全球导航卫星系统矢量载波环的设计与分析  

Design and analysis of global navigation satellite system vector carrier loop

作　　者：陆国生[1] 李立言 赵民建[1] 

机构地区：[1]浙江大学信息与电子工程系,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2015年第1期20-26,共7页Journal of Zhejiang University：Engineering Science

基　　金：中国博士后科学基金资助项目(2012M521172)

摘　　要：为了减弱在传统跟踪算法中不良通道或者解算错误带来的影响,提出自适应载波跟踪算法.算法的基本思想是通过矢量环辅助标量环而不是完全替代标量环实现信号的跟踪.它在每个跟踪通道里添加一个卡尔曼滤波器,该滤波器利用当前鉴频器输出的频率残差与导航处理器反馈的载波频率进行环路更新;根据两者的方差,自动调节通道滤波器的增益因子,保持更加准确的载波估计频率.不同于传统矢量跟踪算法必须在完成导航解算后才更新跟踪环路,改进算法运行在每个跟踪通道上并根据环路积分间隔更新跟踪环路,因此可以在低解算速率的要求下跟踪更大的动态范围.改进算法结合了矢量与标量环路两者的优势,具有矩阵小和数据处理简单的特点.仿真结果表明,该算法较传统算法提高了信号跟踪的准确性和鲁棒性.An adaptive carrier tracking algorithm was proposed in order to reduce the impact from bad channels as well as from solution error in traditional tracking algorithm.The algorithm was based on the idea that vector tracking loop assists scalar loop but not completely replaces of scalar loop.The algorithm added a Kalman filter to each tracking channel,which used the prompt frequency residual by the discriminator and the estimated frequency fed back by navigation processor to update the carrier loop of each channel.Based on their variance,the filter＇s gain factor was automatically tuned to estimate a more accurate frequency.Different from the conventional vector tracking algorithm which updates the loop only after navigation solution,the improved algorithm was running on each channel and updated the loop after correlation and discrimination according to the loop interval.Thus the algorithm can be applied on a more dynamic system but require a lower navigation solution rate.The algorithm combines both advantages of vector loop and scalar loop,and has small matrix to be easily processed.Simulation results show that the algorithm improves the tracking accuracy and robustness compared to conventional algorithms.

关 键 词：软件接收机 矢量跟踪 载波频率跟踪 卡尔曼滤波器 

分 类 号：TN967[电子电信—信号与信息处理]