This work addresses the comparison between active and passive RISs in wireless networks, with reference to the system energy efficiency (EE). To provably convergent and computationally-friendly EE maximization algorithms are developed, which optimize the reflection coefficients of the RIS, the transmit powers, and the linear receive filters. Numerical results show the performance of the proposed methods and discuss the operating points in which active or passive RISs should be preferred from an energy-efficient perspective.

翻译：摘要：本文针对无线网络中有源与无源可重构智能表面（RIS）的能效（EE）性能进行比较研究。为获得可证收敛且计算友好的能效最大化算法，我们开发了联合优化RIS反射系数、发射功率及线性接收滤波器的方案。数值结果展示了所提方法的性能，并从能效角度探讨了有源RIS与无源RIS的适用工作点。