Stable Transmission in the Time-Varying MIMO Broadcast Channel

Abstract

Both linear and nonlinear transmit precoding strategies based on accurate channel state information (CSI) can significantly increase available throughput in a multiuser wireless system. With propagation delay, infrequent channel updates, lag due to network layer overhead, and time-varying node position or environment characteristics, channel knowledge becomes outdated and CSI-based transmission schemes can experience severe performance degradation. This paper studies the performance of precoding techniques for the multiuser broadcast channel with outdated CSI at the transmitter. Traditional channel models as well as channel realizations measured by a wideband channel sounder are used in the analysis. With measured data from an outdoor urban environment, it is further shown the existence of stable subspaces upon which transmission is possible without any instantaneous CSI at the transmitter. Such transmissions allow for consistent performance curves at the cost of initial suboptimality compared to CSI-based schemes.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2008
Accession Number
ADA506493

Entities

People

  • Adam L. Anderson
  • James R. Zeidler
  • Michael A. Jensen

Organizations

  • University of California, San Diego

Tags

DTIC Thesaurus Topics

  • Algorithms
  • Beam Forming
  • Channel Estimation
  • Channel Models
  • Channel State Information
  • Computers
  • Engineering
  • Frequency
  • Measurement
  • Mobile Ad Hoc Networks
  • Mobile Phones
  • Multiple Access
  • Multiple Input Multiple Output
  • Signal Processing
  • Simulations
  • Standards
  • Time Division Multiple Access

Fields of Study

  • Engineering

Readers

  • Radio communications and signal processing.