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.

中文翻译：

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多通道系统中的隐蔽无线通信

在这封信中，我们提出了一种多信道系统中的随机子信道选择隐蔽传输（RSCT）方案，以增强通信的隐蔽性。我们推导出最小检测错误概率（DEP）和平均有效率的表达式，在此基础上构建优化以最大化平均有效隐蔽率（ECR）。数值结果表明，与单通道方案相比，所提出的方案确实可以增强通信的隐蔽性，并且随着子通道数量的增加，性能得到提高。此外，证明存在最大化平均ECR的最佳子信道数量。