Adaptive visible light communication LED receiver

Abstract

We consider a visible light communication (VLC) system with light emitting diodes (LEDs), wherein LEDs are used for information transmission as well as reception while providing illumination. At the transmitter, a combination of a pulse width modulation (PWM) signal and a redundant run-length limited encoded on-off keying (OOK) signal is used for data transmission. The LED receiver uses OOK and the OFF periods therein for VLC reception. The range of such a system is however affected by ambient light changes and device portability. To address this problem, we propose a two-step decoder with edge detection followed by K-means clustering and adaptive threshold detection. We show that the proposed system achieves about 33% higher range in comparison to a non-adaptive VLC system.