Research On Synchronous Generating GPS Spoofing Technology And USRP Implementation

With the rapid development of technologies such as autonomous driving,Internet of Things,mobile communications and the popularization of mobile terminals in recent years,GPS technology has gradually been integrated into all walks of life,providing great convenience to people's lives.But the strength of GPS signal when it reaches the ground is very weak,it is susceptible to various interferences.The spoofing interference is the most harmful among various interference types.It induces the receiver to produce false positioning by generating a spoofing signal similar to the real GPS signal,which has strong concealment.And nowadays,various software radios have sprung up like bamboo shoots after a rain,greatly increasing the possibility of GPS spoofing.With regard to the research on GPS spoofing,it is currently in the stage of establishing theoretical models at home and abroad.There are few studies on the synchronization of spoofing signals with real GPS signals,and less experiments to verify in real scenarios.In the research of this article,two spoofing methods are analyzed for civilian GPS receivers,and they are verified by theoretical simulations and experiments in real scenarios.The research content of the paper is summarized as follows:1.Introduces the composition of civil GPS signals and the theory of GPS receivers,and specifically analyzes the C/A code generation process and its related characteristics.Improved the traditional capture algorithm and verified by simulation,and the principles of carrier tracking and code tracking are explained in detail and simulated.2.The principles of two generating spoofing are briefly introduced,and for the problem of signal parameter synchronization in the intermediate synchronous generating spoofing,the method of compensating and estimating parameters such as transmission power,carrier frequency and code phase of forged signals is studied.Theoretically analyzes the influence of spoofing signals on the acquisition loop of the target machine.Aiming at the situation of synchronization errors,the influence of different estimation error ranges of carrier frequency and code phase on the tracking loop of the deception target is analyzed,and simulation verification is carried out by setting different parameters.3.Based on the hypothesis that the spoofing signal is synchronized with the real GPS signal,a synchronous traction strategy is proposed and verified by simulation.That is,on the basis of roughly synchronizing the code phase,by increasing the pseudo code rate of the spoofing signal and a certain power,the code phase is gradually advanced and the local code phase is pulled,so as to achieve stable control of the target machine.4.Based on USRP and GNU Radio,an experimental platform for primary generating spoofing and intermediate synchronous generating spoofing was built.The static position spoofing and dynamic trajectory spoofing in the primary generating spoofing and the synchronous traction model in the intermediate synchronous generating spoofing are tested on two platforms.And data analysis is performed on the code phase of the local pseudo code after spoofing,verify the correctness of the synchronous traction strategy.