Interleaved Local Sorting for Successive Cancellation List Decoding of Polar Codes

In the successive cancellation list decoding of polar codes, the metric sorting dominates the overall decoding latency. To reduce the latency of metric sorting, this paper proposes a new sorting method, called interleaved local sorting, which divides the metrics to be sorted into several groups and locally sorts each group independently. In addition, an interleaving scheme is proposed to recover the performance degradation caused by the local sorting. A hardware architecture effective in reducing the overall latency as well as the hardware complexity is also proposed based on the proposed metric sorting. The evaluation results show that the proposed interleaved local sorting architecture outperforms the state-of-the-art metric sorting architectures in terms of latency and hardware complexity when the list size is not small.