CMOS-based single-channel circuit prototype for bidirectional transmission via visible light for LiFiX

LiFiX is the concept of a fully bi-directional integrated LiFi system featuring up to 64 emitter-receiver cells in an array meant to reach 26 Gb/s of bandwidth guarded by a high level of data-transmission security via frequency hopping using visible and IR wavelengths. This paper presents CMOS integrated transmitter/receiver modules (Tx/Rx), adjusted to transmit and receive information remotely via modulated LED light, where each module has a CMOS chip equipped with post-assembled microLED for light transmission and an integrated receiver module. We have designed and characterized a 0.35-μm AMS CMOS chip with several arrays of multiplexed pixels, which was adapted to set up a Tx/Rx uni-directional communication channel. This work presents a first demonstrator of LiFiX capability on chip, to enable the identification of issues that will further guide us through a future design of a custom chip, with tailored LED driving circuits, multiplexing scheme and light detection, according to the LiFiX specs.