GFDM Based Wireless Powered Communication for Cooperative Relay System

Green and sustainable communications are crucial for cellular devices and the Internet of Things (IoT) devices in the fifth generation (5G) mobile communication system. Wireless-powered communication (WPC) provides a successful technical paradigm to support wireless information transmission for mobile devices by using harvested radio-frequency (RF) energy. In the meantime, non-orthogonal multicarrier transmission techniques, typically represented by the generalized frequency-division multiplexing (GFDM), can not only enhance spectrum efficiency but also improve the flexibility of resource allocation due to its fine-granularity sub-block. In this paper, a GFDM-based cooperative relay system model is proposed to improve the quality of experience of the cell-edge user. Specifically, the system is composed of one source node, one destination node (cell-edge user), and one relay node. The source node transmits a signal to the destination node and the relay node. The relay node performs information transmission and power transfer to the destination node by using different GFDM sub-block sets. The destination node combines the signals from the source node and relay node. In order to maximize the information rate at the destination node subject to the minimum harvested energy, a joint sub-block, sub-block power, and subslot allocation-based WPC scheme is proposed. To solve the non-convex optimization problem, an iterative algorithm is proposed and its effectiveness is validated by simulations. The simulation results demonstrate that the GFDM-based WPC scheme outperforms the orthogonal frequency-division multiplexing (OFDM), and the subslot optimization can significantly increase the information rate at the destination node.