In this paper, an Alamouti-coded decode-And-forward protocol with optimum relay selection for three-user one

destination cooperative communications is investigated. Particularly, we design the new protocol that allows the

source node retransmitting the signal to the destination node at the same time as the relay node forwarding the

received signal to the destination node with an Alamouti coding scheme. We exploit the cooperative maximum

ratio combining technique (C-MRC) at the destination for combining a multiple copy of received signals.