Intelligent reflecting surfaces (IRSs), active and/or passive, can be densely deployed in complex environments to significantly enhance wireless network coverage for both wireless information transfer (WIT) and wireless power transfer (WPT). In this letter, we study the downlink WIT/WPT from a multi-antenna base station to a single-antenna user over a multi-active/passive IRS (AIRS/PIRS)-enabled wireless link. In particular, we aim to optimize the location of the AIRS with those of the other PIRSs being fixed to maximize the received signal-to-noise ratio (SNR) and signal power at the user in the cases of WIT and WPT, respectively. We derive the optimal solutions for these two cases in closed-form, which reveals that the optimal AIRS deployment is generally different for WIT versus WPT. Furthermore, both analytical and numerical results are provided to show the conditions under which the proposed AIRS deployment strategy yields superior performance to other baseline deployment strategies as well as the conventional all- PIRS enabled WIT/WPT.
翻译:动态和/或被动的智能反射表面(IRS)可以在复杂环境中密集地部署,以大幅度增强无线网络覆盖无线信息传输和无线电源传输的无线网络,在本信中,我们研究了多防天线基地站向单防天线用户的下行链路WIT/WPT在多动/被动的IRS(AIRS/PIRS)驱动的无线链接上的情况,特别是,我们的目标是优化AIRS与其他固定的PIRS的位置,以在WIT和WPT中分别最大限度地提高收到的信号对噪音比率和用户的信号功率,我们以封闭式方式为这两种情况找到最佳解决办法,表明对多防天线通信/被动的IRS部署与WPT的部署通常不同。此外,我们提供了分析和数字结果,以显示拟议的AIRS部署战略取得优于其他基线部署战略的条件,以及所有常规的PIRS启用的WIT/WPT。