Covert communication with noise and channel uncertainties

Covert communication is critical to guarantee a strong security and secure user privacy. In this work, we consider adversary's noise and channel uncertainties and analyze their impact on adversary's optimum detection performance and the throughput of covert messages. We determine the throughput of covert messages and its gain and loss by having adversary's channel uncertainty and fading channel, respectively. The results show that fading is essential to hide information, particularly for low noise uncertainty or at high SNR. The improvement of adversary's optimum detection performance, hence the covert throughput, under channel uncertainty is more significant for larger noise uncertainty. The covert throughput is gained by having channel uncertainty roughly 12-19% when the noise uncertainty is about 1-2 dB.