diff options
Diffstat (limited to 'gr-digital/lib')
| -rw-r--r-- | gr-digital/lib/Makefile.am | 29 | ||||
| -rw-r--r-- | gr-digital/lib/digital_constellation_decoder_cb.cc | 77 | ||||
| -rw-r--r-- | gr-digital/lib/digital_constellation_decoder_cb.h | 64 | ||||
| -rw-r--r-- | gr-digital/lib/digital_constellation_receiver_cb.cc | 131 | ||||
| -rw-r--r-- | gr-digital/lib/digital_constellation_receiver_cb.h | 149 |
5 files changed, 438 insertions, 12 deletions
diff --git a/gr-digital/lib/Makefile.am b/gr-digital/lib/Makefile.am index 5d7fdecbf..560d242ad 100644 --- a/gr-digital/lib/Makefile.am +++ b/gr-digital/lib/Makefile.am @@ -24,22 +24,27 @@ include $(top_srcdir)/Makefile.common AM_CPPFLAGS = $(STD_DEFINES_AND_INCLUDES) $(PYTHON_CPPFLAGS) $(WITH_INCLUDES) # These headers get installed in ${prefix}/include/gnuradio -grinclude_HEADERS = \ - digital_constellation.h \ - digital_costas_loop_cc.h \ - digital_cma_equalizer_cc.h \ - digital_lms_dd_equalizer_cc.h \ - digital_kurtotic_equalizer_cc.h \ +grinclude_HEADERS = \ + digital_constellation.h \ + digital_constellation_receiver_cb.h \ + digital_constellation_decoder_cb.h \ + digital_costas_loop_cc.h \ + digital_cma_equalizer_cc.h \ + digital_lms_dd_equalizer_cc.h \ + digital_kurtotic_equalizer_cc.h \ digital_metric_type.h lib_LTLIBRARIES = libgnuradio-digital.la -libgnuradio_digital_la_SOURCES = \ - digital_constellation.cc \ - digital_costas_loop_cc.cc \ - digital_cma_equalizer_cc.cc \ - digital_lms_dd_equalizer_cc.cc \ - digital_kurtotic_equalizer_cc.cc +libgnuradio_digital_la_SOURCES = \ + digital_constellation.cc \ + digital_constellation_receiver_cb.h \ + digital_constellation_decoder_cb.h \ + digital_costas_loop_cc.cc \ + digital_cma_equalizer_cc.cc \ + digital_lms_dd_equalizer_cc.cc \ + digital_kurtotic_equalizer_cc.cc \ + digital_constellation_receiver_cb.h libgnuradio_digital_la_LIBADD = \ $(GNURADIO_CORE_LA) 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..8ac34f1d6 --- /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 digital_constellation_decoder_cb_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..420ae5c74 --- /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 + gr_make_constellation_decoder_cb (digital_constellation_sptr constellation); + + digital_constellation_decoder_cb (digital_constellation_sptr constellation); + + public: + + void forecast (int noutput_items, + gr_vector_int &ninput_items_required); + + int general_work (int noutput_items, + gr_vector_int &ninput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items); +}; + +#endif diff --git a/gr-digital/lib/digital_constellation_receiver_cb.cc b/gr-digital/lib/digital_constellation_receiver_cb.cc new file mode 100644 index 000000000..56385f11e --- /dev/null +++ b/gr-digital/lib/digital_constellation_receiver_cb.cc @@ -0,0 +1,131 @@ +/* -*- c++ -*- */ +/* + * Copyright 2011 Free Software Foundation, Inc. + * + * This file is part of GNU Radio + * + * GNU Radio is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3, or (at your option) + * any later version. + * + * GNU Radio is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU Radio; see the file COPYING. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, + * Boston, MA 02110-1301, USA. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <gr_io_signature.h> +#include <gr_prefs.h> +#include <digital_constellation_receiver_cb.h> +#include <stdexcept> +#include <gr_math.h> +#include <gr_expj.h> + + +#define M_TWOPI (2*M_PI) +#define VERBOSE_MM 0 // Used for debugging symbol timing loop +#define VERBOSE_COSTAS 0 // Used for debugging phase and frequency tracking + +// Public constructor + +digital_constellation_receiver_cb_sptr +digital_make_constellation_receiver_cb(digital_constellation_sptr constell, + float alpha, float beta, + float fmin, float fmax) +{ + return gnuradio::get_initial_sptr(new digital_constellation_receiver_cb (constell, + alpha, beta, + fmin, fmax)); +} + +static int ios[] = {sizeof(char), sizeof(float), sizeof(float), sizeof(float)}; +static std::vector<int> iosig(ios, ios+sizeof(ios)/sizeof(int)); +digital_constellation_receiver_cb::digital_constellation_receiver_cb (digital_constellation_sptr constellation, + float alpha, float beta, + float fmin, float fmax) + : gr_block ("constellation_receiver_cb", + gr_make_io_signature (1, 1, sizeof (gr_complex)), + gr_make_io_signaturev (1, 4, iosig)), + d_constellation(constellation), + d_alpha(alpha), d_beta(beta), d_freq(0), d_max_freq(fmax), d_min_freq(fmin), d_phase(0), + d_current_const_point(0) +{ + if (d_constellation->dimensionality() != 1) + throw std::runtime_error ("This receiver only works with constellations of dimension 1."); +} + +void +digital_constellation_receiver_cb::phase_error_tracking(float phase_error) +{ + d_freq += d_beta*phase_error; // adjust frequency based on error + d_phase += d_freq + d_alpha*phase_error; // adjust phase based on error + + // Make sure we stay within +-2pi + while(d_phase > M_TWOPI) + d_phase -= M_TWOPI; + while(d_phase < -M_TWOPI) + d_phase += M_TWOPI; + + // Limit the frequency range + d_freq = gr_branchless_clip(d_freq, d_max_freq); + +#if VERBOSE_COSTAS + printf("cl: phase_error: %f phase: %f freq: %f sample: %f+j%f constellation: %f+j%f\n", + phase_error, d_phase, d_freq, sample.real(), sample.imag(), + d_constellation->points()[d_current_const_point].real(), + d_constellation->points()[d_current_const_point].imag()); +#endif +} + +int +digital_constellation_receiver_cb::general_work (int noutput_items, + gr_vector_int &ninput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items) +{ + const gr_complex *in = (const gr_complex *) input_items[0]; + unsigned char *out = (unsigned char *) output_items[0]; + + int i=0; + + float phase_error; + unsigned int sym_value; + gr_complex sample, nco; + + float *out_err = 0, *out_phase = 0, *out_freq = 0; + if(output_items.size() == 4) { + out_err = (float *) output_items[1]; + out_phase = (float *) output_items[2]; + out_freq = (float *) output_items[3]; + } + + while((i < noutput_items) && (i < ninput_items[0])) { + sample = in[i]; + nco = gr_expj(d_phase); // get the NCO value for derotating the current sample + sample = nco*sample; // get the downconverted symbol + sym_value = d_constellation->decision_maker_pe(&sample, &phase_error); + // phase_error = -arg(sample*conj(d_constellation->points()[sym_value])); + phase_error_tracking(phase_error); // corrects phase and frequency offsets + out[i] = sym_value; + if(output_items.size() == 4) { + out_err[i] = phase_error; + out_phase[i] = d_phase; + out_freq[i] = d_freq; + } + i++; + } + + consume_each(i); + return i; +} + diff --git a/gr-digital/lib/digital_constellation_receiver_cb.h b/gr-digital/lib/digital_constellation_receiver_cb.h new file mode 100644 index 000000000..bf6fc51fa --- /dev/null +++ b/gr-digital/lib/digital_constellation_receiver_cb.h @@ -0,0 +1,149 @@ +/* -*- c++ -*- */ +/* + * Copyright 2011 Free Software Foundation, Inc. + * + * This file is part of GNU Radio + * + * GNU Radio is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3, or (at your option) + * any later version. + * + * GNU Radio is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU Radio; see the file COPYING. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, + * Boston, MA 02110-1301, USA. + */ + +#ifndef INCLUDED_DIGITAL_CONSTELLATION_RECEIVER_CB_H +#define INCLUDED_DIGITAL_CONSTELLATION_RECEIVER_CB_H + +#include <gr_block.h> +#include <digital_constellation.h> +#include <gr_complex.h> +#include <math.h> +#include <fstream> + +class digital_constellation_receiver_cb; +typedef boost::shared_ptr<digital_constellation_receiver_cb> digital_constellation_receiver_cb_sptr; + +// public constructor +digital_constellation_receiver_cb_sptr +digital_make_constellation_receiver_cb (digital_constellation_sptr constellation, + float alpha, float beta, + float fmin, float fmax); + +/*! + * \brief This block takes care of receiving generic modulated signals through phase, frequency, and symbol + * synchronization. + * \ingroup sync_blk + * \ingroup demod_blk + * + * This block takes care of receiving generic modulated signals through phase, frequency, and symbol + * synchronization. It performs carrier frequency and phase locking as well as symbol timing recovery. + * + * The phase and frequency synchronization are based on a Costas loop that finds the error of the incoming + * signal point compared to its nearest constellation point. The frequency and phase of the NCO are + * updated according to this error. + * + * The symbol synchronization is done using a modified Mueller and Muller circuit from the paper: + * + * G. R. Danesfahani, T.G. Jeans, "Optimisation of modified Mueller and Muller + * algorithm," Electronics Letters, Vol. 31, no. 13, 22 June 1995, pp. 1032 - 1033. + * + * This circuit interpolates the downconverted sample (using the NCO developed by the Costas loop) + * every mu samples, then it finds the sampling error based on this and the past symbols and the decision + * made on the samples. Like the phase error detector, there are optimized decision algorithms for BPSK + * and QPKS, but 8PSK uses another brute force computation against all possible symbols. The modifications + * to the M&M used here reduce self-noise. + * + */ + +class digital_constellation_receiver_cb : public gr_block +{ + public: + int general_work (int noutput_items, + gr_vector_int &ninput_items, + gr_vector_const_void_star &input_items, + gr_vector_void_star &output_items); + + + // Member function related to the phase/frequency tracking portion of the receiver + //! (CL) Returns the value for alpha (the phase gain term) + float alpha() const { return d_alpha; } + + //! (CL) Returns the value of beta (the frequency gain term) + float beta() const { return d_beta; } + + //! (CL) Returns the current value of the frequency of the NCO in the Costas loop + float freq() const { return d_freq; } + + //! (CL) Returns the current value of the phase of the NCO in the Costal loop + float phase() const { return d_phase; } + + //! (CL) Sets the value for alpha (the phase gain term) + void set_alpha(float alpha) { d_alpha = alpha; } + + //! (CL) Setss the value of beta (the frequency gain term) + void set_beta(float beta) { d_beta = beta; } + + //! (CL) Sets the current value of the frequency of the NCO in the Costas loop + void set_freq(float freq) { d_freq = freq; } + + //! (CL) Setss the current value of the phase of the NCO in the Costal loop + void set_phase(float phase) { d_phase = phase; } + + +protected: + + /*! + * \brief Constructor to synchronize incoming M-PSK symbols + * + * \param constellation constellation of points for generic modulation + * \param alpha gain parameter to adjust the phase in the Costas loop (~0.01) + * \param beta gain parameter to adjust the frequency in the Costas loop (~alpha^2/4) + * \param fmin minimum normalized frequency value the loop can achieve + * \param fmax maximum normalized frequency value the loop can achieve + * + * The constructor also chooses which phase detector and decision maker to use in the + * work loop based on the value of M. + */ + digital_constellation_receiver_cb (digital_constellation_sptr constellation, + float alpha, float beta, + float fmin, float fmax); + + void phase_error_tracking(float phase_error); + + private: + unsigned int d_M; + + // Members related to carrier and phase tracking + float d_alpha; + float d_beta; + float d_freq, d_max_freq, d_min_freq; + float d_phase; + + digital_constellation_sptr d_constellation; + unsigned int d_current_const_point; + + //! delay line length. + static const unsigned int DLLEN = 8; + + //! delay line plus some length for overflow protection + gr_complex d_dl[2*DLLEN] __attribute__ ((aligned(8))); + + //! index to delay line + unsigned int d_dl_idx; + + friend digital_constellation_receiver_cb_sptr + digital_make_constellation_receiver_cb (digital_constellation_sptr constell, + float alpha, float beta, + float fmin, float fmax); +}; + +#endif |