Sum-Rate Maximization for STAR-RIS-Assisted Multi-User Networks With Hardware Impairments

作者：Xiaomei Luo, Zhuochen Jiang, Fan Xu, Xiaoyang Li, Guangxu Zhu, Kaiming Shen · 发表于：IEEE Wireless Communications Letters · 年份：2024 · DOI：10.1109/lwc.2024.3378846 · 被引用次数：7 · 研究领域：Advanced Wireless Communication Technologies、Indoor and Outdoor Localization Technologies、Underwater Vehicles and Communication Systems

Hardware impairments can substantially limit the performance gain brought by the simultaneous transmitting and reflecting reconfigurable intelligent surface (STAR-RIS). To address the above issue, this letter advocates a robust beamforming method for STAR-RIS in conjunction with the active beamforming at the base station for maximizing the sum-rate throughout the network. There are three main results. First, we extend the well-known weighted sum mean-square error minimization (WMMSE) method to the STAR-RIS beamforming with the hardware impairments taken into account. Then, the Schur’s complement and the first-order Taylor expansion are adopted to successively approximate the non-convex problem as a jointly convex problem of the amplitude and the phase variables. Furthermore, we propose a computationally efficient gradient projection method that optimizes the amplitude and phase alternately. Simulations demonstrate the effectiveness and robustness of the proposed algorithms in boosting the overall network throughput in the presence of hardware impairments.