feat(dmr): decode CACH and slot type

2026-08-25 18:43:51 +00:00 · 2026-07-14 18:46:49 +03:00
parent 3fcf737685
commit 23596d0565
5 changed files with 367 additions and 6 deletions
@@ -0,0 +1,94 @@
+program dmr_protocol_test;
+
+{$MODE Delphi}
+
+uses
+  SysUtils, DMRProtocol;
+
+const
+  CACH_INTERLEAVE: array[0..23] of Byte = (
+     0,  7,  8,  9,  1, 10,
+    11, 12,  2, 13, 14, 15,
+     3, 16,  4, 17, 18, 19,
+     5, 20, 21, 22,  6, 23
+  );
+
+procedure PutCACH(var Burst: TDMRDibitBurst; Value: Byte);
+var
+  Code: TDMRBit7;
+  Deinterleaved, Transmitted: array[0..23] of Byte;
+  i: Integer;
+begin
+  FillChar(Deinterleaved, SizeOf(Deinterleaved), 0);
+  Code := DMRHamming74Encode(Value);
+  for i := 0 to 6 do Deinterleaved[i] := Code[i];
+  for i := 0 to 23 do Transmitted[i] := Deinterleaved[CACH_INTERLEAVE[i]];
+  for i := 0 to 11 do
+    Burst[i] := (Transmitted[2 * i] shl 1) or Transmitted[2 * i + 1];
+end;
+
+procedure PutSlotType(var Burst: TDMRDibitBurst; Value: Byte);
+var
+  Code: TDMRBit20;
+  i, k: Integer;
+begin
+  Code := DMRGolay208Encode(Value);
+  k := 0;
+  for i := 61 to 65 do
+  begin
+    Burst[i] := (Code[k] shl 1) or Code[k + 1];
+    Inc(k, 2);
+  end;
+  for i := 90 to 94 do
+  begin
+    Burst[i] := (Code[k] shl 1) or Code[k + 1];
+    Inc(k, 2);
+  end;
+end;
+
+procedure Check(Condition: Boolean; const Message_: string);
+begin
+  if not Condition then
+  begin
+    WriteLn(Message_);
+    Halt(1);
+  end;
+end;
+
+var
+  Burst: TDMRDibitBurst;
+  Info: TDMRBurstInfo;
+begin
+  FillChar(Burst, SizeOf(Burst), 0);
+  // TACT: AT=1, slot=1 (TS2), LCSS=2. Slot Type: CC=9, data header=6.
+  PutCACH(Burst, $0E);
+  PutSlotType(Burst, $96);
+  DMRParseBurst(Burst, Info);
+  Check(Info.CACH.Valid, 'valid CACH rejected');
+  Check(Info.CACH.AccessType and (Info.CACH.Slot = 1) and
+        (Info.CACH.LCSS = 2), 'TACT fields decoded incorrectly');
+  Check(Info.SlotType.Valid, 'valid Slot Type rejected');
+  Check((Info.SlotType.ColorCode = 9) and (Info.SlotType.DataType = 6),
+        'Slot Type fields decoded incorrectly');
+
+  // Hamming(7,4) corrects one bit and Golay(20,8) corrects two.
+  Burst[0] := Burst[0] xor 2;
+  Burst[61] := Burst[61] xor 2;
+  Burst[92] := Burst[92] xor 1;
+  DMRParseBurst(Burst, Info);
+  Check(Info.CACH.Valid and (Info.CACH.CorrectedBits = 1),
+        'CACH one-bit correction failed');
+  Check(Info.CACH.AccessType and (Info.CACH.Slot = 1) and
+        (Info.CACH.LCSS = 2), 'corrected TACT fields are wrong');
+  Check(Info.SlotType.Valid and (Info.SlotType.CorrectedBits = 2),
+        'Slot Type two-bit correction failed');
+  Check((Info.SlotType.ColorCode = 9) and (Info.SlotType.DataType = 6),
+        'corrected Slot Type fields are wrong');
+
+  // A third Slot Type error exceeds the guaranteed correction radius.
+  Burst[94] := Burst[94] xor 1;
+  DMRParseBurst(Burst, Info);
+  Check(not Info.SlotType.Valid, 'uncorrectable Slot Type accepted');
+
+  WriteLn('DMR CACH and Slot Type tests passed');
+end.