Research On Novel Spectrum Sharing Strategies In Quasistatic Cognitive Radio Networks

Cognitive radio (CR) technology emerges as the times require. According to some studies sponsored by Federal Communications Commission, many frequency bands that are regulated by the traditional fixed spectrum allocation policy, are not occupied or idle in most of the time. However, rapid development of wireless communication technologies is seriously challenged by the spectrum scarcity and low spectrum utilization problem. Fortunately, CR is the promising technology to sense and interact with its surrounding radio environment, and then enables secondary user (SU) to access licensed spectrum bands. Therefore, this dynamic spectrum access technology can dramatically enhance spectrum utilization.This dissertation is a result of the following two programs, that is, New Century Excellent Talents in University (NCET) under Grant No. NCET-06-0091 and the National High-tech R&D Program of China (863 program) under Grant No.2009AA011802. On the basis of the quasistatic spectrum environment, this dissertation does some further researches and analysis in the area of CR spectrum sharing. The content is organized as follows.Chapter one introduces the background of the research topic and presents some general information of this dissertation.Chapter two gives out the definition and the function of the CR, as well as the key technologies and the current research situations at home and abroad in detail, which offers a research clue for the author. Chapter three first presents some introductions of the spectrum sharing in CR, including the definition and some general research ideas by the numbers, which provides the author a theoretical basis of this research topic. and then the author constructs a spectrum allocation model based on the quasistatic spectrum environment, optimizing the whole CR network's throughput. Simulations approve the feasibility of this model and the corresponding solution algorithms.The model in chapter four is still on the basis of the quasistatic spectrum environment. Being different, it takes primary user activity and the heterogeneity of the CR networks into account, which makes itself a more feasible spectrum sharing model. Further, the performance analysis and simulation confirms this spectrum sharing strategy.Chapter five concludes the whole dissertation and points the future research area about the spectrum sharing in CR.