Reduced complexity list polar decoder with an improved path pruning scheme
Zhiyu Chen, Jun Ting Lin, Zhongfeng Wang · 2017
While the cyclic redundancy check (CRC) aided successive cancellation list (SCL) decoding algorithm for polar codes outperforms the successive cancellation (SC) decoding algorithm in terms of error correction capability, it still has long decoding latency. To accelerate the decoding process, a high throughput list decoder architecture was proposed, which enables the list decoder to partially work in parallel. However, a large sorting space is required in this method and the sorting procedure is relatively time-consuming. In this paper, a hamming distance filter (HDF) algorithm is proposed to reduce sorting complexity during the decoding path pruning. Based on the proposed HDF algorithm, if a path has a large hamming distance (larger than a predefined threshold) between the hard decision of the received LLR and its corresponding constituent code, it is simply discarded. Supposing a HDF aided list decoder is used for an (8192,4096) polar code, simulation results demonstrate that the reduction of the sorting space varies from approximately 36% to 70% with negligible error performance loss.