| With the rapid development of wireless communication technology,the demand of people for wireless communications services is growing,the wireless transmission rate requirements is also gradually increasing,resulting in the shortage of radio spectrum resources.But the current static spectrum allocation strategy lead to the decrease of spectrum utilization.Cognitive radio technology provide an efficient way to ease the tension of spectrum,improve spectrum utilization,has been broadly concerned by scholars and research institutions.In this paper,spectrum allocation technology is studied which is a key technology of cognitive radio.Propose spectrum allocation algorithm based on evolutionary algorithms and spectrum aggregation to improve the performance of spectrum allocation and the need of cognitive users.Firstly,in order to solve discrete optimization problems in cognitive radio spectrum allocation and improve network efficiency,propose a Discrete Quantum Particle Swarm Optimization(DQPSO)algorithm.The DQPSO algorithm updates the particles with quantum computing theory and adjusts the rotation angle with wave function,and has proved its validity though to test function tests.Applied in spectrum allocation problem,experiments show that compared with the classical CSGC algorithm and evolutionary algorithms,the algorithm can improve network efficiency in different benefit functions and ensure fast convergence.Secondly,based on the spectrum aggregation algorithm does not consider the bandwidth demand degree of cognitive users,this paper proposes a cognitive radio spectrum aggregate allocation according to demand degree of cognitive users.In consideration of the transmission characteristics of users on different channels,the algorithm set demand factor for different users,representing the degree of theirs demand for spectrum resources,experiments show that the algorithm can effectively improve demand satisfaction of the cognitive users while maintaining system throughput. |
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