全双工接收机辅助的星地隐蔽信息时效性分析

Minimization of age of information for satellite-terrestrial covert communication with a full-duplex receiver

在现代通信技术不断发展的背景下,卫星通信在全球范围内的信息传输中扮演着至关重要的角色,然而,通信的安全性和信息的时效性始终是亟待解决的关键问题。以卫星—地面系统中隐蔽通信的信息新鲜度问题作为研究对象,该系统由卫星发射器Alice、地面全双工接收机Bob以及地面监听者Willie组成。在这种通信系统中,Alice在Willie的监测下尝试向Bob传输隐蔽信息,而Bob则发射干扰信号以混淆Willie,确保通信的隐蔽性。为此,首先针对Bob的平均信息时效性(AgeofInformation,AoI)和Willie的隐蔽约束进行了详细的理论建模。该模型考虑了通信过程中各类干扰和噪声的影响,从而为分析系统性能提供了坚实的理论基础。基于所建立的理论模型,进一步推导出了Alice在隐蔽性要求约束下的最优发射功率,以实现平均AoI的最小化。通过优化发射功率,Alice能够在保证隐蔽通信的前提下最大限度地提高信息的新鲜度,即尽量减少信息传输的延迟。随后,进行了数值模拟,验证了理论模型的准确性,并分析了发射功率和干扰功率对隐蔽性和平均AoI的影响。数值结果显示,通过合理调整发射和干扰功率,可以有效地在隐蔽性和信息时效性之间取得平衡。

In the context of the continuous development of modern communication technologies,the satellite communication plays a crucial role in global information transmission.However,the communication security and the timeliness of information are always key issues that urgently need to be addressed.The information freshness of covert communication in a satellite-terrestrial system consisting of a satellite transmitter Alice,a terrestrial full-duplex receiver Bob,and a terrestrial warden Willie,was taken as the object of the study.Particularly,Alice tried to transmit the covert information to Bob under the detection of Willie,while Bob emitted jamming signals to confuse Willie simultaneously.Therefore,a theoretical model was provided for the average age of information(AoI)of Bob and the covert constraint of Willie.This model considered the impact of various interferences and noises during the communication process,pro-viding a solid theoretical basis for analyzing system performance.Based on the theoretical model,a optimal transmit power of Alice was drived to minimize the average AoI with the constraint of covertness requirement.By optimizing the transmission power,Alice is capa-ble of ensuring the maximum the freshness of information while minimizing the delay in information transmission under the precondi-tion of covert communication.Subsequently,numerical simulations were carried out to verify the accuracy of the theoretical model,and the impacts of transmission power and interference power on the concealment and average AoI were analyzed.Finally,the numerical re-sults showed that the balance between concealment and AoI could be effectively achieved by reasonably adjusting the transmission and jamming power.