Research On GPS Anti-spoofing Jamming Method Based On Spatial Characteristics

Global Positioning System(GPS)plays an increasingly important role in providing allweather,continuous,real-time,high-precision three-dimensional position,threedimensional velocity and time data for planes,ships and ground forces worldwide in information warfare,as well as providing convenient and easy-to-use positioning and navigation functions for people in daily life.However,with the wide application of GPS,some people attempt to spoof the users to be located by producing or transmitting GPS signals with delay.The wrong positioning results will cause great inconvenience to life and even affect the war situation.For spoofing jamming,it is difficult for the receiver to detect its existence,and how to correctly locate it when spoofing jamming is detected is also an urgent problem to be solved.Therefore,this thesis proposes two anti-spoofing jamming methods based on spatial information characteristics,aiming at completing the positioning work under spoofing jamming.The main works are as follows:(1)A space-time sampling method based on a single stand-alone array antenna is proposed for single-source generation type spoofing jamming.The homologous generated spoofing jamming is distinguished from the difference of wireless channel characteristics contained in real GPS signals.The true and false GPS signals captured by the receiver are separated by relevant processing,and the data of the real signal group is used to complete the positioning in the presence of the spoofing jamming.Since the difference of the channel is reflected in the space domain,single antenna moving sampling is required to utilize this difference,which requires the receiver to be in constant motion,and it is difficult to meet this requirement in many scenarios.The signals are sequentially sampled on the array antenna to simulate single antenna movement,so that the implementation of the method has no limitation on the operating state of the receiver,and the practicality of the method is improved.The simulation shows that the difference between the spoofing signal and the real signal is enough to separate them,and the positioning function can be accurately completed in the presence of spoofing jamming.(2)Aiming at the forward-type spoofing jamming,an anti-spoofing jamming method based on the relative position of the distributed receiver is proposed.The relative position information between a group of distributed receivers is acquired by communicating with each other.Then the receivers use GPS to complete the self-positioning.After interworking the GPS-based positioning results,each receiver uses the result to obtain new relative position information,and finally compares the difference between the two relative position information before and after to determine whether there is spoofing jamming.In the case of spoofing jamming,it is necessary to use the enumeration method to find the receiver affected by the spoofing interference,and the receiver affected by the spoofing interference uses the positioning result of the distributed receiver group not affected by the spoofing interference combined with the relative position information pair to position correctly.Calculations show that the detection probability of spoofing interference exceeds 90% when the number of receivers is sufficient.