Cooperative Interference Control for Spectrum Sharing in OFDMA Cellular Systems

This paper studies the cooperative interference control in a two-cell downlink OFDMA system, which can be modeled as an interfering broadcast channel. It is assumed that each cell can simultaneously access the same frequency band, which corresponds to a universal frequency-reuse in cellular systems. We study the joint power and subcarrier allocation over the two cells to maximize their sum throughput for both centralized and decentralized implementation. Specifically, the decentralized allocation is achieved via a new interactive interference control approach, where the two cells independently implement resource allocation to maximize individual throughput, subject to mutual interference power constraints. Simulation results show that the proposed decentralized resource allocation scheme achieves the system throughput close to that with the optimal centralized scheme, and also provides significant gains via cooperative interference control as compared to existing schemes.