Abstract: Underwater acoustic channel is the most complex channel in all of the communication channels.Strong modulation and coding mode must be applied in such system.A LDPC coded OFDM system scheme for underwater acoustic channel is proposed.The authors adopt LDPC codes to correct the errors and eliminate the interference carrier interruption with an equalizer further.Simulation results validate its good performance.

Key words: underwater acoustic channel, low density parity check code, orthogonal frequency division multiplexing, equalizer