Research On Algorithm For Waveform Detection And Interference Theory Of LPI Radar Signal

Till now, LPI radar technique develops so fast that radar signal can be transferred under the environment of negative SNR, which leads to the out of balance of electronic warfare. In order to change such situation as fast as possible, that to study the detection and interference of LPI radar signal become more and more important.The paper focuses on the study of LPI radar signal’s modulation type recognition and parameter estimation. This may promote the study and application of LPI radar signal waveform’s electronic reconnaissance algorithm. At the same time, this may promote the study of LPI radar signal’s interference and bring theory to practice.In the essay, we illustrate four types of LPI radar signals and its simulation and modeling under the environment of Gauss white noise. It includes FMCW signal, BPSK signal, Polyphase code (PI code, P2code, P3code and P4code) and Costas-coded signal. Then, common methods of LPI radar signal’s recognition and estimation are listed, and we study the methods of time-frequency analysis and HOS the most. We simulate and compare these two methods and then put forward the method basing on parallel filter arrays, higher order statistics and RBF (neural network), which increase the recognition ratio and reduce the requirement of SNR under the environment of Gauss white noise. At the end of the essay, LPI radar signal’s interference principle is to simply illustrate which may do something good to the further study.Finally, with the combination of engineering application’s requirement, the new method make four types of LPI radar signals recognized with SNR equaling to-3dB. Within the polyphase, five kinds of LPI radar signals can also be distinguished with SNR equaling to-2dB.