Interference Mitigation in Two-Tier OFDMA Femtocell Networks: A Potential Game Approach

The problem of interference mitigation in two-tier downlink orthogonal frequency division multiple access (OFDMA) femtocell networks is considered in this paper. We propose a potential game based distributed power control algorithm, aiming at maximizing the users' SINRs and improving the system capacity. With a penalty factor in system capacity as a utility function for macrocell and femtocell, a global optimization problem then turns into a local optimization problem with multiiterations. Based on gradient projection response criterion, dynamically rational power allocation for each resource block is performed, achieving the coordination of interference between macrocell and femtocell and increasing system capacity. Simulation results show that the proposed scheme effectively reduces the system capacity loss and improves the throughput of macrocell users with minor performance degradation of the femtocell users. Moreover, the proposed scheme is easy to implement in a decentralized manner.