  Cognitive radio (CR) and non-orthogonal multiple access (NOMA) have been
deemed two promising technologies due to their potential to achieve high
spectral efficiency and massive connectivity. This paper studies a
multiple-input single-output NOMA CR network relying on simultaneous wireless
information and power transfer (SWIPT) conceived for supporting a massive
population of power limited battery-driven devices. In contrast to most of the
existing works, which use an ideally linear energy harvesting model, this study
applies a more practical non-linear energy harvesting model. In order to
improve the security of the primary network, an artificial-noise-aided
cooperative jamming scheme is proposed. The artificial-noise-aided beamforming
design problems are investigated subject to the practical secrecy rate and
energy harvesting constraints. Specifically, the transmission power
minimization problems are formulated under both perfect channel state
information (CSI) and the bounded CSI error model. The problems formulated are
non-convex, hence they are challenging to solve. A pair of algorithms either
using semidefinite relaxation (SDR) or a cost function are proposed for solving
these problems. Our simulation results show that the proposed cooperative
jamming scheme succeeds in establishing secure communications and NOMA is
capable of outperforming the conventional orthogonal multiple access in terms
of its power efficiency. Finally, we demonstrate that the cost function
algorithm outperforms the SDR-based algorithm.
