Index coding (IC) is a source coding technique employed to improve spectral utilisation, where the source node aims to satisfy users' demands by making minimum transmissions. Non-orthogonal multiple access (NOMA) is integral to the radio access technique used in 5G networks. Index-coded NOMA (IC-NOMA) transmission scheme in Vehicular Adhoc Networks (VANETs) involves applying NOMA principles on index-coded data to avoid network congestion and to improve spectral efficiency compared to conventional IC systems. In this work, a spectral efficient transmission scheme called 3-Group IC-NOMA is proposed, and an innovative index code design that fits with NOMA decoding principles to obtain improved spectral efficiency is developed. Through exhaustive analytical studies, we demonstrate that the proposed transmission scheme always supports higher rates than the conventional IC systems and requires less power to achieve an information rate at least as good as conventional IC systems.

翻译：索引编码（IC）是一种用于提升频谱利用率的信源编码技术，其中源节点旨在通过最小化传输次数来满足用户需求。非正交多址接入（NOMA）是5G网络采用的无线接入技术的关键组成部分。车载自组织网络（VANETs）中的索引编码-非正交多址接入（IC-NOMA）传输方案，通过将NOMA原理应用于索引编码数据，相较于传统IC系统，能够避免网络拥塞并提升频谱效率。本文提出了一种名为3组IC-NOMA的频谱高效传输方案，并开发了一种创新的索引码设计，该设计契合NOMA解码原理以实现更优的频谱效率。通过详尽的分析研究，我们证明所提出的传输方案始终支持比传统IC系统更高的速率，并且在达到至少与传统IC系统相当的信息速率时，所需功率更低。