The Research And Implementation Of Cognitive Radio Spectrum Sensing Real-time Spectrum Based On FPGA

Cognitive radio technology provides a way to solve the tension of spectrum resources.Its core content is spectrum sensing technology.The technology find the frequency domain hole by sensing the spectrum around the band to use,to assign a reasonable frequency band to the user who needs communication.Real-time spectrum analysis is often used to detect,capture,and analyze various burst signals.In this thesis,the energy detection algorithm is used to study and implement the real-time spectrum analysis based on spectrum sensing in the broadband range of 0MHz to 1250 MHz.The thesis can be divided into the following three parts:Firstly,the classification of spectrum sensing is introduced,and the advantages and disadvantages of each algorithm are analyzed.At the same time,the algorithm of energy detection based on noise estimation is studied and simulated,by combining the spectrum sensing requirements of 0MHz to 1250 MHz wideband intra-signal blind detection.Secondly,the bandwidth estimation,carrier frequency estimation and symbol rate estimation in parameter estimation are studied in detail.In this thesis,the bandwidth estimation based on Welch transform is studied;the frequency center estimation method is studied by frequency center method,M subquery method and symbol rate estimation;the instantaneous amplitude spectrum method,wavelet analysis method and M-th square spectrum method are studied.The simulation and analysis of all the above methods are carried out.By comparing the performance and implementation difficulty of each method,the M-th method is selected by the direct method,the carrier frequency estimation and the symbol rate estimation in the hardware implementation.Finally,this thesis achieves high-speed sampling up to 5GHz.According to the requirement of hardware implementation,the method of multi-phase filter group is selected to complete the FPGA-based energy detection spectrum sensing algorithm.Completed the perception of the signal storage and into the computer,and make real-time spectrum analysis.Completed VIVADO platform and modelsim simulation to verify the correctness of each module function.And in the evaluation board XILINX-VC707 to complete the realization of the spectrum of perception,to perceive and draw different signals' real-time spectrum.