Alamouti-coded decode-and-forward protocol with optimum relay selection for cooperative communications

In this paper, we propose an Alamouti-coded decode-and-forward protocol with optimum relay selection for three-user one destination cooperative communications. The proposed scheme achieves the maximum diversity gain and lower probability of error in comparison with the existing decode and forward protocol with the optimum relay selection. The proposed scheme can also achieve more bandwidth efficiency from the optimum relay selection technique, and the cooperation criterion is based on the confidence of channel links. Moreover, in the performance analysis, an outage probability is studied and compared with the simulation results. Simulation results indicate that the proposed scheme significantly outperforms the existing protocols, and the theoretical outage probability curve is closed to the simulated SER curve.