基于预存查表的GPS软件接收机的载波产生方法  

A Method of Generating Carrier for GPS Software Receiver Based on Pre-stored and Look-up Table

作　　者：刘银锋[1] 陈小惠[1] 杨凤伟[1] 

机构地区：[1]南京邮电大学自动化学院,南京210003

出　　处：《舰船电子工程》2011年第3期78-80,125,共4页Ship Electronic Engineering

基　　金：国家科技支撑计划项目(编号:2008BAJ11B01)资助

摘　　要：在GPS软件接收机的跟踪环路,本地码产生、载波产生、相关积分这三个耗时最多的部分中,本地微调生成载波最为耗时,所用时间占整个信号跟踪处理时间的近一半[1]。为了能提高卫星跟踪速度,快速、准确地提取导航数据,达到软件接收机实时性的要求,在对传统GPS软件接收机跟踪算法分析、研究的基础上,提出一种基于载波的二进制存储,通过查表调用解决GPS软件接收机跟踪信号时间中耗时的载波的产生问题的方法。采用预存微调的本地载波二进制数据的方法,可以直接载入载波数据然后查表调用这些数据,免去了每次跟踪循环中产生微调的载波所耗费的时间,成功消除跟踪环路中载波产生的时间,使跟踪的速度提高了一倍。通过用GPS实测数据进行实验,对这种方法进行了验证并对实际的运行结果和性能做了分析,实验结果表明,在保证跟踪性能不降低的前提下,采用预存查表的方法能够有效消除载波产生耗时较多的问题,可以快速准确的实现了对GPS信号的跟踪。提出的这种预存查表的算法作为一种新的产生载波优化方法,在GPS软件接收机实时性方面有着较好的参考价值。In the GPS software receiver tracking loop,the local code generation,the local carrier generation,and the correlation integral is the three most time-consuming part,and the local fine-tune the generated carrier is especially prominent,which take up nearly half of the total signal processing time.In order to extract the navigation data fast and accurately,and achieve the requirements of real-time software receiver,based on the study and analysis of traditional GPS software receiver tracking algorithm,this paper presents a pre-stored carrier method,which solve the problem of the time-consuming local carrier generation for the GPS software receiver tracking loop.Use of pre-stored and fine-tuning of the local carrier method,we can directly load-carrier data then look-up table to transferred the data,eliminate the time-consuming of carrier generation in each cycle and make processing faster than doubled.By using the real GPS measurement data for experiment to validate this method and analyze the actual results and performance of the operation,experimental results show that use the pre-stored look-up table method can effectively eliminate the time-consuming problem of carrier generate and fast and accurate tracking of GPS signals under the premise of without reducing the tracking performance.As a new generation carrier optimization method,this proposed algorithm has good reference value in real-time GPS software receiver.

关 键 词：GPS 预存载波 软件接收机 载波跟踪 实时性 

分 类 号：P228.4[天文地球—大地测量学与测量工程]