Interference Suppression Based On CMT For High-dynamic GPS

As Global Positioning System(GPS) receiver has been used widely in military affair and economic fields, the problem of GPS signal is easy to be jammed that is becoming increasingly serious. Especially in high-dynamic satellite navigation system, the directions of arrival(DOA) of interference changes rapidly with time and the nulls produced by conventional adaptive anti-jamming algorithms are very narrow, the GPS receiver performance degradation or even can not work since jammers may easily move out of the array pattern nulls and could not be suppressed. For these reasons, it is very important to research the anti-jamming technology for high-dynamic GPS receiver. Adaptive interference suppression algorithms for High dynamic GPS receiver based on the category of covariance matrix taper(CMT) are studied in this thesis.Firstly, this paper analyzes the Mailloux and Zatman null-widen methods, deduces the extension matrix and discusses their applicability based on arbitrary array model. The results show that Mailloux method can be applied to arbitrary array with the interference DOA, and Zatman method is only applicable to linear array.Secondly, a novel power minimization null-widen anti-jamming algorithm is deduced based on the statistical model of the changing interference DOA and the actual receiver motion state in high-dynamic environment, which is analyzed more tally with Laplace distribution. This new method has the following advantages. First, information about the satellite signal DOA and interference DOA are not required; second, the new method is applicable to arbitrary linear or circular array; in addition, the extension matrix does not alter the noise contribution to the covariance matrix and the width of nulls is easy to control.At last, the new method is extended to space-time adaptive processing and the applicability on linear array, circular array and arbitrary array model is proved. Results show that the space-time extension matrix on arbitrary linear or circular array neither needs to know interference DOA nor alter the noise contribution to covariance matrix.Numerical and experimental results certify the effectiveness and practicability of the new method. It has a value of practical application.