针对现有单源情况下近场目标定位的窄带克拉美-罗界(Cramér-Rao Bound,CRB)都是基于均匀直线阵模型,且没能全面分析其CRB的特性和具体的影响因素。该文首先推导了基于窄带模型的单源费雪信息矩阵,进而通过求舒尔补和雅克比变换,得到非均匀线阵条件下近场测距和测向的非矩阵形式的闭式CRB解析式。通过对该式从阵列相关因素(如阵列结构、阵列孔径等)和目标信号相关因素(如目标信号频率和信噪比等)两方面进行分析,揭示了影响目标角度和距离估计性能的物理因素,为后续阵列及信号的设计提供了理论指导。在最大孔径给定的情况下,可通过设计合理的阵元配置方式,实现最优的测距和测向效果。蒙特卡洛仿真结果验证了理论分析和上述结论的正确性。
In view of the existing CRB(Cramér-Rao Bound) for near-field single source is based on the uniform linear array, and analyzes less fully the CRB's characteristics and the influence factors of specific. In this paper, non-matrix, closed-form expression of the deterministic CRB for the near-field narrow band model is deduced based on Fisher information matrix, Schur complement and Jacobi transform with non-uniform linear array. The behavior of the performance with respect to some features of interest are discussed, namely, the array geometry, the array aperture, the thinned factor, the target signal frequency and the signal to noise ratio. Through the reasonable array design scheme, the direction and range of the target are both estimated. The Monte-Carlo simulation results validate the effectiveness of the theoretical analysis and the conclusion.