Experimental studies of time-reversal underwater acoustic communications

Underwater acoustic communication is a key research topic in 3D ocean environmental monitoring network. This paper presents the results of an active/passive time-reversal communication experiment conducted in a waveguide tank. The results show that, in the presence of multi-path propagation, time-reversal processing achieves quite good focalization both spatially and temporally of the transmitted signal, thus efficiently mitigating inter-symbol interferences and inter-user interferences. Combining time-reversal with adaptive equalization can attain a communication performance similar to that of other popular methods, while the implementation complexity can be significantly reduced; it can also be readily implemented in a multi-user communication framework. The experimental results provide further evidences that the time-reversal technique can be a quite promising option for realizing high-speed, highly reliable data communication and multi-user communication in a complex underwater acoustic channel.