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Improve C/N0 estimation

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This commit is contained in:
Carles Fernandez 2018-04-09 21:09:25 +02:00
parent 204aef99d0
commit 0dac9489d5
16 changed files with 28 additions and 27 deletions
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8
src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.cc
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@ -606,7 +606,7 @@ bool dll_pll_veml_tracking::acquire_secondary()
}
bool dll_pll_veml_tracking::cn0_and_tracking_lock_status()
bool dll_pll_veml_tracking::cn0_and_tracking_lock_status(double coh_integration_time_s)
{
// ####### CN0 ESTIMATION AND LOCK DETECTORS ######
if (d_cn0_estimation_counter < FLAGS_cn0_samples)
@ -620,7 +620,7 @@ bool dll_pll_veml_tracking::cn0_and_tracking_lock_status()
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, static_cast<long>(trk_parameters.fs_in), static_cast<double>(d_code_length_chips));
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, coh_integration_time_s);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, FLAGS_cn0_samples);
// Loss of lock detection
@ -1233,7 +1233,7 @@ int dll_pll_veml_tracking::general_work(int noutput_items __attribute__((unused)
d_L_accu = *d_Late;
// Check lock status
if (!cn0_and_tracking_lock_status())
if (!cn0_and_tracking_lock_status(static_cast<double>(d_correlation_length_ms) * 1000.0))
{
clear_tracking_vars();
d_state = 0; // loss-of-lock detected
@ -1411,7 +1411,7 @@ int dll_pll_veml_tracking::general_work(int noutput_items __attribute__((unused)
save_correlation_results();
// check lock status
if (!cn0_and_tracking_lock_status())
if (!cn0_and_tracking_lock_status(static_cast<double>(d_correlation_length_ms) * 1000.0 * static_cast<double>(trk_parameters.extend_correlation_symbols)))
{
clear_tracking_vars();
d_state = 0; // loss-of-lock detected

2
src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.h
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@ -88,7 +88,7 @@ private:
dll_pll_veml_tracking(dllpllconf_t conf_);
bool cn0_and_tracking_lock_status();
bool cn0_and_tracking_lock_status(double coh_integration_time_s);
bool acquire_secondary();
void do_correlation_step(const gr_complex *input_samples);
void run_dll_pll();

2
src/algorithms/tracking/gnuradio_blocks/galileo_e1_tcp_connector_tracking_cc.cc
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@ -381,7 +381,7 @@ int Galileo_E1_Tcp_Connector_Tracking_cc::general_work(int noutput_items __attri
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, d_fs_in, Galileo_E1_B_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, Galileo_E1_CODE_PERIOD);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, FLAGS_cn0_samples);

2
src/algorithms/tracking/gnuradio_blocks/glonass_l1_ca_dll_pll_c_aid_tracking_cc.cc
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@ -762,7 +762,7 @@ int glonass_l1_ca_dll_pll_c_aid_tracking_cc::general_work(int noutput_items __at
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, d_fs_in, GLONASS_L1_CA_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, GLONASS_L1_CA_CODE_PERIOD);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES);
// Loss of lock detection

2
src/algorithms/tracking/gnuradio_blocks/glonass_l1_ca_dll_pll_c_aid_tracking_sc.cc
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@ -753,7 +753,7 @@ int glonass_l1_ca_dll_pll_c_aid_tracking_sc::general_work(int noutput_items __at
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, d_fs_in, GLONASS_L1_CA_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, GLONASS_L1_CA_CODE_PERIOD);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES);
// Loss of lock detection

2
src/algorithms/tracking/gnuradio_blocks/glonass_l1_ca_dll_pll_tracking_cc.cc
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@ -622,7 +622,7 @@ int Glonass_L1_Ca_Dll_Pll_Tracking_cc::general_work(int noutput_items __attribut
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, d_fs_in, GLONASS_L1_CA_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, GLONASS_L1_CA_CODE_PERIOD);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES);
// Loss of lock detection

2
src/algorithms/tracking/gnuradio_blocks/glonass_l2_ca_dll_pll_c_aid_tracking_cc.cc
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@ -759,7 +759,7 @@ int glonass_l2_ca_dll_pll_c_aid_tracking_cc::general_work(int noutput_items __at
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, d_fs_in, GLONASS_L2_CA_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, GLONASS_L2_CA_CODE_PERIOD);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES);
// Loss of lock detection

2
src/algorithms/tracking/gnuradio_blocks/glonass_l2_ca_dll_pll_c_aid_tracking_sc.cc
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@ -751,7 +751,7 @@ int glonass_l2_ca_dll_pll_c_aid_tracking_sc::general_work(int noutput_items __at
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, d_fs_in, GLONASS_L2_CA_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, GLONASS_L2_CA_CODE_PERIOD);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES);
// Loss of lock detection

2
src/algorithms/tracking/gnuradio_blocks/glonass_l2_ca_dll_pll_tracking_cc.cc
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@ -622,7 +622,7 @@ int Glonass_L2_Ca_Dll_Pll_Tracking_cc::general_work(int noutput_items __attribut
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, d_fs_in, GLONASS_L2_CA_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES, GLONASS_L2_CA_CODE_PERIOD);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, CN0_ESTIMATION_SAMPLES);
// Loss of lock detection

5
src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_c_aid_tracking_cc.cc
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@ -741,7 +741,7 @@ int gps_l1_ca_dll_pll_c_aid_tracking_cc::general_work(int noutput_items __attrib
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, d_fs_in, GPS_L1_CA_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, GPS_L1_CA_CODE_PERIOD);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, FLAGS_cn0_samples);
// Loss of lock detection
@ -842,7 +842,8 @@ int gps_l1_ca_dll_pll_c_aid_tracking_cc::general_work(int noutput_items __attrib
// PLL commands
tmp_float = 1.0 / (d_carr_phase_error_secs_Ti * CURRENT_INTEGRATION_TIME_S);
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
tmp_float = 1.0 / (d_code_error_filt_chips_Ti * CURRENT_INTEGRATION_TIME_S);;
tmp_float = 1.0 / (d_code_error_filt_chips_Ti * CURRENT_INTEGRATION_TIME_S);
;
d_dump_file.write(reinterpret_cast<char *>(&tmp_float), sizeof(float));
// DLL commands
tmp_float = d_code_error_chips_Ti * CURRENT_INTEGRATION_TIME_S;

2
src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_c_aid_tracking_fpga_sc.cc
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@ -558,7 +558,7 @@ int gps_l1_ca_dll_pll_c_aid_tracking_fpga_sc::general_work(
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, d_fs_in, GPS_L1_CA_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, GPS_L1_CA_CODE_PERIOD);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, FLAGS_cn0_samples);
// Loss of lock detection

2
src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_c_aid_tracking_sc.cc
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@ -743,7 +743,7 @@ int gps_l1_ca_dll_pll_c_aid_tracking_sc::general_work(int noutput_items __attrib
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, d_fs_in, GPS_L1_CA_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, GPS_L1_CA_CODE_PERIOD);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, FLAGS_cn0_samples);
// Loss of lock detection

2
src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_dll_pll_tracking_gpu_cc.cc
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@ -413,7 +413,7 @@ int Gps_L1_Ca_Dll_Pll_Tracking_GPU_cc::general_work(int noutput_items __attribut
{
d_cn0_estimation_counter = 0;
// Code lock indicator
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, d_fs_in, GPS_L1_CA_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, GPS_L1_CA_CODE_PERIOD);
// Carrier lock indicator
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, FLAGS_cn0_samples);
// Loss of lock detection

2
src/algorithms/tracking/gnuradio_blocks/gps_l1_ca_tcp_connector_tracking_cc.cc
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@ -418,7 +418,7 @@ int Gps_L1_Ca_Tcp_Connector_Tracking_cc::general_work(int noutput_items __attrib
else
{
d_cn0_estimation_counter = 0;
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, d_fs_in, GPS_L1_CA_CODE_LENGTH_CHIPS);
d_CN0_SNV_dB_Hz = cn0_svn_estimator(d_Prompt_buffer, FLAGS_cn0_samples, GPS_L1_CA_CODE_PERIOD);
d_carrier_lock_test = carrier_lock_detector(d_Prompt_buffer, FLAGS_cn0_samples);
// ###### TRACKING UNLOCK NOTIFICATION #####

10
src/algorithms/tracking/libs/lock_detectors.cc
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@ -58,14 +58,14 @@
* \f$\hat{P}_{tot}=\frac{1}{N}\sum^{N-1}_{i=0}|Pc(i)|^2\f$ is the estimator of the total power, \f$|\cdot|\f$ is the absolute value,
* \f$Re(\cdot)\f$ stands for the real part of the value, and \f$Pc(i)\f$ is the prompt correlator output for the sample index i.
*
* The SNR value is converted to CN0 [dB-Hz], taking to account the receiver bandwidth and the PRN code gain, using the following formula:
* The SNR value is converted to CN0 [dB-Hz], taking to account the coherent integration time, using the following formula:
* \f{equation}
* CN0_{dB}=10*log(\hat{\rho})+10*log(\frac{f_s}{2})-10*log(L_{PRN}),
* CN0_{dB}=10*log(\hat{\rho})-10*log(2 * T_{int}),
* \f}
* where \f$f_s\f$ is the sampling frequency and \f$L_{PRN}\f$ is the PRN sequence length.
* where \f$T_{int}\f$ is the coherent integration time, in seconds.
*
*/
float cn0_svn_estimator(gr_complex* Prompt_buffer, int length, long fs_in, double code_length)
float cn0_svn_estimator(const gr_complex* Prompt_buffer, int length, double coh_integration_time_s)
{
double SNR = 0.0;
double SNR_dB_Hz = 0.0;
@ -80,7 +80,7 @@ float cn0_svn_estimator(gr_complex* Prompt_buffer, int length, long fs_in, doubl
Psig = Psig * Psig;
Ptot /= static_cast<double>(length);
SNR = Psig / (Ptot - Psig);
SNR_dB_Hz = 10.0 * log10(SNR) + 10.0 * log10(static_cast<double>(fs_in) / 2.0) - 10.0 * log10(code_length);
SNR_dB_Hz = 10.0 * log10(SNR) - 10.0 * log10(2.0 * coh_integration_time_s);
return static_cast<float>(SNR_dB_Hz);
}

8
src/algorithms/tracking/libs/lock_detectors.h
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@ -62,17 +62,17 @@
* \f$\hat{P}_{tot}=\frac{1}{N}\sum^{N-1}_{i=0}|Pc(i)|^2\f$ is the estimator of the total power, \f$|\cdot|\f$ is the absolute value,
* \f$Re(\cdot)\f$ stands for the real part of the value, and \f$Pc(i)\f$ is the prompt correlator output for the sample index i.
*
* The SNR value is converted to CN0 [dB-Hz], taking to account the receiver bandwidth and the PRN code gain, using the following formula:
* The SNR value is converted to CN0 [dB-Hz], taking to account the coherent integration time, using the following formula:
* \f{equation}
* CN0_{dB}=10*log(\hat{\rho})+10*log(\frac{f_s}{2})-10*log(L_{PRN}),
* CN0_{dB}=10*log(\hat{\rho})-10*log(2 * T_{int}),
* \f}
* where \f$f_s\f$ is the sampling frequency and \f$L_{PRN}\f$ is the PRN sequence length.
* where \f$T_{int}\f$ is the coherent integration time, in seconds.
* Ref: Marco Pini, Emanuela Falletti and Maurizio Fantino, "Performance
* Evaluation of C/N0 Estimators using a Real Time GNSS Software Receiver,"
* IEEE 10th International Symposium on Spread Spectrum Techniques and
* Applications, pp.28-30, August 2008.
*/
float cn0_svn_estimator(gr_complex* Prompt_buffer, int length, long fs_in, double code_length);
float cn0_svn_estimator(const gr_complex* Prompt_buffer, int length, double coh_integration_time_s);
/*! \brief A carrier lock detector