Optimal throughput-diversity-delay tradeoff in MIMO ARQ block-fading channels

Allen Chuang*, Albert Guillén i Fàbregas, Lars K. Rasmussen, Iain B. Collings

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)


In this paper, we consider an automatic-repeat-request (ARQ) retransmission protocol signaling over a block-fading multiple-input-multiple-output (MIMO) channel. Unlike previous work, we allow for multiple fading blocks within each transmission (ARQ round), and we constrain the transmitter to fixed rate codes constructed over complex signal constellations. In particular, we examine the general case of average input-power-constrained constellations with a fixed signaling alphabet of finite cardinality. This scenario is a suitable model for practical wireless communications systems employing orthogonal frequency division multiplexing (OFDM) techniques over a MIMO ARQ channel. Two cases of fading dynamics are considered, namely, short-term static fading where channel fading gains change randomly for each ARQ round, and long-term static fading where channel fading gains remain constant over all ARQ rounds pertaining to a given message. As our main result, we prove that for the block-fading MIMO ARQ channel with a fixed signaling alphabet satisfying a short-term power constraint, the optimal signal-to-noise ratio (SNR) exponent is given by a modified Singleton bound, relating all the system parameters. To demonstrate the practical significance of the theoretical analysis, we present numerical results showing that practical Singleton-bound-achieving maximum distance separable codes achieve the optimal SNR exponent.

Original languageEnglish
Pages (from-to)3968-3986
Number of pages19
JournalIEEE Transactions on Information Theory
Issue number9
Publication statusPublished - 2008
Externally publishedYes


  • Automatic-repeat-request (ARQ) retransmission protocols
  • Block-fading channels
  • Complex signal constellations
  • Incremental redundancy coding
  • Multiple-input-multiple output (MIMO) channels
  • Throughput-diversity-delay tradeoff


Dive into the research topics of 'Optimal throughput-diversity-delay tradeoff in MIMO ARQ block-fading channels'. Together they form a unique fingerprint.

Cite this