一种改进的宽带波束形成方法

宽带信号具有目标回波携带的信息量大及混响背景相关性弱等特点，在声纳系统中应用越来越广泛。为了减小FIR滤波器的幅度和相位误差对宽带波束形成器性能的影响，采用线性约束最小方差自适应算法保证FIR数字滤波器的相位特性严格线性；采用基于幅度误差函数的代价因子自适应迭代算法使FIR数字滤波器通带内近似满足等纹波的幅度特性，达到FIR数字滤波器与设计指标要求最佳匹配的目的。对10阵元等间隔线阵的分析仿真结果表明该方法是有效的，并适用于其它阵型，对于声纳系统具有显著的应用价值。

An Improved Broadband Beamforming Method

In many appheations of sonar systems, broadband beaformer design is one of the most important issues due to its capabihty of retaining target signatures in the mainbeam region and suppressing noise and interference from sidelobe region. In order to decrease the influences of amphtude and phase errors of the FIR filter for broadband beamforming, the FIR digital filter with rigid hnear phase was obtained by linearly constrained minimum variance adaptation algorithm, and an iterative algorithm was used to design approximate equiripple FIR digital filters through adaptively obtaining optimum cost function based on amplitude error function. These improved approaches resulted in the best weights of the FIR filter to reach a best fit between the FIR digital filter response and the design requirements. Results of computer simulation for a 10-element equally spaced line array showed that these algorithms were effective, and can be applied to arbitrary array.