Improving the robustness of beamforming using asymmetric sensor arrays

Abstract

Beamforming or phased array with an array of sensors is an advanced signal processing technique for directional signal transmission or reception. This directionality is achieved by phase shifts of received signals of each sensor for the constructive interference of wavefronts, resulting in the amplification of the signal from a particular direction. In this research, the use of an asymmetric sensor array is proposed to reduce the effects of “spatial aliasing,” which is typically encountered in the structural health monitoring practice when employing phased arrays. In this technique, a sensor array is asymmetrically and closely deployed for beamforming and for robust source localization. This sensor deployment has a great effect on reducing the spatial aliasing errors. Although many advanced signal processing algorithms have been developed in the past, an asymmetric sensor array proposed in this study is used to reduce the spatial aliasing error from the sensor deployment perspective. In order to demonstrate the proposed sensor array technique, several simulation and experimental investigations are carried out, and the performance comparison is made to demonstrate the superior robustness of the asymmetric sensor array.