Throughput Evaluation of UL-NOMA Systems with Successive Interference Cancellation and Repetition

Recently, as the number of Internet of Things (IoT) devices has been increasing, there is a growing demand for communications utilizing radio frequency efficiently. Nonorthogonal multiple access (NOMA) is a promising scheme for realizing it. In this paper, major attention has been focused on the combination of power domain NOMA in uplink channel (UL-PD-NOMA), configured grant (CG) transmission scheme, and successive interference cancellation (SIC). We show results of computer simulation to evaluate the UL-PD-NOMA+CG+SIC system. In the simulation, we assumed a simple scheme where communications take place under some simple assumptions. Many devices (~ 10
⁶
/km
²
) of user equipment (UE) in a single circular service area transmit packets sporadically to one base station (BS) located at the center of the service area. The UEs share the same radio frequency band and the BS performs SIC to separate superimposed signals. All packets are replicated and transmitted repeatedly. This “repetition-SIC” method is aimed at improving throughput. The packets transmitted with repetition enter successive packet time slots. The simulation results have shown that normalized throughput value of the packet increases from 2.70 to 3.59 when the whole system is not so busy, compared to the case which lacks packet repetition. Therefore, we confirm the improvement in performance of the UL-PD-NOMA+CG+SIC system.