Queuing-Theoretical Multi-user Spectrum Sensing and Access in Multi-channel Cognitive Radio Networks

The rapid growth of wireless communications has made the spectrum resource becoming more and more scarcity. The concept of cognitive radio was proposed to address the issue of spectrum efficiency and had been receiving an increasing attention in recent years. In the cognitive networks, the secondary users (SUs) are allowed to sense, detect and access the frequency bands that are not currently being in use by primary users (PUs). SUs must equip with the spectrum sensing and access technology to utilize the spectrum resource and guarantee PUs´ communication quality of service. Most former works study spectrum sensing or spectrum access respectively. And, when there are multiple SUs and multiple channels, the spectrum detection and spectrum sharing must be considered. In this paper, we propose a framework of multi-user spectrum sensing and multichannel spectrum access mechanism for the SUs confronting with unknown primary behavior. We also study the interference to PUs caused by the dynamic access and the inaccurate spectrum sensing. We analysis the interference caused by SUs through utilizing renewal process theory and derive the corresponding closed-form expressions. Under the constraints of the interference to PUs and the secondary network´s stability, the queuing theory is utilized to obtain the maximum ave.rage data rate of SUs under the inaccurate spectrum sensing. Through lots of simulations, we verify the effectiveness of our analysis.