Research And Implementation Of Software Receiver Of New Signals Of Satellite Navigation System

With the continuous development of navigation technology,people are increasingly relying on the services provided by satellite navigation systems,and major countries and economies in the world have begun to develop their own global navigation satellite system.In order to meet people's requirements for the accuracy and reliability of navigation and positioning,and to avoid frequency band interference between navigation systems,new system signals represented by BOC family signals and high-spreading code rate BPSK signals have been used in the new generation of navigation system.At the same time,due to the characteristics of more universal,portable,more flexible and easier to upgrade,there are more and more research on satellite navigation software receiver.The main content of this paper is a software receiver which can process the new system signals(including GPS L1 C,Galileo E1/E5 and BDS B1C/B2a).This paper introduces the structure and characteristics of the new system signal.First introduced the various modulation methods used by them,including BPSK,BOC,TMBOC,QMBOC,CBOC and AltBOC;then introduced the structure of the message,and introduced the encoding scheme,including CRC Code,BCH code,FEC convolutional code,binary LDPC code and base-64 LDPC code;the spatial coordinate system adopted by them is introduced later.The software receiver in this project is divided into two parts: signal processing and user interface.The signal processing part includes various modules of "acquisitiontracking-synchronization-decoding-pseudo range measurement-positioning solution".The function of each module is introduced.At the same time,in each module,the appropriate algorithm is adopted according to the different structure and characteristics of various signals.Through the research on the phase-locked loop filter,this paper determines the value range of various signal loop bandwidths;through the research on the frequency search of the capture module,this paper proposes to obtain more accurate signal Doppler value through precise acquisition.In this paper,each module of the signal processing part of the software receiver is realized by software,and the serial processing of each channel is used to realize the parallel processing of the actual receiver.At the same time,the realization flow chart of each module and the overall flow chart of the signal processing part are given.Finally,this paper completes the design of the user interface of the software receiver,so that the software receiver can display the capture results,tracking output,and positioning results.Using simulation satellite signal data to test the software receiver shows that the software receiver has higher positioning accuracy for the new system satellite signals.