基于自适应迭代的强弱信号波达方向估计

DOA Estimation for Strong and Weak Signals Based on Adaptive Iteration

针对强弱信号难以同时检测与估计的问题,本文提出一种基于自适应迭代的强弱信号波达方向估计方法.首先将空间角度离散化,根据信号相消的性质构造空间谱函数,然后通过自适应迭代抑制强信号的能量,最后计算不同角度对应的空间谱函数,利用其谱峰估计信号的波达方向.理论分析和仿真实验表明,本文方法无需信号源的先验信息,在低信噪比和少量快拍数的条件下,可以实现强弱信号DOA的高分辨估计,有效提高弱信号的检测概率和估计精度.

To detect and estimate weak targets from the strong ones,a newmethod based on adaptive iteration is proposed to estimate the DOA. Firstly,the space angle is dispersed and the spatial spectrum function is constructed based on the property of signal subtraction. Secondly,the energy of strong signal is suppressed through adaptive iteration. Finally,the value of spatial spectrum is calculated,and the DOAs of the signals are estimated through the peaks. Theoretical analysis and simulation results showthat the method can achieve high-resolution DOA estimation without the prior knowledge of angles,even with the lowsignal-to-noise-ratio（ SNR） and small snapshots. In addition,the proposed method can improve the detection probability and estimation accuracy of weak signal.