Opportunistic Multicast Scheduling with Erasure-Correction Coding over Wireless Channels

This paper proposes an opportunistic multicast scheduling scheme using erasure-correction coding to jointly explore the multicast gain and multiuser diversity. The proposed scheme sends only one copy to all users in the multicast group at a transmission rate based on a SNR threshold selected using only the knowledge of the average SNR and fading type of the fading environment. Analytical framework is developed to establish the optimum selection of the SNR threshold and coding rate for given channel conditions in a Nakagami-m fading environment to achieve the best throughput. Numerical results show that the proposed scheme outperforms both the worst-user (WU) and best-user (BU) schemes for a wide range of average SNR and multicast group size. Without the requirement for perfect knowledge of the instantaneous user channel responses, the proposed scheme can significantly reduce the overhead required for channel information feedback and is suitable for a fast time-varying fading environment. Another advantage of the proposed scheme is that its achievable normalized throughput is independent of the multicast group size.