Quadrichromatic LED based mobile phone camera visible light communication

Abstract

A quadrichromatic light-emitting diode (QLED) based visible light communication for mobile phone camera is proposed to improve data rate and enhance illumination effect at the same time. Different from color intensity modulation (CIM), we propose and use color ratio modulation (CRM) in CMOS image sensor based visible light communication to improve data rate. According to the spectral power distribution (SPD) of the QLED and the spectral response of the complementary-metal-oxide-semiconductor (CMOS) image sensor, color multiple-input multiple-output (CMIMO) channel model is set up first to obtain optimal 16-CRM constellation design. Taking full consideration of the high quality of color rendering index (CRI), tunable color temperature (CT), we design a specific data packet structure to realize illumination requirements. A decoding strategy is also addressed for demapping at the receiver. The experimental results demonstrate that the proposed scheme can realize a downlink data rate of 13.2kbit/s, meanwhile, the optical signal source is illumination compatible.