Performance Comparison Among Hybrid NOMA Schemes Focusing on Outage Performance and Sum Rate Arrangement

The ever-growing number of users has brought about the challenge to identify a convenient technique for multiple access in next generation wireless communications. It has been seen that non-orthogonal multiple access (NOMA) technique provides far better performance than orthogonal multiple access (OMA) technique while taking advantage of the available resources. Interference can be minimized adequately through the use of Successive Interference Cancellation (SIC) when implemented extensively. But massive implementation increases the complexity of the system and as a result energy efficiency is reduced. To counteract the disadvantages of NOMA technique, interest in hybrid NOMA techniques has grown. Many recent papers have suggested hybrid NOMA schemes as a viable option to mitigate the disadvantages of NOMA. This paper performs an analysis of the performance between hybrid NOMA techniques which are hybrid NOMA-OMA, NOMA Space shift keying (NOMA-SSK) and Successive user relaying cooperative NOMA (SR-NOMA). A comparison of all these techniques is conducted to identify the best hybrid NOMA technique for 5G and beyond wireless communication. The expressions for sum rate and outage probability have been derived for all the techniques. Through analysis and simulation results depicted that NOMA-SSK provides the best performance in terms of sum rate and outage probability among the discussed schemes.