【作者】 刘莉； 战兴群； 刘卫； 牛满仓；

【Author】 Li LIU,Xingqun ZHAN,Wei LIU,Mancang NIU School of Aeronautics and Astronautics,Shanghai Jiao Tong University,Shanghai,China

【机构】 上海交通大学航空航天学院；

【摘要】 随着GPS、GLONASS、伽利略导航系统和北斗导航系统陆续运行,兼容性议题在国际卫星导航领域成为各国关注的焦点。2010年12月,中国成功地发射了北斗二代系统第七颗导航卫星,该系统将于2020年之前建成为全球导航系统。由于北斗导航系统的信号体制与GPS近似且占用相同的频段,这就不可避免地带来了兼容性问题。本文从理论上分析了兼容性评估的重要参数:频谱分离系数、码跟踪谱灵敏度和等效载噪比衰减,阐述了伪随机码码长、导航数据速率和码片速率对兼容性计算的影响,在综合考虑信号兼容评估的运算速度和准确性的基础上,提出了改进的GNSS兼容性评估模型。并且以此兼容性评估模型对北斗导航系统和GPS所有频段进行了仿真,仿真分析中考虑到了北斗导航系统和GPS的具体频率分配、信号体制、发射功率、发射带宽、卫星天线增益、仰角、多普勒偏移、信号在空间传播的衰耗以及接收机参数。通过仿真可以看出:当北斗导航系统满星座运行时,GPS对北斗系统的干扰将大于北斗系统对GPS的干扰。更多还原

【Abstract】 Compatibility becomes a matter of concern in GNSS field for many countries as multiple systems like GPS,GLONASS,Galileo and Compass are all in service.In December 2010,China launched the seventh Compass PhaseⅡsatellite,and the nation plans to make it provide global service before 2020.Since Compass’s signal structures are similar to and its frequencies are close to GPS,it certainly causes the interference problem. This paper analyzes the important parameters for compatibility which are spectral separation coefficient,code tracking spectral sensitivity coefficient,and effective carrier-power-to-noise density ratio.Meanwhile,the effect of code length,code-chip rate and navigation data rate onto compatibility computation is assessed.Then,a modified compatibility assessment model with good balance of computation efficient and accuracy is suggested.The simulations of Compass and GPS signals on all navigation bands are accomplished.In these simulations,frequency distribution,signal structure definition, transmission power and bandwidth,antenna gain,elevation angle,Doppler offset, atmospheric loss and receiver’s parameters are considered.The result of simulation shows that GPS induces more interference onto Compass than that Compass induces onto GPS when full Compass constellations are deployed in 2020.更多还原