The Processing Arithmetic Research Of Digital Baseband Signals In GPS Receiver

As the new generation of the satellite navigation systems, global positioning system (GPS) has become a widely used system. The sticking point of the application of GPS is its receiver. But the capturing and tracking part is the key part of the receiver design. And it also is the difficulty of the GPS receiver technique. It contains two parts: the pseudo-random noise (PRN) code acquisition and tracking part and the carrier wave tracking part. GPS receiver searching, capturing and tracking the PRN code and demodulating the transmitted navigation message, it is the base of the GPS receiver measuring the GPS signals.This paper is focused on setting up the mathematic model of the corresponding synchronization part to analyze the digital signal disposal arithmetic of the baseband of GPS receiver and measure the characteristic of pseudorange with DDLL etc. It mainly contains the following contents:Firstly It introduces the background of the paper. The corresponding background of the GPS system and the GPS receiver are simply introduced. Also the basic theoretics of Phase-Locked Loop is introduced. Prepare for the following chapters.Secondly the C/A code acquisition arithmetic and tracking method and the arithmetic of the synchronization of the carrier wave in GPS receiver are analysed by setting up the mathematic models. Fast acquiring the C/A code is discussed a certain extent. The measure errors of the 3 degree DLL and PLL are analysed and the results based on the MATLAB are given.Finally a full data operation process of GPS receiver from the simulating production of the digital IF GPS signals to AD sampling data input to the positioning result output is given by the simulation experiment. The design and validation and simulation of the digital signals disposal arithmetic of GPS receiver are finished based on the platform of MATLAB.It is good at improving the process of the digital signal disposal arithmetic of the baseband of GPS receiver that analyzing and discussing the C/A code acquisition arithmetic and tracking method and the arithmetic of the synchronization of the carrier wave in GPS receiver. It is also good at improving the precision of the measurement ofpseudorange and positioning of GPS. Also, it is important to develop GPS receivers and launch into the research of related domain.