Transmission Strategies In Cognitive Radio

In cognitive radio network, secondary users' behavior can be divided into two phases:spectrum sensing and data transmission. In common sense, the longer the time of spectrum sensing, the higher detection probability, and authorized users can be more effectively protected. On the contrary, the longer the time of data transmission, the larger secondary users'data throughput. And we can find that spectrum sensing and data throughput are a contradiction. So that it is need to find an compromise strategy which allows secondary users to adjust the frequency of the implementation of spectrum sensing operation according to the state information of authorized users, which aims to minimize the interference to authorized users and maximize the data throughput of secondary users at the same time. Therefore, the research on adaptive transmission strategies in cognitive radio network will be very valuable and meaningful.Based on the above ideas, this paper presents three transmission strategies and describes how them work in detail. And then we do computer simulation mainly from two angles-the collision probability and data throughput and the results show that:the three transmission strategies can significantly reduce the collision between secondary users and authorized users and maximize data throughput. Finally, we compare the performance of the three strategies together showing that the first transmission strategy is optimal. The thesis consists of five chapters and the main work is as the following:The first chapter makes a brief introduction to the background of this paper. The second chapter mainly shows some previous research works related to transmission strategies in cognitive radio network from the perspective of the working principle. The third chapter describes the three proposed adaptive transmission strategies in detail and introduces the system workflow used for the above strategies. Chapter IV shows the simulation results of the above three adaptive transmission strategies form the aspects of collision probability and data throughput respectively and does some comparative analysis of the three adaptive transmission strategies'performance. Finally, we do a summary of the whole work...