## 2 Related Work
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Ref. No.** & **Objective** & **Technologies Used** & **Performance Metrics** & **Description** & **Main Limitations** \\ \hline
[2] & Survey and categorization of MIMO VLC techniques and future research directions. & MIMO VLC, machine learning & BER & Conducted a comprehensive survey of MIMO VLC techniques and discussed the application of machine learning in MIMO VLC systems. Identified future research directions. & Does not address the impact of ambient light interference & Does not address the impact of ambient light interference, which is discussed the application of machine learning in MIMO VLC systems. Identified future research directions. & Does not explore the use of MIMO technology or analyze different modulation schemes that could enhance performance under varying ambient light conditions. \\ \hline
[13] & Impact of ambient light on VLC systems. & FPGA and analog circuits for ambient light interference & BER & Investigated the impact of ambient light on VLC systems using an experimental setup with a hybrid structure (FPGA and analog circuits). & Does not explore the use of MIMO technology or analyze different modulation schemes that could enhance performance under varying ambient light conditions. \\ \hline
[14] & Effect of traffic density on SNR and BER in V2V-VLC systems. & V2V-VLC & SNR, BER & Examined the effect of vehicular traffic density on SNR and BER in V2V-VLC systems. & Does not consider ambient light interference or the effects of various modulation schemes under different traffic and lighting conditions. \\ \hline
[16] & Analysis of MIMO-VLC system performance considering distance, data data rate, and modulation techniques. & BERG, transmission system performance & Assessed MIMO-VLC system performance considering distance, data rate, and modulation techniques. & Does not consider ambient light interference or analyze the impact of different modulation schemes on modulation schemes on system resilience to such interference. \\ \hline
[17] & Comparison of NRZ-OOK and simulation, RZ-OOK, RZ-OOK performance in VLC systems. & Q-factor, BER & Studied the performance of indoor VLC systems using NRZ-OOK and RZ-OOK & Limited focus on NRZ-OOK and RZ-OOK without exploring modulation in OptiSystem, showing improved performance with NRZ-OOK. & NRELZ-OOK and RZ-OOK without exploring advanced modulation techniques. Does not investigate the use of MIMO systems. \\ \hline
[27] & Evaluation of VLC system performance using white LEDs at different data rates and link lengths. & NRZ-OOK & Q-factor, BER & Evaluated the performance of an indoor VLC system using white LEDs, measuring quality factor and BER at various data rates and link lengths. & Focuses only on NRZ-OOK modulation and lacks advanced interference mitigation techniques \\ \hline
[28] & Mitigation of ambient light interference in vehicular VLC systems. & Various suppression methods in electronic and optical domains & BERG & Investigated techniques to suppress ambient light interference across multiple domains, focusing on VLC systems for vehicular communication. & Does not analyze the effects of modulation schemes or MIMO techniques, and is limited to specific methods of interference suppression. \\ \hline
[29] & Vehicular VLC network architecture for I2V and V2V communication. & Tree-based network access scheme, VLC & Network coverage, connectivity & Proposed a vehicular VLC network architecture for I2V and V2V communication using a tree-based access scheme to connectivity. & Does not explore the effects of modulation schemes or MIMO techniques. \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary of related work. From the above discussion, it is evident that some studies on VLC systems focus on mitigating ambient light interference without incorporating MIMO techniques, while others explore MIMO techniques without addressing the impact of different modulation schemes or ambient light interference.