Research On Multi-factor Decision Of Accessing In Cognitive Radio Networks

Cognitive Radio(CR), can sense its environment so as to access the white spectrum, it provides an effective way to solve the shortage of spectrum resources. As the cores of cognitive radio network, spectrum sensing and spectrum allocation are two important processes to make secondary users access network. Existing researches are respectively on the two processes, nevertheless, the results of spectrum sensing affect the spectrum allocation, and the spectrum allocation has a positive effect on the behavior of secondary users, they interact with each other and cannot be separated. Recent studies lead to lack of cognitive radio wireless network performance, so studying relationship between the two aspects and calculating the probability of obtaining spectrum are important to secondary users accessing networks. Moreover, energy consumption has been an important challenge in cognitive radio networks. In the case of electricity sufficient, to ensure the accuracy of spectrum sensing data and on-demand obtain resources are the ultimate goal of secondary users How to obtain the corresponding service with the smaller power consumption and reduce the unnecessary energy consumption gradually becomes a hot topic. Considering relationship between spectrum sensing and spectrum allocation and the power surplus, this thesis studies the decision whether access to the cognitive radio networks, specific works are as follows :This thesis proposes a decision-making method in cognitive radio networks based on multi-factor include the demand of secondary users, with this method, the secondary users decide whether to join cognitive radio networks considering energy surplus and the probability of obtaining a plurality of resources and other factors.(1)Pre-allocation of spectrum, the primary user's signal is stored in database, and database forecast primary user' channel state in next time through above information. Then the spectrum pre-allocation method is proposed according to the relationship between the spectrum sensing and spectrum allocation. Using this pre-allocation method, secondary users can know the probability of obtaining the applied spectrum resources.(2)Decision, secondary users take their remaining capacity, as well as the spectrum pre-allocation probability into account, and use the multi-factor decision-making method to decide whether to join cognitive radio networks. Before secondary users make the decision,the probability of accessing networks must be calculated.(3)Performance analysis, After the determination of accessing in cognitive radio networks, secondary users sense the spectrum and allocate it. According to the results of spectrum allocation, we study the secondary user's satisfaction and the overall performance in the network. Simulation and analysis show that the multi-factor decision can help secondary users with the decision whether to join the cognitive radio networks, it also can ensure secondary users' satisfaction, and can effectively improve the overall performance in cognitive radio network. Multi-factor decision lay a good foundation for the further implementation of the cognitive radio networks.