Reaserch And Implementation Of Cognitive Radio MAC Layer Protocol Based On SoftMAC

To solve the shortage of radio spectrum in modern society, researchers proposed a variety of new technologies. Cognitive radio technology is considered to be one of the best solutions to solve the shortage of spectrum resources which solve the problem from the point of view of spectrum allocation. The research on cognitive radio technology is increasingly further. However, cognitive radio research has focused on theoretical simulation, the corresponding hardware platforms are uncommon and expensive. So this paper is to build a cognitive radio platform using the 802.11 wireless devices in Linux system which MAC layer could be different.Firstly this paper introduces the theory of cognitive radio and its key technologies to explain the realization of cognitive radio platform. And make a brief summary to the current study of cognitive radio hardware platform.Then we analyze the base platform of the cognitive radio platform SoftMAC. SoftMAC is MAC layer research platform based on open source Linux-based wireless network card driver Madwifi. We first analyze the structure and realization of Madwifi, then described the features of SoftMAC and analyze why SoftMAC can be used to build the cognitive radio research platform.Followed we illustrate how to realize key technology of cognitive radio using SoftMAC:spectrum sensing, spectrum management and time synchronization, and take experiment to prove correctness of realization methods. Finally, using the above methods, we built a simulation platform for cognitive radio Mac layer, while on the platform we examined the function of the platform.