Application of Non-orthogonal Multiple Access in LTE and 5G Networks

TL;DR

This paper reviews the emerging non-orthogonal multiple access (NOMA) technology, highlighting its integration with MIMO, cooperative strategies, cognitive radio, and standardization efforts in LTE and 5G networks, emphasizing spectral efficiency improvements.

Contribution

It provides a comprehensive overview of NOMA's integration with advanced technologies and its standardization status in LTE and 5G networks.

Findings

NOMA significantly improves spectral efficiency.

NOMA can be combined with MIMO and cooperative techniques.

Standardization activities for NOMA in 5G are underway.

Abstract

As the latest member of the multiple access family, non-orthogonal multiple access (NOMA) has been recently proposed for 3GPP Long Term Evolution (LTE) and envisioned to be an essential component of 5th generation (5G) mobile networks. The key feature of NOMA is to serve multiple users at the same time/frequency/code, but with different power levels, which yields a significant spectral efficiency gain over conventional orthogonal MA. This article provides a systematic treatment of this newly emerging technology, from its combination with multiple-input multiple-output (MIMO) technologies, to cooperative NOMA, as well as the interplay between NOMA and cognitive radio. This article also reviews the state of the art in the standardization activities concerning the implementation of NOMA in LTE and 5G networks.