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/*!
* \ file galileo_e5b_pcps_acquisition_fpga . cc
* \ brief Adapts a PCPS acquisition block to an AcquisitionInterface for
* Galileo E5b data and pilot Signals for the FPGA
* \ author Piyush Gupta , 2020. piyush04111999 @ gmail . com
* \ note Code added as part of GSoC 2020 Program .
*
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* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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*
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* GNSS - SDR is a Global Navigation Satellite System software - defined receiver .
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* This file is part of GNSS - SDR .
*
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* Copyright ( C ) 2010 - 2022 ( see AUTHORS file for a list of contributors )
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* SPDX - License - Identifier : GPL - 3.0 - or - later
*
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* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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*/
# include "galileo_e5b_pcps_acquisition_fpga.h"
# include "Galileo_E5b.h"
# include "configuration_interface.h"
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# include "galileo_e5_signal_replica.h"
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# include "gnss_sdr_fft.h"
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# include "gnss_sdr_flags.h"
# include <glog/logging.h>
# include <gnuradio/gr_complex.h> // for gr_complex
# include <volk/volk.h> // for volk_32fc_conjugate_32fc
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# include <algorithm> // for copy_n
# include <cmath> // for abs, pow, floor
# include <complex> // for complex
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GalileoE5bPcpsAcquisitionFpga : : GalileoE5bPcpsAcquisitionFpga ( const ConfigurationInterface * configuration ,
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const std : : string & role ,
unsigned int in_streams ,
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unsigned int out_streams )
: gnss_synchro_ ( nullptr ) ,
role_ ( role ) ,
doppler_center_ ( 0 ) ,
channel_ ( 0 ) ,
doppler_step_ ( 0 ) ,
in_streams_ ( in_streams ) ,
out_streams_ ( out_streams ) ,
acq_pilot_ ( configuration - > property ( role + " .acquire_pilot " , false ) ) ,
acq_iq_ ( configuration - > property ( role + " .acquire_iq " , false ) )
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{
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acq_parameters_ . SetFromConfiguration ( configuration , role_ , fpga_downsampling_factor , fpga_buff_num , fpga_blk_exp , GALILEO_E5B_CODE_CHIP_RATE_CPS , GALILEO_E5B_CODE_LENGTH_CHIPS ) ;
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if ( FLAGS_doppler_max ! = 0 )
{
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acq_parameters_ . doppler_max = FLAGS_doppler_max ;
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}
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doppler_max_ = acq_parameters_ . doppler_max ;
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doppler_step_ = static_cast < unsigned int > ( acq_parameters_ . doppler_step ) ;
fs_in_ = acq_parameters_ . fs_in ;
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uint32_t code_length = acq_parameters_ . code_length ;
uint32_t nsamples_total = acq_parameters_ . samples_per_code ;
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// compute all the GALILEO E5b PRN Codes (this is done only once in the class constructor in order to avoid re-computing the PRN codes every time
// a channel is assigned)
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auto fft_if = gnss_fft_fwd_make_unique ( nsamples_total ) ; // Direct FFT
volk_gnsssdr : : vector < std : : complex < float > > code ( nsamples_total ) ; // Buffer for local code
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volk_gnsssdr : : vector < std : : complex < float > > fft_codes_padded ( nsamples_total ) ;
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d_all_fft_codes_ = volk_gnsssdr : : vector < uint32_t > ( nsamples_total * GALILEO_E5B_NUMBER_OF_CODES ) ; // memory containing all the possible fft codes for PRN 0 to 32
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if ( acq_iq_ )
{
acq_pilot_ = false ;
}
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float max ; // temporary maxima search
int32_t tmp ;
int32_t tmp2 ;
int32_t local_code ;
int32_t fft_data ;
for ( uint32_t PRN = 1 ; PRN < = GALILEO_E5B_NUMBER_OF_CODES ; PRN + + )
{
std : : array < char , 3 > signal_ ;
signal_ [ 0 ] = ' 7 ' ;
signal_ [ 2 ] = ' \0 ' ;
if ( acq_iq_ )
{
signal_ [ 1 ] = ' X ' ;
}
else if ( acq_pilot_ )
{
signal_ [ 1 ] = ' Q ' ;
}
else
{
signal_ [ 1 ] = ' I ' ;
}
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galileo_e5_b_code_gen_complex_sampled ( code , PRN , signal_ , fs_in_ , 0 ) ;
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for ( uint32_t s = code_length ; s < 2 * code_length ; s + + )
{
code [ s ] = code [ s - code_length ] ;
}
// fill in zero padding
for ( uint32_t s = 2 * code_length ; s < nsamples_total ; s + + )
{
code [ s ] = std : : complex < float > ( 0.0 , 0.0 ) ;
}
std : : copy_n ( code . data ( ) , nsamples_total , fft_if - > get_inbuf ( ) ) ; // copy to FFT buffer
fft_if - > execute ( ) ; // Run the FFT of local code
volk_32fc_conjugate_32fc ( fft_codes_padded . data ( ) , fft_if - > get_outbuf ( ) , nsamples_total ) ; // conjugate values
max = 0 ; // initialize maximum value
for ( uint32_t i = 0 ; i < nsamples_total ; i + + ) // search for maxima
{
if ( std : : abs ( fft_codes_padded [ i ] . real ( ) ) > max )
{
max = std : : abs ( fft_codes_padded [ i ] . real ( ) ) ;
}
if ( std : : abs ( fft_codes_padded [ i ] . imag ( ) ) > max )
{
max = std : : abs ( fft_codes_padded [ i ] . imag ( ) ) ;
}
}
// map the FFT to the dynamic range of the fixed point values an copy to buffer containing all FFTs
// and package codes in a format that is ready to be written to the FPGA
for ( uint32_t i = 0 ; i < nsamples_total ; i + + )
{
tmp = static_cast < int32_t > ( floor ( fft_codes_padded [ i ] . real ( ) * ( pow ( 2 , quant_bits_local_code - 1 ) - 1 ) / max ) ) ;
tmp2 = static_cast < int32_t > ( floor ( fft_codes_padded [ i ] . imag ( ) * ( pow ( 2 , quant_bits_local_code - 1 ) - 1 ) / max ) ) ;
local_code = ( tmp & select_lsbits ) | ( ( tmp2 * shl_code_bits ) & select_msbits ) ; // put together the real part and the imaginary part
fft_data = local_code & select_all_code_bits ;
d_all_fft_codes_ [ i + ( nsamples_total * ( PRN - 1 ) ) ] = fft_data ;
}
}
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acq_parameters_ . all_fft_codes = d_all_fft_codes_ . data ( ) ;
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acquisition_fpga_ = pcps_make_acquisition_fpga ( acq_parameters_ ) ;
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if ( in_streams_ > 1 )
{
LOG ( ERROR ) < < " This implementation only supports one input stream " ;
}
if ( out_streams_ > 0 )
{
LOG ( ERROR ) < < " This implementation does not provide an output stream " ;
}
}
void GalileoE5bPcpsAcquisitionFpga : : stop_acquisition ( )
{
// this command causes the SW to reset the HW.
acquisition_fpga_ - > reset_acquisition ( ) ;
}
void GalileoE5bPcpsAcquisitionFpga : : set_threshold ( float threshold )
{
DLOG ( INFO ) < < " Channel " < < channel_ < < " Threshold = " < < threshold ;
acquisition_fpga_ - > set_threshold ( threshold ) ;
}
void GalileoE5bPcpsAcquisitionFpga : : set_doppler_max ( unsigned int doppler_max )
{
doppler_max_ = doppler_max ;
acquisition_fpga_ - > set_doppler_max ( doppler_max_ ) ;
}
void GalileoE5bPcpsAcquisitionFpga : : set_doppler_step ( unsigned int doppler_step )
{
doppler_step_ = doppler_step ;
acquisition_fpga_ - > set_doppler_step ( doppler_step_ ) ;
}
void GalileoE5bPcpsAcquisitionFpga : : set_doppler_center ( int doppler_center )
{
doppler_center_ = doppler_center ;
acquisition_fpga_ - > set_doppler_center ( doppler_center_ ) ;
}
void GalileoE5bPcpsAcquisitionFpga : : set_gnss_synchro ( Gnss_Synchro * gnss_synchro )
{
gnss_synchro_ = gnss_synchro ;
acquisition_fpga_ - > set_gnss_synchro ( gnss_synchro_ ) ;
}
signed int GalileoE5bPcpsAcquisitionFpga : : mag ( )
{
return acquisition_fpga_ - > mag ( ) ;
}
void GalileoE5bPcpsAcquisitionFpga : : init ( )
{
acquisition_fpga_ - > init ( ) ;
}
void GalileoE5bPcpsAcquisitionFpga : : set_local_code ( )
{
acquisition_fpga_ - > set_local_code ( ) ;
}
void GalileoE5bPcpsAcquisitionFpga : : reset ( )
{
acquisition_fpga_ - > set_active ( true ) ;
}
void GalileoE5bPcpsAcquisitionFpga : : set_state ( int state )
{
acquisition_fpga_ - > set_state ( state ) ;
}
void GalileoE5bPcpsAcquisitionFpga : : connect ( gr : : top_block_sptr top_block )
{
if ( top_block )
{
/* top_block is not null */
} ;
// Nothing to connect
}
void GalileoE5bPcpsAcquisitionFpga : : disconnect ( gr : : top_block_sptr top_block )
{
if ( top_block )
{
/* top_block is not null */
} ;
// Nothing to disconnect
}
gr : : basic_block_sptr GalileoE5bPcpsAcquisitionFpga : : get_left_block ( )
{
return nullptr ;
}
gr : : basic_block_sptr GalileoE5bPcpsAcquisitionFpga : : get_right_block ( )
{
return nullptr ;
}