Increasing the Data Rate for Reflected Optical Camera Communication Using Uniform LED Light

Abstract

Optical Camera Communication (OCC) systems relying on commercial-off-the-shelf (COTS) devices have attracted substantial attention recently, thanks to the pervasive deployment of indoor LED lighting infrastructure and the popularity of smartphones. However, the achievable throughput by such practical systems is still very low due to its availability for only low order modulation schemes and transmission frequency. In this demo, we propose a novel reflected OCC system, UniLight, which takes advantage of uniform light emission of an LED luminaire with lens to increase both region of interest (RoI) and signal-to-noise ratio (SNR) so as to improve data rate. UniLight employs a COTS LED spotlight with lens as the transmitter to uniformly illuminate a reflector so that avoids a gradual reduction of brightness from the center to both sides in the frame captured by a camera receiver. By adopting a hybrid modulation scheme for generating multi-level pulse amplitude modulation (M-PAM) symbols on the transmitter and a machine learning based demodulator on the smartphone receiver, UniLight can achieve much higher data rate than existing works with a single small-size LED spotlight.