Impact of Channel Heterogeneity on Spectrum Sharing in Cognitive Radio Networks

Cognitive radio technology solves the spectrum under-utilization problem by enabling the secondary users access the spectrum holes opportunistically. Therefore, how to efficiently share the spectrum holes among the secondary users is of interest. Previous studies on spectrum sharing focused on the formulations with homogeneous channels. The channel heterogeneity, which is a unique feature in cognitive radio networks, has been ignored. In this paper, we consider heterogeneous channels and explore the impact of channel heterogeneity on the spectrum sharing. We model the channel heterogeneity, interference constraints and spectrum sharing, and formulate an optimization problem in the form of binary integer linear programming (BILP). To the best of our knowledge this is the first attempt to model the channel heterogeneity into the formulation of spectrum sharing in cognitive radio networks. Numerical results show that the optimal solution on spectrum sharing is highly dependent on the channel heterogeneity.