Cooperative NOMA system with incremental relaying and energy harvesting: Performance analysis and optimization

Abstract

AbstractThis article investigates the outage performance of incremental relaying based energy harvesting non‐orthogonal multiple access (IR‐EH‐NOMA) system. Firstly, we describe the IR‐EH‐NOMA protocol considering downlink user assisted relaying and power splitting (PS) based EH strategy. We derive analytical expressions for the outage probabilities experienced by the downlink users and the system outage probability of IR‐EH‐NOMA network, in the presence of imperfect successive interference cancellation (I‐SIC). For comparison, we derive the corresponding outage expressions for the conventional cooperative relaying based NOMA network with EH (CR‐EH‐NOMA network) as well. We provide extensive numerical and Monte‐Carlo simulation results to establish the supremacy of IR‐EH‐NOMA system over CR‐EH‐NOMA system in terms of the outage performance. We separately derive analytical expressions for (i) the optimal power allocation (OPA) factor at the source and (ii) the optimal power splitting (OPS) factor at the relay that minimizes the asymptotic system outage probability of the considered networks. With the help of numerical and simulation investigations, we establish that the system outage of the considered networks improve significantly when OPA and OPS factors are selected according to the criterion described in the article. The analytical results are validated by extensive simulation studies.