Performance Evaluation for QoS in Cognitive Radio

Recent advances in communication technologies and the proliferation of wireless computing and communication devices make the radio spectrum overcrowded. However, experiments from the Federal Communication Commission (FCC) reveals that the spectrum utilization varies from 15% to 85%. Consequently, Cognitive Radio Networks (CRNs) are proposed to utilize the radio spectrum opportunistically. Most of recent researches about cognitive radio spectrum allocation based on users¿ demands are channel allocation which may not effectively use spectrum holes and meanwhile, users¿ satisfactions are not fully matched. To satisfy users¿ demand better, Quality of Service (QoS), is used to measure the Secondary Users (SU¿s) satisfaction in CRN which numerically results describes users¿ satisfaction. In this thesis, the author aims to evaluate and enhance the QoS for secondary user in cognitive radio networks through two axes namely, Dynamic Spectrum Access Schemes (DSAS) and Channel Allocation Schemes (CAS). This thesis showed through the results that the proposed spectrum access schemes and channel allocation schemes significantly improve the multimedia QoS performance for the high-priority SUs.