GPS RECEIVER IMPLEMENTATION USING SIMULINK

Abstract

The Global Positioning System (GPS) is a space- based satellite navigation system that provides location and time information in all weather conditions, anywhere on or near the Earth where there is an unobstructed line of sight to four or more GPS satellites. GPS (Global Positioning System) is the one of the most pre-dominantly used in most parts of the world In the past, the implementation of a complete GPS receiver was divided into two parts. The first part is implemented on ASIC or FPGA. This part includes the acquisition and tracking phases, where the algorithms of the both are written by the HDL programming language. The second part is the navigation solution part that is implemented on DSP by writing its algorithm by C/C++, FORTRAN, or assembly. This means that we have to deal with three environments to implement a complete GPS receiver. The three environments are the Simulation, FPGA, and DSP environments. Moreover, using a text programming languages in writing such long and complicated algorithms makes the process difficult to debug, modify. Simulink was used in the implementation of such receiver; there by introducing a new look for the technology that can be implemented through a graphical user interface environment. This makes every part in the receiver architecture very clear and easier to understand, follow, modify and debug. This can be considered a step added on the route of an open source GPS receiver. Using the same environment in both the simulation and implementation stages makes the designer's mind dedicated most of the time in developing and enhancing the algorithm through rapid prototyping and experimentation and less time on the coding. In general, this article can be considered as introducing a new look for designing, simulating, and implementing the typical GPS receiver using a graphical programming language, which is SIMULINK.