- initial version

git-svn-id: http://moon:8086/svn/software/trunk/libsrc/cpp@90 b431acfa-c32f-4a4a-93f1-934dc6c82436
2014-12-20 17:56:16 +00:00
commit b0490ad5f2
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+/* 
+ * File:   Equalizer.hpp
+ * Author: jens
+ *
+ * Created on 20. Dezember 2014, 09:24
+ */
+
+#ifndef EQUALIZER_HPP
+#define	EQUALIZER_HPP
+
+#include "Vector.hpp"
+#include "FirComplex.hpp"
+
+namespace Radio
+{
+namespace Equalizer
+{
+
+class AEqualizer : public FirComplex
+{
+public:
+	AEqualizer(uint32_t numTaps)
+	: FirComplex(numTaps)
+	, m_w(numTaps)
+	{
+		
+	}
+	
+	virtual ~AEqualizer() {}
+	
+	void setNumTaps(uint32_t numTaps)
+	{
+		FirComplex::setNumTaps(numTaps);
+		m_w.resize(numTaps);
+	}
+	
+	void setUnit(uint32_t delay)
+	{
+		m_w.setZero();
+		m_w(delay) = ComplexScalar(1, 0);
+	}
+
+	const CVec& getWeights()
+	{
+		return m_w;
+	}
+
+	const AEqualizer& operator=(const AEqualizer &rhs)
+	{
+		this->m_w = rhs.m_w;
+		return *this;
+	}
+	
+protected:
+	CVec m_w;
+
+};
+
+class Lms : public AEqualizer
+{
+public:
+	Lms(uint32_t numTaps)
+	: AEqualizer(numTaps)
+	{
+		
+	}
+	~Lms()
+	{
+		
+	}
+
+	void update(ComplexScalar const &e, RealScalar const &mu)
+	{
+		m_w += m_x * conj(e) * mu;
+	}
+	
+private:
+};
+	
+class Cma : public Lms
+{
+public: 
+	Cma(uint32_t numTaps=0)
+	: Lms(numTaps)
+	, m_xLast(0)
+	, m_power(0)
+	{
+	}
+	
+	void init(uint32_t numTaps)
+	{
+		setNumTaps(numTaps);
+	}
+	
+	ComplexScalar process(ComplexScalar const &x)
+	{
+		RealScalar x1, x2;
+		
+		x1 = abs(x);
+		x2 = abs(m_x[m_numTaps-1]);
+		m_power = max(RealScalar(0), m_power + (x1*x1 - m_xLast));
+		m_xLast = x2*x2;		
+		
+		FirComplex::feed(x);
+		return FirComplex::process(m_w);
+	}
+	
+	// Proakis: page 698
+	void trainGodard(ComplexScalar const &sym_s_eq, RealScalar const &mag_h, RealScalar R2, RealScalar mu)
+	{
+		ComplexScalar d;
+		ComplexScalar e;
+		RealScalar mag_s, t;
+
+		mag_s = abs(sym_s_eq);
+
+		t = (RealScalar)((mag_h + R2*mag_s - mag_s*mag_s*mag_s)/(1E-4+mag_h));
+		d = sym_s_eq * t;
+
+		e = d - sym_s_eq;
+		mu /= (1+m_power);
+		
+		Lms::update(e, mu);
+	}
+
+	// "Sliced Multi-modulus Blind Equalization Algorithm",
+	// ETRI Journal, Volume 27, Number 3, June 2005,
+	// Shafayat Abrar and Roy A. Axford Jr.
+	void trainMma(ComplexScalar const &sym_s_eq, ComplexScalar const &R, RealScalar mu)
+	{
+		ComplexScalar e(sym_s_eq.real()*(R.real() - sym_s_eq.real()*sym_s_eq.real()), sym_s_eq.imag()*(R.imag() - sym_s_eq.imag()*sym_s_eq.imag()));
+
+		mu /= (1+m_power);
+		Lms::update(e, mu);
+	}
+
+	// "Sliced Multi-modulus Blind Equalization Algorithm",
+	// ETRI Journal, Volume 27, Number 3, June 2005,
+	// Shafayat Abrar and Roy A. Axford Jr.
+	void trainSmma(ComplexScalar const &sym_s_eq, RealScalar const &mag_h, ComplexScalar const &R, RealScalar mu)
+	{
+		ComplexScalar e(sym_s_eq.real()*(mag_h*R.real() - sym_s_eq.real()*sym_s_eq.real()), sym_s_eq.imag()*(mag_h*R.imag() - sym_s_eq.imag()*sym_s_eq.imag()));
+
+		mu /= (1+m_power);
+		Lms::update(e, mu);
+	}
+	
+private:
+	RealScalar m_xLast;
+	RealScalar m_power;
+};
+
+class Dfe : public Lms
+{
+public:
+	Dfe(uint32_t k=0)
+	: Lms(2*k+1)
+	, m_numFeedforward(k+1)
+	, m_numFeedBack(k)
+	{
+		
+	}
+	
+	~Dfe()
+	{
+		
+	}
+	void init(uint32_t k)
+	{
+		setNumTaps(2*k+1);
+		m_numFeedforward = k+1;
+		m_numFeedBack = k;
+	}
+
+	ComplexScalar process(ComplexScalar const &xs, ComplexScalar const &xh)
+	{
+		int32_t i;
+		CVec &x = m_x;
+		
+		// x(0:size-1) = [xs, x(0:m_numFeedforward-2), xh, x(m_numFeedforward:size-2)]
+		m_x.reverse() << m_x.segment(m_numFeedforward-1, m_numFeedBack).reverse(),xh,m_x.segment(0, m_numFeedforward-2).reverse(),xs;
+
+		return FirComplex::process(m_w);
+	}
+
+	void train(ComplexScalar e, RealScalar mu)
+	{
+		Lms::update(e, mu);
+	}
+	
+private:
+	uint32_t m_numFeedforward;
+	uint32_t m_numFeedBack;
+	
+};
+
+} // Radio::Equalizer
+} // ::Radio
+
+
+#endif	/* EQUALIZER_HPP */
+