Research on BDS (Beidou System) tracking loop for high earth orbit receiver is presented in this paper to overcome the existing problem that the receiver in high earth orbit needs to process signals from the opposite side from the earth,resulting in receiving signals but in lower power,larger Doppler shift and Doppler shift variation.Characteristics of HEO (Highly Elliptical Orbit) orbit navigation signals is analyzed by establishing a simulation environment with STK (Satellite Toolkit) and redesigning of weak signal tracking loop structure and the corresponding tracking process using the simulation results.Sliding correlation method is proposed to increase the integration time of pre-detection to solve NH (Neumann-Hoffman) coding problem in tracking of BDS B1I.Simulation indicates that the integration time of pre-detection is extended to 20 ms by canceling NH code with sliding correlation method after 1 ms stable tracking.The tracking loop is capable of tracking low signal-to-noise ratio BDS B1I signals of C/N0 =26 dBHz in high earth orbit environment to meet requirements for navigation application.%针对高轨接收机需要接收来自地球对面的导航卫星信号而导致接收功率过低,且存在较大多普勒频移和多普勒频移变化率的问题,对适用于高轨导航接收机的BDS(“北斗”系统)信号跟踪技术进行研究.通过STK(卫星开发工具包)建立仿真场景对HEO(大椭圆轨道)接收导航信号特性分析,根据仿真指标重新设计了弱信号跟踪环路结构以及对应的跟踪流程,并特别针对BDS B1I跟踪中存在的NH (Neumann-Hoffman)编码问题,提出滑动相关法去除NH码的方式,来延长预检积分时间.仿真表明,通过1 ms稳定跟踪之后,采用滑动相关法去除NH码,将环路预检积分时间延长至20 ms,跟踪环路能够成功跟踪高轨环境下C/N0=26 dBHz的低信噪比BDS B1I信号,满足导航应用需求.
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