Hafezi Sina, Moore Alastair H, Naylor Patrick A
Department of Electrical and Electronic Engineering, Imperial College London, SW7 2AZ, United Kingdom.
J Acoust Soc Am. 2021 Apr;149(4):2292. doi: 10.1121/10.0004214.
A conventional approach to wideband multi-source (MS) direction-of-arrival (DOA) estimation is to perform single source (SS) DOA estimation in time-frequency (TF) bins for which a SS assumption is valid. Such methods use the W-disjoint orthogonality (WDO) assumption due to the speech sparseness. As the number of sources increases, the chance of violating the WDO assumption increases. As shown in the challenging scenarios with multiple simultaneously active sources over a short period of time masking each other, it is possible for a strongly masked source (due to inconsistency of activity or quietness) to be rarely dominant in a TF bin. SS-based DOA estimators fail in the detection or accurate localization of masked sources in such scenarios. Two analytical approaches are proposed for narrowband DOA estimation based on the MS assumption in a bin in the spherical harmonic domain. In the first approach, eigenvalue decomposition is used to decompose a MS scenario into multiple SS scenarios, and a SS-based analytical DOA estimation is performed on each. The second approach analytically estimates two DOAs per bin assuming the presence of two active sources per bin. The evaluation validates the improvement to double accuracy and robustness to sensor noise compared to the baseline methods.
一种传统的宽带多源（MS）到达方向（DOA）估计方法是在时频（TF）单元中执行单源（SS）DOA估计，对于这些单元，单源假设是有效的。由于语音稀疏性，此类方法使用W不相交正交性（WDO）假设。随着源数量的增加，违反WDO假设的可能性也会增加。如在短时间内多个同时活跃的源相互掩蔽的具有挑战性的场景中所示，一个被强烈掩蔽的源（由于活动或安静的不一致性）在一个TF单元中很少占主导地位是有可能的。基于单源的DOA估计器在这种场景中无法检测或精确定位被掩蔽的源。针对球面谐波域中一个单元内基于多源假设的窄带DOA估计，提出了两种解析方法。在第一种方法中，使用特征值分解将多源场景分解为多个单源场景，并对每个场景执行基于单源的解析DOA估计。第二种方法假设每个单元存在两个活跃源，对每个单元解析估计两个DOA。评估验证了与基线方法相比，在精度提高一倍以及对传感器噪声的鲁棒性方面的改进。
