Time-Frequency-Power Adaptive Interference Mitigation for Galileo L1 Band Receivers

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 distorsion induced over the desired signal due to filtering, with respect to more simple notching techniques irrespective of the actual interfering power. Considering Galileo BOC modulated signals, we apply three and five coefficients excision filters, introducing a new analytical model of the output signal-to-interference-plus-noise-ratio (SINR) for narrow band sinusoidal interference, and deriving the optimum filter coefficients maximizing this expression.