Performance improvement of multiuser cognitive relay networks with full-duplex cooperative sensing and energy harvesting

Abstract

Energy harvesting cognitive radio has been considered as a promising technology in the fifth generation (5G) of wireless networks to solve the lack of spectrum and energy. In this paper, a novel wireless energy harvesting relay network is proposed for a multiuser cognitive radio to obtain the maximum throughput and decrease the false alarm and misdetection probabilities. The secondary user (SU) can harvest energy from solar sources while utilizing the licensed spectrum of the primary user (PU). Cooperative spectrum sensing is applied to improve the performance of the secondary network and decrease collision and sensing time. In this paper, the SU can carry out the transmitting, harvesting, and sensing using a full-duplex technique at the same time. Furthermore, we analyze the spectrum sensing of the proposed multiuser network under a data fusion scheme to discover the frequency hole. We demonstrate that the optimization problem can convert into a convex problem and achieve the optimal regulated rate of energy harvesting based on the Lagrangian function. This new network provides improved throughput, precise spectrum sensing, and high energy harvesting compared to the existing works studied so far. Finally, we verify the efficiency of the proposed method via simulation results and show that the optimal regulated rate is determined based on the priority of given constraints. the frequency band when the primary users (PUs) give up the channel [1][2][3]. A general summary of radio frequency energy harvesting systems was discussed in [4], including new research, system architecture, useful techniques, and available applications. Additionally, the applications of radio frequency energy harvesting are investigated in different networks, such as wireless sensor networks [5] and wireless charging networks [6]. An optimal cooperation protocol was proposed for an energy harvesting cognitive radio system in [7] to maximize the achievable throughput and provide the optimal decision, which consists of a two-level test. Furthermore, the average throughput was formulated under collision and energy constraints in [8] in order to achieve the optimal sensing time and threshold of the energy detector.Relay technology was investigated for cognitive radio networks in [9][10][11][12]. In [13], the effect of relaying * Correspondence: hfarrokhi@birjand.ac.ir This work is licensed under a Creative Commons Attribution 4.0 International License.