Study On The Usability Of GPS In The Jamming Environment

GPS can provide precise position, speed and time information in the global area. It plays an extremely important role in both military and civil fields. Along with the development of GPS, it has been exposed that the system is easily jammed. The theses presents the theory, system formation and signal format of GPS. GPS disturbed characteristics are emphasized. It lays a foundation of future work.The characteristics of GPS signal before and after jammed are analysed in consideration of factual measurement results of GPS receiver. The whole anti-jamming system design is presented according to RF and multiple paths. Feasible anti-jamming measures are analysed. Loop filter and space-time adaptive zeroing antenna are emphasized.The theses uses PLL assisted by FLL in loop filter aspect. In adaptive zeroing antenna aspect space-time adaptive array instead of space adaptive array, also minimum power preprocessing algorithm is adopted in the theses. It is indicated by experiments that the design can ensure GPS work normal in jamming circumstance to some extent.