Analysis Of Modulation Signal And Automatic Recognition

The multiformity of radar system makes it difficult to deinterleave radar signals. It is necessary for ELINT System and ESM System to have the ability to analyze and process all kinds of special radar signals quickly and correctly in order to meet the requirement of the electronic war in the future. The reliability and processing speed to deinterleave and identify radar signals can be improved by means of modulation character.Digital receiver and its forepart operational principle are discussed, then methods of Instantaneous autorelation, Short-time Fourier transform, Wigner Distribution and wavelet analysis are introduced in detail. The advantages and disadvantages and the application range of these algorithms are given. Based on the merits of these algorithms, a new method for signal modulation type analysis is presented. It is a parallel mode, that is, different algorithms match different modulated signals. Simulation results show that this scheme gets high precision. But it needs further study in algorithms to realize real-time processing. The thesis presents automatic recognizing methods of modulation types based on statistic model which can enhance processing speed. Frequency measurement through phase to recognize modulation types is another main work in this paper. Simulation results show that this method has merits of high precision with high reliability.