Wideband Underwater Wireless Optical Communication Based on Multi-Carrier Autoencoder

Underwater wireless optical communication (UWOC) has attracted considerable attention as a technology with high data rates and low time delays. However, the light scattering in water spreads beam pulse temporally, thereby resulting in time-varying underwater optical channels with inter-symbol interference (ISI) especially when the data rate is very high. To overcome this problem, in this letter, a multi-carrier autoencoder (AE) is proposed to incorporate the direct current optical orthogonal frequency-division multiplexing (DCO-OFDM) scheme into the AE network. In this way, proper constellation mapping and demapping schemes can be learned to cooperate with the DCO-OFDM modulation and the DC bias can be adaptively adjusted, efficiently dealing with the time-varying diffuse channel. The simulation results indicate that the proposed multi-carrier AE can achieve superior performance compared with other state-of-the-art techniques.