CAJ | 학술논문

现代卫星导航及测控应用对接收机在高动态环境下实现测量通信提出了迫切需求。为了解决大多普勒频偏扩频信号的快速捕获问题，提出了一种在频域并行搜索码相位及多普勒频偏的双频域快速捕获方法。采用双块补零算法将长的相关积分操作分割为多个短的相关积分操作，然后采用快速傅里叶变换进行圆周相关，大大节约了处理时间，利用频域圆周移位与时域载波剥离等价的原理，大幅提高了频率搜索效率。与时域相关算法和单频域计算方法相比，在捕获灵敏度不变的条件下，该方法将计算量减少90％，显著提高了运算速度，适合高动态环境下扩频信号的快速捕获。该方案应用于星载接收机平台FPGA实现，测试结果表明该方案可以在0．1s内完成±500 kHz频偏下扩频信号捕获。
현대위성도항급측공응용대접수궤재고동태배경하실현측량통신제출료박절수구。위료해결대다보륵빈편확빈신호적쾌속포획문제，제출료일충재빈역병행수색마상위급다보륵빈편적쌍빈역쾌속포획방법。채용쌍괴보령산법장장적상관적분조작분할위다개단적상관적분조작，연후채용쾌속부리협변환진행원주상관，대대절약료처리시간，이용빈역원주이위여시역재파박리등개적원리，대폭제고료빈솔수색효솔。여시역상관산법화단빈역계산방법상비，재포획령민도불변적조건하，해방법장계산량감소90％，현저제고료운산속도，괄합고동태배경하확빈신호적쾌속포획。해방안응용우성재접수궤평태FPGA실현，측시결과표명해방안가이재0．1s내완성±500 kHz빈편하확빈신호포획。
In the present satellite navigation applications , the global navigation satellite system ( GNSS) receiver must be able to work well at large dynamic environment .In order to capture rapidly satellite navigation signals at the large frequency deviation , this paper presents an improved Bi-Frequency domain calculation method which could parallel search code phase and Doppler shift .First, long correla-tion integral operation is divided into short correlation integration operation with double block zeros pad-ding ( DBZP) algorithm, quickly searching code phase with circular correlation combined with Fast Fou-rier Transform ( FFT) , significantly reducing the amount of computation .Then the amount of computation is largely reduced with equivalence principle of the frequency domain circular shift and time domain carri -er peeling .Compared with continuous acquisition algorithms and single frequency domain acquisition al -gorithm under the same acquisition sensitivity conditions , operation time reduces 90%.It is suitable for rapid acquisition of GPS signals under large deviation conditions .Experiments show that the method can capture GPS signal ±500kHz within 0.1s.