Robust Direction of Arrival Estimation of Wideband LFM Signals using Dechirping Algorithms with a few Snapshots in the Linear Array

Wideband linear frequency modulation (LFM) signals are widely used in systems such as radar, sonar and mobile. DOA estimation algorithms LFM signals rely on a large number of time frames (Snapshot). Therefore, they are not suitable for low power and real-time applications. In this paper, we present a low computation based estimation method based on the SPICE algorithm for linear arrays using the Fourier transform FFT. The method is to first develop the dechirping algorithm for LFM signals using the FFT converter, then modify the SPICE algorithm for uniform linear arrays (ULA), then obtain the DOA calculations for a few number of snapshots with low computational volumes. The simulation results of the proposed MSPICE algorithm (i.e. modified SPICE algorithm) show that the proposed algorithm is better than other algorithms such as MUSIC and SPICE. We have shown that the proposed method has acceptable accuracy in both low SNRs and low error in high SNRs. In addition, in terms of computational volume, it is much less than the MUSIC and SPICE methods and will have a good robustness compared to other methods.