Power Allocation and Scheduling for SWIPT Systems with Non-linear Energy Harvesting Model

In this paper, we design a resource allocation algorithm for multiuser simultaneous wireless information and power transfer systems for a realistic non-linear energy harvesting (EH) model. In particular, the algorithm design is formulated as a non-convex optimization problem for the maximization of the long-term average total harvested power at EH receivers subject to quality of service requirements for information decoding receivers. To obtain a tractable solution, we transform the corresponding non-convex sum-of-ratios objective function into an equivalent objective function in parametric subtractive form. This leads to a computationally efficient iterative resource allocation algorithm. Numerical results reveal a significant performance gain that can be achieved if the resource allocation algorithm design is based on the non-linear EH model instead of the traditional linear model.Comment: Accepted for presentation at the IEEE ICC 201

Joint energy harvesting time allocation and beamforming in two-way relaying network

Abstract. A two-way relaying system with amplify-and-forward technique, where relay stations (RSs) acquire the energy from transmission signal and interferences, is considered. The RSs use the energy to amplify the signal received from the transmitter and forward it to the receiver. Particularly, energy harvesting (EH) and time switching (TS) are deployed. Based on the TS architecture, we divide transmission time into two time slots, which are EH phase and information transmission (IT) phase. In the EH phase, the RSs harvest the energy from the received radio frequency (RF) signal. In the IT phase, the RSs process and forward the transmission signal to the destination by energy harvesting during the EH phase. From such a transmission scheme, we investigate the optimal time ratio of the EH and IT phase as well as the beamforming at RSs in order to acquire the sum rate maximization. Since the sum-rate maximization problem is nonconvex, we develop an iterative algorithm based on the majorization-minimization (MM) technique to solve the problem. Furthermore, we deployed two schemes to overcome the self-interference to see the efficiency of each scheme related to sum-rate performance. The results show that power transmission and a number of relay station have a major impact on the sum rate performance of the two-way relay system