Leakage-based precoding for MU-MIMO VLC systems under optical power constraint

In this paper, we investigate a multiuser multiple-input multiple-output (MU-MIMO) system for indoor visible light communication (VLC), in which precoding is conducted under optical power constraint rather than electrical power constraint. Leakage-based precoding designed by maximizing signal-to-leakage-plus-noise ratio (SLNR) is adopted to suppress the multiuser interference under optical power constraint and power allocation is proposed to maximize the throughput of the system. Simulations demonstrate the performance gain of optimal power allocation and indicate that the leakage-based precoding scheme outperforms zero forcing counterpart when the channel is highly correlated and still works well when the number of transmitters is less than that of receivers.