嵌套阵列最大似然估计测向算法

发布时间：2018-05-20 03:28

本文选题：嵌套阵列 + 最大似然估计　；参考：《航空学报》2017年11期

【摘要】：针对在辐射源个数未知的条件下嵌套阵列难以估计多个辐射源角度的问题,提出了基于最大似然估计(MLE)的嵌套阵列角度估计算法。算法在嵌套阵列模型的基础上,首先通过推导阵列截获多辐射源信号的最大似然函数及其梯度,利用最速下降法估计出空域中所有潜在辐射源的角度;然后,通过多元假设检验,利用最大似然比与门限进行比较,确定出空域中所有潜在辐射源中某一时刻发射信号的活跃辐射源角度,排除其余噪声形成的虚假辐射源角度,解决了在辐射源个数未知条件下嵌套阵列对多个辐射源角度估计问题。仿真结果表明:与传统多重信号分类(MUSIC)算法相比,该算法在辐射源数目未知、存在相干信号、低信噪比(SNR)、低快拍数条件下,均具有较好的角度估计精度,并且算法形成的虚拟阵列自由度是空间平滑MUSIC算法的2倍;多元假设检验法比传统信源数目估计算法在低信噪比条件下和处理相干信号方面具有明显优势。
[Abstract]:In order to solve the problem that it is difficult for nested arrays to estimate the angles of multiple emitters under the condition of unknown number of emitter sources, an algorithm for angle estimation of nested arrays based on maximum likelihood estimation (MLEs) is proposed. Based on the nested array model, the maximum likelihood function and its gradient of the array intercepting multiple emitter signals are derived, and the angle of all potential radiation sources in the spatial domain is estimated by the steepest descent method. By multivariate hypothesis test, the maximum likelihood ratio is compared with the threshold, and the active emitter angle of all potential radiation sources in airspace is determined at a certain time, and the false emitter angles formed by other noises are excluded. The problem of estimating the angles of multiple emitter sources by nested arrays with unknown number of emitter sources is solved. The simulation results show that the proposed algorithm has better angle estimation accuracy under the condition of unknown number of emitter sources, coherent signal, low signal-to-noise ratio (SNR) and low shot number. Moreover, the degree of freedom of virtual array formed by the algorithm is twice that of the spatial smooth MUSIC algorithm, and the multivariate hypothesis verification method has obvious advantages over the traditional estimation algorithm in terms of low signal-to-noise ratio (SNR) and coherent signal processing.
【作者单位】：合肥电子工程学院;安徽省电子制约技术重点实验室;
【基金】：国家自然科学基金(61671453) 安徽省自然科学基金(1608085MF123)~~
【分类号】：TN97

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