Millimeter-wave (mmWave) communication enables multi-gigabit-per-second data rates but is highly susceptible to path loss and blockage, especially indoors. Many indoor settings, however, include naturally occurring specular surfaces such as glass, glossy metal panels, and signage, that reflect both light and mmWave signals. Exploiting this dual reflectivity, we propose See and Beam, a low-cost framework that combines LiDAR sensing with passive specular reflectors to enhance mmWave connectivity under non-line-of-sight (NLoS) conditions. In this paper, as a proof of concept, we deploy three types of reflectors, glossy, smooth, and matte (non-specular), to evaluate joint LiDAR/mmWave reflection in an indoor scenario. We demonstrate that using LiDAR-mmWave co-reflective surfaces enables a co-located LiDAR sensor to map the NLoS environment, localize NLoS users, and identify viable communication reflection points. Experimental results at 60 GHz show that LiDAR-guided beam steering with co-reflective surfaces improves the minimum received signal strength by over 20 dB in deep NLoS regions. Moreover, LiDAR-derived angle-of-departure steering achieves performance comparable to exhaustive NLoS beam search. This low cost, and scalable framework serves as an effective alternative to configurable reflecting surfaces and enables robust mmWave connectivity in future 6G and beyond networks.

翻译：毫米波通信能够实现每秒数千兆比特的数据速率，但对路径损耗和遮挡极为敏感，尤其在室内环境中。然而，许多室内场景天然存在镜面反射表面，如玻璃、光滑金属板和标识牌，这些表面既能反射光线也能反射毫米波信号。基于这种双重反射特性，我们提出了See and Beam，一种低成本框架，通过结合激光雷达传感与被动镜面反射器来增强非视距条件下的毫米波连接性。本文作为概念验证，部署了三种类型的反射器（光滑、平滑和哑光非镜面），以评估室内场景中激光雷达与毫米波的联合反射性能。我们证明，利用激光雷达-毫米波共反射表面，可使共置的激光雷达传感器映射非视距环境、定位非视距用户并识别可行的通信反射点。在60 GHz频段的实验结果表明，采用激光雷达引导的波束赋形与共反射表面，在深度非视距区域将最小接收信号强度提升了超过20 dB。此外，基于激光雷达的出发角波束赋形实现了与穷举非视距波束搜索相当的性能。这一低成本、可扩展的框架为可配置反射表面提供了有效替代方案，并为未来6G及更高代际网络中的稳健毫米波连接性奠定了基础。