Software defined radio for GPS

Projecte realitzat en col.laboració amb el centre Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)This project describes the implementation of a software defined radio (SDR) Global Navigation Satellite System (GNSS) receiver completely real-time. The receiver is based on Global Positioning System (GPS) L1 C/A receiver. Also, the project describes the implementation and shows the improvement of a Double Delta Correlator (DDDLL) respect a typical Delay Locked Loop (DLL) of a real-time software defined Global Positioning System (GPS) receiver on a multipath environment.A theoretical analysis of the DLL and DDDLL has been done, and compared their performance over a simulated multipath scenario at radiofrequency. Then the same simulation but in a experimental mode is done with a channel emulator. The double delta correlator exploits the Single Input Multiple Data (SIMD) instructions to achieve real-time performance. The GPS software receiver uses open source libraries including GNURadio, and is capable of running in real-time on standard PC. In another hand, the receiver has been equipped with toolkit positioning system to compute the user position by different algorithms. This is done thanks to the open source GPS toolkit (GPStk). To be able to connect the receiver with the GPStk, a module with a Receiver Independent Exchange Format (RINEX) output has been adde