New approach for error compensation in coded V-BLAST OFDM systems

Heunchul Lee, Inkyu Lee

Research output: Contribution to journalArticle

68 Citations (Scopus)

Abstract

In this paper, we investigate coded layered space-time architectures for frequency-selective fading multiple-input multiple-output orthogonal frequency-division multiplexing (OFDM) channels. By computing outage capacity formulas, we will show that the capacity of the vertical Bell Labs layered space-time (V-BLAST) architecture can closely approach the Shannon capacity in the frequency-selective OFDM environment. Motivated by the capacity analysis, we propose pragmatic approaches which preserve the optimality of the layered space-time concept. We present methods to prevent the error propagation from catastrophically affecting the signal detection in subsequent layers. First, we start with a comprehensive signal modeling which includes error propagation. We derive an improved signal detector and describe the optimal soft-bit log-likelihood ratio value-computation method by taking decision errors into account for soft-input channel decoding. Then, to further enhance the V-BLAST performance, we show that cancellation using decoded decisions from previous layers makes the decision errors almost completely disappear, so that the layered space-time architecture can approach the attainable channel capacity. Finally, simulations confirm that the proposed schemes show a significant performance improvement over the conventional methods.

Original languageEnglish
Pages (from-to)345-355
Number of pages11
JournalIEEE Transactions on Communications
Volume55
Issue number2
DOIs
Publication statusPublished - 2007 Feb

Keywords

  • Error compensation
  • Multiple-input multiple-output (MIMO) systems
  • Orthogonal frequency-division multiplexing (OFDM)
  • Vertical Bell Labs layered space-time (V-BLAST)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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