  In this paper, we present a physical-layer security scheme that exploits
artificial noise (AN) to secure the downlink legitimate communications and
transfer energy to nodes operating under non-cooperative non-orthogonal
multiple-access (NOMA) scenario. The nodes employ a joint time-switching and
power-switching scheme to maximize the harvested energy. We provide necessary
analysis and derivations for the optimization parameters and find the optimized
transmission parameters that maximize the minimum secrecy rate among users
while meeting constraints on minimum transferred energy and outage
probabilities at the nodes through an exhaustive grid-based search. Our
analysis and simulations prove the feasibility of securing the communication
among NOMA nodes, while transferring energy and meeting outage probability
constraints.
