Subspace Array Processing for Interference Mitigation in L1-Band Galileo Receivers

In this paper we address the problem of interference mitigation (IM) for the Galileo system. In particular, a IM technique that jointly exploits space, time, and frequency (STF) domains is investigated, extending the approach presented for conventional BPSK DS-SS systems to the representative Galileo L1-band scenario. The proposed technique attempts to remove the undesired signal by projecting the received signal into the subspace orthogonal to the interference subspace, which is designed based on the estimation of the interference signature in space, time, and frequency. The robustness of the proposed technique against practical estimation errors, which can affect both interfering angle of arrival and instantaneous frequency, is investigated in detail in the paper, proving the validity of the technique in realistic scenarios and showing interesting trade-offs