eLoran系统新型信号波形设计及其性能评估  

Design and performance evaluation of new signal waveform in eLoran system

作　　者：李婉清 刘中伟 李实锋[3] 叶清琳 LI Wanqing;LIU Zhongwei;LI Shifeng;YE Qinglin(School of Electronics and Communication Engineering Sun Yat-sen University,Guangzhou 510006,China;School of Information and Communication,National University of Defense Technology,Xi′an 710106,China;National Time Service Center,Chinese Academy of Sciences,Xi′an 710600,China;China Communications Information Technology Group Co.,Ltd,Beijing 100011,China)

机构地区：[1]中山大学电子与通信工程学院,广东广州510006 [2]国防科技大学信息通信学院,陕西西安710106 [3]中国科学院国家授时中心,陕西西安710600 [4]中国交通信息科技集团有限公司,北京100011

出　　处：《全球定位系统》2020年第2期13-20,共8页Gnss World of China

基　　金：国家自然科学基金(61973328);国家重点研发计划重点专项(2018YFB0505200)。

摘　　要：增强型罗兰导航系统(eLoran)作为全球卫星导航系统(GNSS)的备份系统,是国家定位导航授时(PNT)安全的重要基础设施.针对目前标准eLoran信号存在易受交叉干扰、天波干扰,通信数据传输速率低等的问题,本文基于标准罗兰信号体制提出了两种波形改进方法(衰减函数法与对称波形法)并对新型波形进行性能评估.实验结果表明,两种方法能够有效缩短波形持续时间,加速后沿波形下降,减小发射机功耗.对称波形法能够大幅减小波形持续时间,但缩短波形持续时间也将改变原信号波形的频谱特性,利用衰减函数法可以最大程度保证信号的频谱性能.综合分析可知,新型波形能够有效利用时域资源,空余的时间可用于增加传输信号,进而提高数据调制技术的性能.As a backup system of satellite navigation system,the enhanced Loran navigation system is a vital development strategy for national PNT(Positioning,Navigation,Timing).At present,the signal of eLoran are vulnerable to cross interference and sky-wave interference,and the rate of transmitting data is low.Therefore we proposed two waveform improvement methods(attenuation-function-method and symmetric-waveform-method)and evaluated the performance of them based on standard Loran signal system.Experimental results show that the two methods can effectively shorten the duration of the waveform,accelerate the decline of the waveform,and reduce the signal transmitting power.The symmetrical-waveform-method can greatly reduce the duration of waveform,but this method will significantly change the spectrum characteristics of the original signal waveform.By contrast,the attenuation-function-method can ensure the spectrum performance of the signal to the greatest extent.Through comprehensive analysis,we think that the new waveform can effectively utilize time domain resources,which can spare time for extra signal transmitting and consequently raise the efficiency of data modulation.

关 键 词：增强罗兰导航系统 信号体制 波形设计 性能评估 频谱分析 

分 类 号：P228.4[天文地球—大地测量学与测量工程]