Nonorthogonal Replication Scheme for ALOHA Uplink in LPWAN

In this work, we address a novel replication scheme for Internet-of-Things (IoT) low power wide area networks (LPWAN), considering the ability of a gateway to recover, through successive interference cancellation (SIC), superposed signals in the power domain. We show that the introduced mathematical framework matches the Monte Carlo simulations. The proposed scheme outperforms typical transmission schemes, at least from 1 to 2 orders of magnitude, in terms of outage probability. We also show that the scheme fits well with previous replication schemes, outperforming their versions without non-orthogonal replications. Moreover, we show that the proposed scheme can be robust to cases with high SIC imperfection, presenting slight performance losses even in very harsh scenarios, as long as the constraints are met. Finally, we conclude that the proposed scheme can be more energy efficient than previous replication schemes and achieve better reliability in traffic-loaded networks.