Proposing a method for attaining high data transmission rate in long-range underwater acoustic communication

We aim to present a better method for long range communication in UWA (underwater acoustic) channel that is multi-path, time-varying and frequency-dispersive. Based on the oceanic experiments in 80 km range communication and the theoretical study of MC (multi carrier) and MPSK (multi phase shift keying) modulations, a novel method of MC-MPSK modulation is presented in this paper. In the full paper, we explain the better method in much detail. In it we successively discuss four points; (1) the model of UWA communication channel; (2) the method of MC-MPSK modulation and demodulation combines the MFSK (multi frequency shift keying) with MPSK; the carrier of MPSK is the frequency information of MFSK; the information is transmitted by both frequencies and phases of signals; (3) the comb equalizer for MC-MPSK in the fading UWA communication channel; (4) the simulation results of the comb equalizer and the MC-MPSK; one result particularly worth noticing is that the SNR (signal to noise ratio) can be less than -10 dB when the BER (bit error rate) is 10^-4. The simulation results indicate that MC-MPSK is useful in long-range underwater acoustic communication.