自由度和互耦联合优化的三阶嵌套阵  

Three-level Nested Array: Optimization for Degree of Freedom and Mutual Coupling

作　　者：张宇乐 胡国平[1] 周豪[1] 赵飞龙 ZHANG Yule;HU Guoping;ZHOU Hao;ZHAO Feilong(Air and Missile Defense College,Air Force Engineering University,Xi’an,Shaanxi 710051,China;Unit 93951 of PLA,Geermu,Qinghai 816000,China)

机构地区：[1]空军工程大学防空反导学院,陕西西安710051 [2]中国人民解放军93951部队,青海格尔木816000

出　　处：《信号处理》2021年第2期234-241,共8页Journal of Signal Processing

基　　金：国家自然科学基金(61871395)。

摘　　要：针对现有嵌套阵自由度低、互耦率高的问题,本文采用均匀线阵进行级联,提出一种高自由度低互耦的三阶嵌套阵,该结构保留了嵌套阵的原有优势,具有物理阵元位置和自由度的闭式解,且极大程度地降低了阵元互耦。首先,对传统的回波信号模型引入互耦矩阵,建立了互耦条件下回波信号模型;然后,给出了三阶嵌套阵的布阵方式,并推导了"差联合阵列"结构下物理阵元的最佳配置和自由度的闭合表达式;最后,结合压缩感知技术进行波达方向估计。仿真实验表明,与现有嵌套阵相比,所提三阶嵌套阵在不增加物理阵元数目的条件下可以有效提升自由度,降低阵元互耦,从而提升角度估计性能。Aiming at the problems of low degree of freedom and high mutual coupling of current nested arrays, this paper adopts uniform linear array(ULA) to cascade, and proposes a three-level nested array with high degree of freedom and low mutual coupling. This structure not only retains the original advantages of nested array and has closed-form expression of physical array positions and degree of freedom, but also vastly reduces the mutual coupling. Firstly, the mutual coupling matrix is introduced to the traditional echo signal model, and the echo signal model under the mutual coupling condition is established. Secondly, the layout of the three-level nested array is given, and the optimal configuration and the closed-form expression of the degree of freedom of the physical array elements under the structure of "difference co-array" are derived. Finally, compressed sensing(CS) technology is used for direction of arrival(DOA)estimation. Simulation results show that compared with the existing nested arrays, the proposed three-level nested array can effectively improve the degree of freedom and reduce the mutual coupling without increasing the number of physical sensors, thus improving the performance of DOA estimation.

关 键 词：自由度 互耦率 三阶嵌套阵 压缩感知 波达方向估计 

分 类 号：TN953[电子电信—信号与信息处理]