Simplex underwater acoustic communications using passive time reversal

Abstract

Abstract. The spatial-temporal compression achieved by time reversal (TR) can reduce the inter-symbol interference (ISI) and increase the signal strength with low computation complexion. The active TR needs two-way propagation to implement focusing, so it cannot be used in simplex underwater acoustic communications. Based on the one-way propagation and spatial-temporal focusing property of passive TR, a simplex underwater acoustic communication scheme using passive TR is presented. The presented scheme is considered in two scenarios: uplink transmission from a single send-only element to an array and downlink transmission from an array to a single receive-only element, a multi-channel linear equalizer (LE) is adopted for uplink transmission and a single channel LE is used for downlink transmission to remove residual interference. Theory analysis shows that ideally the presented scheme can minimize the ISI and noise. Experiment results show that comparing with the performance of simplex communication scheme using passive TR alone and simplex communication scheme using a LE alone, the performance of presented scheme is the best.