基于信号时频表示的宽带源波达方向估计

提出一种时频域宽带源波达方向(DOA：Direction of Arrival)估计算法。该算法通过计算参考阵元和其它阵元的互Wigner-Ville分布，构造出一种新的时频域数据向量模型，并利用Chirp信号的局部窄带特性，在信号的主要能量聚集区选择时频点构造时频相关矩阵代替传统的阵列相关矩阵，进行特征分解实现信号的DOA估计。该方法同时在空域和时频域进行处理，充分利用了时频分布的能量聚集性，不但实现了非平稳信号时频域的分离，还有效地提高了信噪比，增强了算法对噪声的稳健性。仿真结果验证了新方法的有效性。

Direction of Arrival Estimation for Wideband Sources Based on Time-Frequency Signal Representation

A novel wideband Direction of Arrival estimation method is proposed by exploiting the signals different time-frequency signatures. The data vector model is constructed in time-frequency domain by computing the cross Wigner-Ville distribution of the output of the reference sensor and those of other sensors. Accordingly the time-frequency correlation matrix for each source is formed by choosing the t-f points residing on its own auto-term region, separately. Then the traditional subspace based method is applied on this t-f correlation matrix to obtain the DOA estimates of multiple wideband sources. In contrast to the traditional method, the proposed method combines time-frequency analysis into array processing, and the DOA estimating performance is improved due to localizing the source energy while spreading the noise power in the time-frequency domain. Furthermore, the method is robust against noise and has a low computation load in constructing the time-frequency correlation matrix compared to the traditional t-f method. The computer simulation verified the efficiency of the new method.