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added 16 bit CRC

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This commit is contained in:
Ahmet Inan 2025-07-17 12:00:44 +02:00
commit b8fb5e7dd6
3 changed files with 9 additions and 8 deletions
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5
common.hh
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@ -32,7 +32,8 @@ struct Common
static constexpr int slm_poly[16] = {
0x11d, 0x12b, 0x12d, 0x14d, 0x15f, 0x163, 0x165, 0x169,
0x171, 0x187, 0x18d, 0x1a9, 0x1c3, 0x1cf, 0x1e7, 0x1f5 };
CODE::CRC<uint32_t> crc0;
CODE::CRC<uint16_t> crc0;
CODE::CRC<uint32_t> crc1;
CODE::HadamardEncoder<6> hadamard_encoder;
int8_t head[32];
int8_t tail[32];
@ -49,7 +50,7 @@ struct Common
int symbol_count;
bool differential;
Common() : crc0(0x8F6E37A0) {}
Common() : crc0(0xA8F4), crc1(0x8F6E37A0) {}
void setup(int mode)
{

6
decode.cc
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@ -372,10 +372,10 @@ struct Decoder : Common
polar_decoder(nullptr, mesg, code, frozen_bits, code_order);
int best = -1;
for (int k = 0; k < mesg_type::SIZE; ++k) {
crc0.reset();
crc1.reset();
for (int i = 0; i < crc_bits; ++i)
crc0(mesg[i].v[k] < 0);
if (crc0() == 0) {
crc1(mesg[i].v[k] < 0);
if (crc1() == 0) {
best = k;
break;
}

6
encode.cc
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@ -273,11 +273,11 @@ struct Encoder : public Common
schmidl_cox();
for (int i = 0; i < data_bits; ++i)
mesg[i] = nrz(CODE::get_le_bit(data, i));
crc0.reset();
crc1.reset();
for (int i = 0; i < data_bytes; ++i)
crc0(data[i]);
crc1(data[i]);
for (int i = 0; i < 32; ++i)
mesg[i+data_bits] = nrz((crc0()>>i)&1);
mesg[i+data_bits] = nrz((crc1()>>i)&1);
polar_encoder(code, mesg, frozen_bits, code_order);
shuffle(perm, code, code_order);
CODE::MLS seq1(mls1_poly);