Narrowband Interference Mitigation Techniques: A Survey

The radio frequency (RF) spectrum is a scarce natural resource utilized by terrestrial and satellite systems that operate in regulated frequency bands. The sharing of this scarce resource and the bandwidth of these systems has led to various types of interferences including, narrowband interference (NBI) and wideband interference (WBI). The spectrum congestion problem will only continue to be exacerbated as new applications and technologies are deployed with larger bandwidths to support new user requirements. The handling of NBI in the literature is significant and vast, which deserves recognition in the form of a survey paper. This survey aims to summarize the handful of NBI models and the extent of mitigation techniques that have been reported in the literature over the last decade for various commercial and defense fields which includes terrestrial and satellite systems. More importantly, the source and potential adverse impacts of NBI on different applications and technologies are discussed. A series of mitigation strategies are reviewed including the traditional filter-based methods and recent techniques that utilized machine learning. We strictly limit this survey to time-frequency NBI and ignore the treatment of interference in the spatial domain considering the number of publications reported to date. Lastly, we address some of the identified research gaps and enumerate future research directions to progress NBI mitigation works. This survey provides a brief introduction to the NBI problem and can be applied to future research for emerging applications and technologies.