Throughput performance analysis of optimal random access policies for cognitive radio networks

Abstract

As the demand of wireless communication services increase, the utilization of radio spectrum resources becomes more important. However, most of the radio spectrums have been already allocated to licensed users, and recent studies reveal that they are not occupied for most of the time. To improve the eciency of the radio spectrum usage, the concept of Cognitive Radio (CR) has been introduced. In this thesis, we consider a time slotted CR network with N wireless channels and M SUs. After all SUs sense the state of each wireless channel, each SU selects at most L idle channels to transmit packets. We call the CR network the L-interface CR network. In the analysis we obtain the throughput of the L-interface CR network. We then use it to derive the optimal access probabilities (APs) that maximize thenthroughput performance of an arbitrary SU. We also investigate the impact of the number of interfaces L on the maximum throughput performance of an arbitrary SU.