球形传声器阵列三维波束形成性能

Three-dimensional beamforming performance of spherical microphones array

为分析球形阵列结构参数对三维波束形成声源识别性能的影响,基于延迟求和波束形成理论,仿真分析了主瓣宽度和最大旁瓣水平随阵列直径的变化规律,结果表明:在传声器布置形式一致的情况下,直径越大,阵列空间分辨率越好,但对旁瓣抑制能力越弱;模拟计算了5种典型球形阵列的阵列模式径向投影及最大旁瓣水平,结果显示:传声器均匀分布球形阵列的性能最好,在50～100rad/m的波数范围内,最大旁瓣水平约为-12dB,在波数高达220rad/m时最大旁瓣水平也低于-6dB。提高球形阵列传声器分布的均匀程度和密集程度能显著提高阵列性能。

In order to analyze the effect of spherical array structure parameters on the three-dimensional beamforming noise source identification performance, based on the Delay-and-Sum beamforming theory, the mainlobe width and the maximum sidelobe level were simulated and analyzed using varied diameters. Results indicated that the larger the diameter, the better the spatial resolution became. However, a larger diameter caused a weaker sibelobe inhibitory ability Furthermore, the radial profile of array pattern and the maximum sidelobe level for five typical spherical arrays were studied. Results showed that the uniformly distributed microphones array had the best performance. When the wavenumber was 50-100 rad/m, the maximum sidelobe was about -12 dB, and when the wavenumber was up to 220 rad/m, the maximum sidelobe was still less than -6 dB. Therefore, increasing the uniformity and density of the microphones distribution can significantly improve the beamforming performance.