Pre-phase Improvement For Distributed Spectrum 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. Extensive simulation results testify to the performance of our model. In addition, we conduct experiments on the USRP/Gnuradio testbed to prove the main part of the sense-in-order model with directional antennas. Experimental results show that the average success percentage under the settings of the testbed is above 70%.