CAJ | 학술논문

介绍了一种GPS软件接收机的设计方法.该设计采用软件无线电设计理念,主要包括前端模块、捕获模块、跟踪模块、同步模块、导航解算模块以及其他辅助模块.捕获模块采用基于圆周相关的捕获算法,通过FFT(快速傅立叶变换)分别作用于输入信号和本地码信号将运算变换到频域内处理.该算法可得到C/A码起始相位和分辨率为1 kHz的载波频率信号,但此载波频率精细度差,不能直接用于跟踪环路.为提高载波频率分辨率,采用基于相位关系计算的精频估计算法.实验表明应用精频捕获算法得到的载波精频估计误差在几赫兹以内,可直接用于后续跟踪环路.
개소료일충GPS연건접수궤적설계방법.해설계채용연건무선전설계이념,주요포괄전단모괴、포획모괴、근종모괴、동보모괴、도항해산모괴이급기타보조모괴.포획모괴채용기우원주상관적포획산법,통과FFT(쾌속부립협변환)분별작용우수입신호화본지마신호장운산변환도빈역내처리.해산법가득도C/A마기시상위화분변솔위1 kHz적재파빈솔신호,단차재파빈솔정세도차,불능직접용우근종배로.위제고재파빈솔분변솔,채용기우상위관계계산적정빈고계산법.실험표명응용정빈포획산법득도적재파정빈고계오차재궤혁자이내,가직접용우후속근종배로.
The design of a global positioning system (GPS) software receiver is introduced.This design uses the concept of software radio,and it consists of the following parts:front-end,acquisition,tracking,synchronization,navigation solution and some assisting modules.In the acquisition module,the acquisition algorithm based on circular correlation is utilized.The input data and the local code are converted into the frequency domain by means of the fast Fourier transform(FFT).After performing circular correlation,the initial phase of the C/A code can be obtained and the carrier frequency can be found in 1 kHz frequency resolution,which is too coarse to use for the tracking loop.In order to improve the frequency resolution,the fine frequency estimation through a phase relationship is then achieved,by which,the frequency resolution is improved dramatically.Experiments show that the inaccuracy of the carrier frequency can be estimated within a few hertz by the fine frequency estimation method,and the fine frequency attained can be directly used for the tracking loop.