mirror of https://github.com/gnss-sdr/gnss-sdr
232 lines
6.9 KiB
C++
232 lines
6.9 KiB
C++
/*!
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* \file pcps_acquisition_fine_doppler_cc.h
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* \brief This class implements a Parallel Code Phase Search Acquisition with multi-dwells and fine Doppler estimation
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* for GPS L1 C/A signal
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*
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* Acquisition strategy (Kay Borre book).
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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 port
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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, 2013. jarribas(at)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) 2010-2019 (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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* SPDX-License-Identifier: GPL-3.0-or-later
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*
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* -------------------------------------------------------------------------
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*/
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#ifndef GNSS_SDR_PCPS_ACQUISITION_FINE_DOPPLER_CC_H
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#define GNSS_SDR_PCPS_ACQUISITION_FINE_DOPPLER_CC_H
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#if ARMA_NO_BOUND_CHECKING
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#define ARMA_NO_DEBUG 1
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#endif
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#include "acq_conf.h"
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#include "channel_fsm.h"
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#include "gnss_synchro.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 <gnuradio/gr_complex.h>
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#include <volk_gnsssdr/volk_gnsssdr_alloc.h> // for volk_gnsssdr::vector
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#include <cstdint>
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#include <fstream>
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#include <memory>
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#include <string>
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#include <utility>
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class pcps_acquisition_fine_doppler_cc;
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using pcps_acquisition_fine_doppler_cc_sptr = boost::shared_ptr<pcps_acquisition_fine_doppler_cc>;
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pcps_acquisition_fine_doppler_cc_sptr pcps_make_acquisition_fine_doppler_cc(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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*/
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class pcps_acquisition_fine_doppler_cc : public gr::block
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{
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public:
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/*!
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* \brief Default destructor.
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*/
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~pcps_acquisition_fine_doppler_cc() = default;
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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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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 unsigned int mag() const
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{
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return d_test_statistics;
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}
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/*!
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* \brief Initializes acquisition algorithm.
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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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d_active = active;
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}
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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(unsigned int channel)
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{
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d_channel = channel;
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d_dump_channel = d_channel;
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}
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/*!
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* \brief Set channel fsm associated to this acquisition instance
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*/
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inline void set_channel_fsm(std::weak_ptr<ChannelFsm> channel_fsm)
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{
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d_channel_fsm = std::move(channel_fsm);
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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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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(unsigned int doppler_max)
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{
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d_config_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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void set_doppler_step(unsigned int doppler_step);
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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(int state);
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/*!
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* \brief Obtains the next power of 2 greater or equal to the input parameter
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* \param n - Integer value to obtain the next power of 2.
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*/
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unsigned int nextPowerOf2(unsigned int n);
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void dump_results(int effective_fft_size);
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void forecast(int noutput_items, gr_vector_int& ninput_items_required);
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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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private:
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friend pcps_acquisition_fine_doppler_cc_sptr pcps_make_acquisition_fine_doppler_cc(const Acq_Conf& conf_);
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explicit pcps_acquisition_fine_doppler_cc(const Acq_Conf& conf_);
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int compute_and_accumulate_grid(gr_vector_const_void_star& input_items);
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int estimate_Doppler();
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float estimate_input_power(gr_vector_const_void_star& input_items);
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double compute_CAF();
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void reset_grid();
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void update_carrier_wipeoff();
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bool start();
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Acq_Conf acq_parameters;
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int64_t d_fs_in;
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int d_samples_per_ms;
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int d_max_dwells;
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int d_gnuradio_forecast_samples;
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float d_threshold;
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std::string d_satellite_str;
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int d_config_doppler_max;
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int d_num_doppler_points;
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int d_doppler_step;
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unsigned int d_fft_size;
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uint64_t d_sample_counter;
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volk_gnsssdr::vector<gr_complex> d_fft_codes;
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volk_gnsssdr::vector<gr_complex> d_10_ms_buffer;
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volk_gnsssdr::vector<float> d_magnitude;
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volk_gnsssdr::vector<volk_gnsssdr::vector<float>> d_grid_data;
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volk_gnsssdr::vector<volk_gnsssdr::vector<std::complex<float>>> d_grid_doppler_wipeoffs;
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std::shared_ptr<gr::fft::fft_complex> d_fft_if;
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std::shared_ptr<gr::fft::fft_complex> d_ifft;
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Gnss_Synchro* d_gnss_synchro;
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unsigned int d_code_phase;
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float d_doppler_freq;
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float d_test_statistics;
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int d_positive_acq;
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int d_state;
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bool d_active;
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int d_well_count;
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int d_n_samples_in_buffer;
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bool d_dump;
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unsigned int d_channel;
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std::weak_ptr<ChannelFsm> d_channel_fsm;
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std::string d_dump_filename;
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arma::fmat grid_;
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int64_t d_dump_number;
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unsigned int d_dump_channel;
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};
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#endif /* pcps_acquisition_fine_doppler_cc*/
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