Relay Selection and Power Control for Energy-Efficient Cooperative Multicast Communication

In this paper, we investigate the two-phase cooperative multicast communication, where a base station broadcasts the same information to a group of users in the first phase and then some successful users act as relay to help the failed users in the second phase. To maximize the energy efficiency of the cooperative multicast communication, we propose a probability-based relay selection and power control method. With our method, each successful user may autonomously decide whether to conduct the relay for the failed users and also select the proper transmission power for the relay transmission. In particular, the proposed method does not require any handshake either between base station and users, or among users. Simulation results demonstrate that our method obtains almost the same performance as the optimal relay selection and power control method with exhaustive search.