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Code Issues Releases Wiki Activity

Fix coherent acquisition

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This commit is contained in:
Carles Fernandez 2018-07-10 16:25:16 +02:00
parent 394f6088aa
commit 85f70fe1a3
3 changed files with 44 additions and 16 deletions
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56
src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.cc
View File

@ -64,7 +64,16 @@ pcps_acquisition::pcps_acquisition(const Acq_Conf& conf_) : gr::block("pcps_acqu
d_state = 0;
d_old_freq = 0;
d_num_noncoherent_integrations_counter = 0;
d_fft_size = acq_parameters.sampled_ms * acq_parameters.samples_per_ms;
d_consumed_samples = acq_parameters.sampled_ms * acq_parameters.samples_per_ms * (acq_parameters.bit_transition_flag ? 2 : 1);
if (acq_parameters.sampled_ms == 1)
{
d_fft_size = d_consumed_samples;
}
else
{
d_fft_size = d_consumed_samples * 2;
}
//d_fft_size = next power of two? ////
d_mag = 0;
d_input_power = 0.0;
d_num_doppler_bins = 0;
@ -82,8 +91,6 @@ pcps_acquisition::pcps_acquisition(const Acq_Conf& conf_) : gr::block("pcps_acqu
d_cshort = true;
}
d_tmp_buffer = static_cast<float*>(volk_gnsssdr_malloc(d_fft_size * sizeof(float), volk_gnsssdr_get_alignment()));
// COD:
// Experimenting with the overlap/save technique for handling bit trannsitions
// The problem: Circular correlation is asynchronous with the received code.
@ -96,12 +103,14 @@ pcps_acquisition::pcps_acquisition(const Acq_Conf& conf_) : gr::block("pcps_acqu
// size of the input buffer and padding the code with zeros.
if (acq_parameters.bit_transition_flag)
{
d_fft_size *= 2;
d_fft_size = d_consumed_samples * 2;
acq_parameters.max_dwells = 1; // Activation of acq_parameters.bit_transition_flag invalidates the value of acq_parameters.max_dwells
}
d_tmp_buffer = static_cast<float*>(volk_gnsssdr_malloc(d_fft_size * sizeof(float), volk_gnsssdr_get_alignment()));
d_fft_codes = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_fft_size * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
d_magnitude = static_cast<float*>(volk_gnsssdr_malloc(d_fft_size * sizeof(float), volk_gnsssdr_get_alignment()));
d_input_signal = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_fft_size * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
// Direct FFT
d_fft_if = new gr::fft::fft_complex(d_fft_size, true);
@ -114,10 +123,10 @@ pcps_acquisition::pcps_acquisition(const Acq_Conf& conf_) : gr::block("pcps_acqu
d_grid_doppler_wipeoffs_step_two = nullptr;
d_magnitude_grid = nullptr;
d_worker_active = false;
d_data_buffer = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_fft_size * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
d_data_buffer = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_consumed_samples * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
if (d_cshort)
{
d_data_buffer_sc = static_cast<lv_16sc_t*>(volk_gnsssdr_malloc(d_fft_size * sizeof(lv_16sc_t), volk_gnsssdr_get_alignment()));
d_data_buffer_sc = static_cast<lv_16sc_t*>(volk_gnsssdr_malloc(d_consumed_samples * sizeof(lv_16sc_t), volk_gnsssdr_get_alignment()));
}
else
{
@ -163,6 +172,7 @@ pcps_acquisition::~pcps_acquisition()
volk_gnsssdr_free(d_fft_codes);
volk_gnsssdr_free(d_magnitude);
volk_gnsssdr_free(d_tmp_buffer);
volk_gnsssdr_free(d_input_signal);
delete d_ifft;
delete d_fft_if;
volk_gnsssdr_free(d_data_buffer);
@ -195,7 +205,15 @@ void pcps_acquisition::set_local_code(std::complex<float>* code)
}
else
{
memcpy(d_fft_if->get_inbuf(), code, sizeof(gr_complex) * d_fft_size);
if (acq_parameters.sampled_ms == 1)
{
memcpy(d_fft_if->get_inbuf(), code, sizeof(gr_complex) * d_consumed_samples);
}
else
{
std::fill_n(d_fft_if->get_inbuf(), d_fft_size - d_consumed_samples, gr_complex(0.0, 0.0));
memcpy(d_fft_if->get_inbuf() + d_consumed_samples, code, sizeof(gr_complex) * d_consumed_samples);
}
}
d_fft_if->execute(); // We need the FFT of local code
@ -530,12 +548,20 @@ void pcps_acquisition::acquisition_core(unsigned long int samp_count)
float magt = 0.0;
int doppler = 0;
uint32_t indext = 0;
const gr_complex* in = d_data_buffer; // Get the input samples pointer
int effective_fft_size = (acq_parameters.bit_transition_flag ? d_fft_size / 2 : d_fft_size);
if (d_cshort)
{
volk_gnsssdr_16ic_convert_32fc(d_data_buffer, d_data_buffer_sc, d_fft_size);
volk_gnsssdr_16ic_convert_32fc(d_data_buffer, d_data_buffer_sc, d_consumed_samples);
}
memcpy(d_input_signal, d_data_buffer, d_consumed_samples * sizeof(gr_complex));
if (d_fft_size > d_consumed_samples)
{
for (unsigned int i = d_consumed_samples; i < d_fft_size; i++)
{
d_input_signal[i] = gr_complex(0.0, 0.0);
}
}
const gr_complex* in = d_input_signal; // Get the input samples pointer
float fft_normalization_factor = static_cast<float>(d_fft_size) * static_cast<float>(d_fft_size);
d_input_power = 0.0;
@ -551,7 +577,7 @@ void pcps_acquisition::acquisition_core(unsigned long int samp_count)
lk.unlock();
if (d_use_CFAR_algorithm_flag)
if (d_use_CFAR_algorithm_flag or acq_parameters.bit_transition_flag)
{
// Compute the input signal power estimation
volk_32fc_magnitude_squared_32f(d_tmp_buffer, in, d_fft_size);
@ -780,7 +806,7 @@ int pcps_acquisition::general_work(int noutput_items __attribute__((unused)),
{
if (!acq_parameters.blocking_on_standby)
{
d_sample_counter += d_fft_size * ninput_items[0];
d_sample_counter += d_consumed_samples * ninput_items[0];
consume_each(ninput_items[0]);
}
if (d_step_two)
@ -807,7 +833,7 @@ int pcps_acquisition::general_work(int noutput_items __attribute__((unused)),
d_state = 1;
if (!acq_parameters.blocking_on_standby)
{
d_sample_counter += d_fft_size * ninput_items[0]; // sample counter
d_sample_counter += d_consumed_samples * ninput_items[0]; // sample counter
consume_each(ninput_items[0]);
}
break;
@ -818,11 +844,11 @@ int pcps_acquisition::general_work(int noutput_items __attribute__((unused)),
// Copy the data to the core and let it know that new data is available
if (d_cshort)
{
memcpy(d_data_buffer_sc, input_items[0], d_fft_size * sizeof(lv_16sc_t));
memcpy(d_data_buffer_sc, input_items[0], d_consumed_samples * sizeof(lv_16sc_t));
}
else
{
memcpy(d_data_buffer, input_items[0], d_fft_size * sizeof(gr_complex));
memcpy(d_data_buffer, input_items[0], d_consumed_samples * sizeof(gr_complex));
}
if (acq_parameters.blocking)
{
@ -834,7 +860,7 @@ int pcps_acquisition::general_work(int noutput_items __attribute__((unused)),
gr::thread::thread d_worker(&pcps_acquisition::acquisition_core, this, d_sample_counter);
d_worker_active = true;
}
d_sample_counter += d_fft_size;
d_sample_counter += d_consumed_samples;
consume_each(1);
break;
}

2
src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition.h
View File

@ -112,6 +112,7 @@ private:
float* d_magnitude;
float** d_magnitude_grid;
float* d_tmp_buffer;
gr_complex* d_input_signal;
uint32_t samplesPerChip;
long d_old_freq;
int d_state;
@ -120,6 +121,7 @@ private:
float d_doppler_center_step_two;
unsigned int d_num_noncoherent_integrations_counter;
unsigned int d_fft_size;
unsigned int d_consumed_samples;
unsigned int d_num_doppler_bins;
unsigned long int d_sample_counter;
gr_complex** d_grid_doppler_wipeoffs;

2
src/tests/unit-tests/signal-processing-blocks/acquisition/gps_l1_acq_performance_test.cc
View File

@ -707,7 +707,7 @@ TEST_F(AcquisitionPerformanceTest, ROC)
std::cout << "Num executions: " << num_executions << std::endl;
for (int execution = 1; execution <= num_executions; execution++)
{
acquisition_dump_reader acq_dump(basename, observed_satellite, config->property("Acquisition_1C.doppler_max", 0), config->property("Acquisition_1C.doppler_step", 0), config->property("GNSS-SDR.internal_fs_sps", 0) * GPS_L1_CA_CODE_PERIOD * static_cast<double>(coh_time_ms), ch, execution);
acquisition_dump_reader acq_dump(basename, observed_satellite, config->property("Acquisition_1C.doppler_max", 0), config->property("Acquisition_1C.doppler_step", 0), config->property("GNSS-SDR.internal_fs_sps", 0) * GPS_L1_CA_CODE_PERIOD * static_cast<double>(coh_time_ms) * (config->property("Acquisition_1C.bit_transition_flag", false) ? 2 : 1), ch, execution);
acq_dump.read_binary_acq();
if (acq_dump.positive_acq)
{