摘要
针对干扰和多径导致全球导航卫星系统(GNSS)不能精确、安全和可靠地提供位置、速度和时间服务等问题,分析了研制GNSS干扰和多径监测系统的意义,介绍了当前干扰和多径常用的检测方法,设计了一套针对当前四大导航系统(美国GPS、俄罗斯GLONASS、欧盟Galileo和中国BDS)各信号带内以及附近频率的干扰和多径监测系统。系统基于软件无线电(SDR)思想,采用模块化设计,具有良好的功能扩展性和配置灵活性。根据不同干扰的特点,结合实际应用改进了其检测算法:采用能量阈值法检测不同形式的压制式干扰,采用基于捕获多相关峰法判别欺骗式干扰,采取基于最大似然准则的多径估计延迟锁定环(MEDLL)技术估计多径信号的参数。实验结果表明系统能够有效检测各种干扰和多径信号的存在,使用户获取其特征参数,为干扰源的定位、查处、排除、规避以及多径信号的抑制提供决策依据。
The global navigation satellite system（ GNSS） can not provide Position,Velocity,and Time（ PVT） service accurately,safely and reliably due to interference and multipath. For this problem,the significance of developing a GNSS interference and multipath monitoring system is analyzed,followed by the introduction to the currently used interference and multipath detection methods. As the main content, the design and implementation of a GNSS interference and multipath monitoring system is introduced,which is able to mo-nitor interference and multipath signals in the bands of navigation signals of current four major GNSS sys-tems（ i. e. ,GPS,GLONASS,Galileo,and BDS） ,as well as nearby frequency bands. The system based on software-defined radio（ SDR） has preferable flexibility and extensibility by using modular design. Accord-ing to the characteristics of different interferences,the detection algorithms are improved in terms of the de-mand for actual application. Firstly,the principle of energy threshold detection is adopted for the suppres-sion jamming,and corresponding methods are designed for interference with different forms. Secondly,the multi-correlation peaks detection algorithm based on acquisition is used to check the existence of deception jamming signal. Thirdly,the Multipath Estimate Delay Lock Loop（ MEDLL） technique,which is based on the Maximum-Likelihood criterion,is adopted to estimate the parameters of the multipath effects. The ex-perimental results show that the system can detect the existence of various kinds of interference and mul-tipath signals. The characteristic parameters of those signals can be extracted and then provided to the us-ers to facilitate the localization,elimination and avoidance of the interference sources,as well as the sup-pression of the multipath signals.
出处
《电讯技术》
北大核心
2017年第3期288-295,共8页
Telecommunication Engineering
