Prototyping and real-world field trials of RIS-aided wireless communications

TL;DR

This paper presents the design, fabrication, and real-world testing of RIS systems for 5G networks, demonstrating significant power gains in various environments and proposing an efficient beamforming algorithm based on spatial channel structure.

Contribution

It introduces a practical RIS prototype, a low-complexity beamforming algorithm, and validates RIS effectiveness through extensive field trials in diverse settings.

Findings

10-20 dB power gain in office and corridor environments at 5.8 GHz

Over 35 dB power gain in outdoor tests with RIS

4-7 dB indoor signal improvement in 5G networks

Abstract

Reconfigurable intelligent surface (RIS) is a promising technology that has the potential to change the way we interact with the wireless propagating environment. In this paper, we design and fabricate an RIS system that can be used in the fifth generation (5G) mobile communication networks. We also propose a practical two-step spatial-oversampling codebook algorithm for the beamforming of RIS, which is based on the spatial structure of the wireless channel. This algorithm has much lower complexity compared to the two-dimensional full-space searching-based codebook, yet with only negligible performance loss. Then, a series of experiments are conducted with the fabricated RIS systems, covering the office, corridor, and outdoor environments, in order to verified the effectiveness of RIS in both laboratory and current 5G commercial networks. In the office and corridor scenarios, the 5.8 GHz RIS provided a 10-20 dB power gain at the receiver. In the outdoor test, over 35 dB power gain was observed with RIS compared to the non-deployment case. However, in commercial 5G networks, the 2.6 GHz RIS improved indoor signal strength by only 4-7 dB. The experimental results indicate that RIS achieves higher power gain when transceivers are equipped with directional antennas instead of omni-directional antennas.