Optimal Resource Allocation for Two-User and Single-DF-Relay Network With Ambient Backscatter

In this paper, we investigate and analyze a two-user single decode-and-forward (DF) relay network with ambient backscatter communication capabilities, where the user nodes and the relay node are equipped with a wireless-powered device instead of embedded power supply. The DF relay and the user close to it are integrated into one device to reduce the deployment cost. We study the network throughput maximization problem by optimizing its resource allocation scheme and formulate an optimization problem for it. To solve this non-convex complicated multiple parameters joint optimization problem, a multi-step iterative optimization scheme (MSIO) is presented in this paper, which decomposes the original problem into two non-convex sub-problems. By exploiting the properties of their constrains, we convert them to the convex problems. Then, their optimal solutions are solved sequentially by the use of the convex optimization method. Finally, the iterative algorithm is employed to obtain the optimal solution of the original problem. The numerical results demonstrate the superiority of MSIO in improving system throughput.