gnss-sdr/src/algorithms/tracking/libs/cpu_multicorrelator_16sc.cc

195 lines
6.7 KiB
C++

/*!
* \file cpu_multicorrelator_16sc.cc
* \brief High optimized CPU vector multiTAP correlator class
* \authors <ul>
* <li> Javier Arribas, 2015. jarribas(at)cttc.es
* </ul>
*
* Class that implements a high optimized vector multiTAP correlator class for CPUs
*
* -------------------------------------------------------------------------
*
* Copyright (C) 2010-2015 (see AUTHORS file for a list of contributors)
*
* GNSS-SDR is a software defined Global Navigation
* Satellite Systems receiver
*
* This file is part of GNSS-SDR.
*
* GNSS-SDR is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GNSS-SDR is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GNSS-SDR. If not, see <http://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#include "cpu_multicorrelator_16sc.h"
#include <cmath>
#include <iostream>
#include <gnuradio/fxpt.h> // fixed point sine and cosine
#define LV_HAVE_GENERIC
#define LV_HAVE_SSE2
#include "volk_gnsssdr_16ic_x2_dot_prod_16ic.h"
#include "volk_gnsssdr_16ic_x2_multiply_16ic.h"
#include "volk_gnsssdr_16ic_resampler_16ic.h"
#include "volk_gnsssdr_16ic_xn_resampler_16ic_xn.h"
#include "volk_gnsssdr_16ic_xn_dot_prod_16ic_xn.h"
bool cpu_multicorrelator_16sc::init(
int max_signal_length_samples,
int n_correlators
)
{
// ALLOCATE MEMORY FOR INTERNAL vectors
size_t size = max_signal_length_samples * sizeof(lv_16sc_t);
// NCO signal
d_nco_in = static_cast<lv_16sc_t*>(volk_malloc(size, volk_get_alignment()));
// Doppler-free signal
d_sig_doppler_wiped = static_cast<lv_16sc_t*>(volk_malloc(size, volk_get_alignment()));
d_local_codes_resampled = new lv_16sc_t*[n_correlators];
for (int n = 0; n < n_correlators; n++)
{
d_local_codes_resampled[n] = static_cast<lv_16sc_t*>(volk_malloc(size, volk_get_alignment()));
}
d_n_correlators = n_correlators;
return true;
}
bool cpu_multicorrelator_16sc::set_local_code_and_taps(
int code_length_chips,
const lv_16sc_t* local_code_in,
float *shifts_chips
)
{
d_local_code_in = local_code_in;
d_shifts_chips = shifts_chips;
d_code_length_chips = code_length_chips;
return true;
}
bool cpu_multicorrelator_16sc::set_input_output_vectors(lv_16sc_t* corr_out, const lv_16sc_t* sig_in)
{
// Save CPU pointers
d_sig_in = sig_in;
d_corr_out = corr_out;
return true;
}
void cpu_multicorrelator_16sc::update_local_code(int correlator_length_samples,float rem_code_phase_chips, float code_phase_step_chips)
{
float *tmp_code_phases_chips;
tmp_code_phases_chips=static_cast<float*>(volk_malloc(d_n_correlators*sizeof(float), volk_get_alignment()));
for (int n=0;n<d_n_correlators;n++)
{
tmp_code_phases_chips[n]=d_shifts_chips[n]-rem_code_phase_chips;
}
volk_gnsssdr_16ic_xn_resampler_16ic_xn_sse2(d_local_codes_resampled,
d_local_code_in,
tmp_code_phases_chips,
code_phase_step_chips,
correlator_length_samples,
d_code_length_chips,
d_n_correlators);
volk_free(tmp_code_phases_chips);
// float local_code_chip_index;
// for (int current_correlator_tap = 0; current_correlator_tap < d_n_correlators; current_correlator_tap++)
// {
// for (int n = 0; n < correlator_length_samples; n++)
// {
// // resample code for current tap
// local_code_chip_index = std::fmod(code_phase_step_chips*static_cast<float>(n)+ d_shifts_chips[current_correlator_tap] - rem_code_phase_chips, d_code_length_chips);
// //Take into account that in multitap correlators, the shifts can be negative!
// if (local_code_chip_index < 0.0) local_code_chip_index += d_code_length_chips;
// d_local_codes_resampled[current_correlator_tap][n] = d_local_code_in[static_cast<int>(round(local_code_chip_index))];
// }
// }
}
void cpu_multicorrelator_16sc::update_local_carrier(int correlator_length_samples, float rem_carr_phase_rad, float phase_step_rad)
{
float sin_f, cos_f;
int phase_step_rad_i = gr::fxpt::float_to_fixed(phase_step_rad);
int phase_rad_i = gr::fxpt::float_to_fixed(rem_carr_phase_rad);
for(int i = 0; i < correlator_length_samples; i++)
{
gr::fxpt::sincos(phase_rad_i, &sin_f, &cos_f);
d_nco_in[i] = lv_16sc_t((short int)(cos_f*2.0), (short int)(-sin_f*2.0));
phase_rad_i += phase_step_rad_i;
}
}
bool cpu_multicorrelator_16sc::Carrier_wipeoff_multicorrelator_resampler(
float rem_carrier_phase_in_rad,
float phase_step_rad,
float rem_code_phase_chips,
float code_phase_step_chips,
int signal_length_samples)
{
update_local_carrier(signal_length_samples, rem_carrier_phase_in_rad, phase_step_rad);
//std::cout<<"d_nco_in 16sc="<<d_nco_in[23]<<std::endl;
volk_gnsssdr_16ic_x2_multiply_16ic_a_sse2(d_sig_doppler_wiped,d_sig_in,d_nco_in,signal_length_samples);
//std::cout<<"d_sig_doppler_wiped 16sc="<<d_sig_doppler_wiped[23]<<std::endl;
update_local_code(signal_length_samples,rem_code_phase_chips, code_phase_step_chips);
volk_gnsssdr_16ic_xn_dot_prod_16ic_xn_a_sse2(d_corr_out, d_sig_doppler_wiped, (const lv_16sc_t**)d_local_codes_resampled,signal_length_samples,d_n_correlators);
//for (int current_correlator_tap = 0; current_correlator_tap < d_n_correlators; current_correlator_tap++)
// {
// volk_gnsssdr_16ic_x2_dot_prod_16ic_a_sse2(&d_corr_out[current_correlator_tap], d_sig_doppler_wiped, d_local_codes_resampled[current_correlator_tap],signal_length_samples);
// }
return true;
}
cpu_multicorrelator_16sc::cpu_multicorrelator_16sc()
{
d_sig_in = NULL;
d_nco_in = NULL;
d_sig_doppler_wiped = NULL;
d_local_code_in = NULL;
d_shifts_chips = NULL;
d_corr_out = NULL;
d_local_codes_resampled = NULL;
d_code_length_chips = 0;
d_n_correlators = 0;
}
bool cpu_multicorrelator_16sc::free()
{
// Free memory
if (d_sig_doppler_wiped != NULL) volk_free(d_sig_doppler_wiped);
if (d_nco_in != NULL) volk_free(d_nco_in);
for (int n = 0; n < d_n_correlators; n++)
{
volk_free(d_local_codes_resampled[n]);
}
delete d_local_codes_resampled;
return true;
}