Abstract: The vehicle Ad Hoc network is a new type of intelligent network.By intelligently accessing the networkit realizes the interconnection communication between people and vehiclesvehicles and vehiclesvehicles and infrastructure of roadsideenhances the safety prediction and alarm during the driving process of the vehiclesatisfies users' needs of vehicle multimedia accessand thus improves vehicle users' experience.Aiming at the problem of low efficiency of spectrum allocation in cognitive vehicular Ad Hoc networks(CR-VANET)a spectrum allocation scheme based on improved crow algorithm is proposed.Firstlythe two updated position parameters of the crow algorithm are improved by referencing curve adaptive parameters to better balance intensification and diversification.Secondlythe convergence factor strategy is adopted to solve the problem of slow convergence and instability of the crow algorithm.Thirdlythe chaotic map is used for random numbers to improve the ergodicity and convergence speed of the search.Finallythe throughput of the vehicle network and the access fairness between the users of cognitive vehicle are used as the reference evaluation indexthe improved crow algorithm is applied to the spectrum allocation of the cognitive vehicle network.The improved schemeis seperately compared with genetic algorithm(GA) and particle swarm optimization algorithm(PSO) allocation scheme.Simulation results show that the improved allocation scheme has a better performance.

Key words: Adaptive curve, Binary crow algorithm, Chaotic map, Convergence factor, CR-VANET, Spectrum allocation