Outage and Throughput Performance of NOMA Inspired Cognitive IoT Network with Imperfect SIC

In this paper, we study and investigate non-orthogonal multiple access (NOMA) inspired cognitive Internet-of-Things (IoT) network to enhance the outage and throughput performance of secondary NOMA user and IoT user. In a cognitive IoT network, the information from the source to user located at the centre of secondary cell is transmitted via direct link. In contrast, an IoT relay-aided cooperative link is used to transmit the information to cell-edge user. The IoT relay also acts as a master node for IoT applications and delivers the information to IoT device in the secondary network during the same time slot used to relay the information to cell-edge user. The approximate closed-form expressions of outage probability (OP) and throughput are derived in the presence of imperfect successive interference cancellation (SIC). The analytical expressions of OP and throughput are validated through numerical simulations. Furthermore, the effect of maximum allowable power requirement and SIC error on the system throughput has been studied, and the results are compared with the OMA-based transmission scheme.