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P25 - updated automatic and direct frequency control to cleanup the code and allow P25 to better track frequency and PPM changes in the tuner and provide a cleaner implementation of the AFC component in the processing chain of all of the other decoders.

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Changed C4FM symbol filter to reset frequency tracking values when the tuner's frequency or PPM values change.

Moved all frequency control pieces into the source.tuner.frequency package.
This commit is contained in:
dennis.sheirer
2015-05-04 00:55:04 +00:00
parent d2020cdba0
commit bc5080aa4a
44 changed files with 533 additions and 337 deletions
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204
src/dsp/frequency/AutomaticFrequencyControl.java
View File

@@ -1,204 +0,0 @@
package dsp.frequency;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import sample.real.RealSampleListener;
import source.tuner.FrequencyChangeEvent;
import source.tuner.FrequencyChangeEvent.Attribute;
import source.tuner.FrequencyChangeListener;
import buffer.FloatAveragingBuffer;
public class AutomaticFrequencyControl implements RealSampleListener,
FrequencyChangeListener
{
private final static Logger mLog =
LoggerFactory.getLogger( AutomaticFrequencyControl.class );
private static float LARGE_ERROR = 0.300f;
private static float MEDIUM_ERROR = 0.150f;
private static float SMALL_ERROR = 0.030f;
private static float FINE_ERROR = 0.015f;
private static int LARGE_FREQUENCY_CORRECTION = 1500; //Hertz
private static int MEDIUM_FREQUENCY_CORRECTION = 500;
private static int SMALL_FREQUENCY_CORRECTION = 100;
private static int FINE_FREQUENCY_CORRECTION = 50;
private static int SAMPLE_THRESHOLD = 15000;
private Mode mMode = Mode.FAST;
private FloatAveragingBuffer mBuffer =
new FloatAveragingBuffer( SAMPLE_THRESHOLD );
private int mSampleCounter = 0;
private int mSkipCounter = 0;
private int mSkipThreshold = 4;
private int mErrorCorrection = 0;
private long mCurrentFrequency;
private int mMaximumCorrection;
private FrequencyChangeListener mListener;
public enum Mode
{
NORMAL,FAST;
}
public AutomaticFrequencyControl( FrequencyChangeListener listener,
int maximumCorrection )
{
mListener = listener;
mMaximumCorrection = maximumCorrection;
}
public void dispose()
{
mListener = null;
mBuffer = null;
}
public int getErrorCorrection()
{
return mErrorCorrection;
}
public void reset()
{
mErrorCorrection = 0;
mMode = Mode.FAST;
dispatch();
}
private void dispatch()
{
if( mListener != null )
{
mListener.frequencyChanged(
new FrequencyChangeEvent( Attribute.FREQUENCY_ERROR,
mErrorCorrection ) );
}
}
@Override
public void receive( float sample )
{
if( mMode == Mode.FAST )
{
float average = mBuffer.get( sample );
mSampleCounter++;
if( mSampleCounter >= SAMPLE_THRESHOLD )
{
mSampleCounter = 0;
update( average );
}
}
else
{
mSkipCounter++;
if( mSkipCounter >= mSkipThreshold )
{
mSkipCounter = 0;
float average = mBuffer.get( sample );
mSampleCounter++;
if( mSampleCounter >= SAMPLE_THRESHOLD )
{
mSampleCounter = 0;
update( average );
}
}
}
}
private void update( float average )
{
int correction = 0;
if( average > LARGE_ERROR )
{
correction = -LARGE_FREQUENCY_CORRECTION;
mMode = Mode.FAST;
}
else if( average > MEDIUM_ERROR )
{
correction = -MEDIUM_FREQUENCY_CORRECTION;
mMode = Mode.FAST;
}
else if( average > SMALL_ERROR )
{
correction = -SMALL_FREQUENCY_CORRECTION;
mMode = Mode.NORMAL;
}
else if( average > FINE_ERROR )
{
correction = -FINE_FREQUENCY_CORRECTION;
mMode = Mode.NORMAL;
}
else if( average < -LARGE_ERROR )
{
correction = LARGE_FREQUENCY_CORRECTION;
mMode = Mode.FAST;
}
else if( average < -MEDIUM_ERROR )
{
correction = MEDIUM_FREQUENCY_CORRECTION;
mMode = Mode.FAST;
}
else if( average < -SMALL_ERROR )
{
correction = SMALL_FREQUENCY_CORRECTION;
mMode = Mode.NORMAL;
}
else if( average < -FINE_ERROR )
{
correction = FINE_FREQUENCY_CORRECTION;
mMode = Mode.NORMAL;
}
if( correction != 0 )
{
mErrorCorrection -= correction;
if( Math.abs( mErrorCorrection ) > mMaximumCorrection )
{
mErrorCorrection = ( mErrorCorrection < 0 ) ?
-mMaximumCorrection :
mMaximumCorrection;
}
dispatch();
}
else
{
mMode = Mode.NORMAL;
}
}
@Override
public void frequencyChanged( FrequencyChangeEvent event )
{
switch( event.getAttribute() )
{
case FREQUENCY:
int frequency = (int)event.getValue();
if( mCurrentFrequency != frequency )
{
mCurrentFrequency = frequency;
reset();
}
case SAMPLE_RATE_ERROR:
break;
default:
break;
}
}
}

17
src/dsp/psk/CQPSKDemodulator.java
View File

@@ -36,6 +36,7 @@ import instrument.tap.stream.EyeDiagramDataTap;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.slf4j.Logger;
@@ -44,7 +45,7 @@ import org.slf4j.LoggerFactory;
import sample.Listener;
import sample.Provider;
import sample.complex.ComplexSample;
import source.tuner.FrequencyChangeListener;
import source.tuner.frequency.FrequencyChangeListener;
import buffer.FloatAveragingBuffer;
import dsp.filter.interpolator.QPSKInterpolator;
@@ -297,13 +298,13 @@ public class CQPSKDemodulator implements Instrumentable,
middleSymbol.normalize();
currentSymbol.normalize();
// if( mEyeDiagramDataTap != null )
// {
// mEyeDiagramDataTap.receive(
// new EyeDiagramData( Arrays.copyOfRange( mDelayLine,
// mDelayLinePointer, mDelayLinePointer + 20 ),
// mMu, (float)half_sps + half_mu ) );
// }
if( mEyeDiagramDataTap != null )
{
mEyeDiagramDataTap.receive(
new EyeDiagramData( Arrays.copyOfRange( mDelayLine,
mDelayLinePointer, mDelayLinePointer + 20 ),
mMu, (float)half_sps + half_mu ) );
}
/* Gardner timing error calculations */
float errorInphase = ( mPreviousSymbol.inphase() -