Group buying spectrum auction algorithm for fractional frequency reuse cognitive cellular systems

Fractional frequency reuse (FFR) can not only coordinate inter-cell interference (ICI), but also improve communication quality of cell-edge users, whose key idea is to make a tradeoff between frequency utilization efficiency improvement and ICI suppression. In terms of the fact that conventional spectrum auction neglects the inter-cell and intra-cell interference and wireless spectrum has become scarce resources in cognitive radio networks, in this paper, FFR technology is introduced into the field of spectrum auction and a group reuse spectrum auction mechanism for FFR (GRSAF) is proposed in cognitive cellular systems to achieve higher spectrum allocation and usage efficiency. A Lagrangian relaxation (LR) algorithm is developed to solve the optimal sum utility maximization spectrum allocation problem. Simulation results show that the GRSAF mechanism can significantly improve the sum utility, spectrum reusability as well as satisfaction degree of buyers compared with other two existing auction mechanisms.