Channel Coding Toward 6G: Technical Overview and Outlook
Mohammad Rowshan, Min Qiu, Yixuan Xie, Xinyi Gu, Jinhong Yuan
TL;DR
This paper surveys channel coding for 6G, detailing how LDPC, Turbo, and Polar codes (plus alternatives) shape key KPIs such as reliability, latency, and spectral/energy efficiency, and projects 6G requirements with a focus on finite‑length performance. It traces the evolution from 1G to 5G/5G‑Advanced, clarifying how standardization (3GPP, ITU) and evolving use cases drive coding choices, including LDPC data channels and Polar control channels in 5G NR and the move toward 6G concepts. The Turbo/LDPC/Polar sections provide deep dives into code constructions, interleaving/puncturing, decoding algorithms, and hardware architectures, highlighting threshold behaviors, error floors, and throughput targets up to multi‑Gb/s and beyond. The report emphasizes spatial coupling, protograph designs, rate‑matching, and unified reconfigurable decoders as promising directions for 6G, with finite‑blocklength/throughput analyses (NA, DE, EXIT/PEXIT) guiding practical implementations. Overall, the work maps a trajectory from mature 5G techniques toward 6G‑level reliability and latency goals, offering concrete design tools and future research directions for high‑throughput, low‑latency, and energy‑efficient channel coding.
Abstract
Channel coding plays a pivotal role in ensuring reliable communication over wireless channels. With the growing need for ultra-reliable communication in emerging wireless use cases, the significance of channel coding has amplified. Furthermore, minimizing decoding latency is crucial for critical-mission applications, while optimizing energy efficiency is paramount for mobile and the Internet of Things (IoT) communications. As the fifth generation (5G) of mobile communications is currently in operation and 5G-advanced is on the horizon, the objective of this paper is to assess prominent channel coding schemes in the context of recent advancements and the anticipated requirements for the sixth generation (6G). In this paper, after considering the potential impact of channel coding on key performance indicators (KPIs) of wireless networks, we review the evolution of mobile communication standards and the organizations involved in the standardization, from the first generation (1G) to the current 5G, highlighting the technologies integral to achieving targeted KPIs such as reliability, data rate, latency, energy efficiency, spectral efficiency, connection density, and traffic capacity. Following this, we delve into the anticipated requirements for potential use cases in 6G. The subsequent sections of the paper focus on a comprehensive review of three primary coding schemes utilized in past generations and their recent advancements: low-density parity-check (LDPC) codes, turbo codes (including convolutional codes), polar codes (alongside Reed-Muller codes). Additionally, we examine alternative coding schemes like Fountain codes and sparse regression codes. Our evaluation includes a comparative analysis of error correction performance and the performance of hardware implementation for these coding schemes, providing insights into their potential and suitability for the upcoming 6G era.