Mean-Field Transmission Power Control in Dense Networks

TL;DR

This paper analyzes uplink power control in dense wireless networks, comparing NOMA and CDMA protocols, and demonstrates that NOMA achieves higher efficiency at equilibrium in a non-cooperative setting.

Contribution

It introduces a game-theoretic analysis of NOMA versus CDMA, establishing the existence and uniqueness of equilibrium strategies and showing NOMA's superior performance.

Findings

NOMA outperforms CDMA in channel access efficiency.

Equilibrium strategies are proven to exist and be unique.

Social welfare is higher under NOMA at equilibrium.

Abstract

We consider uplink power control in wireless communication when a large number of users compete over the channel resources. The CDMA protocol, as a supporting technology of 3G networks accommodating signal from different sources over the code domain, represents the orthogonal multiple access (OMA) techniques. With the development of 5G wireless networks, non-orthogonal multiple access (NOMA) is introduced to improve the efficiency of channel allocation. Our goal is to investigate whether the power-domain NOMA protocol can introduce performance improvement when the users interact with each other in a non-cooperative manner. It is compared with the CDMA protocol, where the fierce competition among users jeopardizes the efficiency of channel usage. In this work, we conduct analysis with an aggregative game model, and show the existence and uniqueness of an equilibrium strategy. Next, we adopt the social welfare of the population as the performance metric, which is the average utility achieved by the user population. It is shown that under the corresponding equilibrium strategies, NOMA outperforms CDMA by higher efficiency of channel access for uplink communications.