Sum Throughput Maximization for MIMO Wireless Powered Communication Networks with Discrete Signal Inputs

Wireless powered communication networks (WPCNs) utilize the wireless energy transfer (WET) technique to facilitate the wireless information transmission (WIT) of nodes. We propose a two-step iterative algorithm to maximize the sum throughput of the users in a MIMO WPCN with discrete signal inputs. Firstly, the optimal solution of a convex power allocation problem can be found given a fixed time allocation; Secondly, a semi closed form solution for the optimal time allocation is obtained when fixing the power allocation matrix. By optimizing the power allocation and time allocation alternately, the two-step algorithm converges to a local optimal point. Simulation results show that the proposed algorithm outperforms the conventional schemes, which consider only Gaussian inputs.