A Guard-Band-Aware Channel Allocation Algorithm for Multi-Channel Cognitive Radio Networks

We consider the problem of channel allocation in cognitive radio network (CRN) with the restraints for adjacent-channel interference (ACI) caused by CRN, which is significant in the existing communication system and is easily ignored by researchers. In order to mitigate the effects of the adjacent-channel interference, it is a convenient way to use guard bands in CRN, when cognitive radio (CR) users dynamically exploit the idle spectrum owned by the primary user (PU). This paper focuses on a joint power control and channel assignment in a multi-channel CRN which realizes the use of spectrum effectively under the interference restrictions. Moreover, there are two important aspects of this guard bands method, which are the difference of primary networks and the operational mechanism of CRN, that we take into account. Since the optimization problem is, in general, NP-hard, we apply the coloring theory to reduce the complexity while providing the near-optimal performance. Finally, simulation results are provided, and the detailed numerical results are analyzed.