Spectral Allocation Based On Distribution Regulation Factor And User Requirement

Dynamic spectrum allocation is one of key cognitive radio technologies. Thepaper mainly researches two aspects of spectrum allocation. On one hand, acquiresystem throughput as much as possible. On the other hand, allocate spectrum fairly.Specifying the transmission rate as the indicator of system throughput, the paperproposes an improved parallel algorithm of Color-Sensitive-Graph-Coloring (CSGC)principle based on allocation adjustment factor for centralized cognitive radiocommunication network. By using the allocation adjustment factor, the cognitive userhas the higher predicted system total transmission rate the lower access priority andthe more amount of allocated spectrum bands the lower access priority. Therefore, thespectrum allocation can better balance the total transmission rate of the system andthe allocation fairness of the cognitive users, meanwhile, the time overhead keeps lowbecause of using parallel allocation method.However, the proposed algorithm do not take each cognitive user’s minimumtransmission rate needs to safeguard the communication quality into consideration. Itmay lead to the low-demand cognitive users acquire much transmission rate, but thehigh-demand cognitive users acquire so little transmission rate that cannot ensurecommunication quality. It leads to unreasonable use of wireless spectrum resources.On the basis of the proposed algorithm, combined with the minimumtransmission rate requirements to safeguard communication quality, the paperproposes the dynamic spectrum allocation method based on a new Access-Screeningmechanism. The introduced Access-Screening mechanism compares the sum ofacquired and acquisitive transmission rate with each cognitive user’s minimumtransmission rate requirements in the interference topology graph, the user whose sumvalue less than the requirement quit allocation. The numerical simulation results showthat the allocation method with Access-Screening mechanism can balance the systemtotal transmission rate and the allocation fairness and meet more cognitive users’ demand. It can safeguard more cognitive users’ communication quality and reduce thewaste of spectrum resources.