A new implementation of narrowband interference detection, characterization, and mitigation technique for a software-defined multi-GNSS receiver

Abstract

Due to the very low power of satellite signals when reaching the earth’s surface, global navigation satellite system receivers are vulnerable to various types of radio frequency interference, and, therefore, countermeasures are necessary. In the case of a narrowband interference (NBI), the adaptive notch filtering technique has been extensively investigated. However, the research on the topic has focused on the adaptation of the notch frequen-cy, but not of the notch width. We present a fully adaptive solution to counter NBI. The technique is capable of de-tecting and characterizing any number of narrow inter-fered bands, and then optimizing the mitigation process based on such characterization, namely the estimates of both interference frequency and width. Its full adaptive-ness makes it suitable to cope with the unpredictable and diverse nature of unintentional interfering events. In addi-tion to a thorough performance evaluation of the pro-posed method, which shows its benefits in terms of sig-nal quality improvement, an analysis of the impact of different NBI profiles on GPS L1 C/A and Galileo E1 is also conducted.