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Fixing the round problem 

git-svn-id: https://svn.code.sf.net/p/gnss-sdr/code/trunk@96 64b25241-fba3-4117-9849-534c7e92360d
This commit is contained in:
Carles Fernandez 2011-12-24 22:45:14 +00:00
parent 181596a55e
commit 7aa58ef590
2 changed files with 30 additions and 6 deletions
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32
src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_tracking_cc.cc
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@ -38,7 +38,9 @@
#include "tracking_discriminators.h"
#include "CN_estimators.h"
#include "GPS_L1_CA.h"
#ifdef GNSS_SDR_USE_BOOST_ROUND
#include <boost/math/special_functions/round.hpp>
#endif
#include "control_message_factory.h"
#include <boost/lexical_cast.hpp>
#include <iostream>
@ -159,7 +161,13 @@ void gps_l1_ca_dll_pll_tracking_cc::start_tracking(){
T_chip_mod_seconds=1/d_code_freq_hz;
T_prn_mod_seconds=T_chip_mod_seconds*GPS_L1_CA_CODE_LENGTH_CHIPS;
T_prn_mod_samples=T_prn_mod_seconds*(float)d_fs_in;
d_next_prn_length_samples=round(T_prn_mod_samples);
#ifdef GNSS_SDR_USE_BOOST_ROUND
d_next_prn_length_samples=round(T_prn_mod_samples);
#else
d_next_prn_length_samples=std::round(T_prn_mod_samples);
#endif
float T_prn_true_seconds = GPS_L1_CA_CODE_LENGTH_CHIPS/GPS_L1_CA_CODE_RATE_HZ;
@ -220,6 +228,7 @@ void gps_l1_ca_dll_pll_tracking_cc::update_local_code()
tcode_chips=-rem_code_phase_chips;
for (int i=0;i<d_current_prn_length_samples;i++)
{
#ifdef GNSS_SDR_USE_BOOST_ROUND
associated_chip_index=1+round(fmod(tcode_chips-d_early_late_spc_chips,code_length_chips));
d_early_code[i] = d_ca_code[associated_chip_index];
associated_chip_index = 1+round(fmod(tcode_chips, code_length_chips));
@ -227,6 +236,15 @@ void gps_l1_ca_dll_pll_tracking_cc::update_local_code()
associated_chip_index = 1+round(fmod(tcode_chips+d_early_late_spc_chips, code_length_chips));
d_late_code[i] = d_ca_code[associated_chip_index];
tcode_chips=tcode_chips+d_code_phase_step_chips;
#else
associated_chip_index=1+std::round(fmod(tcode_chips-d_early_late_spc_chips,code_length_chips));
d_early_code[i] = d_ca_code[associated_chip_index];
associated_chip_index = 1+std::round(fmod(tcode_chips, code_length_chips));
d_prompt_code[i] = d_ca_code[associated_chip_index];
associated_chip_index = 1+std::round(fmod(tcode_chips+d_early_late_spc_chips, code_length_chips));
d_late_code[i] = d_ca_code[associated_chip_index];
tcode_chips=tcode_chips+d_code_phase_step_chips;
#endif
}
}
@ -292,8 +310,11 @@ int gps_l1_ca_dll_pll_tracking_cc::general_work (int noutput_items, gr_vector_in
acq_to_trk_delay_samples=d_sample_counter-d_acq_sample_stamp;
acq_trk_shif_correction_samples=d_next_prn_length_samples-fmod((float)acq_to_trk_delay_samples,(float)d_next_prn_length_samples);
//std::cout<<"acq_trk_shif_correction="<<acq_trk_shif_correction_samples<<"\r\n";
#ifdef GNSS_SDR_USE_BOOST_ROUND
samples_offset=round(d_acq_code_phase_samples+acq_trk_shif_correction_samples);
#else
samples_offset=std::round(d_acq_code_phase_samples+acq_trk_shif_correction_samples);
#endif
// /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)/(double)d_fs_in);
d_sample_counter=d_sample_counter+samples_offset; //count for the processed samples
@ -376,8 +397,11 @@ int gps_l1_ca_dll_pll_tracking_cc::general_work (int noutput_items, gr_vector_in
}
d_code_phase_samples=fmod(d_code_phase_samples,T_prn_true_samples);
#ifdef GNSS_SDR_USE_BOOST_ROUND
d_next_prn_length_samples=round(K_blk_samples); //round to a discrete samples
#else
d_next_prn_length_samples=std::round(K_blk_samples); //round to a discrete samples
#endif
d_next_rem_code_phase_samples=K_blk_samples-d_next_prn_length_samples; //rounding error
/*!

4
src/algorithms/tracking/gnuradio_blocks/jamfile.jam
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@ -1,4 +1,4 @@
project : build-dir ../../../../build ;
obj gps_l1_ca_dll_pll_tracking_cc : gps_l1_ca_dll_pll_tracking_cc.cc ;
obj gps_l1_ca_dll_fll_pll_tracking_cc : gps_l1_ca_dll_fll_pll_tracking_cc.cc ;
obj gps_l1_ca_dll_pll_tracking_cc : gps_l1_ca_dll_pll_tracking_cc.cc : <toolset>darwin:<define>GNSS_SDR_USE_BOOST_ROUND ;
obj gps_l1_ca_dll_fll_pll_tracking_cc : gps_l1_ca_dll_fll_pll_tracking_cc.cc : <toolset>darwin:<define>GNSS_SDR_USE_BOOST_ROUND ;