一种改进的稳健高分辨力DOA估计算法

A modified robust high-resolution DOA algorithm

介绍了一种基于最大后验概率准则的约束最优空间处理(Spatial Processing-Optimized and Constrained,SPOC)DOA算法。这种算法将阵列接收到的空间能量近似为来自远场的密集分布的独立信号源发出的信号,在极限情况下,这些点源是连续分布的。算法应用最大后验概率准则,在满足接收信号能量不变的情况下,使得接收到的总功率最小,通过估计每个点源的能量完成对来波方位的估计。算法只针对单快拍数据进行处理,因此避免了目标运动以及环境非平稳性带来的影响。针对算法在低信噪比下不稳定的缺点,使用对角加载技术(diagonal loading)进行了改进,增强了算法的稳健性。使用单个发射换能器和接收水听器进行了水池实验,实验显示DL-SPOC算法相比于MVDR、CBF等算法拥有更高的角度分辨力。

A new DOA estimation algorithm caIled SPOC （spatial processing--optimized and constrained） which is based on MAP （maximum a posteriori） criterion is introduced. In the algorithm the spatial energy received by array is divided into a large number of uniformly spaced cells, each of which is assumed to be transmitted by a point source. Maximum a posteriori criterion is used in the algorithm, which minimize the total power received while maintain the signal power received in the desired direction. The DOA estimation is accomplished by estimating each of the point source＇s energy. The algorithm avoids estimation errors caused by target movement or non-stationarity of environment by using single snapshot. In this paper, diagonal loading approach is used to enhance the stability of the algorithm in low SNR （signal to noise ratio）. An experiment is taken in a water tank by using only one transducer and one receiver. The experiment shows that DL-SPOC has higher angular resolution than other algorithms such as CBF and MVDR.