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sdrangel/sdrbase/dsp/fftcorr.h

58 lines
2.7 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2018 F4EXB //
// written by Edouard Griffiths //
// //
// FFT based cross correlation //
// //
// See: http://liquidsdr.org/blog/pll-howto/ //
// Fixed filter registers saturation //
// Added order for PSK locking. This brilliant idea actually comes from this //
// post: https://www.dsprelated.com/showthread/comp.dsp/36356-1.php //
// //
// This program 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 as version 3 of the License, or //
// //
// This program 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 V3 for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
///////////////////////////////////////////////////////////////////////////////////
#ifndef SDRBASE_DSP_FFTCORR_H_
#define SDRBASE_DSP_FFTCORR_H_
#include <complex>
#include "gfft.h"
#include "export.h"
class SDRBASE_API fftcorr {
public:
typedef std::complex<float> cmplx;
fftcorr(int len);
~fftcorr();
int run(const cmplx& inA, const cmplx* inB, cmplx **out); //!< if inB = 0 then run auto-correlation
const cmplx& run(const cmplx& inA, const cmplx* inB);
private:
void init_fft();
int flen; //!< FFT length
int flen2; //!< half FFT length
g_fft<float> *fftA;
g_fft<float> *fftB;
cmplx *dataA; // from A input
cmplx *dataB; // from B input
cmplx *dataBj; // conjugate of B
cmplx *dataP; // product of A with conjugate of B
int inptrA;
int inptrB;
int outptr;
};
#endif /* SDRBASE_DSP_FFTCORR_H_ */