RIS-Aided Wireless Communications: Prototyping, Adaptive Beamforming, and Indoor/Outdoor Field Trials

TL;DR

This paper presents a practical RIS prototype with 1100 elements, demonstrating significant indoor and outdoor power gains, effective adaptive beamforming, and real-world data transmission over 500 meters, proving RIS's potential for future wireless systems.

Contribution

It introduces a new RIS prototype with an efficient over-the-air configuration algorithm and validates its performance through indoor and outdoor field trials with real data streaming.

Findings

26 dB power gain indoors with concrete wall obstacle

27 dB outdoor power gain in short-distance tests

Successful 32 Mbps data transmission over 500 meters

Abstract

The prospects of using a Reconfigurable Intelligent Surface (RIS) to aid wireless communication systems have recently received much attention from academia and industry. Most papers make theoretical studies based on elementary models, while the prototyping of RIS-aided wireless communication and real-world field trials are scarce. In this paper, we describe a new RIS prototype consisting of 1100 controllable elements working at 5.8 GHz band. We propose an efficient algorithm for configuring the RIS over the air by exploiting the geometrical array properties and a practical receiver-RIS feedback link. In our indoor test, where the transmitter and receiver are separated by a 30 cm thick concrete wall, our RIS prototype provides a 26 dB power gain compared to the baseline case where the RIS is replaced by a copper plate. A 27 dB power gain was observed in the short-distance outdoor measurement. We also carried out long-distance measurements and successfully transmitted a 32 Mbps data stream over 500 m. A 1080p video was live-streamed and it only played smoothly when the RIS was utilized. The power consumption of the RIS is around 1 W. Our paper is vivid proof that the RIS is a very promising technology for future wireless communications.