Research On Key Technology Of Spectrum Sensing In Cognitive Radio Network

The development of wireless communication and fixed spectrum allocation result in shortageof spectrum resource. However, the licensed spectrum utilization is very low. Technology ofcognitive radio achieves secondary use of spectrum by accessing licensed spectrum that is notoccupied dynamically. Cognitive radio improves the wireless spectrum utilization greatly.Spectrum sensing, a key technique of cognitive radio, is used to find available spectrum quicklyand accurately. Cooperative spectrum sensing and compressed wideband spectrum sensing arekey points of spectrum sensing. Researches on cooperative spectrum sensing and compressedwideband spectrum sensing are done in this thesis.Firstly, thesis introduces background of cognitive radio. Besides, single user spectrum sensing,cooperative spectrum sensing and compressed wideband spectrum sensing are also discussed indetail.Secondly, thesis sums and analyzes data fusion schemes of centralized cooperative spectrumsensing. In order to combine data fusion schemes together, thesis proposes an improved algorithmbased on traditional two stage cooperative spectrum sensing. Simulation results that the proposedalgorithm decreases the number of sensing bits to fusion center greatly at cost of a little loss indetection performance.Finally, reconstruction algorithm of compressed wideband spectrum sensing is studied. Thesisintroduces the common reconstruction algorithms simply and analyzes the performance oforthogonal matching pursuit algorithm. In order to improve the speed and accuracy ofreconstruction, thesis proposes a compressed spectrum reconstruction algorithm based ondetection in Underlay network. Simulation results that the proposed algorithm reduces the time ofreconstruction effectively and improves the accuracy of reconstruction by resisting the effect ofnoise.