Research On Energy Efficiency And Security Technologies For Cooperative Spectrum Sensing

Spectrum sensing is the most important aspect of cognitive radio.Through spectrum sensing,the free spectrum can be effectively utilized without interfering with the primary users,and the utilization of spectrum resources can be improved.Moreover,in modern information warfare,spectrum sensing,as an effective means of communication reconnaissance,can obtain enemy information and win the initiative of war.Compared with individual secondary user spectrum sensing,cooperative spectrum sensing greatly improves the sensing performance by spatial diversity gain,but it faces the problem of increasing energy consumption;In addition,when applying evidence theory to cooperative spectrum sensing to solve the uncertain information fusion problem,it has the security problem caused by Spectrum Sensing Data Falsification(SSDF)attack.This thesis focuses on the energy efficiency problem and security problem of centralized cooperative spectrum sensing,addressing the energy efficiency problem from the perspective of frame structure optimization and the security problem caused by SSDF attacks from the perspective of reducing the weight of malicious users.The main research contents of this thesis are as follows:Firstly,a centralized cooperative spectrum sensing model is established to analyze the spectral efficiency and energy efficiency issues of cooperative spectrum sensing,and the impact of different types of SSDF attacks on the sensing performance is analyzed based on the introduction of evidence-based theory of cooperative spectrum sensing.Secondly,the model of the classical frame structure,the spectral efficiency expressions and the energy efficiency expressions are established.An optimized frame structure is proposed to make full use of the free time slots in the classical frame structure,and the heterogeneous cooperative spectrum-aware global detection probability and global false alarm probability expressions are established and applied to the spectral efficiency expressions and energy efficiency expressions of the optimized frame structure.The simulation results show that the optimized frame structure can effectively improve the energy efficiency,and the theoretical derivation and simulation analysis prove that there are optimal values for the classical frame structure and the optimized frame structure to achieve the best spectral efficiency and energy efficiency.Finally,based on the existing research on the evidence theory-based cooperative spectrum sensing method for anti-SSDF attacks,in order to further reduce the weight of malicious users in the fusion judgment,the composite entropy measure is proposed,and the composite entropy is obtained by entropy processing of the secondary user distance vector,which is transformed into the final weight to correct the secondary user perception information,and the classical fusion formula is replaced by the weighted summation method in the fusion judgment.Through simulation analysis,it is proved that the proposed cooperative spectrum sensing method based on compound entropy against SSDF attacks has better sensing performance when malicious users launch different types of SSDF attacks compared with the existing traditional algorithms at home and abroad.