Resource Minimization for Hybrid ARQ System with Real-Time Traffic in Time-Correlated Rayleigh Fading Channels

Most studies on hybrid automatic repeat request (HARQ) with respect to rate adaptation have been focused on throughput maximization. However, for real-time traffic, resource minimization is a more efficient rate adaptation method in OFDMA-based systems. Moreover, most previous work have dealt with either slow or fast fading channel although practical wireless channels typically exhibit a time-correlated property. In this paper, we analyze the outage probability and average resource usage of HARQ with rate adaptation in a time-correlated channel model. Then, we propose a rate adaptation scheme to minimize the average resource usage and evaluate the performance of the proposed scheme under delay and packet loss constraints of real-time traffic. Our analytical and numerical results show that the proposed rate adaptation scheme is more efficient than the conventional schemes.