Distributed Hybrid NOMA/OMA User Allocation for Wireless IoT Networks

This work develops a distributed approach to user allocation in hybrid Internet of Things (IoT) networks, where nonorthogonal multiple access (NOMA) and orthogonal multiple access (OMA) techniques coexist for wireless user access. This hybrid approach facilitates massive connections of IoT devices with limited resources, exploiting the best of both multiplexing strategies. The directional beamforming environment is considered for mitigating user interference and providing spatial gains. Under this configuration, it aims at determining transmission techniques for individual users with the dual consideration of resource availability and geometric adjacency. To this challenge, an efficient distributed algorithm is developed via a novel realization techniques with a message-passing framework. The developed algorithm is rigorously investigated by in-depth theoretical analysis that ensures the optimality and the convergence of the global solution. Furthermore, numerical results also approve to outperform existing schemes consistently over a variety of network configurations that happen in wireless IoT networks.