Research On Channel Assignment Technology In MRMC Cognitive Radio Ad Hoc Network

With the rapid development of wireless communication technology,wireless spectrum resources become more and more scarce.We need a more flexible and efficient communication mode to use the limited spectrum resources.Compared with traditional wireless ad hoc networks,cognitive radio ad hoc networks do not have fixed licensed spectrum.Cognitive users use the idle licensed spectrum opportunistically for communication by perceiving the situation that the primary users use the licensed spectrum in the surrounding wireless environment,which is considered as the key technology to improve the efficiency of spectrum utilization.Compared with single channel network,multi-radio multi-channel network can make full use of the channel resources in the network,so as to improve the network capacity.Considering the dynamic characteristics of idle channel resources,the design of channel assignment algorithm in multi-radio multi-channel cognitive radio ad hoc networks faces new challenges.In this paper,the channel allocation problem in multi-radio multi-channel cognitive radio ad hoc networks is studied,and two different channel allocation algorithms are proposed to optimize two different performance of the network.The specific research contents and corresponding results are as follows:First of all,this paper introduces the multi-radio multi-channel cognitive radio ad hoc network in detail,studies the characteristics of the network,analyzes the problems existing in the network,and obtains the key points that should be paid attention to when allocating channels in the network.Based on the analysis of the advantages and disadvantages of the existing channel allocation algorithm,the breakthrough of the design of channel allocation algorithm is found.Aiming at the requirement of delay minimization in multi-radio multi-channel cognitive radio ad hoc networks,this paper proposes a delay minimized channel assignment based on cognitive radio(CR-DMCA).In CR-DMCA,cognitive nodes use idle channel resources opportunistically without harmful interference to the primary user,try to avoid the impact of the dynamic use of licensed channel by the primary user,reduce the number of hops between nodes in the network,and make the network delay performance optimal.In this paper,CR-DMCA algorithm is realized by MATLAB simulation.From the simulation results,CR-DMCA algorithm can significantly reduce the network delay.Compared with other algorithms,CR-DMCA algorithm reduces the average network delay by 13%to 27%.For the demand of throughput maximization in multi-radio multi-channel cognitive radio ad hoc networks,this paper proposes a throughput maximized channel assignment based on cognitive radio(CR-TMCA).In CR-TMCA,cognitive nodes reduce the interference between nodes,reduce the number of hops between nodes,and improve the throughput performance of the network on the basis of not interfering with the primary user,avoiding the influence of the primary user activities as much as possible,and ensuring the connectivity of the network.In this paper,the CR-TMCA algorithm is realized by MATLAB simulation.The simulation results show that the CR-TMCA algorithm greatly increases the network throughput.Compared with other algorithms,the CR-TMCA algorithm improves the average node throughput performance by 30% to 102%.