/////////////////////////////////////////////////////////////////////////////////// // Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany // // written by Christian Daniel // // Copyright (C) 2015-2016, 2018-2019 Edouard Griffiths, F4EXB // // Copyright (C) 2020 Jon Beniston, M7RCE // // // // 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 // // (at your option) any later version. // // // // 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 . // /////////////////////////////////////////////////////////////////////////////////// #ifndef INCLUDE_GOERTZEL_H #define INCLUDE_GOERTZEL_H #include #include "export.h" // Goertzel filter for calculting discrete Fourier transform for a single frequency // Implementation supports non-integer multiples of fundamental frequency, see: // https://asp-eurasipjournals.springeropen.com/track/pdf/10.1186/1687-6180-2012-56.pdf class SDRBASE_API Goertzel { public: Goertzel(double frequency, int sampleRate); void reset(); void filter(double sample); std::complex goertzel(double lastSample); double mag(); double phase(); int size() { return m_sampleCount; } private: double m_s0, m_s1, m_s2; double m_a, m_b; std::complex m_c, m_z; int m_sampleCount; }; #endif // INCLUDE_GOERTZEL_H