QoS Based Performance Evaluation for the Cooperative Communication Systems in Decode-and-Forward Mode

This work considers the cooperative communication systems in Decode-and-Forward Mode. The scenario includes one source station, M relay stations and N destinations. In order to meet Quality of Service (QoS) guarantee, the individual capacity between the source station and the destination is considered under the worst case. However, for the whole system, the maximum throughput approaching is the major purpose in this work. Hence, to select the relay stations for signal transmission could be the important scheme to achieve the best system performance. Based on the exhaustive search method, easily to realize, the optimal selection scheme can be found with a highly complicated calculation. In order to reduce the computational complexity, a solution with a greedy algorithm applied to the relay selection scheme is proposed. With different situations of the communication systems, the performances evaluations obtained by both the proposed method and the exhaustive search method are given for comparison. It shows the proposed algorithm could provide a solution approaches to the optimal one. It is better to apply the proposed scheme when the number of relay stations is much larger than that of destination stations.