Research On Spectrum Sensing And Management Technology Of Electromagnetic Environment

With the rapid development of equipment informatization and networking,the electromagnetic environment in the battlefield has become increasingly complex.Radar,communications,electronic countermeasures and other electronic devices are densely distributed in the environment,and the electromagnetic countermeasure between the two sides is fierce.Introducing spectrum sensing and management technology in cognitive radios into the battlefield electromagnetic environment can greatly increase the utilization of spectrum and the operational performance of frequency equipment.Based on the application scenarios of spectrum sensing and management in the battlefield,this thesis simulates and analyzes spectrum sensing algorithms.According to the graph theory coloring model,two spectrum allocation strategies are proposed for different scenarios.As shown below,the main work of this thesis contains:1.The main radiation signal models in the battlefield electromagnetic environment is Established,including radar signal models and communication signal models.The linear frequency modulation,pulse coding,regular pulse,ASK,FSK,PSK,MSK signals are simulated and analysed.2.The spectrum sensing algorithm is studied,focusing on modeling and simulation of matched filter detection algorithm and energy detection algorithm.Firstly,the effectiveness of the above two algorithms is studied by using radar signals and communication signals.The important factors that affect the detection performance of the two algorithms are studied,and the detection performances of the two algorithms with different SNRs are compared and studied.The simulation results show that the performance of matched filter detection algorithm is obviously better than that of energy detection algorithm when SNR is low.However,when multiple signals need to be detected at the same time,the matched filter algorithm needs to detect each signal in turn,and the energy detection algorithm can be completed at one time.Then based on the application scenarios of spectrum sensing and management in the battlefield,energy detection algorithms are used for sensing analysis of multiple communication signals in the environment,and the spectrum holes in the target frequency band in space are obtained.3.Three spectrum allocation models such as Game Theory,Auction Bidding and Graph Theory Coloring are studied,and their applicable scenarios are analyzed.The graph theory coloring model takes into account the requirement of the spectrum holes for each signal and the coexistence relationship between the signals,and has better flexibility in the redistribution of signals in the electromagnetic environment of the battlefield.So,The Graph Theory Coloring Model is used to model the simulation scene,and propose two distribution ideas for whether or not there is a need to add guard bands between different types of signals.Combining this application scenario,the algorithm is deduced,and the occupancy of allocated spectrum is simulated.Finally,the redistribution of spectrum in the presence of interference is analyzed.The results show that the two allocation strategies are reasonable and flexible.