Capture Technology And Anti-jamming Performance Of Navigation Receivers

At present, many countries are researching on and enhancing global navigation satellite system (GNSS) of their own. At the same time, the pace of militarization of satellite navigations is in full swing. Due to military application of GNSS produces tremendous threaten to national security, countries all over the word are engaged in the study of Electronic Warfare Technology for navigation systems. Facing increasingly complex electronic environment in the information war, the security problems of satellite navigation systems have become more and more serious. Thus it is in urgent need to improve anti-jamming capability of navigation signal receiver.Firstly the development process of GNSS and the research status and trends of interference suppression techniques for navigation signal receiver were summarized. Then the Capture and tracking algorithms of navigation signal receiver were studied, according to which a simulation platform of acquisition and tracking process of navigation signal receiver was built in Matlab. Finally two sets of anti-jamming scheme of navigation signal receiver were studied and compared based on the simulation platform, and based on which a series of interference simulation and performance analysis were done.The key work and innovations of this thesis mainly include:1. Built the mathematical model and Matlab simulation model of array signals for the anti-jamming navigation receiver in the strong interference environment.2. Studied three search methods for navigation signals capture, combining with project requirements did cost analysis and computer simulation experiments for each algorithm.3. Studied algorithms to calculate capture threshold,analysed and compared the capture probability and the false alarm probability of different algorithms, determined the capture threshold under different signal to noise ratio(SNR) by computer simulation.4. Studied the algorithm to reduce the residual code phase offset and algorithms to search fine frequency of capture process. The validity of each algorithm was verified by computer simulation. 5. Studied the receiver's tracking loop, in particular, focused on the Carrier Tracking Loop. Parameters of Tracking Loop were discussed and performances of different phase algorithms were compared by computer simulation experiments.6. Did simulation about the joint treatment process of signal acquisition and tracking, compared and analyzed the system's performance under interference environment under different disturbance.7. Built simulation platform for anti-jamming navigation signals receiver in Matlab , based on which two anti-jamming schemes were studied. Their anti-interference abilities and the improvement of the signal acquisition performance were compared by a large number of simulation experiments after which analysis and discussion were done.