Research On GPS Navigation Anti-jamming And Assisted Positioning Methods

The global navigation satellite system is not only used in the military field,but also has an irreplaceable role in the civilian applications,such as car navigation,unmanned aerial vehicle transportation and so on.The performance of navigation signal receiver under interference environment directly affects the implementation of position finding and navigation,since GPS(Global Positioning System)signal is susceptible to interference,research on the method of GPS signal anti-jamming has profound implication.The main contents and work are summarized as follows:The principle of GPS and work process of its receiver are firstly analyzed.We briefly introduce the generation process of GPS signal,the realization method of signal acquisition algorithm,and the characteristics of GPS signals.By comparing the performance of traditional capture algorithm in normal and interference environment,we find that the algorithm can capture satellite signal successfully in normal environment,while in interference environment,the efficiency will be reduced.Secondly,anti-interference algorithm is studied for GPS signals in interference environment.The definition and characteristics of non-circular signals are introduced.According to their characteristics,MNCR(Maximum Non-circular and Circular Rate)is a method used in a circumstance when receiving signals are combined with non-circular signals and circular signals.Then GPS anti-jamming algorithm based on MNCR criteria and the solusion process is given.Thirdly,taking into account that the MNCR algorithm has a large amount of computation and does not apply to the high dynamic environment during the application process,the improved MNCR algorithm and nulling widen method are provided.Finally,GSM(Global System for Mobile Communication)assisted positioning method is used to define the GPS position of unmanned aerial vehicle in interference environment.In this method,the device simultaneously uses the GPS signal and the GSM signal to estimate position.When the GPS signal is interfered,thus a direction from receiver to destination can be estimated to continue the flying and finally get rid of the interference area.