Opportunistic scheduling of delay sensitive traffic in OFDMA-based wireless networks

OFDMA is an attractive multiple access technique for packet-based mobile broadband wireless access for beyond 3G and 4G systems. Radio resource allocation in OFDMA can exploit multiuser diversity to increase system capacity by implementing opportunistic scheduling techniques. This paper presents a new opportunistic scheduling scheme for OFDMA-based wireless multimedia networks. We focus the scheduling algorithm on the class of delay-sensitive packets that belong to interactive applications such as telephony and video streaming. We divide the scheduling decision into two sub-problems: the OFDMA subcarrier allocation and subsequently the subcarrier assignment. Both the sub-carrier allocation and assignment algorithms exploit multiuser diversity and are designed to provide fairness with respect to the realizable throughput per user, packet dropping ratios and packet delay distributions. We investigate various performance aspects of the proposed scheduling algorithm using actual MPEG-4 traffic traces under different system loading and requested deadline values. The results show the superiority of the proposed scheduling scheme and its excellent performance with respect to throughput, packet dropping, and delay distributions