  In this paper, we study a multi-user visible light communication (VLC) system
assisted with optical reflecting intelligent surface (ORIS). Joint precoding
and alignment matrices are designed to maximize the average
signal-to-interference plus noise ratio (SINR) criteria. Considering the
constraints of the constant mean transmission power of LEDs and the power
associated with all users, an optimization problem is proposed. To solve this
problem, we utilize an alternating optimization algorithm to optimize the
precoding and alignment matrices. The simulation results demonstrate that the
resultant SINR of the proposed method outperforms ZF and MMSE precoding
algorithms.
