A novel clustering scheme for spectrum sharing in multi-hop ad hoc Cognitive Radio Networks

In this paper, we propose a novel clustering scheme to efficiently manage the spectrum identification and exploitation in multi-hop ad hoc Cognitive Radio Networks (CRNs). We cluster the Secondary Users (SUs) based on their geographical locations and occurring orders. Using spread spectrum techniques with different spreading codes for different clusters, one global Common Control Channel (CCC) for the whole secondary network can be facilitated and the co-channel interference between the adjacent clusters can be reduced. The proposed clustering scheme allows the SUs to initiate and maintain the clusters reliably with signaling inherent in the Medium Access Control (MAC) framework; moreover, the SUs in each cluster can benefit from all the available spectrum for concurrent transmissions without affecting other users in the adjacent clusters.