We study the received signal strength indicator (RSSI)-based ranging performance of a cellular user in a millimeter-wave (mm-wave) network aided by reconfigurable intelligent surfaces (RISs). First, we propose an optimal RIS deployment strategy that minimizes the joint blockage probability of the user to the base station (BS) link and the user to the RIS link. Then, we provide a bound-based characterization of a ranging strategy in which the BS estimates the distance the user in the direct link in case it is in the line of sight (LOS) state, whereas in case the direct link is blocked, the BS estimates the user distance via the reflected, i.e., RIS-aided link. In literature, for maximizing the path-gain the RIS deployment is recommended to be in close proximity to the BS. In contrast, our study shows that in the presence of blockages, close locations of the RIS and the BS is sub-optimal.

中文翻译：

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在毫米波网络中放置基于 RSSI 的测距的智能表面

我们研究了蜂窝用户在可重构智能表面 (RIS) 辅助下的毫米波 (mm-wave) 网络中基于接收信号强度指标 (RSSI) 的测距性能。首先，我们提出了一种最优RIS部署策略，最小化用户对基站（BS）链路和用户对RIS链路的联合阻塞概率。然后，我们提供了一种基于边界的测距策略表征，其中 BS 估计用户在直接链路中的距离，以防它处于视线 (LOS) 状态，而在直接链路被阻塞的情况下， BS 通过反射的，即 RIS 辅助的链路估计用户距离。在文献中，为了最大化路径增益，建议 RIS 部署靠近 BS。相比之下，我们的研究表明，在存在堵塞的情况下，