Performance analysis of NOMA system with imperfect SIC-based infrastructure-to-vehicle visible light communication

The Non-Orthogonal Multiple Access (NOMA) scheme is a well-known technique used to improve the performance of Visible Light Communication (VLC) networks, specifically in the context of Vehicular VLC (V-VLC) for Infrastructure-to-Vehicle (I2V) communication. In this study we aim to assess the performance of NOMA systems integrated with the Infrastructure-to-Vehicle (I2V) VLC, considering the realistic scenario of imperfect Successive Interference Cancellation (SIC) for signal decoding. The study employs a comprehensive system model that incorporates multiple vehicles and a single infrastructure equipped with VLC transmitters and it incorporates realistic channel modeling for I2V communication. The NOMA scheme is implemented by using the power domain multiple access technique, where two vehicles are served concurrently by superposing their signals. Imperfect SIC is considered to account for the decoding errors occurring at the vehicles’ receivers due to residual interference. To evaluate the system’s performance, key performance metrics such as theoretical achievable capacity, bit error rate and fairness index are analyzed. The optimal power allocation coefficient that maximizes the total capacity and the fairness index is then obtained after formulating the optimization problem. Simulation results demonstrate that imperfect SIC has a noticeable impact on system performance, the total achievable data rate decreases by 5.7% when the fraction of the residue signal equals 0.05. This highlighting the necessity for efficient interference management techniques in this context.