Energy-efficient power and subcarrier allocation in multiuser OFDMA networks

This paper addresses the energy-efficient resource allocation problem in downlink Orthogonal Frequency Division Multiple Access (OFDMA) networks with multiple users. The joint optimization of power and subcarrier allocation to maximize bits-per-Joule is formulated constrained by the maximum transmit power and the minimum required system data rate. Due to the prohibitive computational complexity, this paper proposes an iteration-based sub-optimal scheme with superlinear convergence based on the Dinkelbach method by relaxing the constraints and exploiting the properties of non-linear fractional programming. The analytical solutions for the power and subcar-rier allocation in each iteration are derived by the subgradient method according to Karush-Kuhn-Tucker (KKT) conditions and Lagrange multipliers. Finally, the simulation results validate the convergence and energy efficiency performance of the proposed scheme.