ABSTRACT

Non-orthogonal multiple access (NOMA) and full-duplex (FD) have recently emerged as a potential candidate for the fifth-generation and beyond (B5G) cellular networks with the target of increasing spectral efficiency and guaranteeing the quality-of-services (QoS). This paper proposes an orthogonal frequency division multiple access (OFDMA) based FD cooperative device-to-device (C-D2D) communications system, wherein a D2D transmitter (DT) acts as an FD relay to support simultaneous bidirectional communication between a base station (BS) and a cellular user (CU). In addition, a power splitting protocol using NOMA is incorporated for the FD C-D2D system to share the resources between the cellular and D2D user. Further, the successive interference cancellation (SIC) is used to decode the signals, while self-interference suppression (SIS) is employed at DT to mitigate self-interference (SI). The analytical expressions for achievable rates of the cellular and D2D links and their outage probabilities for the FD and half-duplex (HD) systems are derived. Outage trade-offs between FD/HD relaying have been analyzed. Results show that the proposed model enhances the overall outage performance of the cellular and D2D users. Moreover, for high cellular outage constraints, DT as an FD relay outperforms the conventional HD C-D2D communications system wherein DT acts as an HD relay.

摘要

非正交多址接入 (NOMA) 和全双工 (FD) 最近已成为第五代及以后 (B5G) 蜂窝网络的潜在候选者，其目标是提高频谱效率并保证服务质量 (服务质量）。本文提出了一种基于正交频分多址（OFDMA）的 FD 协作设备到设备（C-D2D）通信系统，其中 D2D 发射机（DT）充当 FD 中继以支持基站（ BS）和蜂窝用户（CU）。此外，FD C-D2D 系统还采用了使用 NOMA 的功率分配协议，以共享蜂窝和 D2D 用户之间的资源。此外，连续干扰消除（SIC）用于解码信号，而 DT 采用自干扰抑制 (SIS) 来减轻自干扰 (SI)。导出了蜂窝和 D2D 链路可实现速率的解析表达式及其 FD 和半双工 (HD) 系统的中断概率。已经分析了 FD/HD 中继之间的中断权衡。结果表明，所提出的模型增强了蜂窝和 D2D 用户的整体中断性能。此外，对于高蜂窝中断限制，作为 FD 中继的 DT 优于传统的 HD C-D2D 通信系统，其中 DT 充当 HD 中继。结果表明，所提出的模型增强了蜂窝和 D2D 用户的整体中断性能。此外，对于高蜂窝中断限制，作为 FD 中继的 DT 优于传统的 HD C-D2D 通信系统，其中 DT 充当 HD 中继。结果表明，所提出的模型增强了蜂窝和 D2D 用户的整体中断性能。此外，对于高蜂窝中断限制，作为 FD 中继的 DT 优于传统的 HD C-D2D 通信系统，其中 DT 充当 HD 中继。