Anti-jamming Satellite Navigation Receiver Frequency Algorithm,

With the wide application of the GPS system in many fields, researchers pay more and more attention to the jamming and anti-jamming of the GPS system. The GPS system based on the spread spectrum theory has some ability to suppress the jamming. Because the GPS signals received is very weak, GPS satellite signals are vulnerable to malicious man-made interference. It is very important to research the way to suppress the jamming. The paper is focus on this problem.People are interested in the methods of anti-jamming in GPS system all the time by space domain, time domain and transform domain. This paper's object is to suppress narrow interference, nonlinearity non-stationary interference using Wavelet Package theory. Considering the character of wavelet, such as microscrope character, we can decompose the GPS signals added interference into a lot of subbands. Then we analyse every subband and if the coeffience of a subband is over the threshold, we think that the subband is polluted and cut it. After this we turn the subbands into the GPS signals by wavelet package inverse transform.At first, we introduce the GPS system, several types of interferences and how we estimate the affect of the interference added into the GPS signals in this paper. Then we discuss the wavelet package theory and the application in interference suppression field. We will get a certain threshold after some complex analys. When all these have been done, we define some parameters and rebuild a Monte Caro model to stimulate the influence that the interferences given the GPS signals.We add the anti-jamming module into this GPS model. Through this model we change our interferences such as Continuous Wave, Multi-ContinuousWave, Narrow Band Interference and Linear Frequency Modulate interference and we get the BER figures. Through the result we prove the efficience of Wavelet Packge in interference suppression.