INTRA-PULSE MODULATION FEATURE ANALYSIS AND PARAMETER ESTIMATION OF PHASE AND FREQUENCY MULTI-MODULATION SIGNAL

The parameter inversion of multi-modulation waveforms has always been a key and difficult problem in the field of electronic reconnaissance. To solve this problem, a method for intra-pulse modulation feature analysis and parameter estimation of phase and frequency multi-modulation signal is proposed in this paper. Firstly, we apply square preprocessing to eliminate the binary phase coded modulation information. Then, subpulse separation and subpulse parameter estimation are achieved by using the smooth pseudo-Wigner Ville distribution (SPWVD) and wavelet transform. Moreover, histogram statistics are introduced to improve the robustness of the method. Finally, the N-order phase difference is proposed for recovering binary phase coded sequences. Frequency domain filtering and sliding window averaging are also added to further improve the applicability of the proposed method under low signal-to-noise ratio (SNR) conditions. Simulation results suggest that the method proposed in this paper can achieve accurate signal inversion and has good robustness.