摘要
介绍和详细分析了GPS和Galileo的空间信号。将Galileo空间信号结构及特性与GPS进行了比较,对接收机接收天线接收的射频信号进行下变频并予以分析。为避免信号混叠,仿真中先采用带通滤波器对射频信号进行滤波,然后采用过采样(过采样因子等于8)进行下变频处理。GPS和Galileo信号通过功率归一化加上高斯白噪声产生。对GPS采用的C/A码和Galileo采用的BOC(1,1)码进行比较,发现后者的中心波峰较窄,尽管这一特点使接收机的跟踪处理更为复杂,但提供了较好的接收性能,尤其在多路效应情况下也更为有效。仿真结果为GPS/Galileo双频软件接收机捕获和跟踪算法设计提供了很好的理论基础。
The space signals of GPS and Galileo were introduced and analysed. Galileo signal structure and properties were presented compared with GPS signals. Down-conversion processing of the radio-frequency signal received by the antenna was made and analysed. The signal is down-converted through digital decimation （over-sampling factor is equal to eight） of a properly filtered signal to avoid aliasing between replicas in simulation. The GPS arid Galileo signals are generated through power normalizing and white Gaussian noise （AWGN）. A comparison between C/A code and BOC（I, 1） code was provided, and the central peak was narrower in the second case. This feature can provide better performance; and BOC（n, m） is more efficient in the multi-path case, although a higher complexity for tracking process was needed. The simulation results provide important theoretical foundation for the acquisition and tracking of GPS/Galileo duel-frequency software receiver.
出处
《中国惯性技术学报》
EI
CSCD
2007年第6期653-657,共5页
Journal of Chinese Inertial Technology
基金
教育部新世纪人才支持计划(NCET-06-0462)
船舶支撑技术基金项目(6922001029)
