基于扩维域能量弥散的隐蔽通信

Wireless communication technology is an indispensable means of information transmission in the thriving data era, while wireless security is particularly crucial in establishing the foundation of this era. In certain specific scenarios, the transmitter must not only ensure the security of the information content but also aim to achieve the transmission behavior of wireless signals without being detected by eavesdroppers. In response to the serious threat of radio eavesdropping, traditional covert communication methods depend on dispersing energy in one or two domains to minimize the probability of detection. For example, the code division multiple access technology based on the spread spectrum disperses energy in the frequency domain. Burst transmission technology disperses energy in discrete time intervals in the time domain while combining burst transmission with frequency hopping disperses energy in both time and frequency domains. The paper initially backtracks the physical nature of energy dispersion in wireless signal transmission. The covert communication model has been expanded from a single-domain energy dispersion to a multi-domain approach, encompassing the time, frequency, and space domains. By employing this model and tools such as radio propagation and digital signal processing theory, the paper models the energy dispersion of wireless signals in the three domains of time, frequency, and space. An energy detector is designed for eavesdropping in the three domains of time, frequency, and space. Subsequently, the expressions for capturing energy by the eavesdropper are derived using the multi-domain detection model. The expressions for the upper and lower boundaries of the eavesdropper’s detection probability using average noise energy as the threshold, as well as those for the upper and lower boundaries of the detection probability under the Neyman-Pearson energy detector, are also derived. Subsequently, combining theoretical derivation and analysis, we deduce and prove the guiding principles of multi-domain energy dispersion-based covert communication. Subsequently, the paper explores simulations and discussions, from a game-theoretic perspective, of the conditions for the covert presence of the transmitter under the multi-domain energy detection model and the strategies for improving the eavesdropper’s capabilities. Finally, the inherent contradiction and interaction mechanism between the covertness and reliability of wireless covert communications are revealed for practical design and realization. Then, the principle and technical approach to achieving wireless covert transmission are provided.