Channel-Tolerant OFDM System for an Underwater Acoustic Channel

As is well known, the robust and reliable acoustic communication in adverse littoral water is a very challenging task. Orthogonal frequency division multiplexing (OFDM) is a promising technique for achieving high speed rate and combating multi-path fading in underwater acoustic communication. In this paper, the basic principle of OFDM system is firstly introduced. Then a channel estimation method based on pilot symbol assisted modulation (PSAM) is studied. Finally, the experiment results are presented to compare the channel estimation performance of three pilot patterns. It is concluded that the comb pilot pattern is not suitable for complex underwater acoustic channel.