A High-Dynamic Null-Widen GPS Anti-jamming Algorithm Based on Statistical Model of the Changing Interference DOA

Abstract

The directions of arrival (DOA) of interference changes rapidly with time in high-dynamic satellite navigation system, which leads to the mismatch between weights training data and weights applying data during the adaptive processing. In this case, the conventional adaptive anti-jamming algorithms are invalid since jammers may easily move out of the array pattern nulls and could not be suppressed. In this letter, a novel method of null-widen is deduced based on the Laplace distribution model of the changing interference DOA in high-dynamic environment. By taking the moving interferences as discrete interference sources obey the Laplace distribution, the extension matrix can be obtained and the average covariance matrix can be calculated from matrix product to broaden the width of nulls. The new method does not alter the noise contribution to the covariance matrix and does not require information about interference DOA. The width of nulls is easy to control. In addition, by combining with the power minimization approach, the new null-widen method does not need the DOA of desired satellite signal. The proposed method can provide correctly acquisition.