Jamming and Spoofing Protection for ADS-B Mode S Receiver Through Array Signal Processing

Abstract : Automatic-dependent surveillance-broadcast (ADS-B) receivers are vulnerable to jamming and spoofing attacks. Air traffic management is expected to heavily rely on ADS-B in the future so it is important to provide protection against these attacks. One promising solution is array signal processing. Jamming signals can be suppressed by beamforming and ADS-B positions can be verified by comparing them to the measured angles of arrival (AoAs). Many studies have been done on this topic but they generally consider either jamming or spoofing. However, in a real environment, anti-jamming and anti-spoofing functions must be provided together. It is important to understand the performance when these two functions are implemented simultaneously in order to guide future research and development strategies and implementation plans. Thus, we conducted an experimental evaluation of anti-jamming and anti-spoofing functions. For jamming protection, a power-inversion beamformer was used to suppress the jamming signal. For spoofing protection, a Capon’s beamformer was used to measure the AoA. The array used was a uniform linear array of four elements. The experiments were conducted in an anechoic chamber using a four-channel oscilloscope and the signal processing was conducted offline. The results of the anti-jamming experiment showed that the jammed signals were successfully recovered and the signal-to-jamming-plus-noise (SJN) ratio was increased to above the decodable level. The effects of various parameters on the overall performance and the lower bound performance were also investigated. Moreover, the anti-spoofing experiment showed that the AoA of the ADS-B signal could be measured successfully. The AoA accuracy was evaluated in terms of the standard deviation, which was further converted into the probability of spoofing detection. These findings will be important in the implementation of effective infrastructure to ensure safe air travel.