基于麦克风阵列的宽带健壮自适应波束形成算法

研究了用于麦克风阵列语音增强的宽带健壮自适应波束形成算法。该算法结合频率聚焦技术和对角加载技术。在此基础上,通过优化最坏情况下的波束性能确定对角加载因子,求得了最优加载因子的近似解析表达式。和相关算法相比,使用最坏情况性能优化的算法具有更好的语音增强性能,由于求得了最优加载因子的解析解,还具有运算量低、容易实现等优点。同时,该解析解揭示了哪些因素可以影响最优加载因子,以及如何影响。计算机仿真验证了该结果的正确性和有效性。

Approach of wideband robust adaptive beamforming based on microphone arrays

The approach of wideband robust adaptive beamforming (RABF) for speech enhancement based on micro-phone arrays was investigated. It combined the technologies of frequency focusing and diagonal loading, with the former aiming at frequency domain consistency of the beampattern, whereas the latter at robustness against steering vector mis-matches. The loading level was determined based on worst-case performance optimization and a simple closed-form so-lution to the optimal loading was derived after some approximations. Compared with many existing methods in this field, the one with the proposed analytical solution is computationally less demanding and achieves better performance in speech enhancement. Moreover, the analytical solution reveals how different factors affect the optimal loading. Numeri-cal examples confirm its correctness and effectiveness.