Abstract:

Aiming at the linear frequency modulated (LFM) signal detection under the low signal-to-noise ratio, generalized S transform based on Hough transform (GSTH) which combines generalized S transform and Hough transform is put forward. Parameter characteristics of LFM signals after GST were derived in theory and the possibility of Hough transform was demonstrated, the probability density distribution functions of LFM signal and noise after GSTH are derived, the calculation method and flowchart of the detection threshold are given when conducting peak detection based on the Neyman-Pearson rule. The timefrequency focusing property of GST is used to provide nice linear characteristics which benefit line detection of Hough transform and promoted main peak while reducing the height of the second peak. The feasibility of the algorithm is tested according to the GSTH’s simulation comparisons with Wigner-Hough transform (WHT), fractional Fourier transform and periodic WHT. Besides, compared with the classical algorithm, the nice timefrequency focusing property is qualitatively described, the better detection precision and application scope of GSTH under strong noise are highlighted.