| dc.description.abstract | The development of Cognitive Radio results from the poor utilization of spectrum in wireless network. In recent years, more and more people have been doing research on the technology of Dynamic Spectrum Access to upgrade the utilization of spectrum. And Cognitive Radio, which has been received much attention, is one of such technology.
Researchers have been proposed several approaches to improve the spectrum utilization in the field of Cognitive Radio, like improving the performance of collision probability, false alarm rate, throughput, and so on. However, there is an additional device ( eg. fusion center or common control channel ) to manage CR users in most of these researches. The device, like a base station, can adjust CR network parameters by fusing the message which CR users are sensing. Moreover, this device enables CR users to access the channels in some researches. CR users, access of channels controlled by base station can make spectrum efficient, but the overhead, like PU’s interference, caused by this device, is seldom considered in such researches. In this thesis, we propose a systematic method for channel selection without any basic infrastructure.
In this thesis, cognitive radio users will gain the right of channel use by the channel selection and competition, which promises the opportunity to find the receiver in limited time and analyzes the performance of the mechanism. The proposed spectrum hopping scheme can achieve degree n for the rendezvous of secondary users. Moreover, the proposed method would make decision for secondary users when meeting the primary users in the continuing transmission strategy. In addition, we propose continuing strategy for CR user who is channel owner. The simulation results show that the proposed method has better transmission performance compared to that of the random selection scheme.
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