论文标题
混合RIS中的波束辅助综合感应和通信系统
Beamforming in Hybrid RIS assisted Integrated Sensing and Communication Systems
论文作者
论文摘要
在本文中，我们考虑了由主动和被动元素组成的混合智能表面（RIS），以帮助综合的感应和通信（ISAC）系统，为多个用户和目标提供服务。混合RIS中的活性元素包括放大器和相移，而被动元件仅包括相变。我们共同设计传输光束形成器和RIS系数，即放大器的增益和相移，以最大化最坏情况的目标照明功率，同时确保通信链路的所需信号与互换比率，并限制由于主动元素而引起的RIS噪声功率。由于此设计问题不是凸，因此我们提出了一个基于交替优化的求解器，以设计发射光束形成器和RIS系数。通过数值模拟，我们证明了所提出的混合RIS辅助ISAC系统的性能明显优于被动RIS辅助ISAC系统以及没有RIS的ISAC系统，即使只有一小部分混合RIS包含活性元素。
In this paper, we consider a hybrid reconfigurable intelligent surface (RIS) comprising of active and passive elements to aid an integrated sensing and communication (ISAC) system serving multiple users and targets. Active elements in a hybrid RIS include amplifiers and phase shifters, whereas passive elements include only phase shifters. We jointly design transmit beamformers and RIS coefficients, i.e., amplifier gains and phase shifts, to maximize the worst-case target illumination power while ensuring a desired signal-to-interference-plus-noise ratio for communication links and constraining the RIS noise power due to the active elements. Since this design problem is not convex, we propose a solver based on alternating optimization to design the transmit beamformers and RIS coefficients. Through numerical simulations, we demonstrate that the performance of the proposed hybrid RIS assisted ISAC system is significantly better than that of passive RIS assisted ISAC systems as well as ISAC systems without RIS even when only a small fraction of the hybrid RIS contains active elements.
