Improving Spectrum Efficiency by Cognitive Radio Network using Co-Operative Method

Recent studies show that the fixed spectrum assignment policy enforced today results in poor spectrum utilization. To address this problem, the concept of cognitive radio is proposed to address the issue of spectrum efficiency and has been receiving an increasing attention in recent years, since it equips wireless users the capability to optimally adapt their operating parameters according to their interactions with the surrounding radio environment. Cognitive radio is widely regarded as one of the most promising technologies for future wireless communications as it addresses the spectrum scarcity problem that is encountered in many countries. It is done by allowing unlicensed (secondary) users to coexist with the licensed (primary) users under the condition of protecting the latter from harmful interference. The cooperation performance of a primary user and a secondary user is evaluated by the switched based scheduling scheme and the throughput maximization is analyzed via simulations for both the frameworks of active, inactive Primary User (PU) and Secondary User (SU).