DIGITAL BASEBAND PROCESSOR FOR THE GPS RECEIVER MODELING AND SIMULATIONS

A Global Positioning System (GPS) receiver has been modeled mathematic ally and implemented in software. The digital baseband processor of th e receiver performs the maximum likelihood estimations of the GPS obse rvables. The following issues are discussed: 1) the fundamentals of th e digital GPS receiver, 2) the modeling of the digital baseband proces sor, and 3) the performance of the modeled static and dynamic receiver s. The software-based receiver is more flexible, less expensive and mo re accurate compared with hardware receivers in receiver designs and G PS system performance analysis.