Multicarrier Transmission As an Alternative for GPS C/A Code : Simulation and Verification

Abstract

This thesis mainly focuses on using multi-carrier code as an alternative for the C/A code currently transmitted in GPS System. As a substitution, the most critical concern that we have is the Doppler shift, which will Cause the overlap of the sub-carriers transmitted from di erent satellites. The range estimation will be harmed and the positioning failure could be happened at the same time. We introduced two analyses: the probability of collision and probability of position failure between satellites. After that, we work on ensuring the system level performance of our multi-carrier code. To achieve that, we are adding a pseudo random phase on each sub-carrier inside the transmitted signal from each satellite. Theoretical analysis is also provided to assess the performance of our proposed multi-carrier code over code delay and Doppler shift. The result shows that our codes have good performance and is an acceptable alternative to the current GPS signal.