TY - JOUR N1 - This version is the author accepted manuscript. For information on re-use, please refer to the publisher?s terms and conditions. EP - 43449 AV - public Y1 - 2018/07/26/ VL - 6 SP - 43440 TI - Optimization for Maximizing Sum Secrecy Rate in SWIPT-enabled NOMA Systems KW - NOMA KW - Erbium KW - Resource management KW - Wireless communication KW - Downlink KW - Receivers KW - Communication system security A1 - Tang, J A1 - Dai, T A1 - Cui, M A1 - Zhang, X A1 - Shojaeifard, A A1 - Wong, KK A1 - Li, Z JF - IEEE Access SN - 2169-3536 UR - http://dx.doi.org/10.1109/ACCESS.2018.2859935 ID - discovery10054691 N2 - OAPA In this paper, we study secrecy simultaneous wireless information and power transfer (SWIPT) in downlink nonorthogonal multiple access (NOMA) systems comprising a base station (BS), multiple information receivers (IRs), and multiple energy receivers (ERs) that have potential to wiretap the IRs. The goal of this paper is to maximize the sum secrecy rate (SSR) of the system subject to the individual IR’s minimum data rate requirement and the individual ER’s minimum harvested energy requirement. The corresponding problem involves resource allocation via max-min function, which is non-convex and difficult to solve directly. In order to tackle this, we first transform the original non-convex problem to a sequence of convex subproblems which can be solved simultaneously. Hence, a closedform solution of the optimal power allocation policy is derived based on the Karush-Kuhn-Tucker (KKT) conditions. Numerical results validate the theoretical findings and demonstrate that significant performance gain over the orthogonal multiple access (OMA) scheme in terms of SSR can be achieved by the proposed algorithm in a SWIPT-enabled NOMA system. ER -