aicodix___code/pac_encoder.hh

39 lines
869 B
C++

/*
Encoder for Polarization-Adjusted Convolutional codes
Copyright 2025 Ahmet Inan <inan@aicodix.de>
*/
#pragma once
#include "polar_helper.hh"
namespace CODE {
template <typename TYPE>
class PACEncoder
{
typedef PolarHelper<TYPE> PH;
static bool get(const uint32_t *bits, int idx)
{
return (bits[idx/32] >> (idx%32)) & 1;
}
public:
void operator()(TYPE *codeword, const TYPE *message, const uint32_t *frozen, int level)
{
int length = 1 << level;
for (int i = 0; i < length; i += 2) {
TYPE msg0 = get(frozen, i) ? PH::one() : *message++;
TYPE msg1 = get(frozen, i+1) ? PH::one() : *message++;
codeword[i] = PH::qmul(msg0, msg1);
codeword[i+1] = msg1;
}
for (int h = 2; h < length; h *= 2)
for (int i = 0; i < length; i += 2 * h)
for (int j = i; j < i + h; ++j)
codeword[j] = PH::qmul(codeword[j], codeword[j+h]);
}
};
}