Towards A Practical Multicarrier Modem for Underwater Telemetry and Distributed Networks

The success of multicarrier modulation in the form of orthogonal-frequency-division-modulation (OFDM) in radio channels illuminates a clear path one could take towards high-rate underwater acoustic communications. However, earlier work on the application of OFDM in underwater has only had limited success. We aim to make OFDM work for underwater acoustic channels and build a practical multicarrier modem prototype. We have worked on four different aspects of this problem. • Modulation: Make OFDM work underwater. • Channel coding: Drastically improve the system performance. • Detection and synchronization: Pave the way towards online receivers. • Prototype development: Put our algorithms into practice. Our progress is summarized as follows