d_c_2T(0), d_c_1T(0), d_c_0T(0) +{ + d_interp = new gri_mmse_fir_interpolator_cc(); + d_dl_idx = 0; + + set_omega(omega); + + if (omega <= 0.0) + throw std::out_of_range ("clock rate must be > 0"); + if (gain_mu < 0 || gain_omega < 0) + throw std::out_of_range ("Gains must be non-negative"); + + assert(d_interp->ntaps() <= DLLEN); + + // zero double length delay line. + for (unsigned int i = 0; i < 2 * DLLEN; i++) + d_dl[i] = gr_complex(0.0,0.0); + + // build the constellation vector from M + make_constellation(); + + // Select a phase detector and a decision maker for the modulation order + switch(d_M) { + case 2: // optimized algorithms for BPSK + d_phase_error_detector = &digital_mpsk_receiver_cc::phase_error_detector_bpsk; //bpsk; + d_decision = &digital_mpsk_receiver_cc::decision_bpsk; + break; + + case 4: // optimized algorithms for QPSK + d_phase_error_detector = &digital_mpsk_receiver_cc::phase_error_detector_qpsk; //qpsk; + d_decision = &digital_mpsk_receiver_cc::decision_qpsk; + break; + + default: // generic algorithms for any M (power of 2?) but not pretty + d_phase_error_detector = &digital_mpsk_receiver_cc::phase_error_detector_generic; + d_decision = &digital_mpsk_receiver_cc::decision_generic; + break; + } +} + +digital_mpsk_receiver_cc::~digital_mpsk_receiver_cc () +{ + delete d_interp; +} + +void +digital_mpsk_receiver_cc::forecast(int noutput_items, gr_vector_int &ninput_items_required) +{ + unsigned ninputs = ninput_items_required.size(); + for (unsigned i=0; i < ninputs; i++) + ninput_items_required[i] = (int) ceil((noutput_items * d_omega) + d_interp->ntaps()); +} + +// FIXME add these back in an test difference in performance +float +digital_mpsk_receiver_cc::phase_error_detector_qpsk(gr_complex sample) const +{ + float phase_error = 0; + if(fabsf(sample.real()) > fabsf(sample.imag())) { + if(sample.real() > 0) + phase_error = -sample.imag(); + else + phase_error = sample.imag(); + } + else { + if(sample.imag() > 0) + phase_error = sample.real(); + else + phase_error = -sample.real(); + } + + return phase_error; +} + +float +digital_mpsk_receiver_cc::phase_error_detector_bpsk(gr_complex sample) const +{ + return -(sample.real()*sample.imag()); +} + +float digital_mpsk_receiver_cc::phase_error_detector_generic(gr_complex sample) const +{ + //return gr_fast_atan2f(sample*conj(d_constellation[d_current_const_point])); + return -arg(sample*conj(d_constellation[d_current_const_point])); +} + +unsigned int +digital_mpsk_receiver_cc::decision_bpsk(gr_complex sample) const +{ + return (gr_branchless_binary_slicer(sample.real()) ^ 1); + //return gr_binary_slicer(sample.real()) ^ 1; +} + +unsigned int +digital_mpsk_receiver_cc::decision_qpsk(gr_complex sample) const +{ + unsigned int index; + + //index = gr_branchless_quad_0deg_slicer(sample); + index = gr_quad_0deg_slicer(sample); + return index; +} + +unsigned int +digital_mpsk_receiver_cc::decision_generic(gr_complex sample) const +{ + unsigned int min_m = 0; + float min_s = 65535; + + // Develop all possible constellation points and find the one that minimizes + // the Euclidean distance (error) with the sample + for(unsigned int m=0; m < d_M; m++) { + gr_complex diff = norm(d_constellation[m] - sample); + + if(fabs(diff.real()) < min_s) { + min_s = fabs(diff.real()); + min_m = m; + } + } + // Return the index of the constellation point that minimizes the error + return min_m; +} + + +void +digital_mpsk_receiver_cc::make_constellation() +{ + for(unsigned int m=0; m < d_M; m++) { + d_constellation.push_back(gr_expj((M_TWOPI/d_M)*m)); + } +} + +void +digital_mpsk_receiver_cc::mm_sampler(const gr_complex symbol) +{ + gr_complex sample, nco; + + d_mu--; // skip a number of symbols between sampling + d_phase += d_freq; // increment the phase based on the frequency of the rotation + + // Keep phase clamped and not walk to infinity + while(d_phase > M_TWOPI) + d_phase -= M_TWOPI; + while(d_phase < -M_TWOPI) + d_phase += M_TWOPI; + + nco = gr_expj(d_phase+d_theta); // get the NCO value for derotating the current sample + sample = nco*symbol; // get the downconverted symbol + + // Fill up the delay line for the interpolator + d_dl[d_dl_idx] = sample; + d_dl[(d_dl_idx + DLLEN)] = sample; // put this in the second half of the buffer for overflows + d_dl_idx = (d_dl_idx+1) % DLLEN; // Keep the delay line index in bounds +} + +void +digital_mpsk_receiver_cc::mm_error_tracking(gr_complex sample) +{ + gr_complex u, x, y; + float mm_error = 0; + + // Make sample timing corrections + + // set the delayed samples + d_p_2T = d_p_1T; + d_p_1T = d_p_0T; + d_p_0T = sample; + d_c_2T = d_c_1T; + d_c_1T = d_c_0T; + + d_current_const_point = (*this.*d_decision)(d_p_0T); // make a decision on the sample value + d_c_0T = d_constellation[d_current_const_point]; + + x = (d_c_0T - d_c_2T) * conj(d_p_1T); + y = (d_p_0T - d_p_2T) * conj(d_c_1T); + u = y - x; + mm_error = u.real(); // the error signal is in the real part + mm_error = gr_branchless_clip(mm_error, 1.0); // limit mm_val + + d_omega = d_omega + d_gain_omega * mm_error; // update omega based on loop error + d_omega = d_omega_mid + gr_branchless_clip(d_omega-d_omega_mid, d_omega_rel); // make sure we don't walk away + + d_mu += d_omega + d_gain_mu * mm_error; // update mu based on loop error + +#if VERBOSE_MM + printf("mm: mu: %f omega: %f mm_error: %f sample: %f+j%f constellation: %f+j%f\n", + d_mu, d_omega, mm_error, sample.real(), sample.imag(), + d_constellation[d_current_const_point].real(), d_constellation[d_current_const_point].imag()); +#endif +} + + +void +digital_mpsk_receiver_cc::phase_error_tracking(gr_complex sample) +{ + float phase_error = 0; + + // Make phase and frequency corrections based on sampled value + phase_error = (*this.*d_phase_error_detector)(sample); + + advance_loop(phase_error); + phase_wrap(); + frequency_limit(); + +#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[d_current_const_point].real(), d_constellation[d_current_const_point].imag()); +#endif +} + +int +digital_mpsk_receiver_cc::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]; + gr_complex *out = (gr_complex *) output_items[0]; + + int i=0, o=0; + + while((o < noutput_items) && (i < ninput_items[0])) { + while((d_mu > 1) && (i < ninput_items[0])) { + mm_sampler(in[i]); // puts symbols into a buffer and adjusts d_mu + i++; + } + + if(i < ninput_items[0]) { + gr_complex interp_sample = d_interp->interpolate(&d_dl[d_dl_idx], d_mu); + + mm_error_tracking(interp_sample); // corrects M&M sample time + phase_error_tracking(interp_sample); // corrects phase and frequency offsets + + out[o++] = interp_sample; + } + } + + #if 0 + printf("ninput_items: %d noutput_items: %d consuming: %d returning: %d\n", + ninput_items[0], noutput_items, i, o); + #endif + + consume_each(i); + return o; +} diff --git a/gr-digital/lib/digital_mpsk_receiver_cc.h b/gr-digital/lib/digital_mpsk_receiver_cc.h new file mode 100644 index 000000000..f8aa4e341 --- /dev/null +++ b/gr-digital/lib/digital_mpsk_receiver_cc.h @@ -0,0 +1,301 @@ +/* -*- c++ -*- */ +/* + * Copyright 2004,2007,2011 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_MPSK_RECEIVER_CC_H +#define INCLUDED_DIGITAL_MPSK_RECEIVER_CC_H + +#include <gruel/attributes.h> +#include <gri_control_loop.h> +#include <gr_block.h> +#include <gr_complex.h> +#include <fstream> + +class gri_mmse_fir_interpolator_cc; + +class digital_mpsk_receiver_cc; +typedef boost::shared_ptr<digital_mpsk_receiver_cc> digital_mpsk_receiver_cc_sptr; + +// public constructor +digital_mpsk_receiver_cc_sptr +digital_make_mpsk_receiver_cc (unsigned int M, float theta, + float loop_bw, + float fmin, float fmax, + float mu, float gain_mu, + float omega, float gain_omega, float omega_rel); + +/*! + * \brief This block takes care of receiving M-PSK modulated signals + * through phase, frequency, and symbol synchronization. + * \ingroup sync_blk + * \ingroup demod_blk + * + * This block takes care of receiving M-PSK modulated signals through + * phase, frequency, and symbol synchronization. It performs carrier + * frequency and phase locking as well as symbol timing recovery. It + * works with (D)BPSK, (D)QPSK, and (D)8PSK as tested currently. It + * should also work for OQPSK and PI/4 DQPSK. + * + * 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. There are optimized phase error + * detectors for BPSK and QPSK, but 8PSK is done using a brute-force + * computation of the constellation points to find the minimum. + * + * 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_mpsk_receiver_cc : public gr_block, public gri_control_loop +{ + public: + ~digital_mpsk_receiver_cc (); + 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); + + + // Member functions related to the symbol tracking portion of the receiver + //! (M&M) Returns current value of mu + float mu() const { return d_mu;} + + //! (M&M) Returns current value of omega + float omega() const { return d_omega;} + + //! (M&M) Returns mu gain factor + float gain_mu() const { return d_gain_mu;} + + //! (M&M) Returns omega gain factor + float gain_omega() const { return d_gain_omega;} + + //! (M&M) Sets value of mu + void set_mu (float mu) { d_mu = mu; } + + //! (M&M) Sets value of omega and its min and max values + void set_omega (float omega) { + d_omega = omega; + d_min_omega = omega*(1.0 - d_omega_rel); + d_max_omega = omega*(1.0 + d_omega_rel); + d_omega_mid = 0.5*(d_min_omega+d_max_omega); + } + + //! (M&M) Sets value for mu gain factor + void set_gain_mu (float gain_mu) { d_gain_mu = gain_mu; } + + //! (M&M) Sets value for omega gain factor + void set_gain_omega (float gain_omega) { d_gain_omega = gain_omega; } + +protected: + + /*! + * \brief Constructor to synchronize incoming M-PSK symbols + * + * \param M modulation order of the M-PSK modulation + * \param theta any constant phase rotation from the real axis of the constellation + * \param loop_bw Loop bandwidth to set gains of phase/freq tracking loop + * \param fmin minimum normalized frequency value the loop can achieve + * \param fmax maximum normalized frequency value the loop can achieve + * \param mu initial parameter for the interpolator [0,1] + * \param gain_mu gain parameter of the M&M error signal to adjust mu (~0.05) + * \param omega initial value for the number of symbols between samples (~number of samples/symbol) + * \param gain_omega gain parameter to adjust omega based on the error (~omega^2/4) + * \param omega_rel sets the maximum (omega*(1+omega_rel)) and minimum (omega*(1+omega_rel)) omega (~0.005) + * + * The constructor also chooses which phase detector and decision maker to use in the work loop based on the + * value of M. + */ + digital_mpsk_receiver_cc (unsigned int M, float theta, + float loop_bw, + float fmin, float fmax, + float mu, float gain_mu, + float omega, float gain_omega, float omega_rel); + + void make_constellation(); + void mm_sampler(const gr_complex symbol); + void mm_error_tracking(gr_complex sample); + void phase_error_tracking(gr_complex sample); + + + /*! + * \brief Phase error detector for MPSK modulations. + * + * \param sample the I&Q sample from which to determine the phase error + * + * This function determines the phase error for any MPSK signal by + * creating a set of PSK constellation points and doing a + * brute-force search to see which point minimizes the Euclidean + * distance. This point is then used to derotate the sample to the + * real-axis and a atan (using the fast approximation function) to + * determine the phase difference between the incoming sample and + * the real constellation point + * + * This should be cleaned up and made more efficient. + * + * \returns the approximated phase error. + */ + float phase_error_detector_generic(gr_complex sample) const; // generic for M but more costly + + /*! + * \brief Phase error detector for BPSK modulation. + * + * \param sample the I&Q sample from which to determine the phase error + * + * This function determines the phase error using a simple BPSK + * phase error detector by multiplying the real and imaginary (the + * error signal) components together. As the imaginary part goes to + * 0, so does this error. + * + * \returns the approximated phase error. + */ + float phase_error_detector_bpsk(gr_complex sample) const; // optimized for BPSK + + /*! + * \brief Phase error detector for QPSK modulation. + * + * \param sample the I&Q sample from which to determine the phase error + * + * This function determines the phase error using the limiter + * approach in a standard 4th order Costas loop + * + * \returns the approximated phase error. + */ + float phase_error_detector_qpsk(gr_complex sample) const; + + + + /*! + * \brief Decision maker for a generic MPSK constellation. + * + * \param sample the baseband I&Q sample from which to make the decision + * + * This decision maker is a generic implementation that does a + * brute-force search for the constellation point that minimizes the + * error between it and the incoming signal. + * + * \returns the index to d_constellation that minimizes the error/ + */ + unsigned int decision_generic(gr_complex sample) const; + + + /*! + * \brief Decision maker for BPSK constellation. + * + * \param sample the baseband I&Q sample from which to make the decision + * + * This decision maker is a simple slicer function that makes a + * decision on the symbol based on its placement on the real axis of + * greater than 0 or less than 0; the quadrature component is always + * 0. + * + * \returns the index to d_constellation that minimizes the error/ + */ + unsigned int decision_bpsk(gr_complex sample) const; + + + /*! + * \brief Decision maker for QPSK constellation. + * + * \param sample the baseband I&Q sample from which to make the decision + * + * This decision maker is a simple slicer function that makes a + * decision on the symbol based on its placement versus both axes + * and returns which quadrant the symbol is in. + * + * \returns the index to d_constellation that minimizes the error/ + */ + unsigned int decision_qpsk(gr_complex sample) const; + +private: + unsigned int d_M; + float d_theta; + + /*! + * \brief Decision maker function pointer + * + * \param sample the baseband I&Q sample from which to make the decision + * + * This is a function pointer that is set in the constructor to + * point to the proper decision function for the specified + * constellation order. + * + * \return index into d_constellation point that is the closest to the recieved sample + */ + unsigned int (digital_mpsk_receiver_cc::*d_decision)(gr_complex sample) const; // pointer to decision function + + + std::vector<gr_complex> d_constellation; + unsigned int d_current_const_point; + + // Members related to symbol timing + float d_mu, d_gain_mu; + float d_omega, d_gain_omega, d_omega_rel, d_max_omega, d_min_omega, d_omega_mid; + gr_complex d_p_2T, d_p_1T, d_p_0T; + gr_complex d_c_2T, d_c_1T, d_c_0T; + + /*! + * \brief Phase error detector function pointer + * + * \param sample the I&Q sample from which to determine the phase error + * + * This is a function pointer that is set in the constructor to + * point to the proper phase error detector function for the + * specified constellation order. + */ + float (digital_mpsk_receiver_cc::*d_phase_error_detector)(gr_complex sample) const; + + + //! get interpolated value + gri_mmse_fir_interpolator_cc *d_interp; + + //! delay line length. + static const unsigned int DLLEN = 8; + + //! delay line plus some length for overflow protection + __GR_ATTR_ALIGNED(8) gr_complex d_dl[2*DLLEN]; + + //! index to delay line + unsigned int d_dl_idx; + + friend digital_mpsk_receiver_cc_sptr + digital_make_mpsk_receiver_cc (unsigned int M, float theta, + float loop_bw, + float fmin, float fmax, + float mu, float gain_mu, + float omega, float gain_omega, float omega_rel); +}; + +#endif |