宽带共形阵基于SRV约束的自适应波束设计

Adaptive beamformer design for wideband conformal array based on SRV constraint

自适应波束形成可以有效抑制非期望信号方向上的干扰信号。针对采用节拍延迟线(Tapped Delay Line,TDL)结构和复数加权系数的宽带共形阵,本文提出一种基于空间响应偏差SRV(Spatial Response Variation)约束的自适应频率不变波束形成器(Frequency Invariant Beamformer,FIB)优化设计方法。该自适应FIB在参考频率上保持预测信号方向无偏响应以及旁瓣级恒定这2个限制条件下,根据对波束形成器输出功率值与平均空间响应偏差值这2项的加权和进行最小化处理的准则进行设计。通过将这种FIB设计问题转化为标准二阶锥规划(Second Order Cone Programming,SOCP)形式后,可以采用内点方法对其进行有效求解。仿真结果验证了本文方法对于宽带共形阵自适应FIB设计的有效性。

Adaptive beamforming is a key technique for rejecting interference signals whose incident directions differ from that of the desired signal.To the wideband conformal array with tapped delay line(TDL) structure and complex weighting coefficients,we propose an adaptive frequency invariant beamformer(FIB) design based on the spatial response variation(SRV) constraint.This proposed adaptive FIB design is performed according to the rule of minimizing the weighted sum of beamformer's output power and averaged SRV value while keeping the distortion less response constraint in the presumed direction of desired signal and keeping the sidelobe level constant both at the reference frequency.After being converted to the forms of standard second order cone programming(SOCP),this beamformer design problem can be solved with the interior-point method.The computer simulation results demonstrate the effectiveness of our adaptive FIB design method for wideband conformal array.