Analysis of linear and non-linear frequency modulated signals using STFT and hough transform

In this paper, a novel method is developed for the analysis and classification of frequency modulated (FM) Radar signals. The different frequency modulated radar signals considered for the classification are Linear FM (LFM), Multi-component and Non-linear FM signals. The intercepted radar signals are classified based on the Short time Fourier transform followed by the Hough Transform being applied to the projection in the time-frequency plane. Extensive simulations are carried out with different frequency modulated radar signals corrupted with additive white Gaussian noise to find the efficacy of the classification techniques. These techniques outperform the existing methods of classification and can be used at low signal-to-noise ratio (SNR) conditions.