LPI Waveform Design Method For Intentional Utilization Of Electromagnetic Background

In the face of advanced processing technologies such as detection,sorting and identification,and parameter estimation in reconnaissance systems,low probability interception(LPI)radar can increase the difficulty of reconnaissance system analysis and processing,achieve concealment and preemption through low sidelobe antennas,resource control,waveform design,and other means,and is a research hotspot in the field of electronic countermeasures.Traditional LPI waveform design only uses complex modulation methods to counter reconnaissance signal processing,with little consideration given to the influence of other radiation sources in the electromagnetic environment,making it difficult for radar systems to fully utilize their low probability interception and detection performance.In actual scenarios,the LPI waveform should not only maintain the ability of adversarial reconnaissance systems,but also have the ability to adapt to the environment.Therefore,the core of the low intercept waveform design method for intentionally utilizing electromagnetic background is how to utilize environmental radiation source information in different scenarios,design low intercept waveforms that can resist detection and signal processing by reconnaissance systems in this scenario,and further improve the low probability interception and detection performance of radar systems in complex environments.The main work of the thesis is as follows:1.Firstly,by analyzing the multidimensional interception conditions of the reconnaissance system,low sidelobe antennas,waveform parameter agility,minimum radiation energy control,collaborative detection and resource management,and other low probability interception technologies were introduced for each interception condition.After analyzing and researching traditional low probability interception methods,radar signals such as continuous wave modulation,linear frequency modulation,and phase encoding are introduced to lay the foundation for designing more effective low probability interception waveforms.2.Studied the LPI waveform design method for utilizing environmental power spectrum.For scenarios with a large number of radiation sources,low probability interception methods using natural and electromagnetic environments were analyzed to estimate the power spectrum of reconnaissance receivers in the environment.A radar waveform autocorrelation template was introduced into the LPI optimization model to ensure ideal detection performance.A low probability intercept waveform optimization model was established and solved using a template matching algorithm.Finally,the power gain and interception factor obtained by waveform design are analyzed respectively.3.Studied the LPI waveform design method for utilizing multiple signal cross terms.In response to the scenario where multiple friendly clusters collaborate to detect and use radio frequency cover signals,nonlinear signal processing technologies such as energy detection and time-frequency analysis of reconnaissance systems were analyzed.Multiple signal cross power spectrum indicators and time-frequency analysis cross term indicators were established,and a low intercept waveform optimization model was established.The optimization model was solved using heuristic algorithms.Finally,the impact of utilizing multiple signal cross power spectra and time-frequency analysis cross terms on low probability interception performance was analyzed.The above work has been verified to be effective through simulation experiments.