diff options
| -rw-r--r-- | gnuradio-core/src/lib/general/Makefile.am | 3 | ||||
| -rw-r--r-- | gnuradio-core/src/lib/general/general.i | 2 | ||||
| -rw-r--r-- | gnuradio-core/src/lib/general/gri_control_loop.cc | 183 | ||||
| -rw-r--r-- | gnuradio-core/src/lib/general/gri_control_loop.h | 201 | ||||
| -rw-r--r-- | gnuradio-core/src/lib/general/gri_control_loop.i | 57 |
5 files changed, 446 insertions, 0 deletions
diff --git a/gnuradio-core/src/lib/general/Makefile.am b/gnuradio-core/src/lib/general/Makefile.am index 29f9d8d44..f210cee39 100644 --- a/gnuradio-core/src/lib/general/Makefile.am +++ b/gnuradio-core/src/lib/general/Makefile.am @@ -153,6 +153,7 @@ libgeneral_la_SOURCES = \ gr_wvps_ff.cc \ gri_add_const_ss_generic.cc \ gri_char_to_float.cc \ + gri_control_loop.cc \ gri_debugger_hook.cc \ gri_fft.cc \ gri_float_to_char.cc \ @@ -312,6 +313,7 @@ grinclude_HEADERS = \ gri_agc2_cc.h \ gri_agc2_ff.h \ gri_char_to_float.h \ + gri_control_loop.h \ gri_debugger_hook.h \ gri_fft.h \ gri_float_to_char.h \ @@ -460,6 +462,7 @@ swiginclude_HEADERS = \ gri_agc_ff.i \ gri_agc2_cc.i \ gri_agc2_ff.i \ + gri_control_loop.i \ gr_descrambler_bb.i \ gr_scrambler_bb.i \ gr_probe_mpsk_snr_c.i \ diff --git a/gnuradio-core/src/lib/general/general.i b/gnuradio-core/src/lib/general/general.i index 08b5ad98c..f9adff3fa 100644 --- a/gnuradio-core/src/lib/general/general.i +++ b/gnuradio-core/src/lib/general/general.i @@ -22,6 +22,7 @@ %{ +#include <gri_control_loop.h> #include <gr_nop.h> #include <gr_null_sink.h> #include <gr_null_source.h> @@ -138,6 +139,7 @@ #include <gr_burst_tagger.h> %} +%include "gri_control_loop.i" %include "gr_nop.i" %include "gr_null_sink.i" %include "gr_null_source.i" diff --git a/gnuradio-core/src/lib/general/gri_control_loop.cc b/gnuradio-core/src/lib/general/gri_control_loop.cc new file mode 100644 index 000000000..d84b47493 --- /dev/null +++ b/gnuradio-core/src/lib/general/gri_control_loop.cc @@ -0,0 +1,183 @@ +/* -*- 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. + */ + +#include <gri_control_loop.h> +#include <gr_math.h> +#include <stdexcept> + +#define M_TWOPI (2.0f*M_PI) + +gri_control_loop::gri_control_loop(float loop_bw, + float max_freq, float min_freq) + : d_phase(0), d_freq(0), d_max_freq(max_freq), d_min_freq(min_freq) +{ + // Set the damping factor for a critically damped system + d_damping = sqrtf(2.0f)/2.0f; + + // Set the bandwidth, which will then call update_gains() + set_loop_bandwidth(loop_bw); +} + +gri_control_loop::~gri_control_loop() +{ +} + +void +gri_control_loop::update_gains() +{ + float denom = (1.0 + 2.0*d_damping*d_loop_bw + d_loop_bw*d_loop_bw); + d_alpha = (4*d_damping*d_loop_bw) / denom; + d_beta = (4*d_loop_bw*d_loop_bw) / denom; +} + +void +gri_control_loop::advance_loop(float error) +{ + d_freq = d_freq + d_beta * error; + d_phase = d_phase + d_freq + d_alpha * error; +} + + +void +gri_control_loop::phase_wrap() +{ + while(d_phase>M_TWOPI) + d_phase -= M_TWOPI; + while(d_phase<-M_TWOPI) + d_phase += M_TWOPI; +} + +void +gri_control_loop::frequency_limit() +{ + if (d_freq > d_max_freq) + d_freq = d_min_freq; + else if (d_freq < d_min_freq) + d_freq = d_max_freq; +} + +/******************************************************************* + SET FUNCTIONS +*******************************************************************/ + +void +gri_control_loop::set_loop_bandwidth(float bw) +{ + if(bw < 0) { + throw std::out_of_range ("gri_control_loop: invalid bandwidth. Must be >= 0."); + } + + d_loop_bw = bw; + update_gains(); +} + +void +gri_control_loop::set_damping_factor(float df) +{ + if(df < 0 || df > 1.0) { + throw std::out_of_range ("gri_control_loop: invalid damping factor. Must be in [0,1]."); + } + + d_damping = df; + update_gains(); +} + +void +gri_control_loop::set_alpha(float alpha) +{ + if(alpha < 0 || alpha > 1.0) { + throw std::out_of_range ("gri_control_loop: invalid alpha. Must be in [0,1]."); + } + d_alpha = alpha; +} + +void +gri_control_loop::set_beta(float beta) +{ + if(beta < 0 || beta > 1.0) { + throw std::out_of_range ("gri_control_loop: invalid beta. Must be in [0,1]."); + } + d_beta = beta; +} + +void +gri_control_loop::set_frequency(float freq) +{ + if(freq > d_max_freq) + d_freq = d_min_freq; + else if(freq < d_min_freq) + d_freq = d_max_freq; + else + d_freq = freq; +} + +void +gri_control_loop::set_phase(float phase) +{ + d_phase = phase; + while(d_phase>M_TWOPI) + d_phase -= M_TWOPI; + while(d_phase<-M_TWOPI) + d_phase += M_TWOPI; +} + + +/******************************************************************* + GET FUNCTIONS +*******************************************************************/ + + +float +gri_control_loop::get_loop_bandwidth() const +{ + return d_loop_bw; +} + +float +gri_control_loop::get_damping_factor() const +{ + return d_damping; +} + +float +gri_control_loop::get_alpha() const +{ + return d_alpha; +} + +float +gri_control_loop::get_beta() const +{ + return d_beta; +} + +float +gri_control_loop::get_frequency() const +{ + return d_freq; +} + +float +gri_control_loop::get_phase() const +{ + return d_phase; +} diff --git a/gnuradio-core/src/lib/general/gri_control_loop.h b/gnuradio-core/src/lib/general/gri_control_loop.h new file mode 100644 index 000000000..a85625bbd --- /dev/null +++ b/gnuradio-core/src/lib/general/gri_control_loop.h @@ -0,0 +1,201 @@ +/* -*- 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 GRI_CONTROL_LOOP +#define GRI_CONTROL_LOOP + +class gri_control_loop +{ + protected: + float d_phase, d_freq; + float d_max_freq, d_min_freq; + float d_damping, d_loop_bw; + float d_alpha, d_beta; + + public: + gri_control_loop(float loop_bw, float max_freq, float min_freq); + virtual ~gri_control_loop(); + + /*! \brief update the system gains from the loop bandwidth and damping factor + * + * This function updates the system gains based on the loop + * bandwidth and damping factor of the system. + * These two factors can be set separately through their own + * set functions. + */ + void update_gains(); + + /*! \brief update the system gains from the loop bandwidth and damping factor + * + * This function updates the system gains based on the loop + * bandwidth and damping factor of the system. + * These two factors can be set separately through their own + * set functions. + */ + void advance_loop(float error); + + /*! \brief Keep the phase between -2pi and 2pi + * + * This function keeps the phase between -2pi and 2pi. If the phase + * is greater than 2pi by d, it wraps around to be -2pi+d; similarly if + * it is less than -2pi by d, it wraps around to 2pi-d. + * + * This function should be called after advance_loop to keep the phase + * in a good operating region. It is set as a separate method in case + * another way is desired as this is fairly heavy-handed. + */ + void phase_wrap(); + + /*! \brief Keep the frequency between d_min_freq and d_max_freq + * + * This function keeps the frequency between d_min_freq and d_max_freq. + * If the frequency is greater than d_max_freq, it is set to d_max_freq. + * If the frequency is less than d_min_freq, it is set to d_min_freq. + * + * This function should be called after advance_loop to keep the frequency + * in the specified region. It is set as a separate method in case + * another way is desired as this is fairly heavy-handed. + */ + void frequency_limit(); + + /******************************************************************* + SET FUNCTIONS + *******************************************************************/ + + /*! + * \brief Set the loop bandwidth + * + * Set the loop filter's bandwidth to \p bw. This should be between + * 2*pi/200 and 2*pi/100 (in rads/samp). It must also be a positive + * number. + * + * When a new damping factor is set, the gains, alpha and beta, of the loop + * are recalculated by a call to update_gains(). + * + * \param bw (float) new bandwidth + * + */ + void set_loop_bandwidth(float bw); + + /*! + * \brief Set the loop damping factor + * + * Set the loop filter's damping factor to \p df. The damping factor + * should be sqrt(2)/2.0 for critically damped systems. + * Set it to anything else only if you know what you are doing. It must + * be a number between 0 and 1. + * + * When a new damping factor is set, the gains, alpha and beta, of the loop + * are recalculated by a call to update_gains(). + * + * \param df (float) new damping factor + * + */ + void set_damping_factor(float df); + + /*! + * \brief Set the loop gain alpha + * + * Set's the loop filter's alpha gain parameter. + * + * This value should really only be set by adjusting the loop bandwidth + * and damping factor. + * + * \param alpha (float) new alpha gain + * + */ + void set_alpha(float alpha); + + /*! + * \brief Set the loop gain beta + * + * Set's the loop filter's beta gain parameter. + * + * This value should really only be set by adjusting the loop bandwidth + * and damping factor. + * + * \param beta (float) new beta gain + * + */ + void set_beta(float beta); + + /*! + * \brief Set the Costas loop's frequency. + * + * Set's the Costas Loop's frequency. While this is normally updated by the + * inner loop of the algorithm, it could be useful to manually initialize, + * set, or reset this under certain circumstances. + * + * \param freq (float) new frequency + * + */ + void set_frequency(float freq); + + /*! + * \brief Set the Costas loop's phase. + * + * Set's the Costas Loop's phase. While this is normally updated by the + * inner loop of the algorithm, it could be useful to manually initialize, + * set, or reset this under certain circumstances. + * + * \param phase (float) new phase + * + */ + void set_phase(float phase); + + + /******************************************************************* + GET FUNCTIONS + *******************************************************************/ + + /*! + * \brief Returns the loop bandwidth + */ + float get_loop_bandwidth() const; + + /*! + * \brief Returns the loop damping factor + */ + float get_damping_factor() const; + + /*! + * \brief Returns the loop gain alpha + */ + float get_alpha() const; + + /*! + * \brief Returns the loop gain beta + */ + float get_beta() const; + + /*! + * \brief Get the Costas loop's frequency estimate + */ + float get_frequency() const; + + /*! + * \brief Get the Costas loop's phase estimate + */ + float get_phase() const; +}; + +#endif /* GRI_CONTROL_LOOP */ diff --git a/gnuradio-core/src/lib/general/gri_control_loop.i b/gnuradio-core/src/lib/general/gri_control_loop.i new file mode 100644 index 000000000..67f8838cb --- /dev/null +++ b/gnuradio-core/src/lib/general/gri_control_loop.i @@ -0,0 +1,57 @@ +/* -*- 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. + */ + + +class gri_control_loop +{ + public: + gri_control_loop(float loop_bw, float max_freq, float min_freq); + virtual ~gri_control_loop(); + + void update_gains(); + void advance_loop(float error); + void phase_wrap(); + void frequency_limit(); + + /******************************************************************* + SET FUNCTIONS + *******************************************************************/ + + void set_loop_bandwidth(float bw); + void set_damping_factor(float df); + void set_alpha(float alpha); + void set_beta(float beta); + void set_frequency(float freq); + void set_phase(float phase); + + + /******************************************************************* + GET FUNCTIONS + *******************************************************************/ + + float get_loop_bandwidth() const; + float get_damping_factor() const; + float get_alpha() const; + float get_beta() const; + float get_frequency() const; + float get_phase() const; +}; |