FPGA-based Research And Implementation Of GPS-bit Frame Synchronization

Global Positioning System(GPS)has many advantages,such as global,a11-weather,high precision and three-dimensional positioning,etc.It is the most advanced satellite navigation and positioning system which is widely used.So it is necessary to research it.By capturing and tracking GPS signals,filtering and sample processing those signals.And to navigation messages of processing is a crucial part.The most important steps for navigation data extraction are bit synchronization and frame synchronization.This paper first introduces the importance of bit frame synchronization in the GPS navigation data of extraction and describes the research background and its significance.Then from the GPS receiver position principle,we briefly introduced the GPS system structure,as well as signal acquisition and tracking methods,and propose two methods of GPS signal acquisition.Then the structure and content of GPS navigation date to be explained and introduced,and mainly describes the navigation date bit synchronization,frame synchronization principle,in which a detailed study to the parity principle,and put forward a simple and practical calibration method.Finally,to achieve frame synchronization of the navigation data in the FPGA platform,which judge to the synchronization of navigation data by using Verilog language program,and analysis the performance of bit frame synchronization system,proposed measures for its protection.