Adaptive Channel Searching Scheme for Cooperative Spectrum Sensing in Cognitive Radio Networks

The MAC-layer sensing, as a key component of spectrum sensing in cognitive radio, concerns the sensing mechanism design to determine when to sense and access which channel. An important issue of MAC-layer sensing is to find an available channel with a minimized searching delay for the cognitive transmission without any harmful interference. In this paper, we focus on this issue and propose adaptive searching scheme and cluster-based searching scheme to reduce the searching time when channel conditions are various and the cooperative sensing is applied. Moreover, the optimization of these two schemes are also developed in this paper. By adaptive selecting the searching parameters according to the current environment, the average consumed time of channel searching can be minimized, while the searching quality is also satisfied. The simulation results verify the confidence of proposed schemes and show a better searching performance when combining these two schemes.