On efficiency of link adaptation mechanisms in H/ARQ systems

Abstract

In this study we analyze the synergy effects among ARQ and Hybrid ARQ with rate-adaptive mechanisms. We present several coding and decoding schemes and link adaptation techniques for rate-adaptive transmission, designed to combat noise, and we discuss their performance. We describe approaches for searching and selecting the best modulation and coding scheme (MCS) based on channel quality information (CQI). Hybrid ARQ using convolutional and punctured convolutional codes is used with variable retransmission packet size and code rate according to CQI. Attractive simulation results are issued and they may be used as a basis for performance trade-off.