Multi-Channel Based Dynamic Spectrum Allocation Strategy And Performance Study In Cognitive Radio Network

In order to improve the spectrum utilization,cognitive radio networks can save the problem by using the spectrum secondary.To cognitive radio networks,based on muliti-channels,we analysis the performance of system,and optimize the system.At first,In order to improve the spectrum utilization,conbining the merits for both the overlay mode and underlay mode,we propose a novel hybrid dynamic spectrum allocation strategy under multi-channel.Considering the channel switching,based on service radio swicthing,we bulid a multi-service queuing mode.Considering the impect of imperfect sensing on the system performance,based on the alterm error and flase error,we propose a dynamic spectrum allocation strategy under imperfect sensing.In order to ensure the benefit of pority users,at most one secondary user is allowed to use the channel opportunitily.Based on the propoed strategy,we bulid a multi-service preemptive priority queueing mode under imperfect sensing.Secondly,based on the service radio swicthing multi-service mode,we establish a discrete-time Markov chain.Using the matrix geometric solution method mode to analysis the steady-state of system,we give some system performances expressions such as the channel utility,the averagy delay o f cognitive user packets,and the normal throughput of authorized user packets.We anysis the system performance by the result of the performance measures.Then,based on the multi-service preemptive priority queueing mode under imperfect,we establish a discrete-time Markov chain.Using the matrix geometric solution method mode to analysis the steady-state of system,we give some system performances expressions such as the channel utility,the averagy delay o f cognitive user packets,and the normal throughput of authorized user packets.We anysis the system performance by the result of the performance measures.Finally,based on the two kinds dyna mic spectrum allocation strategies,making the experiments,we find the imfect of the number of channels of a spectrum on the system,and verify the effective of the of two kinds dyna mic spectrum allocation strategies.Based on the trade-off relationship between different performances,we contruct the system benifit functions,and give the system optimal strategies.