Effects of Sensor Position Errors on Farfield/Nearfield Wideband Beamformers for Microphone Arrays

It is well known that the presence of sensor position errors may lead to failure of farfield/nearfield wideband beamformers for microphone arrays. Therefore, many efforts have been made to design wideband beamformers for microphone arrays robust against sensor position errors in recent years. This paper presents the findings obtained on the study and analysis of the effects of sensor position errors to the performance of farfield/nearfield wideband beamformers for microphone arrays. Several useful properties have been derived through the conduct of a comprehensive statistical analysis, including the bias and variance analysis of array response, to provide in-depth insights into the robustness characteristics of farfield and nearfield wideband beamformers in the presence of sensor position errors. The analysis does not assume any specific array geometry and is thus applicable to arrays with arbitrary geometries. Numerical examples obtained via Monte Carlo simulations are presented to verify the proposed theoretical analysis. This paper is helpful to better understand the effects of sensor position errors on wideband beamformers and useful in microphone array design.