Research On Channel Selection Strategies Of Cognitive Radio Networks

As an intelligent wireless communication technology which can improve the spectral utilization, cognitive radio has attracted widespread concern. It can sense wireless communication environment, adjust system parameters adaptively and have an access to free spectrum dynamically so that it solves the problem of shortage of wireless spectrum resources. Dynamic spectrum access is one of key technologies in cognitive radio which decides who access to which channel at what time. In this paper, channel selection strategy in dynamic spectrum access has been studied in order to design an efficient channel selection strategy improving the spectrum utilization of wireless communication system.First of all, this paper introduces the study background. And it also introduces the concepts, key technologies and research status.Secondly, the importance of the research of channel selection strategy is described. In addition, present channel selection strategies are compared and their shortcomings are pointed out.Afterwards, a channel selection strategy of single secondary user based on predicting idle probability is proposed, which improves the higher collision rate of traditional channel selection strategy. And simulation results show that this strategy can effectively reduce the collision rate between primary user and secondary user and improve system performance.Finally, the multi-user channel selection strategy based on water filling method is proposed, which predicts the idle time of channel, and then applies the water filling method to channel selection. This strategy improves the system throughput and spectral utilization in the way that SU transmitting more data select the idler channel.