Researches On Spectrum Sharing Technology Based On Cognitive Radio

In recent years, with the rapid development of wireless communication technology and the rapid growth of wireless communication business, the limited radio spectrum resources are very scarce. Cognitive radio technology can effectively alleviate the situation and become a key technology in the field of wireless mobile communication. Cognitive users dynamically share the spectrum with primary users by opportunistically accessing the idle spectrum, thus improving the spectrum utilization.Spectrum sharing technology research has been one of hotspots in the field of wireless communication. Because cognitive radio network usually configured in openly wide area, and the network equipment are different, so many spectrum sharing model is put forward to adapt to the different scenarios. In this thesis, in view of the frequency hopping communication environment, namely, primary users utilizes frequency hopping communication style in cognitive radio environment, a deep research is made based on cognitive radio spectrum sharing technology. Mainly from two aspects to study the spectrum sharing technologies: one is the study of the application of spectrum sharing environment, including the frequency hopping signal parameter estimation and frequency spectrum utilization estimation; the other one is the analysis of the similarity between markov repairable system and the spectrum sharing problem from the reliability theory, the spectrum sharing model is studied based on the reliable theory and implementation scheme.As the foundation and basis for studying the spectrum sharing problem under the environment of frequency hopping communication, an actual frequency hopping signal parameters estimation method that can adapt to the complex interference environment is studied. The method considering the actual frequency hopping signal is affected by noise and interference, through the STFT analysis of frequency hopping signal processing, improved the accuracy of parameter estimation and dramatically shorten the processing time of parameter estimation. In frequency hopping signal spectrum utilization estimation, we found that the arrival process of frequency hopping signal in each channel is a poisson process, it provides a basis to the research of spectrum sharing scheme.In this thesis, after compared the markov repairable system with the spectrum sharing problem, we set up the spectrum sharing model of frequency hopping communication environment, and expound the spectrum sharing algorithm in detail. The algorithm is based on the spectrum analysis under cognitive radio network environment, started from avoiding cause interference to primary users, matched the spectrum holes and the network access request through the instantaneous availability of spectrum and the average arriving times of primary users, thus reduced the instantaneous switching probability of system and improved the spectrum efficiency of the system. In the simulation, we compared the algorithm with random spectrum allocation algorithm, the proposed spectrum sharing algorithm can effectively reduce the instantaneous switching probability of system, and high spectrum efficiency can be obtained.