This paper presents an algorithm for finding the optimal configuration of active reconfigurable intelligent surface (RIS) when both transmitter and receiver are equipped with a single antenna each. The resultant configuration is globally optimal and it takes linear time for the computation. Moreover, there is a closed-form expression for the optimal configuration when the direct link vanishes, which enables further analysis.

翻译：本文提出了一种算法，用于在发射机和接收机均配备单天线的情况下，求解有源可重构智能表面（RIS）的最优配置。所得配置具有全局最优性，且计算时间复杂度为线性。此外，当直射链路消失时，最优配置存在闭式表达式，从而可进行进一步分析。