Research And Implemention Of Cognitive Radio Plateform Based On Spectrum Sharing In Polarization Domain

With the rapid development of wireless communication technology, wireless spectrum resource shortages grows problem. Cognitive radio is considered as an effective solution to this problem. In the IEEE802.22standard, second users can accurately sense the spectrums owned by primary users, and access to the spectrums when they are idle. Currently, most of cognitive radio platforms built by researchers are similar to the opportunistic spectrum access scheme defined in the IEEE802.22standard. However, in recent years, with the study of the polarization characteristics of the wireless signal, spectrum sharing scheme in polarization domain has also become a hot topic in cognitive radio. But the current researches in this regard are at the stage of theoretical and computer simulation does not have a practical platform for theory verification.With researching on spectrum sharing scheme in polarization domain, we built a cognitive radio platform of polarization domain based on USRP and GNU radio. In the research and implementation process of the platform, the main work is as follows:First, with the study of cognitive radio and the basic theory of polarization in-depth, we designed the implementation scheme of our platform. In this scheme, the second users can opportunistically access channels and change their work mode to polarization spectrum sharing when primary users come.Then, we built the physical layer and media access control layer of the platform. In physical layer, variable polarization sender, polarization matching receiver and polarization state recognition algorithms et al are implemented. Access control, polarization state recognition control, work mode control and so on are implemented.Last, the result of functional test and performance test proved the feasibility of polarization spectrum sharing scheme in practice. Especially, the result of switching time test on operating mode switching shows our platform can improve the communication efficiency of second users. And the test result of spectrum utilization shows that our platform can effectively improve the spectrum utilization.