Local Interference Coordination in Cellular OFDMA Networks

Orthogonal Frequency Division Multiple Access (OFDMA) is a promising concept, which is the basis of the currently emerging 802.16e (WiMax) and 3GPP Long Term Evolution (LTE) cellular systems. OFDMA is basically a combination of FDM and TDM, and therefore suffers from heavy inter-cell interference if neighboring basestations use the same frequency range. However, it is desirable to reuse the complete available frequency spectrum in every cell in order to maximize the resource utilization. One approach to solve this conflict is the application of beamforming antennas in combination with interference coordination mechanisms between basestations. Starting from a global interference coordination scheme with full system knowledge, we investigate how spatially limited interference coordination affects the system performance. Subsequently, we study several realizable interference coordination schemes and show that a locally implementable scheme can almost match the performance of the global scheme with respect to the sector throughput.