Real-Time MEMS-assisted Beam Steering for Visible Light Communication System

This paper presents a proof-of-concept of a luminaire-free visible light communications (VLC) link with real-time tracking based on a single micro-electro-mechanical systems (MEMS) mirror. The optical signal is applied to a polymer optical fiber (POF) and the collimated light is launched to the free space channel. The experimental setup includes a camera-based motion detection system and a MEMS mirror. The detection of the object is accomplished through the implementation of a background subtraction algorithm that utilizes Gaussian mixture models, followed by blob analysis and the application of geometrical transformations. Besides, the proposed system offers immunity against the receiver movement since it utilizes a single MEMS mirror to redirect the beam light and maintain a line-of-sight between the transmitter and receiver. The system is evaluated based on the bit error rate (BER) performance for different modulation bandwidths and detector gains. The results demonstrate the capability of the system to achieve speeds up to 10 Mbps using a non-return-to-zero on-off keying (NRZ-OOK) modulation format.