Hybrid ARQ schemes in multiple-antenna slow fading channels: A capacity perspective

Abstract

This paper studies Hybrid ARQ (HARQ) schemes in a multiple-antenna slow fading channel. Optimal average rate performance of several well-known HARQ protocols is analyzed. We then proceed to the design of Space-Time Coding (STC) for MIMO-HARQ channel. Information-theoretic performance measures are used to optimize the rate assignment and derive the optimum STC design criterion. Numerical comparisons are made to evaluate existing ST codes and illustrate the gain of MIMO-HARQ.