Improved bandwidth performance of hybrid optical wireless communication for an indoor IoT environment

Abstract

In this paper, we propose the hybrid optical wireless communication system using a single light-emitting diode (LED) as a transmitter (Tx) as well as a photodiode and image sensor-based receivers (Rxs) for an indoor IoT environment. The proposed system utilizing a single LED offers simultaneously high- and low-speed transmission capabilities using visible light communication (VLC) and optical camera communication (OCC) links, respectively. The proposed scheme is intended to provide a versatile IoT environment by giving users the choice to switch between links based on device availability. By means of experimental implementation, we show that using a chip LED modulated with bipolar on-off keying modulation format and biased voltage levels improves signal transmission on both VLC and OCC links and thus the throughput of the system. Furthermore, we propose amplitude overlap ${A}_{\mathrm {OL}}$ in the modulation format to improve the data throughput of VLC link. The results depict that error-free transmission is achieved for the VLC link at a data rate of up to 100 Mb/s which is double the 3-dB bandwidth of LED at ${A}_{\mathrm {OL}}$ values of 0.3 and 0.5, and for the OCC link at a data rate of up to 2 kb/s at ${A}_{\mathrm {OL}}$ values of 0 and 0.3.