Robust Underwater Acoustic Communication Algorithm for a Moving Vehicle Based on Adaptive Time-Reversal Processing

摘要

Recently, multiple focusing with adaptive time-reversal mirror (ATRM) was introduced to the simultaneous focusing in the frequency domain, as well as to pulse compression at the multiple locations in highly dispersive and reverberating channel [J. S. Kim and K. C. Shin, J. Acoust. Soc. Am., 115, 600-606 (2004)]. In this study, ATRM is extended to the broadening of focal size in the frequency domain in an ocean waveguide. The broadening of focal size in range direction is achieved by imposing a set of constraints, also known as multiple constraint method (MCM). The signal vectors used in the constraints are found from the theory on waveguide invariant for each frequency. The final time domain solutions, or the bit sequences to be transmitted from transmit/receive array, are found from inverse Fourier transformation. The developed algorithm can find many applications where the robust and broader focal size is desired. In this paper, the algorithm is demonstrated in the context of the underwater acoustic communication from transmit/receive array to the moving remotely-operated vehicle (ROV) with considerable speed.