Jammer Assisted Covert Communication with Cognitive Radio

This work proposes a covert communication scheme in a cognitive radio network where a secondary transmitter (ST) transmits confidential information to a secondary receiver under the protection of a jammer. Specifically, we first analyzed the communication performance of the system under both correct and incorrect decisions of ST. We then derive the average minimum detection error probability under the two decisions of ST and obtain the global average minimum detection error probability as the covertness constraint. To maximize the average effective covert rate, we jointly optimize the transmission power of ST and the maximum transmission power of the jammer while satisfying constraints. Our examination shows that the proposed scheme can effectively improve the covert performance and the average effective covert rate of the system compared to the no-jammer scheme.