Research Of Cognitive Radio Technology Based On OFDM

With the rapid development of wireless communication technology, demand of peoplefor radio spectrum resources continue to increase, the frequency spectrum resource scarcity ismore and more obvious; spectrum resource shortage has restricted the rapid development ofwireless communication. Currently static spectrum allocation policy makes spectrumutilization rate low, CR is dynamic spectrum management, which is considered as a new wayto improve utilization rate of spectrum resource and capacity of the users and to reduce stressspectrum resource use. These articles combine OFDM technology and CR, improving thespectrum utilization.This paper firstly introduces some common concepts and key technology in cognitiveradio systems, common concepts and key technology in research of cognitive radio spectrumsensing technology based on, introduced the method of single user perception and thecooperative detection of these two types of spectrum detection, and theyare performance simulation and comparison. Each spectrum detection methods have theirown advantages and disadvantages, only according to the nature and needs of cognitiveusers to select the appropriate test methods to obtain the optimal detectionresult. Then, describes the basic working principle and resource allocation methods of OFDMtechnology, the establishment of cognitive radio system model based on OFDM, theinterference of cognitive user analysis system of the primary user and the primaryuser in cognitive users. Finally, learning classification and distribution principle of cognitiveradio spectrum resource allocation through the study, based on cognitive radio system modelbased on OFDM is established, introduces four subcarrier allocation algorithm forspectrum resource allocation scheme based on the linear water floodingmechanism and power allocation algorithm, proposes a simplified PIA algorithm and PIB PIalgorithm, a simplified algorithm low complexity but the performance close to that of theoriginal algorithm. At the end of the text summary and outlook, are summed up the researchwork done in this paper, and the deficiency in the research is analyzed, the researchwork after further development are briefly described.