Broadband synchronization of underwater acoustic communication signals using superimposed pilots

A low-complex methodology to synchronize broadband underwater acoustic channels is proposed. The aim of the scheme is to process the received signal in such a way that the highly time-varying discrete-time channel turns time-invariant. Suggested is an LMS-like strategy based on superimposed pilots. Simulations on realistic models show that the proposed scheme is able to maintain very stable channel properties throughout long data frames. This indicates that the derived strategy is a highly attractive component for various underwater communication applications as channel variation is often the limiting factor in system performance.