mirrors/gnss-sdr
1
0
Fork 0
mirror of https://github.com/gnss-sdr/gnss-sdr synced 2025-10-31 23:33:03 +00:00
Code Issues Releases Wiki Activity

Use PRS to determine code rollover boundary

Browse Source
This commit is contained in:
Cillian O'Driscoll
2015-11-18 14:40:05 +00:00
parent e8248d449d
commit fe33f9e0e2
1 changed files with 28 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

32
src/algorithms/tracking/gnuradio_blocks/galileo_e1_prs_de_tracking_cc.cc
View File

@@ -744,6 +744,18 @@ int galileo_e1_prs_de_tracking_cc::general_work (int noutput_items,gr_vector_int
d_rem_subcarrier_phase_samples_prs = rem_subcarrier_phase_cycles_prs*
static_cast<double>(d_fs_in)/Galileo_E1_A_SUB_CARRIER_RATE_HZ;
double e1b_code_length_prs_chips = Galileo_E1_B_CODE_LENGTH_CHIPS /
Galileo_E1_CODE_CHIP_RATE_HZ * Galileo_E1_A_CODE_CHIP_RATE_HZ;
double rem_code_phase_chips_prs = e1b_code_length_prs_chips -
std::fmod( d_code_phase_chips_prs, e1b_code_length_prs_chips );
if( rem_code_phase_chips_prs > e1b_code_length_prs_chips / 2.0 )
{
rem_code_phase_chips_prs = ( rem_code_phase_chips_prs - e1b_code_length_prs_chips );
}
d_rem_code_phase_samples_prs = rem_code_phase_chips_prs * d_fs_in/Galileo_E1_A_CODE_CHIP_RATE_HZ;
d_rem_carr_phase_rad_prs = d_rem_carr_phase_rad_prs + GPS_TWO_PI * d_carrier_doppler_hz_prs * T;
d_rem_carr_phase_rad_prs = fmod(d_rem_carr_phase_rad_prs, GPS_TWO_PI);
@@ -934,10 +946,22 @@ int galileo_e1_prs_de_tracking_cc::general_work (int noutput_items,gr_vector_int
double T_sc_prn_samples;
double K_sc_samples;
// Compute the next buffer lenght based in the new period of the PRN sequence and the code phase error estimation
T_chip_seconds = 1 / static_cast<double>(d_code_freq_chips);
T_prn_seconds = T_chip_seconds * Galileo_E1_B_CODE_LENGTH_CHIPS;
T_prn_samples = T_prn_seconds * static_cast<double>(d_fs_in);
K_blk_samples = T_prn_samples + d_rem_code_phase_samples; // + code_error_filt_secs * static_cast<double>(d_fs_in);
if( d_prs_tracking_enabled )
{
T_chip_seconds = 1 / static_cast<double>(d_code_freq_chips_prs);
T_prn_seconds = T_chip_seconds * Galileo_E1_B_CODE_LENGTH_CHIPS *
Galileo_E1_A_CODE_CHIP_RATE_HZ/Galileo_E1_CODE_CHIP_RATE_HZ;
T_prn_samples = T_prn_seconds * static_cast<double>(d_fs_in);
K_blk_samples = T_prn_samples + d_rem_code_phase_samples_prs; // + code_error_filt_secs * static_cast<double>(d_fs_in);
}
else
{
T_chip_seconds = 1 / static_cast<double>(d_code_freq_chips);
T_prn_seconds = T_chip_seconds * Galileo_E1_B_CODE_LENGTH_CHIPS;
T_prn_samples = T_prn_seconds * static_cast<double>(d_fs_in);
K_blk_samples = T_prn_samples + d_rem_code_phase_samples; // + code_error_filt_secs * static_cast<double>(d_fs_in);
}
T_sc_seconds = 1 / static_cast<double>(d_subcarrier_freq_cycles);
// THere is one subcarrier period per code chip: