针对存在导向矢量误差时自适应相干检测器(ACE)的检测性能下降问题,该文提出一种基于椭球不确定集约束的鲁棒ACE设计方法。该方法在深入分析ACE检测器工作原理的基础上,利用导向矢量的尺度变化不影响ACE检测器输出这一特点,建立鲁棒ACE检测器模型并将其转化为凸优化问题,最后采用牛顿一拉夫森方法对该问题进行求解。仿真实验结果表明,该方法可有效提高ACE检测器对导向矢量误差的鲁棒性。
Adaptive Coherence Estimator (ACE) often suffers considerable performance degradation in the presence of steering vector errors. In this paper, a robust ACE detector based on the ellipsoid uncertainty set constraint is proposed. A detailed analysis of ACE detector is first conducted, which results in an interesting observation that scaling of the steering vector does not affect the statistical test of ACE. With this property exploited, a model for designing robust ACE detector is constructed and is subsequently converted into a convex optimization problem. Then, the solution to the problem is given with the powerful Newton-Raphson method. Simulation results show that the robustness of the proposed detector against the steering vector errors can be improved significantly compared with the standard ACE.