Research On Secure And Efficient Opportunistic Transmission Strategy In Cognitive Radio Networks

With the development of wireless communication technology,the fixed allocation of spectrum resources has been unable to meet people's needs.Cognitive radio technology can effectively solve the problem of insufficient spectrum resources,but it also brings challenges to traditional data transmission strategies,especially in resource-constrained environment where malicious nodes exist.This paper focuses on the problems of transmission strategies in cognitive wireless networks.The main work is as follows:(1)In multi-channel cognitive wireless networks,broadcasting is the most basic way to transmit data from the source node to all other nodes,and retransmitting directly affects the broadcasting performance.However,the existing work fails to make full use of the social attributes of broadcasting nodes and the broadcasting characteristics of wireless links,which will lead to greater transmission redundancy and broadcasting performance degradation.To solve this problem,this paper proposes a network coding broadcast scheme based on social attributes.The theoretical and simulation results show that the proposed scheme has better performance in the number of retransmissions.(2)In view of the resource-constrained and malicious cognitive wireless network environment,a secure opportunistic data transmission strategy for differentiating traffic flows is proposed,including a trust value calculation model for differentiated services.Secondly,the scheme adopts the candidate forwarding model based on auction mechanism,introduces the concept of resource price and service price,and gives the proof of the optimal bidding strategy and economic attribute.Thirdly,in order to ensure the quality of service of key nodes,a duplicate candidate node selection algorithm is proposed based on the difference between the priority of traffic flow and the revenue of bidding nodes.Fourthly,in order to guarantee the QoS of low priority traffic in node cache,this scheme proposes a dynamic flow priority allocation strategy based on waiting time and demand time.The simulation results show that the proposed secure opportunistic data transmission strategy has better performance compared with the existing work.