Dual-repetitive pilot aided parameter estimation for underwater orthogonal frequency division multiplexing acoustic communications in the presence of strong composite noise

In this work, a novel design of signaling parameters and pilot placement is proposed for supporting robust underwater orthogonal frequency division multiplexing acoustic communications in the presence of strong composite noise. The proposed design allows for high-resolution estimation of various channel parameters that are essential to successful symbol recovery. Receiver processing algorithms are developed by exploring special properties of the received signal that hold valid despite complicated channel and noise effects. These algorithms are efficient since they reuse the same set of pilot symbols for multiple tasks of estimation that often require separate sets of pilots. They are also extremely effective because they largely avoid the effects of noise even when the noise is composite. The performance of these algorithms is evaluated via both extensive simulations and an at-sea experiment.