Multicarrier Systems Over Underwater Acoustic Channels: A Performance Evaluation

The use of clean communication paths underwater can enable important applications not only for the human being. Predictions of water-observation systems (e.g., oxygen levels, climate recording, pollutant contents) and monitoring/imaging animal activity (e.g., fish, micro-organisms) could anticipate actions to preserve underwater life in case of natural disturbances. Thus, a well-designed underwater communication system goes beyond military and commercial applications, it is an agent to safeguard ocean and rivers lives. This work contributes to an underwater link design at evaluating the performance of two emerging waveforms techniques (OFDM and GFDM) and the classic FSK over an underwater acoustic channel. Large scale fading effects, including multipath fading, Doppler spread, and geometric issues are addressed. In addition to the well-known ability to combat multipath in electromagnetic channels, OFDM and GFDM are chosen due to their efficient use of bandwidth and higher data rate compared to the current underwater FSK modems. We analyze the performance of those techniques, as well as their similarities and differences in terms of the Bit Error Rate and Bitrate, evidencing that there is a performance tradeoff to be taken into account when choosing the waveform of submarine systems.