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Tuner Channel - uses new CIC prime decimation filter for decimating channel to 48k sample rate.

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dennis.sheirer
2015-04-07 01:10:10 +00:00
parent 90149fe600
commit d55d7609cb
6 changed files with 112 additions and 209 deletions
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81
src/source/tuner/TunerChannelSource.java
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@@ -37,8 +37,7 @@ import source.tuner.FrequencyChangeEvent.Attribute;
import util.Oscillator;
import controller.ThreadPoolManager;
import controller.ThreadPoolManager.ThreadType;
import decode.p25.P25Decoder;
import dsp.filter.ComplexFilter;
import dsp.filter.ComplexPrimeCICDecimate;
import dsp.filter.FilterFactory;
import dsp.filter.Window.WindowType;
@@ -49,15 +48,15 @@ public class TunerChannelSource extends ComplexSource
private final static Logger mLog =
LoggerFactory.getLogger( TunerChannelSource.class );
private static int sCHANNEL_RATE = 48000;
private static int sCHANNEL_PASS_FREQUENCY = 12500;
private static int CHANNEL_RATE = 48000;
private static int CHANNEL_PASS_FREQUENCY = 12000;
private LinkedTransferQueue<ComplexBuffer> mBuffer =
new LinkedTransferQueue<ComplexBuffer>();
private Tuner mTuner;
private TunerChannel mTunerChannel;
private Oscillator mSineWaveGenerator;
private ComplexFilter[] mDecimationFilters;
private ComplexPrimeCICDecimate mDecimationFilter;
private ComplexSampleAssembler mBufferAssembler =
new ComplexSampleAssembler( 3000 );
@@ -71,7 +70,7 @@ public class TunerChannelSource extends ComplexSource
public TunerChannelSource( ThreadPoolManager threadPoolManager,
Tuner tuner,
TunerChannel tunerChannel )
throws RejectedExecutionException, SourceException
throws RejectedExecutionException, SourceException
{
super( "Tuner Channel Source" );
@@ -118,11 +117,8 @@ public class TunerChannelSource extends ComplexSource
mBuffer.clear();
mBuffer = null;
for( ComplexFilter filter: mDecimationFilters )
{
filter.dispose();
}
mDecimationFilter.dispose();
mBufferAssembler.dispose();
@@ -160,8 +156,6 @@ public class TunerChannelSource extends ComplexSource
public void removeListener( Listener<List<ComplexSample>> listener )
{
mBufferAssembler.removeListener( listener );
mDecimationFilters[ mDecimationFilters.length - 1 ]
.setListener( null );
}
@Override
@@ -184,28 +178,18 @@ public class TunerChannelSource extends ComplexSource
{
/* Set the oscillator to the new frequency */
mSineWaveGenerator.setSampleRate( sampleRate );
/* Get new decimation filters */
mDecimationFilters = FilterFactory
.getDecimationFilters( sampleRate,
sCHANNEL_RATE,
sCHANNEL_PASS_FREQUENCY,
48, //dB attenuation
WindowType.HAMMING );
/* wire the filters together */
if( mDecimationFilters.length > 1 )
{
for( int x = 1; x < mDecimationFilters.length; x++ )
{
mDecimationFilters[ x - 1 ]
.setListener( mDecimationFilters[ x ] );
}
}
/* Get new decimation filter */
mDecimationFilter = FilterFactory
.getDecimationFilter( sampleRate,
CHANNEL_RATE,
2, //Order
CHANNEL_PASS_FREQUENCY,
60, //dB attenuation
WindowType.HAMMING );
/* re-add the original output listener */
mDecimationFilters[ mDecimationFilters.length - 1 ]
.setListener( mBufferAssembler );
mDecimationFilter.setListener( mBufferAssembler );
mTunerSampleRate = sampleRate;
}
@@ -265,28 +249,25 @@ public class TunerChannelSource extends ComplexSource
* and process them, causing delays and buffer refill */
mBuffer.drainTo( sampleBuffers, 4 );
for( ComplexBuffer sampleArray: sampleBuffers )
for( ComplexBuffer buffer: sampleBuffers )
{
float[] samples = sampleArray.getSamples();
float[] samples = buffer.getSamples();
float[] translated = new float[ samples.length ];
/* Perform frequency translation */
for( int x = 0; x < samples.length; x += 2 )
{
Float left = samples[ x ];
Float right = samples[ x + 1 ];
ComplexSample multiplier =
mSineWaveGenerator.nextComplex();
if( left != null && right != null )
{
/* perform frequency translation */
ComplexSample translated = ComplexSample.multiply(
mSineWaveGenerator.nextComplex(), left, right );
/* decimate the sample rate */
if( mDecimationFilters[ 0 ] != null )
{
mDecimationFilters[ 0 ].receive( translated );
}
}
translated[ x ] = ( samples[ x ] * multiplier.inphase() ) -
( samples[ x + 1 ] * multiplier.quadrature() );
translated[ x + 1 ] = ( samples[ x + 1 ] * multiplier.inphase() ) +
( samples[ x ] * multiplier.quadrature() );
}
mDecimationFilter.receive( translated );
}
sampleBuffers.clear();