Research On Spectrum Allocation Algorthm In Cognitive Radio

In order to protect the special services against the disturbance, the inherent spectrum management mode assigns some characteristic bands for them, which causes the waste of the resources seriously. So the cognitive radio not only changes the embarrassing situation that there are not frequency channels could be used but also increases the utilization of spectrum. It is a hot topic of wireless communications, and the technology of the allocation of spectrum is one of the keys in the cognitive radio.According to the reference documentations, so far, more attentions are paid to the benefit and fairness results of the whole. However, people ignore the bottleneck users. And on the other hand, once the cognitive users'transmitting powers are lower than the main users', the SINR could be improved. So the paper is written by the two spots.This article takes the spectrum allocation algorithm as the object of study. Firstly, introduce the background, present situation and applications of cognitive radio and so on. Secondly, research the main models of the spectrum allocation algorithm, such as the interference temperature model, auction model, graph coloring model and the game theory model. Then on the base of them, the paper pays more attention to the graph coloring model, and advances to make the parallel spectrum allocation algorithm compare with the rules of CMMB and NMMB, achieving the requirement of the rule of MMB and cutting down the time of spectrum allocation. Consequently, the way improves the requirement of limited spectrums. The simulation shows that in the situation of the paper, comparing to CSGC, when the numbers of users are growing up, the method does not make the time of spectrum allocating increase as the numbers of the frequency spectrums, but keep a level, which is less than a upper bound. Moreover, on the basis of the game theory and genetic algorithm, it proposes a new algorithm—GCG, which could combine the two kinds of algorithms. GCG enhances the lower SINR. We can see from the simulations, no matter what the coefficients of price and steep change to, GCG still could enhance the SINR of the system and goals, while keep the same transmitting powers.