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 time-frequency domain (TFD) technique. In particular, the proposed approach is based on the use of an adaptive finite impulse response (FIR) 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 IF. In this way, it is possible to largely reduce the distortion induced over the desired signal due to filtering, with respect to simpler notching techniques irrespective of the actual interfering power. In this paper we introduce a new analytical model which accurately characterizes the output signal-to-interference-plus-noise-ratio (SINR) for narrowband sinusoidal interference considering Galileo BOC modulated signals. This is achieved for both three and five coefficients excision filters, for which optimum filter coefficients can be derived to maximize output SINR.