Hybrid Energy Supply based Energy Efficiency and Spectral Efficiency Tradeoff for Green Cellular System

The tradeoff between energy efficiency (EE) and spectral efficiency (SE) under the smart grid with joint energy harvesting and grid power supply is considered. The price factor in economics is used to propose the economic EE and SE. Then a new EE-SE tradeoff metric called the EE-SE adaptive tradeoff (ESAT) is built under the fluctuating harvesting energy. Furthermore, the offline optimization problem is put forward and the solution is discussed. The offline solutions based on the branch-and-bound algorithm and the Lagrange dual decomposition method are discussed to analyze the influence of renewable energy quantity on the proposed structure. Numerical results indicate that the proposed ESAT framework is efficient to the tradeoff between EE and SE.