Research On QoE Provisioning Schemes In Cognitive Radio Networks

With the increase of mobile services, the needs and requirements of users for different services are constantly enhanced. But the development of the wireless network communication was restricted by limited frequency resources and low utilization ratio of most authorized frequency band. Cognitive radio can take full advantage of the authorized spectrum using the adaptive spectrum allocation methods to improve the existing spectrum management.How to evaluate and ensure the quality of services and network and the experience of users comprehensively while improving the utilization of spectrum in Cognitive Radio Networks (CRN) was worth studying. Therefore, this thesis was based on Quality of Experience (QoE) and QoE assessment model which was combined with key communication technologies in physical layer and network layer. Then we studied the QoE provisioning schemes in CRN through beamforming and relay scheduling.In this paper, we studied QoE provisioning schemes for a multi-user beamforming optimization model and a queuing based optimal relay scheduling problem in CRN. We designed a QoE provisioning model with a comprehensive consideration of beamforming in physical layer and the key indicator of performance assessment. Particle swarm optimization (PSO) algorithm was utilized to solve the optimization problem and the simulation results indicated that better service satisfaction and higher power efficiency were gained with the QoE provisioning model. We also designed a QoE provisioning scheme with multiple optimized goals about higher capacity and lower packet loss probability in cognitive radio relaying network. The simulation results showed that our mechanism could get a much better performance on packet loss with suboptimum system capacity, so as to improve the overall network performance and promote user experience.