P25 - added parsing of packet payload data for confirmed PDUs.

src/gui/control/ConstellationViewer.java

@@ -0,0 +1,198 @@
+package gui.control;
+
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.event.MouseEvent;
+import java.awt.event.MouseListener;
+import java.awt.geom.Ellipse2D;
+import java.util.List;
+
+import javax.swing.JPanel;
+import javax.swing.JPopupMenu;
+import javax.swing.JSlider;
+import javax.swing.SwingUtilities;
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ChangeListener;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import sample.Listener;
+import sample.complex.ComplexSample;
+import buffer.CircularBuffer;
+
+public class ConstellationViewer extends JPanel 
+								 implements Listener<ComplexSample>
+{
+	private static final long serialVersionUID = 1L;
+	
+	private final static Logger mLog = 
+						LoggerFactory.getLogger( ConstellationViewer.class );
+
+	private int mSampleRate;
+	private int mSymbolRate;
+	private float mSamplesPerSymbol;
+	private float mCounter = 0;
+	private float mOffset = 0;
+	private CircularBuffer<ComplexSample> mBuffer =
+						new CircularBuffer<ComplexSample>( 5000 );
+	private ComplexSample mPrevious = new ComplexSample( 1, 1 );
+	
+	public ConstellationViewer( int sampleRate, int symbolRate )
+	{
+		mSampleRate = sampleRate;
+		mSymbolRate = symbolRate;
+		mSamplesPerSymbol = (float)mSampleRate / (float)mSymbolRate;
+		
+		initGui();
+	}
+	
+	private void initGui()
+	{
+		setPreferredSize( new Dimension( 200,200 ) );
+		
+		addMouseListener( new MouseListener()
+		{
+			@Override
+			public void mouseClicked( MouseEvent e )
+			{
+				if( SwingUtilities.isRightMouseButton( e ) )
+				{
+					JPopupMenu menu = new JPopupMenu();
+					
+					menu.add( new TimingOffsetItem( (int)( mSamplesPerSymbol * 10 ), (int)( mOffset * 10 ) ) );
+					
+					menu.show( ConstellationViewer.this, e.getX(), e.getY() );
+				}
+			}
+			
+			public void mouseReleased( MouseEvent e ) {}
+			public void mousePressed( MouseEvent e ) {}
+			public void mouseExited( MouseEvent e ) {}
+			public void mouseEntered( MouseEvent e ) {}
+		} );
+	}
+
+	@Override
+	public void receive( ComplexSample sample )
+	{
+		mBuffer.receive( sample );
+		
+		repaint();
+	}
+	
+	/**
+	 * Sets the timing offset ( 0 <> SamplesPerSymbol ) for selecting which
+	 * sample to plot, within the symbol timeframe.  Values greater than the
+	 * samples per symbol value will simply wrap or delay into the next symbol
+	 * period.
+	 * 
+	 * @param offset
+	 */
+	public void setOffset( float offset )
+	{
+		mOffset = offset;
+		
+		repaint();
+	}
+
+    @Override
+    public void paintComponent( Graphics g )
+    {
+    	super.paintComponent( g );
+    	
+    	Graphics2D graphics = (Graphics2D) g;
+    	
+//    	graphics.setBackground( Color.BLACK );
+    	graphics.setColor( Color.BLUE );
+
+    	List<ComplexSample> samples = mBuffer.getElements();
+    	
+    	double centerX = (double)getHeight() / 2.0d;
+    	double centerY = (double)getWidth() / 2.0d;
+    	
+//    	double scale = centerX / 2.0d;
+    	
+    	double scale = 0.5d;
+    	
+    	mCounter = 0;
+    	
+    	for( ComplexSample sample: samples )
+    	{
+    		
+    		if( mCounter > ( mOffset + mSamplesPerSymbol ) )
+    		{
+        		/**
+        		 * Multiply the current sample against the complex conjugate of the 
+        		 * previous sample to derive the phase delta between the two samples
+        		 * 
+        		 * Negating the previous sample quadrature produces the conjugate
+        		 */
+        		double i = ( sample.inphase() * mPrevious.inphase() ) - 
+        				( sample.quadrature() * -mPrevious.quadrature() );
+        		double q = ( sample.quadrature() * mPrevious.inphase() ) + 
+        				( sample.inphase() * -mPrevious.quadrature() );
+
+        		mLog.debug( "i:" + i + " q:" + q );
+        		double angle;
+
+        		//Check for divide by zero
+        		if( i == 0 )
+        		{
+        			angle = 0.0;
+        		}
+        		else
+        		{
+        			/**
+        			 * Use the arcus tangent of imaginary (q) divided by real (i) to
+        			 * get the phase angle (+/-) which was directly manipulated by the
+        			 * original message waveform during the modulation.  This value now
+        			 * serves as the instantaneous amplitude of the demodulated signal
+        			 */
+        			double denominator = 1.0d / i;
+        			angle = Math.atan( (double)q * denominator );
+        		}
+        		
+        		Ellipse2D.Double ellipse = 
+        				new Ellipse2D.Double( centerX - ( i * scale ), 
+        						centerY - ( q * scale ), 4, 4 );
+        		
+        		graphics.draw( ellipse );
+        		
+        		mCounter -= mSamplesPerSymbol;
+    		}
+
+    		mCounter++;
+    		
+//    		mLog.debug( "Plotting x:" + ( centerX - ( sample.x() * scale ) ) + 
+//    				    " y:" + ( centerY - ( sample.y() * scale ) ) + " for sample " + sample.toString() );
+    	}
+    }
+    
+    public class TimingOffsetItem extends JSlider implements ChangeListener
+    {
+        private static final long serialVersionUID = 1L;
+
+        public TimingOffsetItem( int maxValue, int currentValue )
+        {
+        	super( JSlider.HORIZONTAL, 0, maxValue, currentValue );
+
+        	setMajorTickSpacing( 10 );
+        	setMinorTickSpacing( 5 );
+        	setPaintTicks( true );
+        	setPaintLabels( true );
+        	
+        	addChangeListener( this );
+        }
+
+    	@Override
+        public void stateChanged( ChangeEvent event )
+        {
+    		int value = ((JSlider)event.getSource()).getValue();
+    		
+    		setOffset( (float)value / 10.0f );
+        }
+    }
+}