Resource Allocation Based On Cognitive OFDMA System

With the rapid development of society a nd science and technology,the application of wireless communication technology has been more and more common,increasing number of wireless users,are also constantly improve the requirement for the quality of communication,this led to the people to the unlimited resources of the contradiction between the demand and the current resources situation increasingly prominent,the development of communication industry have also been restricted,in reaction to the phenomenon,cognitive radio technology arises at the historic moment.Cognitive radio technology can effectively alleviate the problem of low frequency spectrum resource utilization,orthogonal frequency division multiple access(OFDMA)as a way of multiple access wireless physical layer,high spectrum efficiency,strong resistance to decay,high rate,the advantages of flexible allocation of resources and support more users at the same time,which makes it become the key core technology of next generation wireless communication.Therefore,how to reasonably implement OFDMA resource allocation to improve CR system performance has become an important research topic.The research on the resource allocation algorithm based on cognitive OFDMA system has been mature,and the research is carried out on the basis of these models.At present,some scholars have proposed the resource allocation technology based on the transmission power minimization model,and the resource allocation technology based on the total capacity maximization model is proposed.But these models are unilateral minimize power consumption or simply to reach highest capacity,without considering the unity of the organic combination of both,effectively improve the energy efficiency.Spectrum resource excessive consumption of the existing problems,the author of this paper,based on the orthogonal frequency division multiple access,cognitive radio network the uplink bandwidth and power is the product of the utility function is put forward to model,in this model,the cognitive user interference with primary user USES the probability of interference constraints under imperfect channel state information,and the total power of the cognitive users is limited.The model to minimize the power of the traditional model and capacity maximization model organic unifies in together,in the improved model can guarantee the cognitive users and the normal communication main users save spectrum,the use of the cuckoo search algorithm is obtained by iterative solution of the problem.The simulation results show that compared with the traditional model,this paper improves the efficiency of the spectrum and saves the resources greatly.