Experimental results of time reversal and optimal inverse filtering performed in a one dimensional waveguide

Abstract

<jats:p>Time reversal is a common technique for improving the temporal and spatial focusing in the transmission of signals and has been demonstrated in a wide variety of applications. An alternative to time reversal is inverse filtering. Inverse filters are similar to time reversal filters in that they also remove the phase aberations, but they have the added advantage that they also counter the amplitude abberations such that the resulting response through the system has a flat response in the frequency domain. Inverse filtering also provides a means to develop a filter structure that provides a cross-talk cancellation system for multiple input/multiple output systems. In this presentation, results from experimental observations made within a one dimensional waveguide are compared with the commonly used technique of time reversal with an optimal inverse filtering technique. The aim of such experiments is to examine the performance of the time reversal and optimal inverse filtering techniques within a real waveguide and compare these against theoretical predictions. The experiments performed have been developed with a view to extend the research to underwater acoustic communications.</jats:p>