Multiuser MIMO for Underwater Visible Light Communication

Underwater visible light communication (UVLC) is a newly emerging technique in the field of wireless communication. Numerous studies indicated that it can achieve high data rate (on the order of Gbps) over tens of meters of communication link. Multiuser multiple-input multiple-output (MU-MIMO) systems have a potential to provide high capacity, interference suppression and space division multiple access. In this paper the performance of an orthogonal frequency division multiplexing (OFDM)-based MU-MIMO system for underwater visible light communication (VLC) is investigated. It is worth to note that MU-MIMO OFDM has been applied for indoor optical communication, however, to the best of our knowledge, it has not been studied for underwater environment yet. The system is considered to be 2×2 and the channel gain for each path is calculated with the closed-form expression for weighted double gamma function (WDGF). Zero-forcing precoding scheme is implemented to eliminate multiuser interference.