Underwater Acoustic Communication in a Highly Refractive Environment Using SC–FDE

Single-carrier frequency-domain equalization (SC-FDE) is a promising technique for coherent underwater acoustic communications. The method has a lower peak-to-average power ratio than orthogonal frequency-division multiplexing (OFDM) and is more resistant to frequency offset. In this work, SC-FDE performance is evaluated using data collected during the 2009 Cooperative Array Performance Experiment (CAPEx09) that took place near Seattle, WA, USA. CAPEx09 had two densely populated vertical receiving arrays and a highly refractive environment, features that make it suitable for examining issues related to sensor positioning in range and depth. Two-channel equalization results show only a weak dependence on the spacing between the two sensors. Communications performance is interpreted in terms of relevant propagation physics, including acoustic ducting and rough surface scattering. The implications for undersea acoustic networks are discussed.