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use of the :2 decimator in the GPS L1/Galileo E1 frequency band

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added methods to the L1 and E1 FPGA acquisition classes for the unit tests to be able to control the doppler sweep from the SW instead of the HW. In this way we can produce more detailed results.
This commit is contained in:
Marc Majoral
2018-10-04 17:49:09 +02:00
parent df3caf5c2b
commit 2826dd21d3
9 changed files with 95 additions and 18 deletions
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3
src/algorithms/acquisition/adapters/galileo_e1_pcps_ambiguous_acquisition_fpga.cc
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@@ -59,8 +59,9 @@ GalileoE1PcpsAmbiguousAcquisitionFpga::GalileoE1PcpsAmbiguousAcquisitionFpga(
long fs_in_deprecated = configuration_->property("GNSS-SDR.internal_fs_hz", 4000000);
long fs_in = configuration_->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
float downsampling_factor = configuration_->property("GNSS-SDR.downsampling_factor", 1.0);
float downsampling_factor = configuration_->property("GNSS-SDR.downsampling_factor", 2.0);
acq_parameters.downsampling_factor = downsampling_factor;
//fs_in = fs_in/2.0; // downampling filter
//printf("fs_in pre downsampling = %ld\n", fs_in);

2
src/algorithms/acquisition/adapters/gps_l1_ca_pcps_acquisition_fpga.cc
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@@ -61,7 +61,7 @@ GpsL1CaPcpsAcquisitionFpga::GpsL1CaPcpsAcquisitionFpga(
long fs_in_deprecated = configuration_->property("GNSS-SDR.internal_fs_hz", 2048000);
long fs_in = configuration_->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
float downsampling_factor = configuration_->property("GNSS-SDR.downsampling_factor", 1.0);
float downsampling_factor = configuration_->property("GNSS-SDR.downsampling_factor", 2.0);
acq_parameters.downsampling_factor = downsampling_factor;
//fs_in = fs_in/2.0; // downampling filter
//printf("fs_in pre downsampling = %ld\n", fs_in);

30
src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_fpga.cc
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@@ -75,8 +75,10 @@ pcps_acquisition_fpga::pcps_acquisition_fpga(pcpsconf_fpga_t conf_) : gr::block(
d_test_statistics = 0.0;
d_channel = 0U;
d_gnss_synchro = 0;
d_single_doppler_flag = false;
d_downsampling_factor = acq_parameters.downsampling_factor;
printf("downsampling_factor = %f\n", d_downsampling_factor);
d_select_queue_Fpga = acq_parameters.select_queue_Fpga;
//printf("zzzz acq_parameters.code_length = %d\n", acq_parameters.code_length);
//printf("zzzz acq_parameters.samples_per_ms = %d\n", acq_parameters.samples_per_ms);
@@ -300,10 +302,21 @@ void pcps_acquisition_fpga::set_active(bool active)
// temp_d_input_power = d_input_power;
d_input_power = (d_input_power - d_mag) / (d_fft_size - 1);
int32_t doppler = -static_cast<int32_t>(acq_parameters.doppler_max) + d_doppler_step * (d_doppler_index - 1);
int32_t doppler;
if (d_single_doppler_flag == false)
{
doppler = -static_cast<int32_t>(acq_parameters.doppler_max) + d_doppler_step * (d_doppler_index - 1);
//doppler = -static_cast<int32_t>(acq_parameters.doppler_max) + d_doppler_step * (d_doppler_index); // this is the wrong one
}
else
{
doppler = static_cast<int32_t>(acq_parameters.doppler_max);
}
//d_gnss_synchro->Acq_delay_samples = static_cast<double>(2*(indext % (2*acq_parameters.samples_per_code)));
//printf("acq gnuradioblock doppler = %d\n", doppler);
d_gnss_synchro->Acq_doppler_hz = static_cast<double>(doppler);
d_sample_counter = initial_sample;
@@ -311,13 +324,21 @@ void pcps_acquisition_fpga::set_active(bool active)
{
if (d_downsampling_factor > 1)
{
//printf("yes here\n");
d_gnss_synchro->Acq_delay_samples = static_cast<double>(d_downsampling_factor*(indext % acq_parameters.samples_per_code));
d_gnss_synchro->Acq_samplestamp_samples = d_downsampling_factor*d_sample_counter - 81*0.5*d_downsampling_factor; // delay due to the downsampling filter in the acquisition
d_gnss_synchro->Acq_samplestamp_samples = d_downsampling_factor*d_sample_counter - 81*0.25*d_downsampling_factor; // delay due to the downsampling filter in the acquisition
//d_gnss_synchro->Acq_delay_samples = static_cast<double>(2*(indext % acq_parameters.samples_per_code));
//d_gnss_synchro->Acq_delay_samples = static_cast<double>(2*(indext));
//d_gnss_synchro->Acq_samplestamp_samples = d_sample_counter*2 - 81;
//d_gnss_synchro->Acq_delay_samples = static_cast<double>(indext % acq_parameters.samples_per_code);
//d_gnss_synchro->Acq_samplestamp_samples = d_sample_counter;
}
else
{
d_gnss_synchro->Acq_delay_samples = static_cast<double>(indext % acq_parameters.samples_per_code);
d_gnss_synchro->Acq_samplestamp_samples = d_sample_counter; // delay due to the downsampling filter in the acquisition
//d_gnss_synchro->Acq_samplestamp_samples = d_sample_counter - 40; // delay due to the downsampling filter in the acquisition
//d_gnss_synchro->Acq_samplestamp_samples = d_downsampling_factor*d_sample_counter - 81*0.5*d_downsampling_factor;
}
}
else
@@ -364,6 +385,10 @@ void pcps_acquisition_fpga::set_active(bool active)
// printf("##### debug_doppler_index = %d\n",debug_doppler_index);
send_positive_acquisition();
d_state = 0; // Positive acquisition
//printf("acq d_gnss_synchro->Acq_delay_samples = %f\n: ",d_gnss_synchro->Acq_delay_samples);
//printf("acq d_gnss_synchro->Acq_samplestamp_samples = %d\n", (unsigned int) d_gnss_synchro->Acq_samplestamp_samples);
}
else
{
@@ -390,6 +415,7 @@ int pcps_acquisition_fpga::general_work(int noutput_items __attribute__((unused)
void pcps_acquisition_fpga::set_single_doppler_flag(unsigned int single_doppler_flag)
{
acquisition_fpga->set_single_doppler_flag(single_doppler_flag);
d_single_doppler_flag = true;
}
// this function is only used for the unit tests

2
src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_fpga.h
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@@ -126,7 +126,7 @@ private:
float d_downsampling_factor;
uint32_t d_select_queue_Fpga;
bool d_single_doppler_flag;
public:

2
src/algorithms/acquisition/libs/fpga_acquisition.cc
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@@ -327,7 +327,7 @@ void fpga_acquisition::set_doppler_sweep(uint32_t num_sweeps)
d_map_base[3] = phase_step_rad_int;
// repeat the calculation with the doppler step
doppler = 0;
doppler = static_cast<int32_t>(d_doppler_step);
phase_step_rad = GPS_TWO_PI * (doppler) / static_cast<float>(d_fs_in);
phase_step_rad_real = phase_step_rad / (GPS_TWO_PI / 2);
//printf("AAA phase_step_rad_real for doppler step = %f\n", phase_step_rad_real);

2
src/algorithms/acquisition/libs/fpga_acquisition.h
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@@ -76,6 +76,7 @@ public:
{
//printf("acq lib set doppler max called\n");
d_doppler_max = doppler_max;
//printf("set acq lib d_doppler_max = %d\n", (int) d_doppler_max);
}
/*!
@@ -86,6 +87,7 @@ public:
{
//printf("acq lib set doppler step called\n");
d_doppler_step = doppler_step;
//printf("set acq lib d_doppler_step = %d\n", (int) d_doppler_step);
}
/*!