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Work in progress for GPS L2C support:

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- Patched GPS L2CM tracking pull-in code.
- Workaround for ViterbiDecoder bug
This commit is contained in:
Javier
2015-06-12 15:49:25 +02:00
parent 24c75a19db
commit adf73e0610
7 changed files with 116 additions and 127 deletions
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24
src/algorithms/tracking/gnuradio_blocks/gps_l2_m_dll_pll_tracking_cc.cc
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@@ -222,7 +222,8 @@ void gps_l2_m_dll_pll_tracking_cc::start_tracking()
corrected_acq_phase_samples = T_prn_mod_samples + corrected_acq_phase_samples;
}
delay_correction_samples = d_acq_code_phase_samples - corrected_acq_phase_samples;
d_acq_code_phase_samples = corrected_acq_phase_samples;
//TODO: debug the algorithm implementation and enable correction
//d_acq_code_phase_samples = corrected_acq_phase_samples;
d_carrier_doppler_hz = d_acq_carrier_doppler_hz;
@@ -247,7 +248,7 @@ void gps_l2_m_dll_pll_tracking_cc::start_tracking()
sys = sys_.substr(0,1);
// DEBUG OUTPUT
std::cout << "Tracking start on channel " << d_channel << " for satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << std::endl;
std::cout << "Tracking start on channel " << d_channel << " for satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) <<" whith Doppler="<<d_acq_carrier_doppler_hz<<" [Hz]"<< std::endl;
LOG(INFO) << "Starting tracking of satellite " << Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << " on channel " << d_channel;
@@ -336,10 +337,10 @@ int gps_l2_m_dll_pll_tracking_cc::general_work (int noutput_items, gr_vector_int
gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
{
// process vars
float carr_error_hz;
float carr_error_filt_hz;
float code_error_chips;
float code_error_filt_chips;
float carr_error_hz=0;
float carr_error_filt_hz=0;
float code_error_chips=0;
float code_error_filt_chips=0;
// GNSS_SYNCHRO OBJECT to interchange data between tracking->telemetry_decoder
Gnss_Synchro current_synchro_data = Gnss_Synchro();
@@ -358,12 +359,15 @@ int gps_l2_m_dll_pll_tracking_cc::general_work (int noutput_items, gr_vector_int
int acq_to_trk_delay_samples;
acq_to_trk_delay_samples = d_sample_counter - d_acq_sample_stamp;
acq_trk_shif_correction_samples = d_current_prn_length_samples - fmod(static_cast<float>(acq_to_trk_delay_samples), static_cast<float>(d_current_prn_length_samples));
samples_offset = round(d_acq_code_phase_samples + acq_trk_shif_correction_samples);
samples_offset = round(d_acq_code_phase_samples + acq_trk_shif_correction_samples+(1.5*(d_fs_in/GPS_L2_M_CODE_RATE_HZ)));
// /todo: Check if the sample counter sent to the next block as a time reference should be incremented AFTER sended or BEFORE
//d_sample_counter_seconds = d_sample_counter_seconds + (((double)samples_offset) / static_cast<double>(d_fs_in));
d_sample_counter = d_sample_counter + samples_offset; //count for the processed samples
d_pull_in = false;
//std::cout<<" samples_offset="<<samples_offset<<"\r\n";
//std::cout<<" d_acq_code_phase_samples="<<d_acq_code_phase_samples<<std::endl;
//std::cout<<" acq_trk_shif_correction_samples="<<acq_trk_shif_correction_samples<<std::endl;
//std::cout<<" d_current_prn_length_samples="<<d_current_prn_length_samples<<std::endl;
//std::cout<<" samples_offset="<<samples_offset<<std::endl;
// Fill the acquisition data
current_synchro_data = *d_acquisition_gnss_synchro;
current_synchro_data.Flag_valid_tracking = false;
@@ -522,7 +526,7 @@ int gps_l2_m_dll_pll_tracking_cc::general_work (int noutput_items, gr_vector_int
d_last_seg = floor(d_sample_counter / d_fs_in);
std::cout << "Current input signal time = " << d_last_seg << " [s]" << std::endl;
std::cout << "GPS L2C M Tracking CH " << d_channel << ": Satellite "
<< Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << ", CN0 = " << d_CN0_SNV_dB_Hz << " [dB-Hz]"<< std::endl;
<< Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN) << ", CN0 = " << d_CN0_SNV_dB_Hz << " [dB-Hz] "<<"Doppler="<<d_carrier_doppler_hz<<" [Hz]"<< std::endl;
//if (d_last_seg==5) d_carrier_lock_fail_counter=500; //DEBUG: force unlock!
}
}
@@ -533,7 +537,7 @@ int gps_l2_m_dll_pll_tracking_cc::general_work (int noutput_items, gr_vector_int
d_last_seg = floor(d_sample_counter / d_fs_in);
std::cout << "GPS L2C M Tracking CH " << d_channel << ": Satellite "
<< Gnss_Satellite(systemName[sys], d_acquisition_gnss_synchro->PRN)
<< ", CN0 = " << d_CN0_SNV_dB_Hz << " [dB-Hz]"<<std::endl;
<< ", CN0 = " << d_CN0_SNV_dB_Hz << " [dB-Hz] "<<"Doppler="<<d_carrier_doppler_hz<<" [Hz]"<< std::endl;
//std::cout<<"TRK CH "<<d_channel<<" Carrier_lock_test="<<d_carrier_lock_test<< std::endl;
}
}