Thomas Kolb
cd9784efb6
- correct_frequency: Correct frequency by averaging the phase drift on
the preamble
- freq_est_lr: Luise & Reggiannini frequency estimator
- pid_controller: a PID controller that takes error values at the input
and generates steering values at the output
The combination of freq_est_lr and PID controller can be used together
with an NCO (signal source) to create a closed control loop for
frequency offset compensation.
58 lines
1.7 KiB
C++
58 lines
1.7 KiB
C++
/* -*- c++ -*- */
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/*
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* Copyright 2019 Thomas Kolb.
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*
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* This is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3, or (at your option)
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* any later version.
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*
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* This software is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this software; see the file COPYING. If not, write to
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* the Free Software Foundation, Inc., 51 Franklin Street,
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* Boston, MA 02110-1301, USA.
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*/
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#ifndef INCLUDED_HAMNET70_CORRECT_FREQUENCY_IMPL_H
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#define INCLUDED_HAMNET70_CORRECT_FREQUENCY_IMPL_H
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#include <hamnet70/correct_frequency.h>
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namespace gr {
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namespace hamnet70 {
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class correct_frequency_impl : public correct_frequency
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{
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private:
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std::vector<gr_complex> d_symbols;
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gr_complex d_correctionVector;
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gr_complex d_correctionIncrement;
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float d_lastPhase;
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float d_filteredPhaseInc;
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float d_unwrapOffset;
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size_t d_preIdx;
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static const constexpr float c_phaseInc_alpha = 0.001f;
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public:
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correct_frequency_impl(const std::vector<gr_complex> &symbols);
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~correct_frequency_impl();
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// Where all the action really happens
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int work(int noutput_items,
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gr_vector_const_void_star &input_items,
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gr_vector_void_star &output_items);
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};
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} // namespace hamnet70
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} // namespace gr
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#endif /* INCLUDED_HAMNET70_CORRECT_FREQUENCY_IMPL_H */
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