Time reversal MFSK acoustic communication in underwater channel with large multipath spread

• Published in: Ocean engineering Vol. 152; pp. 203 - 209
• Main Authors: Cao, Xiu-ling, Jiang, Wei-hua, Tong, F.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.03.2018
• Subjects: Down-conversion; ISI; MFSK; Multipath; Time reversal; Multipath; MFSK; Down-conversion; ISI; Time reversal
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2018.01.035

It has been recognized that, compared with coherent acoustic communication, Multiple Frequency Shift Keying (MFSK) underwater acoustic communication offers the advantages of low complexity, easy-implementation and channel tolerance, but it is subject to significant performance degradation caused by inter-symbol interference (ISI) when the multipath spread is larger than symbol duration. The time reversal is capable of effectively suppressing the channel multipath by the means of temporal-spatial focusing, which has been widely examined and applied in coherent underwater acoustic communication systems. However, there is a lack of investigations to incorporate the time reversal with MFSK communication. In this paper, we report a multi-channel time reversal MFSK receiver, in which the channel estimate is initially obtained and periodically updated by matched filtering of the sync preamble, meanwhile, down-conversion is adopted to reduce computational complexity. The performance of the proposed receiver is evaluated in a shallow water channel with severe multipath spread, in terms of bit error rate (BER) and robustness upon time variations. •This manuscript reports a time reversal MFSK receiver for underwater acoustic channel with large multipath spread.•Experimental results in shallow water channel with large multipath spread are provided to verify the tolerance of the proposed time reversal MFSK receiver to the time variations compared with that of the coherent time reversal receiver.•It verifies that the time reversal MFSK receiver is capable of mitigating the Doppler.