A cross-layer adaptive transmission scheme combined with SR-ARQ over correlated fading channels
Current adaptive transmission schemes all assume independent block fading. However, in slow fading channels, it is highly possible for consecutive block transmissions to be correlated. In this paper, we propose a cross-layer adaptive transmission scheme, which is an optimum combination of modulation format and packet size, combined with selective repeat automatic repeat request (SR-ARQ) to improve the throughput in correlated slow fading channels. We apply it multi-state Markov system model to analyze the system performance and to optimize the selection of modulation levels at the physical layer and packet sizes at the data link layer in a correlated slow fading channel. which is also described by it finite-state Markov chain. A general closed-form expression of the average throughput for this cross-layer adaptive transmission scheme is presented. Simulation results show that our adaptive transmission scheme combined with SR-ARQ can obtain a good performance in correlated slow fading channels. (C) 2007 Elsevier Ltd. All rights reserved.
cross-layer correlated fading channel adaptive modulation adaptive packet size arq markov channel