基于多径信道能量随机动态打散的隐蔽无线通信方案

为应对无线通信中的未知非法检测威胁，该文提出一种随机跳径隐蔽通信方案，实现了信号能量在多径上随机动态打散。首先，基于我方多径信道信息设计了隐蔽传输策略，并构建了敌方检测模型。接着，通过引入相关性纠偏因子，分别推导了所提方案、选最强径方案和经典最大比发送方案的敌方平均接收信噪比(SNR)闭式表达式，并基于曲线拟合的方法计算了我方最小平均隐蔽概率，完成了隐蔽性能定性和定量评估。然后，推导了我方平均接收信噪比闭式解，分析了系统速率性能。仿真实验表明，所提方案不仅在未知敌方任何信息的一般情形下具有隐蔽性能优势，而且在敌方抵近我方的极端情形下可以最大程度地解决隐蔽通信失效问题。

Covert Wireless Communication Scheme Based on Random Dynamic Diffusion of Energy over Multipath Channel

Focusing on the unknown and illegal detecting threat of wireless communication, a random path hopping scheme is proposed in this paper, which achieves random dynamic diffusion of signal energy on multipath. Firstly, a covert transmission strategy is constructed based on the multipath channel as well as the detecting model. Secondly, the closed expressions of the enemy's average received SNR (Signal to Noise Ratio) are derived respectively under the proposed scheme, the random path hopping scheme and the classic maximum ratio transmission scheme, and the minimal average covert probability is calculated by the curve fitting method for the qualitative and quantitative evaluation of covert performance. Finally, the closed expression of the legal receiver’s SNR is also derived for evaluating rate performance. The simulations reveal that the proposed scheme not only has the advantage of covert performance in the general case of enemy unknown, but also can solve the disabled problem of covert communication most effectively in the extreme case of enemy approaching the legal receiver.