Navigation System Of Broadband Interference Technology Research

With the rapid development of satellite navigation technology and its application in advanced military weapons, as well as anti-interference improvements achieved by other countries in their own navigation system, upgrading anti-jamming performance in the satellite navigation system becomes critical. Considering the fact that most current interference signals are wideband signals, this thesis studied how some parameters will influence the anti-jamming performance based on basic interference suppression theories.First of all, satellite navigation signals are spreading code signal, and the power of satellite signal is weaker than that of the noise. Besides, the direction of arrival of the interference is unknown in real environment. So the power inversion algorithm which is a common interference suppression algorithm in satellite navigation was introduced. The derivation of basic parameters in the algorithm and simulation results are carried out to provide guidance in actual situation.In real cases, with the increase of bandwidth, the performance of spatial adaptive filtering worsen acutely. A common and conditional measure to solve this problem is to increase the time delay line taps. It is both simple and effective. To come up with an unconditional measure, the interference convert function is introduced, and detailed description as well as simulation results are also given. Result shows that when tap spacing meets a certain condition, the performance of anti-wideband-interference can be as good as that of anti-narrowband-interference by increasing the number of taps.There are more than ten satellites no matter what the navigation system would be. Take the Beidou navigation system for example, its second-generation contains 32 satellites. After interference suppression, it can positioning and navigation effectively as long as signals from four or more satellites are received accurately. However, the number of interference signals is usually three or less. Therefore it is impossible to judge the array’s performance based on the output SINR. So the interference gain, power inversion structure and time tapped delay line model are introduced. Furthermore, simulations of influence on the performance of interference suppression parameters caused by different parameters are carried out to give a guidance on upgrading antiinterference system in BeiDou.Finally, because the channel of the navigation interference suppression system is not ideal in real situation, the performance of the array will deteriorate in real case. To solve this problem, the wide-bandwidth channel equalization of the array channel was carried out. The equalizer was tested in the anti-interference system of BeiDou navigation system. Simulation based on real data shows that it can better the antiinterference performance deterioration caused by the difference in channels. It also shows that channel equalization can improve the performance of anti-wide-bandwidthinterference in navigation system.