A Sequence Repetition Node-Based Successive Cancellation List Decoder for 5G Polar Codes: Algorithm and Implementation
Yuqing Ren, Andreas Toftegaard Kristensen, Yifei Shen, Alexios Balatsoukas‐Stimming, Chuan Zhang, Andreas Peter Burg · IEEE Transactions on Signal Processing · 2022
Due to the low-latency and high-reliability requirements of 5G, low-complexity node-based successive cancellation list (SCL) decoding has received considerable attention for use in 5G communications systems. By identifying special constituent codes in the decoding tree and immediately decoding these, node-based SCL decoding provides a significant reduction in decoding latency compared to conventional SCL decoding. However, while there exists many types of nodes, the current node-based SCL decoders are limited by the lack of a more generalized node that can efficiently decode a larger number of different constituent codes to further reduce the decoding time. In this paper, we extend a recent generalized node, the sequence repetition (SR) node, to SCL decoding, and describe the first implementation of an SR-List decoder. By merging certain SR-List decoding operations and applying various optimizations for 5G New Radio (NR) polar codes, our optimized SR-List decoding algorithm increases the throughput by almost$\bm {2\times }$compared to a similar state-of-the-art node-based SCL decoder. We also present our hardware implementation of the optimized SR-List decoding algorithm which supports all 5G NR polar codes. Synthesis results show that our SR-List decoder can achieve a$2.94 \,\mathrm{Gbps}$throughput and$6.70 \,\mathrm{Gbps}\mathrm{m}^{-1}\,\mathrm{m}^{2}\,$area efficiency for$\bm {L=8}$.