Design And Implementation Of Software GPS Receiver Teaching And Developing Assistant System

The modern standard GPS receivers are commonly based on ASICs for signal processing. While the algorithms for signal processing is black box to the learner. This thesis presents solution for GPS principle teaching by using software radio concept. The main purpose of using software radio concept is to provide a clearer idea of signal processing acquisition and tracking. The software approach should provide better understanding of receiver because the algorithms are based on Matlab program. Once the software concept is well understood, the students should be able to introduce new solutions to problems such as various acquisition and tracking methods to improve efficiency and performances.The software approach is very flexible. It can process data collected from various type of hardware. A program can be used to process signals digitized by different RF-front end with different sampling frequency. It can be used to test the performance of RF-front end. Additionally, a GPS software receiver is more flexible when it comes to adapting the entire receiver to work on the near future Galileo signals. Therefore a software approach can almost be considered as hardware independent. New algorithms can easily be developed without changing the design of hardware. For example in order to study the anti jamming problem one can collect a set of digitized signal with jamming signals and use different algorithms to analyze it.The purpose of our project is to provide an easy-to-use system for collecting GPS signals. To achieve this goal, USB 2.0 peripheral is used which provides plug and play function and support a speed of 480 Mbps. This system has been used for GPS development by graduate student.The major part of this thesis was concentrated on expatiation and comparison of the algorithms of GPS signal searching, acquisition, tracking and navigation solution in GPS receiver. Searching, acquisition, tracking of GPS signal is also discussed in detail in term of software approach.Finally, this thesis analyzed the whole system, introduces main functions-units, illustrate the general flow of development of software receiver.