A Novel Interleaving Scheme for Polar Codes

TL;DR

This paper introduces a new interleaving scheme for polar codes concatenated with LDPC codes, reducing error correlation and delay while maintaining simple decoding and achieving comparable BER performance.

Contribution

A novel interleaving scheme that breaks error correlation in polar-LDPC concatenation, improving delay and performance without complex decoding.

Findings

Reduces error correlation among polar code bits.

Achieves comparable BER performance with smaller delay.

Maintains simple SC decoding for polar codes.

Abstract

It's known that the bit errors of polar codes with successive cancellation (SC) decoding are coupled. We call the coupled information bits the correlated bits. In this paper, concatenation schemes are studied for polar codes (as inner codes) and LDPC codes (as outer codes). In a conventional concatenation scheme, to achieve a better BER performance, one can divide all $N_l$ bits in a LDPC block into $N_l$ polar blocks to completely de-correlate the possible coupled errors. In this paper, we propose a novel interleaving scheme between a LDPC code and a polar code which breaks the correlation of the errors among the correlated bits. This interleaving scheme still keeps the simple SC decoding of polar codes while achieves a comparable BER performance at a much smaller delay compared with a $N_l$-block delay scheme.