Energy-efficient resource allocation and power control for downlink multi-cell OFDMA networks

In this paper, we propose an energy-efficient joint resource allocation and power control scheme for downlink multi-cell orthogonal frequency division multiple access (OFDMA) networks with imperfect channel state information (CSI). Considering the maximum allowed transmit power, the tolerable outage probability, and the fact that each resource block is allocated to at most one user in each cell, we formulate the energy-efficient joint resource allocation and power control problem as a probabilistic mixed non-convex fractional programming problem, which is hard to be tackled. In order to solve the problem efficiently, we first substitute the probabilistic constraints into the objective function and then introduce new auxiliary variables to transform the original problem into a difference of two convex functions (D.C.) programming problem. As a result, we resort to D.C. algorithm to obtain a solution satisfying Karush-Kuhn-Tucker conditions of the D.C. problem. Simulation results are presented to demonstrate the effectiveness of the proposed scheme.