Real-time adaptive optimization of average peak age of information in SWIPT-based cooperative WSN deploying NOMA

Abstract

This paper investigates the average peak age-of-information (APAoI) in a cooperative wireless sensor network (WSN), which deploys non-orthogonal multiple access (NOMA) and simultaneous wireless information and power transfer (SWIPT) techniques. To assist the poor source–destination direct link, the relay can utilize the harvested energy to decode the superposition-coded signal sent by the source and send its decoded information to the remote destination. With the aim of minimizing APAoI for long-term transmission, we formulate an energy allocation policy problem to trade off rate, energy, and time under certain constraints. To overcome the difficulties caused by time-varying parameters and non-convexity constraints, we perform a quasi-static transformation to obtain a simplified optimization model and some energy allocation criteria. Based on this work, we propose a heuristic APAoI real-time adaptive optimization (APRAO) algorithm that decomposes the original problem into multiple sub-problems for each transmission. During the sub-problem solving process, we introduce the static energy allocation criteria, which let the obtained solutions help our APRAO algorithm track the optimal solution as the transmission number increases. Finally, we evaluate and verify the performance of the proposed algorithm through numerical experiments.

Keywords

• Power transfer
• Average peak age-of-information
• Non-orthogonal multiple access
• Cooperative relaying network