To obviate the control of reflective intelligent surfaces (RISs) and the related control overhead, recent works envisioned autonomous and self-configuring RISs that do not need explicit use of control channels. Instead, these devices, named hybrid RISs (HRISs), are equipped with receiving radio-frequency (RF) chains and can perform sensing operations to act independently and in parallel to the other network entities. A natural problem then emerges: as the HRIS operates concurrently with the communication protocols, how should its operation modes be scheduled in time such that it helps the network while minimizing any undesirable effects? In this paper, we propose an orchestration framework that answers this question revealing an engineering trade-off, called the self-configuring trade-off, that characterizes the applicability of self-configuring HRISs under the consideration of massive multiple-input multiple-output (mMIMO) networks. We evaluate our proposed framework considering two different HRIS hardware architectures, the power- and signal-based HRISs that differ in their hardware complexity. The numerical results show that the self-configuring HRIS can offer significant performance gains when adopting our framework.

翻译：为消除反射智能表面（RIS）的控制需求及相关控制开销，近期研究提出了无需显式使用控制信道的自主自配置RIS。这类名为混合RIS（HRIS）的设备配备接收射频（RF）链路，可独立于其他网络实体并行执行感知操作。由此产生一个自然问题：当HRIS与通信协议并发运行时，应如何对其操作模式进行时间调度，使其在最大限度减少不良影响的同时辅助网络？本文提出一种编排框架来解答该问题，揭示了表征自配置HRIS在大规模多输入多输出（mMIMO）网络中适用性的工程权衡——自配置权衡。我们考虑两种硬件复杂度不同的HRIS架构（功率型与信号型）对所提框架进行评估。数值结果表明，采用本框架的自配置HRIS可带来显著的性能提升。