Research And Implementation Of Channel Simulator In Navigation Countermeasure

With the development of Global Navigation Satellite System(GNSS),the high-precision positioning and navigation performance of GNSS has been widely used in different areas,especially in military fields specifically for UAVs,warships,submarines,cruise missiles and ballistic missiles navigation systems.That is why navigation and defense technologies related to global navigation systems have attracted great attention of many countries.At present,the research on navigation and confrontation technology mainly focuses on the interference of navigation and positioning signals,destroying its positioning and navigation function.This paper concentrates on the research and implementation of channel simulator in forwarding spoofing interference.Based on the current studies and summarization of the new navigation,anti-technology and channel simulation technology,this article analyzes the problems,for instance,the bias theory,the poor practicability.The research specifically focuses on the field of mobile communication,The corresponding channel characteristics of the navigation signal to achieve forwarding spoofing interference.Based on the investigation and analysis of the navigation signal structure,the positioning principle and the influence of channel characteristics on the navigation signal,the interference model of forwarding spoofing interference are established.According to the functional requirements of the channel simulator in the model,a channel simulates the overall realization of the program.The detailed design process of channel simulator implementation of channel simulator,channel simulator signal processing module,and channel simulator control software is provided.Considering the non-linearity of the receiving frequency,the third-order DDS is used to simulate the carrier,Doppler.Moreover,uses the FPGA chip as the signal processing module of the channel simulator,carrying on the Doppler frequency shift and the delay channel characteristic simulation to the IF navigation signal,simultaneously uses the channel simulator control software to carry on the real-time control in the parameter form.Finally,after implementing the overall design of the channel simulator,a performance test was performed to verify the simulation results of the channel.Which includes the output synchronization of different channels,the relative time delay,Doppler frequency offset test and the overall functionality of the channel simulator test.The test results show that the channel simulator can accurately simulate the channel characteristics such asrelative delay and Doppler frequency shift of the navigation signal,and successfully generate the spoofing signal to realize the deception jam.