Time-Frequency-Bin-Wise Linear Combination of Beamformers for Distortionless Signal Enhancement
Time-Frequency-Bin-Wise Linear Combination of Beamformers for Distortionless Signal Enhancement
复制标题
用于无失真信号增强的波束形成器的时频分箱线性组合
DOI：
10.1109/taslp.2021.3126950
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
and Shoji Makino
中科院分区：
文献类型：
--
作者：
Kouei Yamaoka;Nobutaka Ono;and Shoji Makino
在本文中，我们解决了不确定情况下的信号增强问题，并提出了新的波束形成算法。在（超过）确定的情况下的波束形成可以成功地减少噪声信号而不失真期望的信号，这被认为是期望的特性，特别是对于自动语音识别系统。即使在不确定的情况下，时频 (TF) 掩蔽也能在降噪方面取得出色的性能，尽管它往往会产生伪影。集成这两种方法以受益于它们的优点，我们在这里提出时频分箱切换（TFS）和时频分箱线性组合（TFLC）波束形成。在所提出的方法中，我们在每个 TF bin 的多个波束形成器中利用波束形成器的最佳组合，每个波束形成器都抑制特定的干扰组合。首先，我们提出了使用多个空间滤波器的信号增强的一般公式。然后在统一的最小方差准则下考虑设计空间滤波器并估计组合它们的合适权重的联合优化问题。最后，我们提出了解决该问题的有效算法。在实验中，我们使用客观标准来量化增强函数引起的信号失真量，并证实所提出的方法可以有效抑制干扰，而不会使目标信号失真。
In this paper, we address signal enhancement in underdetermined situations and propose new beamforming algorithms. Beamforming in (over) determined situations can successfully reduce noise signals without distortion of a desired signal, which is known to be a desirable property, especially for automatic speech recognition systems. Even in underdetermined situations, time-frequency (TF) masking attains outstanding performance in noise reduction, although it tends to generate artifacts. Integrating these two approaches to benefit from both their advantages, we here propose time-frequency-bin-wise switching (TFS) and time-frequency-bin-wise linear combination (TFLC) beamforming. In the proposed methods, we utilize the best combination of beamformers among multiple beamformers at each TF bin, each of which suppresses a particular combination of interferers. First, we propose a general formulation of signal enhancement employing multiple spatial filters. Then a joint optimization problem of designing the spatial filters and estimating the suitable weights to combine them is considered under a unified minimum variance criterion. Finally, we present efficient algorithms to solve the problem. In experiments, we used an objective criterion that quantifies the amount of signal distortion caused by the enhancement function and confirmed that the proposed methods effectively suppress interferers without distortion of the target signal.