Next-generation wireless networks are expected to utilize limited radio frequency (RF) resources more efficiently with the aid of intelligent transceivers. To this end, we propose a promising transceiver architecture relying on stacked intelligent metasurfaces (SIM). An SIM is constructed by stacking an array of programmable metasurface layers, where each layer consists of a massive number of low-cost passive meta-atoms that individually manipulate the electromagnetic (EM) waves. By appropriately configuring the passive meta-atoms, an SIM is capable of accomplishing advanced computation and signal processing tasks, such as multiple-input multiple-output (MIMO) precoding/combining, multi-user interference mitigation, and radar sensing, as the EM wave propagates through the multiple layers of the metasurface, which effectively reduces both the RF-related energy consumption and processing delay. Inspired by this, we provide an overview of the SIM-aided MIMO transceiver design, which encompasses its hardware architecture and its potential benefits over state-of-the-art solutions. Furthermore, we discuss promising application scenarios and identify the open research challenges associated with the design of advanced SIM architectures for next-generation wireless networks. Finally, numerical results are provided for quantifying the benefits of wave-based signal processing in wireless systems.

中文翻译：

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堆叠式智能超表面辅助 MIMO 收发器设计


下一代无线网络有望在智能收发器的帮助下更有效地利用有限的射频 (RF) 资源。为此，我们提出了一种基于堆叠智能超表面（SIM）的有前景的收发器架构。 SIM 是通过堆叠一系列可编程超表面层来构建的，其中每一层都由大量低成本的无源超原子组成，这些超原子可以单独操纵电磁 (EM) 波。通过适当配置无源元原子，SIM 能够完成高级计算和信号处理任务，例如多输入多输出 (MIMO) 预编码/组合、多用户干扰缓解和雷达感测，如 EM波通过超表面的多层传播，有效降低了与射频相关的能耗和处理延迟。受此启发，我们概述了 SIM 辅助 MIMO 收发器设计，其中包括其硬件架构及其相对于最先进解决方案的潜在优势。此外，我们还讨论了有前景的应用场景，并确定了与下一代无线网络的高级 SIM 架构设计相关的开放研究挑战。最后，提供了数值结果来量化无线系统中基于波的信号处理的优势。