Performance and Security Enhancement in Multi-band Uplink NOMA Networks with Selection of the Users and Energy Harvesting

In this paper, uplink secure transmission in a non-orthogonal multiple access (NOMA) network is investigated by selection of the users for data transmission to the base station (BS) and also jammers with the capability of energy harvesting. In fact, each frame has two phases. In the first phase, jammers harvest energy from BS and in the second phase, the selected users transmit their data to BS using NOMA technique while selected jammer emits the artificial noise for confusing the eavesdropper. In fact, the problem is maximizing the secrecy throughput by selection of the users for uplink data transmission to BS in each frequency channel and suitable jammers to make the artificial noise for eavesdropper with constraints on the secrecy outage probability (SOP) and connection outage probability (COP). The problem is solved based on the convex optimization methods and Karush-Kuhn-Tucker (KKT) conditions. An algorithm is proposed for solving the problem and the system performance is evaluated. Simulation results present that the proposed algorithm has the better performance for the throughput and security of the network in comparison with the benchmark algorithms in different situations and scenarios.