A Novel Multi-Relay Selection and Power Allocation Optimization Scheme in Cooperative Networks

Cooperative communication is an emerging and effective technology which can overcome the limitation and improve overall system performance of wireless networks. As important design parameters, relay selection, power and bandwidth allocation have been investigated respectively in previous literature. However, most of the existing schemes mainly consider single-relay selection, which may result in imbalance of resource utilization, and moreover, the "emergence" diversity gain among multiple relays cannot be achieved. In this paper, we propose a novel multi-relay nodes selection strategy, taking both instantaneous channel state information (I-CSI) and remaining energy as weighted metrics. Besides, an optimal power allocation algorithm using convex optimization method is presented. Theoretical analysis and simulation results show that the proposed scheme can significantly improve energy efficiency and channel capacity while maintaining relatively low implementation complexity in wireless cooperative relay networks.