Power Control Scheme for NOMA Random Access with Imperfect SIC

In this paper, power control is considered to improve the performance of uplink random access in non-orthogonal multiple access (NOMA) employing imperfect successive interference cancellation (SIC). First, the effect of imperfect SIC is modeled exploiting the sigmoid function. Then, in order to improve the performance of the NOMA SIC receiver, we propose an uncoordinated power control method that makes the power received from each terminal different. Based on the simulation results, it is shown that the proposed scheme results in performance improvement compared to the conventional power control method in the orthogonal multiple access (OMA) or other power control schemes in NOMA.