面向超对角堆叠智能超表面辅助的ISAC系统的联合功率分配与相移设计
Joint Power Allocation and Phase-Shift Design for Beyond-Diagonal Stacked Intelligent Metasurfaces-Aided ISAC Systems
中文总结 AI 辅助
该研究针对ISAC系统提出超对角堆叠智能超表面架构，开发统一交替优化框架及相关算法，仿真显示其可实现更优通信-感知权衡且所需层数更少。
中文摘要 AI 辅助
堆叠智能超表面（SIM）为集成感知与通信（ISAC）提供了一种高效架构，仅需少量射频（RF）链。然而，对角SIM仅能实现逐元件相位控制，因此平衡多用户通信与感知性能可能需要额外层。本论文提出一种用于ISAC的超对角SIM（BD-SIM）架构，其可通过可重构阻抗网络实现可控层内耦合，从而提升波域处理灵活性。我们开发了一种适用于全连接、组连接及对角SIM架构的统一交替优化框架，在该框架中推导了闭式功率分配规则，并提出一种用于多层相移设计的有效变量分离算法。仿真结果表明，所提BD-SIM可实现更优的通信-感知权衡，且达到与传统SIM相当性能所需的层数更少。
英文摘要
Stacked intelligent metasurfaces (SIM) provide an efficient architecture for integrated sensing and communication (ISAC) with few radio-frequency (RF) chains. However, diagonal SIM provide only element-wise phase control, so balancing multiuser communication and sensing performance may require additional layers. In this letter, we propose a beyond-diagonal SIM (BD-SIM) architecture for ISAC, enabling controllable intra-layer coupling through reconfigurable impedance networks, thereby enhancing wave-domain processing flexibility. We develop a unified alternating optimization framework applicable to fully-connected, group-connected, and diagonal SIM architectures. Within this framework, we derive a closed-form power allocation rule and propose an effective variable separation algorithm for multi-layer phase-shift design. Simulation results show that the proposed BD-SIM achieve a better communication-sensing trade-off and require fewer layers to attain performance comparable to conventional SIM.
