We work with local industry and scientists to study the impact of propagation impairments on the acoustic communication link. We have developed our own acoustic testbed to transmit at a 27.5-kHz carrier to enable a 5-kHz bandwidth communication link for a range greater than one kilometer. The transceiver can support the deployment of a 3x5 Multiple-input Multiple-output (MIMO) communication link. This communication system has been deployed in Dalhousie’s Aquatron, in Halifax’s North West Arm and in Grand Passage, where the performance has been demonstrated in tidal flow. Our current efforts are focused on making a real-time receiver, and the algorithm is tested on Xilinx’s Zybo Z7 System-on-Chip.
To establish low-latency links and cross the air-water boundary, we are also studying the possibility of using magneto-inductive communications. This technique relies on near field coupling at low frequency to mitigate conductive losses in seawater. Analytical solutions have been validated with custom finite-difference time-domain simulation models, as well as with measurements in seawater tanks.