发表机构
School of Electronic and Information Engineering, Beihang University（北京航空航天大学电子工程学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文针对连续透射可重构智能表面辅助的多用户下行通信，提出联合优化有限维预编码器与无限维相位函数的交替算法，实现性能提升。
AI 中文摘要
本文研究了连续透射可重构智能表面（CT-RIS）辅助的多用户下行链路通信，其中无源波束成形由定义在连续孔径上的相位函数表征。我们针对基站（BS）到CT-RIS链路采用距离相关的球面波模型，并针对CT-RIS到用户链路引入基于场响应矢量的有限路径模型。由此产生的加权和速率最大化问题联合优化有限维的BS预编码器和无限维的CT-RIS相位函数，形成一个混合有限维和无限维的非凸优化问题。为解决该问题，我们开发了一种交替优化算法，该算法结合了闭式BS预编码器更新与基于变分法和最小化-最大化方法推导的功能相位更新。数值结果表明，所提出的CT-RIS始终优于所考虑的基准方案，其性能增益归因于空间连续的相位控制和更大的有效接收面积。
英文摘要
This paper studies continuous transmissive reconfigurable intelligent surface (CT-RIS)-enabled multiuser downlink communications, where passive beamforming is characterized by a phase function defined over the continuous aperture. We employ a distance-dependent spherical-wave model for the base station (BS)-to-CT-RIS link and introduce a finite-path model based on field-response vectors for the CT-RIS-to-user links. The resulting weighted sum rate maximization problem jointly optimizes the finite-dimensional BS precoders and the infinite-dimensional CT-RIS phase function, giving rise to a mixed finite- and infinite-dimensional non-convex optimization problem. To address this problem, we develop an alternating optimization algorithm that combines a closed-form BS precoder update with a functional phase update derived using the calculus of variations and minorization-maximization. Numerical results demonstrate that the proposed CT-RIS consistently outperforms the considered benchmarks, with the performance gains attributed to spatially continuous phase control and a larger effective receiving area.
