Sum-rate maximization for UAV-enabled two-way relay systems

In this paper,an Unmanned Aerial Vehicle(UAV)-enabled two-way relay system with Physical-layer Network Coding(PNC)protocol is considered.A rotary-wing UAV is applied as a mobile relay to assist two ground terminals for information interaction.Our goal is to maximize the sum-rate of the two-way relay system subject to mobility constraints,propulsion power consumption constraints,and transmit power constraints.The formulated problem is not easy to solve directly because it is a mixed integer non-convex optimization problem.Therefore,we decompose it into three sub-problems,and use the mutation arithmetic of the Genetic Algorithm(GA)and Successive Convex Approximation(SCA)to dispose.Besides,a high-efficiency iterative algorithm is proposed to obtain a locally optimal solution by jointly optimizing the time slot pairing,the transmit power allocation,and the UAV trajectory design.Numerical results demonstrate that the proposed design achieves significant gains over the benchmark designs.