Effect and mitigation of narrowband interference on Galileo E1 signal acquisition and tracking accuracy

The aim of this paper is to present an interference impact assessment in the context of Global Navigation Satellite systems (GNSS), focusing on the new modulation based on the Multiple Binary Offset Carrier (MBOC) scheme that will be used for Galileo E1 civil signal. Simulation results are presented and discussed in order to perform the analysis of Galileo E1 civil signal in presence of Continuous Wave Interference (CWI). The performance of one existing narrowband interference mitigation technique based on Fast Fourier Transform (FFT) is also analyzed in this paper. All the analysis has been done with the help of a Galileo E1 signal Simulink simulator. The results are discussed according to the frequency and power of the CWI in terms of acquisition detection probability, Root Mean Square Error (RMSE) of code tracking and the estimated Carrier to Noise density Ratio (C/N₀). The simulation results show that the CWI with high power degrades most the receiver performance when the interference is at a mid-way between the carrier and one chip rate f_c away from the carrier, which are the peaks of the main power spectral lobes. The interference at f_c away from the carrier has little effect on code tracking. The analyzed FFT technique is a powerful method in CWI mitigation, but it slightly distorts the desired signal.