Full/half duplex cooperative relaying NOMA network under power splitting based SWIPT: Performance analysis and optimization

Abstract

Non-orthogonal multiple access (NOMA) and full duplex (FD) relaying are two promising techniques to enhance the spectral efficiency of the fifth generation (5G) wireless networks. Simultaneous wireless information and power transfer (SWIPT) technique has recently emerged as an effective solution to improve the energy efficiency of wireless networks. This paper investigates outage and throughput performance of SWIPT enabled FD cooperative NOMA network under power splitting relaying (PSR) protocol, i.e., SWIPT enabled FD-PSR-NOMA network. We assume a single cell network consisting of a base station (BS) and two pre-paired users, i.e., a near user and a far user, where the near user acts as FD relay to assist the BS for information delivery to the far user, and power splitting (PS) technique is used at the relay for energy harvesting (EH). We derive analytical expressions for the outage probabilities experienced by the downlink users, system outage probability and delay limited system throughput under imperfect successive interference cancellation (i-SIC). We also derive analytical expressions for outage probabilities and throughput of SWIPT enabled half duplex (HD) cooperative NOMA network under PSR, i.e., SWIPT enabled HD-PSR-NOMA network. The optimal power allocation (OPA) factor at the BS and optimal power splitting (OPS) factor at the relay that independently minimizes the asymptotic system outage probabilities of SWIPT enabled FD/HD-PSR-NOMA networks are determined. Further, we explore the jointly optimal power allocation and power splitting factor that minimize the system outage probability. Furthermore, we derive analytical expression for the OPS factor that maximizes the asymptotic system throughput. We provide extensive numerical and simulation results to establish that system outage and throughput improve significantly under the proposed schemes.