Cognitive jammers assisted covert communication in cognitive radio networks

In this work, we investigate the covert communication in cognitive radio (CR) networks with the existence of multiple cognitive jammers (CJs). Specifically, the secondary transmitter (ST) helps the primary transmitter (PT) to relay information to primary receiver (PR), as a reward, the ST can use PT's spectrum to transmit private information against the eavesdropper (Eve) under the help of one selected cognitive jammer (CJ). Meanwhile, we propose three jammer-selection schemes, namely, link-oriented jammer selection (LJS), min-max jammer selection (MMJS) and random jammer selection (RJS). For each scheme, we analyze the average covert throughput (ACT) and covert outage probability (COP). Our simulation results show that CJ is helpful to ST's covert communication, the expected minimum detection error probability and ACT can be significantly improved with the increase of false alarm of CJ. Moreover, the LJS scheme achieves best performance in ACT and COP, followed by RJS scheme, and MMJS scheme shows the worst performance.