Cooperative Networks with Multiuser Diversity

In order to improve the diversity order of a cooperative network, this paper presents a new scheme which combines multiuser diversity with the amplify-and-forward protocol. We derive an asymptotic expression of the average symbol error rate (SER) to analyze the diversity order. Through the analysis and simulations, it is shown that the new scheme substantially improves the diversity order of a cooperative network. In addition, an optimal power allocation algorithm is proposed