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			106 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			106 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
|  | ///////////////////////////////////////////////////////////////////////////////////
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|  | // Copyright (C) 2018 Edouard Griffiths, F4EXB                                   //
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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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|  | 
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|  | #ifndef SDRBASE_DSP_AUTOCORRECTOR_H_
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|  | #define SDRBASE_DSP_AUTOCORRECTOR_H_
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|  | 
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|  | #include "util/movingaverage.h"
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|  | 
 | ||
|  | template<typename T> | ||
|  | class AutoCorrector | ||
|  | { | ||
|  | public: | ||
|  |     AutoCorrector(qint32 intBits); | ||
|  |     void process(const T& inreal, const T& inimag, qint32& outreal, qint32& outimag); | ||
|  |     void process(qint32& xreal, qint32& ximag); | ||
|  |     void setIQCorrection(bool iqCorrection) { m_iqCorrection = iqCorrection; } | ||
|  | private: | ||
|  |     bool m_iqCorrection; | ||
|  |     float m_scalef; | ||
|  |     MovingAverageUtil<int32_t, int64_t, 1024> m_iBeta; | ||
|  |     MovingAverageUtil<int32_t, int64_t, 1024> m_qBeta; | ||
|  |     MovingAverageUtil<float, double, 128> m_avgII; | ||
|  |     MovingAverageUtil<float, double, 128> m_avgIQ; | ||
|  |     MovingAverageUtil<float, double, 128> m_avgII2; | ||
|  |     MovingAverageUtil<float, double, 128> m_avgQQ2; | ||
|  |     MovingAverageUtil<double, double, 128> m_avgPhi; | ||
|  |     MovingAverageUtil<double, double, 128> m_avgAmp; | ||
|  | }; | ||
|  | 
 | ||
|  | template<typename T> | ||
|  | AutoCorrector<T>::AutoCorrector(qint32 intBits) : | ||
|  |     m_iqCorrection(false), | ||
|  |     m_scalef((float) (1<<(intBits-1))) | ||
|  | { | ||
|  | } | ||
|  | 
 | ||
|  | template<typename T> | ||
|  | void AutoCorrector<T>::process(const T& inreal, const T& inimag, qint32& outreal, qint32& outimag) | ||
|  | { | ||
|  |     outreal = inreal; | ||
|  |     outimag = inimag; | ||
|  |     process(outreal, outimag); | ||
|  | } | ||
|  | 
 | ||
|  | template<typename T> | ||
|  | void AutoCorrector<T>::process(qint32& xreal, qint32& ximag) | ||
|  | { | ||
|  |     m_iBeta(xreal); | ||
|  |     m_qBeta(ximag); | ||
|  | 
 | ||
|  |     if (m_iqCorrection) | ||
|  |     { | ||
|  |         // DC correction and conversion
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|  |         float xi = (xreal - (int32_t) m_iBeta) / m_scalef; | ||
|  |         float xq = (ximag - (int32_t) m_qBeta) / m_scalef; | ||
|  | 
 | ||
|  |         // phase imbalance
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|  |         m_avgII(xi*xi); // <I", I">
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|  |         m_avgIQ(xi*xq); // <I", Q">
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|  | 
 | ||
|  | 
 | ||
|  |         if (m_avgII.asDouble() != 0) { | ||
|  |             m_avgPhi(m_avgIQ.asDouble()/m_avgII.asDouble()); | ||
|  |         } | ||
|  | 
 | ||
|  |         float yi = xi - m_avgPhi.asDouble()*xq; | ||
|  |         float yq = xq; | ||
|  | 
 | ||
|  |         // amplitude I/Q imbalance
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|  |         m_avgII2(yi*yi); // <I, I>
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|  |         m_avgQQ2(yq*yq); // <Q, Q>
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|  | 
 | ||
|  |         if (m_avgQQ2.asDouble() != 0) { | ||
|  |             m_avgAmp(sqrt(m_avgII2.asDouble() / m_avgQQ2.asDouble())); | ||
|  |         } | ||
|  | 
 | ||
|  |         // final correction
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|  |         float zi = yi; | ||
|  |         float zq = m_avgAmp.asDouble() * yq; | ||
|  | 
 | ||
|  |         // convert and store
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|  |         xreal = zi * m_scalef; | ||
|  |         ximag = zq * m_scalef; | ||
|  |     } | ||
|  |     else | ||
|  |     { | ||
|  |         xreal -= (int32_t) m_iBeta; | ||
|  |         ximag -= (int32_t) m_qBeta; | ||
|  |     } | ||
|  | } | ||
|  | 
 | ||
|  | #endif /* SDRBASE_DSP_AUTOCORRECTOR_H_ */
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