Research And Implementation On Spectrum Sensing Technique Of Cognitive Radio System

In recent years, as the rapid development of wireless communication technology, the contradiction between the growing demands and the lim ited spectrum resources has become one of the main bottlenecks that restrict the development of wireless communication. As an intelligent wireless communication technology, cognitive radio can discovery and reasonably use the free spectrum among distributed spectrum without affect authorized users, which improves the utilization ratio of an existing spectrum. Spectrum sensing is one of the basis of cognitive radio system, which is the first problem to be solved.This paper mainly studies the key technology and a hardware implementation of spectrum sensing used in cognitive radio. Firstly, it introduced the present research status of cognitive radio and spectrum sensing at home and aboard. Then it introduced the present spectrum sensing methods in detail, and contrastive analysis them, summarized the advantages and disadvantages of each method, choose the energy detection algorithm to complete the follow-up studies according to the project needed. Energy detection with different parameters are analyzed in Matlab platform, spectrum sensing system based on energy detection has carried on the modeling and simulation. A hardware implementation diagr am of spectrum sensing based on energy detection was proposed, mainly introduced the digital baseband signal part of the FPGA implementation and validation process. Finally, by setting different parameters, I did performance simulation and analysis of the detection system and the results consistent with the theoretical analysis, which means the system can correctly detect occupation of the band.This design is programmed by hardware description language called Verilog HDL, simulated by using ISE13.3 belonged to Xilinx company and Modelsim belonged to Mentor Graphics, which is built on virtex-6 Pro FPGA of the Xilinx Corp. This study is useful to explore the research of cognitive radio, which is actively significant for the next research.