Characteristics of SINR and Ergodic Capacity for MIMO-Based Vehicular VLC

In response to the shortcomings existing in radio frequency vehicular communications, vehicular visible light communication (VVLC) provides a viable alternative. However, the fluctuation of optical intensity induced by atmospheric turbulence (AT) adversely affects the communication performance of VVLC. In this letter, multi-input multi-output (MIMO) VVLC is employed to enhance communication performance by leveraging diversity. Since the probability distribution of signal-to-interference-plus-noise ratio (SINR) for MIMO-based VVLC is difficult to formulate, a weighted two-step approximation (WTA) method is proposed to approximate it with a log-normal distribution. Subsequently, the ergodic capacity is calculated by the Gauss-Hermite quadrature. Simulation results show that the log-normal distribution obtained by the proposed WTA method effectively approaches the SINR distribution, thus ensuring the accuracy of the ergodic capacity.