基于波束输出的高分辨定向方法及性能分析

A NEW DOA ESTIMATOR BASED ON BEAM OUTPUT

本文提出一种基于波束输出的高分辨定向方法。这种方法利用子阵形成子波束,并把该子阵看做为一个等效阵元。然后对多个等效阵元构成的新阵列利用目前典型的高分辨算法进行定向。我们对均匀线列阵进行了计算机仿真实验和水池高分辨阵列处理实验,研究结果表明,这样做可以获得性能上的较大提高。一方面,可提高原高分辨定向算法的估计精度、分辨概率并降低运算时间;另一方面,由于各个等效阵元的输出是由多个实际阵元输出加权平均得来的,因此基于等效阵元构成阵列的高分辨定向算法对各种阵列误差(如阵元位置误差、阵元指向性的不一致等)变得不十分敏感,从而有利于抑制阵列误差对高分辨定向算法的影响,对工程应用具有较强的适应性。文中对各种情况进行了较详细的统计性能分析和比较。

A new DOA estimator based on beam output is presented in this paper. It uses subarray to form beam and regards these subarrays as equivalent sensors. So a new array is generated. Employing original high-resolution DOA estimators, such as MUSIC, on the new array, DOAs are then obtained. Monte Carlo test and underwater high-resolution array processing experiment are made on linear equispaced array (LEA) to check the performance of the new method. It is shown from the result of tests that the new method possesses some advantages over the original one. First, it improves the estimation precision and resolution of original method; Second, it reduces the burden of computation; Third, the most important one, it becomes not sensitive to various array errors, such as sensors position/phase error, inconsistency of sensors directionality, etc.. So it is promising on engineering application. Statistical performance analysis and underwater experimental results are given in the paper to verify the conclusion.