Research On Blockchain-Based Spectrum Intelligent Sensing And Sharing For Wireless Networks

With the explosive growth of mobile equipment(ME)and new services in the fifth generation(5G)wireless communication networks,the traditional static spectrum allocation and management mechanisms cannot meet the traffic needs of 5G wireless communication networks.The cooperative spectrum sensing(CSS)and dynamic spectrum sharing(DSS)technologies in the cognitive radio(CR)can solve the problem of spectrum shortage and underutilization.In general,a centralized fusion center is introduced in the CSS for the fusion of spectrum sensing data.Once the centralized fusion center suffers from a single point of failure,the whole communication system may break down.In addition,in the DSS scenario that multiple secondary users(SUs)and primary users(PUs)from different operators coexist,the private information interactions among mutual-trustless SUs and PUs may lead to privacy disclosure and security issues.Therefore,designing a new architecture for the spectrum intelligent sensing and sharing in 5G mobile communication systems is a significant challenge.First of all,considering that the centralized fusion center may suffer from trust and security issues,a CSS architecture based on the Tangle blockchain is constructed in this paper,in which massive ME act as spectrum sensing nodes and blockchain nodes.Besides,given the limited energy of massive ME and the optimization of sensing utility,an algorithm for solving the optimal dynamic spectrum sensing strategy of massive ME based on the mean field game is proposed.The simulation results show that,compared with the traditional fixed spectrum sensing strategy,the proposed dynamic spectrum sensing strategy can improve the sensing utility of massive ME when the residual energy is low,and the weighted sensing utility of massive ME is enhanced by 10.3% on average.Then,based on the dynamic change of the PU state,and the impact of perceptual data differences in different time slots on the overall decision,a new two-step spectrum sensing fusion mechanism based on the age of information(Ao I)and cumulative weight(CW)of transactions is proposed in this paper.The simulation results demonstrate that,compared with the traditional soft fusion mechanism,the detection probability of the proposed twostep spectrum sensing fusion mechanism based on the Ao I and CW is maximally increased by 30.23%,and the false alarm probability is minimally reduced by 9.92%.Finally,the blockchain is introduced into the DSS scenario where multiple SUs and PUs from different operators coexist.A multi-operator spectrum sharing(MOSS)smart contract based on the double auction and free-trading market mechanisms is designed.To verify the effectiveness of the MOSS smart contract,a private blockchain based on the Ganache is constructed.The gas consumption of each function in the MOSS smart contract is tested on the Remix integrated development environment.The analysis results demonstrate that the proposed spectrum sharing mechanism is better than the existing spectrum sharing mechanism regarding security and reliability.In this paper,the blockchain technology is introduced into the spectrum sensing and sharing,and a new architecture for the spectrum intelligent sensing and sharing that considers the credibility,sensing efficiency and accuracy is proposed.This paper provides new ideas and methods for the applications of blockchain in the field of cognitive radio.