加权和码辅助的极化码SCL译码算法

Weighted sum codes-aided SCL decoding of polar codes

为了进一步降低极化码串行抵消列表译码算法的译码时延,提出了一种加权和码辅助的串行抵消列表译码算法。采用加权和码级联极化码的编码方案,将加权和码产生的校验比特与信息序列一同输入极化码编码器进行极化码编码。加权和码辅助的串行抵消列表译码算法是在原始的串行抵消列表译码后,使用加权和码对候选路径依次校验,选择置信度最高且通过校验的路径作为译码输出。与广泛应用的循环冗余校验码相比,加权和码有一致的检错性能,并且其编译码硬件实现的时延低。仿真结果表明,加权和码辅助的串行抵消列表译码算法与循环冗余校验码辅助的串行抵消列表译码算法相比较,性能曲线基本重合,且在很大程度上降低了译码的校验时延。

To further reduce the latency of succession cancellation list(SCL)decoding algorithm for polar codes,a weighted sum codes-aided SCL decoding algorithm is proposed.A concatenated coding scheme is designed which uses weighted sum codes as outer codes and polar codes as inner codes.The check bits generated by weighted sum coding and all information bits are put into the polar encoder.The modified weighted sum codes-aided SCL decoder feeds the candidate sequences into the weighted sum detector and outputs the one which fulfills the detector with highest reliability.Weighted sum codes combine the error detection properties of cyclic redundancy check with efficient hardware implementation.Simulation results show that the proposed scheme provides almost the same performance as the widely-used CRC-aided successive cancellation list decoding and that it considerably reduces the check latency without performance loss.