Dynamic Spectrum Allocation Strategy With Dual Sensing Threshold In CRN And Its Performance Study

Under the background of spectrum resource shortage,the contradiction between the low utilization rate of authorized spectrum and the fast growth of non-authorized users is becoming more and more prominent.Cognitive Radio Network has become a research hot spot as a new technology to solve the contradiction effectively.This paper takes into account the service quality of primary users and secondary users in Cognitive Radio Network,considers the imperfect sensing,and studies the dynamic spectrum allocation strategy and performance based on the dual sensing threshold.Firstly,in order to improve the flexibility of spectrum allocation and ensure the quality of service for primary users,spectrum pools are set for random preemption and cooperative preemption respectively,different sensing thresholds are set for primary users and secondary users.A dynamic spectrum allocation strategy is proposed which combines dual spectrum pool and dual sensing threshold.In view of false alarms and missing errors that may occur in the perception process,a multiple servers preemption priority queue with interrupt able services is established.Secondly,on the basis of integrating a dual spectrum pool of random preemption and cooperative preemption,in order to improve the effective throughput of secondary users,the standby spectrum pool is deployed to the interrupted secondary users,and a dynamic spectrum allocation strategy combining the standby spectrum pool and the dual sensing threshold is proposed.Combining with the imperfect sensing results,a multiple servers preemption priority queue with low speed reserved services and interrupt able services is established.Thirdly,the equilibrium equation is established to solve the steady-state distribution of the established queuing model,and the expressions of the effective throughput and other performance indexes of primary and secondary users are derived.Based on the analytic results of the multiple servers preemption priority queue with interrupt able services and the multiple servers preemption priority queue with low-speed reserved service and interrupt able service,numerical experiments are carried out to reveal the trend of effective throughput of primary and secondary users,and to evaluate the effectiveness of spectrum allocation strategy.Based on the working mechanism of the proposed spectrum allocation strategy,simulation experiments are carried out to verify the rationality of the queue and the queue analysis.Finally,according to the proposed spectrum allocation strategy,individual income functions of secondary users and social income functions of the system are constructed respectively,and Sparrow Search Algorithm is improved by applying the optimal point set initialization population method to study the equilibrium arrival rate of secondary users and the optimal arrival rate of society.In order to maximize the social benefits of the system,a reasonable price scheme is formulated for the secondary users accessing the system.