Optimal power allocation and relay selection in dual-hop and multi-hop cognitive networks

In this paper, we consider a cognitive relay network which contains a source node, a destination node and a group of network clusters each consisting of several cognitive relay nodes. We choose one relay node with the optimal power value in each cluster to aid the data transmission from source to destination, with the goals of minimizing the total transmitting power and maximizing the network capacity under outage and interference constraints. The research is based on a dual-hop scenario and a multi-hop scenario. The proposed schemes achieve the optimal power allocation and efficient relay selection in both scenarios. The closed-form optimal power allocation and relay selection for a conventional relay network are also listed in this paper.