Performance impact of pilot tone randomization to mitigate OFDM jamming attacks

Abstract

Orthogonal Frequency Division Multiplexing (OFDM) uses pilot tones to estimate and equalize the channel's frequency response whose locations and values are known. This makes OFDM prone to pilot tone based jamming attacks. Our previous research analyzed such jamming attacks. This paper builds on this idea and proposes approaches to mitigate the effect by randomizing pilot tone locations. It also presents OFDM channel and equalizer model, formulates channel estimation error, and then undertakes an analysis of OFDM system for randomized pilot tones, verifying through simulation. Both analytics and simulation show that randomized pilot tone schemes perform worse when a jammer is not present but perform better in the presence of pilot tone based jammer. Of the two proposed randomization schemes, the one that constrains the distance between random tones performs better in both scenarios.