LFM Signal Detection, Separation And Parameter Estimation Based On Joint Time-frequency Analysis

In modern electronic battlefield, complex mixed signals usually emerge. How to recognize these signals accurately is an important task in modern electronic battles. Therefore it is considerably significant to analyze, detect, separate and estimate the radar signals.This paper is mainly based on joint time-frequency analysis. It detects, separates and estimates the linear FM signals of radar. Several kinds of radar signal models such as common linear FM pulse compressed signals, two-phase code pulse compressed signals and frequency pulse compressed signals are introduced. Then the basic knowledge of joint time-frequency analysis is demonstrated, such as Short-time Fourier transform, Wigner-Ville distribution and Wavelet transform. Main method, feature and suitable range of Wavelet transform are also introduced. Common idea and algorithm of signal detection and blind signal separation are then demonstrated. The algorithm and simulation of parameter estimation of linear FM signals are demonstrated.This paper mainly identifies linear FM signals, also called detection, parameter estimation. Wigner-Hough Distribution is used to detect the linear FM signals .An algorithm based on Wavelet transform and an algorithm based on Short-time Fourier transform are used to estimate the parameters of linear FM signals. The algorithms are proposed respectively and are then simulated.