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Changed AGC to enhanced NFM squelch

This commit is contained in:
f4exb 2015-06-20 09:28:57 +02:00
parent e66d9a417f
commit 3cdccd2cd0
7 changed files with 141 additions and 24 deletions
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116
include-gpl/dsp/agc.h
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@ -71,7 +71,121 @@ private:
Real m_fill; // refill average at this level
Real m_cutoff; // consider samples only above this level
Real m_clip; // never go below this level
MovingAverage m_moving_average; // Averaging engine. The stack length conditions the smoothness of AGC.
MovingAverage<Real> m_moving_average; // Averaging engine. The stack length conditions the smoothness of AGC.
};
class EvenSimplerAGC
{
public:
EvenSimplerAGC() :
m_u0(1.0),
m_R(1.0),
m_moving_average()
{}
EvenSimplerAGC(int historySize, Real R) :
m_u0(1.0),
m_R(R),
m_moving_average(historySize, m_R)
{}
void resize(int historySize, Real R)
{
m_R = R;
m_moving_average.resize(historySize, R);
}
Real getValue()
{
return m_u0;
}
void feed(Complex& ci)
{
ci *= m_u0;
Real magsq = ci.real()*ci.real() + ci.imag()*ci.imag();
m_moving_average.feed(magsq);
m_u0 = m_R / m_moving_average.average();
}
void close()
{
m_moving_average.fill(m_R);
m_u0 = 1.0;
}
private:
Real m_u0;
Real m_R; // objective magsq
MovingAverage<Real> m_moving_average; // Averaging engine. The stack length conditions the smoothness of AGC.
};
class AlphaAGC
{
public:
AlphaAGC() :
m_u0(1.0),
m_R(1.0),
m_alpha(0.1),
m_squelch(false),
m_moving_average()
{}
AlphaAGC(int historySize, Real R, Real alpha) :
m_u0(1.0),
m_R(R),
m_alpha(alpha),
m_squelch(false),
m_moving_average(historySize, m_R)
{}
void resize(int historySize, Real R, Real alpha)
{
m_R = R;
m_alpha = alpha;
m_squelch = false;
m_moving_average.resize(historySize, R);
}
Real getValue()
{
return m_u0;
}
void feed(Complex& ci)
{
ci *= m_u0;
Real magsq = ci.real()*ci.real() + ci.imag()*ci.imag();
if (m_squelch && (magsq < m_moving_average.average()))
{
m_moving_average.feed(m_moving_average.average() - m_alpha*(m_moving_average.average() - magsq));
}
else
{
m_squelch = true;
m_moving_average.feed(magsq);
}
m_u0 = m_R / m_moving_average.average();
}
void close()
{
m_moving_average.fill(m_R);
m_u0 = 1.0;
m_squelch = false;
}
private:
Real m_u0;
Real m_R; // objective magsq
Real m_alpha;
bool m_squelch;
MovingAverage<Real> m_moving_average; // Averaging engine. The stack length conditions the smoothness of AGC.
};

24
include-gpl/dsp/movingaverage.h
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@ -4,7 +4,7 @@
#include <vector>
#include "dsp/dsptypes.h"
class MovingAverage {
template<class Type> class MovingAverage {
public:
MovingAverage() :
m_history(),
@ -13,23 +13,23 @@ public:
{
}
MovingAverage(int historySize, Real initial) :
MovingAverage(int historySize, Type initial) :
m_history(historySize, initial),
m_sum(historySize * initial),
m_sum((float) historySize * initial),
m_ptr(0)
{
}
void resize(int historySize, Real initial)
void resize(int historySize, Type initial)
{
m_history.resize(historySize);
for(size_t i = 0; i < m_history.size(); i++)
m_history[i] = initial;
m_sum = m_history.size() * initial;
m_sum = (float) m_history.size() * initial;
m_ptr = 0;
}
void feed(Real value)
void feed(Type value)
{
m_sum -= m_history[m_ptr];
m_history[m_ptr] = value;
@ -39,21 +39,21 @@ public:
m_ptr = 0;
}
void fill(Real value)
void fill(Type value)
{
for(size_t i = 0; i < m_history.size(); i++)
m_history[i] = value;
m_sum = m_history.size() * value;
m_sum = (float) m_history.size() * value;
}
Real average() const
Type average() const
{
return m_sum / (Real)m_history.size();
return m_sum / (float) m_history.size();
}
protected:
std::vector<Real> m_history;
Real m_sum;
std::vector<Type> m_history;
Type m_sum;
uint m_ptr;
};

2
plugins/channel/am/amdemod.h
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@ -117,7 +117,7 @@ private:
Real m_lastArgument;
Complex m_lastSample;
MovingAverage m_movingAverage;
MovingAverage<Real> m_movingAverage;
SimpleAGC m_volumeAGC;
AudioVector m_audioBuffer;

13
plugins/channel/nfm/nfmdemod.cpp
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@ -26,7 +26,7 @@
#include <iostream>
static const Real afSqTones[2] = {2000.0, 8000.0};
static const Real afSqTones[2] = {1200.0, 8000.0};
MESSAGE_CLASS_DEFINITION(NFMDemod::MsgConfigureNFMDemod, Message)
@ -53,10 +53,11 @@ NFMDemod::NFMDemod(AudioFifo* audioFifo, SampleSink* sampleSink) :
m_movingAverage.resize(16, 0);
m_agcLevel = 0.003;
m_AGC.resize(4096, m_agcLevel, 0, 0.1*m_agcLevel);
//m_AGC.resize(480, m_agcLevel, 0, 0.1*m_agcLevel);
m_AGC.resize(240, m_agcLevel*m_agcLevel, 0.1);
m_ctcssDetector.setCoefficients(3000, 6000.0); // 0.5s / 2 Hz resolution
m_afSquelch.setCoefficients(24, 48000.0, 1, 1); // 4000 Hz span, 250us
m_afSquelch.setCoefficients(24, 48000.0, 5, 1); // 4000 Hz span, 250us
m_afSquelch.setThreshold(0.001);
}
@ -117,8 +118,10 @@ void NFMDemod::feed(SampleVector::const_iterator begin, SampleVector::const_iter
qint16 sample;
m_AGC.feed(abs(ci));
ci *= (m_agcLevel / m_AGC.getValue());
//m_AGC.feed(abs(ci));
//ci *= (m_agcLevel / m_AGC.getValue());
m_AGC.feed(ci);
// demod
/*

4
plugins/channel/nfm/nfmdemod.h
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@ -145,8 +145,8 @@ private:
Real m_lastArgument;
Complex m_m1Sample;
Complex m_m2Sample;
MovingAverage m_movingAverage;
SimpleAGC m_AGC;
MovingAverage<Real> m_movingAverage;
AlphaAGC m_AGC;
Real m_agcLevel; // AGC will aim to this level
Real m_agcFloor; // AGC will not go below this level

2
plugins/channel/wfm/wfmdemod.h
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@ -122,7 +122,7 @@ private:
Real m_lastArgument;
Complex m_m1Sample; // x^-1 sample
Complex m_m2Sample; // x^-1 sample
MovingAverage m_movingAverage;
MovingAverage<Real> m_movingAverage;
AudioVector m_audioBuffer;
uint m_audioBufferFill;

4
sdrbase/dsp/afsquelch.cpp
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@ -189,7 +189,7 @@ void AFSquelch::evaluate()
if (open)
{
if (attackCount < samplesAttack)
if (samplesAttack && (attackCount < samplesAttack))
{
attackCount++;
}
@ -201,7 +201,7 @@ void AFSquelch::evaluate()
}
else
{
if (decayCount < samplesDecay)
if (samplesDecay && (decayCount < samplesDecay))
{
decayCount++;
}