Coordinated Multi-Point (CoMP) Transmission in Downlink Multi-cell NOMA Systems: Models and Spectral Efficiency Performance

TL;DR

This paper proposes a framework for using coordinated multi-point transmission in downlink multi-cell NOMA systems, demonstrating spectral efficiency gains over traditional OMA-based CoMP through numerical analysis.

Contribution

It introduces a novel CoMP-NOMA framework with distributed power allocation, analyzing its applicability, performance, and potential challenges in future cellular networks.

Findings

CoMP-NOMA outperforms CoMP-OMA in spectral efficiency.

The framework effectively manages users with strong signals from multiple cells.

Numerical results confirm significant spectral efficiency gains.

Abstract

We outline a general framework to use coordinated multi-point (CoMP) transmission technology in downlink multi-cell non-orthogonal multiple access (NOMA) systems considering distributed power allocation at each cell. In this framework, CoMP transmission is used for users experiencing strong receive-signals from multiple cells while each cell adopts NOMA for resource allocation to its active users. After a brief review of the working principles of different CoMP schemes, we identify their applicability and necessary conditions for their use in downlink multi-cell NOMA system. After that, we discuss different network scenarios with different spatial distributions of users and study the applicability of CoMP schemes in these network scenarios. To the end, a numerical performance evaluation is carried out for the proposed CoMP-NOMA systems and the results are compared with those for conventional orthogonal multiple access (OMA)-based CoMP systems. The numerical results quantify the spectral efficiency gain of the proposed CoMP-NOMA models over CoMP-OMA. Finally, we conclude this article by identifying the potential major challenges in implementing CoMP-NOMA in future cellular systems.