5G 및 Beyond 5G를 위한 고용량 제약 조건에서 다중 안테나 기술에 대한 NOMA와 OMA 비교

Abstract

Non-orthogonal Multiple Access (NOMA) is always considered the best candidate for Fifth-Generation (5G) wireless communication network as it demands mass connectivity, low latency and increased data rate. In the literature, Orthogonal Multiple Access (OMA) is compared with NOMA for the sum rate and capacity, where NOMA leads the OMA in terms of capacity and huge connectivity due to the freedom of non-orthogonality. However, these comparisons are carried out rather for single antenna system or a limited number of multiple transmitting antennas. For multiple-input-multiple-output (MIMO) system, the capacity comparison is quite different for NOMA and OMA, especially where the number of users out-number the transmitting antenna. This paper answers this query that what is the role of multiple access techniques for massive MIMO scenarios under vital requirements i.e. increased channel capacity, sum rate, and mass connectivity. Some special cases are also identified to highlight the importance of using both OMA and NOMA together as a hybrid system or switching to either of it at the physical layer.