An Optimal Power Allocation for Multi-LED Phase-Shifted-Based MISO VLC Systems

Multi-LED phase-shifted superposition transmission technique has been proposed as a means to increase the rate of visible light communication (VLC) system. We present an optimal power allocation scheme for multi-LED phase-shifted pulse amplitude modulation (PAM) based multi-input single-output indoor VLC systems. An optimal design criterion with the maximum likelihood detection is described, and meanwhile, a closed-form allocation solution is developed with non-vanishing minimum Euclidean distances as the constellation size increases. The simulation results indicate that the proposed power allocation strategy obtains significant performance gains over the uniform power allocation system.