Spectrum Allocating Algorithm Of Cognitive Radio And Platform Simulation

In recent years, with the continuous development of wireless communication technology, the demand for faster and more efficient communication technology is increasing. The limited radio spectrum resources is becoming a bottleneck restricting the development of wireless technology, while the imbalance of the spectrum use has become heavy. At certain times some of the spectrum resources are crowded, while in some other time, these spectrum resources would be idle, which caused a great spectrum resources wasted. To this end, the cognitive radio technology is occurred which can intelligently choose to use the idle spectrum resources. So it is possible to make full use of these wasted resources and increase the spectrum utilization.As the key part of cognitive radio technology, spectrum allocation technology has been subjected to the full attention and has been rapidly developed around various research institutes at home and abroad in recent years. Many solution for allocating spectrums have been proposed like graph coloring model, the interference temperature model, game theory models, the auction model, and so on.In this thesis, graph col6ring model and its related spectrum allocation algorithm are studied. First, the development of cognitive radio is introduced. Then we describe some basic concepts of cognitive radio technology and introduce several typical spectrum allocation models. Next, we focus on the basic concepts and mathematical description of graph theory, and further describe some typical algorithms based on graph theory model. Then according to the color sensitive graph coloring algorithm and parallel algorithm, we develop an improved parallel algorithm by updating the topology diagram through the sub-graph coloring and introducing the color degree as the weights for spectrum allocation. Compared to the parallel algorithm the improved parallel algorithm increase the fairness of the system at the cost of consuming the allocation time. Finally, the NS2underlying modules are expanded and the power control and channel allocation module are added, which make it support multi-interface and multi-channel simulation, and has dynamic spectrum assigned function. The improved algorithm is simulated in this platform and the simulation results show that the indicators of the system are improved accordingly.