| Aerospace TT&C technology is widely used in military,but the TT&C link is susceptible to various electromagnetic signals,especially the signals sent by human beings.The security of measurement and control link plays a decisive role in the security and accuracy of strategic information transmission.In order to ensure the communication security of measurement and control link,it is necessary to detect and identify the interference signals,and take effective measures to protect specific types of interference.Therefore,in order to cope with the complex interference environment in the space TT&C link,the interference detection and identification technology is mainly studied.The main work of this paper is as follows:1.Three interference detection algorithms based on frequency domain(CME,FCME,double threshold FCME)are studied,theoretical analysis and simulation are carried out,and the relationship between false alarm probability and interference detection decision threshold is deduced in detail.Finally,through simulation and comparison,a FCME detection algorithm which can effectively detect six kinds of interference signals and is easy to implement is selected as the interference detection scheme in the cognitive process.2.Based on the study of six kinds of interference signals in Chapter II,the characteristic parameters of each type of signal are analyzed according to the characteristics of the signal.A group of characteristic parameters that are insensitive to interference signal parameters and have a high degree of differentiation are selected,and the parameters of each signal are simulated and drawn out to analyze the decision-making process.A decision tree strategy for interference signals in space TT&C link is developed.In addition,a lightweight network model based on compressed sensing parameters of extracted signals is proposed.Firstly,the process of compressed sensing is introduced,and then the function and parameters of each module of the network model are emphatically explained.In order to compare the recognition effect,three other benchmark network models,including residual network ResNet50,ShuffleNetV2 and MobileNetV2,are introduced as comparative experiments.3.Simulate the environment of space TT&C link,build a signal sending and receiving platform,collect data in practice,and build databases under different dry signal ratios.The collected data is used to verify the proposed interference detection and identification scheme.It is proved that the detection probability of interference signal is greater than 96%when the dry signal ratio is 10 d B,which is in line with the experimental expectation. |
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