Power and Subcarrier Allocation Strategies for Energy-Efficient Uplink OFDMA Systems

In this paper, we investigate computationally efficient strategies for energy-efficiency (EE) maximization in the uplink of a single-cell orthogonal frequency-division multiple-access system. We realize EE maximization by allocating power and subcarriers for each mobile station, and it has exponential complexity to achieve optimality. The Dinkelbach algorithm and Lagrange dual decomposition are well-established frameworks to solve the EE-maximization problem, but the definition of initial values and parameters remains an unresolved issue that is generally solved by empirical methods. To do this, we develop suitable procedures to efficiently calculate such values. We show that these procedures provide a very high EE, such that they can be systematized in two sub-optimal algorithms to efficiently allocate power and subcarriers without reliance on parameter-optimization problems.