分布式传声器阵列的低频宽带信号方位估计

现有的预防道路交通安全事故、治理道路交通噪声污染等问题的解决方案是从视觉维度监控重点区域并通过声音维度确定事件触发类型与位置。为了实现公路异常声源的实时监测，提出了一种基于双尺度旋转不变信号参数估计旋转不变子空间技术(Estimation of Signal Parameters via Rotational Invariance Techniques, ESPRIT)的低频宽带声源波达方向(Direction of Arrival, DOA)估计算法，该算法适用于三个矩形子阵呈三角形分布的分布式阵列。算法利用该分布式阵列具有的子阵内相邻阵元间距、相邻子阵间距两种尺度对应的空间平移不变性分别进行方向余弦估计，并利用基于阵型分布的解模糊策略实现高精度方位估计。仿真结果验证了算法的有效性，表明了基于该算法的分布式阵列DOA估计精度优于相同阵元数与阵元间距的单个均匀矩形阵，分析了估计精度与分布基线长度的关系，体现了算法的实际工程应用价值。

Low frequency wideband signal DOA estimation by using distributed microphone arrays

The existing solutions to prevent road traffic accidents and control road traffic noise pollution are to monitor the key areas by visual judgment and determine the event trigger type and location by auditory judgment. In order to realize the real time monitoring of highway abnormal sound sources, a direction of arrival (DOA) estimation of signal parameters via rotational invariance techniques of low frequency broadband sound source based on dual scale estimation of signal parameters via rotational (ESPRIT) is proposed, which is suitable for the distributed array composed of three rectangular sub-arrays with a triangular distribution. The algorithm uses the spatial translation invariance corresponding to the two scales of the distance between adjacent elements in the sub-array and the distance between adjacent sub-arrays in the distributed array to estimate the direction cosine respectively, and uses the defuzzification strategy based on the array distribution to achieve high-precision azimuth estimation. The simulation results verify the effectiveness of the algorithm, show that the DOA estimation accuracy of the distributed array based on the algorithm is better than that of a single uniform rectangular array with the same number of array elements and same array-element spacing, and analyze the relationship between the estimation accuracy and the length of the distributed baseline, which reflects the practical engineering application value of the algorithm.