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网络中核心的无线接入技术。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，旨在避免网络拥塞，并相较于传统IC系统提升频谱效率。本文提出了一种名为三组IC-NOMA的高频谱效率传输方案，并开发了一种符合NOMA解码原理的创新性索引码设计，以实现更高的频谱效率。通过详尽的分析研究，我们证明所提出的传输方案始终能支持比传统IC系统更高的速率，且达到与传统IC系统至少相同信息速率时所需功率更低。