Rate-Compatible Polar Codes for Wireless Channels

TL;DR

This paper introduces a flexible, rate-compatible polar coding scheme for wireless channels that maintains polarization through puncturing and repetition, enhancing HARQ performance over various channel conditions.

Contribution

It proposes a low-complexity puncturing order for polar codes that preserves polarization, enabling adaptable rate-matching in HARQ systems with practical implementation.

Findings

Robust performance over AWGN and fading channels

Effective in Chase combining and incremental redundancy HARQ

Flexible rate adaptation with polarization preservation

Abstract

A design of rate-compatible polar codes suitable for HARQ communications is proposed in this paper. An important feature of the proposed design is that the puncturing order is chosen with low complexity on a base code of short length, which is then further polarized to the desired length. A practical rate-matching system that has the flexibility to choose any desired rate through puncturing or repetition while preserving the polarization is suggested. The proposed rate-matching system is combined with channel interleaving and a bit-mapping procedure that preserves the polarization of the rate-compatible polar code family over bit-interleaved coded modulation systems. Simulation results on AWGN and fast fading channels with different modulation orders show the robustness of the proposed rate-compatible polar code in both Chase combining and incremental redundancy HARQ communications.