高动态环境下C/A码的捕获策略  

A Scheme for Acquiring C/A Code in High Dynamic Environment

作　　者：葛群芳 谢伟[2] 

机构地区：[1]民航合肥空中交通管制中心,安徽合肥230051 [2]安徽大学电子科学与技术学院,安徽合肥230039

出　　处：《现代电子技术》2007年第17期65-67,共3页Modern Electronics Technique

摘　　要：在GPS中需要用到伪随机码对导航电文进行扩频。如果GPS接收机想要获得导航电文,首先要对接收信号进行解扩,而对伪随机码的捕获又是解扩的关键。民用GPS接收机所要捕获的伪随机码是C/A码,减少对伪随机码的捕获时间是C/A码接收机的一个重要性能指标。在高动态环境下,需要对C/A码的相位和多普勒频移进行二维搜索。提出了一种高动态环境下的C/A码捕获方案,通过理论分析和仿真,证明了该方案有效地缩短了伪随机码的捕获时间,提高了接收机的实时性。In the GPS, Pseudo Random Noise（PRN） code is demanded to spread the spectrum of electricity text which is used in navigation. If a receiver of the GPS wants to get the electricity text, the received signal must be decoded to restore the spectrum of the electricity text firstly, further more, acquisition of the PRN code is a key part in previous process. The PRN code that is acquired by public GPS receivers is Coarse Acquisition （C/A） code. Shortening the time of acquiring PRN code is an important index for C/A code receiver. In high dynamic environment, the phase of C/A code and Doppler Frequency are needed to be searched in two dimensions. This article presents a scheme for acquiring C/A code in high dynamic environment. Analysis in theory and simulation prove that it can shorten the time of acquiring PN code and improves receivers＇real- time ability.

关 键 词：C/A码 高动态 多普勒频移 捕获 

分 类 号：P288.4[天文地球—地图制图学与地理信息工程]