Underlay Cognitive Radio Networks Based On Queuing Theory

With the expansion of wireless networks and the explosive growth of mobile devices,the traditional radio distribution scheme(static allocation)has been unable to meet the requirements of the development in the times.In some dedicated communication networks,some of the spectrum has not been fully utilized.Since 2000,the rapid development of cognitive radio technology,has made more efficient use of existing idle spectrum,solving the shortage of spectrum resources which due to the increased radio equipment.The main idea of the cognitive radio performance in cognitive users can not interfere with the authorized users while using authorized frequencies,realize the transmission of signal.the research of cognitive radio is mainly focused on the spectrum perception,spectrum allocation,and other technologies to improve the utilization of spectrum resources and system throughput.In this paper,we study the access and allocation of spectrum resources in understand cognitive radio communication mode,and use the queuing theory and polling techniques to analy-ze the basic performance of the system.Firstly,This paper introduces the background knowledge of cognitive radio,including the background and spectrum allocation of cognitive radio,the definition of cognitive radio,the main features,the architecture and the applicable scene.Then,the knowledge of queuing theory and lining CR network is expounded,and the queuing theory model is established by M/M/1 in CR network.Theoretically,the average latency of the system in the CR network is obtained,and the queuing theory is verified by the experiment.The feasibility of the queuing theory in the CR network is verified by experiments.Aiming at the characteristics of large volume of business in the CR network,there are many data service waiting services.In this paper,the same data service as a queue,in the case of multi-queue,through the establishment of three queuing models:full service CR network,the threshold service CR network and limited service CR.The average delay of the complete service CR network is obtained by the experimental simulation that average queue length is the smallest.In the wireless communication system,the average delay and average queuing of one of the long key indicators,in the real-time requirements of the business is suitable for full service access and distribution.In the multi-queue,in the case of heterogeneous data on the CR network often have to consider the priority,such as the system control signal,often have a higher priority.In this paper,we use two levels of service to meet the needs of high priority queues.On this basis,we propose a two-level mixed poll service model,which satisfies the characteristics of high priority queue and take into account the fairness of services in ordinary queues.The feasibility of the scheme is proved by experimental simulation.