Abstract:

The rapid growth in the use of mobile devices and wireless services has led to a shortage of available spectrum for communication. To solve this issue, Cognitive Radio (CR) has been introduced. CR is a type of wireless communication that allows transmitters/receivers to detect vacant channels and avoid occupied ones, maximizing the use of available radio-frequency spectrum. Various proposed techniques mentioned here to improve spectral efficiency, with Non-Orthogonal Multiple Access (NOMA) having potential for use in the 5G network as it can accommodate more users. However, integrating NOMA techniques into CR networks presents significant technical challenges. To enhance NOMA's performance, Multiple Input and Multiple Output (MIMO) techniques are being employed in CRNs. Studies show that MIMO techniques can significantly improve the performance of CRNs with NOMA. This paper reviews the areas in which Cognitive Radio inspired NOMA can be used to improve both Spectral Efficiency (SE) and Energy Efficiency (EE). In addition, our paper also covers the challenges and potential research directions for the future.

Description:

Cognitive Radio, NOMA, SWIPT, MIMO, Green Communication, CR-NOMA. Energy Efficiency, Spectral Efficiency