Trim CN0 smoother parameters. Add it to the FPGA block

src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.cc

@@ -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;
             }

src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking_fpga.cc

@@ -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;

src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking_fpga.h

@@ -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;

src/algorithms/tracking/libs/exponential_smoother.cc

@@ -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;
+    min_value_ = 25.0;
-    offset_ = 9.0;
+    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

src/algorithms/tracking/libs/exponential_smoother.h

@@ -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_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:
+    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);