DESIGN OF A VIRTUAL WIRELESS LINK SELECTION ALGORITHM FOR RELIABILITY OF COOPERATIVE COGNITIVE RADIO NETWORKS

Abstract

Owing to the rapidly increasing number of users in the wireless technology and the renovation of voice-only communications to multimedia applications, increasing efficiency of spectrum usage is an urgent and reliable solution. Cognitive radio is considered as a promising candidate to be employed in such systems as they are aware of their operating environments and can be trained to dynamically and autonomously adjust its radio operating parameters accordingly. The objective of this research is to design, analyze and simulate a more reliable cooperative cognitive radio network that is able to establish a virtual wireless link before the actual communication starts. A system model for the cognitive radio network is developed and a virtual wireless link selection (VWLS) algorithm for cooperative cognitive radio networks is then developed. The virtual wireless link is used to carry out the end-to-end data transmission. The VWLS algorithm is then analyzed and computer simulated to show the impact of the virtual link on the performance of the network. To interpret the simulation results and explicate the relation between the number of available free channels and number of virtual links to be established, the idea of probability theory is used. Performance evaluation shows significant improvements not only in the secondary users blocking and forced termination probabilities but also in the throughput of cognitive users. By demonstrating the performance improvement of the cognitive radio network (CRN) with the help of the newly developed algorithm, it is proved that the reliability is also enhanced.