Precoded visible light communications

Multiple input multiple output (MIMO) technology appears attractive for indoor visible light communication (VLC) systems as multiple light-emitting diodes (LED) sources are typically deployed for indoor environment. Most of current indoor MIMO VLC systems utilize single user terminal scenario to investigate the performance of the system. However, typical arrangement of a practical indoor environment is comprised of multiple user terminals, which makes it complicated for signal processing. However, reduction of the complexity of a mobile terminal is advantageous to its signal processing capability and battery life extension. This paper investigated the precoded multi-user (MU) MIMO indoor VLC system. Since the main difficulty of MU-MIMO VLC system is to distinguish the received data for decentralized user terminals, precoding method is introduced to eliminate multi-user interference (MUI) in the transmitter of a VLC system, which leads to the reduction of complexity and power consumption of user terminals. Based on a 4 × {2, 2} indoor VLC system at 100 Mbit/s, the proposed system can perform well through numerical simulations.