Partitioned Successive-Cancellation List Flip Decoding of Polar Codes

TL;DR

This paper introduces a partitioned decoding method for polar codes that enhances error correction and reduces decoding time by applying SCLF to partitions, with tailored CRC design to mitigate collisions.

Contribution

It proposes the Partitioned SCLF decoding algorithm with a new partition design and CRC support, improving error correction and reducing complexity compared to traditional SCLF.

Findings

Error-correction gain of up to 0.15 dB over SCLF.

CRC structure reduces error loss at low FER, gaining 0.2 dB at FER=10^-4.

Decoding time is 1.5 times lower than SCLF, matching latency at FER=4×10^-3.

Abstract

The recently proposed Successive-Cancellation List Flip (SCLF) decoding algorithm for polar codes improves the error-correcting performance of state-of-the-art SC List (SCL) decoding. However, it comes at the cost of a higher complexity. In this paper, we propose the Partitioned SCLF decoding algorithm, an algorithm that divides a word in partitions and applies SCLF decoding to each partition separately. Compared to SCLF, PSCLF allows early termination but is more susceptible to cyclic-redundancy check (CRC) collisions. In order to maximize the coding gain, a new partition design tailored to PSCLF is proposed as well as the possibility to support different CRC lengths. Numerical results show that the proposed PSCLF algorithm has an error-correction performance gain of up to 0.15 dB with respect to SCLF. Moreover, the proposed CRC structure permits to mitigate the error-correction loss at low frame-error rate (FER) due to CRC collisions, showing a gain of 0.2 dB at $\text{FER}=10^{-4}$ with respect to the regular CRC structure. The average execution time of PSCLF is shown to be 1.5 times lower than that of SCLF, and matches the latency of SCLF at $\text{FER}=4\cdot10^{-3}$ and lower.