Multi-mode transmission for the MIMO broadcast channel with imperfect channel state information

Jun Zhang, M. Kountouris, J.G. Andrews, R.W. Heath Jr.

Research output: Journal article publicationJournal articleAcademic researchpeer-review

100 Citations (Scopus)

Abstract

This paper proposes an adaptive multi-mode transmission strategy to improve the spectral efficiency achieved in the multiple-input multiple-output (MIMO) broadcast channel with delayed and quantized channel state information. The adaptive strategy adjusts the number of active users, denoted as the transmission mode, to balance transmit array gain, spatial division multiplexing gain, and residual inter-user interference. Accurate closed-form approximations are derived for the achievable rates for different modes, which help identify the active mode that maximizes the average sum throughput for given feedback delay and channel quantization error. The proposed transmission strategy can be easily combined with round-robin scheduling to serve a large number of users. As instantaneous channel information is not exploited, the proposed algorithm cannot provide multiuser diversity gain, but it is still able to provide throughput gain over single-user MIMO at moderate signal-to-noise ratio. In addition, it has a light feedback overhead and only requires feedback of instantaneous channel state information from a small number of users. In the system with a feedback load constraint, it is shown that the proposed algorithm provides performance close to that achieved by opportunistic scheduling with instantaneous feedback from a large number of users. © 2011 IEEE.
Original languageEnglish
Article number5671564
Pages (from-to)803-814
Number of pages12
JournalIEEE Transactions on Communications
Volume59
Issue number3
DOIs
Publication statusPublished - 1 Mar 2011
Externally publishedYes

Keywords

  • broadcast channels
  • delay effects
  • feedback
  • MIMO systems
  • space division multiplexing

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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