Optimum ARQ design: a dynamic programming approach

A hybrid ARQ scheme as an incremental accumulation of redundancy at the receiver is viewed in this article. A hybrid ARQ design problem is formulated as a search for the sequence of redundancies maximizing throughput or minimizing delay. The optimization is performed within the framework of a Markov decision process. The state space is defined as the total accumulated redundancy at the receiver. The transition probabilities model the error-correcting capability of the code and properties of the channel. Employing a dynamic programming approach, the optimum sequence of redundancies is characterized.