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