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feat(dmr): decode full link control

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This commit is contained in:
ew8bak
2026-07-14 18:51:19 +03:00
parent 23596d0565
commit e0e74b5337
4 changed files with 424 additions and 7 deletions
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tests/dmr_protocol_test.pas
+66 -1
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@@ -55,9 +55,28 @@ begin
end;
end;
procedure PutUInt(var Bits: TDMRBit96; Start, Count: Integer; Value: LongWord);
var
i: Integer;
begin
for i := 0 to Count - 1 do
Bits[Start + i] := (Value shr (Count - 1 - i)) and 1;
end;
procedure XorPayloadByte(var Bits: TDMRBit96; ByteIndex: Integer; Value: Byte);
var
i: Integer;
begin
for i := 0 to 7 do
Bits[ByteIndex * 8 + i] := Bits[ByteIndex * 8 + i] xor
((Value shr (7 - i)) and 1);
end;
var
Burst: TDMRDibitBurst;
Info: TDMRBurstInfo;
Payload: TDMRBit96;
i: Integer;
begin
FillChar(Burst, SizeOf(Burst), 0);
// TACT: AT=1, slot=1 (TS2), LCSS=2. Slot Type: CC=9, data header=6.
@@ -90,5 +109,51 @@ begin
DMRParseBurst(Burst, Info);
Check(not Info.SlotType.Valid, 'uncorrectable Slot Type accepted');
WriteLn('DMR CACH and Slot Type tests passed');
// Full Link Control is carried in a BPTC(196,96) voice LC header.
FillChar(Payload, SizeOf(Payload), 0);
PutUInt(Payload, 2, 6, 0); // group voice channel user LC
PutUInt(Payload, 8, 8, 0); // standard feature set
PutUInt(Payload, 16, 8, $21); // service options
PutUInt(Payload, 24, 24, 12345); // target/talkgroup
PutUInt(Payload, 48, 24, 678901);// source radio
DMRFullLCSetParity(Payload, 1);
DMRBPTC19696Encode(Payload, Burst);
PutCACH(Burst, $04); // TS2, LCSS=0
PutSlotType(Burst, $91); // CC9, voice LC header
DMRParseBurst(Burst, Info);
Check(Info.BPTCValid, 'valid BPTC(196,96) rejected');
for i := 0 to High(Payload) do
Check(Info.Payload96[i] = Payload[i], 'BPTC payload mismatch at bit ' +
IntToStr(i));
Check(Info.LinkControl.Decoded and (Info.LinkControl.Opcode = 0) and
(Info.LinkControl.FeatureSetID = 0) and
(Info.LinkControl.ServiceOptions = $21) and
(Info.LinkControl.TargetID = 12345) and
(Info.LinkControl.SourceID = 678901), 'Full LC fields decoded incorrectly');
// Product-code row/column correction recovers an isolated air-interface bit.
Burst[20] := Burst[20] xor 2;
DMRParseBurst(Burst, Info);
Check(Info.BPTCValid and Info.LinkControl.Decoded and
(Info.LinkControl.TargetID = 12345) and
(Info.LinkControl.SourceID = 678901), 'BPTC one-bit correction failed');
// The outer RS(12,9) code repairs one damaged byte after clean BPTC decode.
XorPayloadByte(Payload, 2, $5A);
DMRBPTC19696Encode(Payload, Burst);
PutCACH(Burst, $04);
PutSlotType(Burst, $91);
DMRParseBurst(Burst, Info);
Check(Info.LinkControl.Decoded and
(Info.LinkControl.RSCorrectedBytes = 1) and
(Info.LinkControl.ServiceOptions = $21), 'Full LC RS correction failed');
// Two damaged RS symbols exceed the RS(12,9) correction radius.
XorPayloadByte(Payload, 3, $A5);
DMRBPTC19696Encode(Payload, Burst);
PutSlotType(Burst, $91);
DMRParseBurst(Burst, Info);
Check(not Info.LinkControl.Decoded, 'invalid Full LC RS checksum accepted');
WriteLn('DMR CACH, Slot Type, BPTC and Full LC tests passed');
end.