Li2BC: From Visible Light Communication to Ambient RF Backscatter

Ambient backscatter communication (AmBC) is a key enabler for the energy-efficient Internet of Things (IoT) that employs existing radio frequency (RF) signals for low-power communication. One open question is how to efficiently send data to the backscatter device (BD) for controlling its operations. Recent research reveals that the ubiquitous presence of configurable light-emitting diodes (LEDs) can leverage such control functionalities by involving visible light communication (VLC). However, existing works only consider relaying the received VLC signals for BD control without storage and processing, which sacrifices configurability and flexibility. In this paper, we propose the Li2BC, a backscatter device (BD) that integrates the VLC receiving, processing, and backscatter modulation functionality. By leveraging a low-power microcontroller, the BD can receive, amplify, demodulate, and store/cache VLC signals. The stored/cached signals are then used for backscatter control. We demonstrate the end-to-end data transmission from LEDs to an RF receiver. The investigations verify that the Li2BC can efficiently receive VLC signals and then use them to control backscatter modulation.