22. Impact of Imperfect CSI on the Performance of Inhomogeneous Underwater VLC System

The chapter delves into the performance analysis of an inhomogeneous underwater visible light communication (UWVLC) system, focusing on vertical links. It models the underwater channel as a cascaded structure of multiple layers, each with varying statistical characteristics. The impact of imperfect channel state information (CSI) is examined, revealing significant performance degradation, particularly with increasing depth. The chapter derives novel closed-form expressions for average symbol error probability (ASEP) for PAM and RQAM schemes, demonstrating the adverse effects of imperfect CSI on system performance. Numerical and simulation results validate the theoretical findings, showing that imperfect CSI leads to higher outage probabilities and required SNR for achieving target ASEP. The chapter's unique contribution lies in its comprehensive analysis of the impact of imperfect CSI on UWVLC systems, providing valuable insights for designing robust underwater communication systems.