An Energy Efficient Cooperative Multicast Transmission Scheme with Power Control.

The two-stage cooperative multicast transmission is a promising scheme to combat the channel fading of different users in a multicast group, where the users successfully receiving data at the 1st stage can serve as relays to forward the data to the rest of users at the 2nd stage. Both the system throughput and total energy consumption increase with the number of relays. To obtain a balance between the system throughput and energy consumption, this paper proposes an energy efficient cooperative multicast transmission scheme with power control. In the proposed scheme, the number of relays used at the 2nd stage is limited by constraining the total power consumption. Then, the preferred relays are chosen according to a minimum-SNR (Signal-to-Noise Ratio) criterion. It is shown by simulations that compared to previous cooperative multicast transmission, the proposed scheme achieves a flexible tradeoff between the system throughput and energy consumption by controlling the total available power. Moreover, it can always achieve better energy efficiency than the existing cooperative and conventional multicast schemes in terms of throughput per energy consumption.