OFDMA communication system for cooperative localization of underwater vehicles

Cooperative localization systems require some kind of communication between the different members of the network. In underwater environments this communication is not trivial, since it is based on acoustic signals that propagate in a challenging environment characterized by multipath, Doppler effect and long delays. To avoid collisions between the different members of the network, usually a Time-Division Multiple Access (TDMA) scheme is employed, which cause a high latency in the system. In this work, a communication system based on Orthogonal Frequency-Division Multiple Access (OFDMA) is presented. This system can be used by a team of Autonomous Underwater Vehicles (AUVs) to exchange information in order to perform cooperative localization with no time scheduling, minimizing the system latency. Experimental tests showed the feasibility of the communication system, retrieving the original data even when the signals overlap at the receiver.