一种准确鲁棒的宽带信号DOA估计算法

Accurate and Robust Algorithm for Broadband Signal DOA Estimation

信源的到达角(Direction of Arrive,DOA)信息在许多实际应用领域中具有重要作用,因此对DOA的准确估计是阵列信号处理领域的研究热点。针对传统信号子空间非相干处理方法(Incoherent Signals-subspace Method,ISM)在含有混响的低信噪比环境下对宽带信号进行DOA估计时存在的准确性低的问题,文中提出一种基于ISM算法的改进算法。该算法首先利用离散傅里叶变换将宽带信号分解为若干子频带;其次提出一种构建能量门限的方式,通过该能量门限筛选子频带并保留能量高于该门限的子频带;然后提出一种协方差矩阵重构方法,重构每一个子频带的协方差矩阵,通过TLS-ESPRIT算法估计每一个子频带的DOA参数;最后提出一种加权策略对多个子频带的DOA估计值进行处理,得到最终的DOA估计值。实验结果表明,该算法可以有效地提高宽带信号DOA的准确性,并且具有较好的鲁棒性。

The Direction of Arrive(DOA)information of the source plays an important role in many practical applications.Therefore,it is a research hotspot to estimate the DOA accurately in the field of array signal processing.In view of the low accuracy of the traditional ISM(Incoherent Signals-subspace Method)for DOA estimation of broadband signals in a low SNR and reverberation condition,this paper presented an improved DOA estimation algorithm based on the ISM.Firstly,the wideband signal is decomposed into several sub-bands by discrete Fourier transform.Secondly,a way to construct an energy threshold is proposed by which the sub-band is filtered by the energy threshold and the sub-band with energy above the threshold is reserved.Thirdly,a covariance matrix reconstruction method is used to reconstruct the covariance matrix of each sub-band,and the DOA parameters of each sub-band are estimated by the TLS-ESPRIT algorithm.Finally,a weighting strategy is proposed to process the DOA estimates of multiple sub-bands and the final DOA is estimate accurately.The experimental results show that the proposed algorithm can effectively improve the accuracy of broadband signal DOA and has better robustness.