Covert Wireless Communication in Multichannel Systems

In this letter, we propose a random sub-channel selection covert transmission (RSCT) scheme in multi-channel systems to enhance the covertness of communication. We derive the expression of minimum detection error probability (DEP) and the average effective rate, based on which an optimization is constructed to maximize the average effective covertness rate (ECR). Numerical results indicate that, compared with the single-channel scheme, the proposed scheme can indeed enhance the covertness of the communication and the performance is improved as the number of sub-channels increases. Besides, it is demonstrated that there exists an optimal number of sub-channels for maximizing the average ECR.