Multiple-relay selection scheme in amplify-and-forward cooperative system

A multiple relay selection scheme in amplify-and-forward cooperation system was proposed. The proposed scheme can find the best relays which optimize the tradeoff function between SNR and power consumed according to the different requirement of the system. At the same time it can effectively reduce the complexity of the scheme. A predetermined cooperative threshold is given to obtain a candidate relay set. In the set we can find the best relays to optimize the function which tradeoff the SNR and the power consumed. Simulation results show that our scheme can reduce the power consumed while satisfying the same block error rate if we choose the suitable value of the parameter.