Hybrid Active-Passive IRS Assisted Energy-Efficient Wireless Communication
Abstract
Deploying active reflecting elements at the intelligent reflecting surface (IRS) increases signal amplification capability but incurs higher power consumption. Therefore, it remains a challenging and open problem to determine the optimal number of active/passive elements for maximizing energy efficiency (EE). To answer this question, we consider a hybrid active-passive IRS (H-IRS) assisted wireless communication system, where the H-IRS consists of both active and passive reflecting elements.Specifically, we study the optimization of the number of active/passive elements at the H-IRS to maximize EE. To this end, we first derive the closed-form expression for a near-optimal solution under the line-of-sight (LoS) channel case and obtain its optimal solution under the Rayleigh fading channel case. Then, an efficient algorithm is employed to obtain a high-quality sub-optimal solution for the EE maximization under the general Rician channel case. Simulation results demonstrate the effectiveness of the H-IRS for maximizing EE under different Rician factors and IRS locations.
Cite
@article{arxiv.2305.01924,
title = {Hybrid Active-Passive IRS Assisted Energy-Efficient Wireless Communication},
author = {Qiaoyan Peng and Qingqing Wu and Guangji Chen and Ruiqi Liu and Shaodan Ma and Wen Chen},
journal= {arXiv preprint arXiv:2305.01924},
year = {2023}
}