基于最小二乘的子带SDL恒定束宽波束形成  

Least Squares Based Subband Frequency Invariant Beamforming with Sensor Delay Lines

作　　者：陈晖[1,2] 刘成城[1] 李冬海[1] 汪婉秋[1] 

机构地区：[1]解放军信息工程大学导航与空天目标工程学院 [2]海军92773部队

出　　处：《现代雷达》2013年第11期44-48,51,共6页Modern Radar

基　　金：国家863项目(2011AA7031015)

摘　　要：针对宽带恒定束宽波束形成通常需要大量阵元或延迟线所带来的硬件开销较大的问题,提出一种基于约束最小二乘的子带阵元延迟线(SDL)恒定束宽波束形成器设计方法。该方法首先建立子带SDL模型,利用子带滤波器组将阵元接收信号进行分解与重构,然后,推导了子带SDL模型的阵列响应,最后,结合空间响应变化和约束最小二乘算法进行恒定束宽波束形成。由于将滤波器组的冲击响应直接作为优化参量,可有效降低分解与重构产生的误差,为了衡量阵列响应的波动程度,文中提出归一化波动程度的概念。仿真结果表明,子带波束形成器不仅具有比全带波束形成器更好的主瓣频率不变性,更窄的主瓣宽度以及更低的旁瓣增益,而且可以大大降低硬件开销。Wideband beamforming usually needs a large number of sensors or tapped delay lines, which lead to heavy hardware load. To alleviate this problem, a subband sensor delay lines （SDL） based frequency invariant beamformer （FIB） design method is proposed by constrained least squares approach. Firstly, a subband SDL model is developed. Based on this novel model, received signal is decomposed by analysis filter banks and recombined by synthesis filter banks. Then the array response of the subband SDL beamformer is derived. In the end, spatial response variance and constrained least squares algorithm are applied in the subband frequency invariant beamforming. The concept of normalized beam pattern variance is raised to measure the variance of array response. Simulation results demonstrate that, comparing with fullband beamformer, subband beamformer has better frequency invariance in mainlobe, mianlobe resolution and sidelobe attenuation. Moreover, subband beamforming can release heavy hardware load largely.

关 键 词：恒定束宽波束形成器 阵元延迟线 子带滤波器组 约束最小二乘 归一化波动程度 

分 类 号：TN911.7[电子电信—通信与信息系统]