Case study and performance evaluation of MDMA-A non-orthogonal multiple access scheme for 5G cellular systems

Abstract

Multipath division multiple access (MDMA) has recently been proposed as a non-orthogonal multiple access scheme which exploits multipath domain to separate its users [1]. It is claimed that both the system capacity and total data throughput can be enhanced to a large amount. Yet, it is at its early stage of developments and it needs to be further investigated and clarified for its real use. In this paper, the feasibility and realizability of the MDMA cellular system are demonstrated by computer simulation. The receiver operation is also described in detail. Besides, the system performance is compared with those claimed in the original paper [1]. In addition, practical considerations on implementing the MDMA cellular system are discussed as well. With considerable amount of channel estimation error, it is shown that the system can still achieve 16 bps/Hz/cell with 300 BS antennas in cellular spectrum efficiency, which is an order of magnitude larger than the currently used first-generation to fourth-generation multiple access schemes. Thus, the MDMA can be considered as an implementable and spectrum efficient non-orthogonal multiple access scheme for future 5G systems.