An Adaptive Acoustic Transceiver Testbed on System-on-Chip for Underwater Communication

This paper describes a test setup to support the development of a bi-directional acoustic communication link relying on adaptive transceivers. The physical layer relies on the JANUS protocol for discovery of new nodes and assessment of the channel conditions. The transmitter has a bandwidth of 5 kHz at a center frequency of 27.5 kHz, while the receiver relies on broadband hydrophones. The embedded system allows to transmit in diverse underwater scenarios, and the System-on-Chip is programmed to transmit various waveforms including through coded Orthogonal Frequency Division Multiplexing (OFDM). Key elements of the program are described to maintain real-time operation on the embedded systems. At the receiver, the data is sampled at 96 kHz and a 4 Mbps cabled link to a host interface is developed to diagnose the communication link reliability.