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Code Issues Releases Wiki Activity

Bug fixes and Code refactoring in telemetry decoder

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This commit is contained in:
Javier Arribas
2017-01-26 16:09:49 +01:00
parent d64935406d
commit 3a11452a9e
5 changed files with 46 additions and 29 deletions
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50
src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l1_ca_telemetry_decoder_cc.cc
View File

@@ -110,6 +110,8 @@ gps_l1_ca_telemetry_decoder_cc::gps_l1_ca_telemetry_decoder_cc(
d_channel = 0;
Prn_timestamp_at_preamble_ms = 0.0;
flag_PLL_180_deg_phase_locked = false;
tmp_counter=0;
}
@@ -145,6 +147,7 @@ bool gps_l1_ca_telemetry_decoder_cc::gps_word_parityCheck(unsigned int gpsword)
int gps_l1_ca_telemetry_decoder_cc::general_work (int noutput_items __attribute__((unused)), gr_vector_int &ninput_items __attribute__((unused)),
gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
{
int corr_value = 0;
int preamble_diff_ms = 0;
@@ -182,7 +185,8 @@ int gps_l1_ca_telemetry_decoder_cc::general_work (int noutput_items __attribute_
d_preamble_time_seconds = in[0][0].Tracking_timestamp_secs; // record the preamble sample stamp
DLOG(INFO) << "Preamble detection for SAT " << this->d_satellite << "in[0][0].Tracking_timestamp_secs=" << round(in[0][0].Tracking_timestamp_secs * 1000.0);
//sync the symbol to bits integrator
d_symbol_accumulator = 0; d_symbol_accumulator_counter = 0;
d_symbol_accumulator = 0;
d_symbol_accumulator_counter = 0;
d_frame_bit_index = 0;
d_stat = 1; // enter into frame pre-detection status
}
@@ -331,25 +335,33 @@ int gps_l1_ca_telemetry_decoder_cc::general_work (int noutput_items __attribute_
//1. Copy the current tracking output
current_synchro_data = in[0][0];
//2. Add the telemetry decoder information
if (this->d_flag_preamble == true and d_GPS_FSM.d_nav.d_TOW > 0)
//update TOW at the preamble instant (todo: check for valid d_TOW)
// JAVI: 30/06/2014
// TOW, in GPS, is referred to the START of the SUBFRAME, that is, THE FIRST SYMBOL OF THAT SUBFRAME, NOT THE PREAMBLE.
// thus, no correction should be done. d_TOW_at_Preamble should be renamed to d_TOW_at_subframe_start.
// Sice we detected the preable, then, we are in the last symbol of that preamble, or just at the start of the first subframe symbol.
{
d_TOW_at_Preamble = d_GPS_FSM.d_nav.d_TOW + GPS_SUBFRAME_SECONDS; //we decoded the current TOW when the last word of the subframe arrive, so, we have a lag of ONE SUBFRAME
d_TOW_at_current_symbol = d_TOW_at_Preamble;
Prn_timestamp_at_preamble_ms = in[0][0].Tracking_timestamp_secs * 1000.0;
if (flag_TOW_set == false)
{
flag_TOW_set = true;
}
}
if (this->d_flag_preamble == true and d_GPS_FSM.d_nav.d_TOW > 0)
//update TOW at the preamble instant (todo: check for valid d_TOW)
// JAVI: 30/06/2014
// TOW, in GPS, is referred to the START of the SUBFRAME, that is, THE FIRST SYMBOL OF THAT SUBFRAME, NOT THE PREAMBLE.
// thus, no correction should be done. d_TOW_at_Preamble should be renamed to d_TOW_at_subframe_start.
// Sice we detected the preable, then, we are in the last symbol of that preamble, or just at the start of the first subframe symbol.
{
d_TOW_at_Preamble = d_GPS_FSM.d_nav.d_TOW;
Prn_timestamp_at_preamble_ms = in[0][0].Tracking_timestamp_secs * 1000.0;
//std::cout.precision(17);
//std::cout<<"symbol diff="<<tmp_counter<<" Preable TOW="<<std::fixed<<d_TOW_at_Preamble
// <<" with DeltaTOW="<<d_TOW_at_Preamble-d_TOW_at_current_symbol
// <<" decoded at "<<Prn_timestamp_at_preamble_ms/1000<<"[s]\r\n";
d_TOW_at_current_symbol = d_TOW_at_Preamble;
if (flag_TOW_set == false)
{
flag_TOW_set = true;
}
tmp_counter=0;
}
else
{
d_TOW_at_current_symbol = d_TOW_at_current_symbol + GPS_L1_CA_CODE_PERIOD;
}
{
tmp_counter++;
d_TOW_at_current_symbol = d_TOW_at_current_symbol + GPS_L1_CA_CODE_PERIOD;
}
current_synchro_data.d_TOW = d_TOW_at_Preamble;
current_synchro_data.d_TOW_at_current_symbol = d_TOW_at_current_symbol;

7
src/algorithms/telemetry_decoder/gnuradio_blocks/gps_l1_ca_telemetry_decoder_cc.h
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@@ -98,6 +98,9 @@ private:
double d_symbol_accumulator;
short int d_symbol_accumulator_counter;
//debug
int tmp_counter;
//bits and frame
unsigned short int d_frame_bit_index;
unsigned int d_GPS_frame_4bytes;
@@ -121,8 +124,8 @@ private:
double d_preamble_time_seconds;
double d_TOW_at_Preamble;
double d_TOW_at_current_symbol;
long double d_TOW_at_Preamble;
long double d_TOW_at_current_symbol;
double Prn_timestamp_at_preamble_ms;
bool flag_TOW_set;