Scaling multi-user MIMO WLANs: The case for concurrent uplink control messages

Oscar Bejarano, Sadia Quadri, Omer Gurewitz, Edward W. Knightly

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

4 Scopus citations

Abstract

Downlink Multi-User MIMO (MU-MIMO) enables the simultaneous spatial sharing of the channel by multiple users to achieve a capacity gain over Single-Input Single-Output (SISO) systems. Unfortunately, the overhead required to enable multi-user MIMO is much higher than the overhead required for single-stream systems. Namely, for K users, collection of channel state information requires K transmission exchanges (i.e., O(K)) between the AP and users. Likewise, the MU-MIMO acknowledgement process also requires the same amount of exchanges, thus reducing the performance gains attained via simultaneous downlink transmission. In this paper, we design, implement, and experimentally evaluate Concurrent Uplink Control Messages (CUiC) to scale the MU-MIMO control information exchange process and improve the efficiency of 802.11ac-based MU-MIMO networks. Our key technique is the design of new channel sounding and acknowledgement mechanisms that enable multiple users to transmit their reverse-direction control messages (i.e., beamforming reports and acknowledgments) concurrently to the AP, in O(1) transmission slots. We implement CUiC and perform an extensive set of experiments and demonstrate throughput gains of more than 100% compared to 802.11ac.

Original languageEnglish
Title of host publication2015 12th Annual IEEE International Conference on Sensing, Communication, and Networking, SECON 2015
PublisherInstitute of Electrical and Electronics Engineers
Pages238-246
Number of pages9
ISBN (Electronic)9781467373319
DOIs
StatePublished - 25 Nov 2015
Event12th Annual IEEE International Conference on Sensing, Communication, and Networking, SECON 2015 - Seattle, United States
Duration: 22 Jun 201525 Jun 2015

Publication series

Name2015 12th Annual IEEE International Conference on Sensing, Communication, and Networking, SECON 2015

Conference

Conference12th Annual IEEE International Conference on Sensing, Communication, and Networking, SECON 2015
Country/TerritoryUnited States
CitySeattle
Period22/06/1525/06/15

Keywords

  • Array signal processing
  • Channel estimation
  • Downlink
  • Interference
  • MIMO
  • Timing
  • Uplink

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Instrumentation

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