非规则部分校准阵列下的宽带LFM信号二维DOA估计

提出了一种宽带线性调频（LFM）信号的二维波达方向（DOA）估计新方法.该方法在空域和时域同时对信号进行采样,并利用观测样本的分数阶Fourier域峰值构造出新的时频空DOA矩阵,进而通过特征值分解的方法实现多个LFM信号的DOA估计.该方法充分地挖掘了观测信号所包含的时频信息,降低了对阵列结构和阵元一致性的约束,使其适用于阵元几何分布不规则且大部分阵元未经校准的阵列.此外,该方法无需谱峰搜索和二维参数配对,计算简单且估计精度较高.仿真结果显示,在DOA估计的均方根误差（RMSE）相同时,与传统方法相比,该方法可获得6～8 dB的信噪比增益.

2-D DOA Estimation of Wideband LFM Signals in Partly Calibrated Irregular Array

A novel 2-D direction of arrival（DOA）estimation method for wideband linear frequency modula-tion（LFM）signals was proposed.The incident signals were sampled in spatial domain and time domain synchronously,and a new time-frequency spatial DOA matrix was constructed based on the peak values of the obser-vation samples in fractional Fourier domain.Moreover,the source DOAs were estimated by the eigen-decomposition process.Owing to sufficient mining of the time-frequency information included in observed signals,this method has a lower constraint of array structure,and can be applied to partly calibrated array with arbitrary geometry structure.Moreover,no spectral peak searching is needed in the method,and the parameters match automatically in the proc-ess.Simulation results show that the DOA estimation method in this paper can obtain 6—8 dB signal-to-noise ratio gain compared with the conventional method.