相干语音信号的两阵元DOA估计新算法

Novel Direction of Arrival Estimation Algorithm of Coherent Speech Signals with Two Array Elements

针对语音信号非平稳性、非调制性及高分数带宽比的特点,提出一种新的基于两阵元的相干语音信号DOA估计算法。该算法先从接收信号中选出低频部分能量较大且功率谱分布较均匀的帧为最优帧,并分解为互不重叠的窄带分量,利用希尔伯特变换将各窄带转换成解析信号,将信号的不同频率等效为虚拟阵列的各个阵元,对虚拟阵列接收信号去相干处理后进行DOA估计。本文从信源个数、划分窄带数、信噪比等方面对提出的算法进行仿真实验研究,仿真结果及分析表明该算法对高信噪比的相干语音信号DOA估计具有一定的适用性,克服了两阵元只能估计单声源的不足,实现了多个相干声源的DOA估计。

Aimed at the features of speech signals which were non-stationary, unmodulated and had high fractional band- width, a novel direction-of-arrival （DOA） algorithm of coherent speech signals was proposed which was based on two array elements. The algorithm first selected the optimal frame which had higher energy and more uniformly distributed power spectrum at the range of low frequencies from the received signals of the two array elements, then divided it into the non-o- verlapping narrowband portions, afterwards used the Hilbert transform to convert them into analytic signals and made the different frequencies of the signals equivalent to each array elements of the virtual array, at last eliminated the coherence of the signals to obtain DOA estimation. A research of simulation experiment was given from multiple aspects, e.g. number of signals, sub-band division, signal-to noise ratio （SNR） etc and the effectiveness of the new algorithm was verified. From the simulation results and analyses, it is showed that the proposed algorithm has fine applicability, particularly when SNR is high. It is able to overcome the problem which two array elements can estimate only one signal source and achieve the DOA estimation of multiple coherent signals.