DOA Estimation for Wideband LFM Signals with a Few Snapshots

The wideband linear frequency modulation (LFM) signals are widely used in information systems. The conventional direction-of-arrival (DOA) estimation algorithms of LFM signals rely on a large number of snapshots, some of which are not reliable in numerous practical applications such as underwater array processing. To solve the above problem, we present a modified sparse iterative covariance (MSPICE)-based estimation method in fractional Fourier transform (FrFT) domain to estimate the DOA of wideband LFM signals. First, we extend the original SPICE algorithm in FrFT domain with a specific transform order for wideband LFM signals. Then, we utilize the energy centrobaric modification method to make the original SPICE more accurate without adding more computational complexity. The simulation results demonstrate the effectiveness of the proposed method.

Keywords:  Direction of arrival,,  Fractional Fourier Transform ,iterative approach ,Wideband LFM