On the Application of the Fast Hadamard Transform in Polar Codes

Abstract

In this paper, we propose a low latency fast Hadamard transform (FHT) based decoder for polar codes. We show that while this decoder can achieve the same performance as the popular successive cancellation (SC) decoder, it is superior to the SC decoder in terms of latency. The proposed FHT decoder can be applied directly to most short Polar codes, but requires a modest level of encoder modification for relatively long codes. It will be shown that in the case when the encoder must be modified, the FHT decoder can also outperform the SC decoder.