Development of a VC++ Based GPS Software Receiver

The GPS software receiver,which has many merits such as needing little of hardware resource,having strong transportability,costing little money when redesigned,has become the research focus of GPS receiver.Some algorithms of GPS receiver such as the acquiring algorithm based on FFT,the carrier tracking algorithm and code tracking algorithm based on hybrid loops,the extracting algorithm of ephemeris and the principle of calculating pseudorange are simulated.The designed GPS software receiver can output much information,such as the carrier frequency,the code frequency and the pseudorange of channels which is in tracking status,the ephemeris and the status of satellites,the status of receiver.The operating performance of the GPS software receiver is introduced under real digitized intermediate frequency(IF) GPS signals.The results indicate that the positioning accuracy of designed GPS software receiver is within 20 meters.The receiver can realize all functions of the hardware receiver with the input signal of IF GPS data.Updating the algorithms of the GPS receiver is flexible,which provides a convinient and fast simulation platform for furthur researching various algorithms of GPS receiver.