Error Control Strategies for WiMAX Multi-Hop Relay Networks

Next generation wireless system such as advanced WiMAX (i.e., IEEE802.16m) and LTE advanced will fully embrace multi-hop relay architecture. The conventional Automatic Repeat reQuest (ARQ) and the more recent Hybrid ARQ (HARQ) are two simple yet highly effective error control techniques designed for single hop system. Nevertheless, extending them in a synergistic manner to support multi-hop relay networks is by no means a trivial undertaking. This paper explores a variety of multi-hop error control techniques such as hop-by-hop ARQ, 2-link ARQ and end-to-end ARQ, and various possible combinations with HARQ. We further establish an analytical framework for each of these key techniques and evaluate the performance. Based on the analysis and comparison, we propose a low complexity error control mechanism tailored for the multihop transmission features. Extensive simulation results compare the performance and validate our analytical framework.