Topology Control With Successive Interference Cancellation in Cognitive Radio Networks

Topology control is an important approach to maintain the connectivity of cognitive radio networks (CRNs). Most existing works assumed that secondary users (SUs) must vacate the spectrum reclaimed by primary users (PUs), resulting the inefficient spectrum utilization. In this paper, we consider the simultaneous transmissions of SUs with PUs; meanwhile, SUs are equipped with successive interference cancellation (SIC) to mitigate the interference from PUs, thereby enabling SUs to access the spectrum more aggressively than previous works. Although SIC has been studied in the information theory and signal processing, it is not well investigated in guaranteeing the connectivity of wireless networks, especially the CRNs. On this account, we propose both centralized and distributed SIC-based topology control algorithm to alleviate the impact of the unpredictable activities of PUs and the potential interference between SUs. In particular, we integrate power control with channel assignment to construct a bi-channel-connected and conflict-free CRN with the fewest required channels. Theoretical analysis reveals that the bi-channel-connectivity and conflict-free properties can be ensured by our proposed algorithms. Then, simulation results demonstrate the effectiveness of proposed algorithms in terms of reducing the number of required channels and improving the robustness of topologies, as compared with the prevailing topology control algorithms.