A graph approach for coordinated channel allocation in downlink multi-cell OFDMA networks

Radio resource allocation in multi-cell OFDMA (orthogonal frequency-division multiple access) networks is a challenging and practically important problem. In this work we propose a new graph-based sub-channel assignment scheme for downlink multi-cell OFDMA networks. Our scheme consists of two phases, both of which are formulated as graph problems. The first phase is location-aware interference management, including inter-cell interference coordination (IOC) as well as intra-cell interference avoidance. The second phase is channel-aware sub-channel assignment. Simulation results demonstrate that the proposed scheme significantly enhances the system throughput while maintaining user-Quality of Service (QoS) compared with existing sub-channel assignment schemes.