Adaptive Interference Mitigation for Galileo L1 Band Receivers in Time and Frequency Domains

This paper proposes a method for interference mitigation (IM) in the Galileo system based on a joint timefrequency domain (TFD) technique. In particular, the proposed approach is based on the use of an open loop adaptive filter, which introduces a notch in correspondence of the instantaneous frequency (IF) of the jammer. The filter coefficients are adapted to both jammer power and instantaneous frequency (IF). In this way, it is possible to greatly reduce the distortion induced over the desired signal by the filter, with respect to more simple notching techniques irrespective of the actual interfering power. Considering Galileo signals, we apply three and five coefficients excision filters, introducing a new analytical model of the output signal-to-interference-plus-noise-ratio (SINR) and the Galileo navigation message uncoded Bit Error Rate (BER), showing the effects of the presence of BOC modulation.