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#6 DMR Decoder (#947)

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* #6 DMR decoder feature - work in progress

* #6 DMR Decoder.

* #6 DMR Decoder.  Code review updates.

Co-authored-by: Zhenyu Mao <maozhenyu@foxmail.com>
Co-authored-by: Denny <denny@denny-desktop>
This commit is contained in:
Denny Sheirer
2020-10-12 04:57:59 -04:00
committed by GitHub
parent b061db1189
commit 7eec82deee
436 changed files with 36258 additions and 2409 deletions
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6
src/main/java/io/github/dsheirer/edac/trellis/DMR_3_4_Node.java
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@@ -83,4 +83,10 @@ public class DMR_3_4_Node extends Node
{
return DMR_TRANSITION_MATRIX[precedingNode.getInputValue()][getInputValue()];
}
@Override
public String toString()
{
return "IN:" + getInputValue() + " OUT:" + getTransmittedOutputValue();
}
}

8
src/main/java/io/github/dsheirer/edac/trellis/Path.java
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@@ -18,6 +18,8 @@
******************************************************************************/
package io.github.dsheirer.edac.trellis;
import com.google.common.base.Joiner;
import java.util.ArrayList;
import java.util.List;
@@ -128,4 +130,10 @@ public class Path
{
return new Path(this);
}
@Override
public String toString()
{
return "ERR:" + getError() + " " + Joiner.on(",").join(mNodes);
}
}

70
src/main/java/io/github/dsheirer/edac/trellis/ViterbiDecoder_3_4_DMR.java
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@@ -18,21 +18,77 @@
******************************************************************************/
package io.github.dsheirer.edac.trellis;
import com.google.common.base.Joiner;
import io.github.dsheirer.bits.BinaryMessage;
import io.github.dsheirer.bits.CorrectedBinaryMessage;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* Viterbi decoder for 3/4 rate trellis coded modulation (TCM) data blocks
*/
public class ViterbiDecoder_3_4_DMR extends ViterbiDecoder
{
private static final int[] DEINTERLEAVE_DIBITS = new int[]{0, 1, 8, 9, 16, 17, 24, 25, 32, 33, 40, 41, 48, 49, 56, 57, 64, 65, 72, 73, 80, 81,
88, 89, 96, 97, 2, 3, 10, 11, 18, 19, 26, 27, 34, 35, 42, 43, 50, 51, 58, 59, 66, 67, 74, 75, 82, 83, 90, 91, 4, 5, 12, 13, 20, 21, 28, 29, 36, 37, 44, 45,
52, 53, 60, 61, 68, 69, 76, 77, 84, 85, 92, 93, 6, 7, 14, 15, 22, 23, 30, 31, 38, 39, 46, 47, 54, 55, 62, 63, 70, 71, 78, 79, 86, 87, 94, 95};
private static final int[] DEINTERLEAVE_INDEXES = new int[]{0, 1, 2, 3, 16, 17, 18, 19, 32, 33, 34, 35, 48, 49, 50,
51, 64, 65, 66, 67, 80, 81, 82, 83, 96, 97, 98, 99, 112, 113, 114, 115, 128, 129, 130, 131, 144, 145, 146, 147,
160, 161, 162, 163, 176, 177, 178, 179, 192, 193, 194, 195, 4, 5, 6, 7, 20, 21, 22, 23, 36, 37, 38, 39, 52, 53,
54, 55, 68, 69, 70, 71, 84, 85, 86, 87, 100, 101, 102, 103, 116, 117, 118, 119, 132, 133, 134, 135, 148, 149,
150, 151, 164, 165, 166, 167, 180, 181, 182, 183, 8, 9, 10, 11, 24, 25, 26, 27, 40, 41, 42, 43, 56, 57, 58, 59,
72, 73, 74, 75, 88, 89, 90, 91, 104, 105, 106, 107, 120, 121, 122, 123, 136, 137, 138, 139, 152, 153, 154, 155,
168, 169, 170, 171, 184, 185, 186, 187, 12, 13, 14, 15, 28, 29, 30, 31, 44, 45, 46, 47, 60, 61, 62, 63, 76, 77,
78, 79, 92, 93, 94, 95, 108, 109, 110, 111, 124, 125, 126, 127, 140, 141, 142, 143, 156, 157, 158, 159, 172,
173, 174, 175, 188, 189, 190, 191};
/**
* Viterbi decoder for Digital Mobile Radio (DMR) 3/4 rate Trellis Coded Modulation (TCM) encoded messages.
*/
public ViterbiDecoder_3_4_DMR()
{
super(3,4);
super(3, 4);
}
public static void main(String[] args)
{
List<Integer> indexes = new ArrayList<>();
for(int i : DEINTERLEAVE_DIBITS)
{
indexes.add(i * 2);
indexes.add(i * 2 + 1);
}
System.out.println(Joiner.on(",").join(indexes));
Collections.sort(indexes);
System.out.println(Joiner.on(",").join(indexes));
}
/**
* Performs deinterleave of transmitted 3/4 TCM encoded payload
* @param interleaved
* @return
*/
private static CorrectedBinaryMessage deinterleave(CorrectedBinaryMessage interleaved)
{
CorrectedBinaryMessage deinterleaved = new CorrectedBinaryMessage(196);
for(int x = 0; x < 196; x++)
{
if(interleaved.get(x))
{
deinterleaved.set(DEINTERLEAVE_INDEXES[x]);
}
}
return deinterleaved;
}
/**
* Decodes a 3/4 rate trellis coded modulation (TCM) encoded DMR binary message containing 196 bits that have
* already been deinterleaved.
@@ -40,12 +96,11 @@ public class ViterbiDecoder_3_4_DMR extends ViterbiDecoder
* @param encodedMessage to decode that has already been deinterleaved.
* @return decoded message
*/
public CorrectedBinaryMessage decode(BinaryMessage encodedMessage)
public CorrectedBinaryMessage decode(CorrectedBinaryMessage encodedMessage)
{
int[] symbols = getSymbols(encodedMessage);
CorrectedBinaryMessage deinterleaved = deinterleave(encodedMessage);
int[] symbols = getSymbols(deinterleaved);
Path mostLikelyPath = decode(symbols);
return getMessage(mostLikelyPath);
}
@@ -104,7 +159,7 @@ public class ViterbiDecoder_3_4_DMR extends ViterbiDecoder
//Ensure we have an integral number of transmitted symbols (nibbles) in the message
if(encodedMessage.size() % getOutputBitLength() != 0)
{
throw new IllegalArgumentException("Encoded message must contain an integral number of 4-bit symbols -" +
throw new IllegalArgumentException("Encoded message must contain an integral number of 4-bit symbols -" +
" message size: " + encodedMessage.size());
}
@@ -125,6 +180,7 @@ public class ViterbiDecoder_3_4_DMR extends ViterbiDecoder
/**
* Creates a DMR node
*
* @param inputValue for the specific trellis node
* @param transmittedOutputValue the actual transmitted output value
* @return created node
@@ -154,6 +210,6 @@ public class ViterbiDecoder_3_4_DMR extends ViterbiDecoder
@Override
protected Node createStartingNode()
{
return new DMR_3_4_Node(0,0);
return new DMR_3_4_Node(0, 0);
}
}