Hybrid Active-and-Passive Relay Network Optimization of mmWave Communications for Industrial Internet

Abstract

Multi-hop relay selection is regarded as a key technology to overcome severe path loss and adapt complex environments in millimeter-wave (mmWave) and terahertz communication. Meanwhile, new hardware called reconfigurable intelligent surface (RIS) has emerged and is used to boost the spectral and energy efficiency of future wireless communication systems. Then, to solve the challenge that the numerous energy consumption caused by the increasing number of relays in the future industrial internet a promising architecture with a hybrid active–and-passive relay network is proposed in this paper. Then, the optimization joint system delay and energy efficiency based on the simulated annealing (SA) algorithm is considered in this paper. A hierarchical heuristic optimization algorithm with lower complexity is proposed and proved to be feasible under good communication conditions compared with other algorithms. Finally, numerical results demonstrate that the proposed hybrid relay system and joint optimization model can improve the energy efficiency of the network and reduce the system delay.