Hybrid ARQ in Multiple-Antenna Slow Fading Channels: Performance Limits and Optimal Linear Dispersion Code Design

TL;DR

This paper investigates the fundamental performance limits of MIMO-ARQ slow fading channels, analyzing optimal rate strategies and designing space-time codes to enhance reliability and throughput in such wireless systems.

Contribution

It introduces a new design criterion for space-time codes based on error probability analysis and evaluates the benefits of ARQ feedback in MIMO systems.

Findings

Optimal average rate of HARQ protocols is characterized.

A new design criterion for space-time codes is proposed.

ARQ feedback provides significant performance gains.

Abstract

This paper focuses on studying the fundamental performance limits and linear dispersion code design for the MIMO-ARQ slow fading channel. Optimal average rate of well-known HARQ protocols is analyzed. The optimal design of space-time coding for the MIMO-ARQ channel is discussed. Information-theoretic measures are used to optimize the rate assignment and derive the optimum design criterion, which is then used to evaluate the optimality of existing space-time codes. A different design criterion, which is obtained from the error probability analysis of space-time coded MIMO-HARQ, is presented. Examples are studied to reveal the gain of ARQ feedback in space-time coded MIMO systems.