| This thesis comes from the National High-Technology Research and Development Program ("863"Program):The evaluation and testing of Dynamic Spectrum Sharing technology. With the rapid development of wireless communications, the number of wireless devices and services has been increased greatly in recent years, which leads to the growing demand for spectrum resources.However, the issue that spectrum resources scarcity is becoming increasingly prominent. Cognitive Radio (CR) which was proposed lately has brought an opportunity to address this contradiction. It's fundamental target is to maximize the efficiency of the spectrum usage, and it is widely regarded as an effective way and a major direction of future wideband wireless communication to resolve the spectrum scarcity problem.However, it is obviously not feasible to carry out CR services in all bands indiscriminately. Detailed spectrum measurement and evaluation on each band must be done in advance in order to have a clear understanding of spectrum occupancy and characteristic parameters.The result of measurement data analysis can provide realistic basis and technical support for the competent authorities to work out spectrum allocation policy and CR management formulation.There should be simple, practical and efficient methods for the spectrum measurement. In this thesis, specific measurement solutions and spectrum data processing method were developed, based on the Beijing spectrum occupancy measurement tasks.These works constitute the spectrum measurement specifications.Additionally, a SUIEA_CR algorithm was designed to estimate the spectrum utilization increment by CR.Furthermore, according to the actual measurement data and the channel model theory, mathematical models of how the Licensed Users occupy channels were built for the UHF band and GSM band respectively. On this basis, an interface sub-layer model which can provide reference model and support data for the link-level and system-level simulation of CR was designed. |
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