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										 |  |  | ///////////////////////////////////////////////////////////////////////////////////
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										 |  |  | // Copyright (C) 2012 maintech GmbH, Otto-Hahn-Str. 15, 97204 Hoechberg, Germany //
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							|  |  |  | // written by Christian Daniel                                                   //
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							|  |  |  | // Copyright (C) 2015-2016, 2018-2019 Edouard Griffiths, F4EXB <f4exb06@gmail.com> //
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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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										 |  |  | // (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 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 INCLUDE_DSP_FILTERRC_H_
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							|  |  |  | #define INCLUDE_DSP_FILTERRC_H_
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							|  |  |  | #include "dsp/dsptypes.h"
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										 |  |  | #include "export.h"
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							|  |  |  | /** First order low-pass IIR filter for real-valued signals. */ | 
					
						
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										 |  |  | class SDRBASE_API LowPassFilterRC | 
					
						
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										 |  |  | { | 
					
						
							|  |  |  | public: | 
					
						
							|  |  |  | 
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							|  |  |  |     /**
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							|  |  |  |      * Construct 1st order low-pass IIR filter. | 
					
						
							|  |  |  |      * | 
					
						
							|  |  |  |      * timeconst :: RC time constant in seconds (1 / (2 * PI * cutoff_freq) | 
					
						
							|  |  |  |      */ | 
					
						
							|  |  |  |     LowPassFilterRC(Real timeconst); | 
					
						
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							|  |  |  |     /**
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							|  |  |  |      * Reconfigure filter with new time constant | 
					
						
							|  |  |  |      */ | 
					
						
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										 |  |  |     void configure(Real timeconst); | 
					
						
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							|  |  |  |     /** Process samples. */ | 
					
						
							|  |  |  |     void process(const Real& sample_in, Real& sample_out); | 
					
						
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							|  |  |  | private: | 
					
						
							|  |  |  |     Real m_timeconst; | 
					
						
							|  |  |  |     Real m_y1; | 
					
						
							|  |  |  |     Real m_a1; | 
					
						
							|  |  |  |     Real m_b0; | 
					
						
							|  |  |  | }; | 
					
						
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							|  |  |  | /** First order high-pass IIR filter for real-valued signals. */ | 
					
						
							|  |  |  | class SDRBASE_API HighPassFilterRC | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | public: | 
					
						
							|  |  |  | 
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							|  |  |  |     /**
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							|  |  |  |      * Construct 1st order high-pass IIR filter. | 
					
						
							|  |  |  |      * | 
					
						
							|  |  |  |      * timeconst :: RC time constant in seconds (1 / (2 * PI * cutoff_freq) | 
					
						
							|  |  |  |      */ | 
					
						
							|  |  |  |     HighPassFilterRC(Real timeconst); | 
					
						
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							|  |  |  |     /**
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							|  |  |  |      * Reconfigure filter with new time constant | 
					
						
							|  |  |  |      */ | 
					
						
							|  |  |  |     void configure(Real timeconst); | 
					
						
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							|  |  |  |     /** Process samples. */ | 
					
						
							|  |  |  |     void process(const Real& sample_in, Real& sample_out); | 
					
						
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							|  |  |  | private: | 
					
						
							|  |  |  |     Real m_timeconst; | 
					
						
							|  |  |  |     Real m_y1; | 
					
						
							|  |  |  |     Real m_a1; | 
					
						
							|  |  |  |     Real m_b0; | 
					
						
							|  |  |  | }; | 
					
						
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							|  |  |  | #endif /* INCLUDE_DSP_FILTERRC_H_ */
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