A Novel Ratio-Phase Metric of Signal Quality Monitoring for Real-Time Detection of GPS Interference

Abstract

Through the growing usage of Global Positioning System (GPS) for civilian applications, healthcare of the system has special importance. However, according to the characteristics of the GPS signals, there is a possibility of interferences on GPS signals. Among all distorting factors, spoofing is more deceitful, because the civil receiver is not able to distinguish the counterfeit signal from the genuine signal. In recent years, many efforts have been made to deal with spoofing. We studied recognition of the clear certainty of a spoofed condition in this work, which focuses on Signal Quality Monitoring (SQM) method. In an effort to troubleshoot the previous metrics and methods, we have introduced a new metric for interference detection that investigate both of in-phase and quadrature components of correlation outputs also use parameters associated with the main peak in proper form. As a consequence of simultaneous evaluation of phase and amplitude of GPS signal, the proposed metric is more reliable and average of detection accuracy has increased from 1.3 (related to previous metrics) to 4.8.