132 lines
3.7 KiB
C
132 lines
3.7 KiB
C
/*
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* cxvec_math.h
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*
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* Complex vectors math and signal processing
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*
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* Copyright (C) 2011 Sylvain Munaut <tnt@246tNt.com>
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*
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* All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef __OSMO_DSP_CXVEC_MATH_H__
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#define __OSMO_DSP_CXVEC_MATH_H__
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/*! \defgroup cxvec_math Complex vectors math and signal processing
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* \ingroup cxvec
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* @{
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*/
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/*! \file cxvec_math.h
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* \brief Osmocom Complex vectors math header
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*/
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#include <complex.h>
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#include <math.h>
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#include <osmocom/dsp/cxvec.h>
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/* Generic math stuff */
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#define M_PIf (3.14159265358979323846264338327f) /*!< \brief PI value float */
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/*! \brief Unnormalized sinc function
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* \param[in] x Value for which to compute the sinc function.
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* \returns The sinc(x) value
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*
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* The function is defined as \f$\frac{\sin(x)}{x}\f$
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*/
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static inline float
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osmo_sinc(float x)
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{
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if ((x >= 0.01f) || (x <= -0.01f)) return (sinf(x)/x);
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return 1.0f;
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}
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/*! \brief Squared norm of a given complex
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* \param[in] c Complex number for which to compute the squared norm
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* \returns \f$|c|^2\f$
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*/
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static inline float
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osmo_normsqf(float complex c)
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{
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return crealf(c) * crealf(c) + cimagf(c) * cimagf(c);
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}
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/* Complex vector math */
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struct osmo_cxvec *
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osmo_cxvec_scale(const struct osmo_cxvec *in, float complex scale,
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struct osmo_cxvec *out);
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struct osmo_cxvec *
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osmo_cxvec_rotate(const struct osmo_cxvec *in, float freq_shift,
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struct osmo_cxvec *out);
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struct osmo_cxvec *
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osmo_cxvec_delay(const struct osmo_cxvec *v, float delay,
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struct osmo_cxvec *out);
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/*! \brief Various possible types of convolution span */
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enum osmo_cxvec_conv_type {
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/*! \brief Full span (every possible overlap of f onto g) */
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CONV_FULL_SPAN,
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/*! \brief Every possible full overlap of f onto g */
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CONV_OVERLAP_ONLY,
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/*! \brief Center f sequence on every g sample */
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CONV_NO_DELAY,
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};
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struct osmo_cxvec *
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osmo_cxvec_convolve(const struct osmo_cxvec *f, const struct osmo_cxvec *g,
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enum osmo_cxvec_conv_type type, struct osmo_cxvec *out);
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struct osmo_cxvec *
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osmo_cxvec_correlate(const struct osmo_cxvec *f, const struct osmo_cxvec *g,
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int g_corr_step, struct osmo_cxvec *out);
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float complex
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osmo_cxvec_interpolate_point(const struct osmo_cxvec *cv, float pos);
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int
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osmo_cxvec_peaks_scan(const struct osmo_cxvec *cv, int *peaks_idx, int N);
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/*! \brief Various possible peak finding algorithms */
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enum osmo_cxvec_peak_alg {
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/*! \brief Weigthed position for the max pwr window */
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PEAK_WEIGH_WIN,
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/*! \brief Weighted position of the peak centered window */
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PEAK_WEIGH_WIN_CENTER,
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/*! \brief Early-Late balancing around peak */
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PEAK_EARLY_LATE,
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};
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float
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osmo_cxvec_peak_energy_find(const struct osmo_cxvec *cv, int win_size,
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enum osmo_cxvec_peak_alg alg,
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float complex *peak_val_p);
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struct osmo_cxvec *
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osmo_cxvec_sig_normalize(const struct osmo_cxvec *sig,
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int decim, float freq_shift,
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struct osmo_cxvec *out);
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/*! @} */
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#endif /* __OSMO_DSP_CXVEC_MATH_H__ */
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