标题： 基于超表面的极大规模天线系统：收发器架构、物理建模和信道估计 显示英文标题

标题： Metasurface-Enabled Extremely Large-Scale Antenna Systems: Transceiver Architecture, Physical Modeling, and Channel Estimation

摘要： 超大规模天线阵列（ELAAs）已成为解决下一代无线通信系统前所未有的性能需求的关键技术。 为了提高其实用性，我们提出了基于超表面的超大规模天线（MELA）系统——一种新颖的收发器架构，该架构采用可重构的透射超表面来实现高效的空中射频到天线耦合和相位控制。 这种架构消除了传统解决方案中通常所需的大型开关矩阵和昂贵的移相器网络。 建立了物理基础模型，以表征电磁场通过单个透射单元单元的传播，捕捉波变换和传输的基本物理特性。 此外，引入了与距离相关的近似模型，表现出有利于高效参数估计和信号处理的结构特性。 基于信道模型，为包含混合近场和远场用户的场景提出了一种两阶段信道估计框架。 在第一阶段，一种字典驱动的波束空间滤波技术实现了快速的角度域扫描。 在精炼阶段，利用子阵列的旋转对称性设计超分辨率估计器，联合恢复角度和范围参数。 推导了MELA半功率波束宽度的解析表达式，揭示了其相对于传统ELAA架构的接近最优的空间分辨率。 数值实验进一步验证了所提出的信道估计算法的高分辨率和电磁模型的保真度，将MELA架构定位为一种高度有竞争力且具有前景的实用ELAA部署方案。 显示英文摘要

摘要： Extremely large-scale antenna arrays (ELAAs) have emerged as a pivotal technology for addressing the unprecedented performance demands of next-generation wireless communication systems. To enhance their practicality, we propose metasurface-enabled extremely large-scale antenna (MELA) systems -- novel transceiver architectures that employ reconfigurable transmissive metasurfaces to facilitate efficient over-the-air RF-to-antenna coupling and phase control. This architecture eliminates the need for bulky switch matrices and costly phase-shifter networks typically required in conventional solutions. Physically grounded models are developed to characterize electromagnetic field propagation through individual transmissive unit cells, capturing the fundamental physics of wave transformation and transmission. Additionally, distance-dependent approximate models are introduced, exhibiting structural properties conducive to efficient parameter estimation and signal processing. Based on the channel model, a two stage channel estimation framework is proposed for the scenarios comprising users in the hybrid near- and far-fields. In the first stage, a dictionary-driven beamspace filtering technique enables rapid angular-domain scanning. In the refinement stage, the rotational symmetry of subarrays is exploited to design super-resolution estimators that jointly recover angular and range parameters. An analytical expression for the half-power beamwidth of MELA is derived, revealing its near-optimal spatial resolution relative to conventional ELAA architectures. Numerical experiments further validate the high-resolution of the proposed channel estimation algorithm and the fidelity of the electromagnetic model, positioning the MELA architecture as a highly competitive and forward-looking solution for practical ELAA deployment.