Interference Mitigation in GNSS Receivers by a Time-Frequency Approach

Undesired interfering signals are considered to be one of the main threats to the correct behavior of new Global Navigation Satellite System (GNSS) receivers. There is a huge variety of interference that can occur in the real world, such as narrow band, wide band, impulsive, stationary, or nonstationary CWs. Processing techniques based on time-frequency (TF) distributions allow one to detect and mitigate many different types of these undesired signals. A TF mitigation technique is proposed to enable GNSS receivers to reduce the interference affecting the incoming signal. The proposed algorithm uses a synthesis technique based on the orthogonal-like Gabor expansion, in order to obtain an estimate of the interference, that is then subtracted from the input signal. In the presence of a wide class of deterministic interfering signals, the proposed mitigation strategy is effective in terms of acquisition and tracking performance and outperforms other algorithms described in the literature.