OFDM Pilot-Aided Underwater Acoustic Channel Estimation

Underwater Acoustic (UWA) communications have been regarded as the most challenging wireless communication systems due to their unique channel properties, such as severe multipath delay and large Doppler Shift. Orthogonal Frequency Division Multiplexing (OFDM) is a promising technique has been widely adopted in the 4G wireless communication systems due to its unique merits, such as robust against multipath propagation. However, the literature on OFDM communications in UWA environments is scarce. In this paper, we investigate OFDM pilot-aided UWA channel estimation approaches, which involve in block-type pilot, comb-type pilot and grid-type pilot. Therein, comb-type pilot-aided channel estimation approach will combine some signal interpolation approaches. Simulation results will show the performance difference of UWA communication systems based on difference channel estimation pilots.