北斗信号快速捕获研究与仿真  

Research and Simulation of Bei Dou Signal Fast Acquisition

作　　者：李世光[1,2] 毛新凯[1,2] 杨军[1,3,2] 王伟[1,2] 

机构地区：[1]北京无线电计量测试研究所,北京100039 [2]中国航天科工二院,北京100039 [3]计量与校准技术国防科技重点实验室,北京100039

出　　处：《计算机仿真》2015年第4期101-105,共5页Computer Simulation

摘　　要：捕获速度和捕获多普勒误差影响着北斗接收机的工作性能,北斗信号导航电文的高数据率使传统通过加长快速傅里叶变换(FFT)数据长度来精细化多普勒频移估计的方法不再适用。在研究北斗信号结构和并行码相位搜索捕获原理的基础上,利用FFT对北斗信号实现快速捕获,根据信号相关幅值与多普勒频移估计误差的关系,采用曲线拟合对多普勒频移进行精细化估计,提高了北斗信号的捕获性能。利用采集的北斗导航模拟器信号和MATLAB对算法进行了仿真,仿真结果表明,在1ms相干积分时间下,并行码相位搜索捕获算法成功捕获到全部卫星信号,经曲线拟合精细化之后的多普勒频移估计误差小于50Hz。Acquisition speed and acquisition Doppler error affect the working performance of BeiDou receiver. Traditional Doppler frequency shift estimation refinement method by lengthening the data length of FFT cannot be used due to high navigation data rate of BeiDou signal. In the paper, fast acquisition of BeiDou signal based on FFT was realized after studying the structure of BeiDou signal and parallel code phase search acquisition principle. Curve fitting was used to refine the Doppler frequency shift estimation based on the relationship between signal correlation amplitude and estimation error. Thus the acquisition performance was improved. The algorithm was simulated with MATLAB using sampling data of BeiDou navigation signal simulator. The results show that all satellites were acquired successfully under lms coherent integration time and the Doppler frequency shift estimation error is below 50Hz after refinement by curve fitting.

关 键 词：北斗卫星导航系统 快速傅里叶变换 捕获 曲线拟合 

分 类 号：V411.8[航空宇航科学与技术—航空宇航推进理论与工程]