Survey on NOMA and Spectrum Sharing Techniques in 5G

Two innovations multiple access technologies for efficient spectrum use in future wireless communications standards, non-orthogonal multiple access (NOMA) and cognitive radio (CR). The NOMA is one of the most promising performance improvement methods in 5G cells and CR will make the most of dynamic spectrum access and diversity throughout the broad spectrum possible, to alleviate the spectrum scarcity problem and meet the huge demands for wireless connectivity. The paper aims to look and survey at methods and techniques that maximize spectrum efficiency and performance. In order to evaluate the important functions of spectrum optimization techniques, a descriptive approach was used. We found that these are effective methods to solve the problems of a specific frequency spectrum and additional spectral efficiency benefits would be provided. combining NOMA and CR can meet 5G standards. This article discusses the basic principle of NOMA, the basic concept of cognitive radio, the spectrum sharing way, and the advantages and challenges of NOMA and CR spectrum sharing.

I. INTRODUCTION

Wireless networking has been witnessed to a revolution in the past few decades through various approaches. The key wireless networking networks multiple users are assigned to orthogonal radio services within the time, frequency, and code domain, or their combination by traditional Orthogonal multiple access (OMA) schemes, such as frequency division multiple access (FDMA), time division multiple access (TDMA), and code division multiple access (CDMA) have been used. Orthogonal frequency division multiple access (OFDMA) for 1G, 2G, 3G, and 4G respectively.