多径条件下GNSS干扰信号测向分布研究

为开展GNSS干扰源定位研究，围绕信号多径传播建立了干扰信号相位的多径衰落模型并提出了测向分布描述方法.首先针对GNSS干扰信号给出了测向模型以及理论误差；其次仿真分析了多径条件下干扰信号相位分布与莱斯因子的关系，通过推导相位分布PDF建立信号相位的数学模型；最后利用蒙特卡洛仿真研究测向分布与莱斯因子和来波方向的关系，并采用置信区间进行数学描述.理论推导和仿真结果表明，当莱斯因子较大时多径条件下的干扰信号相位服从高斯分布，测向结果方差随莱斯因子增加而减小，且来波方向垂直于基线时方差最小，莱斯因子大于20时同一置信水平下的置信区间趋于稳定. 

The Direction Finding Distribution of GNSS Interference on the Condition of Multipath

In order to carry out the research on locating the source of global navigation satellite system (GNSS) interference, a model of multipath fading of the interference phase was built and a method of depicting the direction finding distribution was proposed according to the multipath propagation of the interference. Firstly, direction finding model and its theoretical error were listed aiming at GNSS interference. Then, the relationship between phase distribution and Rician factor was simulated and analyzed on the condition of multipath. By the means of inferring the PDF (probability density function,) of phase, a mathematical model of the phase of GNSS interference was built. Finally, a research on the relationship between direction finding distribution and Rician factor along with DOA was carried out, taking advantage of the Monte Carlo simulation. The theoretical derivation and simulation results indicate that the phase of interference follows Gaussian distribution on the condition of multipath when the Rician factor is pretty large. The variance of direction finding decreases with the increase of Rician factor. The variance is the minimum when the moment DOA is perpendicular to the base line. And the confidence interval tends to stable with the same confidence level while Rician factor is more than 20.