Non-orthogonal access techniques have recently gained renewed interest in the context of next generation wireless networks. As the relative gain, with respect to traditionally employed orthogonal-access techniques depends on many factors, it is of interest to obtain insights by considering the simplest scenario, the two-user downlink (broadcast) channel where all nodes are equipped with a single antenna. Further, we focus on rate pairs that are in the vicinity of sum-rate optimalilty with respect to the capacity region of the broadcast channel. A simple and explicit characterization of the relative gain of non-orthogonal transmission with respect to orthogonal transmission is obtained under these conditions as an immediate consequence of the capacity regions of the two.
@article{arxiv.1709.08525,
title = {Comments on Downlink Non-Orthogonal Multiple Access: Relative Gain Subject to Near Sum-Rate Optimality},
author = {Uri Erez},
journal= {arXiv preprint arXiv:1709.08525},
year = {2017}
}