Detection And Identification Technology Of Radar Signal Based On Time-frequency Features

With the rapid development of radar technology, advanced radar systems are coming forth. In modern battleground, more and more complicated and varied radar system and operating mode, and wide application of the advanced radar systems make modern electronic counter measures (ECM) face much denser and complex electromagnetic environment. Therefore, detecting and classification technology of radar pulse signal becomes one of the key technologies that should be solved urgently in ECM. In this paper, we mainly research the technology of radar signal detecting and pattern recognizing in the complex electromagnetic environment.In the front of this paper, several Time-frequency distribution measurement algorithms are analyzed in detail, especially The shot-time Fourier Transform(STFT) The Wigner distribution(WVD) and ambiguity function(AF),By the way the characters of these measurement algorithms are introduced.The phenomenon of Cross-terms and the technology of Kernel design for reduced interference distributions are analyzed.Then, the ambiguity functions of some radar pluses are simulated, More emphasis is put on the applicability of AF figure earmark to show the possibility of signal detection and plus type classification.Finally, some schemes of Multisignal processing measurement based on the Time-frequency distributions are conceived. The method of STFT associates with AF measurement algorithms is discussed. In the schemes, the signals are separated into the Time-frequency segments, The internal integration combining Projection Theorem is used as the "distance" in the L2Space. The value of the distance reflects the relationship between the signal models and segments. By simulations, the Multisignal processing measurement is available and flexible both in single signal condition and two signals condition.