The Global Positioning System is available for civil users for two decades, after the United States Government made some of the signals broadcast by the satellites accessible for them, by which outdoor positioning was revolutionized. The commercial GPS receivers hide the signals of the system, only the output coordinates are accessible via the communication port. For az electrical engineer student, it is important to understand the operation of the system, but with these equipments it is not possible to demonstrate it to them, so another method is needed. My task is to design and develop a modular GPS receiver, which makes the the radiofrequency signals necessary for localization accessible. In this thesis, I describe the structure and operation of the GPS, the devices capable of receiving the signals, the elements (amplifier, filter, mixer, A/D converter) of the receiver designed by myself and the functions written in MATLAB with which I try to recognize a signal broadcast by a satellite.