/*!
* \file pcps_acquisition.h
* \brief This class implements a Parallel Code Phase Search Acquisition
*
* Acquisition strategy (Kay Borre book + CFAR threshold).
*
* - Compute the input signal power estimation
*
- Doppler serial search loop
*
- Perform the FFT-based circular convolution (parallel time search)
*
- Record the maximum peak and the associated synchronization parameters
*
- Compute the test statistics and compare to the threshold
*
- Declare positive or negative acquisition using a message queue
*
*
* Kay Borre book: K.Borre, D.M.Akos, N.Bertelsen, P.Rinder, and S.H.Jensen,
* "A Software-Defined GPS and Galileo Receiver. A Single-Frequency
* Approach", Birkhauser, 2007. pp 81-84
*
* \authors
* - Javier Arribas, 2011. jarribas(at)cttc.es
*
- Luis Esteve, 2012. luis(at)epsilon-formacion.com
*
- Marc Molina, 2013. marc.molina.pena@gmail.com
*
- Cillian O'Driscoll, 2017. cillian(at)ieee.org
*
- Antonio Ramos, 2017. antonio.ramos@cttc.es
*
*
* -----------------------------------------------------------------------------
*
* Copyright (C) 2010-2020 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
*
* This file is part of GNSS-SDR.
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
* -----------------------------------------------------------------------------
*/
#ifndef GNSS_SDR_PCPS_ACQUISITION_H
#define GNSS_SDR_PCPS_ACQUISITION_H
#if ARMA_NO_BOUND_CHECKING
#define ARMA_NO_DEBUG 1
#endif
#include "acq_conf.h"
#include "channel_fsm.h"
#include
#include
#include
#include
#include // for gr_complex
#include // for scoped_lock
#include // for gr_vector_const_void_star
#include // for lv_16sc_t
#include // for volk_gnsssdr::vector
#include
#include
#include
#include
#include
#if HAS_STD_SPAN
#include
namespace own = std;
#else
#include
namespace own = gsl;
#endif
#if GNURADIO_USES_STD_POINTERS
#else
#include
#endif
class Gnss_Synchro;
class pcps_acquisition;
#if GNURADIO_USES_STD_POINTERS
using pcps_acquisition_sptr = std::shared_ptr;
#else
using pcps_acquisition_sptr = boost::shared_ptr;
#endif
pcps_acquisition_sptr pcps_make_acquisition(const Acq_Conf& conf_);
/*!
* \brief This class implements a Parallel Code Phase Search Acquisition.
*
* Check \ref Navitec2012 "An Open Source Galileo E1 Software Receiver",
* Algorithm 1, for a pseudocode description of this implementation.
*/
class pcps_acquisition : public gr::block
{
public:
~pcps_acquisition() = default;
/*!
* \brief Initializes acquisition algorithm and reserves memory.
*/
void init();
/*!
* \brief Set acquisition/tracking common Gnss_Synchro object pointer
* to exchange synchronization data between acquisition and tracking blocks.
* \param p_gnss_synchro Satellite information shared by the processing blocks.
*/
inline void set_gnss_synchro(Gnss_Synchro* p_gnss_synchro)
{
gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
d_gnss_synchro = p_gnss_synchro;
}
/*!
* \brief Sets local code for PCPS acquisition algorithm.
* \param code - Pointer to the PRN code.
*/
void set_local_code(std::complex* code);
/*!
* \brief If set to 1, ensures that acquisition starts at the
* first available sample.
* \param state - int=1 forces start of acquisition
*/
void set_state(int32_t state);
void set_resampler_latency(uint32_t latency_samples);
/*!
* \brief Returns the maximum peak of grid search.
*/
inline uint32_t mag() const
{
return d_mag;
}
/*!
* \brief Starts acquisition algorithm, turning from standby mode to
* active mode
* \param active - bool that activates/deactivates the block.
*/
inline void set_active(bool active)
{
gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
d_active = active;
}
/*!
* \brief Set acquisition channel unique ID
* \param channel - receiver channel.
*/
inline void set_channel(uint32_t channel)
{
d_channel = channel;
}
/*!
* \brief Set channel fsm associated to this acquisition instance
*/
inline void set_channel_fsm(std::weak_ptr channel_fsm)
{
d_channel_fsm = std::move(channel_fsm);
}
/*!
* \brief Set statistics threshold of PCPS algorithm.
* \param threshold - Threshold for signal detection (check \ref Navitec2012,
* Algorithm 1, for a definition of this threshold).
*/
inline void set_threshold(float threshold)
{
gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
d_threshold = threshold;
}
/*!
* \brief Set maximum Doppler grid search
* \param doppler_max - Maximum Doppler shift considered in the grid search [Hz].
*/
inline void set_doppler_max(uint32_t doppler_max)
{
gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
d_acq_parameters.doppler_max = doppler_max;
}
/*!
* \brief Set Doppler steps for the grid search
* \param doppler_step - Frequency bin of the search grid [Hz].
*/
inline void set_doppler_step(uint32_t doppler_step)
{
gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
d_doppler_step = doppler_step;
}
/*!
* \brief Set Doppler center frequency for the grid search. It will refresh the Doppler grid.
* \param doppler_center - Frequency center of the search grid [Hz].
*/
inline void set_doppler_center(int32_t doppler_center)
{
gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
if (doppler_center != d_doppler_center)
{
DLOG(INFO) << " Doppler assistance for Channel: " << d_channel << " => Doppler: " << doppler_center << "[Hz]";
d_doppler_center = doppler_center;
update_grid_doppler_wipeoffs();
}
}
/*!
* \brief Parallel Code Phase Search Acquisition signal processing.
*/
int general_work(int noutput_items, gr_vector_int& ninput_items,
gr_vector_const_void_star& input_items,
gr_vector_void_star& output_items);
private:
friend pcps_acquisition_sptr pcps_make_acquisition(const Acq_Conf& conf_);
explicit pcps_acquisition(const Acq_Conf& conf_);
void update_local_carrier(own::span carrier_vector, float freq);
void update_grid_doppler_wipeoffs();
void update_grid_doppler_wipeoffs_step2();
void acquisition_core(uint64_t samp_count);
void send_negative_acquisition();
void send_positive_acquisition();
void dump_results(int32_t effective_fft_size);
bool is_fdma();
bool start();
void calculate_threshold(void);
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);
float max_to_input_power_statistic(uint32_t& indext, int32_t& doppler, uint32_t num_doppler_bins, int32_t doppler_max, int32_t doppler_step);
volk_gnsssdr::vector> d_magnitude_grid;
volk_gnsssdr::vector d_tmp_buffer;
volk_gnsssdr::vector> d_input_signal;
volk_gnsssdr::vector>> d_grid_doppler_wipeoffs;
volk_gnsssdr::vector>> d_grid_doppler_wipeoffs_step_two;
volk_gnsssdr::vector> d_fft_codes;
volk_gnsssdr::vector> d_data_buffer;
volk_gnsssdr::vector d_data_buffer_sc;
std::unique_ptr d_fft_if;
std::unique_ptr d_ifft;
std::weak_ptr d_channel_fsm;
Acq_Conf d_acq_parameters;
Gnss_Synchro* d_gnss_synchro;
arma::fmat d_grid;
arma::fmat d_narrow_grid;
std::string d_dump_filename;
int64_t d_dump_number;
uint64_t d_sample_counter;
float d_threshold;
float d_mag;
float d_input_power;
float d_test_statistics;
float d_doppler_center_step_two;
int32_t d_state;
int32_t d_positive_acq;
int32_t d_doppler_center;
int32_t d_doppler_bias;
uint32_t d_channel;
uint32_t d_samplesPerChip;
uint32_t d_doppler_step;
uint32_t d_num_noncoherent_integrations_counter;
uint32_t d_fft_size;
uint32_t d_consumed_samples;
uint32_t d_num_doppler_bins;
uint32_t d_num_doppler_bins_step2;
uint32_t d_dump_channel;
uint32_t d_buffer_count;
bool d_active;
bool d_worker_active;
bool d_cshort;
bool d_step_two;
bool d_use_CFAR_algorithm_flag;
bool d_dump;
};
#endif // GNSS_SDR_PCPS_ACQUISITION_H