Adaptive multicast scheme for OFDMA-based multicast wireless systems using layered coding

In conventional multicast scheme (CMS), the total throughput of multicast group is constrained by the user with the worst channel quality. In order to overcome this problem of limited throughput, we consider a resource allocation algorithm based on layered coding, when a limited feedback scheme is considered. A novel subcarrier and power algorithm is exploited for targeting the maximum throughput (MT) of enhancement layers while at the same time guaranteeing the quality of services (QoS) requirements of all users. In this paper, a three-step subcarrier allocation algorithm and two power allocation algorithms are proposed. Simulation results show that the proposed algorithm significantly outperforms CMS. Moreover, it obtains more throughput than another existing algorithm.