Efficient Sorting Architecture for Successive-Cancellation-List Decoding of Polar Codes

This brief presents an efficient sorting architecture for successive-cancellation-list decoding of polar codes. In order to avoid performing redundant sorting operations on the metrics that are already sorted in the previous step of decoding, the proposed architecture separately processes the sorted metrics and unsorted ones. In addition, the odd–even sort network is adopted as a basic building block to further reduce the hardware complexity while sustaining low latencies for various list sizes. On average, the proposed architecture requires less than 50% of the compare-and-swap units demanded by the area-efficient sorting networks in the literature.