Covert Communication with Cognitive Jammer Embedded in Public Communication System

In this work, we investigate covert communication with a cognitive jammer (CJ) embedded in a public communication system. Specifically, while the transmitter continuously transmits public messages to the receiver, it may also transmit its covert messages opportunistically, and a CJ is utilized to assist the covert communication. To evaluate the covert performance, we derive the detection error probability (DEP) for both the CJ and the warden, as well as the average covert rate (ACR). Our analysis indicates that applying a CJ to assist covert communication embedded in a public communication system can outperform the scheme with an uninformed jammer or without a jammer in terms of covertness. A high public transmission rate can degrade the covertness; however, improving the detection accuracy of the CJ can contribute to enhanced performance in terms of both covertness and ACR.