Reconfigurable Intelligent Surface -Assisted Ambient Backscatter Communications -- Experimental Assessment

TL;DR

This paper experimentally demonstrates that reconfigurable intelligent surfaces can significantly enhance ambient backscatter communication by directing reflected waves to improve signal strength and reduce interference, enabling more efficient 6G passive communication systems.

Contribution

It introduces a novel RIS-assisted ambient backscatter system with controlled reflection, improving communication performance through experimental validation.

Findings

Enhanced signal strength at tag and reader locations

Significant performance improvement in ambient backscatter communication

Effective control of reflected waves using a predefined codebook

Abstract

Sixth generation (6G) mobile networks may include new passive technologies, such as ambient backscatter communication or the use of reconfigurable intelligent surfaces, to avoid the emission of waves and the corresponding energy consumption. On the one hand, a reconfigurable intelligent surface improves the network performance by adding electronically controlled reflected paths in the radio propagation channel. On the other hand, in an ambient backscatter system, a device, named tag, communicates towards a reader by backscattering the waves of an ambient source (such as a TV tower). However, the tag's backscattered signal is weak and strongly interfered by the direct signal from the ambient source. In this paper, we propose a new reconfigurable intelligent surface assisted ambient backscatter system. The proposed surface allows to control the reflection of an incident wave coming from the exact source location towards the tag and reader locations (creating hot spots at their locations), thanks to passive reflected beams from a predefined codebook. A common phase-shift can also be applied to the beam. Thanks to these features, we demonstrate experimentally that the performance of ambient backscatter communications can be significantly improved.