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bds b1i: Adding geo satellites tracking and setting up structure for d2 nav decoding

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This commit is contained in:
Damian Miralles 2018-12-24 15:14:10 -06:00
parent 0c4b8b25f1
commit 7cdd2ee477
4 changed files with 67 additions and 24 deletions
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3
src/algorithms/telemetry_decoder/gnuradio_blocks/beidou_b1i_telemetry_decoder_cc.cc
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@ -136,6 +136,8 @@ beidou_b1i_telemetry_decoder_cc::beidou_b1i_telemetry_decoder_cc(
d_channel = 0;
flag_SOW_set = false;
}
@ -265,6 +267,7 @@ void beidou_b1i_telemetry_decoder_cc::decode_subframe(double *frame_symbols, int
if (d_nav.have_new_ephemeris() == true)
{
// get object for this SV (mandatory)
d_nav.i_satellite_PRN = d_satellite.get_PRN();
std::shared_ptr<Beidou_Dnav_Ephemeris> tmp_obj = std::make_shared<Beidou_Dnav_Ephemeris>(d_nav.get_ephemeris());
this->message_port_pub(pmt::mp("telemetry"), pmt::make_any(tmp_obj));
LOG(INFO) << "BEIDOU DNAV Ephemeris have been received in channel" << d_channel << " from satellite " << d_satellite;

84
src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.cc
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@ -98,7 +98,7 @@ dll_pll_veml_tracking::dll_pll_veml_tracking(const Dll_Pll_Conf &conf_) : gr::bl
d_code_chip_rate = 0.0;
d_secondary_code_length = 0U;
d_secondary_code_string = nullptr;
d_gps_l1ca_preambles_symbols = nullptr;
d_preambles_symbols = nullptr;
signal_type = std::string(trk_parameters.signal);
std::map<std::string, std::string> map_signal_pretty_name;
@ -134,7 +134,8 @@ dll_pll_veml_tracking::dll_pll_veml_tracking(const Dll_Pll_Conf &conf_) : gr::bl
uint16_t preambles_bits[GPS_CA_PREAMBLE_LENGTH_BITS] = GPS_PREAMBLE;
// preamble bits to sampled symbols
d_gps_l1ca_preambles_symbols = static_cast<int32_t *>(volk_gnsssdr_malloc(GPS_CA_PREAMBLE_LENGTH_SYMBOLS * sizeof(int32_t), volk_gnsssdr_get_alignment()));
d_preamble_length_symbols = GPS_CA_PREAMBLE_LENGTH_SYMBOLS;
d_preambles_symbols = static_cast<int32_t *>(volk_gnsssdr_malloc(GPS_CA_PREAMBLE_LENGTH_SYMBOLS * sizeof(int32_t), volk_gnsssdr_get_alignment()));
int32_t n = 0;
for (uint16_t preambles_bit : preambles_bits)
{
@ -142,11 +143,11 @@ dll_pll_veml_tracking::dll_pll_veml_tracking(const Dll_Pll_Conf &conf_) : gr::bl
{
if (preambles_bit == 1)
{
d_gps_l1ca_preambles_symbols[n] = 1;
d_preambles_symbols[n] = 1;
}
else
{
d_gps_l1ca_preambles_symbols[n] = -1;
d_preambles_symbols[n] = -1;
}
n++;
}
@ -278,19 +279,19 @@ dll_pll_veml_tracking::dll_pll_veml_tracking(const Dll_Pll_Conf &conf_) : gr::bl
systemName = "Beidou";
if (signal_type == "B1")
{
d_signal_carrier_freq = BEIDOU_B1I_FREQ_HZ;
d_code_period = BEIDOU_B1I_CODE_PERIOD;
d_code_chip_rate = BEIDOU_B1I_CODE_RATE_HZ;
d_code_length_chips = static_cast<unsigned int>(BEIDOU_B1I_CODE_LENGTH_CHIPS);
d_symbols_per_bit = BEIDOU_B1I_TELEMETRY_SYMBOLS_PER_BIT;
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_secondary = true;
trk_parameters.track_pilot = false;
interchange_iq = false;
d_secondary_code_length = static_cast<unsigned int>(BEIDOU_B1I_SECONDARY_CODE_LENGTH);
d_secondary_code_string = const_cast<std::string *>(&BEIDOU_B1I_SECONDARY_CODE_STR);
// GEO Satellites use different secondary code
d_signal_carrier_freq = BEIDOU_B1I_FREQ_HZ;
d_code_period = BEIDOU_B1I_CODE_PERIOD;
d_code_chip_rate = BEIDOU_B1I_CODE_RATE_HZ;
d_code_length_chips = static_cast<unsigned int>(BEIDOU_B1I_CODE_LENGTH_CHIPS);
d_symbols_per_bit = BEIDOU_B1I_TELEMETRY_SYMBOLS_PER_BIT;
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_secondary = true;
trk_parameters.track_pilot = false;
interchange_iq = false;
d_secondary_code_length = static_cast<unsigned int>(BEIDOU_B1I_SECONDARY_CODE_LENGTH);
d_secondary_code_string = const_cast<std::string *>(&BEIDOU_B1I_SECONDARY_CODE_STR);
}
else
{
@ -573,6 +574,42 @@ void dll_pll_veml_tracking::start_tracking()
else if (systemName == "Beidou" and signal_type == "B1")
{
beidou_b1i_code_gen_float(d_tracking_code, d_acquisition_gnss_synchro->PRN, 0);
// Update secondary code settings for geo satellites
if(d_acquisition_gnss_synchro->PRN > 0 and d_acquisition_gnss_synchro->PRN < 6)
{
d_symbols_per_bit = 2;
d_correlation_length_ms = 1;
d_code_samples_per_chip = 1;
d_secondary = false;
trk_parameters.track_pilot = false;
interchange_iq = false;
d_secondary_code_length = 0;
d_secondary_code_string = const_cast<std::string *>(&BEIDOU_B1I_D2_SECONDARY_CODE_STR);
// preamble bits to sampled symbols
d_preamble_length_symbols = 22;
d_preambles_symbols = static_cast<int32_t *>(volk_gnsssdr_malloc(22 * sizeof(int32_t), volk_gnsssdr_get_alignment()));
int32_t n = 0;
uint16_t preambles_bits[BEIDOU_B1I_PREAMBLE_LENGTH_BITS] = {1,1,1,0,0,0,1,0,0,1,0};
for (uint16_t preambles_bit : preambles_bits)
{
for (uint32_t j = 0; j < d_symbols_per_bit; j++)
{
if (preambles_bit == 1)
{
d_preambles_symbols[n] = 1;
}
else
{
d_preambles_symbols[n] = -1;
}
n++;
}
}
d_symbol_history.resize(22); // Change fixed buffer size
d_symbol_history.clear();
}
}
multicorrelator_cpu.set_local_code_and_taps(d_code_samples_per_chip * d_code_length_chips, d_tracking_code, d_local_code_shift_chips);
@ -621,7 +658,7 @@ dll_pll_veml_tracking::~dll_pll_veml_tracking()
{
if (signal_type == "1C")
{
volk_gnsssdr_free(d_gps_l1ca_preambles_symbols);
volk_gnsssdr_free(d_preambles_symbols);
}
if (d_dump_file.is_open())
@ -1470,21 +1507,21 @@ int dll_pll_veml_tracking::general_work(int noutput_items __attribute__((unused)
d_symbol_history.push_back(d_Prompt->real());
//******* preamble correlation ********
int32_t corr_value = 0;
if ((d_symbol_history.size() == GPS_CA_PREAMBLE_LENGTH_SYMBOLS)) // and (d_make_correlation or !d_flag_frame_sync))
if ((d_symbol_history.size() == d_preamble_length_symbols)) // and (d_make_correlation or !d_flag_frame_sync))
{
for (uint32_t i = 0; i < GPS_CA_PREAMBLE_LENGTH_SYMBOLS; i++)
for (uint32_t i = 0; i < d_preamble_length_symbols; i++)
{
if (d_symbol_history.at(i) < 0) // symbols clipping
{
corr_value -= d_gps_l1ca_preambles_symbols[i];
corr_value -= d_preambles_symbols[i];
}
else
{
corr_value += d_gps_l1ca_preambles_symbols[i];
corr_value += d_preambles_symbols[i];
}
}
}
if (corr_value == GPS_CA_PREAMBLE_LENGTH_SYMBOLS)
if (corr_value == d_preamble_length_symbols)
{
//std::cout << "Preamble detected at tracking!" << std::endl;
next_state = true;
@ -1533,6 +1570,7 @@ int dll_pll_veml_tracking::general_work(int noutput_items __attribute__((unused)
current_synchro_data.Prompt_Q = static_cast<double>((*d_Prompt).imag());
}
}
current_synchro_data.Code_phase_samples = d_rem_code_phase_samples;
current_synchro_data.Carrier_phase_rads = d_acc_carrier_phase_rad;
current_synchro_data.Carrier_Doppler_hz = d_carrier_doppler_hz;

3
src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.h
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@ -107,7 +107,8 @@ private:
std::string *d_secondary_code_string;
std::string signal_pretty_name;
int32_t *d_gps_l1ca_preambles_symbols;
int32_t *d_preambles_symbols;
int32_t d_preamble_length_symbols;
boost::circular_buffer<float> d_symbol_history;
//tracking state machine

1
src/core/system_parameters/Beidou_B1I.h
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@ -56,6 +56,7 @@ const double BEIDOU_B1I_CHIP_PERIOD = 4.8875e-07; //!< beidou b1I c
const int BEIDOU_B1I_SECONDARY_CODE_LENGTH = 20;
const std::string BEIDOU_B1I_SECONDARY_CODE = "00000100110101001110";
const std::string BEIDOU_B1I_SECONDARY_CODE_STR = "00000100110101001110";
const std::string BEIDOU_B1I_D2_SECONDARY_CODE_STR = "00";
/*!
* \brief Maximum Time-Of-Arrival (TOA) difference between satellites for a receiver operated on Earth surface is 20 ms