mirrors/gnss-sdr
1
0
Fork 0
mirror of https://github.com/gnss-sdr/gnss-sdr synced 2025-11-18 16:15:21 +00:00
Code Issues Releases Wiki Activity

feature: Adding code to fix coherent integration in GLONASS L1 C/A

Browse Source 
Debugs code to fix GLONASS coherent integration. Adds message handling
from telemetry decoding to signal tracking modules. Bug on poor track
performance stills need to be determine.
This commit is contained in:
Damian Miralles
2017-11-20 14:52:37 -07:00
parent 1c03579e61
commit 4a8182af26
6 changed files with 148 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
src/algorithms/telemetry_decoder/gnuradio_blocks/glonass_l1_ca_telemetry_decoder_cc.cc
View File

@@ -112,6 +112,7 @@ glonass_l1_ca_telemetry_decoder_cc::glonass_l1_ca_telemetry_decoder_cc(
d_flag_preamble = false;
d_channel = 0;
flag_TOW_set = false;
d_preamble_time_samples = 0;
}
@@ -274,6 +275,8 @@ int glonass_l1_ca_telemetry_decoder_cc::general_work (int noutput_items __attrib
LOG(INFO) << "Preamble detection for GLONASS L1 C/A SAT " << this->d_satellite;
// Enter into frame pre-detection status
d_stat = 1;
d_preamble_time_samples = d_symbol_history.at(0).Tracking_sample_counter; // record the preamble sample stamp
}
}
else if (d_stat == 1) // posible preamble lock
@@ -282,12 +285,17 @@ int glonass_l1_ca_telemetry_decoder_cc::general_work (int noutput_items __attrib
{
//check preamble separation
preamble_diff = d_sample_counter - d_preamble_index;
// Record the PRN start sample index associated to the preamble
d_preamble_time_samples = d_symbol_history.at(0).Tracking_sample_counter;
if (abs(preamble_diff - GLONASS_GNAV_PREAMBLE_PERIOD_SYMBOLS) == 0)
{
//try to decode frame
LOG(INFO) << "Starting string decoder for GLONASS L1 C/A SAT " << this->d_satellite;
d_preamble_index = d_sample_counter; //record the preamble sample stamp
d_stat = 2;
// send asynchronous message to tracking to inform of frame sync and extend correlation time
pmt::pmt_t value = pmt::from_double(static_cast<double>(d_preamble_time_samples) / static_cast<double>(d_symbol_history.at(0).fs) - 0.001);
this->message_port_pub(pmt::mp("preamble_timestamp_s"), value);
}
else
{

3
src/algorithms/telemetry_decoder/gnuradio_blocks/glonass_l1_ca_telemetry_decoder_cc.h
View File

@@ -79,6 +79,9 @@ private:
void decode_string(double *symbols, int frame_length);
//!< Help with coherent tracking
double d_preamble_time_samples;
//!< Preamble decoding
unsigned short int d_preambles_bits[GLONASS_GNAV_PREAMBLE_LENGTH_BITS];
int *d_preambles_symbols;

56
src/algorithms/tracking/gnuradio_blocks/glonass_l1_ca_dll_pll_c_aid_tracking_cc.cc
View File

@@ -215,6 +215,9 @@ glonass_l1_ca_dll_pll_c_aid_tracking_cc::glonass_l1_ca_dll_pll_c_aid_tracking_cc
d_code_error_filt_chips_s = 0.0;
d_carr_phase_error_secs_Ti = 0.0;
d_preamble_timestamp_s = 0.0;
d_carrier_frequency_hz = 0.0;
//set_min_output_buffer((long int)300);
}
@@ -263,10 +266,14 @@ void glonass_l1_ca_dll_pll_c_aid_tracking_cc::start_tracking()
d_acq_code_phase_samples = corrected_acq_phase_samples;
d_carrier_doppler_hz = d_acq_carrier_doppler_hz + d_if_freq + (DFRQ1_GLO * GLONASS_PRN.at(d_acquisition_gnss_synchro->PRN));
// d_carrier_doppler_hz = d_acq_carrier_doppler_hz + d_if_freq + (DFRQ1_GLO * GLONASS_PRN.at(d_acquisition_gnss_synchro->PRN));
// d_carrier_doppler_hz = d_acq_carrier_doppler_hz;
// d_carrier_phase_step_rad = GLONASS_TWO_PI * d_carrier_doppler_hz / static_cast<double>(d_fs_in);
d_carrier_frequency_hz = d_acq_carrier_doppler_hz + d_if_freq + (DFRQ1_GLO * GLONASS_PRN.at(d_acquisition_gnss_synchro->PRN));
d_carrier_doppler_hz = d_acq_carrier_doppler_hz;
d_carrier_phase_step_rad = GLONASS_TWO_PI * d_carrier_frequency_hz / static_cast<double>(d_fs_in);
d_carrier_phase_step_rad = GLONASS_TWO_PI * d_carrier_doppler_hz / static_cast<double>(d_fs_in);
// DLL/PLL filter initialization
d_carrier_loop_filter.initialize(d_acq_carrier_doppler_hz); // The carrier loop filter implements the Doppler accumulator
@@ -299,8 +306,8 @@ void glonass_l1_ca_dll_pll_c_aid_tracking_cc::start_tracking()
// enable tracking
d_pull_in = true;
d_enable_tracking = true;
d_enable_extended_integration = true;
d_preamble_synchronized = true;
d_enable_extended_integration = false;
d_preamble_synchronized = false;
LOG(INFO) << "PULL-IN Doppler [Hz]=" << d_carrier_doppler_hz
<< " Code Phase correction [samples]=" << delay_correction_samples
<< " PULL-IN Code Phase [samples]=" << d_acq_code_phase_samples;
@@ -309,14 +316,43 @@ void glonass_l1_ca_dll_pll_c_aid_tracking_cc::start_tracking()
glonass_l1_ca_dll_pll_c_aid_tracking_cc::~glonass_l1_ca_dll_pll_c_aid_tracking_cc()
{
d_dump_file.close();
if (d_dump_file.is_open())
{
try
{
d_dump_file.close();
}
catch(const std::exception & ex)
{
LOG(WARNING) << "Exception in destructor " << ex.what();
}
}
volk_gnsssdr_free(d_local_code_shift_chips);
volk_gnsssdr_free(d_correlator_outs);
volk_gnsssdr_free(d_ca_code);
if(d_dump)
{
if(d_channel == 0)
{
std::cout << "Writing .mat files ...";
}
//gps_l1_ca_dll_pll_c_aid_tracking_cc::save_matfile();
if(d_channel == 0)
{
std::cout << " done." << std::endl;
}
}
delete[] d_Prompt_buffer;
multicorrelator_cpu.free();
try
{
volk_gnsssdr_free(d_local_code_shift_chips);
volk_gnsssdr_free(d_correlator_outs);
volk_gnsssdr_free(d_ca_code);
delete[] d_Prompt_buffer;
multicorrelator_cpu.free();
}
catch(const std::exception & ex)
{
LOG(WARNING) << "Exception in destructor " << ex.what();
}
}

3
src/algorithms/tracking/gnuradio_blocks/glonass_l1_ca_dll_pll_c_aid_tracking_cc.h
View File

@@ -1,5 +1,5 @@
/*!
* \file glonass_l1_ca_dll_pll_tracking.h
* \file glonass_l1_ca_dll_pll_c_aid_tracking_cc.h
* \brief Interface of an adapter of a DLL+PLL tracking loop block
* for Glonass L1 C/A to a TrackingInterface
* \author Gabriel Araujo, 2017. gabriel.araujo.5000(at)gmail.com
@@ -157,6 +157,7 @@ private:
double d_code_freq_chips;
double d_code_phase_step_chips;
double d_carrier_doppler_hz;
double d_carrier_frequency_hz;
double d_carrier_phase_step_rad;
double d_acc_carrier_phase_cycles;
double d_code_phase_samples;

2
src/algorithms/tracking/gnuradio_blocks/glonass_l1_ca_dll_pll_tracking_cc.cc
View File

@@ -181,6 +181,8 @@ Glonass_L1_Ca_Dll_Pll_Tracking_cc::Glonass_L1_Ca_Dll_Pll_Tracking_cc(
d_code_phase_step_chips = 0.0;
d_carrier_phase_step_rad = 0.0;
d_glonass_freq_ch = 0;
set_relative_rate(1.0 / static_cast<double>(d_vector_length));
}