Line-of-sight VLC in inhomogeneous underwater medium: Performance evaluation

In this work, an underwater visible light communication vertical link is evaluated considering the inhomogeneity in underwater environment. The link is formed between an underwater transmitter (Tx) and a receiver (Rx) which is placed over a mount at the sea-level or above. Link budget formulas for the received power () are deduced. A numerical example is given to illustrate the BER performance under different link conditions. The effects of different system parameters such as average transmitted power (), data rate () and Tx orientation angle () on the BER performance are studied. When increases ten times, the maximum angular Rx position () increases by 8%-14% for the same data rate. It is shown that maximum received power is obtained when the Tx is pointed upwards facing the sea-level. Moreover, the effect of Rx altitude from the sea-level is studied for different weather conditions. The provided results indicate that under heavy and moderate fog, the Rx is best located at the sea-level. Whereas under light foggy weather, two cases exist. If the average transmitted power is relatively low, the Rx is to be mounted above sea-level for better performance. However, if it is relatively high, the Rx is better placed at the sea-level.