Relay Selection based on Bayesian Decision Theory in Cooperative Wireless Networks

In cooperative wireless networks, proper relay selection is needed for assuring maximum diversity gain. In other words, user relaying helps to improve the transmission performance in wireless multiuser scenario by allowing each user to cooperate with each other and acts as a MIMO system by sharing their antennas in a timely and distributed way. Among several challenges in such networks, this paper focuses on the selection problem of relay node, and then we propose a scheme to select relay nodes by using Bayes theory. In this schema, at first each source node calculates prior and class conditional probability based on the channel state information and then relay nodes are selected based on the posterior probability of each source and relay node pair, which is estimated by applying Bayes theorem. The proposed relay assignment schema maximizes the overall data rate of the networks and it works well independent of the number of relay nodes or source-destination pairs in the network.