Direction Finding under Mutual Coupling and Barometer-based 3D Localization Algorithm for Jamming Signal Detection

Abstract

A jamming signal is an attack technique in which a stronger power signal is transmitted to a satellite navigation signal band so that the receiver cannot receive the satellite navigation signal correctly. Besides, micorning is method that storing and retransmitting a satellite signal, and spoofing is method that giving a false signal by mimicking of a satellite navigation signal. Among them, jamming is most widely used because it can be made easily at a lower price. In recent years, autonomous driving technology of unmanned vehicles such as cars and drones has been developed along the standardization and commercialization of 5G communication technology. In order to implement high-performance, high-precision autonomous driving, it is important to obtain the position information of an unmanned vehicle in real time. An outdoor environment, satellite navigation signals are used mainly for positioning. However, if there is a signal interference such as a malicious jamming signal, a problem occurs that autonomous driving can not be performed properly because the position information can not be obtained properly. Therefore, various anti-jamming techniques have been researched to solve the problem. Array antenna is a technique of forming an antenna pattern in a desired direction by using two or more antennas. When incident angles of the jamming signals are estimated through angle of arrival estimation algorithm, the arrival angle estimation performance is degraded when there is mutual coupling between the antennas. We proposed a modified spherical cap antenna array that minimizes the influence of mutual coupling through compensation algorithm. We show that it is possible to avoid jamming signal to form a nulling at direction of jamming signal and form a beam at direction of the satellite navigation signal through LCMV beamforming. Signal source localization technique is applicable to various wireless communication fields as well as the position estimation of the jamming signal source. In this thesis, we have dealt with three dimensional coordinate localization technology using Wi-Fi signal generated from a portable device of buried person in a disaster situation. We have dealt with three dimensional coordinate localization technique using least square method and show that it is possible to improve localization performance by altitude estimation using barometer information.