Study on channel estimation technique of OFDM underwater acoustic communication system

The underwater acoustic channel is very complex where cochannel interference, doppler frequency offsets, narrow bandwidth, serious multi-path time delay interference and frequency selective deep fades obstruct the development of high speed and fidelity underwater data transmissions. Orthogonal frequency division multiplexing (OFDM) is a kind of novel parallel transmission technology. The principle of OFDM is that the whole bandwidth can be divided into some orthogonal sub-channels; the high-speed serial signal stream is modulated by some orthogonal sub-carriers. In this paper, we mainly discuss three different pilot structures on channel estimation in OFDM underwater acoustic communication system and analyze the performance of channel estimation based on different pilot structures by simulation.