Research NS210-B Beidou Satellite Navigation System Signal Based On B1

Beidou satellite navigation system referred to as BDS, it’s a new generation of satellite navigation system developed and constructed in China. BDS, GPS, GLONASS, Galileo are known as the four major global satellite navigation system which are the common focus of the world. Nomatter in the field of national economy or military fields, the Beidou satellite navigation system will play a very important role and show great value. Relative to the space section and the control section,the user section has better scalability in function, high flexibility in design in the whole system. Therefore, more and more people are enjoying to researching satellite receiver.B1frequency channel of beidou satellite navigation system contains the civil frequency channel,so it is very importent to study the signal of B1frequency channel. In this paper, we study the process of satellite signal receiver from the received signal to the user position,by taking the signal of MEO/IGSO satellite as an example. This paper introduces and analysis some important parts of satellite signal processing with the help of the Matlab software. Firstly, three acquisition methods are investigated, then propose the parallel code phase search method with4ms data length as the way to acquisit the satellite signal. We select the4ms data length in order to capture both capture efficiency and reliability. In this paper, based on the Beidou satellite D1navigation message of its own characteristics, discussed and completed the decoding of NH codes. After analysing the structure of D1navigation message,this paper researched the BCH error correction coding and the application in the system carefully. Then found its error correcting capacity is1bit; when the error is greater than1bit, the error correction process is invalid.In the end,process the NS210-B IF signal by the introduced method,and calculate the satellite ephemeris parameters.After verification,all the ephemeris parameters are in the correct range and the distance from No.14satellite to the ground is about21160km,which according the characteristics of MEO satellite orbit.So the principles and methods this paper introduced is correct.Then researching the positioning of Beidou satellite navigation system by taking the single point positioning method for example. An improved method based on the single point is proposed, only need to know the satellite to the receiver antenna relative pseudorange and satellite coordinates to calculate the position of user,instead of the absolute pseudorange when we calculate the location of the user.