旁瓣电平软约束下干扰功率搜索的波束形成

实际中，期望信号或干扰的先验方向信息往往不能精确已知(即存在阵列流形误差)，当信噪比超过一定门限时，线性约束自适应波束形成器对阵列流形误差有高敏感性从而导致输出信干噪比下降。为解决上述问题，该文提出一种旁瓣电平软约束条件下搜索人工干扰功率值的波束形成方法。在粗估干扰来波方向的基础上，约束旁瓣最大峰值起伏在一定范围内，采用子空间投影和加宽干扰零陷区的技术提高波束形成器的鲁棒性，通过粗、精两种模式的搜索获得干扰零陷区的注入功率值估计，具有良好的干扰抑制效果和对阵列流形误差不敏感的特性。计算机仿真验证了方法的有效性和鲁棒性。

Artificial Interference Power Estimation for Beamforming under Sidelobe Soft Constraint

Often in practice the directional knowledge of signal of interest or interferences is imprecise,the adaptive beamformer with linear constraint is hypersensitive to the array imperfection which leads to the output Signal-to-Interference-plus-Noise Ratio(SINR) decreases when the input Signal-to-Noise Ratio(SNR) exceeds a certain threshold.In order to improve the robustness of the beamformer,a new method for estimating the artificial interference power under sidelobe soft constraint is proposed.Based on the prior coarse knowledge of Direction of Arrival(DOA) of the interferences and using the subspace projection and the null area extension techniques,the artificial interference power can be obtained through the iterative procedure under the soft constraint of the maximum peak undulation in sidelobe area.The method is not sensitive to the look direction mismatch and the sensors gain error with low sidelobe level and deep null.Numerical examples demonstrate its effectiveness and robustness comparing with other methods.