Achieving Covert Communication in Underlay Cognitive Radio Networks Using a Multi-Antenna Receiver

Covert communication can hide the information transmission process and prevent the communication behavior from being detected by eavesdroppers. In this paper, we propose a multi-antenna underlay cognitive radio networks (UCRN) covert communication scheme, which selects the best antenna of the secondary receiver (SR) to receive covert information from the secondary transmitter (ST), and then selects an antenna from the remaining antennas to generate interference noise with different power. The uncertainty of interference power is used to realize the covert communication of multi-antenna receiver. We derive the minimum detection error rate, and transmission outage probability of Willie, and evaluate the covert performance of the scheme. The numerical results show that the maximum interference tolerance of the primary receiver (PR) and the maximum interference power of multiple antennas in SR can make ST realize covert transmission.