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.
92 lines
2.5 KiB
C++
92 lines
2.5 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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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <gnuradio/io_signature.h>
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#include <gnuradio/expj.h>
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#include "correct_phase_from_tag_impl.h"
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namespace gr {
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namespace hamnet70 {
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correct_phase_from_tag::sptr
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correct_phase_from_tag::make(const std::string &phase_tag_name)
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{
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return gnuradio::get_initial_sptr
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(new correct_phase_from_tag_impl(phase_tag_name));
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}
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/*
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* The private constructor
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*/
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correct_phase_from_tag_impl::correct_phase_from_tag_impl(const std::string &phase_tag_name)
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: gr::sync_block("correct_phase_from_tag",
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gr::io_signature::make(1, 1, sizeof(gr_complex)),
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gr::io_signature::make(1, 1, sizeof(gr_complex))),
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m_pmtPhaseTagName(pmt::intern(phase_tag_name)),
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m_rotation(1, 0)
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{}
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/*
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* Our virtual destructor.
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*/
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correct_phase_from_tag_impl::~correct_phase_from_tag_impl()
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{
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}
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int
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correct_phase_from_tag_impl::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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const gr_complex *in = (const gr_complex *) input_items[0];
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gr_complex *out = (gr_complex *) output_items[0];
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std::vector<tag_t> tags;
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get_tags_in_window(tags, 0, 0, noutput_items, m_pmtPhaseTagName);
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size_t tagidx = 0;
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// rotate the data by the last set phase angle
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for(int i = 0; i < noutput_items; i++) {
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if((tagidx < tags.size()) && (tags[tagidx].offset == nitems_read(0) + i)) {
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double phase = pmt::to_double(tags[tagidx].value);
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m_rotation = gr_expj(-phase);
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tagidx++;
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}
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out[i] = in[i] * m_rotation;
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}
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for(size_t i = 0; i < tags.size(); i++) {
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}
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// Tell runtime system how many output items we produced.
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return noutput_items;
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}
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} /* namespace hamnet70 */
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} /* namespace gr */
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