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gnss-sdr/src/algorithms/libs/nco_lib.cc
2016-01-10 22:21:31 +01:00

107 lines
3.4 KiB
C++

/*!
* \file nco_lib.cc
* \brief A set of Numeric Controlled Oscillator (NCO) functions to generate the carrier wipeoff signal,
* regardless of system used
*
* \author Javier Arribas 2012, jarribas(at)cttc.es
*
* Detailed description of the file here if needed.
*
* -------------------------------------------------------------------------
*
* 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 "nco_lib.h"
#include <cmath>
void fxp_nco(std::complex<float> *dest, int n_samples, float start_phase_rad, float phase_step_rad)
{
int phase_rad_i;
phase_rad_i = gr::fxpt::float_to_fixed(start_phase_rad);
int phase_step_rad_i;
phase_step_rad_i = gr::fxpt::float_to_fixed(phase_step_rad);
float sin_f,cos_f;
for(int i = 0; i < n_samples; i++)
{
//using temp variables
gr::fxpt::sincos(-phase_rad_i,&sin_f,&cos_f);
dest[i] = gr_complex(cos_f, sin_f);
phase_rad_i += phase_step_rad_i;
}
}
void fxp_nco_cpyref(std::complex<float> *dest, int n_samples, float start_phase_rad, float phase_step_rad)
{
int phase_rad_i;
phase_rad_i = gr::fxpt::float_to_fixed(start_phase_rad);
int phase_step_rad_i;
phase_step_rad_i = gr::fxpt::float_to_fixed(phase_step_rad);
float* vector_cpx;
vector_cpx = (float*)dest;
for(int i = 0; i < n_samples; i++)
{
//using references (maybe it can be a problem for c++11 ?)
//gr_fxpt::sincos(phase_rad_i,&d_carr_sign[i].imag(),&d_carr_sign[i].real());
gr::fxpt::sincos(-phase_rad_i, &vector_cpx[i*2+1], &vector_cpx[i*2]);
phase_rad_i += phase_step_rad_i;
}
}
void fxp_nco_IQ_split(float* I, float* Q , int n_samples,float start_phase_rad, float phase_step_rad)
{
int phase_rad_i;
phase_rad_i = gr::fxpt::float_to_fixed(start_phase_rad);
int phase_step_rad_i;
phase_step_rad_i = gr::fxpt::float_to_fixed(phase_step_rad);
float sin_f,cos_f;
for(int i = 0; i < n_samples; i++)
{
gr::fxpt::sincos(-phase_rad_i,&sin_f,&cos_f);
I[i] = cos_f;
Q[i] = sin_f;
phase_rad_i += phase_step_rad_i;
}
}
void std_nco(std::complex<float> *dest, int n_samples, float start_phase_rad, float phase_step_rad)
{
float phase_rad;
phase_rad = start_phase_rad;
for(int i = 0; i < n_samples; i++)
{
// Using std::cos and std::sin
dest[i] = gr_complex(std::cos(phase_rad), -std::sin(phase_rad));
phase_rad = phase_rad+phase_step_rad;
}
}