A comparative performance analysis among Hybrid NOMA Schemes for 5th Generation (5G) and beyond Wireless Communications

Abstract

A full-scale implementation of 5G and beyond wireless communication systems require more effective radio access techniques. To address this issue non-orthogonal multiple access (NOMA) technique is considered as a most promising technology in recent times. NOMA is superior in terms of spectral efficiency and user density than the existing orthogonal multiple access (OMA) technique utilizing the limited resources, though NOMA allows controllable interferences by non-orthogonal resource allocation. Successive Interference Cancellation (SIC) can efficiently mitigate the impact of interference when implemented massively, but it raises computational complexity significantly, hence, reduces energy efficiency. In order to alleviate the drawbacks of NOMA, hybrid NOMA schemes have been proposed in recent research works. This thesis work focuses on comparative performance analysis among hybrid NOMA schemes such as MIMO-NOMA, NOMA-GSSK and STBC-CNOMA. The purpose of the work is also to recommend the best suited hybrid scheme for next generation wireless networks. Numerical analysis and simulation results validate the superiority of the NOMAGSSK scheme in terms of bit error probability and spectral efficiency than other two promising schemes. The findings also suggest that STBC-CNOMA certainly outweighs other two schemes considering system complexity and energy efficiency.