GNSS接收机的一种快速捕获方法研究  

Study on fast GNSS signal acquisition in GNSS receiver

作　　者：郑伦贵[1] 尤政[1] 张高飞 马林[1] 赵书敏[1] 

机构地区：[1]清华大学精密仪器系,北京100084

出　　处：《仪器仪表学报》2014年第4期807-813,共7页Chinese Journal of Scientific Instrument

基　　金：国家863计划(2013AA122601)资助项目

摘　　要：动态环境中GNSS接收机与GNSS卫星之间的高速径向相对运动导致GNSS信号产生多普勒频移,为适应信号多普勒频移的大范围变化尽快进入跟踪环节,接收机需快速捕获到载波多普勒频移和伪码相位并及时更新环路参数。针对传统捕获方法搜索时间长、捕获困难的问题,基于信号时频域特性提出一种适用大范围多普勒频移、同时实现载波多普勒频率和码相位的快速捕获方法并进一步通过频域相角确定载波精确多普勒频率。仿真结果表明该方法捕获时间为传统捕获的8‰,载波域捕获法的36%,频率分辨率为10 Hz。该方法运算量小、捕获时间短,在保持高检测概率情况下使捕获结果满足后续跟踪环路要求。In highly dynamic environment,the high-speed radial relative motion between GNSS receivers and GNSS satellites causes Doppler frequency shifts of the GNSS signals.In order to adapt the wide range changing of the Doppler frequency shifts,the GNSS receivers must quickly acquire the Doppler frequency shift and CA code phase,and update the loop parameters in time.Aiming at the problems of traditional acquisition methods,such as long searching time and acquisition difficulty,a new acquisition algorithm is proposed based on the signal characteristics in time and frequency domains,which is suitable for wide range changing of the Doppler frequency shifts,and can achieve the fast acquisition of the Doppler frequency shift and CA code phase;the proposed method can achieve the two-dimensional and accurate calculation of Doppler frequency from the signal phase.The analysis and simulation result shows that the acquisition time is 8％ of that of traditional acquisition method and 36％ of that of the carry domain acquisition method;the frequency resolution is 10 Hz.The proposed algorithm has the advantages of less calculation and short acquisition time,which meets the tracking loop requirement of GNSS receivers,while retaining high detection probability.

关 键 词：GNSS接收机 多普勒频移 快速捕获 分辨率 

分 类 号：TN914.42[电子电信—通信与信息系统]