Low-latency software successive cancellation list polar decoder using stage-located copy

Successive cancellation list (SCL) decoding for polar codes is promising in data communication. However, in addition to L times complexity of conventional SC, both path selecting and updating result in extra complexity. In detail, the copy of intermediate values suffers from a long latency, especially when list size L is large. In this paper, a stage-located copy algorithm is proposed to avoid copying the same contents in candidate paths, which significantly reduces the processing latency. Furthermore, the resulting data processing speedup increases with code length. For (2048, 1723) polar codes, experimental results have shown that by employing the proposed stage-located copy, throughput of software-based SCL decoder with L = 32 achieves up to 1.1 Mbps throughput with 45% increase compared to the state-of-the-art software SCL decoders.