In recent years, Orthogonal Frequency Division Multiple Access (OFDMA) has become an attractive transmission technology, which is part of various emerging system standards for broadband cellular communications. Examples include the 3GPP Long Term Evolution (LTE) and 802.16e WiMAX. In OFDMA, mobile terminals are multiplexed in time and frequency. A major problem in these systems is the inter-cell interference, which is caused by neighboring cells when transmitting on the same time and frequency

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... lots. This problem can be solved by using beamforming antennas and coordinating the transmissions among base stations. This is known as interference coordination. In this paper, we present a distributed algorithm for interference coordination, which enhances the cell edge performance with global information provided by a central coordinator. The signaling delay during the communication with the central coordinator can be on the order of seconds, while an additional local interference coordination in each base station ensures a high performance even in dynamic environments. This combination of global and local coordination enhances the overall spectral efficiency as well as the cell edge performance compared to a Reuse 3 system.