Date Added: Mar 2010
UnderWater Acoustic (UWA) channels are doubly selective channels, having large delay spread and significant Doppler effects. Channel estimation, which is one critical task in the receiver design, is extremely challenging in the UWA communication context due to the large number of unknowns as a result of large delay and Doppler spread. Exploiting the sparse nature of UWA channels has been recently shown to be highly effective, based on experimental results for both single-carrier and multi-carrier, underwater transmissions. Orthogonal Matching Pursuit (OMP) and other Matching Pursuit (MP) variants have been tested, while a Basis Pursuit (BP) algorithm is also tested.