Jiang Yuchen, Fu Jun, Li Bao, Jiang Pengfei
School of Electrical Engineering, Naval University of Engineering, Wuhan 430033, China.
College of Intelligent Science and Technology, National University of Defense Technology, Changsha 410073, China.
Sensors (Basel). 2024 Jan 19;24(2):0. doi: 10.3390/s24020650.
Current research on the interference of GNSS (Global Navigation Satellite System) array antennas focuses on the single interference effect and the improvement of interference hardware capability, while the multi-degree-of-freedom (DOF) interference model and mechanism remain to be fully studied. Aiming at this problem, this paper analyzes the preconditions for the definition of anti-jamming degrees of freedom and the characteristics of super-DOF interference through formula derivation and simulation. First, by analyzing the influence of the number of interfering signals on the angular resolution, the prerequisite of the definition of anti-interference degrees of freedom in the airspace is proposed. Second, the definition of anti-interference degrees of freedom is used to calculate the change rule of the critical power of the interference under different numbers of interfering signals. Finally, the influence of super-DOF interference on the array antenna is analyzed. The results show that the prerequisite for the anti-interference freedom of the array antenna is that the distribution interval of the interfering signal is greater than 15°, taking a four-array element uniform circular array antenna as an example. The critical interference power of the array antenna decreases by about 15 dB when the number of interfering signals exceeds the degrees of freedom of the array antenna's interference immunity, provided that the interference resolution is satisfied. The conclusions of this paper give the critical power change rule of multi-DOF interference and the effect of super-DOF interference, as well as the prerequisites for the setting of interference signals, which can be used, for example, in the deployment of distributed interference sources and the development of anti-jamming algorithms.
当前关于全球导航卫星系统（GNSS）阵列天线干扰的研究主要集中在单一干扰效应和干扰硬件能力的提升上，而多自由度（DOF）干扰模型和机制仍有待深入研究。针对这一问题，本文通过公式推导和仿真分析了抗干扰自由度定义的前提条件以及超自由度干扰的特性。首先，通过分析干扰信号数量对角分辨率的影响，提出了空域中抗干扰自由度定义的前提条件。其次，利用抗干扰自由度的定义计算了不同干扰信号数量下干扰临界功率的变化规律。最后，分析了超自由度干扰对阵列天线的影响。结果表明，以四阵元均匀圆形阵列天线为例，阵列天线抗干扰自由度的前提条件是干扰信号的分布间隔大于15°。在满足干扰分辨率的情况下，当干扰信号数量超过阵列天线抗干扰自由度时，阵列天线的临界干扰功率下降约15 dB。本文的结论给出了多自由度干扰的临界功率变化规律和超自由度干扰的影响，以及干扰信号设置的前提条件，可用于例如分布式干扰源的部署和抗干扰算法的开发。
