This paper investigates how to apply non-orthogonal multiple access (NOMA) as an add-on in terahertz (THz) networks. In particular, prior to the implementation of NOMA, it is assumed that there exists a legacy THz system, where spatial beams have already been configured to serve legacy primary users. The aim of this paper is to study how these pre-configured spatial beams can be used as a type of bandwidth resources, on which additional secondary users are served without degrading the performance of the legacy primary users. A joint beam management and power allocation problem is first formulated as a mixed combinatorial non-convex optimization problem, and then solved by two methods with different performance-complexity tradeoffs, one based on the branch and bound method and the other based on successive convex approximation. Both analytical and simulation results are presented to illustrate the new features of beam-based resource allocation in THz-NOMA networks and also demonstrate that those pre-configured spatial beams can be employed to improve the system throughput and connectivity in a spectrally efficient manner.
翻译:本文调查了如何将非垂直多重存取(NOMA)作为一种附加手段应用于Teahertz(THz)网络,特别是在实施NOMA之前,假定存在着遗留的THz系统,空间光束已经配置,为遗留的主要用户服务。本文的目的是研究这些预先配置的空间光束如何用作带宽资源的一种类型,为更多的二级用户提供服务,同时又不降低遗留的主要用户的性能。首先,将联合波束管理和电力分配问题作为混合组合式非螺旋优化问题,然后用两种方法以不同的性能兼容性权衡法来解决,一种基于分支和约束法,另一种基于连续的convex近似法。提出了分析和模拟结果,以说明THz-NOMA网络基于光谱的资源分配的新特点,并表明这些预先配置的空间束可以通过光谱高效的方式进行翻转和连接来改进系统。