Energy-efficient resource allocation in multiuser decode-and-forward relay networks

High energy consumption in networks is a key concern for the future wireless networks and hence, it has attracted increasing attention recently. In this work, we investigate joint source and relay transmit power allocation algorithm in a simple multiuser decode-and-forward (DF) relay network composed of multiple source, a relay and multiple destination, and focus on energy efficiency (EE) maximization which works as the critical performance evaluation metric for future communication systems. By taking into account the static power consumption, we first formulate EE maximization as a non-convex optimization problem. Then, we transform this non-convex problem into a convex optimization problem by utilizing successive convex approximation (SCA) and exploiting the properties of non-linear fractional programming approach. Consequently, an energy-efficient iterative power allocation algorithm is proposed to improve the EE and finally reach to a globally optimal solution. Through simulation results, the tradeoff between EE and the spectral efficiency (SE) is presented.