提高麦克风阵列波束指向性能的虚拟扩展方法

Improved steering based on the virtual extend method for the microphone array

针对宽带麦克风阵列如何在全频段保持一致性最优阵列处理问题,提出了麦克风阵列虚拟扩展稳健处理方法.该方法不仅在信号模型以及理论推导上深入分析了阵列虚拟扩展所带来的阵列误差、实现难点,而且提出了基于对角加载的稳健处理方法,并给出了加载电平的选取方法.最后对所提阵列虚拟扩展方法的处理性能进行了详细的理论分析和仿真实验,得出了阵列虚拟扩展可以有效地提高自适应波束形成器性能的结论.所提方法不仅适用于均匀线阵,而且也可直接推广应用于其他任意构型的自适应阵列;不仅适用于单信源场景,同时也适用于多信号源场景.

For the broadband microphone array,how to maintain the consistency of optimal array processing in the whole frequency band is the key problem,so an efficient virtual array extending method is put forward.This method is not only suitable for the single source scenarios,but also suitable for the multi signal source scene.Therein,from the signal model and the theoretical derivation,the problem which is caused by array virtual extending is analyzed deeply,such as array error and difficulty of its realization,then a robust method based on diagonal loading is proposed,and the method of how to select the load level is also given.Finally,the processing performance of the proposed virtual array extension method is tested and verified by theoretical analysis and detailed simulation results,and the conclusion is obtained that virtual array extension can improve the adaptive beamformer performance effectively.The proposed method is not only used for the uniform linear array,but also can be applied to the adaptive array with an arbitrary configuration.