GPS Solutions

Spoofing in the form of transmitting fake GNSS signals is a deliberate attack that aims to mislead GNSS receivers into generating false position/time solutions. Current work on GNSS spoofing has mainly focused on spoofing detection where the proposed algorithms only indicate the presence of spoofing attacks. A new architecture consisting of spoofing detection, authentic/spoofing signal classification and spoofing cancelation known as spoofing detection, classification and cancelation for moving GNSS receivers is proposed. Predespreading and acquisition level analysis are performed to detect the presence of spoofing interference. The receiver motion is then used to classify the signals tracked into two groups, namely spoofing and authentic signal sets. A successive spoofing cancelation method is then developed to remove the spoofing signals from the raw digitized samples. It is shown that canceling out the spoofing signals removes multiple access interference and significantly improves the authentic signals’ detectability and tracking performance. Finally, after spoofing cancelation, authentic signals are acquired and tracked and their corresponding measurements are passed to a PVT engine for a reliable position solution. The proposed receiver architecture is analyzed in the acquisition, tracking and positioning layers.