Planar array geometry optimization for region sound acquisition

Microphone arrays have been used in wide range of applications for sound acquisition and signal enhancement, the performance of which depends not only on the processing algorithms but also on the array geometry. A large number of efforts have been devoted to the development of beamforming and signal enhancement algorithms for processing microphone array signals in the literature. Relatively, few efforts have been made to investigate the problem of array geometry optimization. This paper studies the problem of geometry optimization for planar arrays and it develops a genetic optimization algorithm that can optimize the positions of the sensors, thereby maximizing the directivity factor (DF) with a constrained level of white noise gain (WNG) given the number of microphones, the region in which they should be placed, and the interested range of steering. Simulation results show that the optimized array geometry outperforms the uniform linear, the uniform circular and the rectangular grid geometries in terms of DF with the same number of sensors and the same constraint on the minimum level of WNG.