Covert Communication in Underlay Cognitive Radio Networks with Energy Harvesting

This paper examines covert communication in underlay cognitive radio networks (CRNs) with energy harvesting (EH), in which considers two scenarios: 1) with perfect channel state information (CSI) of the link from the secondary source (SS) to the primary receiver (PR) at Willie, 2) with statistical CSI of the SS-PR link at Willie. The closed-form expressions for Willie’s detection error probability, the average minimum detection error probability, the transmission outage probability, and the maximum effective covert rate under both cases are derived and analyzed. The maximum effective covert rate is obtained by optimizing the maximum jamming power of the primary transmitter (PT). The numerical results demonstrate that the combined effect of energy conversion efficiency and time allocation ratio of EH, in conjunction with the maximum jamming power of PT, provides a positive effective covert rate in the secondary network. Furthermore, it is evident that the maximum effective covert rate in the secondary network is greater when Willie has access to the perfect CSI of the SS-PR link than that when Willie only has access to the statistical CSI of the SS-PR link.