基于凸优化的最小旁瓣恒定束宽时域宽带波束形成

Broadband Beamforming with Minimum Sidelobe and ConstantBeamwidth Based on Convex Optimization

提出了基于凸优化的适用于任意结构基阵的最小旁瓣恒定束宽时域宽带波束形成方法.首先将基阵波束响应表达成一组有限脉冲响应(FIR)滤波器权值的线性函数,然后采用基于恒定束宽限制条件的最小旁瓣优化准则设计FIR滤波器权值.同时对滤波器系数进行范数约束以及对干扰方向设置展宽零陷来提高波束形成器的鲁棒性.将期望波束响应的设计过程与实际波束响应的逼近过程融合在一起进行优化搜索,获得了全局最优解.该波束形成器设计问题被转化成凸优化问题求解,仿真结果验证了所提方法的有效性.

A broadband beamforming algorithm in time-domain with minimum sidelobe and constant beamwidth on convex optimization is proposed.The array response is expressed as a linear function of a set of the finite impulse response（FIR）filter weights.The filter weights are designed in the optimized constraint beamwidth and minimum sidelobes minimizing the sidelobes while guaranteeing the beamwidth invariance.Norm constraint on tap weights and nulls widening constraint in the direction of the interference are also imposed to improve the robustness of the beamformer.The construction process of the desired response and the approaching process of the actual response are combined together to get the global optimal solution.Computationally efficient convex formulation for beamformer design problem is derived.Simulation results demonstrate the satisfactory performance of the proposed algorithm.