Sense in order: Channel selection for sensing in cognitive radio networks

This paper considers a pre-phase of spectrum sensing in cognitive radio networks (CRNs), which is about how to choose a channel for spectrum sensing. We take the time dimension, spectrum dimension, and spacial dimension into account and propose a sense-in-order model. In this model, each node maintains four states regarding each channel, based on the neighbors´ shared information. We construct a state transition diagram for the four states and design an algorithm for every node to calculate the probability of choosing each channel. Moreover, we extend our model by introducing the angle dimension into the sense-in-order (SIO) model. In the extended model, each node is equipped with a four-directional antenna, which creates more channel opportunities. We describe the problem that is brought about by directional antennas, and propose a weight-based solution for each node to determine the channel state in each direction. Extensive simulation results testify for the performance of our model.