Outage Probability and Throughput of Multirelay SWIPT-WPCN Networks With Nonlinear EH Model and Imperfect CSI

This article investigates the simultaneous wireless information and power transfer-wireless powered communication network systems, where a multiantenna source transmits information to a multiantenna destination with the assistance of multiple single-antenna energy-constrained relays. For such a system, a transmission protocol is presented based on the $J$th best relay selection and the transmit antenna selection such that the information and power are transferred over the channel with the largest instantaneous power gain. Time switching receiver architecture is adopted at the relays for information decoding and energy harvesting (EH). The system information transmission performances in Rayleigh fading are analyzed with the nonlinear EH model and imperfect channel state information (CSI), and the closed-form expressions of the system outage probability and reliable throughput are derived. In order to provide more concise results, the corresponding approximate expressions are also derived at low and high signal-to-noise ratio. Numerical results show that our obtained theoretical results match Monte Carlo simulation results very well, demonstrating the effectiveness of our obtained analytical results. Besides, it also shows that the imperfect CSI of the source-to-relay link has greater impact on the system performance than that of the relay-to-destination link. Additionally, by using the nonlinear EH model, the false performance caused by the linear EH model can be reduced.