Energy-efficient design for combined relay selection and power allocation AF-relay network

A wireless relay network is an effective communication scheme for energy efficient transmission. Further improvement of this scheme can be achieved by combining relay-selection and power-allocation strategies. In this paper, we consider a combined relay selection and power allocation approach under maximized output signal to noise ratio (SNR) to enhance the energy efficiency (EE) of a wireless amplify and forward relay network. With this strategy, the best relay is selected first and, then the optimal power for all nodes is allocated to optimize the EE. Simulation results show that the proposed model achieves better EE and throughput performance compared to models proposed in other studies. Further, a new model to examine the behavior between EE and spectrum efficiency (SE) has been proposed in this paper.