eLoran噪声误差模型及产生方法研究

增强罗兰(eLoran)系统具备与全球卫星导航系统(GNSS)的互补性，使其成为最佳备份系统. 接收机通过测量到达时间(TOA)进行定时与定位，噪声是影响eLoran信号TOA精度的重要因素，而噪声中高斯白噪声(WGN)又是普遍存在的. 本文首先基于最大似然估计(MLE)方法推导了WGN下的TOA误差模型，其次采用线性同余法与Box-Muller变换对法相结合生成WGN，仿真分析了WGN的时、频域特性，最后利用产生的噪声模拟出TOA测量误差，并与理论TOA模型进行比较. 结果表明:理论误差模型与仿真TOA值误差吻合，验证该研究的TOA测量误差模型和产生噪声的正确性，研究成果可为eLoran信号的TOA误差模型和模拟器中噪声产生提供参考，促进eLoran系统应用发展. 

Reseacher on eLoran noise error model and generation method

The enhanced Loran (eLoran) system is complementary to the Global Navigation Satellite System (GNSS), making it the best backup system. The receiver performs timing and positioning by measuring time of arrival (TOA). Noise is an important factor affecting the TOA accuracy of eLoran signal, and white Gaussian noise (WGN) is ubiquitous in noise. This paper based on the maximum likelihood estimation method was deduced under WGN of TOA error model, then using the method of linear congruence and Box - Muller transform method to generate WGN, the simulation analysis of the time and frequency domain properties of a gaussian white noise, the use of noise simulating TOA measurement error, and comparing with theoretical TOA model, The results show that the theoretical error model is consistent with the simulation TOA value error, which verifies the correctness of the TOA measurement error model and noise generation studied in this paper. The research results of this paper can provide reference for the TOA error model of eLoran signal and noise generation in the simulator, and promote the application development of eLoran system.