Window-Based Constant Beamwidth Beamformer
Window-Based Constant Beamwidth Beamformer
复制标题
基于窗口的恒定波束宽度波束形成器
DOI：
10.3390/s19092091
复制
发表时间：
2019-05-01
期刊：
影响因子：
3.9
通讯作者：
Chen, Jingdong
中科院分区：
文献类型：
--
作者：
Long, Tao;Cohen, Israel;Chen, Jingdong
波束形成器被广泛用于增强来自某个方向的信号，抑制来自其他方向的噪声和干扰信号。恒定波束宽度波束形成器可以在很宽的频率范围内实现固定波束宽度。现有的恒波束宽度波束形成器设计方法大多是基于计算复杂度高的优化算法，且往往对传声器失配很敏感。现有的其他方法是根据频率调整传感器的个数，简化了设计，但无法控制副瓣电平。在此，我们提出了一种基于窗口的技术来获得波束宽度常数，该技术将不同形状的标准窗口函数应用于不同的频率箱作为麦克风的实际加权系数。这样，我们不仅可以保持波束宽度恒定，而且还可以控制副瓣电平。仿真结果表明，与现有方法相比，该方法具有较低的旁瓣电平、较高的指向性因子和较高的白噪声增益等优点。
Beamformers have been widely used to enhance signals from a desired direction and suppress noise and interfering signals from other directions. Constant beamwidth beamformers enable a fixed beamwidth over a wide range of frequencies. Most of the existing approaches to design constant beamwidth beamformers are based on optimization algorithms with high computational complexity and are often sensitive to microphone mismatches. Other existing methods are based on adjusting the number of sensors according to the frequency, which simplify the design, but cannot control the sidelobe level. Here, we propose a window-based technique to attain the beamwidth constancy, in which different shapes of standard window functions are applied for different frequency bins as the real weighting coefficients of microphones. Thereby, not only do we keep the beamwidth constant, but we also control the sidelobe level. Simulation results show the advantages of our method compared with existing methods, including lower sidelobe level, higher directivity factor, and higher white noise gain.