The reduction of continuous wave interference in global positioning system course acquisition signals using adaptive noise cancellation.

摘要

In this thesis, an approach to reducing continuous wave interference in GPS signals is presented. The GPS coarse acquisition signal is a spread spectrum signal that is spread with Gold codes. The properties of the Gold codes used in the GPS signal structure give the signal small out of phase correlations. These small out of phase correlations make adaptive filtering an attractive solution to the continuous wave interference problem.;Adaptive noise cancellation as a solution is discussed and a filter is developed. The implementation of the adaptive noise canceller in it digital intermediate frequency GPS receiver is then presented and simulated using a software signal generator and a software intermediate frequency receiver. The simulation shows that a receiver using adaptive noise cancellation produces acquisitions in jamming scenarios where an unaided receiver either falsely acquires the jammer, or is unable to acquire the GPS signal altogether.