Synchronous Satellite Positioning System Master Station To The Receiving Terminal Development

A geosynchronous orbit (GEO) satellites positioning System in China intends to utilize some geosynchronous orbit (GEO)communication satellites and some inclined geosynchronous orbit(IGSO)satellites to make up the constelation.The signals of navigation and atom clock from ground control station are transmitted by transponders on satellites for the navigation and positioning of users.Compared to the positioning system using special navigation satellites,the expenditure of the system will be relatively less.Especially,the system does not use space-borne atomic clocks.This avoids the difficulties in the manufacture and maintenance of the costly space-borne atomic clocks,and reduces the influence of the relativity effect on the precision of navigation and positioning as well,so the system is characterized relatively by a short construction period .The system is a novel satellite navigation system,which is based on the principle that the land control station transmits the navigation signals via communication satellites(other than special navigation satellites)to the receiver,in which the received signals are processed to obtain its detailed positioning information.Compared with GPS and GLONASS,the reference base point of the system is a virtual point.and the real base point is at the land-based control station.The greatest predominance of the system lies in its low cost of development,operation and maintenance while relatively high positioning precision.The design of the terminal for receiver is introduced in this dissertation. Some basic theories of digital and spread-spectrum communication about the design are described; The signal format of the system is analysed particularly, including the frequency of carrier wave, the type of PN-code, the modulate of BOC, etc;the paper discussed a design about universal digital signal process hardware. In this design, the methods of digital signal process such as the digital costas loop, PN code loop, and digital resample are used.A doable scheme for design the equipment and cells is introduced, and some key specifications are analysed emphatically. At last, some results of testing are enumerated.Finally, the author makes a summary, then offers some designed methods and experiences which can be consulted by others in engineering fields.