Radio Resource Allocation for Interference Management in OFDMA-Based Femtocell-Macrocell Deployment

In this paper, we consider a downlink resource allocation in an Orthogonal Frequency Division Multiple Access (OFDMA) based heterogonous cellular network. In order to use spectrum efficiently, we propose Non-Exclusive Spectrum Allocation scheme (NESA). The considered objective function of the NESA scheme is to maximize the sum rate of macrocell and femtocells subject to maximum transmit power and maximum acceptable interference from femtocells on Macrocell User Equipments (MUEs) constraints. To solve the proposed non convex optimization problems, we divide the corresponding problems into two sub-optimal problems including sub carriers allocation and power allocation. We then consider a lower bound on the objective function corresponding to the sub-problem of power allocation for femtocells and transform it into a convex problem. This problem is solved based on an iterative algorithm. Presented simulation results validate the accuracy of the developed scenario.