Sum-Throughput Maximization for MIMO Full-Duplex Wireless Powered Communication Network with Finite Alphabet Inputs

In this paper, we maximize the sum-throughput of a multi-user MIMO full-duplex wireless powered communication network (FD-WPCN) by jointly optimizing the precoding matrices and time allocation vector. In particular, we consider a more practical scenario with energy causality and finite alphabet inputs. The original optimization problem is non-convex and intractable. We prove that the time allocation problem is convex with the precoding matrices fixed. We also simplify the optimal precoder design to a convex power allocation problem for a given time allocation vector. By optimizing the precoding matrices and the time allocation vector alternately, we propose a two-step iterative algorithm to find the optimal solution. The simulation results show that our scheme outperforms other benchmark schemes significantly.