Optimal Power Allocation of Energy Efficiency for Cognitive Relaying Networks with Nakagami-m Fading Channels

Energy efficiency optimization of wireless communication systems has attracted increasing attention recently due to its beneficial impacts on the environment and operational savings. In this work, we present a power allocation framework for cognitive relaying networks based on maximizing the energy efficiency (EE). First, we show that the relation between the EE and the spectral efficiency (SE) is strictly increasing in single user communication system. In addition, we solve a nonconvex problem and explicitly derive the optimal power for the proposed average energy efficiency under peak transmit power and peak interference power constraints. Finally, we apply our results to the cognitive relaying networks, in which the power is limited by an interference constraint with Nakagami-m fading channels. Simulation results show that optimal power allocation can significant improving energy efficiency of cognitive relaying networks.