Joint UAV Deployment, Power Allocation, and Coalition Formation for Physical Layer Security in Heterogeneous Networks
Yalin Zhang, Xiaozheng Gao, Neng Ye, Dusit Niyato, Zhu Han, Kai Yang
Abstract
In the coming sixth-generation era, unmanned aerial vehicles (UAVs) have been explored for convenient air access and strong environmental adaptability to provide communication services for ground Internet-of-Things (IoT) devices. However, the inherent broadcast nature of wireless makes UAV communications vulnerable to eavesdropping attacks. This paper explores a secure uplink communication in a heterogeneous network, where a UAV provides communication services to ground IoT nodes in the presence of an eavesdropper. We propose a transmission scheme to maximize the overall sum secrecy rate, in which the cooperative jamming technique and coalition formation game are employed, and the UAV endurance is considered. Specifically, a double-layer optimization problem is formulated, including a non-convex optimization problem in the lower layer, and a game theory problem in the upper layer. We use block coordinate descent and successive convex approximation methods to decompose the lower layer problem into UAV deployment and power allocation sub-problems, and convert them into a difference of two convex functions programming problem and a second-order cone programming problem, respectively. Moreover, we develop an algorithm to solve the upper layer problem, obtaining a stable coalition formation. Simulation results show that the proposed transmission scheme can effectively improve the overall sum secrecy rate, and has dynamic adaptability to eavesdropping attacks.