Secrecy Energy Efficiency Maximization in an Underlying Cognitive Radio–NOMA System with a Cooperative Relay and an Energy-Harvesting User

Abstract

Security is considered a critical issue in the deployment of 5G networks because of the vulnerability of information that can be intercepted by eavesdroppers in wireless transmission environments. Thus, physical layer security has emerged as an alternative for the secure enabling of 5G technologies and for tackling this security issue. In this paper, we study the secrecy energy efficiency (SEE) in a downlink underlying cognitive radio (CR)—non-orthogonal multiple access (NOMA) system with a cooperative relay. The system has an energy-harvesting (EH) user and an eavesdropper, where the transmitter provides direct communication with a close secondary user and a distant secondary user via the relay. Our objective is to maximize the SEE of the CR-NOMA system under the constraints of a minimum information rate for the secondary users, a minimum amount of energy harvested by the EH user, and maximum power availability at the transmitter and the relay that still prevents them from causing unacceptable interference with the primary user. The proposed solution to maximize the SEE is based on the low-computational—complexity particle swarm optimization (PSO) algorithm. For validation purposes, we compare the optimization outcomes obtained by the PSO algorithm with the optimal exhaustive search method. Furthermore, we compare the performance of our proposed CR-NOMA scheme with the conventional orthogonal multiple access (OMA) scheme.

Orbital Angular Momentum-Based Multiple-Input-Multiple- Output with Receive Antenna Shift Keying for 6G

“…Thus, high-band technology has been adopted for mmWave communications [15]. Different concepts and strategies have been proposed in recent studies to improve the capacity of wireless transmissions, such as beamforming designs, resource allocation schemes, and multiple antenna-based schemes [16][17][18].…”

Performance Comparison of Massive MIMO System with Orthogonal and Nonorthogonal Multiple Access for Uplink in 5G Systems

“…The noise present on the channel is modeled as additive white Gaussian noise. The spread signal is sent through the two paths mentioned above to reach the base station [53,54], thus the signal received by relay from the source , , , 1,2,...,…”

“…Hs n , The spread signal is sent through the two paths mentioned above to reach the base station [53,54], thus the signal received by relay from the source…”

Particle Swarm Optimization-Based Secure Computation Efficiency Maximization in a Power Beacon-Assisted Wireless-Powered Mobile Edge Computing NOMA System

“…In the literature, PSO is considered a powerful optimization method since it has demonstrated high performance in solving optimization problems. For instance, in our previous works [1,18], the PSO technique has been investigated and applied for maximizing the secrecy sum rate and the secrecy energy efficiency of a cooperative NOMA network, respectively. In both cases, the results showed that the proposed PSO-based method accomplished yield very close to that obtained by the optimal exhaustive search method, but with the benefit of low computational complexity.…”

“…This motivated us to introduce PSO as a potential optimization solution in an innovative wireless-powered NOMA-enabled MEC system with a practical non-linear EH user. Different from the works in [1,18], where the downlink transmission from the transmitter to the receivers is only considered to carry messages, in this paper an uplink-downlink transmission scheme is studied where the AP integrates a MEC server to alieve the burden of the users. Moreover, the AP provides the WPT service and practical nonlinear EH and PB are integrated into the network.…”