Low-Latency Segmented List-Pruning Software Polar List Decoder
Yifei Shen, Liping Li, Junmei Yang, Xiaosi Tan, Zaichen Zhang, Xiaohu You, Chuan Zhang · IEEE Transactions on Vehicular Technology · 2020
As the first provably capacity-achieving codes, polar codes have been selected as the coding scheme for 5G enhanced mobile broadband (eMBB) control channels. Furthermore, if the bottleneck in decoding complexity is addressed, polar codes are still promising for long code length scenarios in the future with superior error-correcting performance. Considering the demand of cloud radio access network (C-RAN) in 5G system, the low-latency software polar decoder is studied in this paper. Two novel algorithms are proposed to reduce the latency of the successive cancellation list (SCL) decoding, including the segmented list-pruning (SLP) algorithm and the modified distributed sorting (MDS) algorithm. Moreover, the proposed SLP algorithm improves the decoding performance compared to existing segmentation schemes. In terms of the software implementation, our decoder is nearly 20% faster than the state-of-the-art flexible software polar list decoder.