Queue-Battery Markov Modeling for Covert UAV Communication with Solar and RF Energy Harvesting over Nakagami- Fading

This paper investigates covert communication for an unmanned aerial vehicle (UAV) operating over a Nakagami- fading channel in the presence of a single ground eavesdropper. The UAV is equipped with a finite-capacity battery and harvests energy from both solar and radio-frequency (RF) sources to sustain long-term operation. During each slot, the UAV transmits data to a ground control station (GCS) while simultaneously emitting jamming signals toward the eavesdropper in order to reduce its probability of detection. We first develop a detailed physical-layer analysis of the eavesdropper’s detection probability over Nakagami- fading for both the data and jamming channels. We then model the joint evolution of the data queue and the battery as a two-dimensional Markov chain. Using the stationary distribution of this chain, we derive closed-form expressions for the long-term throughput, battery-outage probability, and average detection probability. Throughout the paper, the mathematical derivations are presented in a step-by-step and transparent manner so that the framework is accessible to readers who are new to covert communication and queue–battery models with energy harvesting.