Adaptive multicast scheme for OFDMA based multicast wireless systems

An adaptive multicast scheme is proposed to overcome the spectral inefficiency problem of OFDMA (orthogonal frequency-division multiple access)-based multicast networks in the presence of high link quality differences among multicast users. The proposed scheme divides a multicast group into smaller sub-groups and subcarriers are allocated to maximise the aggregate data rate. Having smaller multicast groups allows multiuser diversity to be exploited more efficiently. Simulation results show that the proposed scheme can achieve near-optimal performance whilst outperforming the conventional unicast and multicast schemes.