A Unified Energy Efficiency and Spectral Efficiency Tradeoff for Mobile Cloud Computing in OFDM-based Networks

Cloud computing can improve the computing ability of mobile terminals. However, offloading is not always energy-saving compared to local computation. To further improve the battery lifetime, tradeoff between energy efficiency (EE) and spectral efficiency (SE) in transmitting is considered, we propose a transmission strategy to decide whether to offloading or not. This strategy focuses on the EE-SE tradeoff to make more effective use of the limited resources. Compared to previous studies about the tradeoff between EE and SE, the objective of this paper treats EE and SE as one joint optimization function. We firstly prove the properties of the joint function in orthogonal frequency division multiplexing (OFDM)-based networks and derive its optimal solution, then apply this optimization strategy in cloud computing. Simulation results confirm the analytical properties and show the advantage of tradeoff scheme compared conditional design.