论文标题
优化基于NOMA的IoT网络中的信息新鲜度
Optimizing Information Freshness in RIS-assisted NOMA-based IoT Networks
论文作者
论文摘要
本文研究了整合可重构智能表面（RIS）的好处，以最大程度地降低上行链路非链接多个基于多访问的基于基于多访问的信息（IoT）网络中信息总和（AOI）的好处。在此设置中，制定了一个优化问题，以优化RIS配置，每个IoT设备的传输功率以及IoT设备的聚类策略。公式化的问题是混合企业非凸台，为了解决该问题，我们首先通过采用半明确放松（SDR）方法获得了RIS配置。之后，使用BI级优化的概念解决了关节功率分配和用户聚类问题，并将其分解为外部用户聚类问题和内部功率分配问题。为内部问题得出了最佳的闭合表达式，并采用了匈牙利方法来解决外部问题。数值结果证明了我们方法的性能优势。
This paper investigates the benefits of integrating reconfigurable intelligent surface (RIS) on minimizing the average sum age of information (AoI) in uplink non-orthogonal multiple access-based Internet-of-Things (IoT) networks. In this setup, an optimization problem is formulated to optimize the RIS configuration, the transmit power per IoT device and the clustering policy of IoT devices. The formulated problem is a mixed-integer non-convex one, and in order to solve it we obtain first the RIS configuration by adopting a semi-definite relaxation (SDR) approach. Afterwards, the joint power allocation and user-clustering problem is solved using the concept of bi-level optimization and is decomposed into an outer user clustering problem and an inner power allocation problem. Optimal closed-form expressions are derived for the inner problem and the Hungarian method is employed to solve the outer one. Numerical results demonstrate the performance superiority of our approach.
