Key Technologies Research And Implementation Of Low Interception Communicaton In Complex Electromagnetic Environment

With the advent of the information age,Electronic Countermeasures(ECM)is the main symbol of the informationization battlefield and is active on the stage of modern warfare.Various military and civilian electronic devices have made the electromagnetic environment in modern battlefield space very harsh,posing serious challenges to communications.In a complex electromagnetic environment,how to carry out safe and reliable communication transmission and prevent information from being intercepted and detected by the enemy is the key to the success of electronic warfare.Therefore,this paper focuses on the Low Probability of Interception(LPI)communication transmission waveform in complex electromagnetic environment:First,it introduces the relevant knowledge of spread spectrum communication system,including its theoretical basis and performance indicators,various pseudorandom noise(PN),direct sequence spread spectrum system,frequency hopping communication system,multi-frequency spread spectrum The basic principles of the system.Then the low intercept probability communication system is summarized,the scene model of the communication system is given,and the low intercept probability is analyzed,and corresponding measures are given.Second,combined with the actual application scenario,the overall design of the system is given,and the design of the frame structure and the signal processing flow of the entire link are described.Aiming at the weak points that the transmission waveform is easy to be detected due to the fixed parameters in the traditional communication signal,this paper designs a non-stationary signal waveform which can effectively reduce the intercept probability by introducing time-varying communication parameters,and gives the achievable construction scheme and Related parameter design.At the same time,the multi-ary spread spectrum system with excellent anti-interception performance is discussed,and the design scheme of key technologies is proposed.Finally,MATLAB simulation analysis is performed on the whole link of the system.Thirdly,on the system hardware platform,the principle analysis of the key technologies of the entire link transmission and reception is completed,and the system implementation based on Field Programmable Gate Array(FPGA)is completed,which mainly includes: Cyclic Redundancy Check(CRC),channel coding and decoding,interleaving and de-interleaving,multi-ary spreading and despreading,scrambling and descrambling,framing,shaping filtering,digital frequency conversion and other modules.At the same time,complete the configuration of the peripheral chip interface such as phase-locked loop,analog-to-digital conversion,digital-to-analog conversion and the debugging of the hardware platform to ensure that the chips can work normally.Finally,build the actual test platform of the system,perform functional verification and system communication performance testing,and analyze the test results.The test results show that the link function of the whole system is implemented correctly,and the actual error performance is close to the MATLAB simulation result,which meets the requirements of the system.