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Added 'blocking' option to pcps_acquisition_cc 

Using C++ 11 threading routines to create a worker thread that can
perform the FFT for acquisition in a non-blocking manner. By default
'blocking' is set to true, which is identical to the previous behaviour
(with the added overhead of an extra thread). When 'blocking' is set to
false, then the main thread does not wait for the worker, thereby
letting the receiver continue even when the FFT thread is working. This
is very useful for using FFT acquisition at higher sampling rates, where
the FFT cannot be performed in real-time.

The aim is to replace the separate pcps_multithread_acquisition_cc.

TODO: implement the same thing for the pcps_acquisition_sc
This commit is contained in:
Cillian O'Driscoll 2017-08-24 12:32:37 +01:00
parent 3f557eeb41
commit ba3d7bfcd8
8 changed files with 247 additions and 157 deletions
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7
src/algorithms/acquisition/adapters/galileo_e1_pcps_ambiguous_acquisition.cc
View File

@ -56,6 +56,7 @@ GalileoE1PcpsAmbiguousAcquisition::GalileoE1PcpsAmbiguousAcquisition(
fs_in_ = configuration_->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
if_ = configuration_->property(role + ".if", 0);
dump_ = configuration_->property(role + ".dump", false);
blocking_ = configuration_->property(role + ".blocking", true);
doppler_max_ = configuration_->property(role + ".doppler_max", 5000);
sampled_ms_ = configuration_->property(role + ".coherent_integration_time_ms", 4);
@ -91,7 +92,8 @@ GalileoE1PcpsAmbiguousAcquisition::GalileoE1PcpsAmbiguousAcquisition(
item_size_ = sizeof(lv_16sc_t);
acquisition_sc_ = pcps_make_acquisition_sc(sampled_ms_, max_dwells_,
doppler_max_, if_, fs_in_, samples_per_ms, code_length_,
bit_transition_flag_, use_CFAR_algorithm_flag_, dump_, dump_filename_);
bit_transition_flag_, use_CFAR_algorithm_flag_, dump_,
dump_filename_);
DLOG(INFO) << "acquisition(" << acquisition_sc_->unique_id() << ")";
}
@ -100,7 +102,8 @@ GalileoE1PcpsAmbiguousAcquisition::GalileoE1PcpsAmbiguousAcquisition(
item_size_ = sizeof(gr_complex);
acquisition_cc_ = pcps_make_acquisition_cc(sampled_ms_, max_dwells_,
doppler_max_, if_, fs_in_, samples_per_ms, code_length_,
bit_transition_flag_, use_CFAR_algorithm_flag_, dump_, dump_filename_);
bit_transition_flag_, use_CFAR_algorithm_flag_, dump_, blocking_,
dump_filename_);
DLOG(INFO) << "acquisition(" << acquisition_cc_->unique_id() << ")";
}

1
src/algorithms/acquisition/adapters/galileo_e1_pcps_ambiguous_acquisition.h
View File

@ -155,6 +155,7 @@ private:
long fs_in_;
long if_;
bool dump_;
bool blocking_;
std::string dump_filename_;
std::complex<float> * code_;
Gnss_Synchro * gnss_synchro_;

3
src/algorithms/acquisition/adapters/gps_l1_ca_pcps_acquisition.cc
View File

@ -59,6 +59,7 @@ GpsL1CaPcpsAcquisition::GpsL1CaPcpsAcquisition(
fs_in_ = configuration_->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
if_ = configuration_->property(role + ".if", 0);
dump_ = configuration_->property(role + ".dump", false);
blocking_ = configuration_->property(role + ".blocking", true);
doppler_max_ = configuration_->property(role + ".doppler_max", 5000);
sampled_ms_ = configuration_->property(role + ".coherent_integration_time_ms", 1);
@ -94,7 +95,7 @@ GpsL1CaPcpsAcquisition::GpsL1CaPcpsAcquisition(
item_size_ = sizeof(gr_complex);
acquisition_cc_ = pcps_make_acquisition_cc(sampled_ms_, max_dwells_,
doppler_max_, if_, fs_in_, code_length_, code_length_,
bit_transition_flag_, use_CFAR_algorithm_flag_, dump_, dump_filename_);
bit_transition_flag_, use_CFAR_algorithm_flag_, dump_, blocking_, dump_filename_);
DLOG(INFO) << "acquisition(" << acquisition_cc_->unique_id() << ")";
}

1
src/algorithms/acquisition/adapters/gps_l1_ca_pcps_acquisition.h
View File

@ -160,6 +160,7 @@ private:
long fs_in_;
long if_;
bool dump_;
bool blocking_;
std::string dump_filename_;
std::complex<float> * code_;
Gnss_Synchro * gnss_synchro_;

4
src/algorithms/acquisition/adapters/gps_l2_m_pcps_acquisition.cc
View File

@ -59,6 +59,7 @@ GpsL2MPcpsAcquisition::GpsL2MPcpsAcquisition(
fs_in_ = configuration_->property("GNSS-SDR.internal_fs_sps", fs_in_deprecated);
if_ = configuration_->property(role + ".if", 0);
dump_ = configuration_->property(role + ".dump", false);
blocking_ = configuration_->property(role + ".blocking", true);
doppler_max_ = configuration->property(role + ".doppler_max", 5000);
bit_transition_flag_ = configuration_->property(role + ".bit_transition_flag", false);
@ -95,7 +96,8 @@ GpsL2MPcpsAcquisition::GpsL2MPcpsAcquisition(
item_size_ = sizeof(gr_complex);
acquisition_cc_ = pcps_make_acquisition_cc(1, max_dwells_,
doppler_max_, if_, fs_in_, code_length_, code_length_,
bit_transition_flag_, use_CFAR_algorithm_flag_, dump_, dump_filename_);
bit_transition_flag_, use_CFAR_algorithm_flag_, dump_, blocking_,
dump_filename_);
DLOG(INFO) << "acquisition(" << acquisition_cc_->unique_id() << ")";
}

1
src/algorithms/acquisition/adapters/gps_l2_m_pcps_acquisition.h
View File

@ -157,6 +157,7 @@ private:
long fs_in_;
long if_;
bool dump_;
bool blocking_;
std::string dump_filename_;
std::complex<float> * code_;
Gnss_Synchro * gnss_synchro_;

365
src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_cc.cc
View File

@ -50,12 +50,12 @@ pcps_acquisition_cc_sptr pcps_make_acquisition_cc(
unsigned int doppler_max, long freq, long fs_in,
int samples_per_ms, int samples_per_code,
bool bit_transition_flag, bool use_CFAR_algorithm_flag,
bool dump,
bool dump, bool blocking,
std::string dump_filename)
{
return pcps_acquisition_cc_sptr(
new pcps_acquisition_cc(sampled_ms, max_dwells, doppler_max, freq, fs_in, samples_per_ms,
samples_per_code, bit_transition_flag, use_CFAR_algorithm_flag, dump, dump_filename));
samples_per_code, bit_transition_flag, use_CFAR_algorithm_flag, dump, blocking, dump_filename));
}
@ -64,7 +64,7 @@ pcps_acquisition_cc::pcps_acquisition_cc(
unsigned int doppler_max, long freq, long fs_in,
int samples_per_ms, int samples_per_code,
bool bit_transition_flag, bool use_CFAR_algorithm_flag,
bool dump,
bool dump, bool blocking,
std::string dump_filename) :
gr::block("pcps_acquisition_cc",
gr::io_signature::make(1, 1, sizeof(gr_complex) * sampled_ms * samples_per_ms * ( bit_transition_flag ? 2 : 1 )),
@ -129,6 +129,16 @@ pcps_acquisition_cc::pcps_acquisition_cc(
d_gnss_synchro = 0;
d_grid_doppler_wipeoffs = 0;
d_done = false;
d_blocking = blocking;
d_new_data_available = false;
d_worker_active = false;
d_data_buffer = static_cast<gr_complex*>(volk_gnsssdr_malloc(d_fft_size * sizeof(gr_complex), volk_gnsssdr_get_alignment()));
// Start the worker thread and wait for it to acknowledge:
std::thread t1( &pcps_acquisition_cc::acquisition_core, this );
std::swap( d_worker_thread, t1 );
}
@ -153,6 +163,16 @@ pcps_acquisition_cc::~pcps_acquisition_cc()
{
d_dump_file.close();
}
// Let the worker thread know that we are done and then wait to join
{
std::lock_guard<std::mutex> lk( d_mutex );
d_done = true;
d_cond.notify_one();
}
d_worker_thread.join();
volk_gnsssdr_free( d_data_buffer );
}
@ -212,6 +232,10 @@ void pcps_acquisition_cc::init()
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);
}
d_new_data_available = false;
d_done = false;
d_worker_active = false;
}
@ -316,176 +340,217 @@ int pcps_acquisition_cc::general_work(int noutput_items,
case 1:
{
// initialize acquisition algorithm
int doppler;
uint32_t indext = 0;
float magt = 0.0;
const gr_complex *in = reinterpret_cast<const gr_complex *>(input_items[0]);
std::unique_lock<std::mutex> lk( d_mutex );
int effective_fft_size = ( d_bit_transition_flag ? d_fft_size/2 : d_fft_size );
float fft_normalization_factor = static_cast<float>(d_fft_size) * static_cast<float>(d_fft_size);
d_input_power = 0.0;
d_mag = 0.0;
d_sample_counter += d_fft_size; // sample counter
d_well_count++;
DLOG(INFO)<< "Channel: " << d_channel
<< " , doing acquisition of satellite: " << d_gnss_synchro->System << " " << d_gnss_synchro->PRN
<< " ,sample stamp: " << d_sample_counter << ", threshold: "
<< d_threshold << ", doppler_max: " << d_doppler_max
<< ", doppler_step: " << d_doppler_step<<std::endl;
if (d_use_CFAR_algorithm_flag == true)
if( d_worker_active && !d_blocking )
{
d_sample_counter += d_fft_size * ninput_items[0];
consume_each( ninput_items[0] );
}
else
{
if( d_worker_active && d_blocking )
{
// 1- (optional) Compute the input signal power estimation
volk_32fc_magnitude_squared_32f(d_magnitude, in, d_fft_size);
volk_32f_accumulator_s32f(&d_input_power, d_magnitude, d_fft_size);
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++)
{
// 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 == true)
{
// 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 == 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);
}
// 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)
{
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 = d_sample_counter;
// 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)
{
std::stringstream filename;
std::streamsize n = 2 * sizeof(float) * (d_fft_size); // complex file write
filename.str("");
boost::filesystem::path p = d_dump_filename;
filename << p.parent_path().string()
<< boost::filesystem::path::preferred_separator
<< p.stem().string()
<< "_" << d_gnss_synchro->System
<<"_" << d_gnss_synchro->Signal << "_sat_"
<< d_gnss_synchro->PRN << "_doppler_"
<< doppler
<< p.extension().string();
DLOG(INFO) << "Writing ACQ out to " << filename.str();
d_dump_file.open(filename.str().c_str(), std::ios::out | std::ios::binary);
d_dump_file.write(reinterpret_cast<char*>(d_ifft->get_outbuf()), n); //write directly |abs(x)|^2 in this Doppler bin?
d_dump_file.close();
}
d_cond.wait( lk, [&]{ return !this->d_worker_active; } );
}
if (!d_bit_transition_flag)
d_sample_counter += d_fft_size;
if( d_well_count > 0 )
{
if (d_test_statistics > d_threshold)
if (!d_bit_transition_flag)
{
if (d_test_statistics > d_threshold)
{
d_state = 0; // Positive acquisition
d_active = false;
send_positive_acquisition();
}
else if (d_well_count == d_max_dwells)
else if (d_well_count == d_max_dwells)
{
d_state = 0;
d_active = false;
send_negative_acquisition();
}
}
else
{
if (d_well_count == d_max_dwells) // d_max_dwells = 2
}
else
{
if (d_well_count == d_max_dwells) // d_max_dwells = 2
{
if (d_test_statistics > d_threshold)
{
d_state = 0; // Positive acquisition
d_active = false;
send_positive_acquisition();
}
{
d_state = 0; // Positive acquisition
d_active = false;
send_positive_acquisition();
}
else
{
d_state = 0; // Negative acquisition
d_active = false;
send_negative_acquisition();
}
{
d_state = 0; // Negative acquisition
d_active = false;
send_negative_acquisition();
}
}
}
}
consume_each(1);
break;
}
}
if( d_active )
{
memcpy( d_data_buffer, input_items[0], d_fft_size * sizeof( gr_complex ) );
d_new_data_available = true;
d_cond.notify_one();
}
consume_each(1);
} // if worker_active (else)
} // case 1, switch d_state
} // switch d_state
return noutput_items;
}
void pcps_acquisition_cc::acquisition_core( void )
{
d_worker_active = false;
while( 1 )
{
std::unique_lock<std::mutex> lk( d_mutex );
d_cond.wait( lk, [&]{ return this->d_new_data_available or this->d_done; } );
d_worker_active = !d_done;
lk.unlock();
//void pcps_acquisition_cc::forecast (int noutput_items, gr_vector_int &ninput_items_required)
//{
//// COD:
//// For zero-padded case we need one extra code period
//if( d_bit_transition_flag )
//{
//ninput_items_required[0] = noutput_items*(d_samples_per_code * d_max_dwells + d_samples_per_code);
//}
//else
//{
//ninput_items_required[0] = noutput_items*d_fft_size*d_max_dwells;
//}
//}
if( d_done )
{
break;
}
// 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
int effective_fft_size = ( d_bit_transition_flag ? d_fft_size/2 : d_fft_size );
float fft_normalization_factor = static_cast<float>(d_fft_size) * static_cast<float>(d_fft_size);
d_input_power = 0.0;
d_mag = 0.0;
unsigned long int sample_counter = d_sample_counter; // sample counter
d_well_count++;
DLOG(INFO)<< "Channel: " << d_channel
<< " , doing acquisition of satellite: " << d_gnss_synchro->System << " " << d_gnss_synchro->PRN
<< " ,sample stamp: " << sample_counter << ", threshold: "
<< d_threshold << ", doppler_max: " << d_doppler_max
<< ", doppler_step: " << d_doppler_step
<< ", use_CFAR_algorithm_flag: " << ( d_use_CFAR_algorithm_flag ? "true" : "false" )
<<std::endl;
if (d_use_CFAR_algorithm_flag == true)
{
// 1- (optional) Compute the input signal power estimation
volk_32fc_magnitude_squared_32f(d_magnitude, in, d_fft_size);
volk_32f_accumulator_s32f(&d_input_power, d_magnitude, d_fft_size);
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++)
{
// 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 == true)
{
// 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 == 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);
}
// 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)
{
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 = sample_counter;
// 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)
{
std::stringstream filename;
std::streamsize n = 2 * sizeof(float) * (d_fft_size); // complex file write
filename.str("");
boost::filesystem::path p = d_dump_filename;
filename << p.parent_path().string()
<< boost::filesystem::path::preferred_separator
<< p.stem().string()
<< "_" << d_gnss_synchro->System
<<"_" << d_gnss_synchro->Signal << "_sat_"
<< d_gnss_synchro->PRN << "_doppler_"
<< doppler
<< p.extension().string();
DLOG(INFO) << "Writing ACQ out to " << filename.str();
d_dump_file.open(filename.str().c_str(), std::ios::out | std::ios::binary);
d_dump_file.write((char*)d_ifft->get_outbuf(), n); //write directly |abs(x)|^2 in this Doppler bin?
d_dump_file.close();
}
}
lk.lock();
d_worker_active = false;
d_new_data_available = false;
lk.unlock();
d_cond.notify_one();
}
}

22
src/algorithms/acquisition/gnuradio_blocks/pcps_acquisition_cc.h
View File

@ -52,6 +52,9 @@
#include <fstream>
#include <string>
#include <mutex>
#include <thread>
#include <condition_variable>
#include <gnuradio/block.h>
#include <gnuradio/gr_complex.h>
#include <gnuradio/fft/fft.h>
@ -66,7 +69,7 @@ pcps_make_acquisition_cc(unsigned int sampled_ms, unsigned int max_dwells,
unsigned int doppler_max, long freq, long fs_in,
int samples_per_ms, int samples_per_code,
bool bit_transition_flag, bool use_CFAR_algorithm_flag,
bool dump,
bool dump, bool blocking,
std::string dump_filename);
/*!
@ -83,18 +86,20 @@ private:
unsigned int doppler_max, long freq, long fs_in,
int samples_per_ms, int samples_per_code,
bool bit_transition_flag, bool use_CFAR_algorithm_flag,
bool dump,
bool dump, bool blocking,
std::string dump_filename);
pcps_acquisition_cc(unsigned int sampled_ms, unsigned int max_dwells,
unsigned int doppler_max, long freq, long fs_in,
int samples_per_ms, int samples_per_code,
bool bit_transition_flag, bool use_CFAR_algorithm_flag,
bool dump,
bool dump, bool blocking,
std::string dump_filename);
void update_local_carrier(gr_complex* carrier_vector, int correlator_length_samples, float freq);
void acquisition_core( void );
void send_negative_acquisition();
void send_positive_acquisition();
long d_fs_in;
@ -132,6 +137,17 @@ private:
unsigned int d_channel;
std::string d_dump_filename;
std::thread d_worker_thread;
std::mutex d_mutex;
std::condition_variable d_cond;
bool d_done;
bool d_new_data_available;
bool d_worker_active;
bool d_blocking;
gr_complex *d_data_buffer;
public:
/*!
* \brief Default destructor.