A Novel Centralized Resource Scheduling Scheme in OFDMA-Based Two-Hop Relay-Enhanced Cellular Systems

OFDMA-based relay-enhanced cellular systems have been proposed as a promising solution for the next-generation wireless communications. The deployment of relay stations (RS) in cellular networks makes resource scheduling a more crucial and challenging task. In this paper, a novel centralized scheduling scheme called centralized scheduling with void filling (CS-VF) is proposed for two-hop relay-enhanced networks. In CS-VF, the remaining slots in the RS-subframe are filled with packets destined to users who directly communicate with the base station (BS). Moreover, based on our CS-VF scheduling scheme, four representative single-hop scheduling algorithms: round-robin, max C/I, max-min fairness, and proportional fairness, are extended to multihop scenarios. Simulation results indicate that when compared with the existing centralized scheduling scheme, which does not consider void filling, our proposed CS-VF scheme is more adaptable to different traffic distributions caused by dynamic network topology and user mobility. And it enhances not only the system throughput but also the fairness among users.