Research On Spectrum Allocation Of Wireless Mesh Networks Based On Cognitive Radio

Wireless mesh networks as a new wireless network technology, with its low-cost, high bandwidth, etc. to attract wide attention. But with the growing number of users, the wireless mesh network is facing problem of shortage of spectrum resources. Subject to the current spectrum allocation and management, some of the bands on the spectrum usage are too high, and some band almost no use of even low usage. Therefore, in order to improve the precious resource utilization of scarce radio spectrum, cognitive radio technology will be applied to wireless mesh networks as the shortage of spectrum resources the best solution.This thesis analyzes the wireless mesh networks and cognitive radio technology features, based on in-depth study of the technical challenges of the cognitive radio spectrum allocation algorithm, and then presents network architecture hierarchy for WMN based on cognitive radio technology. In order to maximize the amount of the target access system and ensure the fairness of the cognitive users access network, by giving priority to cognitive users with relatively scarce available resources or those areas in which competition is more intense, to avoid this class of cognitive users are starving to death, it was proposed based on vertex coloring algorithm to maximize the amount of system access. As the differential evolution algorithm code is simple, fast speed, to minimize network interference as the goal, presents a spectrum allocation algorithm based on differential evolution, so that more cognitive users access the network, especially those whose available channel is more shortage, thereby increasing the amount of access to the network. Further, for the problem allocation of Solitary Island occurred during the distribution, considering the minimum of interference and the number of vertices which can not access system, we design a multi-objective algorithm for spectrum allocation based on differential evolution algorithm, which effectively solve the problem allocation of Solitary Island, so that all allocated channels between the cognitive users can communicate with each other.Based on Matlab simulation platform, the simulation experiments and performance analysis are programmed for the proposed algorithm, a series of simulation experiments verify the algorithm’s effectiveness.