An Integrated Illumination LED Driver and Optical Wireless Communications Repeater

Abstract

Visible light communications (VLC) leverages optical bands to meet the escalating demands for wireless communication. This paper presents a new approach to address the challenges encountered in establishing an optical uplink and downlink relay for VLC systems. A multi-phase boost converter topology is developed to realize a repeater capable of receiving and amplifying infrared uplink signals and re-transmitting them across both infrared and visible spectra. Conventional commutating diodes within each phase of the converter are replaced with photodiodes, enabling the detection of infrared (IR) signals. The resultant photocurrent modulates the intensity of multiple emitters at output, enabling spatial summation and amplification of the re-transmitted signal. While the primary application is to establish an optical IR uplink to visible light broadcast system, the topology can also support alternative applications, such as optical backhauling/fronthauling by integrating IR emitters into the luminaire. Simulation and experimental results indicate that the integration of the repeater into a luminaire through this approach does not adversely impact the efficacy of the luminaire and for the tested configurations the repeater is capable of an end-to-end optical gain of 7 for IR signals with amplitudes of $1-10~\mathrm {mW}$ .