Opportunistic Jamming for Covert Communications: Ginibre Point Process Modeling and Analysis

We investigate covert communication in wireless networks with spatially distributed friendly jammers that radiate jamming signals to hinder an adversary from detecting the existence of the communication between a transmitter/receiver pair. Each jammer opportunistically broadcasts a jamming signal when the small-scale fading channel to the receiver is less than a threshold to mitigate the interference at the receiver. We model the spatial distribution of the jammers as a β-Ginibre point process that reflects the repulsion among the locations of the jammers. The exact expression of the communication outage probability (COP) at the receiver is identified, and an approximation of the detection error probability (DEP) at the adversary is derived. We also examine the optimization of the opportunistic jamming threshold parameter that maximizes the DEP while satisfying a requirement on the COP.