此来源探讨了对角线外可重构智能表面（BD-RIS）在多用户多天线通信网络中的应用。文章提出了一种名为 FP-PSLA 的新型优化算法，旨在解决现有 BD-RIS 辅助系统中 有源和无源波束赋形联合优化所面临的复杂性挑战。该算法通过采用迭代闭式解，显著降低了计算时间，同时实现了接近最优的加权和速率性能。通过将所提出的方法与现有基线进行比较，研究结果强调了 FP-PSLA 在提高效率和保持高性能方面的优势，为 BD-RIS 在实际应用中的潜力提供了支持。

Joint Active and Passive Beamforming Optimization for Beyond Diagonal RIS-Aided Multi-User Communications

Abstract:

Benefiting from its capability to generalize existing reconfigurable intelligent surface (RIS) architectures and provide additional design flexibility via interactions between RIS elements, beyond-diagonal RIS (BD-RIS) has attracted considerable research interests recently. However, due to the symmetric and unitary passive beamforming constraint imposed on BD-RIS, existing joint active and passive beamforming optimization algorithms for BD-RIS either exhibit high computational complexity to achieve near optimal solutions or rely on heuristic algorithms with substantial performance loss. In this letter, we address this issue by proposing an efficient optimization framework for BD-RIS assisted multi-user multi-antenna communication networks. Specifically, we solve the weighted sum rate maximization problem by introducing a novel beamforming optimization algorithm that alternately optimizes active and passive beamforming matrices using iterative closed-form solutions. Numerical results demonstrate that our algorithm significantly reduces computational complexity while ensuring a sub-optimal solution.

Published in: IEEE Communications Letters ( Volume: 29, Issue: 3, March 2025)

Page(s): 517 - 521

Date of Publication: 13 January 2025

ISSN Information:

Print ISSN: 1089-7798

Electronic ISSN: 1558-2558

CD: 2373-7891

DOI: 10.1109/LCOMM.2025.3528968

Publisher: IEEE

Funding Agency:

10.13039/501100001809-National Nature Science Foundation of China (Grant Number: 62201347)

Shanghai Sailing Program (Grant Number: 22YF1428400)

Research Council of Finland through 6G Flagship (Grant Number: 346208)

DIRECTION (Grant Number: 354901)