Multi-category Interference Suppression For ADS-B Based On A Crossed Array

Automatic Dependent Surveillance-Broadcast(ADS-B) is an aircraft surveillance technology based on the global navigation satellite system(GNSS) and air-ground, air-air data links. It has been widely applied in the field of air traffic management(ATM) and flight tracking owing to high precision and low cost. However, ADS-B is vulnerable to intentional and unintentional interference, which seriously threatens the security of flights. Therefore, this thesis will focus on interference suppression algorithm for ADS-B. The main contents are as follows:Firstly, the thesis summarizes the feature of ADS-B signals, which is the basis of the subsequently proposed interference suppression algorithms. The thesis designs and develops a software receiver for 1090 ES to verify these algorithms. The thesis also provides a deinterleave method with only one channel.Secondly, in the case of jamming, this thesis researches a simple algorithm for detecting jamming based on the different features between ADS-B signals and jamming. In the case of the nonhomogeneous statistical properties of jamming contaminated by ADS-B signals, a Generalized Inner Product(GIP) Non Homogeneity Detector(NHD) is used to exclude the contaminated samples, and the adaptive weights are trained on the remaining samples with the power inversion algorithm to mitigate jamming only and hardly mitigate ADS-B signals. The proposed algorithm is blind adaptive, robust and easy to implement.Thirdly, in the case of spoofing, the thesis proposes a method for recognizing and suppressing spoofing via the comparison between the location broadcast by aircrafts and the crossed array. Without searching over all the space to estimate DOA, the algorithm is low-computation and low-complexity.Finally, in some complex electromagnetic environments with jamming and spoofing existing simultaneously, the thesis provides an algorithm to jointly suppress jamming and spoofing by combining the proposed anti-jamming and anti-spoofing methods. The algorithm can mitigate jamming and recognize spoofing simultaneously.