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Code Issues Releases Wiki Activity

Trim CN0 smoother parameters. Add it to the FPGA block

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This commit is contained in:
Carles Fernandez 2019-04-25 15:30:11 +02:00
parent 42c0544c4c
commit 9d36199901
5 changed files with 23 additions and 11 deletions
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10
src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.cc
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@ -440,7 +440,10 @@ dll_pll_veml_tracking::dll_pll_veml_tracking(const Dll_Pll_Conf &conf_) : gr::bl
d_carrier_lock_threshold = trk_parameters.carrier_lock_th;
d_Prompt_Data = static_cast<gr_complex *>(volk_gnsssdr_malloc(sizeof(gr_complex), volk_gnsssdr_get_alignment()));
d_cn0_smoother = Exponential_Smoother();
if (d_code_period > 0.0)
{
d_cn0_smoother.set_samples_for_initialization(200 / static_cast<int>(d_code_period * 1000.0));
}
d_acquisition_gnss_synchro = nullptr;
d_channel = 0;
d_acq_code_phase_samples = 0.0;
@ -853,7 +856,7 @@ bool dll_pll_veml_tracking::cn0_and_tracking_lock_status(double coh_integration_
d_Prompt_buffer[d_cn0_estimation_counter % trk_parameters.cn0_samples] = d_P_accu;
d_cn0_estimation_counter++;
// Code lock indicator
double d_CN0_SNV_dB_Hz_raw = cn0_svn_estimator(d_Prompt_buffer, trk_parameters.cn0_samples, coh_integration_time_s);
float d_CN0_SNV_dB_Hz_raw = cn0_svn_estimator(d_Prompt_buffer, trk_parameters.cn0_samples, static_cast<float>(coh_integration_time_s));
d_CN0_SNV_dB_Hz = d_cn0_smoother.smooth(d_CN0_SNV_dB_Hz_raw);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, trk_parameters.cn0_samples);
@ -1593,11 +1596,12 @@ int dll_pll_veml_tracking::general_work(int noutput_items __attribute__((unused)
d_acc_carrier_phase_rad -= d_carrier_phase_step_rad * static_cast<double>(samples_offset);
d_state = 2;
d_sample_counter += samples_offset; // count for the processed samples
d_cn0_smoother.reset();
DLOG(INFO) << "Number of samples between Acquisition and Tracking = " << acq_trk_diff_samples << " ( " << acq_trk_diff_seconds << " s)";
DLOG(INFO) << "PULL-IN Doppler [Hz] = " << d_carrier_doppler_hz
<< ". PULL-IN Code Phase [samples] = " << d_acq_code_phase_samples;
d_cn0_smoother.reset();
consume_each(samples_offset); // shift input to perform alignment with local replica
return 0;
}

9
src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking_fpga.cc
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@ -350,6 +350,11 @@ dll_pll_veml_tracking_fpga::dll_pll_veml_tracking_fpga(const Dll_Pll_Conf_Fpga &
d_Prompt_buffer = new gr_complex[trk_parameters.cn0_samples];
d_carrier_lock_test = 1.0;
d_CN0_SNV_dB_Hz = 0.0;
d_cn0_smoother = Exponential_Smoother();
if (d_code_period > 0.0)
{
d_cn0_smoother.set_samples_for_initialization(200 / static_cast<int>(d_code_period * 1000.0));
}
d_carrier_lock_fail_counter = 0;
d_carrier_lock_threshold = trk_parameters.carrier_lock_th;
d_Prompt_Data = static_cast<gr_complex *>(volk_gnsssdr_malloc(sizeof(gr_complex), volk_gnsssdr_get_alignment()));
@ -582,7 +587,8 @@ bool dll_pll_veml_tracking_fpga::cn0_and_tracking_lock_status(double coh_integra
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, trk_parameters.cn0_samples, coh_integration_time_s);
float d_CN0_SNV_dB_Hz_raw = cn0_svn_estimator(d_Prompt_buffer, trk_parameters.cn0_samples, static_cast<float>(coh_integration_time_s));
d_CN0_SNV_dB_Hz = d_cn0_smoother.smooth(d_CN0_SNV_dB_Hz_raw);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, trk_parameters.cn0_samples);
// Loss of lock detection
@ -1437,6 +1443,7 @@ int dll_pll_veml_tracking_fpga::general_work(int noutput_items __attribute__((un
int32_t samples_offset = round(d_acq_code_phase_samples);
d_acc_carrier_phase_rad -= d_carrier_phase_step_rad * static_cast<double>(samples_offset);
d_state = 2;
d_cn0_smoother.reset();
// DEBUG OUTPUT
std::cout << "Tracking of " << systemName << " " << signal_pretty_name << " signal started on channel " << d_channel << " for satellite " << Gnss_Satellite(systemName, d_acquisition_gnss_synchro->PRN) << std::endl;

2
src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking_fpga.h
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@ -33,6 +33,7 @@
#define GNSS_SDR_DLL_PLL_VEML_TRACKING_FPGA_H
#include "dll_pll_conf_fpga.h"
#include "exponential_smoother.h"
#include "tracking_FLL_PLL_filter.h" // for PLL/FLL filter
#include "tracking_loop_filter.h" // for DLL filter
#include <boost/circular_buffer.hpp>
@ -201,6 +202,7 @@ private:
boost::circular_buffer<gr_complex> d_Prompt_circular_buffer;
//std::deque<gr_complex> d_Prompt_buffer_deque;
gr_complex *d_Prompt_buffer;
Exponential_Smoother d_cn0_smoother;
// file dump
std::ofstream d_dump_file;

9
src/algorithms/tracking/libs/exponential_smoother.cc
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@ -31,7 +31,6 @@
*/
#include "exponential_smoother.h"
#include <iostream> ///////////////
#include <iterator>
#include <numeric>
@ -40,11 +39,11 @@ Exponential_Smoother::Exponential_Smoother()
alpha_ = 0.001;
old_value_ = 0.0;
one_minus_alpha_ = 1.0 - alpha_;
samples_for_initialization_ = 500;
samples_for_initialization_ = 200;
initializing_ = true;
init_counter_ = 0;
min_value_ = 25;
offset_ = 9.0;
min_value_ = 25.0;
offset_ = 12.0;
init_buffer_.reserve(samples_for_initialization_);
}
@ -117,7 +116,7 @@ float Exponential_Smoother::smooth(float raw)
init_buffer_.push_back(smoothed_value);
if (init_counter_ == samples_for_initialization_)
{
old_value_ = std::accumulate(std::begin(init_buffer_), std::end(init_buffer_), 0.0) / static_cast<float>(init_buffer_.size());
old_value_ = std::accumulate(std::begin(init_buffer_), std::end(init_buffer_), 0.0f) / static_cast<float>(init_buffer_.size());
if (old_value_ < (min_value_ + offset_))
{
// flush buffer and start again

4
src/algorithms/tracking/libs/exponential_smoother.h
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@ -49,8 +49,8 @@ class Exponential_Smoother
public:
Exponential_Smoother(); //!< Constructor
~Exponential_Smoother(); //!< Destructor
void set_alpha(float alpha); //!< 0 < alpha < 1. The higher, the most responsive, but more variance. Default value: 0.0001
void set_samples_for_initialization(int num_samples); //!< Number of samples averaged for initialization. Default value:
void set_alpha(float alpha); //!< 0 < alpha < 1. The higher, the most responsive, but more variance. Default value: 0.001
void set_samples_for_initialization(int num_samples); //!< Number of samples averaged for initialization. Default value: 200
void reset();
void set_min_value(float value);
void set_offset(float offset);