Uplink Nonorthogonal Multiple Access in 5G Systems

In order to achieve diverse arrived power in uplink nonorthogonal multiple access (NOMA), an uplink power control scheme is proposed. The proposed scheme makes evolved NodeB (eNB) distinguish the multiplexing user equipments (UEs) in power domain. The outage performance and the achievable sum data rate for the proposed scheme are theoretically analyzed, and the closed-form expressions of outage probability and achievable sum data rate are derived. By simulation, we show that the outage performances are related to both the power backoff step and the target data rate. Compared with the traditional orthogonal multiple access (OMA) scheme, the proposed NOMA scheme significantly improves the achievable sum data rate.