NOMA Versus OMA: Scheduling to Minimize the Age of Information

In this work, we consider multiple internet-of-things devices (IoTDs) sensing and reporting the status of a time-varying signal to a central node. We analytically compare the performance of orthogonal multiple access (OMA) and non-orthogonal multiple access (NOMA) scheduling schemes for the expected system age of information (AoI) and throughput for generic channel distribution. Further, an IoTD pairing scheme is proposed that adaptively decides to pair IoTDs to minimize AoI depending on the operating transmission signal-to-noise ratio while only requiring the knowledge of channel distribution. Lastly, the proposed results are verified through numerical evaluation.