Liao, RuizhiBellalta, BorisOliver Riera, MiquelNiu, Zhisheng2020-04-092020-04-092016Liao R, Bellalta B, Oliver M, Niu Z. MU-MIMO MAC protocols for wireless local area networks: a survey. IEEE Communications Surveys and Tutorials. 2014 Dec 4;18(1):162-83. DOI: 10.1109/COMST.2014.23773731553-877Xhttp://hdl.handle.net/10230/44197As wireless devices boom and bandwidth-hungry applications (e.g., video and cloud uploading) get popular, today's wireless local area networks (WLANs) become not only crowded but also stressed at throughput. Multiuser multiple-input-multiple-output (MU-MIMO), an advanced form of MIMO, has gained attention due to its huge potential in improving the performance of WLANs. This paper surveys random access-based medium access control (MAC) protocols for MU-MIMO-enabled WLANs. It first provides background information about the evolution and the fundamental MAC schemes of IEEE 802.11 Standards and Amendments, and then identifies the key requirements of designing MU-MIMO MAC protocols for WLANs. After this, the most representative MU-MIMO MAC proposals in the literature are overviewed by benchmarking their MAC procedures and examining the key components, such as the channel state information acquisition, decoding/precoding, and scheduling schemes. Classifications and discussions on important findings of the surveyed MAC protocols are provided, based on which, the research challenges for designing effective MU-MIMO MAC protocols, as well as the envisaged MAC's role in the future heterogeneous networks, are highlighted.application/pdfeng© 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. http://dx.doi.org/10.1109/COMST.2014.2377373info:eu-repo/semantics/articlehttp://dx.doi.org/10.1109/COMST.2014.2377373MACMU-MIMOIEEE 802.11WLANsMUDMUICCSISchedulinginfo:eu-repo/semantics/openAccess