Initial code check in continued

2026-11-12 08:37:25 -05:00 · 2014-04-26 19:48:24 +00:00
parent 960a6f9952
commit 3dfedcf8d1
474 changed files with 76613 additions and 0 deletions
--- a/src/decode/ltrstandard/LTRStandardDecoder.java
+++ b/src/decode/ltrstandard/LTRStandardDecoder.java
@@ -0,0 +1,117 @@
+/*******************************************************************************
+ *     SDR Trunk 
+ *     Copyright (C) 2014 Dennis Sheirer
+ * 
+ *     This program is free software: you can redistribute it and/or modify
+ *     it under the terms of the GNU General Public License as published by
+ *     the Free Software Foundation, either version 3 of the License, or
+ *     (at your option) any later version.
+ * 
+ *     This program is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ * 
+ *     You should have received a copy of the GNU General Public License
+ *     along with this program.  If not, see <http://www.gnu.org/licenses/>
+ ******************************************************************************/
+package decode.ltrstandard;
+
+import message.MessageDirection;
+import source.Source.SampleType;
+import alias.AliasList;
+import bits.MessageFramer;
+import bits.SyncPattern;
+import decode.Decoder;
+import decode.DecoderType;
+import dsp.filter.DCRemovalFilter2;
+import dsp.nbfm.FilteringNBFMDemodulator;
+
+public class LTRStandardDecoder extends Decoder
+{
+	/**
+	 * This value determines how quickly the DC remove filter responds to 
+	 * changes in frequency.
+	 */
+	private static final double sDC_REMOVAL_RATIO = 0.000003;
+
+	public static final int sLTR_STANDARD_MESSAGE_LENGTH = 40;
+	private FilteringNBFMDemodulator mDemodulator;
+	private DCRemovalFilter2 mDCRemovalFilter; 
+	private LTRFSKDemodulator mLTRFSKDemodulator;
+	private MessageFramer mLTRMessageFramer;
+	private LTRStandardMessageProcessor mLTRMessageProcessor;
+
+	public LTRStandardDecoder( SampleType sampleType, 
+					   AliasList aliasList,
+					   MessageDirection direction )
+	{
+		super( sampleType );
+		
+		/**
+		 * Only setup a demod chain if we're receiving complex samples.  If
+		 * we're receiving demodulated samples, they'll be handled the same 
+		 * was as we handle the output of the demodulator.
+		 */
+		if( mSourceSampleType == SampleType.COMPLEX )
+		{
+			/**
+			 * The Decoder super class is both a Complex listener and a Short
+			 * listener.  So, we add the demod to listen to the incoming 
+			 * quadrature samples, and we wire the output of the demod right
+			 * back to this class, so we can receive the demodulated output
+			 * to process
+			 */
+			mDemodulator = new FilteringNBFMDemodulator();
+			this.addComplexListener( mDemodulator );
+
+			/**
+			 * Remove the DC component that is present when we're mistuned
+			 */
+			mDCRemovalFilter = new DCRemovalFilter2( sDC_REMOVAL_RATIO );
+			mDemodulator.addListener( mDCRemovalFilter );
+			
+			mDCRemovalFilter.setListener( this.getFloatReceiver() );
+		}
+
+		mLTRFSKDemodulator = new LTRFSKDemodulator();
+
+		/**
+		 * The DC removal filter will impact performance of the LTRFSKDemod,
+		 * so we get the samples straight from the NBFM demod
+		 */
+		if( mSourceSampleType == SampleType.COMPLEX )
+		{
+			mDemodulator.addListener( mLTRFSKDemodulator );
+		}
+		else
+		{
+			mDCRemovalFilter.setListener( mLTRFSKDemodulator );
+		}
+		
+		if( direction == MessageDirection.OSW )
+		{
+			mLTRMessageFramer = 
+					new MessageFramer( SyncPattern.LTR_STANDARD_OSW.getPattern(),
+							sLTR_STANDARD_MESSAGE_LENGTH );
+		}
+		else
+		{
+			mLTRMessageFramer = 
+					new MessageFramer( SyncPattern.LTR_STANDARD_ISW.getPattern(),
+							sLTR_STANDARD_MESSAGE_LENGTH );
+		}
+		
+		mLTRFSKDemodulator.addListener( mLTRMessageFramer );
+
+		mLTRMessageProcessor = new LTRStandardMessageProcessor( direction, aliasList );
+		mLTRMessageFramer.addMessageListener( mLTRMessageProcessor );
+		mLTRMessageProcessor.addMessageListener( this );
+	}
+
+	@Override
+    public DecoderType getType()
+    {
+	    return DecoderType.LTR_STANDARD;
+    }
+}