Non-orthogonal multiple access (NOMA) and energy harvesting (EH) are combined to introduce a dual-hop wireless sensor system. In particular, this paper considers a novel EH protocol based on time power switching-based relaying (TPSR) architecture for amplify-and-forward (AF) mode. We introduce a novel system model presenting wireless network with impacts of energy harvesting fractions and derive analytical expressions for outage probability and ergodic rate for the information transmission link. It confirmed that the right selection of power allocation for NOMA users can be performed to obtain optimal outage and ergodic capacity performance. Theoretical results show that, in comparison with the conventional solutions, the proposed model can achieve acceptable outage performance for sufficiently small threshold signal to noise ratio (SNR) with condition of controlling time switching fractions and power splitting fractions appropriately in considered TPSR protocol. We also examine the impacts of transmitting power at source, transmission rate, the other key parameters of TPSR to outage, and ergodic performance. Simulation results are presented to corroborate the proposed system.

In this paper, we investigate the performance of a secondary network in a cognitive radio network employing a non-orthogonal multiple access (NOMA) scheme to form a CR-NOMA system serving many destination users. In the secondary network of our proposed system, a device-to-device (D2D) scheme is deployed to further provide the signal transmission at a close distance of NOMA users in downlink, and such performance is evaluated under the situation of interference reception from the primary network. An outage performance gap exists among these NOMA users since different power allocation factors are assigned to the different destinations. Unlike existing NOMA schemes that consider fixed power allocation factors, which are not optimal in terms of outage performance, our proposed paradigm exhibits optimal outage in the scenario of D2D transmission. In particular, the outage performances in two kinds of schemes in term of existence of D2D link are further achieved. Simulation results validate the analytical expressions, and show the advantage of each scheme in the proposed CR-NOMA system based on outage performance and throughput.

This paper studies the wireless systems by implementing the full-duplex (FD) unmanned aerial vehicle (UAV) relay to allow two nearby base stations joint communicate to distant users. The nonorthogonal multiple access (NOMA) assisted networks and design of multiple-antenna users are considered in order to improve the users' performance. To overcome obstacles in transmission environment, such a model of the uplink (UL) and the downlink (DL) relying on UAV relay is suitable to forward signals to far users. Moreover, practical scenario of imperfect successive interference cancellation (SIC) at each receiver is considered as main reason of degraded performance. To evaluate specific performance metric, we derive the closed-form expressions of outage probability. In addition, the throughput in delay-limited transmission mode of UAV relay assisted UL/DL NOMA system is also considered thoroughly. The derivations and results showed that the higher number of antennas at users could effectively improve the system throughput and reduce the outage probability. The numerical simulation results further indicate the effectiveness of the proposed system and the correctness of theoretical analysis. INDEX TERMS Non-orthogonal Multiple Access, Unmanned Aerial Vehicle, outage probability, throughput, full-duplex, imperfect SIC.

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In this study, we deploy design and performance analysis in new system model using a relaying model, energy harvesting, and non-orthogonal multi-access (NOMA) network. It is called such topology as wireless powered NOMA relaying (WPNR). In the proposed model, NOMA will be investigated in two cases including single successive interference cancellation (SIC) and dual SIC. Moreover, the simultaneous wireless information and power transfer (SWIPT) technology can be employed to feed energy to relays who intend to serve far NOMA users. In particular, exact outage probability expressions are provided to performance evaluation. The results from the simulations are used to demonstrate the outage performance of the proposed model in comparison with the current models and to verify correct of derived expressions.