Greedy Array Geometry Optimization Based on Maximin Principle for Region Sound Acquisition

This paper presents a method to improve sound acquisition in microphone arrays by optimizing their geometry. We aim to have a constant array gain in the target region by maximizing the minimum full-band array gain, iteratively and sequentially. To find the optimal array geometry, we develop a novel greedy algorithm with two main steps: forward addition and backward deletion. In the forward addition step, we select a new sensor from a pool of candidates to enhance the array gain in the minimum direction identified in the previous step. In the backward deletion step, we remove a sensor that contributes the least after several forward additions. Simulation results indicate that the full-band array gain of the optimized array remains nearly constant within the desired region. Additionally, the beampattern of the optimal array exhibits good rotational invariance in this region.