DOA estimation of coherent wideband LFM signals based on fractional Fourier transform

Referring to the coherent wideband linear frequency modulation (LFM) signals, direction of arrival (DOA) estimation based on fractional Fourier transform (FRFT) is proposed. In this method, the observed signals are first transformed to fractional Fourier (FRF) domain, using the superior time-frequency localization, time-variant direction matrix is changed into time-invariant one. By dint of the forward/backward (FB) spatial smoothing techniques, the corresponding correlation matrix is constructed. Then the DOA of multicomponent coherent wideband LFM signals can be estimated by the traditional MUSIC algorithm simultaneously. Simulation verifies the effectiveness of the novel method.