低信噪比条件下宽带欠定信号高精度DOA估计

发布时间：2018-01-16 00:21

本文关键词：低信噪比条件下宽带欠定信号高精度DOA估计　出处：《电子与信息学报》2017年06期 　论文类型：期刊论文

【摘要】：为提高低信噪比条件下宽带欠定信号DOA估计精度,该文提出基于网格失配迭代最小化稀疏学习的宽带DOA估计方法。该方法首先对频域协方差矩阵进行矢量化处理实现虚拟阵列扩展,将欠定信号转换为超定信号。其次利用线性变换滤除含有噪声项的虚拟阵元,并对协方差估计误差进行了白化处理,抑制了信号中的干扰项。最后建立了包含不同频点联合稀疏参数和网格失配参数的贝叶斯层次架构,推导了联合稀疏参数、网格失配参数的最小稀疏表达式并进行了迭代学习。较传统方法,该方法不依赖任何先验信息,更好地抑制了虚拟阵元中的噪声和干扰,降低了网格失配对DOA估计的影响,在低信噪比条件下具有更高的DOA估计精度和分辨率。仿真实验验证了该方法的有效性。
[Abstract]:In order to improve the accuracy of DOA estimation for wideband underdetermined signals under low SNR. In this paper, a wideband DOA estimation method based on mesh mismatch iterative minimization and sparse learning is proposed. Firstly, the frequency domain covariance matrix is vectorized to extend the virtual array. The underdetermined signal is converted into the overdetermined signal. Secondly, the virtual matrix element with noise is filtered by linear transformation, and the covariance estimation error is whitened. Finally, the Bayesian hierarchy with different frequency joint sparse parameters and grid mismatch parameters is established, and the joint sparse parameters are derived. The minimum sparse expression of mesh mismatch parameters is studied iteratively. Compared with the traditional method, the proposed method does not rely on any prior information and can better suppress the noise and interference in the virtual array elements. The effect of grid mismatch on DOA estimation is reduced, and the accuracy and resolution of DOA estimation are improved under low SNR. The simulation results show that the proposed method is effective.
【作者单位】：空军预警学院;解放军94969部队;
【基金】：国家自然科学基金(61401504) 军内计划科研项目(2015XXX) 湖北省自然科学基金(2016CFB288)~~
【分类号】：TN911.7
【正文快照】： 1引言宽带信号具有抗干扰能力强、调制样式复杂、携带信息量大等特点,在雷达、通信、电子对抗侦察等领域具有十分广泛的应用,随之产生的宽带信号到达角(Direction Of Arrival,DOA)估计问题,尤其是基于稀疏重构算法的宽带信号DOA估计,成为了阵列信号处理中的一个研究热点[1,2

【相似文献】