基于信号体制的热噪声模型及对RAIM的影响

Signal structure based thermal noise model and its influence on RAIM

针对因信号体制因素带来的传统加权模型偏差问题,通过分析几种典型信号结构在接收机码跟踪环路跟踪精度上的差异性,提出基于信号体制的接收机伪距误差热噪声模型,推导各频点测距加权因子的产生方式.结合传统双频组合噪声方差估计,探讨新模型对加权接收机自主完好性监测(RAIM)性能及定位估计精度的影响.仿真测试表明,采用该模型能够优化提升RAIM故障检测率,提升各频点测距置信度水平,有效地保证定位精度.

A receiver thermal noise model based on signal structures for code tracking errors was proposed by analyzing the code tracking accuracy diversity for several typical signal structures in delay‐locked loop of receivers in order to eliminate the bias due to the signal structures in traditional weighted model .The formulas of calculated weighted values were derived .With the noise variance estimate of traditional dual‐frequency model ,the influence of the novel model on both performance of weighted receiver autonomous integrity monitoring （RAIM ） and positioning solution accuracy was explored .Simulation results show that the proposed model can promote fault detection rate ,obtain the improved confidence and guarantee the positioning accuracy .