In this work, a novel time and relay shared (TRS) based full/half duplex (FD/HD) cooperative non-orthogonal multiple access (C-NOMA) scheme namely TRS FD/HD C-NOMA is proposed to efficiently exploit the spectrum of unpaired users in the wireless communication system. More specifically, a scenario has been investigated where cell edge users (CEUs) are more than the cell centre users (CCUs) and the base station has no direct connection with the CEUs. A CCU is employed as a shared relay to form clusters with the CEUs in a time-sharing fashion. To characterize the performance of the proposed scheme, four performance metrics ergodic capacity, outage probabilities, system throughput and system efficiency are discussed. More particularly, ergodic sum capacities are analytically derived and an exact closed-form expression of the outage probabilities is derived for three users in the system. Numerical results show that the TRS FD/HD C-NOMA scheme outperforms the conventional benchmarks. The ergodic capacities and outage performance of TRS FD C-NOMA enhanced in low SNR regime whereas due to the inclusion of loop interference in FD, TRS HD C-NOMA performs better in high SNR regime. Additionally, the system throughput and efficiency are also improved.

中文翻译：

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与成对小区边缘用户共享时间和中继的全/半双工协作 NOMA

在这项工作中，提出了一种基于时间和中继共享（TRS）的新型全/半双工（FD/HD）协作非正交多址（C-NOMA）方案，即TRS FD/HD C-NOMA，以有效利用频谱无线通信系统中未配对的用户的数量。更具体地，已经研究了小区边缘用户（CEU）多于小区中心用户（CCU）并且基站与CEU没有直接连接的场景。CCU 用作共享中继，以分时方式与 CEU 形成集群。为了表征所提出方案的性能，讨论了四个性能指标：遍历容量、中断概率、系统吞吐量和系统效率。更具体地，分析地导出遍历总和容量并且导出系统中的三个用户的中断概率的精确封闭形式表达式。数值结果表明，TRS FD/HD C-NOMA 方案优于传统基准。TRS FD C-NOMA 的遍历容量和中断性能在低 SNR 范围内得到增强，而由于 FD 中包含环路干扰，TRS HD C-NOMA 在高 SNR 范围内表现更好。此外，系统吞吐量和效率也得到提高。