Add option to enable/disable carrier aiding in the code loop (enabled by default)

src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.cc

@@ -991,7 +991,11 @@ void dll_pll_veml_tracking::run_dll_pll()
     // Code discriminator filter
     d_code_error_filt_chips = d_code_loop_filter.apply(d_code_error_chips);  // [chips/second]
     // New code Doppler frequency estimation
-    d_code_freq_chips = (1.0 + (d_carrier_doppler_hz / d_signal_carrier_freq)) * d_code_chip_rate - d_code_error_filt_chips;
+    d_code_freq_chips = d_code_chip_rate - d_code_error_filt_chips;
+    if (trk_parameters.carrier_aiding)
+        {
+            d_code_freq_chips += d_carrier_doppler_hz * d_code_chip_rate / d_signal_carrier_freq;
+        }
 
     // Experimental: detect Carrier Doppler vs. Code Doppler incoherence and correct the Carrier Doppler
     if (trk_parameters.enable_doppler_correction == true)

src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking_fpga.cc

@@ -738,7 +738,11 @@ void dll_pll_veml_tracking_fpga::run_dll_pll()
     // Code discriminator filter
     d_code_error_filt_chips = d_code_loop_filter.apply(d_code_error_chips);  // [chips/second]
     // New code Doppler frequency estimation
-    d_code_freq_chips = (1.0 + (d_carrier_doppler_hz / d_signal_carrier_freq)) * d_code_chip_rate - d_code_error_filt_chips;
+    d_code_freq_chips = d_code_chip_rate - d_code_error_filt_chips;
+    if (trk_parameters.carrier_aiding)
+        {
+            d_code_freq_chips += d_carrier_doppler_hz * d_code_chip_rate / d_signal_carrier_freq;
+        }
 
     // Experimental: detect Carrier Doppler vs. Code Doppler incoherence and correct the Carrier Doppler
     if (trk_parameters.enable_doppler_correction == true)

src/algorithms/tracking/libs/dll_pll_conf.cc

@@ -55,6 +55,7 @@ Dll_Pll_Conf::Dll_Pll_Conf()
     slope = 1.0;
     spc = 0.5;
     y_intercept = 1.0;
+    carrier_aiding = true;
     extend_correlation_symbols = 1;
     cn0_samples = FLAGS_cn0_samples;
     cn0_smoother_samples = 200;
@@ -152,6 +153,7 @@ void Dll_Pll_Conf::SetFromConfiguration(ConfigurationInterface *configuration,
     max_code_lock_fail = configuration->property(role + ".max_lock_fail", max_code_lock_fail);
     max_carrier_lock_fail = configuration->property(role + ".max_carrier_lock_fail", max_carrier_lock_fail);
     carrier_lock_th = configuration->property(role + ".carrier_lock_th", carrier_lock_th);
+    carrier_aiding = configuration->property(role + ".carrier_aiding", carrier_aiding);
 
     // tracking lock tests smoother parameters
     cn0_smoother_samples = configuration->property(role + ".cn0_smoother_samples", cn0_smoother_samples);

src/algorithms/tracking/libs/dll_pll_conf.h

@@ -60,6 +60,7 @@ public:
     float spc;
     float y_intercept;
     int32_t extend_correlation_symbols;
+    bool carrier_aiding;
     bool high_dyn;
     std::string item_type;
     int32_t cn0_samples;

src/algorithms/tracking/libs/dll_pll_conf_fpga.cc

@@ -56,6 +56,7 @@ Dll_Pll_Conf_Fpga::Dll_Pll_Conf_Fpga()
     slope = 1.0;
     spc = 0.5;
     y_intercept = 1.0;
+    carrier_aiding = true;
     extend_correlation_symbols = 1;
     cn0_samples = FLAGS_cn0_samples;
     cn0_smoother_samples = 200;
@@ -157,6 +158,7 @@ void Dll_Pll_Conf_Fpga::SetFromConfiguration(ConfigurationInterface *configurati
     very_early_late_space_narrow_chips = configuration->property(role + ".very_early_late_space_narrow_chips", very_early_late_space_narrow_chips);
     extend_correlation_symbols = configuration->property(role + ".extend_correlation_symbols", extend_correlation_symbols);
     cn0_samples = configuration->property(role + ".cn0_samples", cn0_samples);
+    carrier_aiding = configuration->property(role + ".carrier_aiding", carrier_aiding);
 
     // tracking lock tests smoother parameters
     cn0_smoother_samples = configuration->property(role + ".cn0_smoother_samples", cn0_smoother_samples);

src/algorithms/tracking/libs/dll_pll_conf_fpga.h

@@ -63,6 +63,7 @@ public:
     float spc;
     float y_intercept;
     int32_t extend_correlation_symbols;
+    bool carrier_aiding;
     bool high_dyn;
     int32_t cn0_samples;
     int32_t cn0_min;