文章基本信息

标题：Galileo Open Service and Weak Signal Acquisition
本地全文：下载
作者：Gérard Lachapelle ; Mark Petovello ; Daniele Borio 等
期刊名称：Inside GNSS
印刷版ISSN：1559-503X
出版年度：2007
卷号：2
期号：8
出版社：Gibbons Media & Research
摘要：How will the Open Service Galileo signal in space change the acquisition process in GNSS receivers? A: The Galileo signal in space (SiS) for the Open Service (OS) essentially differs from the GPS C/A-code by its use of the binary offset carrier (BOC) modulation and the adoption of longer spreading codes. Moreover, two different channels have been allocated for the OS: the data and the pilot channels. The former carries the navigation message whereas the latter is data-free. The pilot channel is characterized by a secondary code that modulates the primary spreading sequence, producing a tiered code with a period of 100 milliseconds. The bit-rate of the data channel is 250 sps (symbols per second) against the 50 sps of the GPS C/A-code. A GNSS receiver can perform acquisition of the pilot and data channels separately, and the results of the two processes can be non-coherently combined in order to exploit the fact that the two signals experience the same code delay and Doppler frequency.