Raed Alhamad^1,*, Hatem Boujemaa²

CMC-Computers, Materials & Continua, Vol.73, No.3, pp. 5233-5244, 2022, DOI:10.32604/cmc.2022.030793

Abstract In this article, we optimize the powers associated to Non Orthogonal Multiple Access (NOMA) users, sensing and harvesting duration for Cognitive Radio Networks (CRN). The secondary source harvests energy from node A signal. Then, it senses the channel to detect primary source. Then, the secondary source transmits a signal that is reflected by Intelligent Reflecting Surfaces (IRS) so that all reflections have a zero phase at any user. A set Ii of reflectors are associated to user Ui. The use of M = Mi = 512, 256, 128, 64, 32, 16, 8 reflectors per user offers 45, 42, 39, 36, 33, 30, 27 dB gain… More >

Xiaoli He¹, Yu Song^2,3,*, Yu Xue⁴, Muhammad Owais⁵, Weijian Yang¹, Xinwen Cheng¹

CMC-Computers, Materials & Continua, Vol.70, No.1, pp. 195-212, 2022, DOI:10.32604/cmc.2022.017105

Abstract Spectrum resources are the precious and limited natural resources. In order to improve the utilization of spectrum resources and maximize the network throughput, this paper studies the resource allocation of the downlink cognitive radio network with non-orthogonal multiple access (CRN-NOMA). NOMA, as the key technology of the fifth-generation communication (5G), can effectively increase the capacity of 5G networks. The optimization problem proposed in this paper aims to maximize the number of secondary users (SUs) accessing the system and the total throughput in the CRN-NOMA. Under the constraints of total power, minimum rate, interference and SINR, CRN-NOMA throughput is maximized by… More >