A Two-Dimensional Constellation Design Method for Visible Light Communications With Signal-Dependent Shot Noise

In this letter, we propose an effective constellation design method for visible light communication with signal-dependent shot noise (SDSN) in a two-dimensional (2-D) signal space. Two orthonormal basis functions are selected to construct the largest signal space. As the transmitted signals are distorted by SDSN, the improved constellation is obtained through minimizing the maximal symbol error rate among all constellation point pairs under some practical constraints. Simulation results show that the proposed 2-D constellation optimization method significantly outperforms the one applied in the 1-D signal space.