VE7UWU
/
sdrangel
mirror of https://github.com/f4exb/sdrangel.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Fixed NFM strong signals handling

This commit is contained in:
f4exb 2015-09-07 01:15:55 +02:00
parent ed0d613f10
commit b31e62e73c
4 changed files with 74 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

80
include-gpl/dsp/agc.h
View File

@ -87,19 +87,25 @@ public:
EvenSimplerAGC() :
m_u0(1.0),
m_R(1.0),
m_moving_average()
m_moving_average(),
m_historySize(0),
m_count(0)
{}
EvenSimplerAGC(int historySize, Real R) :
m_u0(1.0),
m_R(R),
m_moving_average(historySize, m_R)
m_moving_average(historySize, m_R),
m_historySize(historySize),
m_count(0)
{}
void resize(int historySize, Real R)
{
m_R = R;
m_moving_average.resize(historySize, R);
m_historySize = historySize;
m_count = 0;
}
Real getValue()
@ -107,28 +113,49 @@ public:
return m_u0;
}
Real getDelayedValue()
{
if (m_count < m_historySize*m_mult)
{
return 0;
}
else
{
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);
Real mag = sqrt(ci.real()*ci.real() + ci.imag()*ci.imag());
m_moving_average.feed(mag);
}
void openedSquelch()
{
if (m_count < m_historySize*m_mult)
{
m_count++;
}
m_u0 = m_R / m_moving_average.average();
}
void closedSquelch()
{
//m_moving_average.fill(m_R); // Valgrind optim
m_u0 = 1.0;
m_count = 0;
m_u0 = m_R / m_moving_average.average();
}
private:
Real m_u0;
Real m_R; // objective magsq
Real m_R; // objective mag
MovingAverage<Real> m_moving_average; // Averaging engine. The stack length conditions the smoothness of AGC.
int m_historySize;
int m_count;
static const int m_mult = 4;
};
class AlphaAGC
@ -140,7 +167,9 @@ public:
m_R(1.0),
m_alpha(0.1),
m_squelchOpen(true),
m_moving_average()
m_moving_average(),
m_historySize(0),
m_count(0)
{}
AlphaAGC(int historySize, Real R, Real alpha) :
@ -148,7 +177,9 @@ public:
m_R(R),
m_alpha(alpha),
m_squelchOpen(true),
m_moving_average(historySize, m_R)
m_moving_average(historySize, m_R),
m_historySize(historySize),
m_count(0)
{}
void resize(int historySize, Real R, Real alpha)
@ -157,6 +188,8 @@ public:
m_alpha = alpha;
m_squelchOpen = true;
m_moving_average.resize(historySize, R);
m_historySize = historySize;
m_count = 0;
}
Real getValue()
@ -164,25 +197,42 @@ public:
return m_u0;
}
Real getDelayedValue()
{
if (m_count < m_historySize)
{
return 0;
}
else
{
return m_u0;
}
}
void feed(Complex& ci)
{
ci *= m_u0;
Real magsq = ci.real()*ci.real() + ci.imag()*ci.imag();
Real mag = sqrt(ci.real()*ci.real() + ci.imag()*ci.imag());
if (m_squelchOpen && (magsq < m_moving_average.average()))
if (m_squelchOpen && (mag < m_moving_average.average()))
{
m_moving_average.feed(m_moving_average.average() - m_alpha*(m_moving_average.average() - magsq));
m_moving_average.feed(m_moving_average.average() - m_alpha*(m_moving_average.average() - mag));
}
else
{
//m_squelchOpen = true;
m_moving_average.feed(magsq);
m_moving_average.feed(mag);
}
}
void openedSquelch()
{
if (m_count < m_historySize)
{
m_count++;
}
m_u0 = m_R / m_moving_average.average();
m_squelchOpen = true;
}
@ -190,7 +240,9 @@ public:
void closedSquelch()
{
//m_moving_average.fill(m_R); // Valgrind optim
m_u0 = 1.0;
m_count = 0;
//m_u0 = 1.0;
m_u0 = m_R / m_moving_average.average();
m_squelchOpen = false;
}
@ -200,6 +252,8 @@ private:
Real m_alpha;
bool m_squelchOpen;
MovingAverage<Real> m_moving_average; // Averaging engine. The stack length conditions the smoothness of AGC.
int m_historySize;
int m_count;
};

8
plugins/channel/nfm/nfmdemod.cpp
View File

@ -55,9 +55,9 @@ NFMDemod::NFMDemod() :
m_audioBufferFill = 0;
m_movingAverage.resize(16, 0);
m_agcLevel = 0.003; // 0.003
m_agcLevel = 0.25; // 0.003
//m_AGC.resize(480, m_agcLevel, 0, 0.1*m_agcLevel);
m_AGC.resize(240, m_agcLevel*m_agcLevel, 0.3);
m_AGC.resize(600, m_agcLevel*m_agcLevel); //, 0.3);
m_ctcssDetector.setCoefficients(3000, 6000.0); // 0.5s / 2 Hz resolution
m_afSquelch.setCoefficients(24, 48000.0, 5, 1); // 4000 Hz span, 250us
@ -165,7 +165,7 @@ void NFMDemod::feed(const SampleVector::const_iterator& begin, const SampleVecto
Real qp = ci.imag() - m_m2Sample.imag();
Real h1 = m_m1Sample.real() * qp;
Real h2 = m_m1Sample.imag() * ip;
Real demod = (h1 - h2) * 10000;
Real demod = (h1 - h2) * 30; // 10000
m_m2Sample = m_m1Sample;
m_m1Sample = ci;
@ -218,7 +218,7 @@ void NFMDemod::feed(const SampleVector::const_iterator& begin, const SampleVecto
{
demod = m_bandpass.filter(demod);
demod *= m_running.m_volume;
sample = demod * ((1<<15)/301); // denominator = bandpass filter number of taps
sample = demod * ((1<<15)/301) * m_AGC.getDelayedValue(); // denominator = bandpass filter number of taps
}
m_AGC.openedSquelch();

2
plugins/channel/nfm/nfmdemod.h
View File

@ -163,7 +163,7 @@ private:
Complex m_m1Sample;
Complex m_m2Sample;
MovingAverage<Real> m_movingAverage;
AlphaAGC m_AGC;
EvenSimplerAGC m_AGC;
Real m_agcLevel; // AGC will aim to this level
Real m_agcFloor; // AGC will not go below this level

2
sdrbase/dsp/channelizer.cpp
View File

@ -86,6 +86,8 @@ bool Channelizer::handleMessage(const Message& cmd)
{
qDebug() << "Channelizer::handleMessage: " << cmd.getIdentifier();
// TODO: apply changes only if input sample rate or requested output sample rate change. Change of center frequency has no impact.
if (DSPSignalNotification::match(cmd))
{
DSPSignalNotification& notif = (DSPSignalNotification&) cmd;