Multi-type Interference Suppression for GNSS Based on Despread-respread Method

Lu Wang, Renbiao Wu, Yaotian Zhang, Wenyi Wang and Dan Lu

Peer Reviewed

Abstract:	Spoofing is a serious threat because this kind of interference can misdirect GNSS receivers toward generating falsified position and timing solutions without being aware. Recently, several anti-spoofing techniques have been introduced in the open literature. However, these methods focus on spoofing interference, and do not discuss the case in which jamming and spoofing exist simultaneously. We provide a multi-type interference suppression algorithm based on despread-respread technique, which can mitigate jamming, and two main categories of spoofing. In this method, the signal samples collected by an antenna array are firstly projected into the orthogonal jammer’s subspace so that the strong jamming can be removed. Then, using the acquisition information of a single channel, the despread-respread weighting vectors of all the authentic and spurious satellites can be calculated, which are equivalent with the corresponding array steering vectors of each emitting source. Based on the assumption that every spoofing source transmits several spurious pseudo random noise (PRN) signals in the same direction by a single antenna but the authentic signals are emitted from different satellites and difference directions, spoofing can be detected by means of evaluating the correlation between the despread-respread weighting vectors and mitigated by array process techniques. For maximizing the output of each authentic signal, the despread-respread weighting vectors of the authentic satellites are utilized respectively to form multiple beams so as to achieve the signal processing gain for each authentic satellite. Simulation results show that multiple beams with high gain can be produced by the proposed algorithm, which point on the angle of arrival (AOA) of every authentic satellite and form nulls in AOAs of jamming and spoofing. In our method, the digital beamforming is not depended on the prior knowledge of satellites’ directions. Furthermore, the interference suppression performance is not sensitive to the array manifold errors and the spoofing power.
Published in:	Proceedings of the 28th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2015) September 14 - 18, 2015 Tampa Convention Center Tampa, Florida
Pages:	3405 - 3414
Cite this article:	Wang, Lu, Wu, Renbiao, Zhang, Yaotian, Wang, Wenyi, Lu, Dan, "Multi-type Interference Suppression for GNSS Based on Despread-respread Method," Proceedings of the 28th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2015), Tampa, Florida, September 2015, pp. 3405-3414.
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