An Admission Control Algorithm for Multiuser OFDMA-based Cognitive Radio Networks

Cognitive radio (CR) has been proposed as a way of exploiting unused spectrum bands (also called spectrum holes). However, several experiments have indicated that the currently allocated spectrum is underutilized due the static nature of the spectrum assignment. This paper presents an algorithm that allows us to obtain admission control of secondary users (SUs) in a multiuser OFDMA-based CR network implemented in the cellular system. We also analyse the effect of primary unit (PU) and secondary base station (SBS) activities on available resource allocation. Thus, the suboptimal sub-carrier and power allocation scheme with the minimization of the total transmission power keeping the allowed interference to the PUs and SBS are obtained. The simulation results demonstrate that the joint admission control and resource allocation problems are treated in a practical way.