BER Analysis for NOMA-Enabled Visible Light Communication Systems with M-PSK

Visible light communication (VLC) and non-orthogonal multiple access (NOMA) are deemed two promising technologies in the next generation wireless communication systems due to their capabilities in achieving high capacity and massive connectivity. This paper studies the performance of a NOMA-enabled VLC system using M-ary phase shift keying (M-PSK). In particular system level bit error rate (BER) are derived for different modulation orders. Conventional methods used for analyzing the BER under orthogonal multiple access cannot be directly applied to NOMA. We propose an analytical framework based on bitwise-decision axis and signal space to obtain the closed-form BER expressions for a NOMA-enabled VLC system using M-PSK. Simulation results demonstrate the accuracy of the theoretical analysis. The study shows that the BER gap among users decreases with the increase of the modulation order but at the cost of a higher power consumption in order to achieve a better signal to noise ratio. It is observed that 8-PSK modulation in NOMA-enabled VLC systems strikes a good tradeoff between the power cost and the achievable BER.