Opportunistic Cooperation with Node Selection Based on Power Allocation

Cooperative communication is an efficient technology to combat fading in wireless networks. In this paper, we propose an opportunistic cooperation algorithm with decode- and-forward strategy under a total power constraint. The relay selection and power allocation are jointly optimized to maximize the minimum of the weighted channel strengths between the links of source-relay and relay-destination in slow fading wireless channels. Our algorithm performs the power allocation between the source and the relay to decrease outage probability, and chooses a relay from multiple candidates with the knowledge of channel amplitude in two-hop scenario. Though the proposed algorithm is heuristic, numerical simulations show the advantages of this algorithm with the path loss and Rayleigh distributed fading.