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A 120 Mbps WDM-based VLC system for implementation of Internet of Things

Abstract It is envisioned that by 2022, the number of Internet of Things (IoT) devices will be more than 20 billion. The transfer of information between IoT devices is heavily dependent on wireless links based on the radio frequency (RF) spectrum. Due to the scarcity of limited and licensed RF spectrum, visible light communication (VLC) based IoT links can be considered as a promising and viable solution. In this work, four channels are multiplexed to carry low-datarate information over a VLC link using cost-effective and easy to implement on-off-keying (OOK). Red, blue, green, and amber light-emitting diodes (LEDs) are deployed for parallel data transportation. The proposed system has been designed and simulated using Optisystem software. Through numerical simulations, we investigate the bit error rate (BER) performance of the proposed VLC link with increasing transmission range. Also, we investigate the BER performance of the proposed VLC link under the impact of increasing detection surface area, responsivity of the photodiode, and slope efficiency of the LEDs. Further, the performance of the proposed VLC link has been compared for different data transmission rates using non-return-to-zero and return-to-zero modulation schemes.