Media type: E-Article Title: Optimal User Grouping for Downlink NOMA Contributor: Kang, Jae-Mo; Kim, Il-Min Published: Institute of Electrical and Electronics Engineers (IEEE), 2018 Published in: IEEE Wireless Communications Letters, 7 (2018) 5, Seite 724-727 Language: Not determined DOI: 10.1109/lwc.2018.2815683 ISSN: 2162-2337; 2162-2345 Origination: Footnote: