An Online Decoding Schedule Generating Algorithm for Successive Cancellation Decoder of Polar Codes

TL;DR

This paper introduces a simple, online algorithm for generating decoding schedules for the successive cancellation decoder of polar codes, reducing complexity and memory usage compared to existing methods.

Contribution

It presents a novel online decoding schedule generation algorithm based on sharing factors, improving efficiency and memory footprint over traditional recursive or traversal-based methods.

Findings

The algorithm is online and does not require offline precomputation.

It significantly reduces memory consumption for decoding schedules.

The proposed method outperforms existing algorithms in efficiency and simplicity.

Abstract

Successive cancellation (SC) is the first and widely known decoder of polar codes, which has received a lot of attentions recently. However, its decoding schedule generating algorithms are still primitive, which are not only complex but also offline. This paper proposes a simple and online algorithm to generate the decoding schedule of SC decoder. Firstly, the dependencies among likelihood ratios (LR) are explored, which lead to the discovery of a sharing factor. Secondly, based on the online calculation of the sharing factor, the proposed algorithm is presented, which is neither based on the depth-first traversal of the scheduling tree nor based on the recursive construction. As shown by the comparisons among the proposed algorithm and existed algorithms, the proposed algorithm has advantages of the online feature and the far less memory taken by the decoding schedule.