Research On Spectrum Resource Allocation In Cognitive Radio Network

With the development and the wide application of the wireless communication technologies, the phenomena is more and more apparent that a part of spectrum are overcrowded while others are idle on many occasions. By opportunistic accessing the idle spectrum, cognitive radio improves the utilization of the spectrum. Special spectrum allocation algorithms are essential to adapt the dynamic characteristics of the spectrum in cognitive radio.This thesis firstly introduces the background, basic concept and the development of cognitive radio. And then, the classification, design principle and the models of spectrum allocation are summarized. The spectrum allocation algorithms based on Graph-Coloring theory are fully studied, and their advantages and disadvantages are summarized. Based on that, this thesis presents the improved greedy algorithm and the improved fair algorithm. At last, this thesis introduces a new spectrum allocation algorithm taking user requirements and discontinuous spectrum allocation into consideration based on the Graph-Coloring theory. Simulation results show that the satisfying performance can be obtained by using the proposed algorithm. By comparing with the exhaustive search method we can see that the performance of the proposed algorithms id equal to the performance of the exhaustive search method when there is much more available resource than the users demands.