Explicit vs. implicit feedback for SU and MU-MIMO

Bruno Clerckx, Gil Kim, Junil Choi, Young Jun Hong

Research output: Chapter in Book/Report/Conference proceedingConference contribution

18 Citations (Scopus)


SU and MU-MIMO performance relies on accurate link adaptation in order to benefit from multi-user scheduling, beamforming, adaptive coding and modulation. Such accuracy highly depends on the type of the channel state information feedback. LTE-Advanced has defined two major types of feedback, i.e. implicit and explicit feedback. Implicit feedback makes some assumptions on the transmit precoding and receiver processing at the time of CSI and CQI feedback. The CSI is expressed in terms of a recommended precoder, commonly denoted as PMI. Explicit feedback refers to the feedback of channel information without making any assumption on the transmit and receiver processing. In this paper, we discuss pros and cons of such feedback mechanisms for both SU and MU-MIMO and compare performance of both approaches using system level simulations compliant with LTE-A system. It is shown that implicit feedback is the preferred feedback framework for both SU and MU-MIMO.

Original languageEnglish
Title of host publication2010 IEEE Global Telecommunications Conference, GLOBECOM 2010
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Print)9781424456383
Publication statusPublished - 2010
Event53rd IEEE Global Communications Conference, GLOBECOM 2010 - Miami, FL, United States
Duration: 2010 Dec 62010 Dec 10

Publication series

NameGLOBECOM - IEEE Global Telecommunications Conference


Other53rd IEEE Global Communications Conference, GLOBECOM 2010
Country/TerritoryUnited States
CityMiami, FL

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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