强相干干扰下弱信号波达方向估计∗

摘要

针对强相干干扰背景中弱信号的波达方向(DOA)估计问题，提出了一种基于迭代算法的弱信号DOA估计新算法。首先估计强相干干扰的波达方向，然后将阵列划分成两个子阵，进行子阵波束形成来抑制干扰并提高待估计的弱信号的信干噪比，最后利用子阵相位中心偏移进行 DOA估计，为提高弱信号的DOA估计精度对以上过程进行迭代运算。该算法在强相干干扰环境下能有效进行弱信号 DOA估计，而且估计精度较高。理论分析和计算机仿真结果验证了算法的正确性和有效性。%For the DOA estimation of weak signals in the presence of coherent intensive interferences,a novel DOA estimation algorithm of weak signals based on iteration processing is proposed.The DOA of coherent in-tensive interferences are obtained at first.Then,the antenna array is divided into two equal-size sub-arrays, and sub-array beamforming is used to suppress the interferences and improve the SINR of weak signals.The DOA of weak signals is got through the phase center displacement of the sub-array at last.Phase comparison and beamforming are iteratively performed to get the accurate angle estimation of weak signals.The proposed approach has the ability to make DOA estimation under coherent interferences with high accuracy.Both the theoretical analysis and the simulation results verify the validity and feasibility of the proposed method.