mirror of
https://github.com/gnss-sdr/gnss-sdr
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81 lines
3.0 KiB
C++
81 lines
3.0 KiB
C++
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/*!
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* \file notch_lite_cc.cc
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* \brief Implements a multi state notch filter algorithm
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* \author Antonio Ramos (antonio.ramosdet(at)gmail.com)
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*
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* -------------------------------------------------------------------------
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*
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* Copyright (C) 2010-2017 (see AUTHORS file for a list of contributors)
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*
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* GNSS-SDR is a software defined Global Navigation
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* Satellite Systems receiver
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*
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* This file is part of GNSS-SDR.
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*
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* GNSS-SDR 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 of the License, or
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* (at your option) any later version.
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*
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* GNSS-SDR 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 GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
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*
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* -------------------------------------------------------------------------
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*/
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#include "notch_lite_cc.h"
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#include <cmath>
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#include <complex>
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#include <cstdio>
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#include <cstring>
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#include <gnuradio/io_signature.h>
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#include <volk/volk.h>
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#include <iostream>
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#include <glog/logging.h>
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using google::LogMessage;
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notch_lite_sptr make_notch_filter_lite(float p_c_factor)
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{
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return notch_lite_sptr(new NotchLite(p_c_factor));
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}
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NotchLite::NotchLite(float p_c_factor) : gr::block("NotchLite",
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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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{
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const int alignment_multiple = volk_get_alignment() / sizeof(gr_complex);
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set_alignment(std::max(1, alignment_multiple));
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set_history(2);
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this->p_c_factor = gr_complex(p_c_factor , 0);
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z_0 = gr_complex(0 , 0);
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last_out = gr_complex(0,0);
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}
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int NotchLite::general_work(int noutput_items __attribute__((unused)), gr_vector_int &ninput_items __attribute__((unused)),
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gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
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{
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gr_complex* in = (gr_complex *) input_items[0];
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gr_complex* out = (gr_complex *) output_items[0];
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c_samples = static_cast<gr_complex *>(volk_malloc(noutput_items * sizeof(gr_complex), volk_get_alignment()));
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angle_ = static_cast<float *>(volk_malloc(noutput_items * sizeof(float), volk_get_alignment()));
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volk_32fc_x2_multiply_conjugate_32fc(c_samples, (in + 1), in, noutput_items);
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volk_32fc_s32f_atan2_32f(angle_, c_samples, ((float)1.0), noutput_items);
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for (int aux = 0; aux < noutput_items; aux++)
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{
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z_0 = std::exp(gr_complex(0,1) * (*(angle_ + aux)));
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*(out + aux) = *(in + aux + 1) - z_0 * (*(in + aux)) + p_c_factor * z_0 * last_out;
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last_out = *(out + aux);
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}
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volk_free(c_samples);
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volk_free(angle_);
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consume_each(noutput_items);
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return noutput_items;
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}
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