Cooperative Non-Orthogonal Multiple Access in Multiple- Input-Multiple-Output Channels

DOI number:10.1109/TWC.2017.2788413

Journal:IEEE Transactions on Wireless Communications

Abstract:Cooperative non-orthogonal multiple access (NOMA) systems inherit advantages of the NOMA protocol and the cooperative relay. In this paper, we propose cooperative NOMA systems in multiple-input-multiple-output channels. The whole transmission is divided into two phases. In the first phase, the base station broadcasts signals using the NOMA protocol to a central user and a cell-edge user. In the second phase, the central user helps the base station cooperatively relay signals intended for the cell-edge user. Our objective is to maximize achievable rate from the base station to the cell-edge user under transmit power constraints and achievable rate constraint from the base station to the central user. The difficulty of this problem is the joint beamforming of the base station and the central user in the second phase. We propose a constrained convex-concave procedure (CCCP)-based algorithm. To reduce computational complexity, we also propose a closed-form search-based suboptimal algorithm. Simulation results demonstrate that our proposed cooperative NOMA system with CCCP-based algorithm outperforms the conventional NOMA scheme. When achievable rate constraint to the central user is low, our proposed cooperative NOMA system with the closed-form search-based suboptimal algorithm outperforms the NOMA scheme.

Co-author:jmiao,李全忠,秦家银

First Author:Li Yiqing

Indexed by:Journal paper

Correspondence Author:张旗

Discipline:Engineering

First-Level Discipline:Information and Communication Engineering

Document Type:J

Volume:17

Issue:3

Page Number:2068–2079

ISSN No.:1558-2248

Translation or Not:no

Date of Publication:2018-03-01

Included Journals:SCI

Links to published journals:https://ieeexplore.ieee.org/document/8247238