mirrors/gnss-sdr
1
0
Fork 0
mirror of https://github.com/gnss-sdr/gnss-sdr synced 2024-12-15 12:40:35 +00:00
Code Issues Releases Wiki Activity

Add two step acquisition funcionality

Browse Source
This commit is contained in:
Antonio Ramos 2018-04-04 14:59:28 +02:00
parent bc6a568414
commit 44635a41b3
3 changed files with 224 additions and 99 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

314
src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.cc
View File

@ -88,11 +88,13 @@ pcps_acquisition::pcps_acquisition(
d_mag = 0;
d_input_power = 0.0;
d_num_doppler_bins = 0;
d_num_doppler_bins_step_two = 4;
d_bit_transition_flag = bit_transition_flag;
d_use_CFAR_algorithm_flag = use_CFAR_algorithm_flag;
d_threshold = 0.0;
d_doppler_step = 0;
d_code_phase = 0;
d_doppler_step_two = 0.0;
d_doppler_center_step_two = 0.0;
d_test_statistics = 0.0;
d_channel = 0;
if (it_size == sizeof(gr_complex))
@ -133,7 +135,8 @@ pcps_acquisition::pcps_acquisition(
d_dump = dump;
d_dump_filename = dump_filename;
d_gnss_synchro = 0;
d_grid_doppler_wipeoffs = 0;
d_grid_doppler_wipeoffs = nullptr;
d_grid_doppler_wipeoffs_step_two = nullptr;
d_blocking = blocking;
d_worker_active = false;
d_data_buffer = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_fft_size * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
@ -146,6 +149,7 @@ pcps_acquisition::pcps_acquisition(
d_data_buffer_sc = nullptr;
}
grid_ = arma::fmat();
d_step_two = false;
}
@ -159,6 +163,14 @@ pcps_acquisition::~pcps_acquisition()
}
delete[] d_grid_doppler_wipeoffs;
}
if (d_num_doppler_bins_step_two > 0)
{
for (unsigned int i = 0; i < d_num_doppler_bins_step_two; i++)
{
volk_gnsssdr_free(d_grid_doppler_wipeoffs_step_two[i]);
}
delete[] d_grid_doppler_wipeoffs_step_two;
}
volk_gnsssdr_free(d_fft_codes);
volk_gnsssdr_free(d_magnitude);
delete d_ifft;
@ -249,13 +261,18 @@ void pcps_acquisition::init()
// Create the carrier Doppler wipeoff signals
d_grid_doppler_wipeoffs = new gr_complex*[d_num_doppler_bins];
d_grid_doppler_wipeoffs_step_two = new gr_complex*[d_num_doppler_bins_step_two];
for (unsigned int doppler_index = 0; doppler_index < d_num_doppler_bins; doppler_index++)
{
d_grid_doppler_wipeoffs[doppler_index] = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_fft_size * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
int doppler = -static_cast<int>(d_doppler_max) + d_doppler_step * doppler_index;
update_local_carrier(d_grid_doppler_wipeoffs[doppler_index], d_fft_size, d_freq + doppler);
}
for (unsigned int doppler_index = 0; doppler_index < d_num_doppler_bins_step_two; doppler_index++)
{
d_grid_doppler_wipeoffs_step_two[doppler_index] = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_fft_size * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
}
d_worker_active = false;
if (d_dump)
@ -270,12 +287,21 @@ void pcps_acquisition::update_grid_doppler_wipeoffs()
{
for (unsigned int doppler_index = 0; doppler_index < d_num_doppler_bins; doppler_index++)
{
d_grid_doppler_wipeoffs[doppler_index] = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_fft_size * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
//CHECK IF CALLING MALLOC IS NEEDED!!!
//d_grid_doppler_wipeoffs[doppler_index] = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_fft_size * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
int doppler = -static_cast<int>(d_doppler_max) + d_doppler_step * doppler_index;
update_local_carrier(d_grid_doppler_wipeoffs[doppler_index], d_fft_size, d_freq + doppler);
}
}
void pcps_acquisition::update_grid_doppler_wipeoffs_step2()
{
for (unsigned int doppler_index = 0; doppler_index < d_num_doppler_bins_step_two; doppler_index++)
{
float doppler = (static_cast<float>(doppler_index) - static_cast<float>(d_num_doppler_bins_step_two) / 2.0) * d_doppler_step_two;
update_local_carrier(d_grid_doppler_wipeoffs_step_two[doppler_index], d_fft_size, d_doppler_center_step_two + doppler);
}
}
void pcps_acquisition::set_state(int state)
{
@ -354,10 +380,17 @@ int pcps_acquisition::general_work(int noutput_items __attribute__((unused)),
*/
gr::thread::scoped_lock lk(d_setlock);
if (!d_active || d_worker_active)
if (!d_active or d_worker_active)
{
d_sample_counter += d_fft_size * ninput_items[0];
consume_each(ninput_items[0]);
if (d_step_two)
{
d_doppler_center_step_two = static_cast<float>(d_gnss_synchro->Acq_doppler_hz);
update_grid_doppler_wipeoffs_step2();
d_state = 0;
d_active = true;
}
return 0;
}
@ -414,7 +447,6 @@ void pcps_acquisition::acquisition_core(unsigned long int samp_count)
gr::thread::scoped_lock lk(d_setlock);
// initialize acquisition algorithm
int doppler;
uint32_t indext = 0;
float magt = 0.0;
const gr_complex* in = d_data_buffer; //Get the input samples pointer
@ -445,105 +477,172 @@ void pcps_acquisition::acquisition_core(unsigned long int samp_count)
d_input_power /= static_cast<float>(d_fft_size);
}
// 2- Doppler frequency search loop
for (unsigned int doppler_index = 0; doppler_index < d_num_doppler_bins; doppler_index++)
if (!d_step_two)
{
// doppler search steps
doppler = -static_cast<int>(d_doppler_max) + d_doppler_step * doppler_index;
volk_32fc_x2_multiply_32fc(d_fft_if->get_inbuf(), in, d_grid_doppler_wipeoffs[doppler_index], d_fft_size);
// 3- Perform the FFT-based convolution (parallel time search)
// Compute the FFT of the carrier wiped--off incoming signal
d_fft_if->execute();
// Multiply carrier wiped--off, Fourier transformed incoming signal
// with the local FFT'd code reference using SIMD operations with VOLK library
volk_32fc_x2_multiply_32fc(d_ifft->get_inbuf(), d_fft_if->get_outbuf(), d_fft_codes, d_fft_size);
// compute the inverse FFT
d_ifft->execute();
// Search maximum
size_t offset = (d_bit_transition_flag ? effective_fft_size : 0);
volk_32fc_magnitude_squared_32f(d_magnitude, d_ifft->get_outbuf() + offset, effective_fft_size);
volk_gnsssdr_32f_index_max_32u(&indext, d_magnitude, effective_fft_size);
magt = d_magnitude[indext];
if (d_use_CFAR_algorithm_flag)
for (unsigned int doppler_index = 0; doppler_index < d_num_doppler_bins; doppler_index++)
{
// Normalize the maximum value to correct the scale factor introduced by FFTW
magt = d_magnitude[indext] / (fft_normalization_factor * fft_normalization_factor);
}
// 4- record the maximum peak and the associated synchronization parameters
if (d_mag < magt)
{
d_mag = magt;
// doppler search steps
int doppler = -static_cast<int>(d_doppler_max) + d_doppler_step * doppler_index;
if (!d_use_CFAR_algorithm_flag)
volk_32fc_x2_multiply_32fc(d_fft_if->get_inbuf(), in, d_grid_doppler_wipeoffs[doppler_index], d_fft_size);
// 3- Perform the FFT-based convolution (parallel time search)
// Compute the FFT of the carrier wiped--off incoming signal
d_fft_if->execute();
// Multiply carrier wiped--off, Fourier transformed incoming signal
// with the local FFT'd code reference using SIMD operations with VOLK library
volk_32fc_x2_multiply_32fc(d_ifft->get_inbuf(), d_fft_if->get_outbuf(), d_fft_codes, d_fft_size);
// compute the inverse FFT
d_ifft->execute();
// Search maximum
size_t offset = (d_bit_transition_flag ? effective_fft_size : 0);
volk_32fc_magnitude_squared_32f(d_magnitude, d_ifft->get_outbuf() + offset, effective_fft_size);
volk_gnsssdr_32f_index_max_32u(&indext, d_magnitude, effective_fft_size);
magt = d_magnitude[indext];
if (d_use_CFAR_algorithm_flag)
{
// Search grid noise floor approximation for this doppler line
volk_32f_accumulator_s32f(&d_input_power, d_magnitude, effective_fft_size);
d_input_power = (d_input_power - d_mag) / (effective_fft_size - 1);
// Normalize the maximum value to correct the scale factor introduced by FFTW
magt = d_magnitude[indext] / (fft_normalization_factor * fft_normalization_factor);
}
// In case that d_bit_transition_flag = true, we compare the potentially
// new maximum test statistics (d_mag/d_input_power) with the value in
// d_test_statistics. When the second dwell is being processed, the value
// of d_mag/d_input_power could be lower than d_test_statistics (i.e,
// the maximum test statistics in the previous dwell is greater than
// current d_mag/d_input_power). Note that d_test_statistics is not
// restarted between consecutive dwells in multidwell operation.
if (d_test_statistics < (d_mag / d_input_power) || !d_bit_transition_flag)
// 4- record the maximum peak and the associated synchronization parameters
if (d_mag < magt)
{
d_gnss_synchro->Acq_delay_samples = static_cast<double>(indext % d_samples_per_code);
d_gnss_synchro->Acq_doppler_hz = static_cast<double>(doppler);
d_gnss_synchro->Acq_samplestamp_samples = samp_count;
d_mag = magt;
// 5- Compute the test statistics and compare to the threshold
//d_test_statistics = 2 * d_fft_size * d_mag / d_input_power;
d_test_statistics = d_mag / d_input_power;
}
}
// Record results to file if required
if (d_dump)
{
memcpy(grid_.colptr(doppler_index), d_magnitude, sizeof(float) * effective_fft_size);
if (doppler_index == (d_num_doppler_bins - 1))
{
std::string filename = d_dump_filename;
filename.append("_");
filename.append(1, d_gnss_synchro->System);
filename.append("_");
filename.append(1, d_gnss_synchro->Signal[0]);
filename.append(1, d_gnss_synchro->Signal[1]);
filename.append("_sat_");
filename.append(std::to_string(d_gnss_synchro->PRN));
filename.append(".mat");
mat_t* matfp = Mat_CreateVer(filename.c_str(), NULL, MAT_FT_MAT73);
if (matfp == NULL)
if (!d_use_CFAR_algorithm_flag)
{
std::cout << "Unable to create or open Acquisition dump file" << std::endl;
d_dump = false;
// Search grid noise floor approximation for this doppler line
volk_32f_accumulator_s32f(&d_input_power, d_magnitude, effective_fft_size);
d_input_power = (d_input_power - d_mag) / (effective_fft_size - 1);
}
else
// In case that d_bit_transition_flag = true, we compare the potentially
// new maximum test statistics (d_mag/d_input_power) with the value in
// d_test_statistics. When the second dwell is being processed, the value
// of d_mag/d_input_power could be lower than d_test_statistics (i.e,
// the maximum test statistics in the previous dwell is greater than
// current d_mag/d_input_power). Note that d_test_statistics is not
// restarted between consecutive dwells in multidwell operation.
if (d_test_statistics < (d_mag / d_input_power) or !d_bit_transition_flag)
{
size_t dims[2] = {static_cast<size_t>(effective_fft_size), static_cast<size_t>(d_num_doppler_bins)};
matvar_t* matvar = Mat_VarCreate("grid", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, grid_.memptr(), 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
d_gnss_synchro->Acq_delay_samples = static_cast<double>(indext % d_samples_per_code);
d_gnss_synchro->Acq_doppler_hz = static_cast<double>(doppler);
d_gnss_synchro->Acq_samplestamp_samples = samp_count;
dims[0] = static_cast<size_t>(1);
dims[1] = static_cast<size_t>(1);
matvar = Mat_VarCreate("doppler_max", MAT_C_SINGLE, MAT_T_UINT32, 1, dims, &d_doppler_max, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
// 5- Compute the test statistics and compare to the threshold
//d_test_statistics = 2 * d_fft_size * d_mag / d_input_power;
d_test_statistics = d_mag / d_input_power;
}
}
// Record results to file if required
if (d_dump)
{
memcpy(grid_.colptr(doppler_index), d_magnitude, sizeof(float) * effective_fft_size);
if (doppler_index == (d_num_doppler_bins - 1))
{
std::string filename = d_dump_filename;
filename.append("_");
filename.append(1, d_gnss_synchro->System);
filename.append("_");
filename.append(1, d_gnss_synchro->Signal[0]);
filename.append(1, d_gnss_synchro->Signal[1]);
filename.append("_sat_");
filename.append(std::to_string(d_gnss_synchro->PRN));
filename.append(".mat");
mat_t* matfp = Mat_CreateVer(filename.c_str(), NULL, MAT_FT_MAT73);
if (matfp == NULL)
{
std::cout << "Unable to create or open Acquisition dump file" << std::endl;
d_dump = false;
}
else
{
size_t dims[2] = {static_cast<size_t>(effective_fft_size), static_cast<size_t>(d_num_doppler_bins)};
matvar_t* matvar = Mat_VarCreate("grid", MAT_C_SINGLE, MAT_T_SINGLE, 2, dims, grid_.memptr(), 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
matvar = Mat_VarCreate("doppler_step", MAT_C_SINGLE, MAT_T_UINT32, 1, dims, &d_doppler_step, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
dims[0] = static_cast<size_t>(1);
dims[1] = static_cast<size_t>(1);
matvar = Mat_VarCreate("doppler_max", MAT_C_SINGLE, MAT_T_UINT32, 1, dims, &d_doppler_max, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
Mat_Close(matfp);
matvar = Mat_VarCreate("doppler_step", MAT_C_SINGLE, MAT_T_UINT32, 1, dims, &d_doppler_step, 0);
Mat_VarWrite(matfp, matvar, MAT_COMPRESSION_ZLIB); // or MAT_COMPRESSION_NONE
Mat_VarFree(matvar);
Mat_Close(matfp);
}
}
}
}
}
else
{
for (unsigned int doppler_index = 0; doppler_index < d_num_doppler_bins_step_two; doppler_index++)
{
// doppler search steps
float doppler = d_doppler_center_step_two + (static_cast<float>(doppler_index) - static_cast<float>(d_num_doppler_bins_step_two) / 2.0) * d_doppler_step_two;
volk_32fc_x2_multiply_32fc(d_fft_if->get_inbuf(), in, d_grid_doppler_wipeoffs_step_two[doppler_index], d_fft_size);
// 3- Perform the FFT-based convolution (parallel time search)
// Compute the FFT of the carrier wiped--off incoming signal
d_fft_if->execute();
// Multiply carrier wiped--off, Fourier transformed incoming signal
// with the local FFT'd code reference using SIMD operations with VOLK library
volk_32fc_x2_multiply_32fc(d_ifft->get_inbuf(), d_fft_if->get_outbuf(), d_fft_codes, d_fft_size);
// compute the inverse FFT
d_ifft->execute();
// Search maximum
size_t offset = (d_bit_transition_flag ? effective_fft_size : 0);
volk_32fc_magnitude_squared_32f(d_magnitude, d_ifft->get_outbuf() + offset, effective_fft_size);
volk_gnsssdr_32f_index_max_32u(&indext, d_magnitude, effective_fft_size);
magt = d_magnitude[indext];
if (d_use_CFAR_algorithm_flag)
{
// Normalize the maximum value to correct the scale factor introduced by FFTW
magt = d_magnitude[indext] / (fft_normalization_factor * fft_normalization_factor);
}
// 4- record the maximum peak and the associated synchronization parameters
if (d_mag < magt)
{
d_mag = magt;
if (!d_use_CFAR_algorithm_flag)
{
// Search grid noise floor approximation for this doppler line
volk_32f_accumulator_s32f(&d_input_power, d_magnitude, effective_fft_size);
d_input_power = (d_input_power - d_mag) / (effective_fft_size - 1);
}
// In case that d_bit_transition_flag = true, we compare the potentially
// new maximum test statistics (d_mag/d_input_power) with the value in
// d_test_statistics. When the second dwell is being processed, the value
// of d_mag/d_input_power could be lower than d_test_statistics (i.e,
// the maximum test statistics in the previous dwell is greater than
// current d_mag/d_input_power). Note that d_test_statistics is not
// restarted between consecutive dwells in multidwell operation.
if (d_test_statistics < (d_mag / d_input_power) or !d_bit_transition_flag)
{
d_gnss_synchro->Acq_delay_samples = static_cast<double>(indext % d_samples_per_code);
d_gnss_synchro->Acq_doppler_hz = static_cast<double>(doppler);
d_gnss_synchro->Acq_samplestamp_samples = samp_count;
// 5- Compute the test statistics and compare to the threshold
//d_test_statistics = 2 * d_fft_size * d_mag / d_input_power;
d_test_statistics = d_mag / d_input_power;
}
}
}
@ -553,14 +652,24 @@ void pcps_acquisition::acquisition_core(unsigned long int samp_count)
{
if (d_test_statistics > d_threshold)
{
d_state = 0; // Positive acquisition
d_active = false;
send_positive_acquisition();
if (d_step_two)
{
send_positive_acquisition();
d_step_two = false;
d_state = 0; // Positive acquisition
}
else
{
d_step_two = true; // Clear input buffer and make small grid acquisition
d_state = 0;
}
}
else if (d_well_count == d_max_dwells)
{
d_state = 0;
d_active = false;
d_step_two = false;
send_negative_acquisition();
}
}
@ -568,16 +677,25 @@ void pcps_acquisition::acquisition_core(unsigned long int samp_count)
{
if (d_well_count == d_max_dwells) // d_max_dwells = 2
{
d_active = false;
if (d_test_statistics > d_threshold)
{
d_state = 0; // Positive acquisition
d_active = false;
send_positive_acquisition();
if (d_step_two)
{
send_positive_acquisition();
d_step_two = false;
d_state = 0; // Positive acquisition
}
else
{
d_step_two = true; // Clear input buffer and make small grid acquisition
d_state = 0;
}
}
else
{
d_state = 0; // Negative acquisition
d_active = false;
d_step_two = false;
send_negative_acquisition();
}
}

8
src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.h
View File

@ -98,6 +98,7 @@ private:
void update_local_carrier(gr_complex* carrier_vector, int correlator_length_samples, float freq);
void update_grid_doppler_wipeoffs();
void update_grid_doppler_wipeoffs_step2();
bool is_fdma();
void acquisition_core(unsigned long int samp_count);
@ -113,6 +114,7 @@ private:
bool d_worker_active;
bool d_blocking;
bool d_cshort;
bool d_step_two;
float d_threshold;
float d_mag;
float d_input_power;
@ -127,14 +129,17 @@ private:
unsigned int d_channel;
unsigned int d_doppler_max;
unsigned int d_doppler_step;
float d_doppler_step_two;
float d_doppler_center_step_two;
unsigned int d_sampled_ms;
unsigned int d_max_dwells;
unsigned int d_well_count;
unsigned int d_fft_size;
unsigned int d_num_doppler_bins;
unsigned int d_code_phase;
unsigned int d_num_doppler_bins_step_two;
unsigned long int d_sample_counter;
gr_complex** d_grid_doppler_wipeoffs;
gr_complex** d_grid_doppler_wipeoffs_step_two;
gr_complex* d_fft_codes;
gr_complex* d_data_buffer;
lv_16sc_t* d_data_buffer_sc;
@ -234,6 +239,7 @@ public:
{
gr::thread::scoped_lock lock(d_setlock); // require mutex with work function called by the scheduler
d_doppler_step = doppler_step;
d_doppler_step_two = static_cast<float>(d_doppler_step) / 2.0;
}
/*!

1
src/algorithms/tracking/gnuradio_blocks/dll_pll_veml_tracking.cc
View File

@ -430,6 +430,7 @@ void dll_pll_veml_tracking::start_tracking()
long int acq_trk_diff_samples = static_cast<long int>(d_sample_counter) - static_cast<long int>(d_acq_sample_stamp);
double acq_trk_diff_seconds = static_cast<double>(acq_trk_diff_samples) / d_fs_in;
std::cout << "ACQ to TRK diff seconds = " << acq_trk_diff_seconds << std::endl;
DLOG(INFO) << "Number of samples between Acquisition and Tracking = " << acq_trk_diff_samples;
DLOG(INFO) << "Number of seconds between Acquisition and Tracking = " << acq_trk_diff_seconds;
// Doppler effect Fd = (C / (C + Vr)) * F