On study and analysis of the impact of the time reversal mirror on characteristics of the underwater acoustic channel

Abstract

Characterizing the UWA channel is critical for designing a robust communication receiver. Due to the signif-icant delay spread, underwater channels make communication difficult. The time-reversal mirror improves the channel char-acteristics by reducing delay spread and increasing coherence bandwidth. This paper analyses and quantifies a time reversal mirror (TRM) effect on an underwater acoustic channel. The delay spread decreases as the number of receivers increases, but this decrease is asymptotic, meaning that regardless of the receiver geometry, the delay spread converges to a fixed non-zero value. Additionally, this analysis establishes that the TRM effectiveness is dependent on the water column depth and the distance between the transmitter and receiver. As the number of receivers increases, the effectiveness of TRM approaches the same value regardless of the water column depth and the distance between the transmitter and receiver. Additionally, the effect of TRM on the spread of delays is validated in the actual sea environment.