Physical Layer Security Transmission In UAV Swarms Based On Game Theory

In recent years,unmanned aerial vehicles(UAVs)have gained extensive attention and research in academia and industry based on their widely known advantages such as excellent maneuverability and no casualties.Compared with a single drone,a UAV swarm has a greater range of coverage and resilience to single-node failures,and it can effectively complete complex tasks in a collaborative manner,thus it is widely used in military and civilian fields.The reliable and safe communication between UAVs is the prerequisite for the efficient cooperation of UAVs.However,due to the openness of wireless channels,malicious eavesdroppers can illegally obtain important information transmitted in UAV swarms,such as monitoring airports or nuclear power plants,which may pose a serious security threat to people’s lives and property.Therefore,it is very important to ensure the security of communications in UAV swarms against eavesdropping.Compared with the traditional cryptographic-based methods,the Physical Layer Security(PLS)technology is an effective alternative method.It does not need a lot of computing overhead and key distribution in advance,which is more suitable for the UAV swarm with limited resources and dynamic and changeable members.Although PLS has received much attention in traditional wireless communication system,the research on the anti-eavesdropping of UAV swarms at the physical layer is still in its initial stage.The existing research only considers the communication network scenario involving one or two UAVs,aiming to protect a single legal communication link or to protect the communication between a UAV and multiple ground users.However,the physical layer security transmission in UAV swarms is underexplored.We consider a typical UAV swarm architecture,which consists of multiple UAV-transmitter(UTs),multiple UAV-receiver(URs)and multiple UAV-eavesdropper(UEs).In this case,each UT collects sensing data from its coverage of interest and then delivers the data to a UR for further processing,and multiple UAV-eavesdroppers(UEs)intend to wiretap on the legitimate links.From the perspective of physical layer security,we design a two-stage game framework consisting of a UT-UR association stage and a UT cooperative transmission stage to protect all legitimate UT-UR links against UEs.Specifically,we take into account the limited capacities and throughput requirements of URs,and the transmission power constraints of UTs.We formulate the UT-UR association problem and the relay selection problem of UT into a many-to-one matching game and an overlapping coalition formation(OCF)game,respectively.We propose the corresponding algorithms to solve these two sequential problems.At the same time,this thesis analyzes the proposed algorithms theoretically,and proves the convergences and stabilities of the algorithms.Simulation results show the effectiveness of our proposed algorithms and the reliability of the two-stage game framework in improving the secrecy performance.