A Simple Study on the Optimality of Hybrid NOMA

TL;DR

This paper investigates the optimality of hybrid NOMA in a two-user scenario, demonstrating through analysis and simulations that equal bandwidth access can be optimal, maintaining compatibility with legacy networks.

Contribution

It provides an analytical and simulation-based study showing that conventional hybrid NOMA remains optimal when users access equal bandwidth resources in a simple two-user setting.

Findings

Hybrid NOMA can be optimal with equal bandwidth access.

Conventional hybrid NOMA maintains compatibility with legacy networks.

Analytical and simulation results support the optimality claim.

Abstract

The key idea of hybrid non-orthogonal multiple access (NOMA) is to allow users to use the bandwidth resources to which they cannot have access in orthogonal multiple access (OMA) based legacy networks while still guaranteeing its compatibility with the legacy network. However, in a conventional hybrid NOMA network, some users have access to more bandwidth resources than others, which leads to a potential performance loss. So what if the users can access the same amount of bandwidth resources? This letter focuses on a simple two-user scenario, and develops analytical and simulation results to reveal that for this considered scenario, conventional hybrid NOMA is still an optimal transmission strategy.