Cooperative multicast transmission strategy for energy-efficient dynamic network coding

As a substantial means for improving throughput, network coding has recently attracted much attention to applying in wireless multicast services. To combat the channel fading of different users in a multicast group, the two-stage cooperative multicast is one of the most promising schemes. At the 1st stage, the users successfully receiving data from the base station can serve as relays to forward the data to the other users at the 2nd stage, which results in both system throughput and total energy consumption increased with the number of relays. To make the energy more efficient, the paper proposes an energy efficient cooperative multicast transmission scheme with dynamic network coding. In the proposed scheme, the selected relays at the 2nd stage are applying dynamic network coding. Then, the retransmission time can be saved and less energy will be consumed. Compared to minimum-SNR energy saving scheme and energy saving scheme with XOR, it is shown by simulation results that the proposed scheme can always achieve better energy efficiency for throughputs per energy consumption.