Empowering Programmable Wireless Environments with Optical Anchor-based Positioning

TL;DR

This work investigates integrating RIS-enabled PWEs with optical anchors to achieve ultra-precise localization necessary for exploiting large RIS configurations in 6G networks. It compares RIS-based and RIS-independent localization approaches, then proposes a PWE architecture with optical anchors and the LERIS concept, including an LATC scheme that uses RSS and AoA to enable precise UE positioning and codebook-driven RIS configuration. Preliminary results demonstrate that increasing the RIS element count improves beam directivity and reduces localization tolerance, while optical-anchor RSS achieves high accuracy under practical LoS conditions, supporting the feasibility of ultra-precise localization for advanced wavefront shaping. Overall, the paper highlights high-precision localization as a key enabler of RIS functionality in PWEs and motivates hybrid RF/optical strategies and AI-assisted localization for robust, scalable 6G deployments.

Abstract

The evolution toward sixth-generation (6G) wireless networks has introduced programmable wireless environments (PWEs) and reconfigurable intelligent surfaces (RISs) as transformative elements for achieving near-deterministic wireless communications. However, the enhanced capabilities of RISs within PWEs, especially as we move toward more complex electromagnetic functions by increasing the number of reflecting elements, underscore the need for high-precision user localization, since inaccurate localization could lead to erroneous configuration of RISs, which would then compromise the effectiveness of PWEs. In this direction, this paper investigates the integration of RISs and optical anchors within PWEs, emphasizing the crucial role of ultra-precise localization in unlocking advanced electromagnetic functionalities. Specifically, we present an in-depth analysis of various localization techniques, both RISbased and RIS-independent, while introducing the concept of empowering PWEs with optical anchors for enhanced localization precision. Our findings highlight that accurate localization is essential to fully exploit the capabilities of RISs, paving the way for future applications. Through this exploration, we contribute to the advancement of PWEs in line with the ambitious goals of the 6G standards and improve the quality of service in next generation wireless networks.

Figures (4)

• Figure 1: Overview of a PWE empowered with optical anchors
• Figure 2: Beam steering directivity versus number of reflecting elements
• Figure 3: Tolerated localization error $\sigma_p$ versus RIS-UE distance
• Figure 4: Localization error of optical anchor-based RSS method versus $K$