Channel-hole based scheduling in relay-assisted wireless networks

Abstract

Relay technologies are capable to significantly improve network performances in terms of cell capacity, coverage extension and system throughput. However, it should rely on an efficient scheduling scheme to fully profit from this potential gain. Although opportunistic scheduling is considered as the most promising scheduling technology for future networks in many literatures, it is not appropriate for the relay-assisted wireless systems due to some special features of the relay mode. In addition, most of the current literatures only discuss the scheduling in Base Station (BS) and neglect the channel state asymmetry between the BS-RS (Relay Station) link and RS-MS (Mobile Station) link. So we argue that an appropriate scheduling in RS can extremely improve the performance of the system. In this paper, we define a new concept called “channel-hole” which is used to precisely measure the wasted subchannel resources caused by the channel state asymmetry, and then propose a new scheduling algorithm, namely channel-hole based scheduling, in the RS based on this new concept. We also propose a theoretical model to analyze the proposed scheduling. Simulation results show that our proposed channel-hole scheduling is capable to utilize the radio resource more efficiently compared to the case where an opportunistic scheduling is used at the RS.