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.
