稳健的宽带恒定束宽波束形成算法

Robust Wideband Constant Beamwidth Beamforming Algorithm

针对运动目标入射及存在信号波达方向(DOA)估计误差时传统波束形成器性能下降的问题,提出一种稳健的宽带恒定束宽波束形成算法。该算法首先在目标入射角可能存在的范围内选取离散点,设定相应的期望及零陷响应,再结合空间响应变化(SRV)约束,将算法在信号带宽内不同频点的阵列响应约束简化为对某一参考频点的约束,并约束权矢量模值以抑制随机噪声,最后分别利用内点法和拉格朗日乘子法求解最优权矢量,实现稳健的宽带恒定束宽波束形成。实验结果表明该算法可以有效实现对运动目标的空域滤波,具有良好的恒定束宽特性及较高的阵列输出性能。

A robust wideband constant beamwidth beamforming algorithm is proposed to solve the problem of performance degrade of traditional wideband beamforminers when there exists direction of arrival （DOA）estimation error.Beam response at the look direction and nulling is imposed by selecting discrete point at the range of DOA angles.With the spatial response variation constrain,the response at different frequencies can be simplified as a reference frequency.Then the beamformer can be obtained combining with the norm constraint of the weight vector.Finally,the optimal weight can be solved with the methods of interior-point and Lagrangian.Experiments illustrate that the algorithm gets an available spatial filter result for moving targets,and achieves a preferable constant beamwidth performance and a high output signal to interference plus noise ratio.