Capacity maximization and transmission rates optimization for relay assisted wireless multicast

In this letter, we maximize the multicast capacity of a cellular system with dedicated decode-and-forward (DF) relays, by jointly optimizing transmission data rates of the base station (BS) and the relays subject to an average outage constraint in Rayleigh fading channels. The optimal transmission rates of the BS and relays and the optimal relay locations are obtained based on an outage probability analysis for the relay-assisted multicast. Numerical results show that relay-aided multicast significantly outperforms direct multicast, and the best transmission strategy is for the BS and dedicated relays to transmit at the same rate.