mirror of https://github.com/gnss-sdr/gnss-sdr
249 lines
8.0 KiB
C++
249 lines
8.0 KiB
C++
/*!
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* \file pcps_acquisition.h
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* \brief This class implements a Parallel Code Phase Search Acquisition
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*
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* Acquisition strategy (Kay Borre book + CFAR threshold).
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* <ol>
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* <li> Compute the input signal power estimation
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* <li> Doppler serial search loop
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* <li> Perform the FFT-based circular convolution (parallel time search)
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* <li> Record the maximum peak and the associated synchronization parameters
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* <li> Compute the test statistics and compare to the threshold
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* <li> Declare positive or negative acquisition using a message queue
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* </ol>
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*
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* Kay Borre book: K.Borre, D.M.Akos, N.Bertelsen, P.Rinder, and S.H.Jensen,
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* "A Software-Defined GPS and Galileo Receiver. A Single-Frequency
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* Approach", Birkhauser, 2007. pp 81-84
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*
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* \authors <ul>
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* <li> Javier Arribas, 2011. jarribas(at)cttc.es
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* <li> Luis Esteve, 2012. luis(at)epsilon-formacion.com
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* <li> Marc Molina, 2013. marc.molina.pena@gmail.com
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* <li> Cillian O'Driscoll, 2017. cillian(at)ieee.org
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* <li> Antonio Ramos, 2017. antonio.ramos@cttc.es
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* </ul>
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*
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* -------------------------------------------------------------------------
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*
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* Copyright (C) 2010-2018 (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 <https://www.gnu.org/licenses/>.
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*
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* -------------------------------------------------------------------------
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*/
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#ifndef GNSS_SDR_PCPS_ACQUISITION_H_
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#define GNSS_SDR_PCPS_ACQUISITION_H_
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#include "gnss_synchro.h"
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#include "acq_conf.h"
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#include <armadillo>
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#include <gnuradio/block.h>
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#include <gnuradio/fft/fft.h>
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#include <volk/volk.h>
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#include <string>
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class pcps_acquisition;
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typedef boost::shared_ptr<pcps_acquisition> pcps_acquisition_sptr;
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pcps_acquisition_sptr
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pcps_make_acquisition(const Acq_Conf& conf_);
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/*!
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* \brief This class implements a Parallel Code Phase Search Acquisition.
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*
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* Check \ref Navitec2012 "An Open Source Galileo E1 Software Receiver",
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* Algorithm 1, for a pseudocode description of this implementation.
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*/
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class pcps_acquisition : public gr::block
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{
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private:
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friend pcps_acquisition_sptr
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pcps_make_acquisition(const Acq_Conf& conf_);
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pcps_acquisition(const Acq_Conf& conf_);
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void update_local_carrier(gr_complex* carrier_vector, int32_t correlator_length_samples, float freq);
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void update_grid_doppler_wipeoffs();
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void update_grid_doppler_wipeoffs_step2();
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bool is_fdma();
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void acquisition_core(uint64_t samp_count);
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void send_negative_acquisition();
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void send_positive_acquisition();
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void dump_results(int32_t effective_fft_size);
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float first_vs_second_peak_statistic(uint32_t& indext, int32_t& doppler, uint32_t num_doppler_bins, int32_t doppler_max, int32_t doppler_step);
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float max_to_input_power_statistic(uint32_t& indext, int32_t& doppler, float input_power, uint32_t num_doppler_bins, int32_t doppler_max, int32_t doppler_step);
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bool start();
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Acq_Conf acq_parameters;
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bool d_active;
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bool d_worker_active;
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bool d_cshort;
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bool d_step_two;
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bool d_use_CFAR_algorithm_flag;
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int32_t d_positive_acq;
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float d_threshold;
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float d_mag;
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float d_input_power;
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float d_test_statistics;
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float* d_magnitude;
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float** d_magnitude_grid;
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float* d_tmp_buffer;
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gr_complex* d_input_signal;
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uint32_t d_samplesPerChip;
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int64_t d_old_freq;
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int32_t d_state;
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uint32_t d_channel;
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uint32_t d_doppler_step;
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float d_doppler_center_step_two;
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uint32_t d_num_noncoherent_integrations_counter;
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uint32_t d_fft_size;
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uint32_t d_consumed_samples;
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uint32_t d_num_doppler_bins;
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uint64_t d_sample_counter;
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gr_complex** d_grid_doppler_wipeoffs;
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gr_complex** d_grid_doppler_wipeoffs_step_two;
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gr_complex* d_fft_codes;
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gr_complex* d_data_buffer;
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lv_16sc_t* d_data_buffer_sc;
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gr::fft::fft_complex* d_fft_if;
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gr::fft::fft_complex* d_ifft;
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Gnss_Synchro* d_gnss_synchro;
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arma::fmat grid_;
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arma::fmat narrow_grid_;
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uint32_t d_num_doppler_bins_step2;
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int64_t d_dump_number;
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uint32_t d_dump_channel;
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uint32_t d_buffer_count;
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bool d_dump;
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std::string d_dump_filename;
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public:
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~pcps_acquisition();
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/*!
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* \brief Set acquisition/tracking common Gnss_Synchro object pointer
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* to exchange synchronization data between acquisition and tracking blocks.
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* \param p_gnss_synchro Satellite information shared by the processing blocks.
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*/
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inline void set_gnss_synchro(Gnss_Synchro* p_gnss_synchro)
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{
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gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
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d_gnss_synchro = p_gnss_synchro;
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}
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/*!
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* \brief Returns the maximum peak of grid search.
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*/
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inline uint32_t mag() const
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{
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return d_mag;
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}
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/*!
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* \brief Initializes acquisition algorithm and reserves memory.
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*/
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void init();
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/*!
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* \brief Sets local code for PCPS acquisition algorithm.
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* \param code - Pointer to the PRN code.
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*/
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void set_local_code(std::complex<float>* code);
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/*!
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* \brief Starts acquisition algorithm, turning from standby mode to
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* active mode
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* \param active - bool that activates/deactivates the block.
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*/
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inline void set_active(bool active)
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{
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gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
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d_active = active;
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}
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/*!
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* \brief If set to 1, ensures that acquisition starts at the
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* first available sample.
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* \param state - int=1 forces start of acquisition
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*/
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void set_state(int32_t state);
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/*!
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* \brief Set acquisition channel unique ID
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* \param channel - receiver channel.
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*/
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inline void set_channel(uint32_t channel)
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{
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gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
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d_channel = channel;
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}
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/*!
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* \brief Set statistics threshold of PCPS algorithm.
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* \param threshold - Threshold for signal detection (check \ref Navitec2012,
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* Algorithm 1, for a definition of this threshold).
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*/
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inline void set_threshold(float threshold)
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{
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gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
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d_threshold = threshold;
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}
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/*!
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* \brief Set maximum Doppler grid search
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* \param doppler_max - Maximum Doppler shift considered in the grid search [Hz].
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*/
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inline void set_doppler_max(uint32_t doppler_max)
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{
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gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
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acq_parameters.doppler_max = doppler_max;
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}
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/*!
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* \brief Set Doppler steps for the grid search
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* \param doppler_step - Frequency bin of the search grid [Hz].
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*/
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inline void set_doppler_step(uint32_t doppler_step)
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{
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gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
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d_doppler_step = doppler_step;
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}
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/*!
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* \brief Parallel Code Phase Search Acquisition signal processing.
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*/
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int general_work(int noutput_items, gr_vector_int& ninput_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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#endif /* GNSS_SDR_PCPS_ACQUISITION_H_*/
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