Cluster-based cooperative communications and relay selection in wireless networks

In the conventional dual-hop cooperative communications, the relays with imbalanced channel gain to the source and the destination cannot be efficiently utilized since one of these two hops can become the bottleneck of the overall transmission. In this paper, we propose a cluster-based cooperative communication (CBCC) scheme to address this problem. In this scheme, relays are divided into two clusters, and the cooperative transmissions consist of three stages. In this way, the bottleneck between the relay and the source or the destination can be potentially broken through the relay-to-relay transmissions. We focus on the relay selection problem for this cluster-based cooperation scheme, which turns out to be difficult due to the coupling of the relays between two clusters. We then resort to the design of heuristic algorithm and provide simulation results to show the performance of the proposed scheme.